8th international discussion meeting on relaxations in ... · glasses) nonlin-dyn (nonlinear...
TRANSCRIPT
8th International Discussion
Meeting on Relaxations
in Complex Systems
New results, Directions and Opportunities
Sunday, July 23th – Friday, July 28th, 2017
Wisła (POLAND)
www.idmrcs8.us.edu.pl
Book of Abstracts
Edited by M. Paluch & J. Knapik-Kowalczuk
ORGANIZING COMMITTEE
The conference is organized by the Institute of
Physics at the University of Silesia in Katowice
(Poland)
CHAIRPERSONS
Prof. Marian Paluch
Institute of Physics, University of Silesia, Katowice, Poland
Silesian Center for Education and Interdisciplinary Research, Chorzów, Poland
Prof. Kia L. Ngai
CNR-IPCF, Institute for Physical and Chemical Processes, Pisa, Italy
Prof. Simone Capaccioli
Dipartimento di Fisica, Università di Pisa, Pisa, Italy
Prof. Daniel Crespo
Departament de Física Aplicada, Universitat Politècnica de Catalunya, Spain
Prof. Giancarlo Ruocco
Sapienza Università di Roma, Roma, Italy
Prof. Josep Lluís Tamarit
Departament de Física i Enginyeria Nuclear,
Universitat Politècnica de Catalunya, Spain
LOCAL COMMITTEE
Marian Paluch (Conference Chairman) Andrzej Grzybowski
Katarzyna Grzybowska Marzena Rams-Baron
Justyna Knapik-Kowalczuk Kajetan Koperwas
SCIENTIFIC COMMITTEE
Affouard, F. (France) Alba-Simionesco, C. (France) Angell, A. (USA) Baschnagel, J. (France) Berthier, L. (France) Böhmer, R. (Germany) Brazhkin, V. (Russia) Capaccioli, S (Italy) Carini, G (Italy) Castner, E. W. (USA) Ciliberto, S. (France) Cipelletti, L. (France) Colmenero, J. (Spain) Crespo, D. (Spain) Cuello, G. J. (France) Di Leonardo, R. (Italy) Dalnoki-Veress, K. (Canada) Ediger, M.D. (USA) Feldman, Y. (Israel) Ferlat, G. (France) Franzese, G. (Spain) Frick, B. (France) Garcia-Ojalvo, J. (Spain) Ghosh, A. (India)
Grübel, G. (Germany) Grzybowski, A. (Poland) Guenza, M. (USA) Inaba, A. (Japan) Jain, H. (USA) Johari, G.P. (Canada) Kremer, F. (Germany) Lacabanne, C. (France) Leon, C. (Spain) Leporini, D. (Italy) Liu, A. (USA) Lunkenheimer, P. (Germany) McKenna, G.B. (USA) Micoulaut, M. (France) Morikis, D. (USA) Nagel, S.R. (USA) Ngai, K.L. (Italy) Odagaki, T. (Japan) Paluch, M. (Poland) Pardo, L. C. (Spain) Patkowski, A. (Poland) Pusztai, L. (Hungary) Ramos, M. A. (Spain) Ritort, F. (Spain) Rivera-Calzada, A. (Spain)
Rodríguez-Viejo, J. (Spain) Roland, C.M. (USA) Rössler, E. (Germany) Runt. J. (USA) Salmon, P. (UK) Samwer, K. (UK) Sastry, S. (India) Schick, C. (Germany) Schönhals, A. (Germany) Sciortino, F. (Italy) Scopigno, T. (Italy) Shirota, H. (Japan) Tamarit, J. L. (Spain) Tanaka, H. (Japan) Tanaka, K. (Japan) Tarjus, G. (France) Teixeira, J. (France) Voigtmann Th. (Germany) Wang Wei-Hua (China) Wübbenhorst, M. (Belgium) Zaccarelli, E. (Italy) Zamponi, F. (France) Zanotti, J.-M. (France) Zorn, R. (Germany)
TOPICS & CONTRIBUTIONS
Session Code (Topic)
Aging (Aging in Out of Equilibrium Systems) Alc-HB (Alcohols & H-Bonds)
Am-Pharm (Amorphous Pharmaceuticals and
Biopharmaceuticals - Physical and Chemical Stability)
Boson-P (Boson Peak)
Brillouin-LS (Brillouin Light Scattering
Microspectroscopy for Biological and Biomedical Research and Applications)
Colloids (Colloidal Systems and Dispersions) Com-Cell (Complexity and Emergent Behaviour in
Cell Populations)
Com-Phot (Complex Photonics)
Conf-TF (Confinement & Thin Films)
Cryst-Am-GT (Crystalline versus Amorphous State:
Glass Forming Ability and Stability, Glass Transition and Crystallization)
Dyn-Biomol (Dynamics of Biomolecular Systems,
Hydrated and Solvated Proteins) Dyn-Hetero (Dynamic Heterogeneity and the Glass
Transition) Gardner (Gardner Transition and Sub-Tg Dynamics in
Complex Systems)
Session Code (Topic)
H-Pressure (High Pressure Studies) IonLiq-Polym (Ionic Liquids & Ionic Polymers) Ion-Por-Nano (Ionics, Porous Ionics and Nano-
ionics)
Met-Glas (Relaxations and Diffusion in Metallic
Glasses)
Nonlin-Dyn (Nonlinear Dynamics, Nonlinear
Rheology, Theory of Nonlinear Dynamics) Polym-Dyn (Polymer Dynamics and Viscoelasticity)
Polym-Nanocom (Polymer Nanocomposites,
Structure, Molecular Mechanisms and Properties)
Proc-SR-Boson (Processes Between Structural
Relaxation and Boson Peak) Theor-Simul (Theory and Simulations of Glasses and
Glass Transition )
TV (Role of Temperature and Volume in the
Dynamics of Liquids and Polymers)
Ultras-G (Ultrastable Glasses)
Water-HB (Water and Hydrogen Bonded Systems)
SCOPE OF THE CONFERENCE
Relaxation and diffusion processes are the problems encountered in
many branches of science and engineering that deal with a variety of complex
systems and materials. The studies of the complex materials are often the key
in innovations and advancement of technology in industry. The problems
involve broad ranges of length and time scales. Although the systems are
widely different, the properties of the processes are often found to be similar.
The remarkable similarities indicate the possibility of existence of fundamental
mechanism. In spite of the advances made in the last several decades, the key
problems in many disciplines remained unsolved. Hence, there is presently
excellent opportunity for anyone in making important developments and even
breakthroughs in various fields.
For the 8IDMRCS, we shall organize an interdisciplinary program with the
purpose of harvesting new results and pointing out new directions, challenges
and opportunities in diverse areas of research of relaxations in complex
systems. The technical sessions will be organized to bring out the advances
made by colleagues from disciplines including physics, chemistry, biophysics,
biochemistry, metallurgy, rheology, and various sciences of colloids, polymers,
biopolymers, glasses, solid state ionics, ionic liquids, nanostructured matter,
nanocomposites, pharmaceuticals, food, and soft matter in general.
ISBN 978-83-226-3251-2
Opening Session 16:55 Sunday, July 23, 2017
16:55 – 17:00 WELCOME
17:00 – 17:35 PL-1 Building and Challenging Paradigms
in Glass-Forming Systems
Gregory B. McKenna (Texas Tech University, Lubbock, USA)
17:35 – 18:10 PL-2 Relaxations and their correlations
with properties in metallic glasses
Wei-Hua Wang (Chinese Academy of Sciences, Beijing, China)
18:10 – 18:45 PL-3 Equilibrium simulations of
supercooled liquids beyond laboratory
timescales
Ludovic Berthier (Université de Montpellier, Montpellier, France)
18:45 – 19:20 PL-4 Toward better understanding of the
molecular dynamics of glass-forming
liquids: high pressure dielectric studies
Marian Paluch (University of Silesia, Katowice, Poland)
20:00 – 22:00 WELCOME DINNER
PLENARY
LECTURES
PLENARY LECTURES PL-1
Building and Challenging Paradigms in Glass-Forming
Systems
Gregory B. McKenna
Dept. Chem. Engn., Texas Tech University, Lubbock, TX 79409-3121 USA
One challenge in condensed matter physics is to unravel the behavior of glasses at temperatures below
the glass transition temperature Tg. The work began in the early 20th century when scientists and
technologists faced challenges related to making large scale components for telescopes and other
precision optical instruments. This led to discoveries of surprising kinetic behaviors that were not seen
in crystalline materials, such as non-linear kinetics and large endothermic signatures in materials that
had been slowly cooled during manufacture. The completion of the signature catalogue came when
A.J. Kovacs published a major work [1] describing an extensive series of dilatometric experiments in
which he classified the unusual kinetic behavior through 1) intrinsic isotherms; 2) asymmetry of
approach; and 3) memory effect experiments. These signatures of "structural recovery" are now
widely used to understand the kinetics of glasses and form an important basis for theories of the
kinetic glass transition. These works helped to build the current paradigm of glassy materials.
Furthermore, they serve as an important framework to understand other aspects of the glass transition
itself. The understanding built on the Kovacs' signatures has permitted the present author to address
two important paradigms of the behavior of glasses. In the first instance, there is a considerable
amount of theory in the glass community that arrives at the conclusion that there exists an "ideal" glass
transition temperature as evidenced by the apparent divergence of time-scales or viscosities as the
temperature gets lower than the laboratory measured glass transition temperature. Upon working with
a glass that was aged for 20 million years (Dominican amber), we found that this specific divergence
does not occur [2]. The ability to create the experiment required an understanding of the Kovacs
signatures. In the second instance, there is considerable effort in the Soft Matter community to use
colloidal systems as simple models of glass-forming liquids. By using thermoresponsive polymer
colloidal particles, we were able to perform concentration-jump experiments [3] that are directly
analogous to the Kovacs signature experiments that are based on temperature-jumps. Of significance
is that the colloidal glasses do not exactly match the behavior of the molecular glasses. These studies
show how progress in glassy physics has been made by building on past paradigms to challenge
current paradigms.
REFERENCES
1. Kovacs, A. J., “Transition Vitreuse dans les Polyméres Amorphes. Etude Phénoménologique”, Fortschr.
Hochpolym.-Forsch., 3, 394–507 (1963).
2. Zhao, J., Simon, S. L., and McKenna, G. B., “Using 20-million-year-old amber to test the super-Arrhenius
behaviour of glass-forming systems”, Nat. Commun., 4:1783, 1–6 (2013).
3. Di, X., Win, K. Z., McKenna, G. B., Narita, T., Lequeux, F., Pullela, S. R., and Cheng, Z., “Signatures of
Structural Recovery in Colloidal Glasses”, Phys. Rev. Lett., 106, 095701 (2011).
PL-2 PLENARY LECTURES
Relaxations and their correlations with properties in
metallic glasses
Wei-Hua Wang
Institute of Physics, Chinese Academy of Sciences, Beijing 100190 China
Metallic glasses (MGs) with structure viewed approximately as dense random packing of hard spheres
offer a simple but effective model system for the study of relaxations and related issues in glass
science. Fast relaxations such as beta-relaxation, faster beta relaxation, nearly constant loss, in MGs
have been found to be closely bound up with their structural characteristics, formation, glass
transition, deformations or flow behaviors, physical and mechanical properties, crystallization,
stability, and the localized atomic diffusion motion. We present the state-of-the-art research on various
aspects of these fast localized relaxations in model metallic glass systems. We show and demonstrate
the critical importance of these fast relaxation behaviors in understanding many crucial unresolved
issues in metallic glassy physics and material sciences, including deformation, flow behavior, aging
and rejuvenation, glass transition phenomena, mechanical and physical properties, shear-banding
dynamics and deformation mechanisms, diffusions and the breakdown of Stokes-Einstein relation,
crystallization and stability of metallic glasses. We illustrate that it is an attractive prospect to
incorporate the dynamic relaxations insights into the design of MG materials with extraordinary
properties.
REFERENCES
1. Wang, Z., Ngai, K. L., Wang, W. H., Capaccioli, S., Coupling of caged molecule dynamics to Johari-
Goldstein -relaxation in metallic glasses, J Appl. Phys. 119, 024902 (2016)
2. Yu, H. B., Shen, X., Wang, Z., Gu, L., Wang, W. H., Bai, H. Y., Tensile plasticity in metallic glasses with
pronounced beta relaxations, Phys. Rev. Lett. 108, 015504 (2012).
3. Wang, Z., Sun, B. A., Bai, H. Y., and Wang, W. H., Evolution of hidden localized flow during glass-to-
liquid transition in metallic glass. Nature Communications. 5, 5823 (2014).
4. Lu, Z., Jiao, W., Wang, W. H., and Bai, H. Y., Flow unit perspective on room temperature homogeneous
plastic deformation in metallic glasses, Phys. Rev. Lett. 113, 045501 (2014).
5. Wang, W. H., Yang, Y., Nieh, T. G., Liu, C.T., On the source of plastic flow in metallic glasses: Concepts
and models, Intermetallics. 67 (2015) 81-86
6. Yu, H. B., Wang, W. H., Bai, H. Y., and Samwer, K., The β relaxation in metallic glasses, National Science
Review. 1, 429-461(2014).
7. Ketov, S. V., Sun, Y. H., Nachum, S., Lu, Z., Checchi, A., Beraldin, A. R., Bai, H. Y., Wang, W. H.,
Louzguine-Luzgin, D. V., Carpenter, M. A., and Greer, A. L., Rejuvenation of metallic glasses by non-
affine thermal strain, Nature. 524, 200-203 (2015).
8. Chen, L., Cao, C. R., Shi, J. A., Lu, Z., Sun, Y. T., Luo, P., Gu, L., Bai, H. Y., Pan, M. X., and Wang, W.
H., Fast surface dynamics of metallic glass enable superlattice-like nanostructure growth, Phys. Rev. Lett.
118, 016101 (2017)
9. Yang, X., Liu, R., Yang, M., Wang, W. H., Chen, K., Structures of local rearrangements in soft colloidal
glasses, Phsy. Rev. Lett. 116, 238003 (2016)
10. Luo, P., Li, Y. Z., Bai, H. Y., Wen, P., and Wang, W. H., Memory effect manifested by boson peak in
metallic glass, Phys. Rev. Lett. 116, 175901 (2016)
PLENARY LECTURES PL-3
Equilibrium simulations of supercooled liquids beyond
laboratory timescales
Ludovic Berthier
Laboratoire Charles Coulomb, Universite de Montpellier, Place Eugene Bataillon 34095
Montpellier Cedex 5, France
Computer simulations give unique insights into the microscopic behavior of disordered and
amorphous materials, but their typical timescales are orders of magnitude shorter than the
experimentally relevant ones. In particular, ordinary simulations of supercooled liquids cover
at most 4-5 decades of viscous slowing down, which falls far short of the 13 decades
commonly accessible in experimental studies.
We have closed this enormous gap for a class of realistic models of liquids, which we
successfully equilibrate beyond laboratory time scales by means of a swap Monte Carlo
algorithm. For some models, we achieve over 10 orders of magnitude speedup in equilibration
timescale. This numerical
advance allows us to address some outstanding questions concerning glass formation in a
dynamical range that remains inaccessible in experiments, such as the relevance of an
entropy crisis, the kinetics of ultrastable glasses, and the rheology of real glasses.
PL-4 PLENARY LECTURES
Toward better understanding of the molecular dynamics of
glass-forming liquids: high pressure dielectric studies.
Marian Paluch
Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland
In the last decade a lot of efforts have been made to investigate the effect of pressure on the
relaxation dynamics of glass-forming liquids by means of broadband dielectric spectroscopy
[1]. The aim of this presentation is to provide a comprehensive overview of the most
important findings from these studies. First, I will address the much discussed question
concerning the role played by thermal energy and density fluctuations in the tremendous
slowing down of the structural relaxation times in vicinity of glass transition. The answer to
this question will lead us further to the most intriguing and fundamental feature of the
molecular dynamics which is known as density scaling. Among other things it will be
demonstrated that the same density scaling relation is obeyed both in case of bulk and
nanoconfined liquids [2]. Considering the density scaling we will also formulate general rules
governing the behavior of isobaric, isochoric and isothermal fragilities [3].
REFERENCES 1. G. Floudas, M. Paluch, A. Grzybowski and K. L. Ngai, Molecular Dynamics of Glass-
Forming Systems, Springer-Verlag Berlin Heidelberg 2011
2. K. Adrjanowicz, K. Kaminski, M. Tarnacka, G. Szklarz, and M. Paluch, J. Phys. Chem. Lett.,
8, 696 (2017)
3. M. Paluch, E. Masiewicz, A. Grzybowski, S. Pawlus, J. Pionteck, and Z. Wojnarowska, J.
Chem. Phys., 141, 134507 (2014)
ORAL
CONTRIBUTIONS
ORAL CONTRIBUTIONS Aging-1
Oral
Aging in the glass former B2O3: a dynamic light scattering
study
Francesco Dallari, Maurizio Monti, Giulio Monaco
University of Trento, Department of physics; via sommarive 14 Povo (TN)
Glasses show a complex aging phenomenology which is still an active area of research [1].
We have studied the aging properties of the prototypical glass former B2O3 in the glass
transition temperature region using dynamic light scattering with a multispeckle setup [2, 3].
This has allowed us to obtain reliable autocorrelation functions for relaxation times up to 104
seconds.
We observed that, during aging, the autocorrelation function can be described with a stretched
exponential only at times smaller than the decay time (τ), and overall it has to be described
with a more complex functional form. Equilibrium is reached only for waiting times longer
than about 10τ. Only at equilibrium the autocorrelation function regains the stretched
exponential shape with stretching exponent (β) characteristic of the equilibrated undercooled
liquid at higher temperatures.
REFERENCES
11. Matthieu Micoulaut , Rep. Prog. Phys. 79 (2016) 066504.
12. A. Duri, H. Bissig, V. Trappe, L. Cipelletti, Phys. Rev. E (2005) 72, 051401.
13. F.Dallari, B.H. Kintov, G. Pintori, F. Riboli, F. Rossi, C. Armellini, M. Montagna, G. Monaco , Phil. Mag.
96, Issue 7-9, (2016).
Aging-2 ORAL CONTRIBUTIONS
Oral
Overly out of equilibrium: aging in active glassy matter
Liesbeth M. C. Janssen1,2
and Hartmut Löwen2
1Theory of Polymers and Soft Matter, Eindhoven University of Technology, The Netherlands
2Institute for Theoretical Physics II, Heinrich-Heine University Düsseldorf, Germany
We present particle-resolved computer simulations of a simple active model system
composed of self-propelled repulsive rods that are confined to a spherical manifold. We find
that, depending on the rod length and packing density, the system can exhibit a variety of
dynamical phases including swarming and distorted laning motion. For densely packed short
rods, we find a novel self-spinning glass phase that is characterized by strong disorder and
persistent collective rotation. By subsequently allowing the confining spherical manifold to
swell and shrink, the active glass can be melted and revitrified through the effective increase
and decrease of density, respectively. We find that this ‘breathing’ motion of the sphere gives
rise to a new type of aging dynamics, in which the system solidifies into a different but more
stable glass state after several breathing cycles. This is to be contrasted with the passive-glass
scenario, which in our model system would remain completely unaffected by repeated
swelling and shrinking. The aging behavior we observe is thus purely induced by the interplay
between the geometry and activity of the system. Such activity-driven dynamics opens up
new pathways for exploring and controlling the out-of-equilibrium behavior of topologically
constrained active and glassy matter.
ORAL CONTRIBUTIONS Aging-3
Oral
Aging kinetics and characteristic time scale of glass
Mika Kobayashi and Hajime Tanaka
Institute of Industrial Science, University of Tokyo, 153-8505 Tokyo, Japan
Aging is an out-of-equilibrium process in which a glass approaches a more “stable” state with
time. However, it has been unclear how to approach such a stable state and the property of the
final state (if it exists). We follow an aging process of a glass state by calorimetric
experiments for a few molecular liquids and find that the final state do not depend on the
thermal history. In addition, we reveal that the aging kinetics of glass-formers with different
fragilities can be scaled onto a single master curve. The characteristic time scale of aging
exhibits the temperature dependence similar to that of the structural relaxation time,
suggesting that the final state of aging is an equilibrated supercooled liquid at least for a
temperature not far from Tg. However, there remains a possibility that the structural
relaxation time does not increase as sharp as the prediction of the Vogel-Fulcher-Tammann
law for very low annealing temperatures.
REFERENCE
1. Kobayashi, M. and Tanaka, H., in preparation (2017).
Aging-4 ORAL CONTRIBUTIONS
Oral
Structural Response to Sub-Tg Annealing in a
Hyperquenched SiO2-Al2O3 Glass
Y. F. Zhang1, Y. Z. Yue
1,2
1 School of Materials Science and Engineering, Qilu University of Technology, Jinan 250353,
China
2 Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg, Denmark
We report the structural response to the sub-Tg annealing in the 69SiO2–31Al2O3 (SA) glass
that is extremely unstable against crystallization.1-3 We have found some signature for the
change of the medium-range order structure during the sub-Tg relaxation process. This is
done by using hyperquenching-annealing-differential scanning calorimetry (DSC), nuclear
magnetic resonance (NMR) and high resolution transmission electron microscopy (HRTEM).
The DSC results show a non-symmetric energy release peak with a long tail at the lower
temperature starting from the onset temperature for the hyperquenched SA glass. With
increasing sub-Tg annealing temperature and time, the tail gradually evolves into a broad
peak. This phenomenon is in strong contrast to other hyperqenched glass systems, in which
the long tail disappears with increasing sub-Tg annealing. Using NMR, we have observed that
both the 5- and 6- fold coordinated Al species decrease with sub-Tg annealing, while the 4-
fold coordinated Al species increases. This leads to the formation of the oxygen triclusters,
which can act as the mullite nucleation sites and facilitate the formation of mullite. This is
confirmed by the occurrence of the ordered structural domains at nano-scale as shown in the
HRTEM images. The ordered domains can lower the activation energy for further structural
ordering during the sub-Tg annealing, and thereby lowers the energy barrier for crystal
growth. In addition, the extremely unstable behavior of the studied glass could also be
attributed to the higher content of the 5- fold coordinated Al (~ 63%). The triclusters also
indicate the structural heterogeneity of the supercooled SA liquid. This work provides insights
into not only the structural evolution during the sub-Tg relaxation but also into the structural
origin of the extremely high unstability of the glass system against crystallization.
REFERENCES
1. Y.F. Zhang, L N Hu, S J Liu, C F Zhu, Y Z Yue, Sub-Tg enthalpy relaxation in an extremely unstable oxide
glass and its implication for structural heterogeneity. J. Non Cryst Solids. 381, 23–28 (2012).
2. Y.F. Zhang, D.H. Zhao D, Y.Z. Yue, Phase transitions and glass transition in a hyperquenched silica-
alumina glass. J Am Ceram Soc. 2017, DOI: org/10.1111/jace.14880
3. Y.F. Zhang, S.J. Liu, H.Z. Tao, D.H. Zhao, Y.Z. Yue, Enthalpy Relaxation and its Correlation to the
Medium-Range Structural Evolution in a Hyperquenched SiO2-Al2O3 System. 2017 (under review)
ORAL CONTRIBUTIONS Alco-HB-1
Invited Talk
Revisiting the dynamical processes of alcohols in the whole
supercooled domain
C. Alba-Simionesco1, F. Porcher
1, S.Longeville
1, T. Hecksher
2, K. Niss
2, M.
Hartmann-Jensen1,2
, R.Richert3
1Laboratoire Léon Brillouin ,CNRS /CEA -UMR 12, CEA Saclay, 91191 Gif-sur-Yvette
Cedex, France
2DNRF Centre “Glass and Time”, IMFUFA, Department of Sciences, Roskilde University,
Postbox 260,
DK-4000 Roskilde, Denmark
3Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona
85287, U.S.A.
Hydrogen bonded liquids are most of the time very good glassformers, they present all the
salient features of other molecular liquids, however the presence of hydrogen bond induces
extra phenomena. The first consequence is the self-association of molecules and the
structural dynamics is strongly affected by the 3D fluctuating network of the Hydrogen bonds
that are continuously broken and formed; H bonds are randomly distributed in the system as
for glycerol, or more specific shape as ring or chains for mono alcohols, always
counterbalanced by the steric hindrance and flexibility of the alkyl chains. Recent studies on
mono alcohols by some of the authors focused on the impact of their specific local
organization on the correlation between the low frequency Debye peak measured by dielectric
spectroscopy and excess low frequence modes measured by mechanical experiments.
However, no systematic trends were observed so far related to the size, the number and the
shape of such clusters. We propose to revisit the T-dependence of the structure and the
dynamics of some monohydroxy alcohols and then question the case of other hydrogen
systems.
Alco-HB-2 ORAL CONTRIBUTIONS
Invited Talk
How the molecular architecture influence the relaxation
properties of alcohols?
Sebastian Pawlus
Institute of Physics & Silesian Center for Education and Interdisciplinary Research,
University of Silesia, ul. 75 Pulku Piechoty 1A, 41-500 Chorzow Poland
Alcohols are the family of materials differing not only with the number of hydroxyl group in
the molecular structure. Also the variation of the position of the OH groups on the alkyl
backbone, length of this backbone and the existence of additional pendant groups are
characteristic for this class of liquids. All these variations of the molecular structure, and
consequently hydrogen bonded architecture, results in difference in the properties of various
alcohols. However, these differences affect the features of the material in diverse manner.
Consequently, understanding which factor is of the essential meaning e.g. for the molecular
dynamics of the material, remains crucial for searching and development of materials with
best properties for industry or medicine applications.
During presentation it will be showed how the variation of the molecular size, location and
number of the hydroxyl groups influence the molecular dynamics of some alcohols, studied
with use of the dielectric spectroscopy. Results for monohydroxy alcohols and diols studied at
various temperature conditions will be compared.
Some dissimilarities of the features between seemingly similar materials become visible only
at elevated pressure. Therefore, results collected at ambient pressure will be compared with
the data measured at high pressure conditions to demonstrate possible differences.
REFERENCES
1. M. Wikarek, S. Pawlus, S. N. Tripathy, A. Szulc, M. Paluch „How Different Molecular Architectures
Influence the Dynamics of H-Bonded Structures in Glass-Forming Monohydroxy Alcohols” J. Phys. Chem.
B 120, 5744 (2016)
2. S. Pawlus, M. Wikarek, C. Gainaru, M. Paluch, and R. Böhmer “How do high pressures change the Debye
process of 4-methyl-3-heptanol?” J. Chem. Phys. 139, 064501 (2013)
3. C. Gainaru, M. Wikarek, S. Pawlus, M. Paluch, R. Figuli, M. Wilhelm, T. Hecksher, B. Jakobsen, J. C.
Dyre, R. Böhmer „Oscillatory shear and high-pressure dielectric study of 5-methyl-3-heptanol” Colloid
Polym. Sci. 292, 1913 (2014)
4. S. Pawlus, A. Grzybowski, M. Paluch and P. Wlodarczyk „Role of hydrogen bonds and molecular structure
in relaxation dynamics of pentiol isomers” Phys. Rev. E 85, 052501 (2012)
ORAL CONTRIBUTIONS Alco-HB-3
Invited Talk
Mechanical signatures of supra-molecular structures in
hydrogen-bonded systems
Tina Hecksher
Glass and Time, IMFUFA, Department of Science and Environment, Roskilde University,
P.O. Box 260, DK-4000 Roskilde, Denmark
For a long time it was a mystery why the prominent dielectric loss-peak in mono-alcohols
apparently had no counterpart in other experimental probes1, until it was discovered that the
shear mechanical spectra of mono-alcohols in fact do display a subtle, but clear, feature
similar to that of short-chain polymers2,3
. Both dielectric and rheological observations are
consistent with the formation linear hydrogen-bonded structures, which are further evidenced
by a pre-peak in the structure factor.
Recent studies show that this rheological signature is more general; we found that the amine
and thiol derivatives of 2-ethyl-1-hexanol (i.e., systems with weaker hydrogen bonds) showed
a similar rheological feature4 and that also the density dynamics is affected
5. In addition, we
now have evidence of a slow mode in the shear mechanical spectra of poly-alcohols6,
although poly-alcohols normally have no anomalous slow dielectric spectral feature.
Together these pieces of the puzzle point to a mechanism behind the slow dynamics that is
less transient than previously thought.
REFERENCES
1. R. Böhmer, C. Gainaru, and R. Richert, Structure and dynamics of monohydroxy alcohols—Milestones
towards their microscopic understanding, 100 years after Debye, Phys. Rep. 545, 125-195 (2014)
2. C. Gainaru, R. Figuli, T. Hecksher, B. Jakobsen, J. C. Dyre, M. Wilhelm, and R. Böhmer, A., Shear-
Modulus Investigations of Monohydroxy Alcohols: Evidence for a Short-Chain-Polymer Rheological
ResponseTitle, Phys. Rev. Lett. 112, 098301 (2014).
3. T. Hecksher and B. Jakobsen, Communication: Supramolecular structures in monohydroxy alcohols:
Insights from shear-mechanical studies of a systematic series of octanol structural isomers, J. Chem. Phys.,
141, 101104 (2014). T. Hecksher, Communication: Linking the dielectric Debye process in monoalcohols to
density fluctuations, J. Chem. Phys., 144, 161103 (2016).
4. K. Adrjanowicz, B. Jakobsen, T. Hecksher, K. Kaminski, M. Dulski, M. Paluch, and K. Niss,
Communication: Slow supramolecular mode in amine and thiol derivatives of 2-ethyl-1-hexanol revealed by
combined dielectric and shear-mechanical studies, J. Chem. Phys., 143, 181102 (2015).
5. T. Hecksher, Communication: Linking the dielectric Debye process in monoalcohols to density fluctuations,
J. Chem. Phys., 144, 161103 (2016).
6. M. H. Jensen, T. Hecksher, C. Gainaru, C. Alba-Simionesco, and K. Niss, Slow polymer-like rheological
mode in glycerol and glycerol water mixtures, in preparation
Alco-HB-4 ORAL CONTRIBUTIONS
Invited Talk
The Debye process in dielectric spectroscopy
and dynamic light scattering
Jan Gabriel, Florian Pabst, Till Böhmer and Thomas Blochowicz
Technische Universität Darmstadt, Hochschulstr. 6-8, 64289 Darmstadt
Although the Debye process in monohydroxy alcohols is known for a long time, its molecular
origin is still a matter of ongoing debate [1], but in general it is assigned to the relaxation of
transient supramolecular structures that form due to H-bonding [2]. For a while it seemed that
only dielectric specroscopy shows such a pronounced feature connected to the Debye process,
but recently signatures of a Debye relaxation were reported in investigations of the shear
modulus of monoalcohols [3]. Moreover it was reported that a Debye like relaxation can be
seen by light scattering in water [4] and H-bonding imidazoles [5].
We will discuss the appearance of the Debye relaxation in depolarized dynamic light
scattering and dielectric spectroscopy and will present new light scattering data on a series of
monoalcohols. When discussing depolarized dynamic light scattering one faces the problem
that typical monoalcohols produce only very weak depolarized signal. Therefore we first
discuss improvements of our experimental setup that allow us to perform depolarized photon
correlation spectroscopy on weak scatterers and to descriminate signals of weak processes
from artefacts. Then we quantitatively compare how the Debye relaxation appears in light
scattering and dielectric spectroscopy and discuss possible implications of our findings
concerning the physical nature of this process.
REFERENCES
1. Böhmer, R., Gainaru, C., Richart, R., Structure and dynamics of monohydroxy alcohols-milestones towards
their microscopic understanding, 100 years after debye, Physics Reports. 545(4):125-195 (2014).
2. Gainaru, C., Meier, R., Schildmann, S., Lederle, C., Hiller, W., Rössler, E. A., Böhmer, R., Nuclear-
magnetic-resonance measurements reveal the origin of the debye process in monohydroxy alcohols, Phys
Review Letters. 105(25) (2014).
3. Gainaru, C., Figui, R., Hecksher, T., Jakobsen, B., Dyre J. C., Wilhelm, M., Böhmer, R., Shear-modulus
investigations of monohydroxy alcohols: Evidence for a short-chain-polymer rheological response, Physical
Review Letters. 112(9) (2014).
4. Hansen, J. S., Kisliuk, A., Sokolov, A. P., Gainaru, C., Identification of structural relaxation in the dielectric
response of water, Phys. Rev. Lett. 116:237601+ (2016).
5. Wang, Y., Griffin, P. J., Holt, A., Fan, F., Sokolov, A. P., Observation of the slow, Debye-like relaxation in
hydrogen-bonded liquids by dynamic light scattering, The Journal of Chemical Physics. 140, 104510
(2014).
ORAL CONTRIBUTIONS Alco-HB-5
Invited Talk
Asymmetric mixtures involving monohydroxy alcohols
S. Peter Bierwirth, Catalin Gainaru, Roland Böhmer
Technische Universität Dortmund, 44221 Dortmund, Germany
Owing to their strong Debye-type dielectric relaxation, monohydroxy alcohols – which in this
respect are similar to water – are studied at least since the days of Debye [1]. Nevertheless,
the microscopic origin of their Debye-type relaxation has remained disputed for a long time.
Recent approaches involving a large number of different techniques and scientific work
groups have shed new light on this issue [2]. This presentation will focus on some recent
developments in this area, with a focus on asymmetric mixtures involving monohydroxy
alcohols.
Work supported by the Deutsche Forschungsgemeinschaft under Grant No. BO1301/14-1.
REFERENCES
1. P. Debije, Zur Theorie der anomalen Dispersion im Gebiete der langwelligen elektrischen Strahlung, Verh.
Dtsch. Phys. Ges. 15, 777 (1913).
2. For a recent review, see for instance R. Böhmer, C. Gainaru, R. Richert, Structure and dynamics of
monohydroxy alcohols – milestones towards their microscopic understanding, 100 years after Debye, Phys.
Rep. 545, 125 (2014) and references cited therein.
Alco-HB-6 ORAL CONTRIBUTIONS
Invited Talk
On the non-exponentiality of the dielectric Debye-like
relaxation of monoalcohols
S. Arrese-Igor1, A. Alegría
1,2 , and J. Colmenero
1,2,3
1 Centro de Física de Materiales CSIC-UPV/EHU and MPC,
2 Dpto de Física de Materiales UPV/EHU,
3 Donostia International Physics Center DIPC,
Paseo Manuel Lardizabal 5, 20018 San Sebastián, Spain
The Debye-like relaxation arising as a consequence of hydrogen bonding in Monoalcohols
(MA) has been the object of intense research throughout the last century [1]. To time, most
Debye relaxations have been reported to be exponential relaxations. Wang et al. [2], however,
reported non-pure exponential behaviour for the most prominent and slowest relaxation
component in 2-butyl-1-octanol and 2-hexyl-1-decanol, two relatively long alkyl chain MAs
(and hence here the use of “Debye-like”). The prevailing picture today is that Debye-like
relaxation originates from the rearrangement of the hydrogen bond structures, either by re-
structuring transient chain-like dynamics or by fluctuation of the net dipolar moment as a
result of the recombination of the hydrogen bond structure. We have investigated the Debye-
like relaxation in a series of MAs by broadband dielectric spectroscopy (BDS) and thermally
stimulated depolarization current techniques (TSDC) in order to get further insight on the
time dispersion of this intriguing relaxation. The analysis of partial polarization TSDC data
provides a detailed study of the spectral shape or characteristic time distribution of relaxations
[3], allowing us to explore to which extent the analogy of polymer chain dynamics for the
relaxation of Hydrogen bonded chainlike aggregates is compatible with the observed Debye-
like relaxation.
REFERENCES
1. Böhmer, R., Gainaru, C., and Richert, R.. Structure and Dynamics of Monohydroxy Alcohols - Milestones
Towards their Microscopic Understanding, 100 Years after Debye. Phys. Rep. 545, 125 (2014).
2. Gao, Y., Tu, W., Chen, Z., Tian, Y., Liu, R., and Wang, L. M.. Dielectric Relaxation of Long-chain Glass-
forming Monohydroxy Alcohols. J. Chem. Phys.139, 164504 (2013).
3. Arrese-Igor, S., Alegría, and A., Colmenero, J.. Polymer Chain Dynamics: Evidence of Nonexponential
Mode Relaxation Using Thermally Stimulated Depolarization Current Techniques. Phys. Rev. Lett., 113,
078302 (2014). Chain Dynamics on Crossing the Glass Transition: Nonequilibrium Effects and Recovery of
the Temperature Dependence of the Structural Relaxation. ACS Macroletters, 3,1215-1219 (2014).
ORAL CONTRIBUTIONS Alco-HB-7
Invited Talk
Change of hydrogen bonds geometry in mono-alcohols as
possible origin of Debye Mode
Patryk Wlodarczyk1, Lukasz Hawelek
1, Agnieszka Wlodarczyk
2
1) Institute of Non-Ferrous Metals, ul. Sowinskiego 5, 44-100 Gliwice, Poland
2) University of Silesia, Department of Animal Histology and Embryology, ul. Bankowa
9, 40-007 Katowice, Poland
Aim of the study was to develop model that can explain origin of Debye Mode in mono-
alcohols. To this end, molecular dynamic of different systems based on 2-ethyl-1-hexanol was
performed. The 2-ethyl-1-hexanol at ambient and elevated pressure, 2-ethyl-1-hexanol in
mixtures with BuBr, 2-ethyl-1-hexanethiol and 2-ethyl-1-hexaneamine were examined. By
comparison of theoretical results to the experimental data, it was found that the Debye process
should be cluster size independent. It was found that suppression of dielectric strength of
Debye relaxation can be related to the different theoretical scenarios, when average cluster
size is being increased or decreased. Moreover, the crucial parameter for Debye mode
behavior was found to be amount of low molecular clusters i.e. from dimers to heptamers.
Additional quantum mechanical studies within the framework of density functional theory
(DFT) with use of natural bond orbitals analysis have shown that the geometry of hydrogen
bonds in mono-alcohols is very sensitive to the cluster length. In the case of dimer, the angle
in hydrogen bond O-H…
O is close to 90
htly weaker in larger
clusters. Therefore, the change of hydrogen bonds’ geometry during cluster reformation
causes change of HB geometry and in consequence leads to the fluctuations of dipole
moment. Such change of HB geometry could be the origin of Debye mode in the dielectric
spectra of mono-alcohols.
Alco-HB-8 ORAL CONTRIBUTIONS
Invited Talk
Liquid dynamics during nucleation and crystal growth in a
hydrogen-bonded liquid
Alejandro Sanz and Kristine Niss
“Glass and Time”, IMFUFA, Department of Science and Environment, Roskilde University,
P.O. Box 260, DK-4000 Roskilde, Denmark
The connection between the liquid’s dynamics and the crystalline development in glycerol, a
hydrogen-bonded liquid, is studied by means of dielectric spectroscopy. An appropriate
thermal protocol allowed us to control the nucleation and crystal growth processes. Our
results are consistent with the transformation of liquid glycerol into the standard orthorhombic
state and we do not find any evidence suggesting that it transforms into a peculiar solid phase
with distinct structural or mechanical properties. As we have recently reported [1], in one
single case we observed a rare event in which the transformation into the crystalline state was
frustrated at the very late stages. A subtle balance between kinetic and thermodynamic effects
may explain the occurrence of sporadic aborted crystal growth phenomena with lack of
reproducibility. We discuss the coupling between dynamic properties, such as dielectric
relaxation time, viscosity and self-diffusion coefficient, and the characteristic time of crystal
growth. We find a scaling exponent of -0.85 when the crystal growth time is plotted against
the self-diffusion coefficient in a log-log representation, confirming that the liquid’s dynamics
is the principal factor governing the crystal growth in glycerol near Tg.
REFERENCES
1. Sanz, A., Niss, K., Liquid dynamics in partially crystalline glycerol, Journal of Chemical Physics. 146,
044502 (2017).
ORAL CONTRIBUTIONS Alco-HB-9
Oral
Elastic properties of molecular glass-forming liquids with
and without hydrogen bonds under high pressure
I.V. Danilov1,2
, E.L. Gromnitskaya1, A.G. Lyapin
1,2, V.V. Brazhkin
1
1Institute for High Pressure Physics, RAS, Troitsk, Moscow, 108840, Russia
2Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, 141700,
Russia
Intermolecular interaction in most of molecular liquids is caused by the van der Waals
forces, but the presence of hydrogen bonds changes the energy landscape [1-3]. We present
ultrasonic study of elasticity of liquid and glassy propylene carbonate (without H-bonds) and
glycerol (with H-bonds) under high pressure with the purpose to clarify the role of hydrogen
bonds in intermolecular interaction.
The elastic moduli of both liquid and glassy glycerol at ambient pressure are
significantly (approximately by 2-2.5 times) higher than moduli of the respective phases of
PC. It indicates essential contribution of hydrogen bonds to the intermolecular interaction in
glycerol. However, pressure derivatives of bulk modulus in the liquid state are quite similar
for PC and glycerol (B’8), what shows the similar nature of central forces part in
interparticle potential. In glassy state with increasing pressure bulk and shear moduli of these
materials increase at the same rate. Poisson’s ratio at the liquid nitrogen temperature of glassy
PC 0.36 and glycerol’s 0.34. Large values of Poisson’s ratio indicate a significant
contribution of non-central forces to the intermolecular potential in both glasses. However,
value of glycerol is lower than PC’s, what may be related to central ion-ion forces in O-H—
O hydrogen bonds in glycerol. Temperature dependence of elastic properties was studied
while heating from 77 K to the room temperature 295 K under pressure, where we observed
glass-liquid transitions. While bulk modulus of PC decreases with increasing temperature
nearly linearly and doesn’t have large anomalies in the transition region, bulk modulus of
glassy glycerol has slight temperature dependence, but drops drastically when glycerol
becomes liquid.
REFERENCES
1. Pronin, A., Kondrin, M., Lyapin, A., Brazhkin, V., Volkov, A., Lunkenheimer, P., Loidl, A., Phys. Rev. E
81, 041503 (2010).
2. Kondrin, M., Gromnitskaya, E., Pronin, A., Lyapin, A., Brazhkin, V., Volkov, A., J. Chem. Phys. 137,
084502 (2012).
3. Reiser, A., Kasper, G., Europhys. Lett. 76, 1137 (2006).
Alco-HB-10 ORAL CONTRIBUTIONS
Oral
Stress-Structure Coupling of Liquid 1-Alcohols
Tsuyoshi Yamaguchi
Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya, Aichi, 464-
8603, Japan
1-alcohol is a class of amphiphilic molecules in which a hydrophilic OH group is attached to
a hydrophobic alkyl chain. In liquid phase, the 1-alcohols form a characteristic linear
hydrogen-bonding network structure, and it is interesting how the network structure affects
macroscopic properties of liquids such as shear viscosity.
In addition to the strong main peak common to other liquids, the static structure factor of 1-
alcohols exhibits the prepeak at the wavenumber lower than that of the main peak. The
prepeak appears as a broad shoulder in methanol, while a distinct peak is observed in higher
alcohols. The prepeak is known to represent the correlation between the hydrogen-bonding
network chains. In this work, the effects of the network structure of 1-alcohols on the shear
viscosity were investigated through the coupling between the shear stress and the density
mode at the prepeak.
The analysis was performed with molecular dynamics (MD) simulation in two different
ways. The first one is the comparison between the spectra of the complex shear viscosity and
the intermediate scattering function at the prepeak, which were applied to 1-butanol, 1-
octanol, and 1-dodecanol [1]. The relaxation of the complex shear viscosity was bimodal.
The relaxation frequency of the slower mode agreed with that of the squared intermediate
scattering function at the prepeak, while the faster mode with that at the main peak.
The cross correlation between the shear stress and the prepeak structure was evaluated
directly in the case of liquid methanol. The time scale of the slowest relaxation mode of the
shear stress was several ps, and the cross correlation between the prepeak and the shear stress
was also observed in the same time scale. The sign of the cross correlation indicates that the
hydrogen-bonding network aligns along the expansion axis under the pure-shear deformation.
The analysis based on MD simulation suggests that the slowest mode of the shear relaxation
of liquid 1-alcohols is assigned to the dynamics of the network structure. Its experimental
examination is also in progress, which we would like to present at the conference.
REFERENCES
1. YAMAGUCHI, T., Viscoelastic relaxations of high alcohols and alkanes: Effects of heterogeneous structure
and translation-orientation coupling, J. Chem. Phys. 146, 094511 (2017).
ORAL CONTRIBUTIONS AM-Pharm-1
Invited Talk
Predicting the physical stability of amorphous solid
dispersions
Raj Suryanarayanan (Sury)
College of Pharmacy, University of Minnesota, Minneapolis, MN 55455
Amorphous solid dispersions (ASDs), while having the potential to enhance oral
bioavailability, can be physically unstable leading to drug crystallization. Accelerated
stability testing of ASDs provides an avenue to predict the physical stability under storage
conditions of pharmaceutical interest. The influence of sorbed plasticizer (water or glycerol)
concentration on the molecular mobility and the crystallization behavior in model amorphous
drug and ASDs was investigated. The temperature scaling (Tg/T) enabled the simultaneous
evaluation of the effects of plasticizer content and temperature on relaxation time. The
plasticization effect explained both the increase in mobility and the decrease in crystallization
onset temperature. The temperature dependencies of the α-relaxation time as well as the
crystallization time were unaffected by the plasticizer content. The drug crystallization was
well coupled to molecular mobility and was unaltered at plasticizer concentration up to ~ 2%.
The acceleration in crystallization brought about by plasticizer expedited the determination of
the coupling between molecular mobility and crystallization. As a result, we were able to
predict the physical stability of the unplasticized ASD. This approach is especially useful for
ASDs with high polymer content where drug crystallization is extremely slow at relevant
storage temperature. Crystallization, acclereated by water vapor sorption, can also serve as an
effective preliminary screening tool to rapidly evaluate and rank order the physical stability of
ASDs.
REFERENCES
1. Mehta, M., Kothari, K., Ragoonanan, V. and Suryanarayanan, R., 2016. Effect of water on molecular
mobility and physical stability of amorphous pharmaceuticals. Molecular Pharmaceutics, 13, pp.1339-1346.
2. Mehta, M. and Suryanarayanan, R., 2016. Accelerated physical stability testing of amorphous
dispersions. Molecular Pharmaceutics, 13, pp.2661-2666.
3. Mistry, P., Amponsah-Efah, K.K. and Suryanarayanan, R., 2017. Rapid assessment of the physical stability
of amorphous solid dispersions. Crystal Growth & Design, 17, pp. 2478-2485
4. Fung, M., Suryanarayanan, R., 2017. The use of a plasticizer for physical stability prediction of amorphous
solid dispersions. Submitted.
AM-Pharm-2 ORAL CONTRIBUTIONS
Invited Talk
Transformations of amorphous states during
pharmaceutical processing
Evgenyi Shalaev1,2
, Anatoly Politov3,4
, Elena Boldyreva3,4
*,
1-Allergan Inc, Irvine, CA 92612 USA, 2 – University of Minnesota, Minneapolis, MN 55455
USA, 3 – Institute of Solid State Chemistry and Mechanochemistry, SB RAS, ul. Kutateladze,
19, Novosibirsk 630128 Russia, 4 – Novosibirsk State University, ul. Pirogova, 2,
Novosibirsk 630090 Russia
Amorphous materials are ubiquitous in pharmaceutical products, ranging from small molecular
weight drugs, such as freeze-dried antibiotics and solid dispersions of drug molecules in
polymers, to viral vaccines and gene delivery vectors imbedded into carbohydrate glasses.
Essentially all typical processing unit operations can create partially or completely amorphous
materials, either intentionally, or unintentionally. This presentation addresses new findings on
amorphous states that are produced by several processes, including lyophilization (freeze-drying),
milling, hot-melt extrusion, and ultrasonic treatment. The following essential topics are
addressed: (i) why water-to-ice transition during freezing of typical pharmaceutical solutions is
always incomplete: beyond glass transition; (ii) large-scale inhomogeneity in aqueous glasses and
stability of pharmaceutical proteins; (iii) practical significance of the non-equilibrium nature of
glasses: impact of the thermal and processing history on stability; (iv) the role of organic co-
solvents and/or co-solutes in creating amorphous materials with controlled properties by freeze-
drying; (v) amorphization vs. fragile comminution by varying the conditions of mechanical and
ultrasonic treatment; (vi) the role of the processing conditions (e.g., cooling protocol, humidity)
and the starting polymorphs in the formation of amorphous states in the melt-quenching process.
REFERENCES
1. Chou, S.G., Soper, A.K., Khodadadi, S., Curtis, J.E., Krueger, S., Cicerone, M.T., Fitch, A., Shalaev, E.Y.
Pronounced micro-heterogeneity in a sorbitol-water mixture observed through variable temperature neutron
scattering, J. Phys. Chem. B, 116, 4439–4447 (2012). (b) Authelin, J-R, MacKenzie, A.P., Rasmussen,
D.H., Shalaev, E.Y. Water clusters in amorphous pharmaceuticals, J. Pharm. Sci., 103, 2663–2672 (2014).
(c) Khodadadi, S., Clark, N.J., McAuley, A., Cristiglio, V., Curtis, J.E., Shalaev, E.Y., Krueger, S.
Influence of sorbitol on protein crowding in solution and freeze-concentrated phases. Soft Matter, 10, 4056-
4060 (2014). (d) Shalaev, E., Soper, A.K. Water in a soft confinement: structure of water in amorphous
sorbitol. J. Phys. Chem. B. DOI: 10.1021/acs.jpcb.6b06157 (2016).
2. Politov, A. A., Kostrovskii, V. G., & Boldyrev, V. V. Conditions of preparation and crystallization of
amorphous paracetamol, Rus. J. Phys. Chem. A, 75, 1903-1911 (2001); McGregor, L., Rychkov, D. A.,
Coster, P. L., Day, S., Drebushchak, V. A., Achkasov, A. F., G.S. Nichol, C.R. Pulham & Boldyreva, E. V.,
A new polymorph of metacetamol, CrystEngComm, 17, 6183-6192 (2015);
3. Boldyreva, E. Non-ambient conditions in the investigation and manufacturing of drug forms. Current
Pharm. Design, 22, 4981-5000 (2016).
ORAL CONTRIBUTIONS AM-Pharm-3
Invited Talk
Molecular factors governing the liquid and glassy states
recrystallization of anti-inflammatory drug in binary
mixtures with excipients of different molecular weights
K. Grzybowska,* K. Chmiel, J. Knapik-Kowalczuk, A. Grzybowski, K. Jurkiewicz, and
M. Paluch
Institute of Physics, University of Silesia, ul. Uniwersytecka 4, 40-007 Katowice, Poland
Silesian Center for Education and Interdisciplinary Research, ul. 75 Pułku Piechoty 1a,
41-500 Chorzów, Poland
We present analyses of the physical stability and its correlations with the molecular dynamics
performed for the binary mixtures of anti-inflammatory drugs with large molecular weight
polymer: polyvinylpyrrolidone (PVP) and small molecular weight compound
octaacetylmaltose (acMAL) in the wide temperature range in both the supercooled and glassy
states. There are still not many such studies, which are required to gain better insights into
correlations between molecular mobility and crystallization of pharmaceuticals above and
below their glass transition temperatures Tg. In this context, our findings recently reported in
[1] are very important, because we have established that PVP K30 more effectively stabilizes
celecoxib (CEL) in the supercooled liquid state than small molecular weight acMAL, and the
stabilization effects of PVP and acMAL on CEL are reversed in the glassy state. It should be
emphasized that the examined crystallization inhibitors are also very interesting from the
cognitive point of view, because earlier investigations showed that molecules of CEL can
interact with the molecules of acMAL and PVP via hydrogen bonds formed between the same
functional groups of drug and crystallization inhibitors (N–H···C=O). Moreover, in contrast
to acMAL, PVP exerts an antiplasticization effect on CEL. Therefore, our comparative
studies aimed at determining the effectiveness of the crystallization inhibition of supercooled
and glassy CEL by PVP and acMAL also provided a better understanding of interplaying
molecular factors that determine the recrystallization tendency of investigated binary systems,
and shed a new light on the molecular mechanisms underlying methods for predicting the
physical stability of the binary mixtures CEL+PVP and CEL+acMAL in both the supercooled
and glassy states.
REFERENCES
1. Grzybowska, K., Chmiel, K., Knapik, J, Grzybowski, A. Jurkiewicz, K., and Paluch, M. Mol.
Pharmaceutics, 14, 1154−1168 (2017)
AM-Pharm-4 ORAL CONTRIBUTIONS
Invited Talk
The role of molecular mobility in designing amorphous
solid dispersions
Khushboo Kothari
Takeda Pharmaceutical Ltd. Cambridge, MA, USA
Amorphous solid dispersions offer a potential to enhance the solubility and consequently the
oral bioavailability of poorly water soluble compounds.1 However, the physical instability
associated with amorphous drugs remains a significant challenge in developing commercial
solid dispersions. Several comprehensive studies have investigated the role of thermodynamic
and kinetic factors governing the stabilization of drugs in solid dispersions. In particular, the
role of molecular mobility as a predictor of physical stability of amorphous pharmaceuticals
has been studied in detail.2,3
Identifying a polymer which will physically stabilize the drug
(i.e. prevent drug crystallization) during processing and storage (shelf-life) of the dosage form
is crucial for developing robust solid dispersions. The ideal polymer should be effective at a
low concentration for achieving high drug loading while maintaining an acceptable size of the
dosage form. Rationalizing polymer selection by understanding its influence on the molecular
mobility and consequently the physical stability is the first step towards designing robust solid
dispersions.4, 5, and 6
REFERENCES
1. Serajuddin, A., Solid Dispersion of Poorly Water‐Soluble Drugs: Early Promises, Subsequent Problems,
and Recent Breakthroughs. Journal of pharmaceutical sciences 1999, 88 (10), 1058-1066.
2. Bhugra, C.; Pikal, M. J., Role of Thermodynamic, Molecular, and Kinetic Factors in Crystallization from
the Amorphous State. Journal of pharmaceutical sciences 2008, 97 (4), 1329-1349
3. Kothari, K.; Ragoonanan, V.; Suryanarayanan, R., Influence of Molecular Mobility on the Physical Stability
of Amorphous Pharmaceuticals in the Supercooled and Glassy States. Molecular pharmaceutics 2014.
4. Kothari, K.; Ragoonanan, V.; Suryanarayanan, R., The role of drug-polymer hydrogen bonding interactions
on the molecular mobility and physical stability of nifedipine solid dispersions. Molecular pharmaceutics
2014.
5. Kothari, K.; Ragoonanan, V.; Suryanarayanan, R., The role of polymer concentration on the molecular
mobility and physical stability of nifedipine solid dispersions. Molecular pharmaceutics 2014.
6. Mistry, P.; Mohapatra, S.; Gopinath, T.; Vogt, F.; Suryanarayanan, R., Role of the strength of drug-polymer
interactions on the molecular mobility and crystallization inhibiton in Ketoconazole Solid Dispersion, 2015.
ORAL CONTRIBUTIONS AM-Pharm-5
Invited Talk
Characterization of Amorphous Solids Using Solid-State
NMR Spectroscopy
Eric Munson
Department of Pharmaceutical Sciences, College of Pharmacy,
789 South Limestone, Lexington, KY 40536
Advanced analytical techniques can provide unique insight into the composition and
properties of pharmaceutical formulations. In particular, both structural and mobility
information can be obtained about the formulations, but the challenge is to relate that
information to functional properties such as physical and chemical stability, dissolution rate,
and processing parameters. We are currently using solid-state NMR spectroscopy
(SSNMR)as a method of characterizing amorphous forms of drugs as well as amorphous solid
dispersions. Topics that will be discussed in this presentation include the identification of
small amounts of crystalline material in an amorphous formulation, the role of hydrogen
bonding interactions in the stabilization of amorphous solid dispersions, and the use of
relaxation times to identify phase separation and mobility in these matrices. For example, we
have found that hydrogen bonding plays a significant role in stabilizing drug formulations,
and that water interferes with that stabilization by both lowering the glass transition
temperature and reducing the hydrogen bonding interactions. These principles have also been
applied to study amorphous protein formulations that are stabilized with amorphous sugars.
Eric Munson is a partial owner of Kansas Analytical Services, a company that provides solid-
state NMR services to the pharmaceutical industry. The results presented here are from his
academic work at the University of Kentucky, and no data from Kansas Analytical Services
are presented here. Funding was provided by the Center for Pharmaceutical Development, an
NSF Industry-University Cooperative Research Center.
REFERENCES
1. Yuan, X.; Sperger, D.; Munson, E.J. “Investigating Miscibility and Molecular Mobility of Nifedipine-PVP
Amorphous Solid Dispersions Using Solid-State NMR Spectroscopy” Molecular Pharm., 11, 329-337
(2014).
2. Yuan, X.; Xiang, T.-X.; Anderson, B.; Munson, E.J. “Hydrogen Bonding Interactions in Amorphous
Indomethacin and Its Amorphous Solid Dispersions with Poly(vinylpyrrolidone) and Poly(vinylpyrrolidone-
co-vinyl acetate) Studied Using 13C Solid-State NMR” Molecular Pharm., 12, 4518-4528 (2015).
3. Mensink, M.A.; Nethercott, M.; Hinriches, W.L.; van der Voort Maarschalk, K.; Frijlink, H.W.; Munson,
E.J.; Pikal, M.J. “Influence of Miscibility of Protein-Sugar Lyophilizates on Their Storage Stability” AAPS
J, (2016).
AM-Pharm-6 ORAL CONTRIBUTIONS
Invited Talk
Insight into proton transfer reaction in amorphous
bicalutamide
M. Rams-Baron, P. Włodarczyk, Z. Wojnarowska, M. Dulski, M. Paluch
Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland
Silesian Center for Education and Interdisciplinary Research, 75 Pulku Piechoty 1a, 41-500
Chorzow, Poland
Institute of Non-Ferrous Metals, Sowinskiego 5, 44-100 Gliwice, Poland
Institute of Material Sciences, University of Silesia, 75 Pulku Piechoty 1a, 41-500 Chorzow,
Poland
The occurrence of tautomerization in drugs, i.e. proton transfer from one place to another, must be
precisely predicted during drug development and strictly controlled at all stages of drug
manufacturing and administration. It becomes a necessity because different tautomeric forms of
active pharmaceutical ingredients (APIs) may possess distinct physicochemical features, diverse
biological reactivates and consequently their efficacy can vary distinctly. A huge difficulty in
exploring APIs tautomerism originates from substantial environmental sensitivity of tautomeric
equilibrium which may change unexpectedly in response to mutable external conditions, such as
temperature, pH, solvent or mechanical stress. The concept of real time monitoring of reaction
progress by means of broadband dielectric spectroscopy (BDS) gained recognition in the previous
studies of our group.1 To realize this task it is required that the progress of tautomerization is
associated with changes in viscosity and/or variations of the resultant dipole moment of a sample.
So far our results have shown that the presence of distinct tautomeric forms may positively impact
the stability of amorphous products (e.g. glibenclamide, etoricoxib).1,2 In this presentation we
will discuss the possibility of tautomeric conversion in popular anti-androgen drug bicalutamide
(BIC). We found that thermal processing applied during glass preparation via vitrification method
results in the presence of amide and imidic-acid forms in glassy BIC. Further heating leads to re-
equilibration of supercooled BIC manifested by the growth of viscosity and effective dipole
moment. Based on the value of activation energy determined in theoretical and experimental BDS
studies we recognized that the observed time evolution of dielectric parameters likely reflects the
increasing amount of more stable amide tautomer.
REFERENCES
1. Wojnarowska, Z., Wlodarczyk, P., Kaminski, K., Grzybowska, K., Hawelek, L., Paluch, M., J Chem Phys.
133 (9), 1-9 (2010).
2. Rams-Baron, M., Wojnarowska, Z., Grzybowska, K., Dulski, M., Knapik, J., Jurkiewicz, K., Smolka, W.,
Sawicki, W., Ratuszna, A., Paluch, M., Mol. Pharm., 12(10), 3628-3638 (2015).
ORAL CONTRIBUTIONS AM-Pharm-7
Invited Talk
Disorder in Pharmaceuticals: Insights from Dielectric
Spectroscopies and MD Simulations
M.T. Viciosa,a H.P. Diogo,
b F. Affouard,
c and N.T. Correia
c
aCQFM − Centro de Química-Física Molecular and IN − Institute of Nanoscience and
Nanotechnology;
bCQE – Centro de Quimica Estrutural, Instituto Superior Técnico, Universidade de Lisboa,
Avenida Rovisco Pais, 1049-001 Lisboa, Portugal.
cUniv. Lille, CNRS, UMR 8207, UMET, Unité Matériaux et Transformations, F59 000 Lille,
France.
The development of active substances in disordered forms (metastable disordered crystal,
liquid crystal, semi-crystalline or amorphous solid…) has motivated a strong interest within
the pharmaceutical formulation in order to improve biopharmaceutical properties. Due to the
higher free energy, disordered forms often show physicochemical properties that may
improve solubility and dissolution capabilities relatively to the completely ordered crystalline
counterpart. However, such disordered forms can be physically and/or chemically metastable
or unstable which is a significant drawback from a pharmaceutical perspective.
In the present talk, we will discuss in detail some aspects regarding molecular dynamics and
phase transformations as probed by dielectric techniques (Dielectric Relaxation Spectroscopy
and Thermally Stimulated Depolarization Currents) and MD simulations, taking as model
drug simvastatin, a cholesterol-lowering agent commonly used to treat hypercholesterolemia.
Specific features of phase diagram and stability of this substance are shown to be the result of
an original interplay between structure, interactions and dynamics of molecules.
ACKNOWLEDGEMENTS
M.T. Viciosa thanks the Fundação para a Ciência e Tecnologia (FCT, Portugal) for the post-
doc grant SFRH/BPD/110151/2015. This work has received funding from the Interreg 2 Seas
programme 2014-2020 co-funded by the European Regional Development Fund under
IMODE project.
AM-Pharm-8 ORAL CONTRIBUTIONS
Invited Talk
Physical instability – the real and complex problem of
amorphous pharmaceuticals
J. Knapik-Kowalczuk1,2*
, Z. Wojnarowska1,2
, K. Jurkiewicz1,2
, K. L. Ngai4,
M. Paluch1,2
1Institute of Physics, University of Silesia, ul. Uniwersytecka 4, 40-007 Katowice, Poland
2SMCEBI, ul. 75 Pułku Piechoty 1a, 41-500 Chorzów, Poland
3Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Poznan University of
Medical Sciences, Grunwaldzka 6, 60-780 Poznan, Poland
4CNR-IPCF, Dipartimento di Fisica, Largo Bruno Pontecorvo 3, I-56127, Pisa, Italy
Poor solubility of drugs and drug’s candidates is one of the major problems limiting
their bioavailability. The scale of this problem is quite enormous since it is estimated that
nearly 40% of drugs on the market and more than 80% of future drug candidates are weakly
soluble in water1. There are numerous strategies proposed for the enhancement of the
solubility of poorly soluble drugs. One of them is producing the amorphous drugs2. However,
this approach has one potential problem: amorphous drugs are physically unstable. It means
that during storage or manufacturing amorphous pharmaceuticals might revert to their
starting, crystalline, form, and simultaneously will lose their desirable properties3. For this
reason, in recent years, many efforts have been made to recognize relevant factors controlling
the physical stability and, consequently, to elaborate efficient methods for prevention of the
amorphous drugs recrystallization4. In this presentation I will focus on the general problem of
physical stability of amorphous active substances both at standard storage and manufacturing
conditions. A particular emphasis will be put on the monitoring the physical stability of
amorphous active substances at conditions imitating the manufacturing process, by using the
high pressure dielectric spectroscopy technique.
REFERENCES
1. Craye G., Löbmann K., Grohganz H., Rades T., Laitinen R., Characterization of Amorphous and Co-
Amorphous Simvastatin Formulations Prepared by Spray Drying. Molecules 2015, 20, 21532–21548.
2. Williams H. D., Trevaskis N. L., Charman S. A., Shanker R. M., Charman W. N., Pouton C. W., Porter C. J.
H., Strategies to Address Low Drug Solubility in Discovery and Development. Pharmacol Rev 2013, 5,
315–499.
3. Grzybowska K., Paluch M., Wlodarczyk P., Grzybowski A., Kaminski K., Hawelek L., Zakowiecki D.,
Kasprzycka A., Jankowska-Sumara I., Enhancement of amorphous celecoxib stability by mixing it with
octaacetylmaltose: the molecular dynamics study. Mol. Pharmaceutics 2012, 9 (4), 894−904.
4. Knapik J., Wojnarowska Z., Grzybowska K., Jurkiewicz K., Tajber L., Paluch M., Molecular Dynamics and
Physical Stability of Coamorphous Ezetimib and Indapamide Mixtures. Mol. Pharmaceutics 2015, 12,
3610−9.
ORAL CONTRIBUTIONS AM-Pharm-9
Invited Talk
Relaxation dynamics in amorphous pharmaceuticals:
Insights from the classic glass formers
M. Shahin Thayyil1*, S. Capaccioli
2, U. Sailaja
3, M. Sahra
1, Safna Hussan
1,
K.L. Ngai2
1- Department of Physics, University of Calicut, Kerala, India;
2-Departimento di Fisica, Universita di Pisa & CNR-IPCF, Largo B. Pontecorvo 3, Pisa, Italy;
3- Department of Physics, MES Keveeyam College, Valanchery, Malappuram, Kerala, India.
Solubility and permeability are two critical factors governing the bioavailability of orally
administered active pharmaceutical ingredients (APIs). When an API is poorly water soluble while
having good permeability, the amorphous route paves a promising route to enhance the bioavailability
[1]. Further, most of the upcoming lifesaving API formulations are in solid form with low aqueous
solubility at ambient conditions. Ensuring the stability of the amorphous phase to a long time of 2-3
years as demanded by the pharmaceutical industry is another Herculean task. Crystallization during
the storage poses a serious limitation in inducting this technology to the industry. Classically, the
crystallization is characterized by the long range ordering of molecules and hence the molecular
relaxation dynamics related with intermolecular degrees of freedom are relevant to finding ways to
enhance stability of the glassy phase.
The effort is facilitated by recent experimental studies and theoretical considerations on classic
glass-formers of rigid, flexible systems with systematic change of shape, structure and glass transition
temperature and even by elevating the pressure in few systems to see whether the Johari-Goldstein β-
relaxation [2-3] is universal feature in these systems by having strong correlation to their structural
relaxation. Investigations were further carried out on nine APIs having different physical and chemical
properties by broadband dielectric spectroscopy (10-2–107 Hz) to understand the factors governing the
stability of amorphous pharmaceuticals. Together with the new data, other pharmaceutical data from
the literature, data of the classic glass formers investigated & collected from the previous studies, we
infer that the Johari-Goldstein β-relaxation is governing a decisive role in the crystallization dynamics
of amorphous drugs and by suppressing the former can in effect enhance the stability of the
amorphous phase to have longer shelf life [4-5].
REFERENCES
1. J. A. Baird, B. V. Eerdenbrugh, L. S.Taylor, J. Pharm. Sci. 99, 3787 (2010)
2. K. L. Ngai, M. Paluch, J. Chem. Phys. 120, 857 (2004)
3. S. Capaccioli, M. Shahin Thayyil, K. L. Ngai, J. Chem. Phys. B 112, 16035 ( 2008)
4. M. Paluch, J. Knapik, Z. Wojnarowska, A. Grzybowski, and K. L. Ngai, Phys. Rev. Lett. 116, 025702
(2016)
5. U. Sailaja, M. Shahin Thayyil, N.S. Krishnakumar, G. Govindaraj, K. L. Ngai, Eur. J. Pharm. Sci. 99, 147
(2017)
AM-Pharm-10 ORAL CONTRIBUTIONS
Oral
Molecular Dynamics of double active pharmaceutical
ingredient- benzalkonium ibuprofenate studied by
Broadband Dielectric Spectroscopy
K.P. Safna Hussan a, M. Shahin Thayyil
a, S.K. Deshpande
b, T.V. Jinitha
c,
Vijisha K. Rajan c, K.L. Ngai
d
aDepartment of Physics, University of Calicut, Malappuram 673635, Kerala, India
bUGC-DAE Consortium for Scientific Research, Mumbai Centre, , BARC, Mumbai, India
cDepartment of Chemistry, University of Calicut, Malappuram 673635, Kerala, India
dDipartimento di Fisica, Università di Pisa, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
Double active pharmaceutical ingredient (d-API) is one of the most interesting and not well
described classes of ionic liquids (IL).since it was proven that medicine in the IL form reveal
better solubility and consequently bioavailability in contrast to their basic crystalline form.
They are formed by stoichiometric metathesis reaction of pharmaceutically active anion with
pharmaceutically active cation. D-API is convenient compound to investigate the glass
transition problem since it does not manifest crystallization during cooling. Here molecular
dynamics of a Double active pharmaceutical ingredient benzalkonium ibuprofenate with anti-
bacterial and anti-inflammatory roles, which offers high solubility, bio-availability, and
biological activity were investigated by means of broadband dielectric spectroscopy. It
showed a single resolved peak in the electric modulus formalism and doesn’t show any
crystallization tendency during cooling as well as heating. The temperature dependence of the
conductivity relaxation has been fitted by single Vogel–Fulcher–Tamman (VFT) equation.
The glass transition temperature Tg = 194.14 K and fragility index m = 68.58 were estimated
and compared with other members of the profen's family by Vogel–Fulcher–Tamman (VFT)
equation. This study revealed that the synthesized d-API BaIb is an excellent glass former.
REFERENCES
1. Safna Hussan, K.P., Shahin Thayyil, M., Deshpande, S.K., Jinitha, T.V., Vijisha K. Rajan, Ngai, K.L.,
Synthesis and molecular dynamics of double active pharmaceutical ingredient-benzalkonium ibuprofenate,
J MoliLiq, 223 1333–1339, (2016).
2. Hodge, I. M.; Ngai, K. L.; Moynihan, C. T. Comments on the Electric Modulus Function. J. Non. Cryst.
Solids, 351 (2), 104–115 (2005).
3. Mano, J. F.; Pereira, E. Data Analysis with the Vogel-Fulcher-Tammann-Hesse Equation. J. Phys. Chem. A,
108 (49), 10824–10833 (2004).
4. Sailaja, U.; Shahin Thayyil, M.; Krishna Kumar, N. S.; Govindaraj, G. Molecular Dynamics in Liquid and
Glassy States of Non-Steroidal Anti-Inflammatory Drug: Ketoprofen. Eur. J. Pharm. Sci, 49 (2) (2013).
ORAL CONTRIBUTIONS AM-Pharm-11
Invited Talk
Toward General Understanding and Strategic Regulation of
Isothermal Crystallization of Pharmaceutical Glasses
Kohsaku Kawakami
World Premier International Research Center for Materials Nanoarchitectonics (WPI-
MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044,
Japan
Use of glassy state offers great benefit for pharmaceutical products, because its high energy
state leads to improvement in the dissolution behavior of drug molecules. However,
maintenance of the glassy state during storage can be a great challenge sometimes, which may
become a reason to give up employing the glassy state for development. We have investigated
isothermal crystallization behavior of nine pharmaceutical glasses at various temperatures to
find that initiation time for the crystallization can be explained in a general manner1,2,3
. In this
conclusion, initiation time of the crystallization was simply expressed as a function of a ratio
between glass transition temperature (Tg) and storage temperature for most compounds. Other
compounds exhibited longer initiation time, for which molecular interaction also needs to be
considered. Crystallization of the latter compounds was sensitive to surface area, and the
crystallization behavior was similar with the temperature-controlled compounds when the
surface area was sufficiently large2. Since crystallization of these compounds are significantly
influenced by the molecular interaction, crystallization can be retarded by manipulating
molecular interaction. We have applied sub-Tg annealing to ritonavir glass to retard its
isothermal crystallization, which was understood by rearrangement of hydrogen-bond
structure during the annealing4. This “sub-Tg annealing” strategy may be used for
stabilization of the pharmaceutical glasses.
REFERENCES
1. K. Kawakami, T. Harada, K. Miura, Y. Yoshihashi, E. Yonemochi, K. Terada, H. Moriyama, Relationship
between Crystallization Tendencies during Cooling from Melt and Isothermal Storage: Toward a General
Understanding of Physical Stability of Pharmaceutical Glasses, Mol. Pharmaceutics 11, 1835-1843 (2014).
2. K. Kawakami, Surface Effects on the Crystallization of Ritonavir Glass, J. Pharm. Sci. 104, 276-279 (2015).
3. K. Kawakami, C. Ohba, Crystallization of Probucol from Solution and the Glassy State, Int. J. Pharm. 517,
322-328 (2017).
4. S. Tominaka, K. Kawakami, M. Fukushima, A. Miyazaki, Physical Stabilization of Pharmaceutical Glasses
Based on Hydrogen Bond Reorganization under Sub-Tg Temperature, Mol. Pharmaceutics 14, 264-273
(2017).
AM-Pharm-12 ORAL CONTRIBUTIONS
Invited Talk
Mechanisms of protein denaturation and stabilization
analyzed in-situ during the freeze-drying process by micro-
Raman spectroscopy
Tatiana STARCIUC, Yannick GUINET, Alain HEDOUX
Unité Matériaux Et Transformations, UMR CNRS 8207, Université de Lille 1, 59655
Villeneuve d’Ascq Cédex, France
Nowadays, more and more biological drugs, especially proteins, are discovered being labile in solution
and requiring storage in the solid state. Freeze drying (FD) is widely used in Pharmaceutical industry
in order to improve the long-term stability of proteins in the solid state. FD is a process of choice and
widely recognized as a soft method for drying proteins with a low degree of degradation. However,
during the freeze-drying cycle, proteins are exposed to a series of stresses (changes in temperature,
pressure, dehydration, pH and concentration). In this context, different excipients (sugars, polyols, etc)
are added in drug formulation for the protection of the protein structure during FD cycles, having also
the role to stabilize the protein for a long-term storage. All of these formulations are often used
empirically without precise knowledge about the origin and the nature of denaturation.
Disaccharides, especially trehalose are commonly recognized as efficient bioprotective agents which
can be used for protein stabilization against various kinds of stress. However, the mechanisms by
which sugars stabilize proteins during FD are still unclear, mainly because analyzes of protein stability
are usually performed on the freeze-dried product, i.e. at the end of the FD process.
We have recently developed micro-Raman investigations on protein formulations within pressure-
temperature device mimicking FD cycles, which enable the simultaneous monitoring of the FD
process and the protein stability. In-situ Raman measurements have revealed the main source and the
nature of protein degradation. Furthermore, Raman imaging also performed in-situ during the FD
process provided quantitative information about the degree of denaturation in relation with the
preferential interactions between protein, water and co-solvent. These experimental developments and
their contribution to deciphering the mechanisms of protein stabilization by trehalose will be
presented. Additionally, a special attention will be given on the modification of the bioprotective
properties of trehalose during the FD process by a small amount of glycerol. Although it is well known
that glycerol enhances the bioprotective efficiency of trehalose, it will be shown that glycerol has
different influence on the amorphous matrix embedding the protein (plasticizing – antiplasticizing
effect), at the primary and secondary drying stages of the FD process. Physical properties of the
freeze-dried product (RH, relaxational motions in the amorphous matrix) will be discussed in relation
with the protein stability during long-term storage.
ORAL CONTRIBUTIONS AM-Pharm-13
Invited Talk
Ciprofloxacin – a molecule with two faces and ability to
form amorphous polymeric drug salts
Tajber Lidia1, Hanah Mesallati
1, Naila Mugheirbi
2, Anita Umerska
3,
Krzysztof Paluch4
1. Synthesis and Solid State Pharmaceutical Centre, School of Pharmacy and Pharmaceutical Sciences,
Trinity College Dublin, College Green, Dublin 2, Ireland.
2. Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West
Lafayette, Indiana, 47907, USA.
3. Inserm U1066 (Micro et Nanomédecines biomimétiques), Angers, France.
4. Bradford School of Pharmacy, University of Bradford, West Yorkshire, BD7 1DP, UK.
Ciprofloxacin (1-cyclopropyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydroquinoline-3-carboxylic acid,
CIP) is a second generation fluoroquinolone with a wide spectrum of antibiotic activity (1). CIP can exist in
two different forms: the zwitterion and the unionised form. In solution, the carboxylic acid and piperazine
group of CIP can ionise depending on pH of the surrounding media. However, in the neutral pH range CIP
is zwitterionic and has an overall neutral charge, making it practically insoluble in aqueous media. The
poor solubility of CIP is furthermore coupled with poor permeability, thus amorphisation was investigated
as a means of improving the inadequate pharmaceutical properties of CIP.
This presentation reveals the solid state transformations of CIP, with a particular emphasis on the ionisation
state (zwitterionic or unionised) of this molecule (2). Ball milling, cryomilling, and spray drying were used
in this study to prepare partially and fully amorphous CIP. CIP proved to be very difficult to amorphise,
with only spray drying in pure water resulting in a fully amorphous product. It was shown that while most
processing methods resulted in the more stable zwitterionic form of the drug, spray drying in an
ethanol/water mixture produced the unionised form. The zwitterion was found to convert to the unionised
form upon heating to its melting point, and the reverse transformation occurred when unionised CIP was
exposed to high humidity. CIP was found to amorphise more readily when co-processed with acidic
pharmaceutical polymers forming amorphous polymeric drug salts (ASDs). Unlike a number of other
solubility enhancing formulations, the ASDs did not decrease the permeability of the drug. Similarly, no
decrease in antibiotic efficacy was observed, and significant improvements in the minimum inhibitory
concentration and minimum bactericidal concentration of CIP were obtained with ASDs containing
HPMCAS-LG and HPMCAS-MG. Therefore, ASDs may be a viable alternative for formulating CIP with
improved solubility, bioavailability and antimicrobial activity.
REFERENCES
1. Sanders, C.C., Sanders, W.E., Goering, R.V., Am. J. Med. 82, 2– 11 (1987).
2. Mesallati, H, Mugheirbi, N.A., Tajber, L. Cryst. Growth Des. 16, 6574–6585 (2016).
AM-Pharm-14 ORAL CONTRIBUTIONS
Oral
Flash DSC study of the melting behavior of Cytosine
Abdelaziz, A.1,2
, Zaitsau, D.H.2,3
; Mukhametzyanov, T.4 Verevkin, S.P.
2,3,
Schick, C.1,2,4
1 University of Rostock, Institute of Physics, Albert-Einstein-Str. 23-24, 18051 Rostock,
Germany
2 University of Rostock, Faculty of Interdisciplinary Research, Competence Centre CALOR,
Albert-Einstein-Str. 25, 18051 Rostock, Germany
3 University of Rostock, Institute of Chemistry, Dr-Lorenz-Weg 1, 18051 Rostock, Germany
4 Kazan Federal University, 18 Kremlyovskaya Street, Kazan 420008, Russian Federation
We report, for the first time, the melting behavior of cytosine, one of the nucleobases,
building blocks of DNA and RNA sequences.
Cytosine is known to decompose during the melting process, this makes the application of
conventional calorimetric methods meaningless for investigation of the melting of this
thermally instable biomolecule.
With the help of Mettler Toledo flash DSC1, the sample of solid cytosine was heated with a
scanning rate of 6000 K•s-1 above the proposed temperature of fusion. No obvious evidence
of cytosine decomposition was observed. Upon quenching, with high cooling rate a partial
verification was observed.
Several experiments were carried out in order to get reliable values of fusion temperature,
fusion enthalpy, as well as the glass transition temperature and the specific heat capacity of
liquid cytosine - reported for the first time.
ORAL CONTRIBUTIONS Boson-P-1
Invited talk
Transport of heat and sound in disordered solids
Stefano Mossa1, Hideyuki Mizuno
2, and Jean-Louis Barrat
3
1 Univ. Grenoble Alpes, CNRS, CEA, INAC/SYMMES, F-38000 Grenoble, France
2 Graduate School of Arts and Sciences, The University of Tokyo, Tokyo 153-8902, Japan
3 Univ. Grenoble Alpes, CNRS, LiPhy, F-38000 Grenoble, France
In a recent series of papers1-3
we have described extensive numerical work focusing on the concept of
elastic heterogeneity in disordered solids. The idea is quite simple: glasses and disordered (or even
very complex) crystals show inhomogeneous mechanical response at the nano-scale, which does not
conform to the macroscopic limit predictions. This property can be demonstrated to strongly influence
vibrational and thermal properties, and could ultimately lie at the bottom of the puzzling anomalous
features of glassy phases, including boson peak, vibrational localization, and temperature dependence
of thermal conductivity.
In order to address all the above issues in great details and in a single framework, we have considered
a toy model constituted by a binary mixture of soft spheres, in fixed high-T/low-ρ conditions. The
interesting feature of such a system is that one can stabilize different solid states of matter by simply
tuning continuously the strength of the particles size disorder. Consequently, the phase diagram
generated by Molecular Dynamics simulations encompasses the perfect crystalline state with a
spatially homogeneous elastic moduli distribution, multiple defective phases with increasing moduli
heterogeneities, and eventually a series of amorphous states. We have monitored independently
mechanical response, collective excitations, and heat transfers across these changes, and have
established clear correlations among the heterogeneous local mechanical response, the nature of the
vibrational states, and the variation of thermal conductivity. In the talk I will focus, in particular, on
this latter. If time will allow, I will also show that, wisely localizing heterogeneities at interfaces, one
can devise completely ordered materials (super-lattices) with values of thermal conductivity lower
than those shown by their amorphous counterpart with exactly the same chemical composition4.
REFERENCES
1. H. Mizuno, S. Mossa, and J.-L. Barrat, Relation of vibrational excitations and thermal conductivity to
elastic heterogeneities in disordered solids, Phys. Rev. B 94, 144303 (2016) [10.1103/PhysRevB.94.144303]
2. H. Mizuno, S. Mossa, and J.-L. Barrat, Acoustic excitations and elastic heterogeneities in disordered
solids, Proc. Natl. Acad. Sci. USA 111, 11949 (2014) [10.1073/pnas.1409490111]
3. H. Mizuno, S. Mossa, and J.-L. Barrat, Elastic heterogeneity, vibrational states, and thermal conductivity
across an amorphisation transition, EPL 104, 56001 (2013) [10.1209/0295-5075/104/56001]
4. H. Mizuno, S. Mossa, and J.-L. Barrat, Beating the amorphous limit in thermal conductivity by
superlattices design, Sci. Rep. 5, 14116 (2015) [10.1038/srep14116]
Boson-P-2 ORAL CONTRIBUTIONS
Invited Talk
Microscopic origin of the boson peak and its link with the
dielectric response of glasses
Alessio Zaccone
Department of Chemical Engineering and Biotechnology, and Cavendish Laboratory,
University of Cambridge, CB3 0AS Cambridge, U.K.
The boson peak in glasses manifests itself as an excess of modes above the Debye law. It has
been the object of several theoretical treatments, attempting to identify the structural and
dynamical features responsible for its appearance in a variety of materials, such as molecular,
oxide, polymer and metallic glasses, and crystals as well. A consensus has emerged recently
about the close link between boson peak and a crossover from ballistic phonons to quasi-
localized diffusive-like excitations akin to a Ioffe-Refel crossover. In this picture, disorder is
supposed to play a major role by promoting scattering and localization phenomena. Yet, the
precise microscopic nature of “disorder” has remained elusive. We have recently shown [1],
on the example of model random network glasses and defective crystals, that the type of
disorder responsible for the boson peak has little or nothing to do with the standard bond-
orientational disorder and its well known order parameter, whereas it correlates strongly with
the local degree of centrosymmetry. The latter is the central feature which promotes the
scattering of phonons, and is the same which governs nonaffine displacements in the elastic
response [2], thus establishing a direct link between boson peak and nonaffine deformations.
This picture also explains the experimental observation of a strong boson peak in alpha-quartz
[3], which is a non-centrosymmetric material. Finally, we show how a direct link can be built
between the vibrational density of states (and the boson peak) and the dielectric alpha-
relaxation of glasses on the example of glycerol. The asymmetric alpha-wing in the dielectric
loss modulus is strongly controlled by the boson peak in the density of states, in contrast with
the widespread view that the boson peak should play a role a much higher field frequencies.
REFERENCES
1. Milkus, R., Zaccone, A., Local inversion-symmetry breaking controls the boson peak in glasses and
crystals, Physical Review B 93, 094204 (2016).
2. Zaccone, A., Scossa-Romano, E., Approximate analytical description of the nonaffine response of
amorphous solids, Physical Review B 83, 184205 (2015).
3. Chumakov, A. I., et al. Role of Disorder in the Thermodynamics and Atomic Dynamics of Glasses, Physical
Review Letters 112, 025502 (2014).
4. Cui, B., Milkus, R., Zaccone, A., Direct link between boson-peak modes and dielectric α-relaxation in
glasses, Physical Review E 95, 022603 (2017).
ORAL CONTRIBUTIONS Boson-P-3
Invited Talk
Effects of coordination and pressure on sound attenuation,
boson peak and elasticity in amorphous solids
Eric DeGiuli,a Gustavo During,b Edan Lerner,c and Matthieu Wyart
d
a LPT, Ecole Normale Superiore, 24 Rue Lhomand, 75231 Paris, France
b Pontificia Universidad Catolica de Chile, Casilla 306, Santiago 22, Chile
c Institute of Physics, University of Amsterdam, 1098 XH Amsterdam, Netherlands
d Institute of Physics, Ecole Polytechnique Federale de Lausanne, CH-1015, Switzerland
Connectedness and applied stress strongly affect elasticity in solids. In various amorphous
materials, mechanical stability can be lost either by reducing connectedness or by increasing
pressure. We present an effective medium theory of elasticity that extends previous
approaches by incorporating the effect of compression, of amplitude e, allowing one to
describe quantitative features of sound propagation, transport, the boson peak, and elastic
moduli near the elastic instability occurring at a compression ec. The theory disentangles
several frequencies characterizing the vibrational spectrum: the onset frequency ω0 where
strongly-scattered modes appear in the vibrational spectrum, the pressure-independent
frequency ω* where the density of states displays a plateau, the boson peak frequency ωBP,
and the Ioffe–Regel frequency ωIR where scattering length and wavelength become equal. We
predict that sound attenuation crosses over from ω4 to ω2 behaviour at ω0, consistent with
observations in glasses. We predict that a frequency-dependent length scale ls(ω) and speed of
sound ν(ω) characterize vibrational modes, and could be extracted from scattering data. One
key result is the prediction of a flat diffusivity above ω0, in agreement with previously
unexplained observations. We find that the shear modulus does not vanish at the elastic
instability, but drops by a factor of 2. We check our predictions in packings of soft particles
and study the case of covalent networks and silica, for which we predict ωIR ≈ ωBP. Overall,
our approach unifies sound attenuation, transport and length scales entering elasticity in a
single framework where disorder is not the main parameter controlling the boson peak, in
agreement with observations. This framework leads to a phase diagram where various glasses
can be placed, connecting microscopic structure to vibrational properties.
Boson-P-4 ORAL CONTRIBUTIONS
Invited Talk
Ioffe-Regel Localization of Acoustic Excitations in Liquids
Yang Zhang
University of Illinois at Urbana-Champaign, Urbana, IL, USA
Long wavelength longitudinal phonons can propagate in liquids, but whether transverse
phonons exist in liquids has been long debated. The classic hydrodynamic theory refutes the
existence of transverse phonons in liquids because the transverse current fluctuation is not
directly coupled with the density fluctuation and the Brillouin zone is not well-defined.
However, such arguments utterly fail to describe the non-linear viscoelastic response of
liquids. Herein, I will show coherent inelastic neutron scattering measurements of the phonon
dispersion relation of metallic liquids and glasses. Two phonon branches, the longitudinal and
the transverse, are clearly identified. These experimental observations are also confirmed in
both density and current correlation functions obtained from MD simulations using EAM
potential. Furthermore, we found that the Ioffe-Regel delocalization point of these phonon
modes coincides with the onset of non-Arrhenius transport, dynamic heterogeneity,
landscape-influenced regime, and the breakdown of Stokes-Einstein relation. Therefore, it is
tempting to interpret the phonon delocalization is the microscopic driving force of the
strongly-correlated behavior of liquids. We have also developed a generalized hydrodynamic
theory to account for the observed phenomenon.
REFERENCES
1. A. Jaiswal, T. Egami, K. F. Kelton, K. S. Schweizer, Y. Zhang*, “Correlation between fragility and the
Arrhenius crossover phenomenon in metallic, molecular, and network liquids”, Phys. Rev. Lett. 117,
205701 (2016)
2. A. Jaiswal, S. O’Keefe, R. Mills, A. Podlesynak, G. Ehlers, W. Dmowski, K. Lokshin, T. Egami, Y.
Zhang*, “Onset of cooperative dynamics in an equilibrium glass-forming metallic liquid”, J. Phys. Chem. B
120(6), 1142 (2016)
3. A. Jaiswal, Y. Zhang*, “Robustness of dynamical cluster analysis in a glass-forming metallic liquid using
an unsupervised machine learning algorithm”, MRS Adv. 1(26), 1929 (2016)
4. A. Jaiswal, A. Podlesynak, G. Ehlers, R. Mills, S. O’Keefe, J. Stevick, J. Kempton, G. Jelbert, W. Dmowski,
K. Lokshin, T. Egami, Y. Zhang*, “Coincidence of collective relaxation anomaly and specific heat peak in
a bulk metallic glass-forming liquid”, Phys. Rev. B 92, 024202 (2015)
5. A. Jaiswal, T. Egami, Y. Zhang*, “Atomic-scale dynamics of a model glass-forming metallic liquid:
dynamical crossover, dynamical decoupling, and dynamical clustering”, Phys. Rev. B 91, 134204 (2015)
ORAL CONTRIBUTIONS Boson-P-5
Invited Talk
Terahertz vibrations of oxide, metallic and organic glasses
Giacomo Baldi
Department of Physics, Trento University, Trento, Italy.
I will report on experiments performed in recent years by means of high resolution inelastic x-
rays scattering on a series of glasses of different structure and composition. We have observed
that the spectrum of glass vibrations at terahertz frequency is similar to that of an assembly of
polycrystalline aggregates of nanometer or sub-nanometer size, a length comparable to the
extent of the medium range order of the glass [1]. The elastic modulus fluctuations occurring
on this length scale are responsible for the strong damping of the sound waves [2,3] (Rayleigh
scattering) and for the appearance of a plateau in the thermal conductivity at low
temperatures. The vibrational dynamics of the glass is characterized by dispersion curves
similar to those of a polycrystal, and the mode dispersion persists in the liquid phase [4,5].
REFERENCES
1. Baldi, G. et al., Emergence of crystal-like atomic dynamics in glasses at the nanometer scale., Phys. Rev.
Lett. 110, 185503 (2013).
2. Baldi, G. et al., Anharmonic Damping of Terahertz Acoustic Waves in a Network Glass and Its Effect on
the Density of Vibrational States, Phys. Rev. Lett. 112, 125502 (2014).
3. Baldi, G. et al., On the nontrivial wave-vector dependence of the elastic modulus of glasses, Phys. Rev. B
93, 144204 (2016).
4. Benassi, P. et al., Collective excitations in liquid and glassy 3-methylpentane, Phys. Rev. B 92, 104203
(2015).
5. Baldi, G. et al., Damping of vibrational excitations in glasses at terahertz frequency: the case of 3-
Methylpentane, submitted to Phys. Rev. B.
Boson-P-6 ORAL CONTRIBUTIONS
Invited Talk
Vibrational excitations in the continuum limit of
amorphous solids
Hideyuki Mizuno, Hayato Shiba, Atsushi Ikeda
Graduate School of Arts and Sciences, The University of Tokyo, Tokyo 153-8902, Japan,
Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
Why low-ω-vibrational and low-T-thermal properties of amorphous solids are markedly
different from the crystalline counterparts is a long-standing mystery in condensed matter
physics. Crystals follow the universal laws which are controlled by phonon. Experimental
observations of the vibrational density of states g(ω) ~ ω2, heat capacity C ~ T
3, and the
thermal conductivity κ ~ T3 are rationalized by the Debye theory and the phonon-gas theory
based on the phonon. Amorphous solids are characterized as well by the universal laws that
are, however, anomalous with respect to the crystalline counterparts. Much attention has been
paid to the boson peak (BP): The heat capacity C is larger than the crystalline value at T ≈
10[K], which directly reflects the excess vibrational modes around ωBP ≈ 1[THz].
Here, we would remark that even at much lower T ≤ 1[K], thermal properties are already
anomalous, e.g., the thermal conductivity increases as κ ~ T2, instead of κ ~ T
3. This indicates
that the vibrational modes are not rationalized by the phonon even at very low ω ≈ 0.1[THz],
one order of magnitude lower than ωBP. This behavior is highly counter-intuitive because any
solid matter, not only crystalline but also amorphous, is expected to behave as a homogeneous
elastic medium in the continuum limit, and its vibrational modes are expected to converge to
the phonons in the low-ω regime.
In this work, we attempt to directly observe the extremely low-ω modes even far below ωBP,
by numerical simulations. We perform large-scale, vibrational mode analysis on a simple
model of amorphous solids, composed of up to millions of particles (N ~ 106). We indeed see
the phonon in the model amorphous solid, however at the same time, we also observe the
other, quasi-localized mode. In this talk, we will try to give an answer to the question: How
and to what do the vibrational modes converge in the continuum limit (the low-ω limit) ?
REFERENCES
1. H.Mizuno, H.Shiba, A.Ikeda, arXiv:1703.10004 (2017).
ORAL CONTRIBUTIONS Boson-P-7
Invited Talk
High-frequency dynamics of liquids: direct links between
dynamical, thermodynamic and structural properties from
MD modelling results
Ling Wang & Dr. Kostya Trachenko
Queen Mary University of London, Mile End Road, London E1 4NS
We develop an approach to liquid thermodynamics based on collective modes including high-
frequency transverse modes [1]. We perform extensive molecular dynamics simulations of
noble, molecular and metallic liquids and provide the direct evidence that liquid energy and
specific heat are well-described by the evolution of high-frequency transverse modes
propagating above the Frenkel (hopping) frequency. The agreement between predicted and
calculated thermodynamic properties is seen in the notably wide range of temperature
spanning tens of thousands of Kelvin. The range includes both subcritical liquids and
supercritical liquids [2]. We discuss interrelationships between structure, dynamics and
thermodynamics of liquids and supercritical fluids and the structural crossover at the Frenkel
line [1].
REFERENCES
1. K. Trachenko and V. V. Brazhkin, Collective modes and thermodynamics of liquid state, Reports on
Progress in Physics. 79, 016502 (2016)
2. L. Wang, C. Yang, M. T. Dove, Yu. D. Fomin, V. V. Brazhkin and K. Trachenko, Direct links between
dynamical, thermodynamic, and structural properties of liquids: Modelling results, Physical Review E. 95,
032116 (2017)
Boson-P-8 ORAL CONTRIBUTIONS
Invited Talk
Correlation between local structure and boson peak in
glasses
G. D'Angelo
Dipartimento di Matematica, Informatica, Fisica e Scienze della Terra, Università degli Studi
di Messina, Messina, Italy
Understanding the relationship between atomic scale arrangement, vibrational dynamics and
thermal properties is a crucial point in the study of glasses for predicting their properties and
enabling the design for their application in areas not previously considered.
Here I show the results of a detailed investigation of the intermediate range structure on
several oxide glasses. I used a void model to explain the compositional and pressure
dependence of the first sharp diffraction peak in glasses. According to these observations, I
conclude that the medium range order in glasses arises from the periodicity of the void
boundaries over a random network of basic structural units.
Furthermore a correlation is found between the low energy excess of vibrational states (the
Boson Peak), the vibrational frequencies of random puckered rings and the size of voids on
the nanometer length scale.
This approach has been successfully applied to several inorganic and organic compounds,
proving that this view holds for a wide variety of systems sharing ring-based structures.
ORAL CONTRIBUTIONS Boson-P-9
Invited Talk
A 100 Myears landscape exploration using a geologically
hyperaged glass
T. Scopigno
Dipartimento di Fisica, Universita’ “Sapienza” Roma - I
The way structure and dynamics of amorphous materials relate to their thermodynamic
metastability is one of the current challenges for the glass transition understanding. From the
experimental point of view, one of the major hurdles is the limited stability range
conventionally accessible on the laboratory timescale. Fossil amber offers the unique
opportunity of investigating an amorphous material which has been exploring its energy
landscape for more than 110 Myears of natural ageing. By applying different x-ray scattering
methods to fossil amber before and after rejuvenating it, we identify a link between the
potential energy landscape and the structural and vibrational properties of glasses.
Specifically, we find that hyperaging induces a depletion of the vibrational density of states in
the THz region, also ruling the sound dispersion and attenuation properties of the
corresponding acoustic waves. Critically, this is accompanied by homogeneous densification,
peculiar of natural stabilization and different in nature from that caused by hydrostatic
compression. Our results can be rationalized within the fluctuating elasticity theory, revealing
that upon approaching the bottom of the potential energy landscape the elastic matrix
becomes increasingly less disordered, though retaining the characteristic vibrational
anomalies of glasses.
Boson-P-10 ORAL CONTRIBUTIONS
Oral
Glassy anomalies and boson peak in low-dimensional molecular
crystals
A.I. Krivchikov1, Y. V. Horbatenko
1, O.A. Korolyuk
1, O.O. Romantsova
1,
D. Szewczyk2, A. Jezowski
2, J. Ll. Tamarit
3, M.A. Ramos
4.
1 B. Verkin Institute for Low Temperature Physics and Engineering of NAS Ukraine, 47
Science Avenue, Kharkov 61103, Ukraine
2 Institute for Low Temperature and Structure Research, Polish Academy of Sciences Okólna
2, 50-422 Wrocław, Poland
3 Grup de Caracterizació de Materials, Departament de Fisica, EEBE and Barcelona Research
Center in Multiscale Science and Engineering, Universitat Politècnica de Catalunya, Eduard
Maristany, 10-14, 08019 Barcelona, Catalonia, Spain
4 Laboratorio de Bajas Temperaturas, Departamento de Física de la Materia Condensada,
Condensed Matter Physics Center (IFIMAC) and Instituto Nicolás Cabrera, Universidad
Autónoma de Madrid, Francisco Tomás y Valiente 7, 28049 Madrid, Spain
Here we have experimentally investigated heat capacity and thermal conductivity of glassy
crystal pentachloronitrobenzene (PCNB, C6Cl5NO2) and thermal conductivity of solid
thiophene (C4H4S) in two different glassy crystal states1,2.3
. These glassy crystals formed by
cyclic molecules are low-dimensional and display highly anisotropic crystal structures.
Despite the similarity of the in-plane reorientational motions of the molecules within the solid
phases, it is found that only C6Cl5NO2 system has glassy anomalies at low temperature (a
boson peak and a density of tunneling two-level systems) typical for amorphous solid. Solid
thiophene in two different orientational states has crystal-like temperature dependence of
thermal conductivity. Results were analyzed within the framework of soft potential model.
Our study reveals that those glassy features can be found in a system with minimal disorder as
that due to the freezing of mostly in-plane reorientational jumps of molecules between
crystallographic equivalent positions with partial site occupation. It is found that fully glassy
behavior, namely a boson peak and a density of tunneling two-level systems comparable to
canonical (isotropic) molecular glasses or orientationally-disordered crystals is possible in a
highly anisotropic orientational glass-former with low-dimensional disorder. Our findings
help for understanding the origin of the controversial topic of low-temperature glassy
properties.
REFERENCES
1. Romanini M., Barrio M., Capaccioli S., Macovez R., Ruiz-Martin M.D. and Tamarit J.Ll., Double Primary
Relaxation in a Highly Anisotropic Orientational Glass-Former with Low-Dimensional Disorder, J. Phys.
Chem. C. 120, 10614-10621 (2016).
2. Korolyuk, O.A., Krivchikov, A.I., Vdovichenko G.A., Romantsova, O. O. and Gorbatenko, Y. U., Thermal
conductivity of solid thiophene in incommensurate orientational phase. Fizika Nizkikh Temperatur. 42, 89-
96 (2016).
3. Vdovichenko G.A., Korolyuk, O.A., Krivchikov and A.I, Romantsova O.O., Molecular disorder effects in
the thermal conductivity of solid thiophene, Low Temperature Physics. 40, 1112-1115 (2015).
ORAL CONTRIBUTIONS Boson-P-11
Invited Talk
Anomalous phonon scattering and elastic
correlations in amorphous solids
Simon Gelin1,2
, Hajime Tanaka2, Anaël Lemaître
1
1 Laboratoire Navier,UMR 8205, École des ponts, IFSTTAR, CNRS, UPE,
Champs-sur-Marne, France
2 Institute of Industrial Science, University of Tokyo,
4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
A major issue in materials science is why glasses present low-temperature thermal and
vibrational properties that sharply differ from those of crystals. In particular, long-wavelength
phonons are considerably more damped in glasses, yet it remains unclear how structural
disorder at atomic scales affects such a macroscopic phenomenon. A plausible explanation is
that phonons are scattered by local elastic heterogeneities that are essentially uncorrelated in
space, a scenario known as Rayleigh scattering, which predicts that the damping of acoustic
phonons scales with wavenumber k as kd+1
(in dimension d). Here we demonstrate that
phonon damping scales instead as −kd+1
ln k, with this logarithmic enhancement originating
from long-range spatial correlations of elastic disorder caused by similar stress
correlations [1,2]. Our work suggests that the presence of long-range spatial correlations of
local stress and elasticity may well be the crucial feature that distinguishes amorphous solids
from crystals [3].
REFERENCES
1. Lemaître, A., Structural Relaxation is a Scale Free Process, Phys. Rev. Lett.. 113, 245702 (2014).
2. Lemaître, A., Tensorial analysis of Eshelby stresses in 3D supercooled liquids, J. Chem. Phys. 143, 164515
(2016).
3. Gelin, S., Tanaka, H., Lemaître, A., Amorphous phonon scattering and elastic correlations in amorphous
solids, Nature Mat., 15, 1177–1181 (2016)
Brillouin-LS-1 ORAL CONTRIBUTIONS
Invited Talk
Bio-mechanical and bio-chemical analysis of living cells
investigated by correlative Brillouin and Raman micro-
spectroscopy
S. Caponi1, M. Mattarelli
2, S. Mattana
2, K. Sagini
3, L. Urbanelli
3, C.
Emiliani3,4
M. Dalla Serra5, D. Fioretto
2,4
1 Istituto Officina dei Materiali del CNR (CNR-IOM) - Unità di Perugia, c/o Department of
Physics and Geology, University of Perugia, Perugia, Italy
2. Dipartimento di Fisica e Geologia, Università di Perugia, Via A. Pascoli, I-06100 Perugia,
Italy
3 Laboratory of Biochemistry and Molecular Biology, Department of Chemistry, Biology and
Biotechnology, University of Perugia, via del Giochetto, I-06123 Perugia, Italy.
4 CEMIN-Center of Excellence for Innovative Nanostructured Material, Perugia, Italy.
5 Istituto di Biofisica CNR (IBF-CNR), Unità di Trento, and FBK, Via Sommarive 18, 38123
Trento, Italy
It is widely recognized that inelastic light scattering spectroscopies, such as Brillouin and
Raman, can achieve key information on the mechanical properties, the structure and the
chemical composition of materials. Due to their label free and contactless character, they
represent powerful tools for biomaterials investigation even under physiological conditions.
Using a new home-made experimental apparatus [1], simultaneous Brillouin and Raman
analysis can be obtained investigating with sub-micrometric resolution a large variety of
samples including opaque and heterogeneous materials. In this talk, the correlative Brillouin
and Raman spectroscopy is used to study mechanical properties of living cells also
monitoring their chemical composition. The unprecedented statistical accuracy of the
Brillouin data, permits the accurate line shape analysis. The complete characterization of the
viscoelastic properties of sub-cellular compartments is obtained considering the buffer
presence inside the scattering volume and the widening of the Brillouin peak, induced by the
uncertainty in the q exchanged due to the wide numerical aperture of the microscope
objective.
Acknowledgment: Work also funded by the “MaDEleNA” Project (Grandi Progetti 2012, Autonomous Province
of Trento).
REFERENCES
1. F. Scarponi et al. submitted to PRX
ORAL CONTRIBUTIONS Brillouin-LS-2
Invited Talk
Brillouin Light Scattering Spectroscopy Study of the
Viscoelastic properties of Blood Plasma
Kareem Elsayad
The viscoelastic properties of blood are known to play an important role for many processes
necessary for survival (tissue prefusion, oxygen delivery and circulation etc.). They are
understood to be dominated by the dense red blood cell suspension, with the plasma modelled
as a Newtonian fluid that serves as an extracellular matrix whose mechanical properties do
not vary significantly. As a result, much effort has been devoted to studying the mechanical
properties of red blood cells, variations of which have been linked to numerous hereditary and
metabolic disorders [1]. However, recent studies have shown a non-Newtonian viscoelastic
behavior of plasma [2]. Though the biochemical composition of plasma can change at the
onset of diseases, it is unclear if and how the structural-mechanical properties are affected.
Here we address this by studying the high frequency viscoelastic properties of blood plasma
from healthy, anemic and leukemia afflicted mice using Brillouin Light Scattering
Microspectroscopy (BLSM). BLSM utilizes the inelastic scattering of light from inherent
thermal density fluctuations (acoustic phonons) in a sample to derive mechanical parameters
such as the Longitudinal Storage and Loss Moduli. Since BLSM probes very fast (GHz range)
relaxation processes, it is sensitive to structural/conformational changes of individual
macromolecules – and probes a regime that is inaccessible using conventional perturbation
based mechanical characterization. We use an optimized variation [3] of a cross-dispersion
VIPA based spectrometer first proposed in Ref [4], that is capable of accurately discerning
very small spectral shifts and peak shapes. By mapping the variation and scaling of the
storage and loss parameters as a function of dilution and temperature we observe subtle
differences between plasma from healthy and diseased mice. We discuss possible origins and
implications of these differences, and the potential for novel diagnostic applications.
REFERENCES
1. Tomaiuolo, G., Biomechanical properties of red blood cells in health and disease towards microfluidics,
Biomicrofluidics 8, 051501 (2014).
2. Brust, M. et al., Rheology of Human Blood Plasma: Viscoelastic Versus Newtonian Behavior, Phys Rev let
110, 078305 (2013).
3. Elsayad, K et al., Mapping the subcellular mechanical properties of live cells in tissues with fluorescence
emission–Brillouin imaging, Science Sig. 9, rs5 (2016).
4 Scarcelli, G. Yun, H-G, Confocal Brillouin microscopy for three-dimensional mechanical imaging. Nature
Phot. 2, 39 (2008).
Brillouin-LS-3 ORAL CONTRIBUTIONS
Invited Tal
Simultaneous Brillouin-Raman micro-spectroscopy
F. Scarponi,1 S. Mattana,
2 S. Corezzi,
2 S. Caponi,
3 L. Comez,
3 F. Palombo,
4
and D. Fioretto2
1 Tablestable Ltd., Im Grindel 6, CH-8932 Mettmenstetten, Switzerland
2 Dipartimento di Fisica e Geologia, Università di Perugia, Italy
3 IOM-CNR c/o Dipartimento di Fisica e Geologia, Università di Perugia, Italy
4 University of Exeter, School of Physics and Astronomy, Exeter EX4 4QL, UK
Brillouin light scattering, providing information on the viscoelastic properties of matter [1], has
recently been applied to biological [2] and biomedical fields [3,4] through confocal microscopy
set-ups. On the other hand, micro-Raman techniques, giving information on the molecular
composition and structure of matter, has been used for long time in a number of fields, including
biophotonics and clinical applications. Recently, the conventional barrier between the two
techniques is crumbling and increasing interest is devoted to combined Brillouin - Raman light
scattering investigations [5-7], opening the route towards the correlative study of mechanical and
molecular properties of heterogeneous matter. Here, a new concept of multimodal micro-
spectroscopy is presented, that enables simultaneous detection of Brillouin and Raman light
scattering in a wide spectral range - from fractions of GHz to hundreds of THz [8]. It yields an
unprecedented 150 dB contrast, which is especially important for the analysis of opaque or turbid
media such as biomedical samples, and a spatial resolution on the sub-cellular scale. We report
results on the application of this new multimodal method to a range of systems, from single cells
to the mechano-chemical mapping of histological sections of tissue biopsy.
REFERENCES
1. L. Comez, C. Masciovecchio, G. Monaco, and D. Fioretto, Progress in Liquid and Glass Physics by
Brillouin Scattering Spectroscopy, in Solid State Physics, 1st ed., pp. 1–77 (Elsevier, 2012).
2. K. Elsayad, et al., Mapping the subcellular mechanical properties of live cells in tissues with fluorescence
emission–Brillouin imaging, Science Signaling. 9, rs5, (2016).
3. G. Scarcelli, et al. Noncontact three-dimensional mapping of intracellular hydromechanical properties by
Brillouin microscopy, Nature Methods. 12, 1132 (2015).
4. G. Antonacci, et al., Quantification of plaque stiffness by Brillouin microscopy in experimental thin cap
fibroatheroma, Journal of The Royal Society Interface. 12, 20150843 (2015).
5. F. Palombo, M. Madami, N. Stone, and D. Fioretto, Mechanical mapping with chemical specificity by
confocal Brillouin and Raman microscopy, Analyst. 139, 729 (2014).
6. F. Palombo, M. Madami, D. Fioretto, Chemico-mechanical imaging of Barrett's oesophagus, J. Nallala, H.
Barr, A. David, and N. Stone, Journal of Biophotonics. 9, 694 (2016).
7. S. Mattana, et al. Viscoelasticity of amyloid plaques in transgenic mouse brain studied by Brillouin
microspectroscopy and correlative Raman analysis, J. Innov. Opt. Health Sci. 23, 1742001 (2017).
8. F. Scarponi et al., High-performance versatile setup for simultaneous Brillouin-Raman micro-spectroscopy,
submitted to PRX; arXiv:1702.06707 (2017).
ORAL CONTRIBUTIONS Brillouin-LS-4
Invited Talk
Viscoelastic properties and biochemical composition of
amyloid plaques investigated by correlative Brillouin and
Raman micro-spectroscopies
Sara Mattana, a*
Silvia Caponi, b Francesco Tamagnini,
c Daniele Fioretto,
a
and Francesca Palombo d
a University of Perugia, Department of Physics and Geology, Perugia I-06123, Italy
bConsiglio Nazionale delle Ricerche, Istituto Officina dei Materiali - c/o Department of
Physics and Geology, Perugia I-06123, Italy
cUniversity of Exeter, Medical School, Hatherly Laboratories, Exeter EX4 4PS, UK
dUniversity of Exeter, School of Physics, Exeter EX4 4QL, UK
Alzheimer’s disease (AD) is the main cause of dementia worldwide. Amyloidopathy, one of
the two major hallmarks of AD [1], is characterized by the accumulation of amyloid plaques
formed by extracellular deposits of amyloid-β (Aβ) protein aggregates in the brain
parenchyma. Brillouin microspectroscopy is a contactless optical technique which detects
light scattered by collective modes, such as acoustic waves (phonons) propagating at GHz
frequencies, probing the viscoelastic properties of matter [2]. Raman scattering also deals
with scattered light, however this results from optical phonons or intramolecular modes
probing the vibrational frequencies of chemical bonds, with frequency shifts typically larger
than 1 THz.
Here, we present the first application of mechanical mapping based on Brillouin
microspectroscopy with correlative Raman scattering to amyloidopathy in the hippocampal
subfield of an Aβ overexpressing transgenic mouse model of AD.
We analysed ex vivo histological sections of mouse brain and obtained maps of mechanical
properties in correspondence to chemical composition of the tissue. The complex structure of
amyloid plaques, with a rigid core of β-amyloid protein surrounded by a soft region richer in
lipids and other protein conformations has been revealed, hence showing the capability of
Brillouin-Raman microspectroscopy to detect amyloidopathy in tissue histologies. [3] These
results open the route to further developments, potentially towards in vivo applications
through suited optical approaches.
REFERENCES [1] HARDY J. A., HIGGINS G. A., ALZHEIMER’S DISEASE: THE AMYLOID CASCADE HYPOTHESIS.
SCIENCE 1992, 256 (5054), 184-5.
[2] Edginton, R.S., Mattana, S., Caponi, S., Fioretto, D., Green, E., Winlove, C.P., Palombo, F.
Preparation of Extracellular Matrix ProteinFibers for Brillouin Spectroscopy. J. Vis. Exp. 2016(115),
e54648
[3] S. Mattana, S. Caponi, F. Tamagnini, D. Fioretto and F. Palombo, Journal of Innovative Optical
Health Sciences Vol. 10, No. 5 (2017)
Brillouin-LS-5 ORAL CONTRIBUTIONS
Invited Talk
Viscoelasticity of Extracellular Matrices
Francesca Palombo,a* Ryan S. Edginton,
a Ellen Green,
a Nick Stone,
a
C. Peter Winlove,a and Daniele Fioretto
b
a University of Exeter, School of Physics, Exeter EX4 4QL, UK
b University of Perugia, Department of Physics and Geology, Perugia I-06123, Italy
The biomechanics of tissues and their constituents are key properties that affect normal tissue
function, and disturbances in these properties are widely implicated in aging and disease. The
extracellular matrix is the scaffolding for cells and solutes in tissues. It is made up of the
structural proteins collagen and elastin, whose fibres are the fundamental mechanical
structures in connective tissues such as bone, cartilage, lung, skin and the vasculature. As a
novel biophotonic technique, Brillouin light scattering (BLS) spectroscopy offers an all-
optical contactless approach to the study of the mechanics of complex systems such as
biological samples on a microscale. Through the propagation of thermally induced acoustic
waves or phonons, BLS gives access to the elasticity or stiffness of the material, hence
offering a valuable contrast mechanism to detect abnormalities that can form the basis of
novel diagnostics, but also to answer fundamental questions in biology and medicine.
We applied BLS spectroscopy and microscopy to investigate the micromechanics and
structure of collagen and elastin fibres, as well as connective, epithelial and brain tissue, and
the effect of hydration [1-5]. This contribution will focus on the heterogeneity of extracellular
matrices in these specimens, and how the correlative use of Raman scattering spectroscopy
and quasistatic stress-strain testing can provide complementary approaches to interpret the
mechanical response in the GHz (BLS) spectral region.
REFERENCES
1. Mattana, S., Caponi, S., Tamagnini, F., Fioretto, D., Palombo F. Viscoelasticity of amyloid plaques in transgenic
mouse brain studied by Brillouin microspectroscopy and correlative Raman analysis, Journal of Innovative
Optical Health Sciences. 23, 1742001 (2017).
2. Palombo, F., Madami, M., Fioretto, D., Nallala, J., Barr, H., David, A., Stone, N. Chemo-mechanical imaging of
Barrett's oesophagus, Journal of Biophotonics. 9, 694-700 (2016).
3. Edginton, R.S., Mattana, S., Caponi, S., Fioretto, D., Green, E., Winlove, C.P., Palombo, F. Preparation of
extracellular matrix protein fibers for Brillouin spectroscopy, Journal of Visualized Experiments. 115 (2016).
4. Palombo, F., Winlove, C.P., Edginton, R.S., Green, E., Stone, N., Caponi, S., Madami, M., Fioretto, D.
Biomechanics of fibrous proteins of the extracellular matrix studied by Brillouin scattering, Journal of the Royal
Society Interface. 11 (2014).
5. Palombo, F., Madami, M., Stone, N., Fioretto, D. Mechanical mapping with chemical specificity by confocal
Brillouin and Raman microscopy, Analyst. 139, 729-733 (2014).
ORAL CONTRIBUTIONS Brillouin-LS-6
Invited Talk
High-contrast, single-pass Fabry-Perot interferometers by
field equalization
Giuseppe Antonacci1, Simone De Panfilis
1, Giuseppe Di Domenico
1,2, Eugenio
DelRe2, Giancarlo Ruocco
1
1Center for Life Nano Science, Istituto Italiano di Tecnologia, V.le Regina Elena 291, 00161
Roma, Italy
2Deptartment of Physics, Sapienza University, P.le Aldo Moro 5, 00185 Rome, Italy
Spectral contrast in Fabry-Perot (FP) interferometers is key to measure weak signals. In Brillouin microscopy, a
sufficient spectral contrast is especially important when probing high-scattering biological systems due to
formation of parasitic elastic crosstalk lines overwhelming the weak Brillouin signals [1-2]. Several promising
methods have been developed to suppress the elastic background in Brillouin measurements [3-5], yet the
intrinsic contrast of FP interferometer still remained unvaried. Existing methods to increase the spectral contrast
involve the use of multiple spectral devices, such as FP etalons and diffraction gratings, placed in series and
operating in a beam multipassing mode [6]. However, multi-stage spectrometers involve a large number of
optical and mechanical components, which generally affect the overall throughput efficiency of the device.
The limit on the spectral contrast achievable by standard FP interferometers and etalons is ultimately dictated by
the transmission Airy function, which is composed of subsequent Lorentzian peaks characterized by long
frequency tails that limit the peak-to-background ratio. At its heart, this limit is a consequence of an unbalanced
field amplitude across multiple interfering paths, with an ensuing reduced fringe visibility. Here, we demonstrate
an intensity equalization method to achieve an unprecedented 1000-fold increase in spectral contrast in a single-
pass, high-throughput VIPA spectrometer [7]. A spatial light modulator (SLM) was used to shape the output
beam of the VIPA by displaying an appropriate intensity mask of semi-Gaussian profile along the dispersion axis
of the etalon. In turn, a spectral contrast of ~60dB was readily achieved by our equalized spectrometer. To
validate the method, we obtained the Brillouin spectrum of water at high scattering concentrations where, unlike
with the standard scheme, the inelastic peaks were highly resolved.
References
1. Scarcelli, G. et. al. Noncontact three-dimensional mapping of intracellular hydromechanical properties by
Brillouin microscopy. Nature Methods, 12(12), 1132-1134 (2015).
2. Antonacci, G., Braakman, S. Biomechanics of subcellular structures by non-invasive Brillouin microscopy.
Scientific Reports 6, 37217 (2016).
3. G. Antonacci, G. Lepert, C. Paterson, and P. Torok, Elastic suppression in Brillouin imaging by destructive
interference. Applied Physics Letters, 107(6), 061102 (2015).
4. Meng, Z., Traverso, A. J., Yakovlev, V. V. Background clean-up in Brillouin microspectroscopy of scattering
medium. Optics express, 22(5), 5410-5415 (2014).
5. Antonacci, G. Dark-field Brillouin microscopy. Optics Letters, 42(7), 1432-1435 (2017).
6. Scarcelli, G., Yun, S. H. Multistage VIPA etalons for high-extinction parallel Brillouin spectroscopy. Optics
express, 19(11), 10913-10922 (2011).
7. Antonacci, G., De Panfilis, S., Di Domenico, G., DelRe, E., Ruocco, G. Breaking the Contrast Limit in Single-
Pass Fabry-Pérot Spectrometers. Physical Review Applied, 6(5), 054020 (2016).
Colloids-1 ORAL CONTRIBUTIONS
Invited Talk
The glass transition of soft colloids
A.-M. Philippe1, D. Truzzolillo
1, J. Galvan-Myoshi
2, P. Dieudonné-George
1,
V. Trappe2, L. Berthier
1, L. Cipelletti
1
1 Laboratoire Charles Coulomb (L2C), UMR 5221 CNRS-Université de Montpellier,
Montpellier, France
2 University of Fribourg, Department of Physics, CH-1700 Fribourg, Switzerland
We explore the glassy dynamics of soft colloids using microgels and charged particles
interacting by steric and screened Coulomb interactions, respectively. In the supercooled
regime, the structural relaxation time of both systems grows steeply with volume fraction,
reminiscent of the behavior of colloidal hard sphere systems. Computer simulations confirm
that the growth of on approaching the glass transition is independent of particle softness.
By contrast, softness becomes relevant at very large packing fractions when the system falls
out of equilibrium. In this non-equilibrium regime, depends surprisingly weakly on
packing fraction and time correlation functions exhibit compressed exponential decays
consistent with stress-driven relaxation. The transition to this novel regime coincides with the
onset of an anomalous decrease of local order with increasing density, reminiscent of the
reentrant glass transition predicted theoretically in ultrasoft systems.
We propose that these peculiar dynamics result from a competition between the non-
equilibrium aging dynamics of the glassy state and the tendency of soft systems to refluidize
at high packing fractions.
ORAL CONTRIBUTIONS Colloids-2
Invited Talk
Autocatalytic aggregation of patchy particles
Silvia Corezzi1, Cristiano De Michele
2, Francesco Sciortino
2
1 Dipartimento di Fisica e Geologia, Università di Perugia, Via Pascoli, Perugia, Italy
2 Dipartimento di Fisica, Università di Roma ‘La Sapienza’, Piazzale A. Moro 5, Roma, Italy
Autocatalysis is a very common mechanism in chemistry, is important in life and probably played
a central role in its origin on Earth [1]. Beyond this issue, it comes into play in a number of
biologically relevant processes as well as in the production of engineering materials [2]. Despite
their pervasiveness in nature and science, autocatalytic reactions have so far remained out of reach
of realistic numerical simulations. Patchy particle models, in particular, can be thought as
archetypal of real systems and have proved to be very useful to study the thermodynamic and
structural properties of several associating fluids, both molecular and colloidal [3]. Nevertheless,
the particle aggregation mechanism in these models lacks autocatalysis. Here, we derive a mean-
field equation that describes a general autocatalytic reaction and implement it in a binary mixture
of limited valence patchy particles, with tunable efficiency of the autocatalytic reaction pathway
[4]. Simulations allow us to penetrate secrets of the aggregation process that are experimentally
inaccessible, revealing (i) the unexpected effect of activation barriers and (ii) how the kinetics of
autocatalytic reactions can be exactly predicted by tracing it back to varying noncatalytic
conditions. In particular, the barrier effect successfully explains fine details of the kinetics
observed in simulations, in a way exportable to the description of real systems, as confirmed by
experimental data on epoxy resins.
The impact of our results is on three levels. On a general level, they are of relevance to all
activated processes in physics, chemistry, and related fields. On the specific level of the
experimental case investigated, they physically explain the observed kinetics of epoxy resin
systems, resolving the apparent contradiction of systematic deviations from mechanistic models.
On a prospective level, we provide the first simulation tool to study under controlled conditions a
number of realistic aggregation processes where autocatalysis is active.
REFERENCES
1. Bissette, A. J., Fletcher, S. P., Mechanisms of autocatalysis, Angew. Chem. Int. Ed. 52, 2–30 (2013).
2. Szavits-Nossan, J., et al., Inherent Variability in the Kinetics of Autocatalytic Protein Self-Assembly, Phys.
Rev. Lett. 113, 098101 (2014). Naskar, A.K., Keum, J.K., Boeman, R.G., Polymer matrix nanocomposites
for automotive structural components, Nat. Nanotechnol. 11, 1026 (2016).
3. Corezzi, S., Fioretto, D., Sciortino, F., Chemical and physical aggregation of small-functionality particles,
Soft Matter 8, 11207 (2012). Smallenburg, F., Sciortino, F., Liquids more stable than crystals in particles
with limited valence and flexible bonds, Nat. Phys. 9, 554 (2013). Salamonczyk, M., et al., Smetic phase in
suspensions of gapped DNA duplexes, Nat. Comms. 7, 13358 (2016).
4. Corezzi, S., De Michele, C., Sciortino, F., Autocatalytic aggregation of patchy particles, in preparation.
Colloids-3 ORAL CONTRIBUTIONS
Invited Talk
Questioning the relationship between the 4 susceptibility
and the dynamical correlation length in a glass former
Rémy Colin1, A. M. Alsayed
2, Cyprien Gay
1 and Bérengère Abou
1
(1) Matière et Systèmes Complexes, CNRS & Université Paris Diderot, Paris, France
(2) Complex Assemblies of Soft Matter Laboratory, UMI CNRS 3254, Solvay INC., Bristol,
Pennsylvania, USA
Clusters of fast and slow correlated particles, identified as dynamical heterogeneities (DHs),
constitute a central aspect of glassy dynamics. A key factor of the glass transition scenario is a
significant increase of the cluster size 4 as the transition is approached. We investigate DHs
in dense microgel suspensions using image correlation analysis, and compute both the
dynamical susceptibility 4 and the four-point correlation function G4. The spatial decrease of
G4 provides a direct access to 4, which is found to grow significantly with increasing volume
fraction. However, this increase is not captured by 4. We show that the assumptions that
validate the connection between 4 and 4 are not fulfilled in our experiments.
REFERENCES
1. Colin, R., Alsayed, A. M., Gay, C., Abou, B., Soft Matter. 11, 9020-9025 (2015).
ORAL CONTRIBUTIONS Colloids-4
Invited Talk
Arrested Spinodal Decomposition and Formation of
Glasses, Gels, and Porous Glasses
M. Medina-Noyola, J. M. Olais-Govea, L. López-Flores
Instituto de Física “Manuel Sandoval Vallarta”, Universidad Autónoma de San Luis Potosí,
Álvaro Obregón 64, 78000 San Luis Potosí, SLP, México
In contrast with equilibrium crystalline solids, whose properties are not preparation-
dependent, non-equilibrium amorphous solids may exhibit aging and their properties do
depend on their preparation protocol [1]. The non-equilibrium self-consistent generalized
Langevin equation (NE-SCGLE) theory of irreversible processes in liquids [2] was recently
shown to provide a simple and intuitive first-principles description [3] of the non-equilibrium
relaxation of model glass-forming liquids with purely repulsive interparticle interactions near
their high-density transition to repulsive, hard-sphere–like glasses. Still more recently [4] the
same theory, applied to model liquids with repulsive plus attractive interactions, was shown to
predict a still richer and more complex scenario including, in addition to hard-sphere glasses
at high densities and temperatures, the formation of sponge-like gels and porous glasses by
arrested spinodal decomposition at low densities and temperatures.
In this work we discuss the predicted kinetics of the formation of these arrested disordered
structures, which turns out to be equally complex and subtle. For example, contrary to the
mild structural response characteristic of the formation of hard-sphere glasses, the structural
evolution that follows a sudden quench of a liquid to the interior of its spinodal region is
characterized by the dramatic amplification and eventual arrest of gigantic density (and hence,
dynamical) heterogeneities. This is evidenced by the development of a small wave-vector
spinodal decomposition peak in the predicted non-equilibrium static structure factor S(k;tw),
whose height increases and whose position kmax(tw) decreases with waiting time tw, until the
mean size (tw) = 2/kmax(tw) of these heterogeneities saturates at a finite asymptotic value a
that depends on the final density and temperature of the quench. We demonstrate the
experimental relevance of these predictions by their comparison with simulation and
experimental data
References
1. Angell C. A. et al., J. Appl. Phys. 88 3113 (2000).
2. P. E. Ramírez-González and M. Medina-Noyola, Phys. Rev. E 82, 061503 (2010).
3. L. E. Sánchez-Díaz et al., Phys. Rev. E 87, 052306 (2013).
4. J. M. Olais-Govea et al., J. Chem Phys. 143, 174505 (2015)
Colloids-5 ORAL CONTRIBUTIONS
Oral
Mermin-Wagner fluctuations in 2D amorphous solids
B. Illing, S. Fritschi, H. Kaiser, C.L. Klix, G. Maret, P. Keim
Affiliation(s), Address(es)
In a recent commentary, Mike Kosterlitz described how David Thouless and he got motivated
to investigate melting and suprafluidity in two dimensions [1]. It was due to the lack of broken
translational symmetry in two dimensions - doubting the existence of long range magnetism and
crystals in 2D - and the first computer simulations foretelling 2D crystals (at least in tiny systems).
The lack of broken symmetries, proposed by David Mermin and Herbert Wagner, is caused by long
wavelength order-parameter fluctuations [2,3]. Those fluctuations do not only have structural impact
but additionally a dynamical one: They cause the Lindemann criterion to fail in a 2D crystal in the
sense that the mean squared displacement of atoms is not limited. Differences between the 2D and 3D
glass transition were recently reported in large scale computer simulations [4]. Taking Mermin-
Wagner fluctuations into account those differences can be explained naturally. Comparing
experimental data from 3D and 2D amorphous solids with 2D crystals, we disentangle Mermin-
Wagner fluctuations from glassy structural relaxations [5].
The results are consistent with the work of Vivek et al. who investigated 2D and 3D glasses with short
and long range particle interaction [6]. Recently Hayato Shiba and coworkers verified Mermin-
Wagner fluctuations in large scale computer simulations using an alternative approach [7]: The density
of vibrational states of a 2D amorphous solid shows an infinite growth of acoustic vibrations, very
similar to 2D crystals. Furthermore, the fingerprint of Mermin-Wagner fluctuations, namely the
logarithmic increase of displacements with system size, was now demonstrated in 2D glass [5,7] - fifty
years after the prediction in symmetry breaking systems: crystallinity is not a requirement for Mermin-
Wagner fluctuations which conserve the homogeneity of space and soften 2D ensembles in the
thermodynamic limit.
REFERENCES [1] J.M. Kosterlitz: ‘Ordering, metastability and phase transitions in two-dimensional systems’—the early basis
of the successful Kosterlitz–Thouless theory, Jour. Phys. Cond. Mat. 28, 481001 (2016)
[2] N.D. Mermin, H. Wagner: Absence of ferromagnetism or antiferromagnetism in one- or 2-dimensional
isotropic heisenberg models, Phys. Rev. Lett., 17, 1133 (1966),
[3] N.D. Mermin: Crystalline order in 2 dimensions, Phys. Rev., 176, 250 (1968)
[4] E. Flenner, G. Szamel: Fundamental differences between glassy dynamics in two and three dimensions, Nat.
Commun., 6, 7392 (2015)
[5] B. Illing, S. Fritschi, H. Kaiser, C.L. Klix, G. Maret, P. Keim: Mermin–Wagner fluctuations in 2D
amorphous solids, PNAS 114, 1856 (2017)
- see comments in PNAS 114, 2440 (2017) and Nature Physics 13, 205 (2017)
[6] S. Vivek, C. P. Kelleher, P.M. Chaikin, E.R. Weeks: Long-wavelength fluctuations and the glass transition in
two dimensions and three dimensions, PNAS 114, 1850 (2017)
[7] H. Shiba, Y. Yamada, T. Kawasaki, K. Kim: Unveiling dimensionality dependence of glassy dynamics: 2D
infinite fluctuation eclipses inherent structural relaxation, Phys. Rev. Lett. 117, 245701 (2016)
ORAL CONTRIBUTIONS Colloids-6
Invited Talk
Tunable Slow Dynamics in a New Class of Soft Colloids
Angel J. Moreno1,2,*
, Federica Lo Verso2,3
, José A. Pomposo1,4,5
,
Juan Colmenero1,2,4,5
1Centro de Física de Materiales (CSIC, UPV/EHU) and Materials Physics Center MPC,
Paseo Manuel de Lardizabal 5, E-20018 San Sebastián, Spain
2Donostia International Physics Center (DIPC),
Paseo Manuel de Lardizabal 4, E-20018 San Sebastián, Spain
3Department of Physics, Chemistry and Pharmacy, Syddansk Universitet,
Campusvej 55, DK-5230 Odense, Denmark
4IKERBASQUE, Basque Foundation for Science,
María Díaz de Haro 3, E-48013 Bilbao, Spain
5Departamento de Física de Materiales, Universidad del País Vasco (UPV/EHU),
Apartado 1072, E-20080 San Sebastián, Spain
By means of extensive monomer-resolved simulations, we investigate concentrated solutions
of globular single-chain polymer nanoparticles (SCNPs), an emergent class of synthetic soft
nano-objects. By increasing the concentration, the SCNPs show flattening and reentrant
behaviour in the density dependence of their structural and dynamic correlations, as well as a
soft caging regime and weak dynamic heterogeneity. The latter is confirmed by validation of
the Stokes–Einstein relation up to concentrations far beyond the overlap density. Therefore
SCNPs arise as a new class of soft colloids, exhibiting slow dynamics and actualizing in a real
system (the macromolecular architecture has been explicitly simulated) the static and dynamic
anomalies proposed by models of single ultrasoft particles. Quantitative differences in the
dynamic behaviour depend on the SCNP deformability, which can be tuned through the
degree of internal cross-linking.
Colloids-7 ORAL CONTRIBUTIONS
Invited Talk
Glass transition temperature of polymer colloidal particles
Y.Cang1, B. Graczykowski
1, H.Kim
2, E.M.Furst
2, R.D. Priestley
3,G.Fytas
1
1Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
2Unversity of Delaware, Newark, DE 19716, USA
3Princeton University, NJ 08544, USA
Polymer colloids are important materials in technologies ranging from drug delivery to
coatings to fillers in photonics. In these applications, it is the physical properties of the
colloids, e.g., the glass transition, that are of paramount importance. As such, experimental
studies on size, shape and surface confinement effects are warranted. While there is rich
literature in thin film geometry, only few papers are devoted to polymer nanoparticles and
polymer nanocomposites employing mainly differential scanning calorimetry (DSC).1.2
Here
we utilize Brillouin Light Scattering (BLS) to record the particle elastic eigenfrequencies3, the
temperature dependence of which yields information on glass dynamics. We have examined
four different polystyrene (PS) colloids (bare PS spheres, core/shell, PS/SiO2 and PS
dumbbells) with different size, surface and colloidal architecture. For bare polymer colloids
two softening temperatures are resolved, the highest being comparable with the single glass
transition temperature (Tg) of the corresponding thick polymer films. The second low
softening transition temperature prevails in PS cores with soft confinement but is shifted to
higher temperatures. Alternatively, capping the PS cores with a hard (silica) shell4,5
leads to
homogeneous dynamics with a single, PS-like, glass transition. The dual softening transition
in the free-surface colloids is associated with the mobile surface and bulk core and dynamic
heterogeneity decreases with particle size. Due to the presence of particle adhesion, the lowest
frequency vibration associated with the breathing of colloidal molecules6 yields additional
information on the strength of interactions and particle dynamics. The particle vibration
results are complemented by modulated and nano DSC.
REFERENCES
1. C. Zhang, Y.Guo, R.Priestley, Glass Transition Temperature of Polymer Nanoparticles under Soft and Hard
Confinement, Macromolecules .44, 4001-4006 (2011).
2. S. Feng et al, Glass transition of polystyrene nanospheres under different confined environments in aqueous
dispersions, Soft Matter. 9, 4614-4620 (2013).
3. T. Still, et al, Eigenvibrations of Submicrometer Colloidal Spheres, J.Phys.Chem.Lett. 1,2440-2444 (2010).
4. T.Still,et al, Mesospheres in nano-armor: Probing the shape-persistence of molten polymer colloids
J.Coll.Inter. Sci. 340,42-45 (2009).
5. Y. Guo, et al, Structural Relaxation of Polymer Nanospheres under Soft and Hard Confinement: Isobaric
versus Isochoric Conditions, ACS Nano, 5, 5365-5373 (2011).
6. M.Mattarelli,et al, Vibration spectroscopy of weakly interacting mesoscopic colloids, Soft Matter 2012,8,
4235-4243 (2012).
ORAL CONTRIBUTIONS Colloids-8
Invited Talk
Local structure of Yukawa colloidal fluids – theory and
Monte Carlo simulations
Jacek Gapinski*, Adam Patkowski, Sebastian Wołoszczuk
Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan, Poland
In our recent articles [1-2] we showed experimental and theoretical studies of the
structure of Yukawa colloidal fluids. The SAXS experiments were performed on
monodisperse silica spheres suspended in dimethylformamide (DMF) with addition of lithium
chloride salt. The analysis and interpretation of the experimental results was based on
theoretical calculations of the structure of such colloidal system using Ornstein-Zernicke
equations with Rogers-Young (RY) closure relation. Theoretical RY calculations, initially
restricted to experimental conditions were extended to study the colloid structure in the
vicinity of the freezing line established by the Hanset-Verlet condition which relates the onset
of freezing to the principal peak height of the structure factor S(q). Phase diagrams obtained
in this way were expressed both in the representation of experimental parameters (volume
fraction, effective charge, salt concentration) and in the two dimensionless parameters space
~T-, where denotes the ratio of the Debye screening length -1 to the mean interparticle
distance r. The calculated radial distribution functions g(r) allowed for estimation of some
local order parameters like the number of nearest neighbors Nn. By relating the obtained
values of Nn to those characteristic for crystal structures of given symmetries (fcc, bcc), we
tried to determine the local structure of colloids close to the freezing line. Our results turned
out to be in agreement with computer simulations of such systems. In the current study we
perform Monte Carlo computer simulations of our system extending the space of interest to
both “more liquid” and “more crystalline” conditions. Apart from calculations of S(q), g(r)
and Nn we used the coordinates of the colloids to estimate the angular correlation functions
allowing for more certain characterization of the system with regard to its local symmetry.
For example, in systems with low values we found bcc-like local structure remaining in the
suspension even after dilution to volume fraction ~10-5
. A strong point of our approach is the
direct relation to experimental parameters both in RY calculations and in MC simulations.
REFERENCES
1. J. Gapinski, G. Nägele, and A. Patkowski, Freezing lines of colloidal Yukawa spheres. I. A Rogers-Young
integral equation study, J. Chem. Phys. 136, 024507 (2012)
2. J. Gapinski, G. Naegele, and A. Patkowski, Freezing lines of colloidal Yukawa spheres. II. Local structure
and characteristic lengths,, J. Chem. Phys. 141, 124505 (2014).
Oral
Colloids-9 ORAL CONTRIBUTIONS
A Structural-Dynamical Transition in Trajectory Space
Probed by Colloid Experiment
Rattachai Pinchaipat,1,2
Matteo Campo,3,4
Francesco Turci,1,2
James E.
Hallett,1,2
Thomas Speck,4 and C. Patrick Royall
1,2,5,6
1H.H. Wills Physics Laboratory, Tyndall Avenue, Bristol, BS8 1TL, UK
2Centre for Nanoscience and Quantum Information, Tyndall Avenue, Bristol, BS8 1FD, UK
3Graduate School Materials Science in Mainz, Staudinger Weg 9, 55128 Mainz, Germany
4Institut fu¨r Physik, Johannes Gutenberg-Universit¨at Mainz, Staudingerweg 7-9, 55128
Mainz, Germany
5School of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, UK
6Department of Chemical Engineering, Kyoto University, Kyoto 615-8510, Japan
One approach to understanding the glass transition is the identification of a non-equilibrium
phase transition in trajectory space which reveals phase coexistence between the normal
supercooled liquid (active phase) and a glassy state (inactive phase) [1] which to date has only
been identifies in computer simulation [2,3]. Here we present evidence that such a transition
occurs in colloidal hard sphere experiment [4]. In our 8% polydisperse colloidal hard spheres
system we find a non-Gaussian distribution of locally favoured structures (LFS) in trajectories
space has tendency towards those rich in LFS [5], associated with the emergence of slow
dynamics. This we interpret as evidence for a non-equilibrium transition to an inactive LFS-
rich phase. Reweighting trajectories reveals a first-order phase transition in trajectory space
between a normal liquid and a LFS-rich phase. We further find evidence of a purely
dynamical transition in trajectory space.
REFERENCES
1. R. L. Jack, M. F. Hagan, and D. Chandler. Fluctuation-dissipation ratios in the dynamics of self-assembl,y
Phys. Rev. E. 76, 021119 (2007).
2. L. O. Hedges, R. L. Jack, J. P. Garrahan, and D. Chandler., Dynamic Order-Disorder in Atomistic Models of
Structural Glass Formers, Science 323, 1309 (2009).
3. T. Speck, A. Malins, and C. P. Royall, First-Order Phase Transition in a Model Glass Former: Coupling of
Local Structure and Dynamics, Phys. Rev. Lett. 109, 195703 (2012).
4. R. Pinchaipat, M. Campo, F. Turci, J. Hallet, T. Speck, C.P. Royall, Experimental Evidence for a Structural-
Dynamical Transition in Trajectory Space ArXiV, 1609.00327 (2016).
5. A. Malins, S. R. Williams, J. Eggers, and C. P. Royall., Identification of structure in condensed matter with
the topological cluster classification, J. Chem. Phys. 139, 234506 (2013).
ORAL CONTRIBUTIONS Colloids-10
Oral
Kinetics of fullerene C60/C70 aggregation in polar liquids
and their mixtures with water
T.V. Tropin1, N. Jargalan
2, O.A. Kyzyma
1,3, M.V. Avdeev
1, V.L. Aksenov
4,1
1 Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
2 Institute of Physics and Technology, Mongolian Academy of Sciences, Ulaanbaatar,
Mongolia
3 Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
4 National Research Centre “Kurchatov Institute”, Moscow, Russia
Fullerenes, a new allotropic form of carbon discovered at the end of last century, provoke
much interest partly due to their ability to dissolve in various liquids and the interesting
effects that occur in their solutions [1]. These effects include clusters formation and growth,
solvatochromism and some others.
The present report is dedicated to theoretical and experimental investigation of fullerenes
aggregation in polar solutions. Slow growth of large fullerene clusters has been reported to
occur in these systems [2]. It is supposed to be connected with formation of charge-transfer
complexes between fullerene and solvent molecules [3]. We consider novel experimental data
for C60/N-methyl-pyrrolidone (NMP) solution, including DLS and UV-Vis kinetic
measurements. For theoretical description of aggregation a model system similar to C60/NMP
is considered and the approach based on kinetic theory of nucleation has been developed. The
cluster-size distribution functions within the model of limited growth are obtained for the
whole period of systems evolution.
Using the developed approach we also consider the critical effect of cluster decomposition in
C60/NMP solution, that occurs after water addition to the system [4]. This effect may be used
in the future for obtaining of fullerene-water solutions with given properties for biomedical
applications. The possible models for description of the effect are discussed.
REFERENCES
1. Avdeev, M.A., Aksenov, V.L., Tropin, T.V., Models of cluster formation in solutions of fullerenes, Russ. J.
Phys. Chem. A., 84 1273-1283 (2010).
2. Nath, S., Pal, H., Sapre, A.V., Effect of solvent polarity on the aggregation of C60, Chem. Phys. Lett. 327
143–148 (2000).
3. Kyzyma, O.A., Korobov, M.V., et al., Aggregate development in C60/NMP solution and its mixture with
water as revealed by extraction and mass spectroscopy, Chem. Phys. Lett. 493 103–106 (2010).
4. Aksenov, V.L., Avdeev, M.V., Tropin, T.V., et al., Formation of fullerene clusters in the system
C60/NMP/water by SANS, Phys. B Condens. Matter. 385–386 795–797 (2006).
Com-Cell-1 ORAL CONTRIBUTIONS
Invited Talk
A multiscale model of early cell lineage specification
including cell division
Alen Tosenberger1, Didier Gonze
1, Sylvain Bessonnard
2, Michel Cohen-
Tannoudji2, Claire Chazaud
3,4,5, Geneviève Dupont
1
1 Unité de Chronobiologie Théorique, Université Libre de Bruxelles (ULB), Faculté des
Sciences, Brussels, Belgium
2 Unité de Génétique Fonctionnelle de la Souris, UMR3738 CNRS/Institut Pasteur, Paris,
France
3 Clermont Université, Université d'Auvergne, Laboratoire GReD, Clermont-Ferrand, France
4 Inserm, UMR1103, Clermont-Ferrand, France
5 CNRS, UMR6293, Clermont-Ferrand, France
Embryonic development is a self-organized process during which cells divide, interact,
change fate according to a complex gene regulatory network and organize themselves in a
three-dimensional (3D) space. Here, we model this complex dynamic phenomenon in the
context of the acquisition of epiblast (Epi) and primitive endoderm (PrE) identities from the
inner cell mass (ICM) of the preimplantation embryo in the mouse. The pluripotent Epi cell
lineage is responsible for later development of the embryo, while PrE lineage gives rise to the
extraembryonic tissue. Nanog and Gata6, two characteristic genes for Epi and PrE lineages
respectively, are at first coexpressed in ICM cells. Later they become mutually exclusive
which leads to the cell development of Epi and PrE cells. Through the extracellular
communication, the two lineages stimulate their surrounding cells to adopt the opposite fate.
Thus they form the so-called "salt-and-pepper" pattern, which is important for the balance of
Epi and PrE cells in the embryo and the robustness of its early development. In this work, we
develop a 3D multi-scale model of early mammalian development, based on a previously
proposed GRN exhibiting tristability [1,2]. We propose a slight change to this GRN, we test
the robustness of the model and investigate possible origins of the heterogeneity (the salt-and-
pepper pattern).
REFERENCES
1. Bessonnard, S., De Mot, L., Gonze, D., Barrio,l M., Dennis, C., Goldbeter, A., Dupont, G., Chazaud, C.,
“Gata6, Nanog and Erk signaling control cell fate in the inner cell mass through a tristable regulatory
network”, Development. 141, 3637-48 (2014)
2. De Mot, L., Gonze, D., Bessonnard, S., Chazaud, C., Goldbeter, A., Dupont, G., “Cell Fate Specification
Based on Tristability in the Inner Cell Mass of Mouse Blastocysts”, Biophys J. 110, 710-22 (2015)
ORAL CONTRIBUTIONS Com-Cell-2
Invited Talk
Three-dimensional aggregation of tumor cells
Andrea Gamba
Institute of Condensed Matter Physics and Complex Systems
Department of Applied Science and Technology
Politecnico di Torino - 10129 Torino - Italy
Carcinomas are characterized by the disruption of the ordered multicellular architecture that is
typical of epithelial tissues. This process can be recapitulated in three-dimensional in vitro
experiments. Theoretical modeling and quantitative measurements suggest that disruption of
epithelial order is linked to fast non-equilibrium growth, even in the presence of regulatory
mechanisms with the potential of preserving a proper architecture [1]. Secondarily, aberrant
phenotypes may undergo transformations that lead tumor cells to invade neighboring tissues.
Invasion can occur either by isolated cells or by aggregates that migrate collectively.
Collective migration is presently suspected to confer a selective advantage to migrating cells.
The study of three-dimensional cancer cell cultures shows migrating cells eventually
aggregating in large clusters. Quantitative measurements of cluster velocity, coalescence and
proliferation rates suggest that such aggregation is driven by the exchange of diffusible
attractant factors (chemotaxis). This suggests an important role for chemotactic-driven
aggregation in the spreading and survival of tumor cells [2].
REFERENCES
1. Cerruti et al, Polarity, cell division, and out-of-equilibrium dynamics control the growth of epithelial
structures, J. Cell Biol. 203, 359-72 (2013).
2. Puliafito, A. et al, Three-dimensional chemotaxis-driven aggregation of tumor cells, Sci. Rep. 5, 15205
(2015).
Com-Cell-3 ORAL CONTRIBUTIONS
Invited Talk
Stem Cells and the Evolution of Organized Tissue:
an Emergent Behavior Prospective
Giorgio Gosti1, Alessandro Rosa
1,2, Maria Rosito
1, Davide Caprini
3, Valeria
de Turris1, Giancarlo Ruocco
1, Viola Folli
1
1Center for Life Nano Science, Istituto Italiano di Tecnologia, V.le Regina Elena 291, 00161
Roma, Italy
2Dept. of Biology and Biotechnology “Charles Darwin”, Sapienza University, P.le Aldo Moro
5, 00185 Rome, Italy
3Dipartimento di Ingegneria Meccanica e Aerospaziale, Sapienza University, Via Eudossiana
18, 00184 Roma, Italy
Recent studies discuss different types of emergent behaviors in cell populations, i.e.
patterning in embryos, or the order/disorder transition in epithelial cells. In vitro, under the
proper differentiation conditions, human induced Pluripotent Stem Cells (hiPSCs) form
highly symmetric circular structures of polarized cells, dubbed neural rosettes, that mimic the
spatial organization found in the early stages of the embryonic neural tube. We hypothesize
that rosettes are emergent and self-organized systems and that their spatial organization is
driven by the combination of fundamental molecular processes, mechanical conditions, and
cell-cell interactions. To study emergent behavior, we have designed a setup, composed of an
epifluorescent microscope and a stage-top CO2 incubator, capable of acquiring 1-2 weeks
time-lapse sequences. This setup has a 2 mm field width which allows us to capture the
emergence of neural rosettes from the very beginning of hiPSC differentiation. We have
generated modified hiPSCs in which the nuclear protein FUS/TLS is expressed in fusion with
a red fluorescent protein, tagRFP, resulting in permanent labeling of cell nuclei. In the image
analysis, first the fluorescent cell nuclei are detected from each image; then the tracking
algorithm constructs the cell trajectories and lineage trees from the detected cell nuclei.
Finally, we define an order parameter that quantifies the degree of organization and symmetry
of the emerging rosettes and characterize the phase transition of the cell population.
Preliminary results tell us that rosettes are emergent cells structures. We plan to develop a
specific formulation of cellular Potts models (CPM) that will predict the nucleation of rosettes
patterns and hiPSCs differentiation. A CPM may explain how local and global observables
influence a uniform population neural induction or patterned population neural/non-neural
induction. These prediction will be tested with the expression of the neural gene PAX6 that
marks the acquisition of a neural fate. In the long term our system might be useful to
understand the basis of neurodevelopmental diseases deriving from neural tube defects.
ORAL CONTRIBUTIONS Com-Cell-4
Invited Talk
Endocyticic reawakening of motility and flocking in
jammed epithelia
Roberto Cerbino
Università degli Studi di Milano, Dip. di Biotecnologie Mediche e Medicina Traslazionale
Dynamics of epithelial monolayers has recently been interpreted in terms of a jamming or
rigidity transition [1,2]. How cells control the proximity to that transition is, however,
unknown. Here we show that elevation of the endocytic protein RAB5A, frequently hijacked
by different epithelial-like tumors to promote their dissemination, is sufficient to induce large-
scale, coordinated motility and flocking in otherwise kinetically-arrested monolayers. Our
findings [3] suggest that the increased fluctuations and reawakening of motility are the result
of globally enhanced endosomal trafficking and macropinocytotic internalization. These
variations lead to an increase in junctional tension and traction forces exerted on the substrate
and promote the extension of persistent cell protrusions which align with local velocity. To
rationalize our findings, we propose a simple model where, in addition to cell-cell adhesion
and cortical tension, we consider an active reorientation mechanism for the velocity of self-
propelled cells. The model explains the observed reawakening of RAB5A motility in terms of
a combination of large-scale directed migration and a local unjamming [3,4]. These changes
in multicellular dynamics allow collectives to migrate under physical constraints and may be
exploited by tumors for interstitial dissemination.
REFERENCES
1. Angelini, T., et al., Glass-like dynamics of collective cell migration, PNAS. 108, 4714-4719 (2011).
2. Park J.A., et al., Unjamming and cell shape in the asthmatic airway epithelium, Nature Materials. 14, 1040-
1048 (2015)
3. Malinverno, C., Corallino, S., et al, Endocytic reawakening of motility in jammed epithelia, Nature
Materials. Advance Online Publication (2017)
4. Giavazzi, F., Paoluzzi, M., et al., to be submitted
Com-Phot-1 ORAL CONTRIBUTIONS
Invited Talk
Statistical physics insight into complex photonics: from
random lasers to light propagation in complex and random
media.
Luca Leuzzi
Soft and Living Matter (SliM) Lab. - CNR-NANOTEC, Institute of Nanotechnology,
c/o Dept. Physics, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185, Rome, Italy
In recent years a valuable description of the properties of waves in random media by means of
the tools of statistical mechanics has led to a deeper understanding and a wider range of
predictions on the behavior of complex photonic systems. These are systems where disorder,
non-linearity and wave interaction play significant, non-perturbative, roles possibly causing
the onset of a collective behavior of light modes. After giving a concise account of the formal
translation of the dynamics of the electromagnetic field of light onto a statistical mechanical
description we report on recent ideas and results on random lasers, in particular on those
compounds displaying glassy behavior, and on the transmission of light waves trough
complicated, disordered media.
REFERENCES
1. Tyagi P. et al., Regularization and decimation pseudolikelihood approaches to statistical inference in XY
spin models, Phys Rev. B. 94, 024203 (2016).
2. Antenucci, F., Crisanti, A. and Leuzzi, L., The glassy random laser: replica symmetry breaking in the
intensity fluctuations of emission spectra, Sci. Rep. 5, 16792 (2015), Complex sherical 2+4 spin-glass: A
model for nonlinear optics in random media, Phys Rev. A. 91, 053816 (2015).
3. Antenucci, F. et al., General phase diagram of multimodoal ordered and disordered lasers in closed and open
cavities, Phys. Rev. Lett. 114, 043901 (2015).
4. Ghofraniha, N. et al., Experimental evidence of replica symmetry breaking in random lasers, Nature
Commun. 6, 6058 (2015).
5. Marruzzo, A. and Leuzzi, L., Nonlinear XY and p-clock models on sparse random graphs: mode-locking
transition of localized waves, Phys, Rev. B, 91, 064202 (2015).
ORAL CONTRIBUTIONS Com-Phot-2
Invited Talk
Towards structural microscopy in strongly scattering media
Hilton B. de Aguiar,1 Sylvain Gigan,
2 Sophie Brasselet
3
1Ecole Normale Superieure/Paris, Paris 75005,
2Laboratoire Kastler Brossel, and Université Pierre et Marie Curie, 75005 Paris, France,
3Institut Fresnel, 13013 Marseille, France.
Polarization-resolved (PR) microscopies are able to provide molecular-level structural
insights beyond the diffraction-limited scale [1]. Unfortunately, the penetration depth of PR
approaches in scattering media is notoriously shallow, as multiple scattering inherently mixes
both polarization and spatial degrees of freedom, creating a random elliptically polarized
speckle. Under these circumstances, performing molecular-level structural imaging is
currently impossible at mm-depth in biological media as a deterministic relation between
input and output polarization degrees of freedom is not feasible.
Here, we show how to recover the injected polarization state, without using any polarization
selection at the detection [2], using wavefront shaping techniques [3,4,5]. This counter-
intuitive effect [6,7,8] occurs in thick samples that exhibit a speckle with elliptically polarized
grains. Most remarkably, an arbitrary rotation of the input polarization is directly transferred
to the focus polarization. Furthermore, we show second-harmonic generation images of
collageneous biological tissues in scattering environments, and how we enabled molecular-
level structural imaging using this new effect. Finally, the observation of this phenomenon –
polarization revival out of a scrambled polarization state – paves the way for molecular-level
structural microscopy in biomedical applications.
REFERENCES
1. Brasselet, S., “Polarization-resolved nonlinear microscopy: application to structural molecular and biological imaging,”
Adv. Opt. Photon. 3, 205–271 (2011).
2. de Aguiar, H. B., S. Gigan and S. Brasselet. “Polarization-resolved microscopy through scattering media via wavefront
shaping.” arXiv:1511.02347 (2015).
3. Vellekoop, I. M. and A. P. Mosk, “Focusing coherent light through opaque strongly scattering media,” Opt. Lett. 32,
2309–2311 (2007).
4. Popoff, S. M., G. Lerosey, R. Carminati, M. Fink, A. C. Boccara and S. Gigan, “Measuring the Transmission Matrix in
Optics: An Approach to the Study and Control of Light Propagation in Disordered Media,” Phys. Rev. Lett. 104, 100601
(2010).
5. de Aguiar, H. B., S. Gigan and S. Brasselet. “Enhanced nonlinear imaging through scattering media using transmission-
matrix-based wave-front shaping.” Phys. Rev. A 94, 043830 (2016).
6. Tripathi, S., R. Paxman, T. Bifano and K. C. Toussaint, “Vector transmission matrix for the polarization behavior of
light propagation in highly scattering media.” Opt. Express 20, 16067–16076 (2012).
7. Guan, Y., O. Katz, E. Small, J. Zhou and Y. Silberberg, “Polarization control of multiply scattered light through random
media by wavefront shaping.” Opt. Lett. 37, 4663–4665 (2012).
8. Park, J.-H., C. Park, H. Yu, Y.-H. Cho and Y.-K. Park. “Dynamic active wave plate using random nanoparticles.” Opt.
Express 20, 17010–17016 (2012).
Com-Phot-3 ORAL CONTRIBUTIONS
Invited Talk
Correlations between the transmitted and reflected speckle
patterns in scattering media
Jacopo Bertolotti
University of Exeter, Stocker Road, Exeter EX4 4QL, United Kingdom
When monochromatic light propagates through a scattering medium, it is scrambled and
produces a seemingly random speckle pattern. This randomization process prevents
information to pass through a turbid material, which behave like a screen and prevents us to
see through it. Yet, multiple scattering is not enough to completely decouple the two sides of
a turbid medium, as interference between the scattered waves is known to produce
correlations in the speckle patterns. In most cases these correlations can be used to extract
information about the turbid medium itself. An exception is the optical memory effect, that
connects the incident with the transmitted wavefront, and thus can be exploited to retrieve
information through an otherwise opaque screen. Here we present the experimental
characterization of a novel form of correlation that connects the reflected and the transmitted
speckle, potentially allowing to image through a scattering medium non-invasively,
measuring only the reflected light. We show that this correlation has both a short and a long-
range contribution, resulting in a very rich phenomenology.
ORAL CONTRIBUTIONS Com-Phot-4
Invited Talk
Disorder-induced single-mode transmission
Giancarlo Ruocco1,2
, Behnam Abaie3, Walter Schirmacher
1,2,4, Arash Mafi
3 &
Marco Leonetti1,5
1 Center for Life Nano Science@Sapienza, Istituto Italiano di Tecnologia, Viale Regina
Elena, 291 00161 Roma, Italia; 2 Department of Physics, University Sapienza, P.le Aldo Moro 5, I-00185 Roma, Italy;
3 Department of Physics and Astronomy, Center for High Technology Materials, University
of New Mexico, Albuquerque, New Mexico 87131, USA; 4 Institut für Physik, Universität Mainz, Staudinger Weg 7, D-55099 Mainz, Germany;
5 CNR NANOTEC-Institute of Nanotechnology c/o Campus Ecotekne, University of Salento,
Via Monteroni, 73100 Lecce, Italy
Localized states trap waves propagating in a disordered potential and play a crucial role in
Anderson localization[1-2], which is the absence of diffusion due to disorder. Some localized
states are barely coupled with neighbours because of differences in wavelength or small
spatial overlap, thus preventing energy leakage to the surroundings. This is the same degree of
isolation found in the homogeneous core of a single-mode optical fibre [3], a technology
representing today the backbone of our communication system. Here[4] we show that
localized states of a disordered optical fibre are single mode: the transmission channels
possess a high degree of resilience to perturbation and invariance with respect to the launch
conditions. Our experimental approach allows identification and characterization of the
single-mode transmission channels in a disordered matrix, demonstrating low losses and
densely packed single modes. These disordered and wavelength-sensitive channels may be
exploited to de-multiplex different colours at different locations.
REFERENCES
1. Lee, P. A. & Ramakrishnan, T. Disordered electronic systems. Rev. Mod. Phys. 57, 287 (1985).
2. Anderson, P. W. Absence of diffusion in certain random lattices. Phys. Rev. 109, 1492 (1958).
3. Ghatak, A. & Thyagarajan, K. An introduction to Fiber Optics (Cambridge University Press, 1998).
4. Ruocco, G., Abaie, B., Schirmacher, W., Mafi, A. & Leonetti, M., Disorder induced single mode
transmission, Nat. Commun. 8, 14571 (2017).
Com-Phot-5 ORAL CONTRIBUTIONS
Invited Talk
Pulse formation in mode locked lasers
Mark Popov and Omri Gat
Racah Institute of Physics, the Hebrew University, Jerusalem, Israel
Passive mode locking arises through the action of a saturable absorber, which initiates a
modulational instability in the uniform (cw) waveform, leading ultimately to the formation of
an ultrashort pulse. This nonlinear process compresses the cavity power through several
orders of magnitude of temporal intervals. I will show that it comprises qualitatively three
stages:
1. Nonlinear growth and narrowing toward a finite-time singularitiy
2. Clamping of the peak power by bandwidth saturation
3. Nonlinear relaxation
The first and last stages are studied with weakly nonlinear theory, while the strongly
nonlinear middle stage is described in terms of a Taylor series of growing exponentials. The
theory is validated using numerical simulations of the Haus mode locking model.
ORAL CONTRIBUTIONS Conf-TF-1
Invited Talk
Effects of Confinement on Tg and Stiffness in Polymer
Films Nanocomposites:
What are the Effects and Their Origin and How Can They
Be Suppressed or Eliminated?
John M. Torkelson
Department of Chemical and Biological Engineering
Department of Materials Science and Engineering
Northwestern University
Evanston, IL 60208
Seminal studies on polymers by Keddie, Jones and Cory in 1994 showed the importance of free
surfaces of films in reducing Tg and attractive interactions (hydrogen bonds) between polymer and
substrates in increasing Tg relative to Tg,bulk. Numerous studies have demonstrated that Tg values of
some confined polymer systems can be perturbed from bulk by many tens of degrees. Here, we shall
provide data that disproves one of the possible origins of these effects that is commonly considered
important in the research literature. Additionally, we shall provide evidence for the importance of
fragility in Tg-confinement effects. Other things being equal, the greater the value of fragility (and
hence the broader the relaxation distribution or greater the cooperativity required for relaxation), the
greater is the effect of free surfaces in reducing Tg in films lacking attractive substrate interactions. In
films that show reductions in Tg with confinement, there is also a reduction in fragility with
confinement. We have hypothesized that this fragility reduction is the underlying physical cause of the
Tg reduction. We support this hypothesis by demonstrating how fragility-confinement effects observed
with linear polymers of a particular species, e.g., polystyrene or poly(methyl methacrylate), can be
suppressed or eliminated by changes in polymer architecture, e.g., ring polymers, star polymers, cross-
linked polymers, dense brushes, etc., or with plasticizing additives. In cases where fragility-
confinement effects are strongly suppressed or eliminated, the Tg-confinement effects are also strongly
suppressed or eliminated. Additionally, by going to linear polymers with very low bulk fragility
values, e.g. some styrene-butadiene copolymers and versions of low molecular weight polystyrene, it
is possible for even linear polymer chains to exhibit almost total elimination of the Tg-confinement
effect. This knowledge is important in practical design of nanoconfined films or coatings or
nanocomposites that can maintain desired Tg response.
In many applications of films and nanocomposites, stiffness may be more important than the
absolute Tg value. As studied by a combination of molecular caging-sensitive fluorescence
measurables and AFM, we shall describe the important roles of free surfaces and hard and soft
substrates in modifying stiffness in glassy films and model nanocomposites. Furthermore, we shall
show that the length scales associated with these stiffness-confinement effects greatly exceed those
associated with Tg-confinement effects.
Conf-TF-2 ORAL CONTRIBUTIONS
Invited Talk
Interfacial properties of polymer nanocomposites: Role of
chain rigidity and dynamic heterogeneity length scale
Shiwang Cheng and Alexei P. Sokolov
Chemical Sciences Division, Oak Ridge National Laboratory,
Oak Ridge, Tennessee 37831, United States
While it is known that the properties of polymer nanocomposites are largely dominated by the
interfacial layer around nanoparticles,1 the molecular parameters controlling the interfacial
layer structure and dynamics remain unknown. In this work, we combine small angle x-ray
scattering, differential scanning calorimetry, and broadband dielectric spectroscopy to analyze
the dependence of the interfacial layer thickness, lint, on polymer rigidity defined through the
characteristic ratio, C∞. This analysis revealed a value of C∞~5-7, beyond which lint increases
substantially with C∞ and consistent with our earlier computer simulations.2 Moreover, lint
grows upon approaching the glass transition temperature from above and the rate of this
growth seems to correlate with polymer fragility. Most important, our analysis revealed that
lint is comparable to the characteristic length scale of dynamic heterogeneities in the studied
materials. These results provide new understandings of molecular parameters controlling the
interfacial layer, and are important not only for the field of polymer nanocomposites, but also
for the fields of thin polymer films, and dynamics of soft matter in general.
REFERENCES
1. Schadler, L. S., Kumar, S. K., Benicewicz, B. C., Lewis, S. L., and Harton, S. E., MRS Bull. 32, 335
(2007).
2. Carrillo, J.-M. Y., Cheng, S., Kumar, R., Goswami, M., Sokolov, A. P., and Sumpter, B. G.,
Macromolecules 48, 4207 (2015).
ORAL CONTRIBUTIONS Conf-TF-3
Invited Talk
Glass Transition Behavior of Thin Polymer Films: The
Effect of Molecular Architecture
Emmanouil Glynos1 and Peter F. Green
2
1Institute of Electronic Structure and Laser, Foundation for Research and Technology, P.O.
Box 1385, Crete, Heraklion, GR 71110, Hellas
2 Department of Materials Science and Engineering, University of Michigan, Ann Arbor,
48109, United States
A number of emerging applications of polymers, ranging from flexible electronics and energy
conversion cells, to active and passive coatings, involve their use in thin film geometries.
Nevertheless, many physical properties of polymer films with thicknesses, H, on the order of
tens on nanometers deviate substantially from those in the bulk as a result of entropic effects
associated with confinement and intermolecular interactions between the molecules and
external interfaces. One particular property that has extensively been studied is the glass
transition temperature, Tg. In this talk we will the role of macromolecular architecture, and in
particular the star-shaped architecture, on the structure and dynamics of polymers in confined
geometries. We will provide evidence that the vitrification behavior of polymers in thin film
geometries, may be tailored not by changing the monomer or the interface chemistry, but
simply by changing the macromolecular architecture. In particular, for star-shaped
polystyrenes (SPS) with small number of arms (functionality, f), and regardless of the degree
of polymerization or each arm (Narm), the Tg of SPS film on oxidized silicon substrates is
identical to their linear analogues (linear polystyrene, LPS) and the average Tg, decreases with
decreasing H (∆Tg < 0). However, with increasing f and/or decreasing Narm the Tg in thin films
increases in relation to the bulk and ∆Tg >0. Interestingly for sufficiently high f and
sufficiently short arm ∆Tg ≈0. In these situations, experiments and simulation experiments
show evidence of ordered organization of the molecules in the form of layers, in a manner
identical to soft colloid particles. The aforementioned behavior will be discussed in terms of
competing intermolecular entropic interactions associated with changes in f and Narm that alter
the ability of polymers to efficiently pack at surfaces and interfaces.
REFERENCES
1. Glynos, E, Frieberg, B, Green P.F.; Role of Molecular Architecture on the Vitrification of Polymer Thin
Films, Physical Review Letters, 106, 128301 (2011).
2. Glynos, E., et al. Vitrification of thin polymer films: from linear chain to soft colloid-like behavior,
Macromolecules 48, 2305-2312 (2015).
3. Glynos, E., et al. Surface relaxations of star-shaped macromolecular films. Submitted for Publication
Conf-TF-4 ORAL CONTRIBUTIONS
Invited Talk
Viscoelastic hydrodynamic interactions and anomalous CM
diffusion in polymer melts and confined films
Hendrik Meyer
Institut Charles Sadron, Université de Strasbourg, CNRS UPR22, 67034 Strasbourg, France
It was discovered recently that anomalous center-of-mass (CM) diffusion occurring on
intermediate time scales in polymer melts can be explained by the interplay of viscoelastic
and hydrodynamic interactions (VHI). The theory has been solved for unentangled melts in
3D [1] and 2D [2] and excellent agreement between theory and simulation of bead-spring
models is found. The physical mechanism considers that hydrodynamic interactions are
actually not screened in polymer melts. They are time dependent because of increasing
viscosity before the terminal relaxation time. This mechanism is generally active in melts of
any architecture (eg linear, ring, star) and it affects the dynamic structure factor of extended
objects (CM motion). The effect is most pronounced at early times which are in the time
window accessible by dynamic neutron scattering experiments. This talk will give a review of
the VHI theory and show recent simulation results of entangled polymer melts confined in
thin films where a continuous crossover from 3D-bulk to 2D can be observed in line with a
reduction of entanglements under confinement [3].
REFERENCES
1. Farago, J. et al. PRL 107, 178301 (2011); PRE 85, 051807 (2012).
2. Meyer, H., and Semenov, A. N., PRL 109, 248304 (2012); Soft Matter 9, 4249 (2013).
3. Lee, N., Diddens, D., Meyer, H., and Johner, A., PRL 118, 067802 (2017).
ORAL CONTRIBUTIONS Conf-TF-5
Invited Talk
Distribution of Glass Transition Temperature Tg in
Polymer Thin Films by Neutron Reflectivity and Low
Energy Muon
T. Kanaya1)
, R. Inoue2)
1)J-PARC MLF, KEK, Tokai-mura, Ibaraki, Japan,
2) KUR, Kyoto University, Kumatori,
Osaka, Japan
Properties of polymer thin films are very different from those of bulk and essential for the
industrial applications such as adhesives, lubricants, coating and so on. Hence, extensive
studies on polymer thin films have been performed for the past two decades to reveal
interesting but unusual properties of polymer thin films. One of the most interesting findings
is the thickness dependence of the glass transition temperature Tg revealed by various
experimental techniques. These studies suggest that polymer thin films have very
heterogeneous dynamics/structure along the depth direction, consisting of surface mobile
layer, middle bulk-like layer and interfacial hard layer.
To evaluate the heterogeneous dynamics of thin films directly, we have performed neutron
reflectivity measurements on 5-layer PS and PMMA thin films consisting of alternatively
stacked deuterated and hydrogenated PS (or PMMA) layers (dPS/hPS/dPS/hPS/dPS) [1] (or
dPMMA/hPMMA/dPMMA/hPMMA/dPMMA) [2]. Very clear distributions of Tg were
observed along the depth direction, showing the heterogeneous dynamics of polymer thin
films. Strictly speaking, however, nobody knows if there are any effects of labeling by D/H
on Tg. In order to see the effects of he D/H labeling, we have performed low energy muon
spin relaxation (LE- SR) experiments on a 5-layer dPS/hPS/dPS/hPS/dPS thin film, a single
layer dPS thin film and a single layer hPS thin film to measure the distribution of Tg [3]. The
results were compared with neutron reflectivity results [1] to see the effects of D/H labeling
and the characteristic features of the SR measurements.
.
References
[1] R. Inoue, K. Kawashia, K. Matsui, T. Kanaya, K. Nishida, G. Matsuba, M. Hino, Phys. Rev. E 83,
21801 (2011).
[2] R. Inoue, M. Nakamura, K. Matsui, T. Kanaya, K. Nishida, M. Hino, Phys. Rev. E 88, 032601
(2013).
[3] T. Kanaya, H. Ogawa, M. Kishimoto, R. Inoue, A. Suter, T. Prokscha, Phys. Rev. E, 92, 22604
(2015).
Conf-TF-6 ORAL CONTRIBUTIONS
Invited Talk
Flow Dynamics of Polymer Films – Effects of Interfaces and
Chemical Modifications
Ophelia K. C. Tsui
Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay,
Hong Kong and Boston University, Boston, MA, USA
Unlike simple liquids, polymers usually solidify by the glass transition, a process in which the
viscosity of the liquid increases by several orders of magnitude as the temperature is lowered
below the glass transition temperature (Tg). Recently, numerous studies show that the Tg of many
polymer films changes with the film thickness when the thickness is decreased to the nanometer
range. Because viscosity diverges at the glass transition, this implies that even a small change in
the Tg can translate into a significant change in the viscosity and thereby flow dynamics of a film.
To assess the flow dynamics of thin films down to nanometer thicknesses, we prepared polymer
films that are smoother than equilibrium. As such, they roughened spontaneously on heating. By
modeling the roughening process by thermally activated surface capillary waves, we accounted
for the observed surface evolution and determined the effective viscosity.1 With this approach,
we studied the effective viscosity of several thin film systems.1-3 By varying the polymer and
substrate materials, we adjusted the interactions between the polymer and substrate surface. By
varying the polymer chain length, we adjusted the degree of confinement imposed on the polymer
chains by the film thickness. Our results showed that the thickness dependences found of the
effective viscosity can be explained by existence of dynamic heterogeneity in the films, and how
the dynamic heterogeneity manifests in the flow dynamics can vary significantly with the degree
of confinement. More recently, we chemically modified our films by Ultra Violet Ozone (UVO)
treatment,4 which introduced functional groups to the polymer that interact strongly with the
substrate surface, and found that the effective viscosity of the films was significantly enhanced.
This result further demonstrates the significance of dynamic heterogeneity on the flow dynamics
of polymer nano-films, and opens possibilities to manipulate this and the related properties.
REFERENCES
1. Yang, Z., Fujii, Y., Lee, F. K., Lam, C.-H., Tsui, O. K. C., Glass Transition Dynamics and Surface Layer
Mobility in Unentangled Polystyrene Films, Science, 328, 1676-1679 (2010).
2. Li, R. N., Chen, F., Lam, C.-H., Tsui, O. K. C. Viscosity of Polymethylmethacrylate on Silica: Epitome of
Systems with Strong Polymer−Substrate Interactions, Macromolecules, 46, 7889-7893 (2013).
3. Geng, K. Katsumata, R., Xu, X. Ha, H. Dulaney, A. R., Ellison, C. J., Tsui, O. K. C., Conflicting
Confinement Effects on the Tg, Diffusivity and Effective Viscosity of Polymer Films: A Case Study with
Poly(Isobutyl Methacrylate) on Silica and Possible Resolution, Macromolecules, 50, 609-617 (2016).
4. Yu, X., Beharaj, A., Grinstaff, M. W., Tsui, O. K. C., Modulation of the Effective Viscosity of Polymer
Films by Ultraviolet Ozone Treatment, Polymer (2017).
ORAL CONTRIBUTIONS Conf-TF-7
Invited Talk
Hard vs. Soft Confinement: Local Glass Transition
Temperature Tg(z) Near and Across Glassy-Rubbery
Polymer Interfaces
Connie B. Roth, Roman R. Baglay, and Xinru Huang
Department of Physics, Emory University, Atlanta, Georgia, USA
Polymer-polymer interfaces are ubiquitous in polymer blends and block copolymers, while
opening up another avenue for the study of interfacial perturbations to the local glass
transition temperature Tg(z). We have previously reported the full local Tg(z) profile across a
glassy-rubbery polymer interface between polystyrene (PS) and poly(n-butyl methacrylate)
(PnBMA), an 80 K difference in bulk Tg [1]. By using local fluorescence measurements, we
revealed how the Tg(z) profile extends hundreds of nanometers away from the interface
showing an asymmetric behaviour penetrating deeper into the glassy PS side relative to the
composition profile. We have extended these measurements to investigate how the local Tg(z)
profile in PS varies when in contact with a variety of immiscible polymers whose Tgs vary
between +85 K and –80 K relative to the bulk Tg of PS, so-called hard vs. soft confinement.
This work focused on a single interface with semi-infinite domains, allowing the interfacial
disturbance to propagate unhindered by the presence of other interfaces, and bulk Tg to be
recovered far from the interface on either side. The data revealed that the onset of local Tg
deviation from bulk in PS occurs at two distinct length scales, which depend on whether PS is
the low Tg component (hard confinement) or the high Tg component (soft confinement) [2].
Here we explore various factors that aim to ascertain why these results exhibit such enormous
length scales: how does finite domain size truncate the Tg(z) profile, influence of faster
cooling rates, role of chain interpenetration and connectivity across the two domains. We are
particularly interested in understanding what appears to make polymer-polymer interfaces
distinctly different from other types of interfaces such as liquid, substrate, and free surfaces.
REFERENCES
1. Baglay, R. R., Roth, C. B., Communication: Experimentally Determined Profile of Local Glass Transition
Temperature Across a Glassy-Rubbery Polymer Interface with a Tg Difference of 80 K, Journal of
Chemical Physics. 143, 111101 (2015).
2. Baglay, R. R., Roth, C. B., Local Glass Transition Temperature Tg(z) of Polystyrene Next to Different
Polymers: Hard vs. Soft Confinement, Journal of Chemical Physics. 146, 203307 (2017).
Conf-TF-8 ORAL CONTRIBUTIONS
Invited Talk
Spatiotemporal characterization of confinement effects in
polymer thin films and nanoparticles
N. E. Israeloff and Andreea Panaitescu
Northeastern University, Boston, MA
The temperature-dependent length scale below a free polymer interface, over which dynamics
are sped-up, has been described in a recent cooperative string model by Salez et. al[1]. In this
theory, the thickness of the high-mobility layer is quite thin, 5-10 nm, of the order of the
length of cooperatively-relaxing-regions, but diverges very near the bulk glass transition, and
tends toward zero at the Vogel temperature. The model captures reasonably well the
reductions in glass transition temperature of certain supported ultra-thin PS films. A number
of experiments have detected a high mobility layer on some polymer films, e.g.by
nanoparticle (NP) embedding. But direct characterization of the temperature dependent
dynamics as function of depth on nm length scales below a free surface would be useful in
testing this model and any extensions of it. With this in mind we investigate spatiotemporal
dynamics in thin films of PVAc and PMMA, and measure dynamics of individual PMMA NP
through measurement of local polarization noise with a scanning non-contact probe.
In films we study spatio-temporal images, either a time series of xy images, or x-t
images near and below the glass transition. Polarization fluctuations are spatially and
temporally correlated. We show that the extent of spatial correlation can be related to the
depth of the source of the dynamics below the film surface. We find increasing spatial
correlation as Tg is approached, consistent with an increasing depth. We find faster dynamics
are less spatially correlated. We model this behavior in order to tease-out the depth and
temperature dependence of the dynamics. In NP we would expect stronger confinement
effects than for films. For PMMA NP from 25-80 nm in diameter, we find both conductivity
and structural-relaxation spectral peaks that are shifted to significantly lower temperatures,
and exhibit reduced fragility in comparison to bulk. Broadened structural peaks are observed
in large particles but become so broad as to become almost peak-less in the smallest particles.
We attempt to understand all of these observations in terms of theory.
REFERENCES
1. Saleza, T., Salez, J., Dalnoki-Veress, K., Raphaël, E., and Forrest J.A. Cooperative strings and glassy
interfaces, , PNAS, 112 8227 (2015).
ORAL CONTRIBUTIONS Conf-TF-9
Invited Talk
Friction at the interface between solid self-assembled
monolayers and liquid polymers or solid metal nanotips
J.D. McGraw
Département de Physique, Ecole Normale Supérieure/Paris Sciences et Lettres (PSL)
Research University, CNRS, 75005 Paris, France
The friction between a solid and a liquid was historically assumed to be so large that fluid
molecules in contact with a solid boundary were stuck. Thus, the classical no-slip boundary
condition was applied. With the advent of micro- and nano-fluidics in the last decades,
however, this boundary condition has been observed to fail in many instances. Particularly, as
will be discussed here, a slip boundary condition is observed when unentangled polystyrene
(PS) dewets from a hydrophobic, alkylsilane self-assembled monolayer (SAM). This
boundary condition can furthermore be tuned over an order of magnitude by subtly changing
the SAM [1,2], indicating that the friction between solid and liquid is highly sensitive to
atomic level details. We have also investigated the friction between these same SAMs and a
solid metal tip of nanoscopic dimensions. Remarkably, this apparent solid/solid friction is
velocity dependent and exhibits a crossover from a linear to logarithmic scaling in the
velocity [3]. The results can be described in terms of a distribution of nanocontacts with very
weak stiffness compared to the expected one for metal/solid contacts. The work presented
here has been done in collaboration with the authors of refs. [1, 2,3].
REFERENCES
1. McGraw, J.D., Chan, T.-S., Maurer, S., Salez, T., Benzaquen, M., Raphaël, E., Brinkmann, M., Jacobs, K.,
PNAS, 113, 1168 (2016).
2. McGraw, J.D., Klos, M., Bridet, A., Hähl, H., Paulus, M., Castillo, J.M., Horsch, M., Jacobs, K., J. Chem.
Phys. 146, 203326 (2017).
3. McGraw, J.D., Nigues, A., Siria, A., Scaling crossover of the velocity dependence for solid/solid friction at
the nanoscale, submitted (2017).
Conf-TF-10 ORAL CONTRIBUTIONS
Invited Talk
Depth-dependent Relaxation of Polystyrene near Substrate
Interface
Hung Kim Nguyen1, Manabu Inutsuka
1, Daisuke Kawaguchi
2, and Keiji
Tanaka1,3
1Department of Applied Chemistry,
2Education Center for Global Leaders in Molecular Systems for Devices, and
3International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu
University, Fukuoka 819-0395, Japan
Using sum-frequency generation spectroscopy, we study a depth-resolved measurement of the
local conformation and chain relaxation of polystyrene (hPS) located at different distances
from the quartz interface.1 To control the distance from the quartz interface, deuterated
polystyrene (dPS) layers with thicknesses of 3.4, 7.5 and 20 nm were coated on the quartz
substrates. The hPS chains in direct contact with the substrate surface predominantly orient
their phenyl rings in a direction normal to the substrate. This conformation was found to be
barely relaxed when the film was annealed for 24 h at 423 K, higher than the bulk glass
transition temperature. In contrast, for the hPS chains supported on the dPS layer, the
orientation of phenyl rings of hPS became weaker with the annealing and this trend was more
significant with increasing distance from the quartz substrate. In particular, the orientation of
phenyl rings of hPS after annealing vanished at a distance of 20 nm. These results might
provide an important evidence of the difference in the relaxation dynamics of the PS chains
located at different distances from the quartz interface.2
REFERENCES
1. Nguyen, H. K., Inutsuka, M., Kawaguchi, D., Tanaka, K., Depth-resolved Local Conformation and Thermal
Relaxation of Polystyrene near Substrate Interface, J. Chem. Phys. 146, 203313 (2017).
2. Tanaka, K., Tateishi, Y., Okada, Y., Nagamura, T., Doi, M., Morita, H., Interfacial Mobility of Polymers on
Inorganic Solids, J. Phys. Chem. B. 113, 4571-4577 (2009).
ORAL CONTRIBUTIONS Conf-TF-11
Invited Talk
Interfacial Energy and Glass Temperature of Polymers
Confined to Nanoporous Alumina
George Floudas
University of Ioannina and Max-Planck Institute for Polymer Research
We first discuss the dynamics of capillary imbibition of entangled poly(ethylene oxide) (PEO)
melts within self-ordered nanoporous alumina templates (AAO). AAO contains arrays of
discrete-isolated, parallel, cylindrical pores that are uniform in length and diameter that have
been employed as model confining systems.We find that imbibition lengths deviate from the
classical Lucas – Washburn equation. In general, slower capillary rise is observed for shorter
chains and a faster capillary rise for longer chains [1]. Subsequently, we report on the effect of
interfacial energy on the glass temperature, Tg, of several amorphous polymers with various
glass temperatures and polymer/substrate interactions confined within the same AAO
templates. The polymers studied include: poly(phenyl methyl siloxane) (PMPS), poly(vinyl
acetate) (PVAc), 1,4 polybutadiene (PB), oligostyrene (PS), poly(dimethyl siloxane) (PDMS)
[2] and cis-1,4 polyisoprene (PI) [3]. The segmental dynamics and associated Tg’s are studied
by means of dielectric spectroscopy. The interfacial energy for the polymer/substrate
interface, γSL, is calculated with Young’s equation whereas the AAO membrane surface
energy is obtained by measuring contact angles for several reference liquids. We find that
interfacial energy play a significant role on the segmental dynamics of polymers under
confinement within AAO. There is a trend for a decreasing glass temperature relative to the
bulk with increasing interfacial energy [2]. PDMS exhibits the highest interfacial energy and
the highest reduction in glass temperature within AAO. Other effects that may also contribute
to changes in Tg are discussed.
In collaboration with Y. Yao, S. Alexandris, P. Papadopoulos, H.-J. Butt
REFERENCES
1. Yao, Y., Alexandris, S., Henrich, F., Aurnhammer, G., Steinhart, M., Butt, H.-J., Floudas, G. Complex
dynamics of capillary imbibition of poly(ethylene oxide) melts in nanoporous alumina. J. Chem. Phys. 146,
203320 (2017).
2. Alexandris, S., Papadopoulos, P., Sakellariou, G., Steinhart, M., Butt, H.-J., Floudas, G. Interfacial energy
and glass temperature of polymer confined to nanoporous alumina. Macromolecules 49, 7400 (2016).
3. Alexandris, S., Sakellariou, G., Steinhart, M., Floudas, G. Dynamics of unentangled cis-1,4 Polyisoprene
confined confined to nanoporous alumina. Macromolecules 47, 3895 (2014).
Conf-TF-12 ORAL CONTRIBUTIONS
Invited Talk
Complex Dynamics of Ultra-Thin Films of Blends of
Polystyrene/ Poly(vinyl methyl ether) by Nanosized
Relaxation Spectroscopy
Sherif Madkour, Paulina Szymoniak, Andreas Schönhals
Bundesanstalt für Materialforschung und –prüfung (BAM), Unter den Eichen 87, 12205
Berlin, Germany
In the course of miniaturizing modern technology down to the molecular scale, understanding
the materials behavior has to be investigated and deviations from the bulk have to be
understood. A combination of nano-sized relaxation spectroscopies (Broadband Dielectric
Spectroscopy (BDS) and Specific Heat Spectroscopy (SHS)) employing AC nanochip
calorimetry were utilized to investigate the glassy dynamics of ultra-thin films of blends of
Poly (vinyl methyl ether) (PVME) / Polystyrene (PS) (50:50 and 25/75 wt-%), which are
miscible in the bulk (thicknesses: 8nm - 200nm, film thickness was controlled by
ellipsometry, film topography by AFM). Both methods are sensitive to different probes;
where SHS senses entropy fluctuations BDS measures dipole fluctuations. For BDS
measurements, a recently developed nano-structured electrode sample arrangement is
employed. By measuring the dynamic glass transition in dependence of the film thickness,
SHS showed that the Tg of the whole film was strongly influenced by a nanometer-thick
surface layer at the polymer/air interface due to a self-assembling process. Compared to the
SHS results the BDS measurements show a completely different behavior. At high
temperatures the temperature dependence of the relaxation times of the films follows that of
bulk-like PS/PVME obeying the VFT-law. With decreasing temperature the temperature
dependence deviates from the VFT to an Arrhenius law where the apparent activation energy
decreases with decreasing film thickness. This is the first example where confinement
induced changes were observed by BDS for ultra-thin films. All results were analyzed in
detail in a comprehensive discussion.
REFERENCES
1. Yin, H. Madkour, S., Schönhals A., Unambiguous evidence for a highly mobile surface layer in ultrathin
polymer films by specific heat spectroscopy on blends, Macromolecules 48 4936-4941, (2015)
2. Madkour, S. Szymoniak, P., Schick, C., Schönhals, A., Unexpected behavior of ultra-thin films of blends of
polystyrene/poly(vinyl methyl ether) studied by specific heat spectroscopy, Journal Chemical Physics 146,
203321 (2017).
ORAL CONTRIBUTIONS Conf-TF-13
Invited Talk
Interfacial interaction and glassy dynamics in stacked thin
films of poly(methyl methacrylate)
T. Hayashi, K. Segawa, K. Sadakane, K. Fukao, N.L.Yamada*
Department of Physics, Ritsumeikan University, Kusatsu, 525-8577 Japan
*Neutron Science Division, Institute for Materials Structure Science,
KEK, Tokai, Naka 319-1106, Japan
We have measured neutron reflectivity and dielectric permittivity of alternately stacked thin
films of protonated and deuterated poly(methyl methacrylate) to elucidate correlation between
time evolutions of the interfacial structure and segmental dynamics in the stacked thin
polymer films during isothermal annealing process above the glass transition temperature.
The roughness at the interface between two thin layers increases with increasing annealing
time, while the relaxation rate and strength of the α-process decrease with increasing
annealing time. A strong correlation between the time evolutions of the interfacial structure
and the dynamics of the α-process during the annealing could be observed by neutron
reflectivity and dielectric relaxation measurements. This result suggests that the interfacial
dynamics plays a crucial role to determine the dynamics of thin polymer films.
REFERENCES
1. Hayashi, T., Segawa, K., Sadakane, K., Fukao, K., Yamada, N. L., J. Chem. Phys. 146, 203305 (2017).
2. Hayashi, T. and Fukao, K., Phys. Rev. E 89, 022602 (2014).
3. Fukao, K., Terasawa, T., Oda, Y., Nakamura, K., and Tahara, D., Phys. Rev. E, 84, 041808 (2011).
Conf-TF-14 ORAL CONTRIBUTIONS
Invited Talk
Effect of Interface Interaction on the Dynamics of Polymer
Thin Films Studied by Local Dielectric Spectroscopy
Riccardo Casalini1 Massimiliano Labardi
2, Charles M. Roland
1 1Chemistry Division, Naval Research Laboratory, Washington, D.C., United States
2CNR-IPCF, SS Pisa, Largo Pontecorvo 3, 56127 Pisa, Italy
Local dielectric spectroscopy, which entails measuring the change in resonance frequency of the
conducting tip of an Atomic Force Microscope to determine the complex permittivity of a sample with
high spatial (lateral) resolution, was employed to characterize the dynamics of thin films of poly(vinyl
methyl ketone) (PVMK) having different substrate and top surface layers. A free surface yields the
usual speeding up of the segmental dynamics, corresponding to a glass transition suppression of 6.5
deg. for 18 nm film thickness. This result is unaffected by the presence of a glassy, compatible
polymer, poly(vinyl phenol) (PVPh), between the metal substrate and the PVMK. However, covering
the top surface with a thin layer of the PVPh suppresses the dynamics [1]. The speeding up of PVMK
segmental motions observed for a free surface is absent due to interfacial interactions of the PVMK
with the glassy polymer layer. For comparison with the case of an incompatible polymer, the
segmental dynamics of poly(vinyl acetate) (PVAc) thin films were measured in the presence of the
aluminum substrate and in contact with poly(4-vinylpyridine), that is immiscible to PVAc, in the
glassy state. No differences in local dielectric relaxation were observed for the various interfaces,
including a PVAc/air interface [2]. These results demonstrate experimentally that capping of thin
films, even with a rigid material, does not necessarily affect the dynamics, since the speeding up
herein for capped PVAc was equivalent to that for the air interface. The sensitivity of the dynamics to
the nature of the interface affords a means to engineer thin films while maintaining or modifying the
desired properties. Our findings also may contribute to explain the discordant results that have been
reported in general for the effect of air versus rigid interfaces on the local segmental relaxation of
polymer thin films.
The work at NRL was supported by the Office of Naval Research, in part by code 332. CNR was
supporting in part through the Short Mobility Program STM2016.
REFERENCES
1. Casalini, R., Labardi, M., Roland, C.M., Dynamics of poly(vinylmethylketone) thin films studied by local
dielectric spectroscopy, Journal of Chemical Physics 146, 203315 (2017).
2. Casalini, R., Prevosto, D., Labardi, M., Roland, C.M., Effect of interface interaction on the segmental
dynamics of poly(vinylacetate) investigated by local dielectric spectroscopy, ACS Macro Letters 4, 1022
(2015).
ORAL CONTRIBUTIONS Conf-TF-15
Invited Talk
Glass Transition in Layered Polymeric Systems: Role of the
Interphase
Rajesh Khare, Sriramvignesh Mani, Rafikul Islam
Department of Chemical Engineering, Texas Tech University
Box 43121, Lubbock, TX 79409, USA
Interfacial polymeric systems such as nanocomposites, layered systems, supported
membranes, and thin films exhibit rich glass transition physics. The characteristics of glass
transition and chain dynamics in these systems are affected by a number factors including
polymer-substrate interactions, chain topology, and thickness of the interfacial region.
Molecular simulations provide the unique ability to investigate the effects of individual
factors on the glass transition phenomenon.
The system of interest in this presentation is a layered polymeric system consisting of
alternate layers of polymers with different stiffness. In the first part, physics of the problem
was studied by considering coarse grained models of polymer chains. The nature of the
interphase in these systems was altered by varying the stiffness disparity between the two
polymers that constitute the individual layers. Simulation results will be presented for the
effects of the characteristics of the interphase region on the volumetric behavior, glass
transition, and chain dynamics. The subtleties introduced by the specific chemistry of the
polymers were studied in the second part. For this purpose, a system consisting of alternate
layers of polyacrylate and polysulfone was studied using atomistically detailed simulations.
Effects of the chemical interactions on the nature of the interphase and the glass transition
behavior will be discussed.
Conf-TF-16 ORAL CONTRIBUTIONS
Invited Talk
Mechanisms of Polymer Adsorption onto Solid Substrates
David Nieto Simavilla* and Simone Napolitano
Polymer and Soft Matter Dynamics, Université libre de Bruxelles
Deviations from bulk the bulk properties at the interface between a polymer melt and a
substrate are of great importance in applications such as flexible electronics [1], organic solar
cells [2] and membrane separation [3]. These interesting phenomena are attributed to the
formation of an irreversible adsorbed layer [4]. Previous research has shown the final
adsorbed amount at long annealing times to be independent of temperature [5], but a rational
understanding of how the adsorption kinetics are affected by temperature is still missing.
Allegedly, the polymer/substrate interaction is governed by: 1) The molecular motion or
conformational changes of the polymer and 2) diffusion of chains towards the substrate due to
the long-range attraction forces of the interaction potential. To differentiate between the two
mechanisms, we compare the effect molecular motion and the interaction potential have on
the kinetics of adsorption through experimental and simulation results respectively. In the
case of molecular-assisted adsorption, the adsorbed layer growth rate at short annealing times
has an Arrhenius-like temperature dependence, while the final adsorbed amount at long
annealing times is independent of temperature. On the other hand, in the case of adsorption
due to an interfacial potential, the growth rate and the final adsorbed amount are both growing
functions of the ratio of potential depth and thermal energy. Additionally, we present
evidence of a linear relationship between the growth rates in the linear and logarithmic
regimes of adsorption for both molecular- and potential-assisted adsorption, indicating that
the pinning of chains and loops follow the same mechanism at short and long annealing times.
The analysis of these results provides new insights into the physics governing polymer
adsorption in thin films during annealing, which are key in order to control the
polymer/substrate interface formation kinetics and resulting properties.
REFERENCES
1. Napolitano, S., Staying conductive in the stretch. Science, 355(6320):24–25, (2017).
2. Li, G., Zhu, R., and Yang, Y., Polymer solar cells. Nature Photonics Review, 6:153–161, (2012).
3. Jackson, E. A. and Hillmyer M. A. Nanoporous membranes derived from block copolymers: From drug
delivery to water filtration. ACS Nano, 4(7):3548–3553, (2010).
4. Napolitano, S. and Sferrazza, M.. How irreversible adsorption affects interfacial properties of polymers.
Advances in Colloid and Interface Science, (2017).
5. Gin P., Jiang, N., Liang, C., Taniguchi, T., Akgun B., Satija S.K., Endoh M.K., and Koga, T.. Revealed
architectures of adsorbed polymer chains at solid-polymer melt interfaces. Phys. Rev. Lett., 109:265501,
(2012).
ORAL CONTRIBUTIONS Conf-TF-17
Invited Talk
Probing The Density Variation of Confined Polymer Thin
Films via Simple Model-independent Nanoparticle
Adsorption.
Yves Grohensa, G Vignaud
a, J.P. Chapel
e,f, A. Beena Unni
a,b, J. Giermanska
e,f
J. K. Balc, N. Delorme
d, A. Gibaud
d
a Univ. Bretagne Sud, FRE CNRS 3744, IRDL, F-56100 Lorient, France
b International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma
Gandhi University, Kottayam, Kerala, India 686560
c Centre for Research in Nanoscience and Nanotechnology, University of Calcutta,
Technology Campus, Block JD2, Sector III, Saltlake City, Kolkata, 700098, India
d LUNAM Université, IMMM, Faculté de Sciences, Université du Maine, UMR 6283 CNRS,
Le Mans Cedex 9, 72000, France
e CNRS, Centre de Recherche Paul Pascal (CRPP), UPR 8641, F-33600 Pessac, France
f Université de Bordeaux, Centre de Recherche Paul Pascal, F-33600 Pessac, France
After more than 2 decades of intense research, the density variation in confined polymer films
still remains a puzzling problem subject to controversy as the methods utilized to determine
the density are often model dependent. In this presentation, we expose a direct and model
independent method to detect the density/refractive index variations in polymer thin films
through the adsorption of ceria nanoparticles (NPs) onto their surface. The amount of
adsorbed NP scales with the polymer film refractive index, hence any increase/decrease in the
NP surface coverage directly indicates an increase/decrease in the film refractive index and
density. The link between the density variation of ultra-thin films and their Tg deviation will
be discussed.
Conf-TF-18 ORAL CONTRIBUTIONS
Invited Talk
Layer Resolved Nanorhelogy in Thin Polymer Films by
Noncontact Shear
Mithun Chowdhury, Yucheng Wang, Yunlong Guo and Rodney D. Priestley
Department of Chemical and Biological Engineering, Princeton Institute for the Science and
Technology of Materials, Princeton University,
Princeton, NJ 08544, USA
In geometrically confined polymers, as the confining dimension (e.g., thickness for thin films
or inter-particle spacing for nanocomposites) is reduced below a critical value, an increasingly
large portion of the polymeric material is directly in contact with interfaces or surfaces. In
these states of confinement, in which interfacial interactions and surfaces (1) can perturb
structure and dynamics, astonishing changes in material properties have been reported,
including in the glass transition temperature (Tg), fracture toughness, viscosity, modulus, and
compliance. How these changes in properties with confinement are related to interfacial
effects has emerged as major question and scientific challenge in the polymer science
community. In this investigation, we employ a unique non-contact capillary nanoshearing
(NCNS) method to directly probe, for the first time (2), nano-resolved gradients in the
rheological response of ultrathin polymer films as a function of temperature and stress.
Results show that ultrathin polymer films, in response to an applied shear stress, exhibit a
gradient in molecular mobility and viscosity that originates at the interfaces. We demonstrate
via complementary molecular dynamics simulations, that these gradients in molecular
mobility reflect gradients in the average segmental relaxation time. We have explored this
technique successfully in polystyrene films and recently extended it to poly (butyl
methacrylate) and poly(vinylpyrrolidone) to explore the role of varying attractive interfaces
on shear responses.
REFERENCES
1. Chowdhury, M., Priestley, R. D., Discrete mobility on the surface of glasses, PNAS.
10.1073/pnas.1701400114 (2017).
2. Chowdhury, M., Guo, Y., Wang, Y., Merling, W. L., Mangalara, J. H., Simmons, D. S., Priestley, R. D.,
Spatially distributed rheological properties in confined polymers by noncontact shear, J. Phys. Chem. Lett. 8
(6), 1229-1234 (2017).
ORAL CONTRIBUTIONS Conf-TF-19
Invited Talk
Decoupling between molecular mobility and glass transition
in confinement allows accessing low energy states
Daniele Cangialosi
Centro de Física de Materiales, Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
This contribution aims to provide compelling experimental evidence on the decoupling
between nonequilibrium dynamics, including the glass transition temperature (Tg) and
physical aging, and the rate of spontaneous fluctuations in polymeric glasses under
geometrical confinement, in particular those exhibiting large amount of free interface. Special
attention is devoted to calorimetric techniques where the two aspects can be unequivocally
separated by applying temperature perturbations either in the linear and non-linear regime. A
number of examples are provided where, despite the ubiquitous presence of a prominent
component with bulk-like linear dynamics, the Tg is suppressed and the rate of physical aging
accelerated in comparison to the bulk [1]. This outcome is discussed in view of the conceptual
difference between the two aspects of glass dynamics.
Altogether these results indicate that glasses exhibiting large amount of free interface are able
to maintain equilibrium, when cooled down, or recover it, when aged isothermally or heated
up, more efficiently that the corresponding bulk system. This fact, in combination with the
essentially bulk thermodynamics for films at thin as 30 nm [2], is exploited to access low
energy states. This is done following the physical aging of glassy 30 nm thick stacked
polystyrene films. In this way, glasses with fictive temperature as low as Tg – 70 K are
achieved. This result has deep implications on the existence of the (ideal) thermodynamic
glass transition and the solution of the Kauzmann paradox with vanishing configurational
entropy [3].
REFERENCES
1. Cangialosi, D., Alegria, A., and Colmenero, J., Prog. Pol. Sci. 54-55, 128-147 (2016).
2. White, R. P., Price, C. C., and Lipson, J. E. G., Macromolecules, 48, 4132-4141 (2015).
3. Boucher, V. M., Cangialosi, D., Alegria, A., and Colmenero, J., Phys. Chem. Chem. Phys., 18, 961-965
(2017).
Conf-TF-20 ORAL CONTRIBUTIONS
Invited Talk
Tg and Entropy Changes on Nanoconfinement of Chains
Sindee L. Simon
Department of Chemical Engineering, Texas Tech University, Lubbock, TX USA
The behavior of materials confined at the nanoscale has been of considerable interest over the
past several decades. Here, our focus is the influence of nanoconfinement on the entropy of
n-alkyl methacrylate chains. Using differential scanning calorimetry to follow the reaction,
we observe that the ceiling temperature decreases when the methacrylate reactions are
performed in nanopores and that the total entropy loss on going from monomer to polymer
increases upon nanoconfinement (i.e., the entropy of propagation, Sp, becomes a larger
negative value). These confinement effects are observed to become weaker as temperature
increases and as the n-alkyl group increases in size, from methyl to ethyl to butyl. The
entropy loss on confining a chain is expected to scale with nanoconfinement size and with
chain length, and the scaling relationships will be tested and compared to the literature. The
results will also be discussed in the context of other nanoscale confinement effects, such as
the Tg depression.
ORAL CONTRIBUTIONS Conf-TF-21
Invited Talk
The Dynamics and Mechanics of Confined Polymer Glasses
Robert A. Riggleman*1
, Emily Lin1, Robert Ivancic
2
1: Department of Chemical and Biomolecular Engineering
2: Department of Physics and Astronomy
University of Pennsylvania
After two decades of experimental and computational work, it is widely accepted that
nanoscale confinement strongly perturbs the dynamics associated with glass formation. The
presence of either a free surface or a non-wetting wall leads to a local enhancement of the
dynamics, while strongly absorbing walls can slow the dynamics of glass formers. These
qualitative trends have been observed in experiments through both direct and indirect
measures of the dynamics, and simulations that directly measure the local mobility exhibit
similar trends. In this talk, I will highlight some recent results for both the dynamic and
mechanical properties of confined glass-forming polymers. In the dynamic properties, we find
some trends that appear to be qualitatively different from what is found in experiments. In
addition, I will describe our recent efforts to examine the ductile-to-brittle transition in model
polymer nanocylinders. Using an isoconfigurational ensemble approach, we find that the
location of failure in these model polymer pillars is apparently determined by the local
packing of the pillar, and we subsequently turn to machine learning techniques to extract the
structural queues that lead to shear band formation. We find that fluctuations in the surface
roughness play a prominent role in the eventual location of a shear band, and that the
formation of the shear band proceeds from the surface and into the nanocylinder.
Conf-TF-22 ORAL CONTRIBUTIONS
Invited Talk
Nanoconfinement as a strategy to stabilize unstable guest
forms
T. Cordeiroa, J. Sotomayor
a, I. M. Fonseca
a, M. M. Cardoso
a, M. T. Viciosa
c,
F. Danèdeb, N. T. Correia
b and M. Dionisio
a
aLAQV-REQUIMTE/CQFB, Departamento de Química, Faculdade de Ciências e
Tecnologia,Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
bUniv. Lille, CNRS, UMR 8207, UMET, Unité Matériaux et Transformations, F 59000, Lille,
France.
cCQFM − Centro de Química-Física Molecular and IN − Institute of Nanoscience and
Nanotechnology, Instituto Superior Técnico, University of Lisbon, Avenida Rovisco Pais,
1049-001 Lisbon, Portugal.
Examples of inclusion of low molecular weight compounds in nanostructured silica matrices
with different pore sizes are provided; special focus is given to highly crystallizable guests.
To access the guest physical state in the prepared composites, differential scanning
calorimetry, X-Ray diffraction and attenuated total reflectance-Fourier transform infra-red
spectroscopy are used. The different techniques provided complementary information of a
molecular population that revealed to be distributed among different environments namely the
pore core, the inner pore wall and the outer surface. Amorphization and population
distribution are confirmed by the calorimetric detection of an abnormally wide and pore-size
dependent glass transition [1]. The guest mobility is probed by dielectric relaxation
spectroscopy allowing identifying at least two relaxation processes: a faster one associated
with mobility of neat-like guest molecules (-process) and a slower, generally dominant one,
due to the hindered mobility of guest molecules adsorbed at the inner pores wall (S-process).
The guest kept amorphous inside pores for long periods of time being able to be fully released
from the matrix. This points to a suitability to these composites as drug delivery systems in
which the drug release profile can be controlled by tuning the host pore size.
REFERENCES
1. Cordeiro. T.; Santos, A. F. M.; Nunes G.; Cunha G.; Sotomayor, J. C.; Fonseca, I. M.; Danède ,F.; Dias, C.
J.; Cardoso, M. M., Correia, N. T.; Viciosa, M. T.; Dionísio, M. Accessing the Physical State and
Molecular Mobility of Naproxen Confined to Nanoporous Silica Matrices. J. Phys. Chem. C. 120, 14390–
14401 (2016).
ORAL CONTRIBUTIONS Conf-TF-23
Invited Talk
Time and Temperature as Key Parameters Controlling
Dynamics and Properties of Low and High Molecular
Weight Glass-Formers at the Nanoscale.
Magdalena Tarnacka1,2
*, Olga Madejczyk 1,2
, Kamil Kaminski
1,2, and Marian
Paluch1,2
1 Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland
2 Silesian Center of Education and Interdisciplinary Research, University of Silesia, 75 Pulku
Piechoty 1A, 41-500 Chorzow, Poland
The effect of 2D confinement on the molecular dynamics of low and high molecular weight
glass-formers, as, i.e., triphenyl phosphite (TPP) and poly(propylene glycol) (PPG) has been
studied with the use of Broadband Dielectric Spectroscopy (BDS) and Differential Scanning
Calorimetry (DSC). It is shown that all observed realaxation processes become faster with
increasing degree of confinement. Interestingly, it is found that the crossover from VFT to the
Arrhenius-like behavior of molecular dynamics is strictly related to vitrification of the
adsorbed polymers and freezing of the system’s density. The presence of two subsets of
molecules of different dynamics (interfacial and core) allows to produce conditions, where
only one fraction (interfacial) is vitrified. Upon these conditions, annealed samples undergo
continuous changes reflected in a shift of dielectric processes (segmental and normal mode).
This unusual behavior was observed to be a reversible effect strictly governed by chain
diffusion, indicated by the coupling between the equilibration constant (τanneal) and the
relaxation times of normal mode (τNM). Our findings offer a better understanding of the
behavior of the spatially restricted soft matter and reveal the possibility of exploring aging
effects up to now not accessible for bulk materials.
Conf-TF-24 ORAL CONTRIBUTIONS
Invited Talk
Interfacial and Topological Effects on the Glass Transition
in Free-Standing Polystyrene Films
Alexey V. Lyulin
Group Theory of Polymers and Soft Matter, Department of Applied Physics, Technische
Universiteit Eindhoven, 5600 MB, Eindhoven, the Netherlands
I will discuss the very recent results of the united-atom molecular-dynamics computer simulations of
atactic polystyrene (PS), for the bulk and free-standing films of 2 nm – 20 nm thickness, and for both
linear and cyclic polymers comprised of 80 monomers. Simulated volumetric glass-transition
temperatures (Tg) [1,2] show a strong dependence on the film thickness below 10 nm [3]. The glass-
transition temperature of linear PS is 13% lower than that of the bulk for 2.5 nm-thick films, as
compared to less than 1% lower for 20 nm films. Our studies reveal that the fraction of the chain-end
groups is larger in the interfacial layer with its outermost region approx. 1 nm below the surface than it
is in the bulk. The enhanced population of the end groups is expected to result in a more mobile
interfacial layer and the consequent dependence of Tg on the film thickness. In addition, the
simulations show an enrichment of backbone aliphatic carbons and concomitant deficit of phenyl
aromatic carbons in the interfacial film layer. This deficit would weaken the strong phenyl-phenyl
aromatic interactions and, hence, lead to a lower film-averaged Tg in thin films, as compared to the
bulk sample. To investigate the relative importance of the two possible mechanisms (increased chain
ends at the surface or weakened - interactions in the interfacial region), the data for linear PS are
compared with those for cyclic PS. For the cyclic PS the reduction of the glass-transition temperature
is also significant in thin films, albeit not as much as for linear PS. Moreover, the deficit of phenyl
carbons in the film interface is comparable to that observed for linear PS. Therefore, chain-end effects
alone cannot explain the observed pronounced Tg dependence on the thickness of thin PS films; the
weakened phenyl-phenyl interactions in the interfacial region seems to be an important cause as well
[4]. I will also discuss the interface characteristics of polystyrene in free-standing thin films and on a
graphite surface simulated employing an explicit all-atom force field [5].
References
1. Ediger, M.D.; Forrest, J.A. Macromolecules, 47, 471-478 (2014).
2. Barrat, J.-L.; Baschnagel, J.; Lyulin, A.V. Soft Matter, 6, 3430-3446 (2010).
3. Hudzinskyy, D.; Lyulin, A.V.; Baljon, A.R.C.; Balabaev, N.K.; Michels, M.A.J. Macromolecules, 44, 2299-
2310 (2011).
4. Lyulin, A. V., Balabaev, N. K., Baljon, A. R.C., Mendoza, G., Frank, C. W. and Yoon, Do Y., J. Chem.
Phys., 146, 203314 (2017).
5. Lee, S., Lyulin, A. V., Frank C. W., Yoon Do Y., Interface characteristics of polystyrene melts in free-
standing thin films and on graphite surface from molecular dynamics simulations. Polymer,(2017)
ORAL CONTRIBUTIONS Conf-TF-25
Oral
The Effect of Thermal Stress on the Confinement of
Polymers Vitrificated in Nanotubes
Tengchao1,2
, Dongshan Zhou1, Xiaoliang Wang
1, Gi Xue
1
Department of Polymer Science and Engineering, School of Chemistry and Chemical
Engineering, Nanjing University, Nanjing 210093
Guangdong Provincial Key Laboratory of Nano-Micro Materials Research Center, School of
Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School,
Shenzhen 518055, China
Polymer infiltrated nanopores exhibits different cooling dynamics. We use multi-step
relaxation to study the relationship between thermal stress and the cooling rates. The
mismatch of coefficient of thermal expansion between the inorganic substrate and the
polymer may cause a five times larger stress on polymer chains during fast cooling
(quenching from the melt to glassy state, ~100 K/min) than that during slow cooling (~10
K/min). In case of fast cooling process, the polymer chain is subjected to the highest residual
stress and would most likely be peeled off from the walls, and exhibits one glass transition
temperature (Tg). The slow cooling could make the polymer chains stick tightly on the wall,
and results in two distinguished Tgs, associated with the mechanism of jamming theory. The
strong interfacial interaction could provide an anchoring effect on mechanically bonding for
polymer on porous substrate, which plays an important role in modern nano-fabrication.
Conf-TF-26 ORAL CONTRIBUTIONS
Invited Talk
Dynamic Mechanical Analysis of relaxations in confined
liquids and polymers
Wilfried Schranz
University of Vienna, Faculty of Physics, Boltzmanngasse 5, A-1090 Wien, Austria
Dynamic mechanical analysis (DMA) is a powerful tool for the study of low frequency
relaxations (0.01 – 100 Hz) in diverse materials. Here we review DMA-experiments
performed for a variety of glass forming systems, including molecular liquids1-3
(salol,
toluene, ortho-terphenyl) as well as water4 confined in nano-porous silica (Vycor and Gelsil)
with pore sizes between 2.5 and 10 nm. In all these cases we find clear confinement effects,
which will be discussed in the present talk. We compare some of the results with effects
recently found in phase segregated polyureas5 with varying segmental chain lengths. By
changing the volume fraction of hard domains in the soft matrix, we could tune the system
from a soft one with embedded hard domains to a hard one with soft inclusions6, which then
becomes very similar to the meso-porous silica/liquid system.
Acknowledgments: WS acknowledges financial support from the Austrian Science Fund
(FWF) Grant No. P28672-N36.
REFERENCES
1. Schranz, W., Puica, M.R., Koppensteiner, J., Kabelka, H. and Kityk, A.V. Heterogeneous relaxation
dynamics of nano-confined salol probed by DMA, Europhys. Lett. 79, 36003 (2007).
2. Koppensteiner, J., Schranz, W. and Puica, M.R. Confinement effects on glass forming liquids probed by
dynamic mechanical analysis, Phys. Rev. B 78, 054203 (2008).
3. Koppensteiner, J., Schranz, W. and Carpenter, M.A. Revealing the pure confinement effect in glass-forming
liquids by dynamic mechanical analysis, Phys. Rev. B 81, 024202 (2010).
4. Soprunyuk, V., Schranz, W. and Huber, P. Dynamic Mechanical Analysis of supercooled water in
nanoporous confinement, Europhys. Lett. 115, 46001 (2016).
5. Soprunyuk, V., Reinecker, M. and Schranz, W. On the behaviour of supercooled liquids and polymers in
nano-confinement. Phase Transitions 89, 695 (2016).
6. Reinecker, M., Soprunyuk, V., Fally, M., Sánchez-Ferrer, A. and Schranz, W. Two glass transition behavior
of polyurea networks: effect of the segmental molecular weight, Soft Matter 10 (31), 5729-5738 (2014).
ORAL CONTRIBUTIONS Conf-TF-27
Invited Talk
Impact of substrate roughness on segmental dynamics
Simone Napolitano and Anna Panagopoulou
Polymer and Soft Matter Dynamics, Université libre de Bruxelles
We have performed an extensive experimental investigation of the impact of substrate
roughness on the segmental dynamics of several polymers confined in 1-Dimension (thin
films geometry). Our results indicate an enhancement in relaxation rate upon increase of the
root mean square deviation from a flat substrate, and of the power spectral density at each
frequency. The deviation from bulk segmental time increases upon cooling, inducing a
reduction in glass transition temperature and in dynamic fragility. Such trends are in neat
disagreement with the outcome of molecular dynamics simulations of Lennard-Jones Liquids
and of model polymer chains, which, on the contrary, proposed slower dynamics and higher
glass transition temperatures in proximity of rougher substrates. Unexpectedly, the trend
observed in experiments is in agreement with the predictions for smoother interfaces. We
explain the latter findings via an increase in free interface – the portion of polymer surface not
in direct contact with the substrate – at larger substrate roughness, due to unfavorable wetting
conditions. The results are discussed within the framework of recent models considering a
perturbation in interfacial free volume content (molecular packing) at the origin of
confinement effects on glassy dynamics [1].
REFERENCES
1. Napolitano, S. Glynos, E., Tito, N. B. Glass transition of polymers in bulk, confined geometries, and near
interfaces Rep. Prog. Phys. 80 036602 (2017).
Conf-TF-28 ORAL CONTRIBUTIONS
Oral
Kinetic Pathways for Characterizing and Predicting the
Non-equilibrium Behavior of Polymer Films
Sivasurender Chandrana, Rishab Handa
a, Marwa Kchaou
b, Samer Al-
Akhrassb, Alexander N. Semenov
c and Günter Reiter
a
a Institute of Physics, University of Freiburg, 79104 Freiburg, Germany
b Ingénierie des Matériaux Polyméres IMP - UMR CNRS 5223, Université Claude Bernard
Lyon 1, Villeurbanne Cedex 69622, France
c Institut Charles Sadron CNRS, UPR 22, rue du Loess - BP 84047, F-67034, Strasbourg
Cedex 2, France
Performance and properties of materials may strongly depend on processing conditions. This
is particularly so for polymers, which often have relaxation times much longer than the
processing times and therefore may adopt preparation dependent non-equilibrated molecular
conformations that potentially cause novel properties. However, so far it was not possible to
predictably and quantitatively relate processing steps and resulting behavior of polymer films.
Here, we demonstrate that the behavior of polymers films, probed through dewetting, can be
tuned by controlled preparation pathways, defined through a dimensionless parameter P that
relates the processing time with the characteristic relaxation time of polymers. We revealed
scaling relations between P and the amount of preparation-induced residual stresses, the
corresponding relaxation time, and the probability of film rupture. Intriguingly, films of the
same thickness exhibited hole nucleation densities and subsequent dewetting kinetics
differing by up to an order of magnitude, indicating possibilities to adjust the desired
properties of polymer films by preparing them in appropriate ways.
ORAL CONTRIBUTIONS Conf-TF-29
Oral
Diffusion in Quasi-One-Dimensional Channels: A
Transition State Theory for Hopping Times
Sheida Ahmadi and Richard K. Bowles
Department of Chemistry, University of Saskatchewan, Saskatoon, SK, S7N 5C9 Canada
Brownian particles confined to narrow, quasi-one dimensional channels exhibit a
dynamic transition from single file diffusion (SFD) to normal diffusion as the channel
diameter reaches a passing threshold where the particles are able to hop past each other. In
this hopping regime, molecular simulations have shown that the long time diffusion
coefficient of the particles can be described in term of a hopping time, defined as the average
time a particle performs SFD before escaping the cage formed by its neighbours. We use a
small system isobaric- isothermal, NPT, ensemble to develop a rigorous Transition State
Theory approach for calculating the hopping time which involves calculating the free energy
barrier associated with two particles attempting to pass. The method is then used to explore
how particle-particle and particle-wall interactions influence diffusion in narrow channels,
including studying the possibility of using the SFD-Normal diffusion crossover regime for the
dynamic separation of mixtures.
Conf-TF-30 ORAL CONTRIBUTIONS
Invited Talk
In-Situ Probing of the Dynamics of Irreversibly Adsorbed
Layers in PVME Thin Films
Sherif Madkour , Andreas Schönhals
Bundesanstalt für Materialforschung und –prüfung (BAM), Unter den Eichen 87, 12205
Berlin, Germany
For many years now, the so-called three layer model (free-surface, bulk-like, and adsorbed
layers) has been commonly used, along with other parameters,[1]
to explain the deviations
seen in glass transition and glassy dynamics for polymers confined into thin films, compared
to their bulk value. Nevertheless, due to the hard accessibility of the adsorbed layers in
supported films, little is known about the nature of their dynamics and how they really
influences the overall dynamics of the thin films. Here, the irreversibly self-assembled
adsorbed layer of a low MW Poly (vinyl methyl ether) (PVME) is solvent-leached from a 200
nm film. The thickness and topography of this layer is checked with Atomic Force
Microscopy (AFM), to insure no dewetting and low roughness. Further, the dynamics of the
adsorbed layer is then in-situ probed with Broadband Dielectric Spectroscopy (BDS). A
recently developed nano-structured capacitor arrangement was employed; where a silicon
wafer with nanostructured SiO2 nano-spacers, with heights of 35 nm, is placed on top of a thin
film spin coated on an ultra-flat highly conductive silicon wafer. All results will be discussed
in detail and quantitatively compared to our recent work [2]
on the glassy dynamics of PVME
thin films (50 nm- 7nm), where BDS measurements showed two thickness-independent
relaxation processes. The first process was assigned to the -relaxation of a bulk-like layer.
Whereas the second process showed a different temperature dependence and was ascribed to
the relaxation of polymer segments adsorbed at the substrate. To our knowledge, this is the
first in-situ study of the dynamics of an irreversibly adsorbed layer.
REFERENCES
1. Napolitano, S.; Glynos, E.; Tito, N. Glass Transition of Polymers in Bulk, Confined Geometries, and Near
Interfaces. Rep. Prog. Phys. 80, 036602 (2017).
2. Madkour, S., Szymoniak, P., Heidari, M., von Klitzing, R., Schönhals, A.. Unveiling the Dynamics of Self-
Assembled Layers of Thin Films of Poly(vinyl methyl ether) (PVME) by Nanosized Relaxation
Spectroscopy. ACS Appl. Mater. Interfaces. 9, 7535-7546 (2017).
ORAL CONTRIBUTIONS Conf-TF-31
Oral
Molecular dynamics in poly(ethylene glycol) derivatives
under nanoscale geometrical confinement
Małgorzata Jasiurkowska-Delaporte1, Wilhelm Kossack
2, Wycliffe K.
Kipnusu3, Joshua R. Sangoro
4, Ciprian Iacob
5, Friedrich Kremer
2
1 The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences,
Radzikowskiego 152, 31-342 Kraków, Poland
2 Institute of Experimental Physics I, University of Leipzig, Linnéstr. 5, Leipzig, Germany
3 Leibniz Institute of Surface Modification, Permoserstr.15, 04318 Leipzig, Germany
4 Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville,
USA
5 Penn State University, Department of Materials Science and Engineering, University Park,
PA 16802 USA
This study investigates molecular dynamics of two glass-forming systems, namely
poly(ethylene glycol) phenyl ether acrylate and poly(ethylene glycol) dibenzoate, confined in
unidirectional, non-intersecting nanopores of mean diameters 4, 6 and 8 nm, probed by a
combination of Broadband Dielectric Spectroscopy (BDS) and Fourier-Transform Infrared
Spectroscopy (FTIR). The intra-molecular mobility is revealed by analyzing the temperature
dependencies of the spectral position as well as intensity of specific IR absorption bands and
compared with intermolecular dynamics obtained by means of dielectric measurements. The
impact of pore sizes on dynamics of individual molecular units is found out. It is
demonstrated that intra-molecular dynamics becomes less sensitive to temperature under
nanoscale confinement. The effect of different end groups i.e. phenyl rings, acrylate
functional group on the dynamics of ethylene glycol chains is also elucidated. The
information obtained in this way gives new insights to the description of the glass transition in
restricted geometry.
Acknowledgements
M. J-D acknowledges the National Science Centre (Grant SONATA11: UMO-
2016/21/D/ST3/01299) for financial suport.
Conf-TF-32 ORAL CONTRIBUTIONS
Invited Talk
Critical behavior of ‘linear’ and ‘nonlinear’ dielectric
properties - the gas-liquid and consolute critical point
puzzles.
Sylwester J. Rzoska and Aleksandra Drozd-Rzoska
Institute of High Pressure Physics Polish Academy of Sciences,
ul. Sokolowska 29/37, 01-142 Warsaw, Poland
The critical consolute point in mixtures of limited miscibility and the gas-liquid critical point
are examples of ‘critical’ systems basing on which the formulation of the physics of critical
phenomena started yet in 19th
century [1,2]. In 1980 it has been finally formed as the unique
category showing clearly universal and system independent behavior of qualitatively different
systems at the microscopic level [3]. Surprisingly, the description of dielectric properties
(both linear and non-linear) appeared for the most classical cases of the gas-liquid and
consolute critical point appeared to be resistive until the nineties – both for experimental and
theoretical insight. Indeed, cognitive problems with these phenomena exists until now.
This contribution presents this fascinating story and shows new results yielding hopes for
solving these long standing puzzles [4-6].
References:
1. Thomas Andrews, The Bakerian Lecture: On the Continuity of the Gaseous and Liquid States of
Matter", Phil. Trans. Royal Soc. London, vol. 159, 575 (1869).
2. J. D. van der Waals, The Nobel Prize (1910): for work on the equation of state for gases and
liquids. http://www.nobelprize.org/nobel_prizes/physics/laureates/1910/waals.
3. K. G. Wilson, The Nobel Prize (1982): for work on renormalization group and critical
phenomena.
https://www.nobelprize.org/nobel_prizes/physics/laureates/1982/wilson-lecture.pdf
4. S. J. Rzoska, Kerr effect and nonlinear dielectric effect on approaching the critical consolute
point, Phys. Rev. E 48, 1136 (1993).
5. S. J. Rzoska, A. Drozd-Rzoska, J. Zioło, Dynamics of critical fluctuations in a binary mixture of
limited miscibility under strong electric field, Phys. Rev. E 61, 960 (2000).
6. A. Drozd-Rzoska and S. J. Rzoska, The super- and sub- critical effects for dielectric constant in
diethyl ether , J. Chem. Phys. 144, 24506 (2016).
7. A. Drozd-Rzoska and S. J. Rzoska, Pretransitional behavior of nonlinear dielectric effect for the
liquid – solid transition in nitrobenzene, Phys. Rev. E, 93, 062131 (2016).
ORAL CONTRIBUTIONS Crys-Amor-GT-1
Invited talk
Key physical factor controlling the glass-forming ability
of systems with competing orderings
Hajime Tanaka1, John Russo
1,2, Flavio Romano
3
1Institute of Industrial Science, University of Tokyo, Tokyo, Japan
2 Department of Mathematics, University of Bristol, Bristol, UK
3Department of Molecular Science, University of Venice, Venice, Italy
When a liquid is cooled below the melting point with a certain cooling rate, it is either crystallized or
vitrified depending upon the rate. However, it has been unclear what physical factors control the ease of
crystallization, or the glass-forming ability. For hard and soft spheres, we found that crystal-like bond
orientational order grows in both size and lifetime when the degree of supercooling is increased [1].
Furthermore, we revealed that such structural order plays a crucial role in crystal nucleation and polymorph
selection [2-5]: In the early stage of crystal nucleation, the ordering proceeds with the enhancement of
spatial coherence of crystal-like bond orientational order and is primarily ‘not’ driven by translational
order. Translational ordering plays a crucial role only in the late stage. This indicates the importance of
pre-ordering of a supercooled liquid, which takes place before crystal nucleation is initiated.
On the basis of this physical picture, we study the glass-forming ability of liquids with competing orderings
[6], where an increase in the glass forming ability is signaled by a depression of the melting temperature
towards its minimum at triple or eutectic points. We find that the enhancement of the glass-forming ability
is caused by an increase in the structural difference between liquid and crystal: stronger competition in
orderings towards the melting point minimum makes a liquid structure more disordered (more complex).
This increase in the liquid-crystal structure difference drives the free-energy barrier for crystallization to
grow rapidly in the glass-forming region. Our finding may provide a general principle for the emergence of
glassy behavior of a system with competing orderings, which we argue is valid whenever there is strong
competition between two or more orderings, including ordering of structural, magnetic, electronic, charge
and dipolar origin.
Our study also indicates that liquid-state theories at the two-body level may not be enough for the
description of the phenomena taking place below the melting point and it is crucial to take into account
many-body correlations [1,7].
REFERENCES
1. Tanaka, H., Eur. Phys. J. E, 35, 113 (2012).
2. Kawasaki, T. and Tanaka, H., Proc. Natl, Acad. Sci. USA 107, 14036 (2010).
3. Russo, J., and Tanaka, H., Sci Rep. 2, 505 (2012); Soft Matter 8, 4206 (2012).
4. Russo, J., and Tanaka, H., MRS Bulletin 41, 369 (2016); J. Chem. Phys. 145, 211801 (2016).
5. Arai, S., and Tanaka, H., Nature Phys. (in press).
6. Russo, J., Romano, F., and Tanaka, H., to be published.
7. Leocmach, M., Russo, J. and Tanaka, H., J. Chem. Phys. 138, 12A536 (2013).
Crys-Amor-GT-2 ORAL CONTRIBUTIONS
Invited Talk
Crystallization vs vitrification tendencies of
model materials: Insights from molecular dynamics
simulations
J. Gerges, L.-C. Valdès and F. Affouard
Unité Matériaux et Transformations (UMET), UMR CNRS 8207,
UFR de physique – BAT P5
Université Lille 1, 59655 Villeneuve d'Ascq France
The natural tendency of a material to crystallize or to vitrify cannot be easily predicted. It is a
fundamental problem in material science with many implications in the pharmaceutical
developments in particular for the formulation of drugs in the amorphous state. The
crystallization occurs in general in two steps of nucleation and growth during which the same
fundamental factors appear: i) the molecular mobility measured for example by the diffusion
or indirectly by the viscosity, ii) the driving force which is the difference in the Gibbs free
energy between the liquid and the crystalline states and iii) the interfacial free energy between
the liquid and the solid. The knowledge of these three parameters coupled with theoretical
approaches like the classical nucleation theory and some growth models (normal, 2d, screw
dislocation) can provide an estimation of the ability of a material to crystallize or not.
In this work, by means of molecular dynamic simulations, we determined the main factors
involved in the nucleation and the growth of different materials. The overlap of the nucleation
and growth zones enabled us to analyze the crystallization tendency of these materials and
especially emphasis the role of the crystal-liquid interfacial free energy. This analysis
particularly allowed us to clarify the unexplained glass-forming ability of some materials and
the preferential crystallization of certain metastable polymorphs.
ACKNOWLEDGEMENTS
This work has received funding from the Interreg 2 Seas programme 2014-2020 co-funded by
the European Regional Development Fund under IMODE project.
REFERENCES
1. Gerges, J., Affouard, F., Predictive Calculation of the Crystallization Tendency of Model Pharmaceuticals
in the Supercooled State from Molecular Dynamics Simulations, The Journal of Physical Chemistry B
119 10768-10783 (2015)
ORAL CONTRIBUTIONS Crys-Amor-GT-3
Invited Talk
Self-Confined Dynamics in supercooled Isopropanol during
crystallization as revealed by quasielastic neutron
scattering methods
A. Sanz1, M. Jiménez-Ruiz
2, A. Nogales
3, I. Šics
4,
T. A. Ezquerra3
1”Glass and Time”, IMFUFA, Roskilde University, DK-4000 Roskilde, Denmark
2Institut Laue-Langevin, BP 156-38042 Grenoble Cedex 9, France.
3Instituto de Estructura de la Materia, IEM-CSIC, Serrano 121, 28006 Madrid, Spain
4CELLS – ALBA, Cerdanyola del Vallès, Barcelona, Spain.
Over the last decades, hydrogen bonding systems have attracted the interest of the scientific
community for its strong implications in a wide a range of molecular properties. Low
molecular weight monohydroxy alcohols are excellent glass formers and their structural and
dynamic properties have been extensively discussed at the crystalline, glassy, supercooled
liquid and ordinary liquid states [1-3]. Isopropyl alcohol (isopropanol can easily form a glass
if cooled fast enough to avoid the crystallization process. The structure, dynamics and the
thermodynamic properties of isopropanol have been widely studied and frequently discussed
in terms of the molecular aggregates formed by the hydrogen bonds [3]. We have studied the
dynamics of isopropanol during crystallization by using quasielastic neutron scattering
methods in real time. In this case, supercooled liquid isopropanol has been subjected to
isothermal annealing above its glass transition temperature. Our results reveal that the time
scale of the isopropanol reorientation dynamics is altered for the late stages of the
crystallization process. We propose the existence of a confinement effect during the
transformation of amorphous isopropanol into its triclinic phase, in this way modifying the
intrinsic nature of the dynamics assessed by quasielastic neutron scattering at the ns timescale,
mainly for low values of the momentum transfer.
REFERENCES
1. Sanz A. et al., Physical Review Letters 107, 025502 (2011).
2. Talon C.et al., Physical Review Letters 88, 4 (2002).
3. Sanz A. et al., Physical Review Letters 93, 4 (2004).
Crys-Amor-GT-4 ORAL CONTRIBUTIONS
Invited Talk
Suppression of crystalline order by competing liquid
structures
Pierre Ronceray 1
and Peter Harrowell2
1Princeton Center for Theoretical Science, Princeton University, Princeton, NJ 08544, USA
2School of Chemistry, University of Sydney, Sydney N.S.W. 2006, Australia
Upon cooling, a molecular liquid will eventually either crystallize, or continuously arrest in a
amorphous state known as a glass. What features of the liquid determine this fate? Why is
crystallization avoided in glass-formers? As the liquid is cooled down, the local arrangements
of its constituent molecules will increasingly correspond to low-energy configurations. It is
likely that the local structure characterizing the crystalline ground state will be found among
these stable arrangements, and one can thus expect that it will accumulate on cooling.
However, other non-crystalline structures can also be stable in the liquid, and compete with
the accumulation of crystalline order. On what conditions can such a competition stabilize the
supercooled liquid to the point of dynamical arrest? We tackle this question using a lattice
model where both the crystalline order and the non-crystalline structures are explicitly
specified in terms of local configuration of binary spins. We show that in order to efficiently
suppress crystallization, the non-crystalline structure should be energetically and entropically
favoured. Importantly, we demonstrate that it must also geometrically antagonize crystalline
order. We quantify this effect in terms of overlap of structures: crystal-''agonist'' structures
with good overlap with the crystal tend to facilitate crystallization, while crystal-antagonist
ones tend to impede it and dramatically increase the crystal nucleation time.
ORAL CONTRIBUTIONS Crys-Amor-GT-5
Invited Talk
Crystallization of Glass-forming Melts:
New Answers to Old Problems
Jürn W. P. Schmelzer
Institute of Physics, University of Rostock, Albert-Einstein-Strasse 23-25, 18059 Rostock,
Germany
One of the basic ingredients of classical nucleation theory (CNT) consists in the appropriate specification
of the work of critical cluster formation in nucleation. In line with Gibbs’ classical method of description of
heterogeneous systems it is supposed in CNT that the bulk properties of the critical clusters are widely
identical to the properties of the evolving macroscopic phases. Following this basic assumption of CNT, in
the first part of the talk general equations and analytical estimates for the dependence of the
thermodynamic driving force of crystallization and the specific interfacial energy melt-crystal of critical
crystal clusters on temperature and pressure are derived directly applicable in the analysis of experimental
data on crystal nucleation and growth. In particular, it is shown that at the Kauzmann temperature,
corresponding to states where the specific entropies of glass-forming melt and crystal coincide, the
thermodynamic driving force has a maximum in dependence on temperature. In addition, similarly to the
mentioned well-known notation of a Kauzmann temperature, the concept of a Kauzmann pressure is
introduced for crystallization induced by variations of pressure. It is shown that the thermodynamic driving
force of crystal nucleation has maxima not only at the Kauzmann temperature but similarly also at the
Kauzmann pressure. Estimates of the magnitude of the thermodynamic driving force of crystallization and
the specific interfacial energy at these states are also given. However, mentioned basic assumption of CNT
supported by Gibbs’ theory – the assumed independence of the properties of critical clusters on the degree
of deviation from equilibrium - is in a variety of cases in conflict with alternative theoretical approaches
like density functional computations, computer simulations, and experimental data. This problem in the
theoretical description can be overcome by generalizing the classical Gibbs’ approach as performed by us
in the last two decades. In the second part of the talk it will be demonstrated how the generalized Gibbs
approach can be applied to the description of crystallization and some principal consequences will be
analyzed in detail.
REFERENCES
1. Schmelzer, J. W. P., and Abyzov, A. S., Crystallization of glass-forming liquids: Thermodynamic driving
force, J. Non-Crystalline Solids 449, 41-49 (2016).
2. Schmelzer, J. W. P. and Abyzov, A. S., Crystallization of glass-forming liquids: Specific surface energy, J.
Chem. Phys. 145, 064512/1-11 (2016).
3. Schmelzer, J. W. P., Abyzov, A. S., and Fokin, V. M., Thermodynamic Aspects of Pressure Induced
Nucleation: Kauzmann Pressure, International Journal Applied Glass Science 7, 474-485 (2016).
4. Schmelzer, J. W. P., Abyzov, A. S., and Fokin, V. M., Crystallization of Glass: What we know, what we
need to know, International Journal Applied Glass Science 7, 253-261 (2016).
Crys-Amor-GT-6 ORAL CONTRIBUTIONS
Invited Talk
The Structural Foundations of Dynamical Heterogeneity
and Ice Nucleation in Supercooled Liquid Water
Martin Fiztner1, Gabriele Cesare Sosso
1, Stephen Cox
2 and
Angelos Michaelides1
1Department of Physics and Astronomy, University College London, Gower Street London
WC1E 6BT, United Kingdom
2Department of Chemistry, University of California, Gilman Hall Berkeley CA 94720-1462,
California, United States of America
The dynamics of supercooled liquid water affects the widest range of phenomena, such as the
solvation of biological matter [1,2], ionic transfer [3] and most prominently the long-standing
problem of the glass transition [4] and the ubiquitous occurrence of ice nucleation [5]. Here,
we characterize by means of atomistic simulations the dynamics of supercooled liquid water,
in terms of connected, spatially extended domains of slow and fast moving water molecules.
We find that the microscopic origin of this heterogeneous dynamics can be traced back to
specific structural properties of the liquid: in particular, local inhomogeneities within the
hydrogen bond network result in stark differences in terms of the populations of n-membered
rings of water molecules between fast and slow moving domains. The latter are characterized
by the abundance of 6-membered hydrogen bonded rings of water molecules, which however
cannot be labeled as ice-like according to order parameters or topological criteria. This
evidence suggests that the nucleation of ice is likely to take place thanks to the re-orientation
of said rings within the slow moving regions of the liquid, thus highlighting the importance of
the dynamics of supercooled liquid phase in the context of crystal nucleation and growth.
REFERENCES
1. Swenson, J., Jansson, H., and Bergman, R. Relaxation Processes in Supercooled Confined Water and
Implications for Protein Dynamics. Phys. Rev. Lett. 96, 247802 (2006).
2. Bellissent-Funel, M.-C. , Hassanali, A., Havenith, M., Henchman, R., Pohl, P., Sterpone, F., van der Spoel,
D., Xu, Y., and Garcia, A.E. Water Determines the Structure and Dynamics of Proteins. Chem. Rev. 116,
7673 (2016).
3. Thompson, W.H. Solvation Dynamics and Proton Transfer in Nanoconfined Liquids. Annual Review of
Physical Chemistry 62, 599 (2011).
4. Velikov, V., Borick, S., and Angell, C.A. The Glass Transition of Water, Based on Hyperquenching
Experiments. Science 294, 2335 (2001). M. Matsumoto, S. Saito, and I. Ohmine, Nature 416, 409 (2002).
5. Sosso, G.C., Chen, J., Cox, S., Fitzner, M., Pedevilla, P., Zen, A. and Michaelides, A. Crystal Nucleation in
Liquids: Open Questions and Future Challenges in Molecular Dynamics Simulations. Chem. Rev. 116,
7078 (2016).
ORAL CONTRIBUTIONS Crys-Amor-GT-7
Invited Talk
Anomalously slow crystal growth of the glass-forming
alloy CuZr
Chunguang Tang1, Peter Harrowell
2
1School of Materials Science and Engineering, University of New South Wales, NSW,
Australia, 2School of Chemistry, University of Sydney, NSW Australia
Our ability to exploit the benefits of metallic glasses depends on identifying alloys of high
glass-forming ability (GFA). So far, the established empirical correlations of GFA are
statistical guides at best and lack a microscopic rationale. Although simulations have the
potential to provide this physical insight into the maximum crystallization rate, crystal
nucleation is often too slow to be observed. In contrast, measuring the growth rate of a planar
crystal surface represents an accessible route to understanding ordering kinetics.
For a first attempt we have used molecular dynamics simulations to show that (ref. 1) the
crystal growth rate for an important binary glass former, CuZr, is significantly slower than
that of a poor glass former, NiAl. In accounting for this difference, we find that the
crystal/liquid interface in NiAl exhibits a significantly greater width than that of CuZr. We
have also extended these studies to the case of free surfaces by studying the crystallization of
liquid slabs interfaced with vacuum. In this case spontaneous crystallization is observed in
NiAl slabs where composition ordering along the surface normal occurs near the surfaces, but
not in CuZr slabs which lacks the surface ordering. Our results suggest that the interfacial
structure between liquid and crystal or vacuum exerts an important influence on the GFA of
alloys.
REFERENCES
1. Tang, C., and Harrowell, P., Anomalously slow crystal growth of the glass-forming alloy CuZr, Nature
Materials. 12, 507-511 (2013).
Crys-Amor-GT-8 ORAL CONTRIBUTIONS
Invited Talk
Controlling frustration in glass forming liquids
Francesco Turci1, Gilles Tarjus
2, and C. Patrick Royall
1,3,4,5
1 H.H. Wills Physics Laboratory, University of Brisol, Tyndall Avenue, Bristol, BS8 1TL, UK
2 LPTMC, CNRS-UMR 7600, Université Pierre et Marie Curie,boîte 121, 4 Pl. Jussieu,
75252 Paris cedex 05, France 3 School of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, UK
4 Centre for Nanoscience and Quantum Information, Tyndall Avenue, Bristol, BS8 1FD, UK
5 Department of Chemical Engineering, Kyoto University, Kyoto 615-8510, Japan
Short-range order plays a salient role in liquids, under the form of specific recurrent and
eventually competing geometrical motifs. Only few of these are compatible with the
formation of a crystalline structure upon freezing: the most common motifs, instead, often
contribute to the frustration of the particle mobility and, if crystallisation is prevented, to the
emergence of glassy dynamics.
Here we study in silico how frustration in supercooled liquids can be controlled and reduced
to favour the formation of ordered phases. We do so following two possible routes: i) slightly
perturbing the curvature of the space the liquids are embedded in1, or ii) slightly modifying
their composition2.
We find that slow dynamics is very robust to both the two kinds of perturbations. In
particular, we observe that while for weak frustration the collective behaviour of the studied
glassforming liquids is governed by the presence of geometric motifs, for large frustration the
dynamical slowing down involves regions much larger than the extent of the geometric
domains, suggesting that additional mechanisms come into play.
REFERENCES
1. Turci F, Tarjus G, and Royall CP From glass formation to icosahedral ordering by curving three-
dimensional space, accepted in Phys. Rev. Lett. (2017)
2. Crowther P, Turci F and Royall CP The nature of geometric frustration in the Kob-Andersen mixture, J.
Chem. Phys. 143 044503 (2015).
ORAL CONTRIBUTIONS Crys-Amor-GT-9
Invited Talk
Glassy dynamics as reflected in its inter- and intra-
molecular interactions
F. Kremer and W. Kossack
Peter Debye Institute for Soft Matter Physics, University of Leipzig, Linnéstr. 5, 04103
Leipzig, Germany
The inter- and intra-molecular interactions of low molecular weight and polymeric glass-
forming model systems are studied by Broadband Dielectric (BDS) - and Fourier-Transform
Infrared (FTIR) - Spectroscopy. Analyzing the temperature dependencies of specific IR
absorption bands, reflecting the intramolecular potentials of dedicated molecular moieties,
enables one to unravel on an intramolecular scale the process of glass formation and to
compare it with the dielectrically determined primarily intermolecular dynamics. Molecular
systems to be studied are typical glassformers as glycerol, propyleneglycol, poly-
propyleneglycol, propylenecarbonate and polypropylencarbonate. By that a wealth of novel
information is obtained proving that the different molecular moieties of a glass former show
often strongly different characteristic, temperature dependencies. This demonstrates the
fundamental importance of intra-molecular dynamics giving refined insights into the
underlying interactions beyond coarse-grained models treating the glassformer as rigid body.
References
1. Papadopoulos, P., Kossack, W. and Kremer F., Intra- and inter-molecular dynamics in glass-forming
liquids, Soft Matter. 9, 1600 (2013).
2. Jasiurkowska, M., Kossack, W., Ene, R., Iacob, C., Kipnusu, W. K., Papadopoulos, P., Sangoro, J. R.,
Massalska-Arodz, M and Kremer, F, Molecular dynamics and morphology in confined 4-heptyl-4-
isothiocyanoatobiphenyl liquid crystals, Soft Matter 8, 5194-5200 (2012).
3. Kaminski, K., Kipnusu, W. K., Adrjanowicz, K., Mapesa, E., Iacob, C., Jasiurkowska, M., Wlodarczyk, P.,
Grzybowska, K., Paluch, M. and Kremer, F., Comparative study on the molecular dynamics of a series of
polypropylene glycols, Macromolecules 46 (5), 1973-1980 (2013).
4. Kipnusu W. K., Kossack, W., Iacob, C., Zeigermann, P., Jasiurkowska, J., Sangoro, J. R., Valiullin, R. and
Kremer, F., The interplay between inter- and intramolecular dynamics in a series of alkylcitrates, Soft
Matter 9, 4681-4686 (2013).
5. Suttner B., Masterthesis, Leipzig, 2014.
6. Popp L., Masterthesis, Leipzig 2015.
Crys-Amor-GT-10 ORAL CONTRIBUTIONS
Invited Talk
Charge glass transition and charge crystallization
in a geometrically frustrated lattice
Fumitaka Kagawa
RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
Liquids normally turn into crystal when slowly cooled, but structural glass is realized under
sufficient rapid cooling. Recently, there is accumulating evidence that similar phenomena can
occur in a charge degree of freedom in condensed matter [1]. In so-called strongly correlated
electron systems, -(ET)2MM’ (SCN)4 [M = Rb/Cs/Tl; M’ = Zn/Co], charge ordering (or
charge crystallization) occurs at low temperatures, but it is kinetically avoided when rapidly
cooled, eventually resulting in a charge-glass state [2-4]. In this presentation, we discuss: (i)
similarities between charge glass and structural glass; (ii) a possible relationship between the
charge-glass forming ability and the geometrical frustration of the lattice; and (iii) a
nonvolatile phase-change-memory function based on the switching between the charge glass
and the charge crystal [5,6].
REFERENCES
1. For a review, see Kagawa, F.and Oike, H., Adv. Mat. DOI: 10.1002/adma.201601979
2. Kagawa, F., et al., Nat. Phys. 9, 419 (2013).
3. Sato, T., Kagawa, F. et al., Phys. Rev. B 89, 121102(R) (2014).
4. Sato, T., Kagawa, F.et al., J. Phys. Soc. Jpn. 83, 083602 (2014).
5. Oike, H., Kagawa, F.et al., Phys. Rev. B 91, 041101(R) (2015).
6. Oike, H., Kagawa, F.et al., Nat. Phys. 12, 62 (2016).
ORAL CONTRIBUTIONS Crys-Amor-GT-11
Invited Talk
Measuring phase transitions in Au based metallic glasses
via fast differential scanning calorimetry
S. Pogatscher
Chair of Nonferrous Metallurgy, Montanuniversitaet Leoben, Franz Josef Str. 18, 8700,
Leoben, Austria
Fast differential scanning calorimeters (FDSC) provide heating and cooling rates of several
104 Ks
-1 and 10
3 Ks
-1, respectively and enables direct insight to in-situ glass formation and the
crystallization of Au based bulk metallic glasses (BMGs). It is shown that critical cooling and
heating rates can be determined. Moreover, complete time-temperature-transformation maps
for BMGs on cooling and on heating can be accesses and insights into the temperature
dependence of crystal growth can be gained [1]. Suitable conditions and influences of FDSC
measurement parameters like sample mass and sensor surface material are discussed [2].
Finally, experimental evidence for an exotic solid-solid transition in an Au based BMG
occurring via metastable melting under strong non-equilibrium conditions, is shown. The
transformation path starting from the amorphous state and evolving to the supercooled liquid,
a metastable crystalline state, a metastable liquid, a more stable crystalline state and finally
the equilibrium liquid is discussed under its thermodynamic and kinetic prerequisites [3].
REFERENCES
1. Pogatscher, S., Uggowitzer, P. J. & Löffler, J. F. In-situ probing of metallic glass formation and
crystallization upon heating and cooling via fast differential scanning calorimetry. Applied Physics Letters
104 (2014).
2. Pogatscher, S., Leutenegger, D., Hagmann, A., Uggowitzer, P. J. & Löffler, J. F. Characterization of bulk
metallic glasses via fast differential scanning calorimetry. Thermochimica Acta 590, 84-90 (2014).
3. Pogatscher, S., Leutenegger, D., Schawe, J. E. K., Uggowitzer, P. J. & Löffler, J. F. Solid-solid phase
transitions via melting in metals. Nature Communications 7 (2016).
Crys-Amor-GT-12 ORAL CONTRIBUTIONS
Invited Talk
Chip Calorimetric Studies on the Glass Transition and the
De-mixing Dynamics of Polymers
Dongshan Zhou1,2
, Shaochuan Luo1, Evgeny Zhuravlev
1,3, Gi Xue
1
1Department of Polymer Science and Engineering, School of Chemistry and Chemical
Engineering, Nanjing University, Nanjing 210093
2Shenzhen R.&D. Center, State Key Laboratory of Coordination Chemistry, Nanjing
University, Shenzhen 518057
3Institute of Physics, Rostock University, Rostock 18051
The devitrification behavior of supported polystyrene (PS) thin films after different
cooling processes was investigated by the alternating current (AC) chip calorimeter. For low
molecular weight and star-shaped PS films, besides the thickness dependence that we have
reported before, we can clearly find that the higher the cooling rates, the lower the Tg. We
also find that the cooling rate variation caused Tg shift becomes faster for thinner films. When
capped by a poly(methyl methacrylate) (PMMA) layer, the cooling rate dependence of Tg is
less pronounced for oligomer ultrathin films. We attribute it due to the obstruction of the
elimination of free volume by the additional interface between PS and PMMA ultrathin films.
Taking poly(vinyl methyl ether)/polystyrene (PVME/PS) blend as the example,
Ultrafast differential scanning calorimetry (UFDSC) is used to study the de-mixing dynamics.
By the virtue of small time and spatial resolution that UFDSC offers, the time dependence of
the Tg of PVME-rich phase, shows a distinct change when the annealing temperature (Ta)
changes from below to above 385 K. This corresponds to the transition from the nucleation
and growth (NG) mechanism to the spinodal decomposition (SD) mechanism, as was verified
by morphological and rheometric investigations.
ORAL CONTRIBUTIONS Crys-Amor-GT-13
Invited Talk
Interplay between the Relaxation of the Glass of Random
L/D Lactide Copolymers and Homogeneous Crystal
Nucleation: Evidence for Segregation of Chain Defects
Rene Androsch1 and Christoph Schick
2,3
1 Center of Engineering Sciences, Martin Luther University Halle-Wittenberg, 06099
Halle/Saale, Germany
2 Institute of Physics and Competence Centre CALOR, University of Rostock, Albert-
Einstein-Str. 23-24, 18051 Rostock, Germany
3 Kazan Federal University, 18 Kremlyovskaya street, Kazan 420008, Russian Federation
Random L isomer rich copolymers of poly(lactic acid) containing up to 4% D isomer co units
have been cooled from the molten state to obtain glasses free of crystals and homogeneous
crystal nuclei. The kinetics of enthalpy relaxation and the formation of homogeneous crystal
nuclei have then been analyzed using fast scanning chip calorimetry. It has been found that
the relaxation of the glass toward the structure/enthalpy of the supercooled liquid state is
independent of the presence of D isomer co units in the chain. Formation of homogeneous
crystal nuclei in the glassy state requires the completion of the relaxation of the glass.
However, nucleation is increasingly delayed in the random copolymers with increasing D
isomer chain defect concentration. The data show that the slower formation of homogeneous
crystal nuclei in random L/D lactide copolymers, compared to the homopolymer, is not
caused by different chain segment mobility in the glassy state but by the segregation of chain
defects in this early stage of the crystallization process.
REFERENCES
1. Androsch, R. and Schick, C., Interplay between the Relaxation of the Glass of Random l/d-Lactide
Copolymers and Homogeneous Crystal Nucleation: Evidence for Segregation of Chain Defects, J. Phys.
Chem. B 120 4522-4528 (2016)
Crys-Amor-GT-14 ORAL CONTRIBUTIONS
Invited Talk
Studying Crystallization on Increased Pressure -
Compression Rate and Thermodynamic Path Dependence
Karolina Adrjanowicz1,2
, Grzegorz Szklarz1,2
, Kajetan Koperwas1,2
and
Marian Paluch1,2
1 Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland
2 Silesian Center for Education and Interdisciplinary Research, University of Silesia, 75 Pulku
Piechoty 1A, 41-500 Chorzow, Poland
The physical and chemical properties of matter may drastically change when subjected to
high pressure. Among these, pressure-induced changes in the crystallization behavior of
various materials are of great scientific and technological import. As revealed by numerous
experimental studies, crystallization at increased pressure can be quite different from that
observed when cooling liquid at atmospheric pressure. The difference arises from the fact that
temperature and pressure are not equivalent thermodynamic variables, although both produce
superficially similar effects. Therefore, both are needed to get a complete understanding of
crystallization and vitrification phenomena.
The motivation for the present study was to examine crystallization tendencies of molecular
liquids at varying thermodynamic conditions. To do that we have carefully investigated the
effect of path and compression rate dependence on crystallization. Tested samples were van
der Waals liquids. We show (i) that the direction of moving in the phase diagram to reach
final (T, p) conditions affects the crystallization outcome, especially its initial stages related
with the nucleation process, and (ii) crystallization progress at varying pressure can be
analyzed in terms of Continuous-Compression-Transformation and Continuous-
Decompression-Transformation diagrams, termed in analogy to CCT (Continuous-Cooling-
Transformation) and CHT (Continuous-Heating-Transformation) diagrams, which are a very
useful way of analyzing non-isothermal processes as a function of the cooling/heating rate.
Thus, by taking the advantages of both features, we can tune the crystallization tendency of
molecular liquids with the use of increased pressure.
ORAL CONTRIBUTIONS Crys-Amor-GT-15
Invited Talk
Glass Forming Ability and Stability in Phase Change
Materials
Martin Salinga
IBM Research Zurich, Säumerstrasse 4, 8803 Zürich, Switzerland
In phase change memories - arguably the most mature of all emerging memory technologies -
information is stored by utilizing the pronounced contrast in electrical resistivity between
crystalline and amorphous states of materials often referred to as ‘phase change materials’.
While amorphous states are stable against crystallization for many years at temperatures
below 100°C, a rapid phase transition can take place in nanoseconds when electrical pulses
induce Joule-heating to a temperature regime of high atomic mobility.
This characteristic feature of this family of materials has both formed the foundation of its
success in memory applications and at the same time drawn persistent interest in its
fundamental physical processes.
Due to their tendency to crystallize very quickly, these materials can only form a glass when
quenched from the melt at extremely fast rates. As a consequence, systematic studies of the
crystallization kinetics as a function of temperature have commonly been limited to the
investigation of crystallization of (the much more easily created) as-deposited amorphous
states. However, in the last years, experimental evidence for crystallization has also been
achieved from melt-quenched states.
In this presentation the crystallization of phase change materials will be discussed on the basis
of recent findings including Ab-initio Molecular Dynamics simulations. The discussion of the
underlying mechanisms will involve the pronounced deviations from an Arrhenius-like
temperature dependence of the viscosity, extraordinarily high fragilities, break-down of the
Stokes-Einstein relation, dynamical heterogeneity, fragile-to-strong transition in the
supercooled liquid, and the influence of quenching/heating rates.
Secondly, the finite stability of the amorphous states of phase change materials has impeded
multiple-bits-per-cell schemes for phase change memories. The phenomenon of drifting
amorphous resistivity will be analyzed and possible solutions will be examined.
Finally, novel circuit elements for neuromorphic electronics will be proposed with
functionalities based on the changing electrical properties of the glass states of phase change
materials.
Crys-Amor-GT-16 ORAL CONTRIBUTIONS
Invited Talk
Crystallization vs amorphization in water and hard spheres
J. R. Espinosa1, P. Rosales-Pelaez
1, A. Zaragoza
1, C. Navarro
1, J. L. F.
Abascal1, C. Vega
1, C. Valeriani
2 E. Zaccarelli
3, W. C. K. Poon
4, M. E.
Cates4, P. N. Pusey
4, E. Sanz
1
1Dep. Quimica-fisica I, UCM, 28040, Madrid, Spain,
2 Dep. Fisica Aplicada I, UCM, 28040, Madrid, Spain,
3 CNR-ISC and Dipartimento di Fisica, Universita di Roma La Sapienza, P.le A. Moro 2,
00185 Roma, Italy 4 SUPA, School of Physics and Astronomy, University of Edinburgh, Mayfield Road,
Edinburgh, EH9 3JZ, Scotland
The competition between crystallization and amorphization in water is key in the
cryopreservation of biological samples [1], where the formation of ice has to be averted upon
cooling given its deleterious effect for the cells. A strategy to decelerate the formation of ice
in cryopreservation protocols is to put the sample under hydrostatic pressure [2]. We use
computer simulations to investigate the effect of pressure on water freezing. Simulations is a
particularly suitable tool to study ice nucleation because it enables access to the time and
length scales relevant to ice nucleation, ns and nm, complementing the information obtained
in experiments where such small scales can not be probed. We find that pressure slows down
ice nucleation mainly by increasing the ice-water interfacial free energy [3]. We discuss
possible strategies that can be used to beat ice nucleation on cooling.
Even if crystallization is averted and a glass is eventually formed, the battle between
amorphization and crystallization is not over. Despite the absence of molecular diffusion a
glass can crystallize in a process called devitrification. Such process is undesirable not only in
cryopreservation, but also when glasses are used as materials given that crystallization can
alter its properties. We use hard spheres, arguably the simplest system showing fluid, crystal
and glass phases, to investigate the mechanism by which glasses devitrify with computer
simulations. We find that crystallization is caused by stochastic, intermittent, cooperative
particle motions that we call avalanches[4].
References
1. Morris, G.J, Acton, E., Controlled ice nucleation in cryopreservation-a review, Cryobiology. 66, 85 (2013).
2. Kanno, H., Speedy, R.J., Angell, C.A., Supercooling of water to -92? under pressure, Science. 189, 880
(1975).
3. Espinosa, J. R., Zaragoza, A., Rosales-Pelaez, P., Navarro, C., Valeriani, C., Vega, C., Sanz, E., Interfacial
free energy as the key to the pressure-induced deceleration of ice nucleation, Phys. Rev. Lett., 117, 135702,
(2016).
4. Sanz, E., Valeriani, C., Zaccarelli, E., Poon, W. C. K., Cates, M. E. & Pusey, P. N., Avalanches mediate
crystallization in a hard-sphere glass. PNAS 111, 750 (2014).
ORAL CONTRIBUTIONS Crys-Amor-GT-17
Oral
Polymer crystallization at large supercooling, studied by
modified Fast Scanning Calorimetry
Evgeny Zhuravlev1,2
, Jing Jiang1, Dongshan Zhou
1,3, Christoph Schick
2,
Gi Xue1
1Department of Polymer Science and Engineering, School of Chemistry and
Chemical Engineering, Nanjing University, Nanjing 210093
2Institute of Physics, Rostock University, Rostock 18051
3Shenzhen R.&D. Center, State Key Laboratory of Coordination Chemistry, Nanjing
University, Shenzhen 518057
Polymer crystallization in the vicinity of glass transition still remains the point of large controversy
[1]. Time and size of the involved rearrangements places certain challenge for instrumentation and
experimental design. Fast Scanning Calorimetry (FSC) introduced by [2] brought vast possibilities for
polymer vitrification and crystallization study. It can follow up crystallization/vitrification at cooling
rates up to 1,000,000 K/s under condition of liquid nitrogen cooled gas environment. Separation of
heat treatment and analysis temperature scans gives even more opportunities e.g. for crystal nucleation
rate measurement [3]. But calorimetry on it’s own can’t provide all parameters, required for
crystallization analytical description or modeling. Such as number and size of a crystal/nuclei.
Combination of structural technique is vitally important. Because most of the technique are unable to
reach the rate of cooling offered by FSC, multi-stage experiment design becomes useful. Precisely
ordered material shall be frozen, or allowed to develop at different temperature for determination of
needed parameters under AFM or optical microscopy. Combination of FSC, AFM and optical
microscopy was used to follow homogeneous nucleation of PBT.
Multi-stage FSC experiments includes ultra-fast heating and cooling steps, virtually avoiding any
possible reorganization. At the same time, liquid nitrogen cooled atmosphere benefit of the FSC
restricts it’s usage with AFM. A solution significantly improving cooling performance of FSC close to
room temperature is suggested and realized for polyethylene crystallization study (see poster session
for details).
REFERENCES
1. Androsch, R., E. Zhuravlev, and C. Schick, Solid-state reorganization, melting and melt-recrystallization of
conformationally disordered crystals (α′-phase) of poly (l-lactic acid). Polymer,. 55: p. 4932-4941 (2014).
2. Zhuravlev, E. and C. Schick, Fast scanning power compensated differential scanning nano-calorimeter: 2.
Heat capacity analysis. Thermochimica Acta,. 505(1-2): p. 14-21 (2010).
3. Zhuravlev, E., et al., Experimental test of Tammann’s nuclei development approach in crystallization of
macromolecules. Crystal Growth & Design,. 15(2): p. 786-798 (2015).
Crys-Amor-GT-18 ORAL CONTRIBUTIONS
Oral
Investigations of physical properties of amorphous
materials obtained from different routes
F. Ngono1,2
, F. Affouard1, J.F. Willart
1, G. J. Cuello
2, M. Jimenez-Ruiz
2
1 Université Lille Nord de France, Unité Matériaux et Transformations, UMR CNRS 8207,
Av. Paul Langevin, F-59655 Villeneuve d'Ascq, France
2 Institut Laue Langevin, 71 Av. des Martyrs, CS 20156, F-38042, Grenoble, France
So far, substances of pharmacy (active pharmaceutical ingredients and excipients) are most
often prepared in the crystalline state (ordered) for obvious reasons of stability. Many
pharmaceuticals, either by accident or design, may also exist in a total or partially amorphous
state (disordered). This situation is encountered more and more frequently due to the
increasing complexity of synthesized molecules. The amorphous state has a lower stability
but a higher solubility than the corresponding crystalline forms. The formulation of active
substances in the amorphous state, has thus motivated a strong interest in the last decade to
increase the solubility of poorly soluble drugs[1]
.
In this study, the amorphisation process and the amorphous state of lactulose (C12H22O11), a
disaccharide of pharmaceutical interest, have been investigated by combining a wide range of
experimental and numerical techniques in order to probe structural, dynamical and
thermodynamical physical properties. The amorphisation process resulting from milling of a
crystalline sample was particularly analysed. The amorphous compounds obtained by milling
were compared to other amorphous forms designed by alternative amorphisation routes such
as melt-quenching, freeze-drying, spray-drying[2]
. Recently, neutron diffraction with
polarization analysis has been developed on D3 and successfully applied to mixtures of light
and heavy water [ L. Temleitner et al., Phys. Rev. B (2015)]. For the first time, we were able
to experimentally obtain the coherent structure factor of highly hydrogenated lactulose
samples using D3 and D7 neutron diffractometers available at ILL. In addition, differences
between the amorphous samples due to thermal degradations and chemical changes have been
clarified aiming to unravel the true impact of the amorphisation mechanism itself.
REFERENCES
1. Johari, G. P. and Shanker, R. M., On the solubility advantage of a pharmaceutical’s glassy state over the
crystal state, and of its crystal polymorphs, Thermochimica Acta 598, 16 (2014)
2. Willart, J. F. and Descamps, M., Solid State Amorphization of Pharmaceuticals, Molecular Pharmaceutics 5,
905 (2008)
3. Temleitner, L. et al., Neutron diffraction of hydrogenous materials: Measuring incoherent and coherent
intensities separately, Phys. Rev. B (2015)
ORAL CONTRIBUTIONS Crys-Amor-GT-19
Invited Talk
Phase Change Materials by Design:
The Mystery of Resonance Bonding
Matthias Wuttig
RWTH Aachen University of Technology, Germany
JARA Institute Green-IT, RWTH Aachen and Forschungszentrum Jülich, Germany
Phase change media utilize a remarkable property portfolio including the ability to rapidly
switch between the amorphous and crystalline state, which differ significantly in their
properties. This material combination makes them very attractive for data storage applications
in rewriteable optical data storage, where the pronounced difference of optical properties
between the amorphous and crystalline state is used. This unconventional class of materials is
also the basis of a storage concept to replace flash memory. This talk will discuss the unique
material properties, which characterize phase change materials. In particular, we will focus on
the pronounced differences between the amorphous and crystalline state in terms of atomic
arrangement and physical properties. This pronounced property and structure difference
distinguishes this material class from ‘ordinary’ Zachariasen glasses. It will be shown that
only a rather small group of materials utilizes resonant bonding, a particular flavour of
covalent bonding, which can explain many of the characteristic features of phase change
materials. This insight is employed to predict systematic property trends and to explore the
limits in stoichiometry for such memory applications. It will be demonstrated how this
concept can be used to tailor the electrical and thermal conductivity of phase change
materials. Yet, the discoveries presented here also force us to revisit the concept of resonance
bonding and bring back a history of vivid scientific disputes about ‘the nature of the chemical
bond’.
Crys-Amor-GT-20 ORAL CONTRIBUTIONS
Invited talk
Clarifying the Origin of Multiple Melting of Segmented
Thermoplastic Polyurethanes by Fast Scanning Calorimetry
J. Balko1, B. Fernández-d’ Arlas
2, E. Pöselt
3, R. Dabbous
4, A. J. Müller
2,
T. Thurn-Albrecht1
1Institute of Physics, Martin Luther University, 06120 Halle/Saale, Germany
2POLYMAT Polymer Science and Technology Department, University of the Basque
Country, 20018, San Sebastián, Spain
3BASF-Polyurethanes GmbH, 49448 Lemförde, Germany
4BASF Schweiz AG, 4058 Basel, Switzerland
Segmented thermoplastic polyurethanes (TPU) often show multiple endothermic signals
during melting in conventional differential scanning calorimetry. Repeated reorganization
during heating as well as separate crystal melting and phase mixing have been proposed as the
origin of this phenomenon. We used fast scanning calorimetry on a series of TPUs with
polyether soft segments and hard segments consisting of 4,4’-methylene-diphenyl
diisocyanate and 1,4-butanediol to differentiate between the two possibilities. Heating scans
of isothermally crystallized samples exhibited only a single melting peak, while
complementary experiments on quenched, fully amorphous samples showed a single glass
transition step indicating a homogeneous mixed phase. These results prove that the multiple
melting peaks observed in DSC are related to reorganization during heating, i.e. repeated
melting and recrystallization. Phase separation during cooling is induced by crystallization. A
comparison with conventional DSC scans shows the consistency of both calorimetric
techniques in the limit of low heating rates.
ORAL CONTRIBUTIONS Crys-Amor-GT-21
Oral
The Attractive Intermolecular Forces and The
Crystallization of the Van Der Walls Liquids
K. Koperwas1,2
, K. Adrjanowicz1,2
, F. Affouard3, J. Gerges
3, L.-C. Valdes
3,
Ż. Wojnarowska1,2
, J. Knapik1,2
, A. Jędrzejowska1,2
, and M. Paluch1,2
1 Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland
2 Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1a, 41-500
Chorzów, Poland
3 Unité Matériaux et Transformations (UMET), UMR CNRS 8207, UFR de Physique, BAT
P5, Université de Lille 1, 59655 Villeneuve d’ascq, France
From the fundamental point of view, the shape of molecules, their masses, and interaction
potential determine the thermodynamics, dynamics and structural properties of any kinds of
the real substances. Consequently, the forces occurring between molecules also decide on the
crystallization tendency and the glass forming ability of a given material. At first glance, the
increase in the attractive intermolecular interactions should cause the decrease in glass
forming ability and makes that system should crystalize easier. However, our very last
experimental and theoretical studies reveal completely contrarybehavior1.
We want to present that the systems, which are characterized by stronger molecular attraction,
easier omit the crystallization, and hence they are better glass formers. Our results indicate
that the strength of the attractive forces affects the location of the nucleation and crystal
growth rate maxima with respect to each other and the melting point. Moreover, basing on the
results obtained from computer simulations of the molecular dynamics of Lennard-Jones like
systems, we demonstrate that increase in pressure causes gain in crystallization tendency
independently on the strength of molecular attraction. However, the system characterized by
weaker attractive forces occurring between molecules are more sensitive to pressure changes,
which is due to significant pressure influence on their interfacial free energy. Subsequently,
considering the origin of the attractive intermolecular forces, which among others result from
interactions between dipole moments of the molecules, we would like to present how the
spatial orientation of the dipole moment (in relation to the selected axis of the molecule)
influence on the glass forming ability of the substance.
REFERENCES
1. Koperwas, K., Adrjanowicz,K., Wojnarowska, Z., Jedrzejowska, A., Knapik, J., Paluch, M., Glass-
Forming Tendency of Molecular Liquids and the Strength of the Intermolecular Attractions, Sci. Rep. 6,
36934.1-10 (2016).
Crys-Amor-GT-22 ORAL CONTRIBUTIONS
Invited Talk
Glass-Forming Metal-Organic Framework
Yuanzheng Yue
State Key Laboratory of Silicate Materials for Architectures, Wuhan University of
Technology, Wuhan 430070, China
Department of Chemistry and Bioscience, Aalborg University, DK-9220 Aalborg, Denmark
E-mail: [email protected]
Metal-organic framework (MOF) glasses are a completely new family of melt-quenched
(MQ) glasses.1-3
These glasses have a high potential to be applied in many occasions such as
gas separation, gas storage, functional films, etc. However, to realize these applications,
several scientific and technological challenges must be addressed. One of those is to
understand the formation and recrystallization mechanism of MOF glasses. If a MOF glass
can recrystallize, it is then possible to create the microporous structure in the glass, which is
of technological interest, e.g., for gas storage application. If the glass does not crystallize, its
high optical transparency could be used for optical and photonic applications. Here, we
review our recent progress in understanding the behavior of melting, glass formation,
relaxation and nano-crystallization of MOFs by taking ZIF-4 and -62 as examples, and
thereby illustrate some universal features of MOF glasses. We show that nanocrystallization
could occur in ZIF-4 upon heat-treatment between glass transition temperature (Tg) and
melting point (Tm), whereas ZIF-62 does not show this behavior. By combining both sub-Tg
and above-Tg annealing experiments with structural analysis, we demonstrate our current
understanding of the dependence of the glass forming ability of MOFs on their chemical
composition and structural heterogeneity. We provide insights into both primary and
secondary relaxation behaviours in MOF glasses. Finally, we suggest some possible ways to
establish the structural and topological criteria for MOF melting and glass formation.
REFERENCES
1. Bennett, T.D., Tan, J.C., Yue, Y.Z. et al., Hybrid glasses from strong and fragile metal-organic framework
liquids, Nature Commun. 6, 8079 (2015).
2. Bennett, T.D., Yue, Y.Z., Li, P., et al., Melt-quenched glasses of metal-organic frameworks, J. Am. Chem.
Soc. 138, 3484- 3492 (2016).
3. Tao, H.Z., Bennett, T.D., Yue, Y.Z., Melt-Quenched Hybrid Glasses from Metal-organic Frameworks, Adv.
Mater. 29, 1601705 (2017).
ORAL CONTRIBUTIONS Dyn-Biomol-1
Invited Talk
Neutron scattering exploration of protein dynamics:
strengths and pitfalls
Ferenc Mezei
European Spallation Source ERIC, PO BOX 176, 22100 Lund, Sweden, and
Wigner Research Center for Physics, Pf. 49, Budapest 1525, Hungary
Neutron scattering is a powerful tool for the investigation of basic functional properties of
proteins [1]. On the one hand, it allows us to explore the motion of atoms which are crucial
for the functionality of proteins. On the other hand, due to their high neutron scattering cross
section, hydrogen atoms can be particularly sensitively observed by neutrons with little
interference by the other atoms in the sample. The incoherent character of neutron scattering
on hydrogen atoms restricts the information obtained to the self-correlations in the motion of
individual hydrogen atoms, simplifying at the same time the interpretation of the data. The
mean square displacement (MSD) is a fundamental parameter for the characterization of the
motion of single atoms, in particular by its variation with the time over which the
displacements are followed. In neutron scattering experiments the quasi-elastic resolution
allows us to specify and vary over a large domain the effective time scale of the observation
of atomic motion. Examination of the dependence of MSD on the time over which the “mean
value” is defined as an average is a very sensitive control for the interpretation. MSD values
obtained at a single averaging time (resolution) are quite often misinterpreted, and eventually
confused e.g. with simple single particle diffusion. The different types of neutron scattering
experiments allow us to cover in the process some 5 orders of magnitude in time, offering
both control of the interpretation and hints to specific dynamic features, including
heterogeneity. Experiments with broad dynamic range exceeding 2 – 3 orders of magnitude in
time / energy can provide meaningful line shapes for benchmarking consistency with model
calculations. The talk gives a technical overview of the different types of experimental
situations and the information elastic and / or quasi-elastic neutron scattering approaches can
make available, illustrated by a few key examples.
REFERENCES
1. Magazù, S., Mezei, F., Falus, P., Farago, B., Mamontov, E., Russina, M.and Migliardo, F., Protein
dynamics as seen by (quasi) elastic neutron scattering, Biochimica et Biophysica Acta 1861, 3504–3512
(2017)
Dyn-Biomol-2 ORAL CONTRIBUTIONS
Invited Talk
Complex collective dynamics of lipid bilayers in the gel and
liquid phases.
Giovanna D’Angelo,1 Valeria Conti Nibali,
1 Ulderico Wanderlingh,
1 Alessio
De Francesco,3 Caterina Branca,
1 Cristina Crupi,
1 Francesco Sacchetti,
2
Caterina Petrillo,2
and Alessandro Paciaroni2
1 Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Messina, Messina,
Italy
2Dipartimento di Fisica e Geologia, Università degli Studi di Perugia, Perugia, Italy
3Consiglio Nazionale delle Ricerche, Istituto Officina dei Materiali,
Operative Group in Grenoble (OGG), Grenoble, France
The collective dynamics of 1,2-dimyristoyl-sn-glycero-3-phoshatidylcholine (DMPC)
bilayers in the gel and liquid phases has been investigated by Brillouin neutron scattering
spectroscopy. The measured spectra are combined with recent Brillouin X-ray spectroscopy
data and interpreted with an extended model based on three interacting modes, for both the
gel and liquid phase. This integrated approach allows for a comprehensive and unprecedented
picture of the vibrational collective features of phospholipid membranes. In the low-Q range,
the dispersion relations, can be interpreted in terms of two acoustic, longitudinal and
transverse, modes plus a dispersionless optic-like mode. A phonon gap for the transverse
mode is found when lipids undergo the gel-liquid transition. At higher Q values, the
interaction of the longitudinal acoustic mode with the dispersionless one gives rise to a pattern
that is consistent with avoided-crossing behavior. The evidence is found for a slow- to fast-
sound transition, in analogy with bulk water and other biological systems.
ORAL CONTRIBUTIONS Dyn-Biomol-3
Invited Talk
Protein dynamics in solvent-free protein-polymer
nanohybrids
Giorgio Schirò1, Yann Fichou
2, Wiebke Lohstroh
3, Gerald Schneider
3,
Michaela Zamponi3, Adam Perriman
4, and Martin Weik
1
1Institut de Biologie Structurale, Grenoble (France);
2University of California Santa Barbara
(USA); 3Heinz Maier-Leibnitz FRM II (Germany);
4University of Bristol (UK)
The ensemble of interactions that stabilize protein native structure and promote protein
functional motions are intimately linked with the ubiquitous aqueous environment of living
systems. As a consequence, biomolecular activity is highly sensitive to the interplay of water-
protein interactions. The use of protein perdeuteration, neutron scattering and molecular
dynamics simulations enabled us to look at the water matrix dynamics around both globular
and intrinsically disordered proteins and to reveal the nature of water motions triggering the
onset of functional protein dynamics [1]. However, the recent realization of solvent-free
protein-polymer nanohybrids with retained functional [2] and dynamical [3] properties
presents novel challenges to existing understanding on the role of solvent molecules in
structural biology, and offers new opportunities in protein-based nanoscience and
bionanotechnology [4]. Here we show how quasi-elastic and inelastic neutron scattering on
selectively perdeuterated protein/polymers hybrids, combined with molecular dynamics
simulation, provides a physical understanding of the functional and dynamical behavior of
such solvent-free systems and indicates the physical parameters of polymer dynamics needed
to mimic a water-like behaviour [5].
References
1. Schirò, G., et al., Translational diffusion of hydration water correlates with functional motions in folded
and intrinsically disordered proteins, Nature Commun. 6, 6490 (2015).
2. Perriman, A. W., et al., Reversible dioxygen binding in solvent-free liquid myoglobin, Nature Chem. 2, 622
(2010).
3. Gallat, F.-X., et al., A polymer surfactant corona dynamically replaces water in solvent-free protein liquids
and ensures macromolecular flexibility and activity, J. Am. Chem. Soc. 134, 13168 (2012).
4. Perriman, A. W., et al., Liquid Proteins - A New Frontier for Biomolecule-Based Nanoscience, ACS Nano
5, 6085 (2011).
5. Schirò, G., Fichou, Y., Perriman, A. W., Weik, M., et al., (in preparation.)
Dyn-Biomol-4 ORAL CONTRIBUTIONS
Invited Talk
Broadband Dielectric Spectroscopy from MHz to THz on
Proteins; Comparison between Globular Proteins and
Membrane Proteins
Naoki Yamamoto1, Shota Ito
2, Kaoru Ohta
3, Eri Chatani
1, Hideki Kandori
2,4,
and Keisuke Tominaga1,3
1: Graduate School of Science, Kobe Univeristy,
2: Department of Life Science and Applied Chemistry, Naogya Institute of Technology,
3: Moleuclar Photoscience Research Center, Kobe University, Nada, Kobe, 657-8501 Japan,
4: OptoBio Technology Research Center, Nagoya Institute of Technology, Gokiso-cho,
Showa-ku, Nagoya, Aichi, 466-8555 Japan
Recently we reported a dielectric spectral study of lysozyme in a solid state to show the
effects of hydration and thermal excitation on the low-frequency dynamics of protein.1
Dielectric measurements were performed under changing hydration conditions at room
temperature in the frequency region of 0.5 GHz to 1.8 THz. We also studied the temperature
dependence (83 K to 293 K) of the complex dielectric spectra in the THz frequency region
(0.3 THz to 1.8 THz). To reproduce the spectra, we found that two relaxational modes and
two underdamped modes are necessary in the model function. At room temperature, the two
relaxational modes have relaxation times of ~20 ps and ~100 ps. The faster component has a
major spectral intensity and is suggested to be due to coupled water-protein motion. We
observed a protein-dynamical-transition-like behavior in the temperature dependence of the
absorption spectra of protein in the THz region. From our broadband measurements, we
conclude that the increase in the spectral intensities in the THz region at approximately 200 K
is due to a spectral blue-shift of the relaxational mode. In this report, we present results of the
broadband dielectric measurements on bacteriorhodopsin, one of the membrane proteins, to
discuss the effects of hydration and thermal excitation on its low-frequency dynamics. We
especially focus on the temperature hysteresis of the spectral intensity, which is related to the
supercooled water around the protein. We compare this hysteresis between the globular
proteins and bacteriorhodopsin.2
REFERENCES
1. Yamamoto, N., et al., “Broadband Dielectric Spectroscopy on Lysozyme in the sub-Gigahertz to Terahertz
Frequency Regions: Effects of Hydration and Thermal Excitation”, J. Phys. Chem. B, 120 (21), pp 4743–
4755 (2016).
2. Kawaguchi, S., et al., “Low-Frequency Dynamics of Bacteriorhodopsin Studied by Terahertz Time-Domain
Spectroscopy”, Phys. Chem. Chem. Phys. 12, 35, 10255 (2010).
ORAL CONTRIBUTIONS Dyn-Biomol-5
Invited Talk
Fast rearrangment dynamics of water in the protein
hydration shell: The view from Extended Depolarized Light
Scattering experiments
Lucia Comeza, Marco Paolantoni
b, Silvia Corezzi
c, Stefania Perticaroli
d,
Paola Sassib, Assunta Morresi
b, Daniele Fioretto
c
aCNR-IOM, c/o Dipartimento di Fisica e Geologia, Via Pascoli, I-06123 Perugia, Italy
bDipartimento di Chimica, Biologia e Biotecnologie Università di Perugia, Perugia, Italy
cDipartimento di Fisica e Geologia, Università di Perugia, Via Pascoli, I-06123 Perugia, Italy
dOak Ridge Natl Lab, Shull Wollan Ctr, Oak Ridge, TN 37831 USA, USA
The hydration dynamics of the model protein lysozyme in water-rich aqueous solutions has been investigated by
Extended Depolarized Light Scattering (EDLS) experiments at different concentrations and temperatures [1,2]. This
technique has proved to be suitable for the study of dynamical processes in the broad frequency range going from
fractions of GHz to tens of THz, corresponding to molecular dynamics on a time scale ranging from fractions to
hundreds of picoseconds [3-7]. A detailed analysis of the EDLS spectral profiles provides evidence of the existence of
two distinct relaxation processes on a picosecond time scale ascribed to hydration and bulk water. Under the influence
of the protein, the dynamics of water is found to slow down by a factor 7-8, with a characteristic relaxation time going
from ca. 0.6 ps for bulk water to ca. 4-5 ps for hydrating water molecules [1,4,7]. This retardation accounts for the
effect induced by the protein on the local density fluctuations of water, which are basically related to the fast
rearrangement of hydrogen bonds within the shell. It has been estimated that, in diluted conditions, this perturbation
extends over large distances (>10 Å) from the protein surface, affecting the dynamics of more than three water layers.
Moreover, our experiments evidence a strong reduction of the population of perturbed water with the increasing of
lysozyme concentration. This behavior cannot be explained considering the random superposition among the solute
hydration layers, but is instead consistent with the formation of protein clusters [2,7]. The overall picture has been
confirmed by comparative EDLS investigation performed using deuterated water as solvent. Interestingly, these
experiments reveal a non-negligible isotopic effect on the retardation dynamics. Indeed, passing from light to
deuterated water, a relatively greater slowing down effect is found. On the other hand, the spatial extent of the
perturbation is found to be comparable for both solvation environments.
References
1. Perticaroli, S.; Comez, L.; Paolantoni, M.; Sassi, P.; Lupi. L.; Fioretto, D.; Paciaroni, A.; Morresi, A. J. Phys. Chem. B,
24, 8262 (2010).
2. Perticaroli, S.; Comez, L.; Sassi, P.; Paolantoni, M.; Corezzi, S.; Caponi, S.; Morresi, A.; Fioretto, D. J. Non-Cryst.
Solids, 407, 472 (2015).
3. Perticaroli, S.; Comez, L.; Paolantoni, M.; Sassi, P.; Morresi, A.; Fioretto, D. J. Am. Chem. Soc., 133, 12063 (2011).
4. Comez, L.; Lupi, L.; Morresi, A.; Paolantoni, M.; Sassi, P.; Fioretto D. J. Phys. Chem. Lett., 4, 1188 (2013).
5. Comez, L.; Paolantoni, M.; Lupi, L.; Sassi, P.; Corezzi, S.; Morresi, A.; Fioretto D. J. Phys. Chem. B, 119, 9236 (2015).
6. Comez, L.; Paolantoni, M.; Corezzi, S.; Lupi, L.; Sassi, P.; Morresi, A.; Fioretto D. Phys. Chem. Chem Phys., 18, 8881
(2016).
7. Comez, L.; Paolantoni, M.; Sassi, P.; Corezzi, S.; Morresi, A.; Fioretto D. Soft Matter, 12, 5501 (2016).
Dyn-Biomol-6 ORAL CONTRIBUTIONS
Invited Talk
Coupling between protein and hydration water dynamics
Kevin Pounot1,2
, Yann Fichou3, Carlotta Marasini
4, Michaela Zamponi
5, Tilo
Seydel2, Bente Vestergaard
4, Giorgio Schiro
1, Martin Weik
1
1Institut de Biologie Structurale, Grenoble, France;
2Institut Laue Langevin, Grenoble, France;
3University of California Santa Barbara, USA;
4University of Copenhagen, Denmark;
5Heinz Maier-Leibnitz Zentrum, Garching, Germany
As molecular workhorses, proteins fulfill a multitude of tasks that keep the complex
machinery in biological cells alive. In order to be biologically active, most soluble proteins
require their surface to be covered with water. This so-called hydration water is generally
acknowledged to enable a protein to undergo the internal motions that are so fundamental for
its capacity to fulfill a specific biological function. Incoherent neutron scattering (INS) in
combination with selective deuterium labelling is a powerful tool that puts the focus either on
protein or on water motions on the ns-ps time scale and allows their dynamic coupling to be
studied. This coupling proves to decrease in tightness from intrinsically disordered, via
globular-folded to membrane proteins [1]. In particular, it is the translational diffusion of
hydration-water molecules on the protein surface that enables functionally-relevant motions
[2].
We have recently started focusing on the hydration-water dynamics of those proteins that can
form the pathological fibers involved in so-called protein aggregation diseases, such as tau
(Alzheimer’s) and -synuclein (Parkinson’s). So far, evidence has been found that hydration
water mobility is enhanced around tau amyloid fibers, a finding that identifies hydration water
entropy as a potentially universal driving force behind fiber formation [3].
REFERENCES
1. Gallat, F.X., Laganowsky, A., Wood, K., Gabel, F., van Eijck, L., Wuttke, J., Moulin, M., Hartlein, M.,
Eisenberg, D., Colletier, J.P., Zaccai, G., Weik, M., Dynamical coupling of intrinsically disordered proteins
and their hydration water: comparison with folded soluble and membrane proteins. Biophys J 103, 129
(2012)
2. Schiro, G., Fichou, Y., Gallat, F.X., Wood, K., Gabel, F., Moulin, M., Hartlein, M., Heyden, M., Colletier,
J.P., Orecchini, A., Paciaroni, A., Wuttke, J., Tobias, D.J., Weik, M., Translational diffusion of hydration
water correlates with functional motions in folded and intrinsically disordered proteins. Nature
communications 6, 6490 (2015)
3. Fichou, Y., Schiro, G., Gallat, F.X., Laguri, C., Moulin, M., Combet, J., Zamponi, M., Hartlein, M., Picart,
C., Mossou, E., Lortat-Jacob, H., Colletier, J.P., Tobias, D.J., Weik, M., Hydration water mobility is
enhanced around tau amyloid fibers. Proc Natl Acad Sci 112, 6365 (2015)
ORAL CONTRIBUTIONS Dyn-Biomol-7
Invited Talk
Dynamical Transition in Dry Proteins
Zhuo Liu, Juan Huang and Liang Hong
Department of Physics and Astronomy & Institute of Natural Sciences, Shanghai Jiao Tong
University, Shanghai, China 200240.
Water is widely assumed to be essential for life and protein function. Numerous
experiments have suggested that a minimum hydration level of h~0.2 (g water/g protein) is
required for enzymes to function. Correspondingly, h~0.2 has also been reported to be the
minimum hydration level required for the widely-studied protein “dynamical/glass transition”
at ~200 K, at which internal protein motions change from non-functional, glass-like, rigid,
harmonic vibrations to incorporating liquid-like, flexible, anharmonic dynamics required for
function. Here, we report on dynamic neutron scattering experiments on dry, perdeuterated
cytochrome P450 and green fluorescent protein complemented by molecular dynamics
simulation. The perdeuteration highlights collective motions of heavy atoms, which were
masked in the previous experiments on hydrogenated protein counterparts. The results show
that a ~200 K glass transition is present in dry proteins arising primarily from collective
heavy-atom motion. The glass transition is thus an intrinsic property of the energy landscape
of the proteins. These findings call for a reappraisal of the effects of water on protein
dynamics and function, and suggest that water may only amplify functional protein motions
that were intrinsically already present.
Dyn-Biomol-8 ORAL CONTRIBUTIONS
Invited Talk
Biophysics of Waters at Protein Surfaces and Proteins at
Water Interfaces
Alfonso De Simone
Department of Life Sciences, Imperial College London
Understanding the many roles of waters in biology is a top scientific challenge that requires
crossing the disciplinary boundaries between structural biology and statistical mechanics.
Water is not only the solvent of life, but indeed has specific roles in relevant biomolecular
mechanisms in the cell, including protein-protein interactions, protein folding and
macromolecular assembly. The physical properties of the active waters in these processes can
be extremely different from those of the bulk solvent. In this context, we employ molecular
dynamics simulations intertwined with experiments of biomolecular NMR [1] to dissect the
balance between entropic and enthalpic terms in the hydration of macromolecules [2] and to
ultimately address the dynamical and structural properties of waters at the protein surfaces [3-
6] and of proteins at water interfaces [7-8].
REFERENCES
1. De Simone, A., Dhulesia, A., Soldi, G., Vendruscolo, M., Hsu, ST, Chiti F, Dobson CM. PNAS 108,
21057-62 (2012)
2. Biedermann, F., Uzunova, V., Scherman, O.A., Nau, W., De Simone, A., JACS 34, 15318-23 (2012).
3. De Simone A, Dodson G, Verma CS, Zagari A, Fraternali F, PNAS 102, 7535-7540 (2005).
4. Vitagliano L, Berisio R, De Simone A, Biophys. J. 100, 2253-61 (2011).
5. Colombo G, Meli M, De Simone A, Proteins 70, 863-72 (2008).
6. Sanz-Hernandez M, De Simone A (2017) in press
7. De Simone A, Kitchen C, Kwan AH, Sunde M, Dobson CM, Frenkel D. PNAS 109 6951-6 (2012).
8. Sanz-Hernandez M, Kwan AH, Sunde, M, De Simone A (2017) in press
ORAL CONTRIBUTIONS Dyn-Biomol-9
Invited Talk
Protein internal dynamics in solution
Ralf Biehl
Jülich Centre for Neutron Science JCNS (JCNS-1) & Institute of Complex Systems (ICS-1),
Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
The biological function of proteins is often related to large-scale domain motions, which are
sometimes induced or suppressed by the binding of a substrate or due to cosolvents.
Configurational changes are often observed by methods like x-ray crystallography giving a
static image of the protein structure and suppressing large-scale domain motions, which occur
in solution. Observed configurational changes can be related to the substrate binding or the
crystal packing, which favors specific configurations. On the other side domain motions can
be related to soft hinges, flexible linker regions or -as in the case of natively unfolded
proteins- be intrinsic to the unfolded structure if the protein is unrestricted in solution. These
large-scale domain motions in solution cannot be observed by X-ray crystallography or NMR
spectroscopy. Small angle scattering by X-rays or neutrons in combination with neutron spin
echo spectroscopy (NSE) can be used to observe configurational changes and equilibrium
dynamics between functional domains on several nanoseconds.
I present here examples of large-scale structure determination by SANS and SAX combined
with NSE to determine the dynamics of the proteins on nanometer length scale and a
timescale up to hundred nanoseconds. Different types of motions related to the structure can
be observed. Phosphoglycerate kinase shows a clear hinge motion. Lactoferrin shows a
dumbbell structure with
transition of a rigid protein to an unfolded chain with 4 disulfide bonds can be observed
showing the restriction of the disulfide bonds. Immunoglobulin 1 (IGG1) presents a strong
dynamics due to the short linkers connecting the Fc with the Fab fragment. Analysis by a
Ornstein-Uhlenbeck process result in the determination of friction and spring constants.
Overall neutron scattering is shown to be a unique tool to examine the micromechanics of
proteins on the length scale of domains with the ability to examine forces and friction.
REFERENCES
1. Inoue, R.; Biehl, R.; Rosenkranz, T.; Fitter, J.; Monkenbusch, M.; Radulescu, A.; Farago, B.; Richter, D.
Biophys J, 99 (7), 2309 (2010).
2. Sill, C.; Biehl, R.; Hoffmann, B.; Radulescu, A.; Appavou, M.-S.; Farago, B.; Merkel, R.; Richter, D. BMC
Biophys., 9 (1), 7 (2016).
3. Stingaciu, L. R.; Ivanova, O.; Ohl, M.; Biehl, R.; Richter, D. Sci. Rep., 6, 22148 (2016).
Dyn-Biomol-10 ORAL CONTRIBUTIONS
Invited Talk
Dynamics of macromolecular systems by means of Nuclear
Magnetic Resonance Relaxometry
Danuta Kruk
Faculty of Mathematics and Computer Science, University of Warmia and Mazury in Olsztyn,
Słoneczna 54, 10-710 Olsztyn, Poland
Nuclear Magnetic Resonance (NMR) relaxometry is a unique tool to study molecular
dynamics [1,2]. In contrary to “standard” NMR experiments which are performed at a single
magnetic field (resonance frequency), by applying so called Fast Field Cycling (FFC)
technology one can the magnetic field covering five orders of magnitude in the resonance
frequency. In consequence, by FFC NMR relaxometry one can detect motional processes
across a huge range of time scales (from ms to ps) by single experiment. Most importantly,
frequency dependent NMR relaxation studies have the exceptional potential to reveal the
underlying mechanisms of molecular motion (not only its time scale). Thus, one can link
macroscopic quantities describing properties of complex molecular systems (like food
products) with the dynamics of their components, probed on the molecular level.
The potential of NMR relaxometry will be demonstrated by showing numerous examples of
studies performed for macromolecular systems including, among others, hydrogels,
dendrimers and food products. These systems are highly structured and heterogeneous. They
are complex mixtures of water, biopolymers (proteins and polysaccharides), sugars and
colloid particles. NMR relaxometry gives insight into dynamical properties of these
components and their mutual interactions and allows to access different phases (solid/liquid,
water/protein, etc.). Especially one can track water migration in the complex organic matrix.
The studies of the molecular dynamics involve displacements (translational diffusion) which
influences the contact of water with other components of the systems, changes in the
molecular orientation (rotational dynamics) which leads to structure rearrangements and
internal dynamics of the macromolecular components.
REFERENCES
1. Kruk D., Herrmann A., Rossler EA., Field-cycling NMR relaxometry of viscous liquids and polymers,
Progress in Nuclear Magnetic Resonance Spectroscopy 63, 33-64 (2012).
2. Fujara F., Kruk D., Privalov A., Solid State Field-Cycling NMR Relaxometry: Instrumental Improvements
and New Applications, Progress in Nuclear Magnetic Resonance Spectroscopy 82, 39-69 (2014).
ORAL CONTRIBUTIONS Dyn-Biomol-11
Invited Talk
Using Multi-Order Time Correlation Functions (TCFs) to
Elucidate Biomolecular Reaction Pathways from
Microsecond Single-Molecule Fluorescence Experiments
Carey Phelps, Brett Israels, Morgan C. Marsh, Peter H. von Hippel, and
Andrew H. Marcus*
Oregon Center for Optical, Molecular and Quantum Science, Institute of Molecular Biology
and Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403,
United States
Recent advances in single-molecule fluorescence imaging have made it possible to perform
measurements on microsecond time scales. Such experiments have the potential to reveal detailed
information about conformational changes in biological macromolecules, including the reaction
pathways and rearrangements involved in sequence-specific DNA ‘breathing’ and the assembly of
protein-nucleic acid complexes. Because microsecond single-molecule trajectories often involve
‘sparse’ data – i.e., they contain relatively few data points per unit time – they cannot be easily
analyzed using the standard protocols that were developed for single-molecule experiments carried out
with tens-of-millisecond time resolution and high ‘data density.’ We here describe an approach based
on time correlation functions (TCFs) to analyze microsecond single-molecule fluorescence
measurements, and thereby identify short-lived intermediates that lie on the reaction pathways
connecting relatively long-lived reactant and product states. We study a specific biologically relevant
example of the assembly mechanism of the single-stranded (ss) DNA binding protein (gp32) of the T4
bacteriophage replication complex onto a model DNA replication fork. We performed microsecond
single-molecule Förster resonance energy transfer (smFRET) measurements of Cy3/Cy5 labeled
primer-template (p/t) DNA constructs in the presence of gp32. These experiments probe the distance
between Cy3/Cy5 chromophores, which label the ends of a short (15 nucleotide) segment of ssDNA,
and permit us to track the stochastic inter-conversions between various protein-bound and unbound
states of the ssDNA. Our results indicate the presence of short-lived intermediates critical to the
assembly of ssDNA binding proteins at replication forks.
REFERENCES
1. Phelps, C., B. Israels, D. Jose, M. C. Marsh, P. H. von Hippel, and A. H. Marcus. Using multi-order time
correlation functions (TCFs) to elucidate biomolecular reaction pathways from microsecond single-
molecule fluorescence experiments. J. Phys. Chem. B, 120, 13003-13016 (2016).
2. Phelps, C., B. Israels, D. Jose, M. C. Marsh, P. H. von Hippel, and A. H. Marcus, Using microsecond single-
molecule FRET to determine the assembly pathways of T4 ssDNA binding protein onto model DNA
replication forks. Proc. Nat. Acad. Sci. + Plus, 114 (2017).
Dyn-Biomol-12 ORAL CONTRIBUTIONS
Invited Talk
Water in Aqueous Solutions of Biomolecules
Ryusuke Nozaki
Department of Physics, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
Dielectric spectroscopy is one of the powerful tools used to investigate aqueous solutions of
biomolecules, especially from the viewpoint of molecular dynamics. Aqueous solutions of
globule proteins have been extensively studied by many researchers via dielectric
spectroscopy. Three relaxation processes are commonly observed in aqueous solutions of
globule proteins such as myoglobin in the frequency range from 1 MHz to 20 GHz [1]. It has
been suggested that these processes originate from solute biomolecules (~1-10MHz), water
molecules (~20GHz) and interacting water molecules (bound water, ~10-100MHz).
We have investigated dielectric properties of aqueous solutions of amino acids and collagens
[2]. Putting glycine into water does not increase the viscosity of the aqueous solution very
much. A new dielectric relaxation process appears around 2GHz and the dielectric relaxation
strength of water decreases as has been reported [3]. Relaxation frequency of the new process
can be attributed to the rotational diffusion of the glycine molecule governed by the Stokes-
Einstein-Debye law with viscosity of pure water. Since glycine molecule holds hydrated
waters, relaxation strength of water decreases. On the other hand, adding collagen
(atelocollagen from tilapia scale) into water drastically increases the viscosity of the aqueous
solution. However, there is essentially no difference between dielectric dispersions of pure
water and such aqueous solution of collagen. This experimental result indicates that
interaction between water and collagen molecules is not very strong and the most of water in
the solution is free water. The high viscosity of the solution is due to a kind of network
structure composed of collagen molecules and such network folds usual water. Behaviors of
water in aqueous solutions of biomolecules strongly depends on the kinds of biomolecule.
REFERENCES
1. Pethig, R., Protein-Water interactions determined by dielectric methods, Annu. Rev. Phys. Chem. 43, 177-
205 (1992).
2. Kawamata, H. et. al., Hierarchical viscosity of aqueous solution of tilapia scale collagen investigated via
dielectric spectroscopy between 500 MHz and 2.5 THz, Sci. Rep. 7, 45398 (2017).
3. Sato, T. et. al., Dielectric relaxation spectroscopy of aqueous amino acid solutions: dynamics and
interactions in aqueous glycine, J. Mol. Liq. 117, 93-98 (2005).
ORAL CONTRIBUTIONS Dyn-Biomol-13
Invited Talk
Dielectric Studies of Collagen Thin Films
Anna Panagopoulou, Simone Napolitano
1Laboratory of Polymer and Soft Matter Dynamics, Faculté des Sciences, Université Libre de
Bruxelles (ULB), Boulevard du Triomphe, Bruxelles 1050, Belgium
Collagen-based biomaterials gain significant technological interest due to their extraordinary
ferroelectric properties [1] and an excellent water binding ability, achieved via the presence of
triple helix in the tertiary structure of this protein present in a large number of biological
tissues. Dielectric measurements on the dynamics of hydration water in bulk collagen have
permitted to highlight the role of the motion of the protein surface in underhydrated
conditions[2].
In the form of thin films (thickness of 100 to 1200nm), these materials have already been
employed as biocompatible capacitive high accuracy humidity sensors [3]. However, no
information on the impact of nanoconfinement on the dynamics of this biomaterial is known.
Here we present the first dielectric measurements on collagen thin films prepared by spin
casting of solutions of Collagen I from bovine achilles tendon in acetic acid, over broad
frequency and temperature ranges. Separation of the electrodes at the nanoscale level,
nanocapacitor geometry, facilitated the detection of a weak dipolar dielectric relaxation,
otherwise hardly visible in analogous measurements on bulk underhydrated samples. The
temperature dependence of the relaxation time of the above mentioned process shows a clear
crossover at Tc = 210 K from an Arrhenius behavior at low T to a superArrhenius trend at
high T. Reducing the film thickness below about 10nm alters the T dependence and
dynamical behavior observed. The molecular origin of the dielectric relaxations, is discussed
in terms of the observed T dependence and of the effect of the amplitude of the E-field on the
dynamics.
REFERENCES
1. Fukada, E., Recent Developments of Polar Piezoelectric Polymers, IEEE 13,5 (2006).
2. Gainaru, C., Fillmer, A., Böhmer, R., Dielectric Response of Deeply Supercooled Hydration Water in the
Connective Tissue Proteins Collagen and Elastin, J. Phys.Chem. B 113, 12628 (2009).
3. Shapardanis, S., Hudpeth, M., Kaya, T., Gelatin as a new humidity sensing material:Characterization and
limitations, AIP Advances 4,127132 (2014).
Dyn-Biomol-14 ORAL CONTRIBUTIONS
Invited Talk
Glass Transition and Dynamics of Uncrystallized Water,
Ice and Hydrated Gelatin Studied by
Broadband Dielectric Spectroscopy
Kaito Sasaki+, Takahito Yasuda
*,
Rio Kita*+
, Naoki Shinyashiki*, Shin Yagihara
*
Micro/Nano Technology Center+ and Department of Physics, School of Science*
Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan
The glass transition and the dynamics of partially crystallized gelatin–water mixtures were
investigated using broadband dielectric spectroscopy over a wide range of frequencies (10
mHz to 50 GHz), temperatures (113–298 K), and concentrations (1–45 wt.%).[1-3] Three
dielectric relaxation processes (processes I, II, and III) were clearly observed. Processes I, II,
and III originate from uncrystallized water (UCW) in the hydration shells of gelatin, ice, and
hydrated gelatin, respectively. According to the results, a dynamic crossover of UCW, called
the Arrhenius to non-Arrhenius transition, occurs at the glass transition temperature of the
relaxation process of hydrated gelatin. The amount of UCW increases with increasing gelatin
content. However, above 35 wt.% gelatin, the amount of UCW becomes more dependent on
the gelatin concentration. This increase in UCW causes a decrease in the glass transition
temperature of the relaxation process of hydrated gelatin. The temperature dependence of the
relaxation time of ice in the partially crystallized mixtures with the gelatin concentrations
above 5 wt.% has nearly the same activation energy as pure ice made by slow
crystallization.[1,4] On the other hand, ice in the mixtures with the gelatin concentrations
below 4 wt.% shows change in the activation energy which is the same behavior as pure ice
made by rapid crystallization. [1,4]
REFERENCES
1. Yasuda, T., Sasaki, K., Kita, R., Shinyashiki, N., Yagihara, S., Dielectric Relaxation of Ice in Gelatin–
Water Mixtures, J. Phys. Chem. B. 121, 2896-2901 (2017).
2. Sasaki, K.,. Panagopoulou, A, Kita, R., Shinyashiki, N., Yagihara, S., Kyritsis, A., Pissis, P., Dynamics of
Uncrystallized Water, Ice, and Hydrated Protein in Partially Crystallized Gelatin-Water Mixtures Studied by
Broadband Dielectric Spectroscopy, J. Phys. Chem. B, 121, 265-272 (2017).
3. Sasaki, K., Kita, R., Shinyashiki, N., Yagihara, S., Glass Transition of Partially Crystallized Gelatin-Water
Mixtures Studied by Broadband Dielectric Spectroscopy, J. Chem. Phys., 140, pp 124506 (2014).
4. Sasaki, K., Kita, R., Shinyashiki, N., Yagihara, S., Dielectric Relaxation Time of Ice Ih with Different
Preparation, J. Phys. Chem. B, 120, 3950-3953 (2016).
ORAL CONTRIBUTIONS Dyn-Biomol-15
Invited Talk
Structural fluctuation and dynamics of protein in water: a
statistical mechanics theory
Fumio Hirata
Toyota Physical Chemical and Research Institute
In the present paper, we present a new concept and a theory of protein folding based on the
generalized Langevin equation, that describes the thermodynamic hypothesis by Anfinsen, or
“Anfinsen’s dogma.” [1-3] The concept sees the protein folding (or unfolding) process as a
shift of the Gaussian distribution of fluctuated structures, the first moment (average structure)
and the second moment (variance-covariance matrix) of which vary depending on changes of
thermodynamic conditions. The idea is not just “a pie in the sky.” Realization of the concept
requires the free energy surface of the protein in aqueous solution, as well as its first and
second derivatives with respect to atomic coordinates. Methods to calculate the free energy
surface of protein and its first derivative have been already established based on the 3D-
RISM/KH theory developed by Hirata and his coworkers. [4] On the other hand, a work to
calculate the second derivative is currently in progress in our group.
In the paper, we also present a theory to describe the kinetics of protein folding. [5]
Combining the time-dependent linear response theory with the generalized Langevin
equation, we can get an equation that describes the time evolution of protein structure induced
by changes in thermodynamic conditions: temperature, pressure, concentration of denaturant,
etc. Such an equation was derived recently by Hirata based on the linear response theory.
Provided that the variance-covariance matrix is given, the equation produces relaxation curves
from one state to another state, plotted against time, from which one may get a rate constant
for protein folding.
References
1. Kim, B., and Hirata, F., J. Chem. Phys., 138, 054108 (2012)
2. Hirata, F. and Akasaka, K., J. Chem. Phys., 142, 044110 (2015)
3. Anfinsen, C. B., Science, 181, No. 4096, 223 (1973)
4. Yoshida, N., Imai, T., Phongphanphanee, S., Kovalenko, A., and Hirata, F., J. Phys. Chem.B, 113, 873
(2009).
5. Hirata, F., J. Chem. Phys., 145, 234106 (2016)
Dyn-Biomol-16 ORAL CONTRIBUTIONS
Invited Talk
Protein Dynamic in Aqueous Solutions with Trehalose
Christoffer Olsson, Jan Swenson
Department of Physics, Chalmers University of Technology, SE-412 96 Göteborg Sweden
The disaccharide trehalose has often been shown to be an excellent stabilizing additive to
biological systems. It can protect biomolecules against various types of environmental
stresses, like cold or desiccation.1 Interestingly, it has also been shown that trehalose has
applications in the prevention of neurodegenerative diseases, such as Alzheimer’s disease,
due to its propensity for preventing protein aggregation.2 This anti-aggregation property and
its stabilizing properties open intriguing questions about the dynamics and structure of e.g.
proteins in solutions, which contains stabilizing co-solutes.
In this work, we present a dynamical and structural study of an aqueous solution of
myoglobin with trehalose, as studied by a combination of quasi-elastic neutron scattering and
neutron diffraction. In a good agreement with the water entrapment model,3 we show that the
protein is preferentially hydrated by a layer of water, and that trehalose forms relatively few
bonds directly to the protein surface. We also observe a substantial ordering of the protein
molecules with a well-defined inter-protein distance. This finding is in contrast to what is
observed for aqueous protein solutions without trehalose, where substantial protein clustering
occurs. Hence, the separation of the protein molecules in the presence of trehalose explains
why it can function as an anti-aggregation additive. Trehalose is also causing a slowing down
of the protein dynamics, which partly can explain why trehalose protects myoglobin against
heat induced denaturation.4 By combining the quasi-elastic neutron scattering data with
molecular dynamics simulations we are able to show some of the characteristic motions of the
different components in the studied three-component system. We discuss both the motions of
trehalose and how trehalose affects the motions of water and myoglobin.
REFERENCES
1. Cordone, L. et al. Proteins in Saccharides Matrices and the Trehalose Peculiarity: Biochemical and
Biophysical Properties. Curr. Org. Chem. 19, 1684-1706 (2015).
2. Liu, R., Barkhordarian, H., Emadi, S., Park, C. B. & Sierks, M. R. Trehalose differentially inhibits
aggregation and neurotoxicity of beta-amyloid 40 and 42. Neurobiology of disease 20, 74-81 (2005).
3. Belton, P. S. & Gil, A. M. IR and Raman spectroscopic studies of the interaction of trehalose with hen egg
white lysozyme. Biopolymers 34, 957-961 (1994).
4. Olsson, C., Jansson, H. & Swenson, J. The Role of Trehalose for the Stabilization of Proteins. The Journal
of Physical Chemistry B 120, 4723-4731 (2016).
ORAL CONTRIBUTIONS Dyn-Biomol-17
Invited Talk
Dynamics of biomolecules in non-aqueous glassy matrices
Maria Pachettia, Alessandro Paciaroni
b, Elpidio Tombari
c,
Simone Capacciolia,c
aDipartimento di Fisica, Università di Pisa, Largo Bruno Pontecorvo 3, I-56127, Pisa, Italy
bDipartimento di Fisica, Università di Perugia, Via A. Pascoli 1, 06123 Perugia, Italy
cIstituto per i Processi Chimico-Fisici-CNR, via G. Moruzzi 1, 56124 Pisa, Italy
Saccharides and polyols compose a well-known class of glass-formers, widely studied as bioprotectors. In fact,
glassy sugar matrices are mandatory for improving the long-term storage of lyophilized mixtures of
biomolecules (such as proteins, nucleic acids and hormones), partially arresting their dynamics at storage
temperature and protecting their native structure by the stresses produced during the lyophilization process [1, 2].
The mechanism of stabilization, of interaction between protein groups and sugar and the resulting coupled
dynamics are still not fully understood [1]. The present study deals with dynamics of mixtures composed by
lysozyme embedded in different bioprotectant matrices, such as sugars and polyols, obtained from freeze-drying
aqueous solutions of protein and excipient. Orientational dynamics has been studied by means of broadband
dielectric spectroscopy in a wide temperature range, spanning from the deep glassy state up to the denaturation
temperature. Some relaxation processes observed are strongly affected by the sample preparation and by the
thermal history while others have a more stable behavior, being mainly affected by temperature and by the
excipient viscosity. In particular, among them it is noteworthy the presence of a prominent and broad loss peak,
whose characteristic relaxation time exhibits a Vogel-Fulcher-Tammann temperature dependence and diverges
apparently in a temperature region where calorimetry shows the glass transition phenomenon [3]. As reported in
previous studies [4], the viscosity of solvent controls protein motions and functions. Such evidence was recently
confirmed by elastic neutron scattering for fast dynamics of lysozyme solvated in glassy non-aqueous matrices
[5]. The main result of our study confirms this tendency, namely that the viscosity of excipient matrix is a key
parameter, able to induce a marked change in protein slow dynamics.
REFERENCES
1. Mensink M. A., Frijlink H.W., van der Voort Maarschalk K., Hinrichs W. L.J., “How sugars protect
proteins in the solid state and during drying (review): mechanisms of stabilization in relation to stress
conditions”, Eur. J. Pharm. Biopharm. 114, 288–295 (2017).
2. Allison S.D., Chang B., Randolph T.W., Carpenter J.F., “Hydrogen bonding between sugar and protein is
responsible for inhibition of dehydration-induced protein unfolding”, Arch. Biochem. Biophys. 365, 289-
298 (1999).
3. Bellavia G., Giuffrida S., Cottone G., Cupane A., Cordone L., “Protein thermal denaturation and matrix
glass transition in different protein trehalose water systems”, J. Phys. Chem. B 115, 6340-6346 (2011).
4. Fenimore P.W., Frauenfelder H., McMahon B.H., Young R. D.,“Bulk-solvent and hydration-shell
fluctuations, similar to - and -fluctuations in glasses, control protein motions and functions”, Proc. Natl.
Acad. Sci. USA 101, 14408-14413 (2004).
5. Capaccioli S., Ngai K. L., Ancherbak S., Paciaroni A., “Evidence of coexistence of change of caged
dynamics at Tg and the dynamic transition at Td in solvated proteins”, J. Phys. Chem. B. 116, 1745−1757,
(2012).
Dyn-Biomol-18 ORAL CONTRIBUTIONS
Invited Talk
Role of water in hydrated protein structure. From solution
to the powders
Yuri Feldman
The Hebrew University of Jerusalem, Department of Applied Physics,
Edmond J. Safra Campus, Jerusalem 91904, Israel
Water is the universal solvent in nature. Does this imply, however, that its interaction with its environment is also a
universal feature? While this question maybe too fundamental to be answered by one method only, we present
evidence that the broadening of the dielectric spectra of water presents universal features of dipolar interactions with
different types of matrixes. If in aqueous solutions the starting point of water’s state can be considered as bulk, with
only partial interactions with the solute, then the state of water adsorbed in heterogeneous materials is determined by
various hydration centers of the inhomogeneous material (the matrix) and it is significantly different from the bulk. In
both cases, the dielectric spectrum of water is symmetrical and can be described by the Cole–Cole (CC) function.
The phenomenological model that describes a physical mechanism of the dipole–matrix interaction in complex
systems underlying the CC behavior has been applied to water adsorbed in porous glasses [1], clays [2] and hydrated
proteins [3,4]. It was then extended to analyses of the dynamic and structural behavior of water in nonionic and ionic
aqueous solutions [5-8]. The same model is used to analyze the CC relaxation processes in the Red Blood Cells (RBC)
suspensions by monitoring the RBC cytoplasm under different external conditions [9]. Dielectric measurements of
RBC suspensions in the frequency region of 100 MHz to 50 GHz as a function of aging or external glucose contartion
also reveal a distinct time point or glucose concentration after which the spectra are radically changed. This opens a
window of opportunity to exploit this for the non-invasive monitoring of diabetes or to non-invasive control of the
quality of Stored RBC in a Blood bank in order to manage the inventory.
REFERENCES
1. Puzenko, A., Ben Ishai, P., Feldman, Y., Cole-Cole Broadening in Dielectric Relaxation and Strange
Kinetics, Phys. Rev. Lett. , 105 037601-037604 (2010).
2. Vasilyeva, M.A., Gusev, Yu. A., Shtyrlin, V.G., Greenbaum (Gutina), A., Puzenko, A., Ben Ishai, P. and
Feldman, Yu., “Dielectric Relaxation of Water in Natural Layer Aluminosilicates”, Clays and Clay
Minerals, Vol. 62, pp. 62–73, (2014).
3. Kurzweil-Segev, Y., Greenbaum, A., Popov, I., Golodnitsky, D. and Feldman, Yu. “The role of the confined
water in the dynamic crossover of a hydrated Lysozyme powders”, PCCP, V.18, pp. 10992-10999, (2016)
4. Kurzweil-Segev, Y., Popov, I., Sagit, I., Solomonov, I., Feldman, Yu. “The mechanism of the dielectric
relaxation of the hydration water in native collagen fibrils”, PCCP (2017, submitted).
5. Levy, E., Puzenko, A., Kaatze, U., Ben Ishai, P., Feldman, Y., Dielectric spectra broadening as the signature
of dipole-matrix interaction. I. Water in nonionic solutions, J. Chem. Phys., 136 114502-114505 (2012).
6. Levy, E., Puzenko, A., Kaatze, U., Ben Ishai, P., Feldman, Y., Dielectric spectra broadening as the signature
of dipole-matrix interaction. II. Water in ionic solutions J. Chem. Phys., 136 114503-114506 (2012).
7. Puzenko, A., Levy, E., Shendrik, A., Talary, M.S., Caduff, A., Feldman, Y., Dielectric spectra broadening as
a signature for dipole-matrix interaction. III. Water in adenosine monophosphate/adenosine-5′-triphosphate
solutions, The Journal of chemical physics, 137 194502-194508 (2012).
8. Levy, E., Cerveny, S., Ermolina, I., Puzenko, A., Feldman, Y., Dielectric spectra broadening as a signature
for dipole-matrix interaction. IV. Water in amino acids solutions, J. Chem. Phys., 140 135104-135101-
135106 (2014).
9. Levy, E., Barshtein, G., Livshitz, L., Ben Ishai1, P. and Feldman, Yu., “The Vitality of Human RBC and its
connection to cytoplasmic water: I. The glucose concentration influence” Journal Physical Chemistry B, V.
120, pp. 10214−10220 (2016).
ORAL CONTRIBUTIONS Dyn-Biomol-19
Invited Talk
Dynamics Of Protein Hydration Shells, Dynamical
Transition, And Enzyme’s Function
Dmitry V. Matyushova
aDepartment of Physics and School of Molecular Sciences, Arizona State University, Tempe,
85287, Arizona, U.S.A.
Dynamics of water and protein are strongly coupled. Experiments probing the protein-water
interface are: absorption of radiation by protein solutions [1], dynamical transition in proteins
[2,3], and function of energy chains of biology [4]. The absorption of radiation in the THz
domain is strongly affected by protein-water dipolar cross correlations, which propagate long
distances (20-40 A) into the bulk. The high-frequency dielectric response of the interface does
not follow the predictions of the dielectric models as a result of a significant alteration of the
orientational structure of the interface introduced by the hydrated protein. The dynamical
transition is observed by neutron scattering and Moessbauer spectroscopy of hydrated
proteins. It amounts to a sharp increase of the atomic displacements at the temperatures above
the temperature of the dynamical transition. A course-grained model is proposed that assigns
this effect to softening of the protein vibrations caused by long-ranged forces produced by the
protein-water interface [2-3]. The dynamical transition occurs when the force-force relaxation
time enters the observation window of the spectrometer. The temperature of the dynamical
transition is reached at the point of equality between the relaxation and resolution times.
Ergodicity breaking occurring at the dynamical transition is shared by many protein enzymes
responsible for energy production in biology’s energy chains. These large protein complexes,
located in membranes of mitochondria, deliver cross-membrane electron flow. A general
design principle involves nonergodic sampling of the enzyme’s phase space. The inability to
sample the entire configuration space leads to the breakdown of the fluctuation-dissipation
relation. The result is a significant lowering of the activation barrier in redox enzymes [4] due
to an effectively higher temperature of enzyme’s operation. Chemical reactivity is accelerated
by natural enzymes by taking advantage of large-amplitude electro-elastic fluctuations of the
protein-water interface [4].
REFERENCES
[1] D. V. Matyushov, “Dipolar response of hydrated proteins”, J. Chem. Phys. 2012, 136, 085102.
[2] D. V. Matyushov and A. Y. Morozov, “Electrostatics of the protein-water interface and the dynamical transition in
proteins”, Phys. Rev. E 2011, 84, 011908.
[3] S. S. Seyedi and D. V. Matyushov, “Ergodicity breaking of iron displacement in heme proteins”, in preparation.
[4] D. V. Matyushov, “Protein electron transfer: is biology (thermo)dynamic?” J. Phys. Cond. Matter 2015, 27,
473001.
Dyn-Biomol-20 ORAL CONTRIBUTIONS
Invited Talk
Generalization of the slaving phenomenon to non-biological
aqueous solutions
Silvina Cerveny1,2
1 Centro de Física de Materiales (CSIC-UPV/EHU)-Material Physics Center (MPC), Paseo
Manuel de Lardizabal 5 (20018), San Sebastián, Spain.
2 Donostia International Physics Center (DIPC), San Sebastián, Spain.
Protein dynamics spans a large hierarchy of timescales, from picoseconds to milliseconds or even
longer times. These dynamics include motions of the protein itself (vibrations, rotations, and
transitions among different sub-states) as well as motions in the hydration shell and the bulk solvent
and all these motions are necessary for the functionality of the proteins. However, in the absence of
the solvent (dehydrated state), these motions are not produced. Therefore, water is seen as the ‘matrix
of life’ because its presence is essential for every bio-molecular process. Furthermore, it is also
accepted that the most important protein motions follow temperature dependences similar to the water
motions [1-2]. In the current literature this is called “slaving behavior” in the sense that the protein
motions are couple to motions in the surrounding solvent. However, this “slaving behavior” was
exclusively observed for protein solutions and not in other non-biological systems.
Recently [3], we showed that the slaving behavior is not only observed in protein solutions. Instead,
this behavior can be also observed in non-biological solutions of small peptides (-poly(lysine)). This
small molecule has no biological function although it has three-dimensional structure as that observed
in folded proteins. Moreover, by analyzing the dynamics of other materials with a much higher glass
transition temperature, we find that the slaving behavior is more common than was previously thought.
Here, we will show that aqueous solutions of poly(vinyl pyrrolidone), some polysaccharides and also
oligomers of n-lysine also show this particular behavior. Therefore, the crucial role of water for
protein dynamics can be extended to other types of macromolecular systems, where water is also able
to determine their conformational fluctuations. This investigation also opens a new route to understand
the slaving behavior observed for proteins.
REFERENCES
1. Fenimore, P. W.; Frauenfelder, H.; McMahon, B. H.; Young, R. D.,. PNAS, 101, 14408-14413 (2004).
2. Frauenfelder, H.; Chen, G.; Berendzen, J.; Fenimore, P. W.; Jansson, H.; McMahon, B. H.; Stroe, I. R.;
Swenson, J.; Young, R. D., PNAS, 106, 5129-5134 (2009).
3. Cerveny, S.; Combarro-Palacios, I.; Swenson, J., Evidence of Coupling between the Motions of Water
and Peptides. The Journal of Physical Chemistry Letters 7, 4093-4098 (2016)
ORAL CONTRIBUTIONS Dyn-Biomol-21
Invited Talk
Multiscale Approach for Water at Bio-Nano Interfaces.
Giancarlo Franzese
Secció de Física Estadística i Interdisciplinària–Departament de Física de la Matèria
Condensada, & Institute of Nanoscience and Nanotechnology (IN2UB), Universitat de
Barcelona, Marti i Franques 1, 08028 Barcelona, Spain.
I will present recent simulations and theoretical results about the dynamics and structure of
water at bio-interfaces (proteins and bio-membranes) and nano-interfaces (nanoparticles and
graphene sheets). By all-atoms simulations I will analyze how hydrophobic and hydrophilic
interfaces affect the properties of the vicinal water [1,2] and we will use the results in a multi
scale approach to develop the Many-Body Model (MBM) for water [3,4] that allow us to
extend our investigations to timescales and length-scales that would be unreachable in
atomistic simulations [5,6]. We will consider applications to protein folding [7] and design
[8], and self-assembly of nanoparticles-protein-corona [9].
REFERENCES
1. J. Martí, C. Calero, and G. Franzese, Structure and dynamics of water at carbon-based interfaces, Entropy
19, 135 (2017).
2. C. Calero, H. E. Stanley and G. Franzese. Structural Interpretation of the Large Slowdown of Water
Dynamics at Stacked Phospholipid Membranes for Decreasing Hydration Level: All-Atom Molecular
Dynamics. Materials, 9, 319 (2016).
3. V. Bianco, and G. Franzese, Critical behavior of a water monolayer under hydrophobic confinement,
Scientific Reports 4, 4440 (2014).
4. L. E. Coronas, V. Bianco, A. Zantop, and G. Franzese, Liquid-Liquid Critical Point in 3D Many-Body
Water Model, arXiv:1610.00419 (2016).
5. F. de los Santos, and G. Franzese, Relations between the diffusion anomaly and cooperative rearranging
regions in a hydrophobically nanoconfined water monolayer, Physical Review E, 85, 010602(R) (2012).
6. M. G. Mazza, K. Stokely, S. E. Pagnotta, F. Bruni, H. E. Stanley, and G. Franzese, More than one dynamic
crossover in protein hydration water, Proceedings of the National Academy of Sciences of the USA 108,
19873 (2011).
7. V. Bianco, and G. Franzese, Contribution of Water to Pressure and Cold Denaturation of Proteins, Physical
Review Letters 115, 108101 (2015).
8. V. Bianco, G. Franzese, C. Dellago, and I. Coluzza, Role of water in the selection of stable proteins at
ambient and extreme thermodynamic conditions, Physical Review X, accepted (2017).
9. O. Vilanova, J. J. Mittag, P. M. Kelly, S. Milani, K. A. Dawson, J. O. Rädler and G. Franzese,
Understanding the Kinetics of Protein − Nanoparticle Corona Formation, ACS Nano 10, 10842 (2016).
Dyn-Biomol-22 ORAL CONTRIBUTIONS
Invited Talk
Protein-solvent couplings, as obtained from NMR, QENS,
and MD simulations on elastin and elastin-like peptides in
aqueuos mixtures
Dominik Demuth, Michael Vogel
Technische Universität Darmstadt, Institut für Festkörperphysik, Hochschulstraße 6, 64289
Darmstadt, Germany
The biological function of proteins depends in many cases on the existence of a hydration
shell. It is proposed that the solvent “slaves” or “plasticizes” the protein dynamics[1,2]. While
there is consensus that the presence of a solvent is essential, the underlying interactions are
still a matter of debate.
Here, we combine NMR and QENS measurements with MD simulations to investigate elastin
in aqueuos mixtures. We exploit that all used methods enable selective studies of solvent and
protein dynamics. Temperature dependent QENS studies reveal a protein dynamical transition
at ~200K. 13C NMR allows us to determine the changes in elastin dynamics when
successively replacing water by glycerol or modulating the solvation levels[3], where 2H
NMR yields the resulting changes in the solvent viscosity[4,5]. MD simulations yield an even
more detailed picture about solvent- and temperature dependent structure and dynamics of the
hydrogen-bond network at the elastin-solvent interface.
We connect the activation of elastin fluctuations and glycerol solvation levels and how
protein mobility increases with solvent viscosity. We then show that in the presence of elastin
the distribution of correlation times of binary solvents is both slowed down and broadened
compared to bulk systems but is less sensitive to composition.
REFERENCES
1. Frauenfelder, H., Chen, G., Berendzen, J., Fenimore, P.W., Jansson, H., McMahon, B.H., Stroe, I.R.,
Swenson, J., Young, R.D., A unified model of protein dynamics, PNAS. 106, 5129–5134 (2002).
2. Doster, W., The dynamical transition of proteins, concepts and misconceptions. Eur. Phys. J. 37, 591–602
(2008)
3. Demuth D. et al., Effects of solvent concentration and composition on protein dynamics: 13C MAS NMR
studies of elastin in glycerol–water mixtures, BBA. 1854, 995–1000. (2015)
4. Lusceac, S.A. Rosenstihl, M., Vogel, M., Gainaru, C., Fillmer, A., Böhmer, R., NMR and dielectric studies
of hydrated collagen and elastin: evidence for a delocalized secondary relaxation, J.Non-Cryst.Solids. 357,
655–663 (2011)
5. Kämpf, K., Kremmling, B., Vogel, M., Vanishing amplitude of backbone dynamics causes a true protein
dynamical transition: 2H NMR studies on perdeuterated C-phycocyanin. Phys. Rev. E 89, 032710 (2014)
ORAL CONTRIBUTIONS Dyn-Hetero-1
Invited Talk
2D and 3D colloidal glass transitions: Does dimensionality
really matter?
Eric R. Weeks1, Skanda Vivek
1, Colm Kelleher
2, and Paul M. Chaikin
2
1 Emory University, Atlanta, GA 30322 USA
2 New York University, New York, NY 10003
We use microscopy to study both 3D and quasi-2D colloidal systems as they approach their
glass transitions as their concentrations are increased. We examine a 3D hard-sphere-like
system, a 2D hard-sphere-like system, and a 2D soft-sphere system. All samples are
bidisperse to frustrate crystallization. We measure the relaxation time scales for translational
motion and structural reorientation, both of which dramatically increase as the glass transition
is approached. A strong contrast is seen between the 2D and 3D data close to the glass
transition, in that structural reorientation is markedly slower in 2D than in 3D. This is due to
coordinated particle motion where particles move significant distances without changing their
positions relative to their neighbors. By considering only motion relative to one's neighbors,
the two relaxation time scales agree much better in both 2D and 3D. Overall, our results
agree with recent simulation results [1] in that 2D and 3D glass transitions appear
qualitatively different, but we extend their observations and suggest that the differences are
removed upon adjusting the measurement method [2]. Our conclusions are similar to recent
work by Shiba et al. [3] and Illing et al. [4].
REFERENCES
1. Flenner, E. Szamel, G., “Fundamental differences between glassy dynamics in two and three dimensions,”
Nat. Commun. 6, 7392 (2015).
2. Vivek, S., Kelleher, C.P., Chaikin, P.M., Weeks, E.R., “Long-wavelength fluctuations and the glass
transition in two dimensions and three dimensions,” Proc. Nat. Acad. Sci. 114, 1850-1855 (2017).
3. Shiba, H., Yamada, Y. Kawasaki, T., Kim, K., “Unveiling dimensionality dependence of glassy dynamics:
2D infinite fluctuation eclipses inherent structural relaxation,” Phys. Rev. Lett. 117, 245701 (2016).
4. Illing, B., Fritschi, S., Kaiser, H., Klix, C.L., Maret, G., Keim, P., “Mermin-Wagner fluctuations in 2D
amorphous solids,” Proc. Nat. Acad. Sci. 114, 1856-1861 (2017).
Dyn-Hetero-2 ORAL CONTRIBUTIONS
Invited Talk
Why are Dynamics Heterogeneous? Reversibility and the
Spatial Distribution of Constraint
Shibu Saw, Gang Sun and Peter Harrowell
School of Chemistry, University of Sydney, Sydney, Australia
Any disordered configuration can, in principle, be analysed in terms of the degree to which it
exerts constraint on the motion of the particles that make it up. In an amorphous
configuration, these constraints will be heterogeneously distributed and their definition
presents a challenge. At T = 0 they can be identified by Maxwell constraint counting, at least
when particle interactions do not extend far beyond the particle radius. It has been proposed
that the individual particle Debye-Waller factor provides a more general measure of
constraint. In this talk we examine the T dependence of the spatial distribution of the Debye-
Waller factors in glass forming liquids and the relationship between this distribution and that
of relaxation kinetics.
ORAL CONTRIBUTIONS Dyn-Hetero-3
Invited Talk
Dynamic heterogeneity and density scaling of ionic liquids
compared to van der Waals liquids near the glass transition
Andrzej Grzybowski , Katarzyna Grzybowska, Żaneta Wojnarowska, Marian
Paluch
Institute of Physics, University of Silesia, ul. Uniwersytecka 4, 40-007 Katowice, Poland
In the last decade, the formalism of the four-point time-dependent correlation function, usually
represented by the four-point dynamic susceptibility 4(t), has been successfully applied to study the
molecular dynamics, which is heterogeneous in space and time [1]. Studies conducted in the same
years have shown that the density scaling of different dynamic quantities as a function of /T (where
the scaling exponent is a material constant, and and T denote density and temperature) is very well
satisfied by many supercooled van der Waals liquids and polymer melts [2]. Although this scenario
had not been expected for ionic liquids due to some results of simulations in simple models, we
showed for the first time in 2010 that the ionic conductivity relaxation times of a supercooled aprotic
ionic liquid obey the power law density scaling [3]. Later, the density scaling validity has been
established in case of many other aprotic and protic ionic liquids [4]. However, the dynamic
heterogeneity of supercooled ionic liquids has until recently remained terra incognita. Our recent comparative
analysis of ionic liquids and their non-ionic bases has yielded a very interesting result that the degree of
dynamic heterogeneity significantly decreases if the intermolecular interactions are dominated by electrostatic
forces [5]. In this presentation, our latest results will be also discussed, which show how the density
scaling and the dynamic heterogeneity are manifested in ionic liquids compared to van der Waals
liquids and polymers near the glass transition in the wide temperature-pressure-density range.
Consequently, in case of ionic liquids, we verify an isochronal decoupling earlier established [6,7]
between the structural or segmental relaxation time and the dynamic heterogeneity measure,
4
max
=max(4(t)), which can be quantified by the density scaling laws obeyed by and
4
max
with
different values of the scaling exponents [8].
REFERENCES
1. Berthier, L., Biroli, G., Bouchaud, J.-P., Cipelletti, L., El Masri, D., L’Hôte, D.et al., Science 310, 1797 (2005).
2. Floudas, G., Paluch, M., Grzybowski, A., Ngai, K., Molecular Dynamics of Glass-Forming Systems: Effects of
Pressure (Springer-Verlag), chap. 2, 2011.
3. Paluch, M., Haracz, S., Grzybowski, A., Mierzwa, M., Pionteck, J. et al., J. Phys. Chem. Lett. 1, 987 (2010).
4. Wojnarowska, Z. and Paluch, M., chap. 4 in Dielectric Properties of Ionic Liquids (Springer-Verlag), 2016.
5. Grzybowska, K., Grzybowski, A., Wojnarowska, Z., Knapik, J., M. Paluch, Sci. Rep. 5, 16876 (2015).
6. Grzybowski, A., Kołodziejczyk, K., Koperwas, K., Grzybowska, K., M. Paluch, Phys. Rev. B 85, 220201(R)
(2012).
7. Koperwas, K., Grzybowski, A., Grzybowska, K., Wojnarowska, Z., Sokolov, A. P., Paluch, M., Phys. Rev. Lett.
111, 125701 (2013).
8. Grzybowski, A., Koperwas, K., Kolodziejczyk, K., Grzybowska, K., Paluch, M., J. Phys. Chem. Lett. 4, 4273
(2013).
Dyn-Hetero-4 ORAL CONTRIBUTIONS
Invited Talk
Defracturing the Glass Transition:
Can the Differing Interpretations be Unified?
C.Patrick Royall1,2,3,4
1 HH Wills Physics Laboratory, Tyndall Avenue, Bristol, BS8 1TL, UK
2 School of Chemistry, University of Bristol, Cantock Close, Bristol, BS8 1TS, UK
3 Centre for Nanoscience and Quantum Information, Tyndall Avenue, Bristol, BS8 1FD, UK
4 Department of Chemical Engineering, Kyoto University, Kyoto 615-8510, Japan
Our understanding of the mechanism by which the viscosity of supercooled liquids increase
by many decades is hampered by the difficulty in discriminating apparently incompatible
theoretical approaches. The challenge lies in equilibrating samples at sufficient supercooling
with experimental or numerical techniques. Recently, considerable progress has been made in
obtaining data which can help to discriminate such theories, in both molecular experiments
[1] and simulation [2]. Some of these new data tend to support theories which imagine a
thermodynamic origin of the glass transition - in contrast to a predominately dynamic one.
Nevertheless, plenty of compelling evidence in support of dynamic facilitation (which posits
that the glass transition is driven by a dynamical phase transition) exists [3,4]. Here we use
novel techniques to obtain very deeply supercooled configurations in an atomistic
glassformer. These enable an investigation of the dynamical transition of facilitation. We find
that the dynamical transition has a lower critical point. Our deeply supercooled configurations
also give access to the configurational entropy, from which we can locate the Kauzmann
temperature. Remarkably, within the accuracy of our approach, this point where the
thermodynamic theories suggest a phase transition lies at the same temperature as the lower
critical point of the dynamical transition. Our findings may lead to a path to reconcile the
competing thermodynamic and dynamic interpretations of the glass transition [5].
REFERENCES
1. Albert, S.; et al. Fifth-order susceptibility unveils growth of thermodynamic amorphous order in glass-formers
Science, 352, 1308—1311 (2016).
2. Berthier, L et al. Breaking the glass ceiling: Configurational entropy measurements in extremely supercooled
liquids ArXiV, 1704.08257 (2017).
3. Hedges, L. et al. Dynamic Order-Disorder in Atomistic Models of Structural Glass Formers Science 323, 1309-
1313 (2009).
4. Speck, T.; Malins, A. & Royall, C. P. First-Order Phase Transition in a Model Glass Former: Coupling of Local
Structure and Dynamics Phys. Rev. Lett., , 109, 195703 (2012).
5. Turci, F.; Royall, C. P. & Speck, T. Non-Equilibrium Phase Transition in an Atomistic Glassformer: the
Connection to Thermodynamics ArXiV, 1603.06892 (2016).
ORAL CONTRIBUTIONS Dyn-Hetero-5
Invited Talk
Determination of the cooperativity length in a
glass forming liquid
Reiner Zorn1, Yeong-Zen Chua
2, Christoph Schick
2, Jürn W. P. Schmelzer
2,
Olaf Holderer3, Ernst Donth
4
1Jülich Centre for Neutron Science, Forschungszentrum Jülich, 52425 Jülich, Germany
2Institute of Physics and Competence Centre CALOR, University of Rostock,
Albert-Einstein-Str. 23-24, 18051 Rostock, Germany 3Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum,
Forschungszentrum Jülich, Lichtenbergstr. 1, 85748 Garching, Germany 4Wachbergstr. 3, 01326 Dresden, Germany
Although the idea of a ‘characteristic’ or ‘cooperativity’ length scale ξ related to the glass
transition is now wide-spread, there is much less consensus on whether this length scale can
be related to thermodynamic fluctuations and, if yes, one has to consider temperature
fluctuations δT. The crucial experiment to this end has to compare values of ξ from
‘thermodynamic’ formulae to independent values from structural-dynamics experiments.
Proposals for the latter often involve more-than-two-point correlations which are difficult to
access in experiments.
Recent advances in quasielastic neutron scattering (QENS) by neutron spin echo (NSE) and
AC calorimetry enable an experiment with the aim of determining the cooperativity length in
glass forming materials proposed more than a decade ago by Donth [1]. The basic idea of this
experiment is to assign a length scale to the AC-calorimetric relaxation time using the spatial
resolution of QENS. The main problem is to find a range of relaxation times that is accessible
by both methods. The problem is aggravated by the fact that in the QENS part one needs to
observe the self-correlation which is usually the weaker side of NSE.
Although the dynamic gap could not be closed completely, we can present first results on
propylene glycol [2]. The results indicate a better agreement with a calculation involving
temperature fluctuations (δT≠0).
REFERENCES
1. Donth E., Can dynamic neutron scattering help to understand a thermodynamic variant of an internal
quantum-mechanical experiment in the angstrom range? Eur. Phys. J. E 12, 11–18 (2003).
2. Chua Y. Z., Zorn R., Holderer O., Schmelzer J. W. P., Schick C., Donth E., Temperature fluctuations and
the thermodynamic determination of the cooperativity length in glass forming liquids, J. Chem. Phys. 146,
104501 (2017).
Dyn-Hetero-6 ORAL CONTRIBUTIONS
Oral
Nano-particle resolved studies of deeply supercooled liquids
reveal growing dynamic and structural lengthscales
James E. Hallett1, Francesco Turci
1 and C. Patrick Royall
1,2
1University of Bristol, H.H. Wills Physics Laboratory, Tyndall Avenue, United Kingdom
2 Kyoto University, Department of Chemical Engineering, Kyoto 615-8510, Japan
The physics underlying the glass transition is a major outstanding problem in condensed
matter. Central to resolving this problem is whether there is some kind of thermodynamic
glass transition or whether the massive slowdown of 14 decades in relaxation time is a
dynamic phenomenon [1]. Among the key pieces of evidence in support of a thermodynamic
phase transition would be concurrent growing dynamic and structural lengthscales, but
measuring such quantities requires particle-resolved studies of colloids and simulations which
have hitherto been unable to access states more deeply supercooled than the mode-coupling
transition (4-5 decades of dynamic slowing). Crucially, at deeper supercoolings, theories such
as random first order transition theory predict a different mechanism of relaxation [1],
underlining the importance of studying deep supercooling.
Using super-resolution microscopy, we present results on 250 nm radius nanoparticles which
are much smaller than any previously studied, and access deeper supercoolings than ever
before for particle resolved studies. Unlike previous results at weaker supercooling [2,3], we
find that a significant number of particles persist in icosahedral locally favoured structures
(LFS), and that these structures display slow dynamics, exhibit a growing static lengthscale
with density and are present in regions of high static overlap [4]. These findings may help to
resolve the glass transition – in favour of an underlying thermodynamic transition [5].
REFERENCES
1. Berthier, L. and Biroli, G., Rev. Mod. Phys. 83, 587 (2011).
2. Royall, C.P. and Williams, S.R., Phys. Rep. 560 1 (2015).
3. Karmakar, S. et al., Annu. Rev. Cond. Matt. Phys. 5, 255 (2014).
4. Berthier, L., Phys. Rev. E 88, 022313 (2013).
5. Hallett, J.E., Turci, F. and Royall, C.P., Submitted (2017).
ORAL CONTRIBUTIONS Dyn-Hetero-7
Oral
Revealing the structural origin of dynamic heterogeneity in
glass-forming liquids
Hua Tong and Hajime Tanaka
Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-
8505, Japan
When a liquid is supercooled and approaches the glass transition, the dynamics drastically
slows down accompanied by the growth of its spatial heterogeneity. The origin of such slow
dynamics and heterogeneity has been a long standing unsolved problem in condensed matter
physics and material science. Here we address this problem by introducing a new approach to
reveal their structural origin, which may be valid for a wide class of glass-forming liquids.
We find that the development of dynamic heterogeneity can be well predicted in the way of
progressive spatial coarse-graining of the initial static structure: the mobility field gradually
spreads from most disordered regions towards more ordered regions systematically following
a relevant structural order parameter field, which captures many-body (orientational)
correlations with a close link to local free energy. This clearly indicates that it is the static
order that controls dynamic heterogeneity. Furthermore, we reveal that the correlation
between the static and dynamic fields maximizes at a specific spatial coarse-graining length
and time scale, which are respectively in accord with the dynamic correlation length and the
structural relaxation time independently determined by traditional methods. This implies that
the dynamical slowing down is a consequence of the growing static correlation. We also find
that the close correlation between the fast cage-rattling and slow glassy dynamics emerges as
a natural result of their connections to the common static structure. Our findings strongly
indicates a common static structural origin for the fast and slow dynamics of a supercooled
liquid.
REFERENCES
1. Tong, H. and Tanaka, H., Revealing the structural origin of dynamic heterogeneity in glass-forming
liquids, submitted (2017).
Dyn-Hetero-8 ORAL CONTRIBUTIONS
Invited Talk
Segmental relaxation and dynamic glass transition in
biopolyesters : relationship between cooperativity length,
activation energy and free volume.
S. Araujo1, 2
, N. Delpouve1, L. Delbreilh
1*, A. Saiter
1, E. Dargent
1
1.Normandie Univ, UNIROUEN, INSA Rouen, CNRS, GPM, 76000 Rouen, France
2. CEREMA, Direction Territoriale Normandie Centre, 76121 Le Grand Quevilly, France
Biopolyesters, like polylactides, are promising biobased polymers in order to replace petroleum-
based polymers mainly for packaging applications. Main issues with polylactides are their relative
mechanical stiffness and their weak barrier properties. In order to solve this weaknesses several
scenarios have been (and are) investigated: modifications of the macromolecular microstructures
by thermo-mechanical treatments1, modifications of intermolecular interactions by the use of
plasticizing molecules,… All these approaches tend to improve very different properties like
ductility and barrier properties of these biopolymers but very few studies deal with the physical
impact of these processes on the macromolecular dynamics.
With this study we propose to investigate the effect of these processes by studying the
modifications they produce on the segmental relaxation. The impact on the dynamic glass
transition is observed and analyzed regarding the modifications of the temperature dependence of
the segmental relaxation, of the cooperative length-scale variation with temperature. Different
approaches have been used to quantify dynamic heterogeneities in the liquid like state and a
discussion is proposed for the application of these models on several polymers2.
In these structured polymeric systems, the modifications of the microstructure add a major
complexity in the estimation of the dynamic parameters associated to the segmental relaxation.
However the combination of dedicated set of samples with an experimental approach based on
relaxation spectroscopies (DRS, TMDC), microstructure investigation (WAXS, SAXS) and
Positron annihilation lifetime spectroscopy (PALS) enable to draw a clear picture of the
modifications occurring at different length scales.
REFERENCES
1. Delpouve, N.; Delbreilh, L.; Stoclet, G.; Saiter, A.; Dargent, E. Structural Dependence of the Molecular
Mobility in the Amorphous Fractions of Polylactide. Macromolecules 47 (15), 5186–5197 (2014)
2. Rijal, B.; Delbreilh, L.; Saiter, A. Dynamic Heterogeneity and Cooperative Length Scale at Dynamic Glass
Transition in Glass Forming Liquids. Macromolecules 48 (22), 8219–8231 (2015)
ORAL CONTRIBUTIONS Dyn-Hetero-9
Oral
Where Come from Dynamic Heterogeneity in Glass
Transition? : Similarity with Liquid-Liquid Transition
Y. Kajihara1, M. Inui
1 and A. Chiba
2
1Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8521, Japan
2Keio University, Yokohama, Kanagawa 223-8522, Japan
Where come from dynamic heterogeneity in glass-forming liquids? It is a long-standing
problem for glass transition phenomena1. In this presentation, we introduce our experimental
study about slow dynamics and a heterogeneity (inhomogeneity) induced in liquid-liquid (l-l)
transition, and discuss the relation between these two transitions.
Liquid Te and its mixtures with Se are famous systems to exhibit continuous l-l transition2,
whose similarity with liquid water is sometimes discussed3,4,5
. Se-Te also have a glass-
forming ability. The density inhomogeneity in the system is tiny but surely exists and shows
peak in the middle of the transition, which is first proved by our small-angle x-ray scattering
measurement4. About the dynamics, we deduce the relaxation intensity by sound velocity
measurements5 and observed that it varies in conjunction with the transition and also shows
peak. The relaxation time has not been investigated in detail, but at least is revealed to vary
much with temperature and exceeds over 10-9
s; there appears a slow dynamics6.
These experimental results for l-l transition recall the similarity to the dynamic heterogeneity
in glass transition, and in fact reminds us of a bold idea that the origin of the two phenomena
is same: Dynamical heterogeneity comes from the critical fluctuations of l-l transition not
from supercooling. Of course, there are not yet enough evidences for this scenario and it is
thus a speculation at the present stage. But we believe that it is worth to be discussed because
it can give a simple explanation to the fragility index of glass-forming liquids: How close is
the state to the critical pressure of l-l transition7. We look forward a frank discussion.
REFERENCES
1. Ediger, M. D., Ann. Rev. Phys. Chem. 51, 99 (2000)
2. Tsuchiya, Y.et al, J. Phys. C: Solid State Phys. 15, L687 (1982)
3. Angell, A., Nat. Nanotech. 2, 396 (2007)
4. Kajihara, Y.et al, Phys. Rev. B86, 214202 (2012)
5. Kajihara, Y. et al, J. Phys.: Condens. Matter 20, 494244 (2008); and in preparation
6. Yao, M. et al, J. Non-Cryst. Sol. 312-314, 361 (2002)
7. Kajihara, Y., Inui, M. and Chiba, A., “Simple scenario for glass transition phenomena based on liquid-liquid
transition framework”, 10th
Liquid Matter Conference (2017), Ljubljana, Slovenia
Dyn-Hetero-10 ORAL CONTRIBUTIONS
Oral
Probing dynamic lengthscales through coupling within the
potential energy landscape of supercooled liquids
Lawrence Smith , Carsten F. E. Schröer and Andreas Heuer
Institute of physical chemistry, Westfälische Wilhelms-Universität Münster, Corrensstr. 28/30
48149 Münster
Elementary units of a binary lennard-jones glassformer can be identified through quantitative
analysis of its underlying potential energy landscape. These units can be fully understood
within the continuous time random walk formalism and are found to contain the complete
information concerning thermodynamics and diffusivity, while displaying finite size effects
with respect to relaxation times and spacial correlations[1].
This work investigates the impact of coupling between the elementary units on these
correlations. By analysing multipoint dynamical susceptibilities and four point correlations
within the coupled landscape model and large molecular dynamics simulations, insight into
the relevant components of relaxation near the glass transition can be gained.
REFERENCES
1. Rehwald, C. and Heuer, A., How coupled elementary units determine the dynamics of macroscopic glass-
forming systems, Physical Review E 86, 051504 (2012).
ORAL CONTRIBUTIONS Gardner-1
Invited Talk
Solution of structural glass models in infinite dimensions
Pierfrancesco Urbani
Institut de physique théorique, Université Paris Saclay, CNRS, CEA, F-91191 Gif-Sur-Yvette
I will review the solution of structural glass models in infinite dimensions. I will show that in
some regions of the glass phase this solution predicts a new critical point: the Gardner
transition. This separates the normal glass phase from the marginal glass phase. I will
characterize the two phases and I will show that in the marginal phase, the system is predicted
to contain a lot of very soft excitations that can strongly affect its response to external
perturbations. I will discuss the physical consequences in various contexts: from the jamming
transition of hard spheres to the elastic behavior of low temperature amorphous solids.
REFERENCES
1. Charbonneau, P., Kurchan, J., Parisi, G., Urbani, P., Zamponi, F., Fractal free energy landscapes in
structural glasses, Nature Communications 5, 3725 (2014).
2. Biroli, G., Urbani, P., Breakdown of elasticity in amorphous solids, Nature Physics 12, 1130-1133 (2016).
3. Rainone, C., Urbani, P., Yoshino, H., Zamponi, F., Following the evolution of glassy states under external
perturbations: compression and shear strain, Physical Review Letters 114, 015701 (2015)
4. Franz, S., Parisi, G., Urbani, P., Zamponi, F., Universal spectrum of normal modes in low-temperature
glasses, Proceedings of the national academy of sciences 112, 47 14539-14544 (2015)
Gardner-2 ORAL CONTRIBUTIONS
Invited Talk
Dimensional robustness of replica symmetry breaking
Yaida, Sho1; Charbonneau, Patrick
1,2
(1) Department of Chemistry, Duke University, Durham, North Carolina 27708, USA;
(2) Department of Physics, Duke University, Durham, North Carolina 27708, USA
The transformation of the free-energy landscape from smooth to hierarchical is one of the
richest features of mean-field disordered systems. A well-studied example is the de Almeida-
Thouless transition for spin glasses in a magnetic field, and a similar phenomenon--the
Gardner transition--has recently been predicted for structural glasses. The existence of these
replica-symmetry-breaking phase transitions has, however, long been questioned below their
upper critical dimension, six. Here, we obtain evidence for the existence of these transitions in
physical dimensions, using a two-loop calculation. Because the critical fixed point is found in
the strong-coupling regime, we corroborate the result by resumming the perturbative series
with inputs from a three-loop calculation and an analysis of its large-order behavior. Our
study offers a resolution of the long-lasting controversy surrounding phase transitions in
finite-dimensional disordered systems.
REFERENCES
1. Charbonneau, P. & Yaida, S., Phys. Rev. Lett. in press (2017), arXiv:1607.04217.
ORAL CONTRIBUTIONS Gardner-3
Invited Talk
A unified study of plasticity, yielding, melting and jamming
in three-dimensional hard sphere glasses
Y. Jin1, H. Yoshino
1,2, P. Urbani
3, and F. Zamponi
4
1Cybermedia Center, Osaka University, Toyonaka, Osaka 560-0043, Japan
2Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
3IPhT, Université Paris Saclay, CNRS, CEA, F-91191 Gif-sur-Yvette, France
4LPT, ENS, UMR 8549 CNRS, 75005 Paris, France
For amorphous solids, it has been intensely debated whether the traditional view on solids, in
terms of the ground state and harmonic low energy excitations on top of it, such as phonons,
is still valid. Recent theoretical developments of amorphous solids revealed the possibility of
unexpectedly complex free energy landscapes where the simple harmonic picture breaks
down [1, 2]. Here we demonstrate that standard rheological techniques, i.e., shear protocols,
can be used as powerful tools to examine non-trivial consequences of such complex free
energy landscapes [3]. By extensive numerical simulations on a hard sphere glass under
quasi-static shear at finite temperatures, we show that, above the so-called Gardner transition
density, the elasticity breaks down, the stress relaxation exhibits slow and aging dynamics,
and the apparent shear modulus becomes protocol-dependent. We further obtain a
comprehensive phase diagram of the three-dimensional hard sphere glass under compression
annealing, decompression heating, and shearing. Our study establishes a unified framework of
plasticity, yielding, melting and jamming of simple amorphous solids, and provides deep
insights into the nature of these phenomena. Finally, we compare our numerical results to the
mean-field theoretical predictions [4], and discuss how to reproduce our approach in
experiments.
REFERENCES
1. Charbonneau, P., Kurchan, J., Parisi, G., Urbani, P., and Zamponi, F., Fractal free energy landscapes in
structural glasses, Nat. Commun. 5, 3725 (2014).
2. Berthier, L., Charbonneau, P., Jin, Y., Parisi, G., Seoane, B., and Zamponi, F., Growing timescales and
lengthscales characterizing vibrations of amorphous solids, PNAS 113, 8397 (2016).
3. Jin, Y.and Yoshino, H., Exploring the complex free-energy landscape of the simplest glass by rheology, Nat.
Commun. 8, 14935 (2017).
4. Urbani, P. and Zamponi, F., Shear yielding and shear jamming of dense hard sphere glasses, Phys. Rev.
Lett. 118, 038001 (2017).
Gardner-4 ORAL CONTRIBUTIONS
Oral
The Gardner Transition is not a Transition
C. L. Hicks, M.J. Wheatley, M. J. Godfrey and M. A. Moore
School of Physics & Astronomy, University of Manchester, Manchester M13 9PL, UK.
In infinite dimensions both the equilibrium and the state-following versions of the Gardner
transition are phase transitions. The field theory of these transitions is similar to that of the de
Almeida-Thouless transition in spin glasses, which is not thought to take place in any
dimension less than 6. Thus in dimensions two and three one would not expect there to be a
genuine Gardner transition, although remnants of it might arise as an avoided transition.
We have studied both the equilibrium version of the transition and the state-following version
for disks confined to move along a narrow channel, so our system is effectively one
dimensional and so cannot have any phase transition. From exact transfer matrix studies, we
find evidence that the equilibrium Gardner transition has become an avoided transition.
Molecular dynamics reveals that our one-dimensional system has nearly all the features
reported in two and three dimensions for the state-following version of the Gardner transition,
but it cannot, of course, be a genuine transition. For our system it is a simulational artifact: it
arises when the time scale of the quench becomes comparable to the relaxation times in our
system. Our system is sufficiently simple that we can identify precisely the relaxation
processes that freeze out on the timescale of the quench.
The glass transition temperature is defined as the point at which the relaxation times in the
glass are of order 10 minutes, which is a time whose significance is connected to human
lengths of patience, but nothing is really altering in the glass as its relaxational time scales
pass through 10 minutes. The state-following Gardner transition is similar. It is just a
consequence of the time scales used in quenches and system timescales.
ORAL CONTRIBUTIONS Gardner-5
Invited Talk
Dielectric Spectroscopy Below the Glass Temperature
Korbinian Geirhos, Peter Lunkenheimer, and Alois Loidl
Experimental Physics V, University Augsburg, Germany
The dynamics of glassy matter above the glass temperature (Tg) is already thoroughly studied
by dielectric spectroscopy in a broad frequency and temperature range. Dielectric data of
glasses below Tg, however, are rare. We present dielectric studies of type B glass formers
from Tg down to liquid helium temperature in a broad frequency range. The sub-Tg dielectric
response of these systems is governed by the Johari-Goldstein (JG) β-process, which shows
an enormous, continuously broadening with decreasing temperature. This temperature-
dependent broadening can qualitatively be explained by a simple Gaussian distribution of
energy barriers [1]. We also propose that the JG β-process provides a suitable tool for the
detection of the theoretically predicted Gardner transition in glass formers, since this process
is supposed to probe the local energy landscape within one metabasin [2] and at the Gardner
transition a fragmentation of this metabasin should take place [3]. Indeed, we find possible
indications for the Gardner transition in the temperature dependence of the broadening of the
JG β-process.
REFERENCES
1. Birge, N. O., Jeong, Y. H., Nagel S. R., Bhattacharya, S., Susman, S., Distribution of relaxation times in
(KBr)0.5(KCN)0.5, Phys. Rev. B. 30, 2306-2308 (1984).
2. Debenedetti, P., Stillinger, F., Supercooled liquids and the glass transition, Nature 410, 259-267 (2001).
3. Charbonneau, P., Kurchan, J., Parisi, G., Urbani, P., Zamponi, F., Fractal free energy landscape in structural
glasses, Nat. Commun. 5, 3725 (2014).
H-Pressure-1 ORAL CONTRIBUTIONS
Invited Talk
Vivid Manifestation of Nonergodicity in Glassy Propylene
Carbonate at High Pressures
V.V. Brazhkin, I.V. Danilov, E.L. Gromnitskaya
Institute for High Pressure Physics, 108840 Troitsk, Moscow, Russia
Since glasses are nonergodic systems, their properties should depend not only on the external
macroparameters (pressure and temperature), but also on the time of observation and on the
thermobaric history. In this work, comparative ultrasonic studies of two groups of molecular
propylene carbonate glasses obtained by quenching from a liquid at moderate pressures (0.05-
0.1 GPa) and high pressures (1GPa) have been performed for the first time. Although the
difference between the densities of different groups of glasses is small (3–4%), they have
significantly different elastic properties: difference between the respective bulk moduli is 10–
20% and difference between the respective shear moduli is 35–40% (!). The pressure and
temperature derivatives of the elastic moduli for these groups of glasses are also noticeably
different. The glass transition (softening) temperatures of glasses from different groups differ
by 3–4K. The character of absorption of ultrasound near the glass transition temperature also
differs for different groups of glasses. Difference in the behavior of these groups of glasses
disappears gradually above the glass transition temperature in the region of a liquid phase.
Glasses with a wide diversity of the physical properties can be obtained by using various
paths onto the (T,P) diagram.
ORAL CONTRIBUTIONS H-Pressure-2
Invited Talk
Nano- and macro-viscosity of van der Waals glass forming
liquids. Temperature and pressure dependent FCS study.
Agnieszka Połatynska1, Mikołaj Pochylski
1, Ewa Banachowicz
1, Gerd
Meier2, Jacek Gapinski
1,3, and Adam Patkowski
1,3
1Molecular Biophysics Division, Faculty of Physics, Adam Mickiewicz University, 61-614
Poznan, Poland
2Institute of Complex Systems, Soft Condensed Matter, Forschungszentrum Juelich, D-52425
Juelich, Germany
3NanoBioMedical Centre, Adam Mickiewicz University, 61-614 Poznan, Poland
Fluorescence correlation spectroscopy (FCS) is a single molecule method which allows to
measure the self (tracer) diffusion coefficient (DS) at extremely low concentrations (10-9
M)
of the fluorescent particle at as low sample volume as 50 l. From the values of DS the length
scale dependent nano-viscosity can be calculated using the Sokes-Einstein (SE) relation.
In order to perform the FCS measurements in a broad temperature (-20 to +150ºC) and
pressure (1-1000 bar) ranges new experimental setups and special sample cells were designed.
These cells in combination with a long working distance objective of the confocal microscope
were essential for avoiding temperature gradients in the sample and compensating the
spherical aberration introduced by thicker sample cell windows.
For selected molecular van der Waals glass forming liquids we show that in a broad
temperature and pressure ranges the nano-viscosity obtained from FCS experiment is in a
very good agreement with the macro-viscosity obtained from rheometry, despite the fact that
in these liquids a characteristic length scale and dynamic heterogeneity can be seen. Thus
FCS can be used to obtain the viscosity of supercooled liquids in a broad temperature and
pressure ranges.
REFERENCES
1. Banachowicz, E., Patkowski, A., Meier, G., Klamecka, K., and Gapinski, J., Successful FCS experiment in
nonstandard conditions, Langmuir 30, 8945−8955 (2014).
2. Deptuła, T., Buitenhuis, J., Jarzebski, M., Patkowski, A., and Gapinski, J., Size of Sub-micrometer Particles
Measured by FCS–Correction of the Confocal Volume,Langmuir 31, 6681–6687 (2015).
3. Połatynska, A., Tomczyk, K., Pochylski, M., Meier, M., Gapinski, J., Banachowicz, E., Śliwa, T.,
Patkowski, A., Temperature dependent FCS studies using a long working distance objective: viscosities of
supercooled liquids and particle size, J. Chem. Phys., 146, 084506 (1-9), (2017).
H-Pressure-3 ORAL CONTRIBUTIONS
Invited Talk
Isochronal study with combined neutron and dielectric
spectroscopy
Henriette Wase Hansen1, Alejandro Sanz
1, Karolina Adrjanowicz
2, Bernhard
Frick3 and Kristine Niss
1
1Glass & Time, IMFUFA, Department of Science and Environment, Roskilde University,
Denmark,
2Institute of Physics, University of Silesia, Katowice, Poland,
3Institut Laue-Langevin, Grenoble, France
We present a combined high-pressure cell for doing simultaneous dielectric spectroscopy and
neutron scattering in the range 1-300 K, 0.1-500 MPa. We study both the fast and slow
dynamics simultaneously in glass-forming liquids and are able to see signal with both
techniques. We follow the fast and slow dynamics along isobars, isotherms, and in particular
along isochrones, i.e. constant relaxation time τα ( T, P ).
We use the cell to test the isomorph theory. The fundamental prediction of the isomorph
theory is the existence of isomorphs, which are curves in the phase diagram along which all
dynamical phenomena and structure are invariant [1-6]. The alpha relaxation, both its time
and spectral shape, is one of the properties that is invariant along an isomorph, and we can
therefore experimentally identify the isomorphs by the isochrones. We thererfore expect to
see isochronal superposition along the isochrones, i.e. all types of spectra should collapse.
We explore the dynamics on a range of different timescales from picosecond to second
timescales, and show the difference between a van der Waals liquid and a H-bonded liquid on
along the glass transition isochrone, i.e. τα = 100 s, and higher temperature isochrones, all
found from dielectric spectroscopy.
REFERENCES
1. Gnan, N., et. al., J. Chem. Phys. 131, 234504 (2009).
2. Gnan, N., et. al., PRL 104, 125902 (2010).
3. Coslovich, D., et. al., J. Chem. Phys. 131, 151103 (2009).
4. Roed, L., et al. J. Chem. Phys. 139, 101101 (2013).
5. Xiao, W., et al. J. Non-Cryst. Solids 407, 190 (2015).
6. Gundermann, D., et al., Nature Physics 7, 816 (2011).
ORAL CONTRIBUTIONS H-Pressure-4
Invited Talk
High-Pressure Effects in Photovoltaic Hybrid Perovskites
Marek Szafrański
Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan, Poland
In recent years organic-inorganic hybrid perovskites of general formula MAPbX3 (where
MA = CH3NH3+, X = Cl
, Br
, I
) have emerged as highly efficient light-harvesting materials
for solar energy-conversion and other optoelectronic applications. The extremely quick
progress in the power-conversion efficiency of these materials,1 along with the ease and low-
cost of fabrication, strongly motivate further intense studies in this field.
The structures of lead halide perovskites are formed from corner-sharing octahedra and
organic cations situated within the cages, where the PbXPb edges of the cube-like
fragments are either straight or bent. The bond length and the angles between bonds in the
perovskite inorganic framework can be modified by high pressure without a chemical
interference and therefore this is a clean way of tuning electronic structure responsible for
basic photovoltaic features of the materials, like the energy gap and carrier diffusion length.
The high-pressure single-crystal X-ray diffraction experiments allowed us to obtain precise
information on the symmetry of phases and their stability regions, and on the changes in the
bond lengths and angles. These structural parameters have been correlated with the properties
relevant to the photovoltaic activity.2,3
In response to pressure the inorganic framework is
modified through the contraction of PbX bonds or/and bending of PbXPb bridges between
the PbX6 octahedra. The shortening of bonds PbX narrows the bandgap, whereas it is
widened by the PbXPb angle bending, but the resultant bandgap modification depends on
the contributions of these competitive pressure effects.
We also discovered new slow-kinetics processes of structural transformations, not observed in
other high-pressure experiments reported so far, which profoundly affect the optical
properties of MAPbCl3 and MAPbBr3 crystals. These findings are discussed in the context of
the possible origins of numerous considerable discrepancies between the high-pressure studies
reported in the literature.
REFERENCES
1. See https://www.nrel.gov/pv/assets/images/efficiency-chart.png, at National Renewable Laboratory, Best
Research-Cell Efficiencies. Accessed January 17, (2016).
2. Szafranski, M., Katrusiak, A. Mechanism of Pressure-Induced Phase Transitions, Amorphization, and Absorption-
Edge Shift in Photovoltaic Methylammonium Lead Iodide, J. Phys. Chem. Lett. 7, 3458–3466 (2016).
3. Szafranski, M., Katrusiak, Photovoltaic Hybrid Perovskites under Pressure, J. Phys. Chem. Lett. (2017-
submitted).
H-Pressure-5 ORAL CONTRIBUTIONS
Oral
Molecular Simulations of Shock Mechanics for Semi-
crystalline Polyethylene
Timothy Sirk, Robert Elder, Jan Andzelm
U.S. Army Research Laboratory
Semi-crystalline polyethylene (PE) is used in a variety of mechanically demanding
applications where shock compression can occur [1]. Although highly crystalline, nanoscale
amorphous domains in the semi-crystalline structure influence shock propagation and
attenuation. To study the effects of such domains, we have parameterized a simple
continuum-level theory based on the shock impedance from molecular dynamics (MD)
simulations. Using this approach, we predict how crystalline/amorphous interfaces attenuate
shocks via energy reflection due to the impedance mismatch between the phases, finding that
these interfaces attenuate weak shocks more effectively than strong shocks. These
calculations are compared to explicit non-equilibrium MD simulations of compressive shocks
in semi-crystalline PE containing nanometer-scale amorphous regions of varying size. The
theory and simulations show good agreement for strong shocks, but for weak shocks the
simulations show greatly enhanced energy reflection. Further, a dependence on the size of
amorphous regions is shown. The continuum calculations assume a sharp discontinuous
interface between two bulk phases and a sharp change in thermodynamic and hydrodynamic
quantities at the shock front. In contrast, the simulations show that, as amorphous domains are
narrowed to a width comparable to the shock front, the reflection wave is greatly reduced. We
identify several nanoscale mechanisms that reduce the impedance mismatch in thin
amorphous domains, including confinement effects from the surrounding stiff ordered
crystalline domains, the two-wave elastic-plastic structure of shocks in crystalline PE which
allows the faster-moving elastic wave to compress small amorphous domains before the
plastic wave arrives, and a broadening of the shock front as the shock strength is reduced.
These results are intended to inform strategies to enhance shock attenuation in semi-
crystalline materials.
REFERENCES
1. Kim, J., Heckert, N., Kang, K., McDonough, W., Rice, K., Holmes G., Statistical Characterizations for
Tensile Properties of Co-polymer Aramid Fibers: Loading Rate Effects. Dynamic Behavior of
Materials.1, 69-73 (2016).
ORAL CONTRIBUTIONS IonLiq-Polym-1
Invited Talk
Solvation Dynamics and Reactivity of Pre-Solvated
Electrons in Ionic Liquids
James F. Wishart, Andrew R. Cook
Chemistry Division, Brookhaven National Laboratory, Upton, NY 11973 USA
Ionic liquids (ILs) have dramatically different properties compared to conventional molecular
solvents, and they provide a new and unusual environment to test our theoretical
understanding of primary radiation chemistry, charge transfer and other reactions. We are
interested in how IL properties influence physical and dynamical processes that determine the
stability and lifetimes of reactive intermediates and thereby affect the courses of reactions and
product distributions, for example the competition between electron solvation dynamics and
the scavenging of electrons in different states of solvation. Pre-solvated electron scavenging is
especially significant in ionic liquids because their relatively high viscosities make their
solvation dynamics 100-1000x slower than in conventional solvents. Pre-solvated electrons
are more mobile and show different reactivity patterns than solvated ones. The slower
relaxation dynamics of ILs make them excellent media for the general study of fundamental
radiolysis processes, in combination with BNL’s Laser-Electron Accelerator Facility (LEAF)
and its Optical Fiber Single-Shot (OFSS) optical detection technique [1]. Using OFSS, we can
observe the solvation processes of radiolytically-generated excess electrons and compare and
contrast them with the mechanisms of pre-solvated electron scavenging, as demonstrated in
an earlier publication [2]. Results will be presented for a wide variety of scavengers (e.g.,
nitrate, benzophenone) that show different reaction profiles towards the various precursor
states to the solvated electron, in ILs of widely different viscosities and dynamics. This work
was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy
Sciences, Division of Chemical Sciences, Geosciences and Biosciences, under contract DE-
SC0012704.
REFERENCES
1. Cook, A. R., Shen, Y. Z., Optical Fiber-Based Single-Shot Picosecond Transient Absorption Spectroscopy,
Rev. Sci. Instrum., 80, 073106 (2009).
2. Wishart, J. F., Funston, A. M., Szreder, T., Cook, A. R., Gohdo, M., Electron solvation dynamics and
reactivity in ionic liquids observed by picosecond radiolysis techniques, Faraday Discuss. 154, 353-363
(2012).
IonLiq-Polym-2 ORAL CONTRIBUTIONS
Invited Talk
Insight from molecular dynamics simulations into
structural and dynamic correlations operative in energy
storage devices.
Dmitry Bedrova, Jenel Vatamanu
b, Dengpan Dong
a
a Department of Materials Science & Engineering, University of Utah, Salt Lake City, Utah,
84112, USA
b Electrochemistry Branch, Sensors and Electron Devices Directorate, Army Research
Laboratory, 2800 Powder Mill Rd., Adelphi, MD, 20703, USA
Ionic liquids and their solutions are extensively considered as promising novel electrolytes for
applications in batteries, supercapacitors and other energy storage/conversion devices.
However, the complex interplay between the molecular scale structure and dynamic
correlations in bulk electrolytes and near charged electrode surfaces as well as how these
correlations can affect the device performance require further comprehension and
understanding. In this talk, we will discuss how the molecular scale simulations can provide a
valuable insight into understanding the mechanisms and correlations of ion motion in various
environments. Specifically, we will focus on a) key challenges that molecular simulation
methods are facing in such problems and possible routes to overcome such challenges, b) the
latest results from simulations of ionic liquids and their mixtures near charged surfaces and
inside nanoporous electrodes, and c) the mechanisms of Li+ mobility in pure RTIL and mixed
RTIL/organic solvent electrolytes as well as in bulk phases of a model solid electrolyte
interfaces (SEI).
ORAL CONTRIBUTIONS IonLiq-Polym-3
Invited Talk
Mechanism and Dynamics of CO2 Capture in 1-Alkyl-3-
methylimidazolium Acetate
Fangyong Yan,1 Nilesh R. Dhumal
1 and Hyung J. Kim
1,2
1Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA 15213, USA
2School of Computational Sciences, Korea Institute for Advanced Study, Seoul 02455, Korea
Ionic liquids provide a promising medium for CO2 capture. Recently, it was found that the
family of ionic liquids comprising 1-alkyl-3-alkyl’-imidazolium cations and acetate anions,
such as 1-ethyl-3-methylimidazolium acetate (EMI+OAc
–), react with CO2 and form
carboxylate compounds. It is widely assumed that N-heterocyclic carbene (NHC) is
responsible by directly reacting with CO2. However, this is controversial in that NHC has not
been detected experimentally in this family of ionic liquids though it was found in their
vapors. In this presentation, we address this issue by presenting our recent computational
study of CO2 capture in EMI+OAc
–. Quantum chemistry calculations performed using the
self-consistent reaction field theory predict that NHC becomes unstable in solution as the
solvent polarity increases, suggesting that NHC is not formed in EMI+OAc
–. Ab initio
molecular dynamics simulation results obtained using the constrained dynamics method
indicate that an EMI+ ion activated by the approach of a CO2 molecule can donate its acidic
proton to a neighboring OAc– anion and rapidly form a carboxylate compound with the CO2
molecule. Based on these findings, a novel concerted mechanism that does not involve NHC
is proposed for CO2 capture.1 Its implications for other reactions in the 1-alkyl-3-alkyl’-
imidazolium acetate ionic liquid family are briefly discussed.
REFERENCES
1. Yan, F., Dhumal, N. R., Kim, H. J., CO2 capture in ionic liquid 1-alkyl-3-methylimidazolium acetate: A
concerted mechanism without carbene, Phys.Chem.Chem.Phys. 19, 1361–1368 (2017).
IonLiq-Polym-4 ORAL CONTRIBUTIONS
Invited Talk
Room Temperature Ionic Liquids: Force Field Development
and Applications as Electrolytes and Biomolecular
Dissolution
Balasubramanian Sundaram
Chemistry & Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific
Research, Jakkur, Bengaluru 560064, India
While a scaling of ion charge in the force fields of room temperature ionic liquids (IL) have
been shown to improve the comparison of IL dynamics with experiments, until now the scale
factor has been chosen in somewhat an ad hoc manner. We show that such a scale factor can
be 'derived' from ab initio calculations of bulk phases of ILs, which also depends on the
nature of the cation and the anion constituting the liquid. Non-polarizable Force fields derived
from such an approach using effective charges are able to predict quantitatively many
physical properties in quantitative agreement with experiments for not only neat liquids but
also for their mixtures.
The nature of ion and proton transport in protic organic ionic plastic crystals investigated via
classical and ab initio MD simulations will also be presented. The interfacial activation of
lipases in amino acid based IL as a function of its concentration, as studied using MD
simulations will be discussed.
REFERENCES
1. Das, S., Mondal, A., Balasubramanian, S., Recent advances in modeling green solvents, Curr. Opin. Green
Sust. Chem. DOI: 10.1016/j.cogsc.2017.03.006 (2017).
2. Mondal, A., Balasubramanian, S., Quantitative prediction of physical properties of imidazolium based room
temperature ionic liquids through determination of condensed phase site charges: A refined force field, J.
Phys. Chem. B 118, 3409-3422 (2014).
3. Mondal, A., Balasubramanian, S., A molecular dynamics study of collective transport properties of
imidazolium based room temperature ionic liquids, J. Chem. Eng. Data, 59, 3061-3068 (2014).
4. Mondal, A., Balasubramanian, S., A refined all-atom potential for imidazolium based room temperature
ionic liquids: Acetate, dicyanamide and thiocyanate anions, J. Phys. Chem. B, 119, 11041-11051 (2015).
5. Mondal, A., Sunda, A., Balasubramanian, S., Thermal phase behavior and ion hopping in 1,2,4-triazolium
perfluorobutanesulfonate protic organic ionic plastic crystal, Phys. Chem. Chem. Phys., 18, 2047-2053
(2016).
6. Mondal, A., Balasubramanian S., Proton hopping mechanism in a protic organic ionic plastic crystal, J.
Phys. Chem. B, 120, 22903-22909 (2016).
7. Das, S., Karmakar, T., Balasubramanian, S., Molecular mechanism behind solvent concentration-dependent
activity of thermomyces lanuginosus lipase in a biocompatible ionic liquid: Interfacial activation through
arginine switch, J. Phys. Chem. B, 120, 11720-11732 (2016).
ORAL CONTRIBUTIONS IonLiq-Polym-5
Invited Talk
Ion structure and transport in ionic liquid electrolytes; the
effect of ultra-high concentration of alkali metal salts on
decoupling of Li+ /Na
+ conduction.
M.Forsyth1, P.C.Howlett
1, F.Chen
1 and D.R.MacFarlane
2
1 Institute for Frontier Materials and Australian Centre of Excellence in Electromaterials
Science, Deakin University, Victoria, Australia
2 School of Chemistry and Australian Centre of Excellence in Electromaterials Science,
Monash University, Victoria, Australia
It has recently been shown, in the case of the bisfluorosulfonamide (FSI) based ionic liquids,
that as the concentration of the alkali metal salt (LiFSI or NaFSI) is increased, the alkali metal
cation transference number increases, despite an increase in viscosity and decrease in
conductivity.1 At the same time significant enhancements in electrochemical stability and rate
performance of devices are also observed. With increasing alkali metal salt concentration
towards a 1:1 mixture, the available FSI anions required to satisfy the coordination
environment of the alkali metal cation (between 3 and 5) will become fewer and insufficient
unless each anion begins to coordinate more than one metal cation, for example by bridging
two or even three Li+ or Na
+ ions. This would result in significant aggregation and structuring
of the ionic liquid as observed via our MD simulations as seen in Figure 1. The Li+ or Na
+
ion transport mechanism at these high concentrations appears to be dominated by a structural
diffusion process reminiscent of the Grotthus mechanism observed in proton conductors and
essentially is decoupled from the bulk viscosity of the ionic liquid.
References
1. Forsyth, M., Girard, G.M.A., Basile, A., Hilder, M., MacFarlane, D.R., Chen, F., Howlett, P.C.,
Electrochimica Acta 220, 609–617 (2016).
IonLiq-Polym-6 ORAL CONTRIBUTIONS
Invited Talk
Solvation Heterogeneity of Ionic Liquids Viewed from
Translational and Rotational Dynamics of Solutes
KIMURA, Yoshifumi
Department of Applied Chemistry, Graduate School of Science and Engineering, Doshisha
University, Kyotanabe 610-0321, Japan
Translational and rotational dynamics of small molecules such as carbon monoxide (CO) and
carbon dioxide (CO2) in ionic liquids (ILs) show unique behavior different from those
observed for larger neutral molecules of which sizes are similar to solvent cations or anions.
For example, the translational diffusion coefficients of CO in ILs are much faster than those
predicted from the hydrodynamic theory[1]. We have studied translational diffusion
coefficients of CO in various ILs by the transient grating spectroscopy in details, and found
that the translational diffusion coefficients of CO in ILs with cations of long alkyl-chains such
as tributylmethylphosphonium cation and tetraoctylmethylphosphonium cation are faster than
the values estimated from the correlations observed in other ILs with shorter alkyl chains[2].
Quite similar dependence was observed for the rotational correlation time of CO determined
by the T1 measurement of 17
O-NMR of 17
O-labeled CO[3]. More interestingly, the rotational
relaxation times of CO in ILs with long alkyl-chains are similar to those in alkane solvents
with similar number of alkyl-carbon if compared at the same T/, where T is the absolute
temperature is the viscosity of the solvent. The dependence on T/ is similar between the
translational diffusion coefficients and rotational relaxation rate in the same IL. The alkyl-
chain length dependence of the rotational relaxation time is also evident for CO2, which is
slightly larger than CO. The comparison with larger molecules is currently under
investigation.
REFERENCES
1. Nishiyama, Y., Fukuda, M., Terazima, M., Kimura, Y., Study of translational diffusion of benzophenone
ketyl radical in comparison with stable molecules in room temperature ionic liquids by the transient grating
spectroscopy, J. Chem. Phys. 128, 164514(1-9) (2008).
2. Kimura, Y., Kida, Y., Matsushita, Y., Yasaka, Y., Ueno, M., Takahashi, K., Universality of Viscosity
Dependence of Translational Diffusion Coefficients of Carbon Monoxide, Diphenylacetylene, and
Diphenylcyclopropenone in Ionic Liquids under Various Conditions, J. Phys. Chem. B, 119, 8096-8103
(2015).
3. Yasaka, Y., Kimura, Y.; Polarity and Nonpolarity of Ionic Liquids Viewed from the Rotational Dynamics of
Carbon Monoxide, J. Phys. Chem. B, 119, 8096-8103 (2015).
4. Yasaka, Y., Kimura, Y., Rotational dynamics of carbon dioxide in ionic liquids, J. Mol. Liq. 226 43–47
(2017).
ORAL CONTRIBUTIONS IonLiq-Polym-7
Invited Talk
Singlet oxygen phosphorescence as a probe for voids in
ionic liquids
Tsuyoshi Yoshida1, Naoya Ishiwata
1, and Akio Kawai
1,2
1Tokyo Institute of Technology, Ohokayama, Meguro-ku, Tokyo 152-8551, Japan
2Kanagawa University, Tsuchiya 2946, Hiratsuka-shi, Kanagawa 259-1293, Japan
Void structure is one of important physicochemical properties of ionic liquids and is related
to diffusion, solubility and solvation of small solute molecules.1,2
Solvation dynamics in ionic
liquids have been investigated by measuring fluorescence of dye molecules, which are rather
large solute as compared to voids in ionic liquids. We have used smaller probe of nitroxide
radicals in ESR spectroscopy for solute dynamics, and found their slipping rotation in ionic
liquids.3 But, a size of the probe is still larger than that of voids. In the present study, we
introduce a probe molecule of O2 that is small enough to probe voids in ionic liquids.
The first electronic excited state of O2, a1g state, is known to give weak phosphorescence of
a1g→X
3g optical transition in near IR wavelength region.
4,5 According to spectral
measurements of O2(a1g), it was found that the luminescence shows simple single peak at
1270 nm with small solvatochromic shift depending on anion size of ionic liquids. This
solvatochromic shift was explained by introducing a mean distance between O2 probe
molecule and solvent, that is controlled by size of voids in ionic liquids.
We will mention near IR spectroscopy for O2(a1g) phosphorescence and our procedure to
estimate size of voids in polar and non-polar domains, and then, argue void structure in polar
domain of ionic liquids that accommodate O2 molecules.
REFERENCES
1. Morgan, D, Ferguson, L. and Scovazzo, P., J. Phys. Chem. Res. 44, 4815-4823 (2005).
2. Klahn, M. and Seduraman, A., J. Phys. Chem. B. 119, 10066-10078 (2015).
3. Schweitzer C., and Schmidt, L., Chem. Rev. 103, 1685-1757 (2003).
4. Miyake, Y., Akai, N., Kawai, A., Shibuya, K., Hydrodynamic interpretation on the rotational diffusion of
peroxylamine disulfonate solute dissolved in room temperature ionic liquids as studied by electron
paramagnetic resonance spectroscopy, J.Phys.Chem. A, 115, 6347-6356 (2011).
5. Yoshida, T., Kawai, A., Khara, D.C., Samanta, A., Temporal Behavior of the Singlet Molecular Oxygen
Emission in Imidazolium and Morpholinium Ionic Liquids and Its Implications, J.Phys.Chem. B, 119, 6696-
6702 (2015).
IonLiq-Polym-8 ORAL CONTRIBUTIONS
Oral
Charge Transport and Molecular Dynamics in highly
conductive Polymeric Ionic Liquids
Falk Frenzel
Leipzig University, Peter Debye Institute for Soft Matter Physics, Linnèstraße 5, 04103
Leipzig, Germany
Glassy dynamics and charge transport are studied for the polymeric Ionic Liquid (PIL)
poly[tris(2-(2-methoxyethoxy)ethyl)ammonium acryloxypropyl-sulfonate] (PAAPS) with
varying molecular weight (9700, 44200, 51600 and 99500 g/mol) by Broadband Dielectric
Spectroscopy (BDS) in a wide frequency (10-2
- 107 Hz) and temperature range (100 - 400 K)
and by DSC- and AC-chip calorimetry. The dielectric spectra are characterized by a
superposition of (i) relaxation processes, (ii) charge transport and (iii) electrode polarization.
The relaxation processes (i) are assigned to the dynamic glass transition and a secondary
relaxation. Charge transport (ii) can be described by the random free-energy barrier model as
worked out by Dyre et al.; the Barton-Namikawa-Nakajima (BNN) relationship is well
fulfilled over more than 8 decades. Electrode polarization (iii) follows the characteristics as
analyzed by Serghei et al.; with deviations on the low frequency side. The proportionality
between the relaxation rate of the dynamic glass transition and the charge carrier hopping rate
reflects the nature of charge transport as glass transition assisted hopping. Hereby, the PIL
under study exposes the highest dc-conductivity values observed for this class of materials
below 100°C, so far; and for the first time a conductivity increase by rising degree of
polymerization. The comparison of the polymeric Ionic Liquids under study with others
implies conclusions on the design of novel highly conductive PILs.
REFERENCES
1. Frenzel, F., Guterman, R., Anton, A. M., Yuan, J., Kremer, F., Molecular Dynamics and Charge Transport
in highly conductive Polymeric Ionic Liquids, Macromolecules. (2017-submitted)
ORAL CONTRIBUTIONS IonLiq-Polym-9
Invited Talk
The Surface Force Balance – Investigation of Ionic Liquids
under Confinement
M. Balabajew1, A.M. Smith
1,2, C. Perez-Martinez
1, C.D. van Engers
1, S.
Perkin1
1 Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of
Oxford, Oxford, UK
2 Department of Inorganic and Analytical Chemistry, University of Geneva, Geneva, CHE
Ionic liquids in micro- and nano-confinement are of fundamental interest in numerous
technological applications from lubrication to energy storage. Nevertheless, many basic
interfacial processes and properties such as friction, interfacial structure and double layer
formation are still not well understood. The surface force balance (SFB) allows for measuring
normal forces and shear forces between two smooth identical surfaces, traditionally mica
surfaces, in crossed-cylinder configuration (see Fig. 1). The absolute distance between the
surfaces is measured by means of white light interferometry with a resolution of approx. 1
Å.By using the SFB we gained valuable insight into the interfacial structure,1 electrostatic
screening lengths2 and friction
3 of different ionic liquids confined between two mica surfaces.
Furthermore, we further developed the technique to replace mica by graphene.4 This allows us
to study ionic liquids in a model system of a single slit pore of carbonaceous material and also
apply electrical potentials to the confined ionic liquid.
REFERENCES
1. Smith, A.M., Lee, A., Perkin, S., Switching the Structural Force in Ionic Liquid-Solvent Mixtures by
Varying Composition, Phys. Rev. Lett. 118, 096002 (2017).
2. Smith, A.M., Lee, A., Perkin, S., The Electrostatic Screening Length in Concentrated Electrolytes Increases
with Concentration, J. Phys. Chem. Lett. 7, 2157-2163 (2016).
3. Smith, A.M., Lovelock, K.R.J., Gosvami, N.N., Welton, T., Perkin, S., Quantized friction across ionic liquid
thin films, Phys. Chem. Chem. Phys. 15, 15317-15320 (2013).
4. Britton, J., Cousens, N.E.A, Coles, S.W., Van Engers, C.D., Babenko, V., Murdock, A.T., Koos, A., Perkin,
S., Grobert, N., A Graphene Surface Force Balance, Langmuir 30, 11485-11492 (2014).
IonLiq-Polym-10 ORAL CONTRIBUTIONS
Oral
The Physics of Ionic Liquids near Graphene Interfaces;
New Insights from Molecular Dynamics Simulations
Srđan Begić, Erlendur Jónsson, Fangfang Chen, Maria Forsyth
ARC Centre of Excellence for Electromaterials Science (ACES)
Institute for Frontier Materials
Deakin University, Burwood Campus
Burwood, VIC 3175, Australia
Two ionic liquids (ILs), N-butyl-N-methylpyrrolidinium dicyanamide ([C4mpyr][dca]) and 1-
ethyl-3-methylimidazolium dicyanamide ([C2mim][dca]), were previously demonstrated as
electrolytes in an experimental rechargeable zinc battery system1. However, in cyclic
voltammetry tests it was shown that the imidazolium-based system outperformed the
pyrrolidinium system despite the fact that the measured physicochemical properties of the two
systems were similar. Following up on those results, we recently used Atomic Force
Microscopy (AFM) to show that the two zinc systems feature a marked difference in their
interfacial layering capability2, with the imidazolium system showing a much-reduced ability
to layer compared to the pyrrolidinium at almost all of the tested conditions.
In the present study we use molecular dynamics simulations and show that the two ILs exhibit
significantly different layering behaviour near a graphene interface – in support of the AFM
findings, as well as a largely different 2D configuration and 3D orientation of the ions in the
inner layer. These results indicate that differences in the IL interfacial nanostructures may be
responsible for the large differences in the electrochemistry observed experimentally.
Additionally, we show that the size of the simulated system may play a much more important
role on the relaxation mechanics of IL simulations than previously thought, especially in light
of some recent experimental and theoretical developments.
REFERENCES
1. Simons, T. J., Macfarlane, D. R., Forsyth, M. & Howlett, P. C., Zn Electrochemistry in 1-Ethyl-3-
Methylimidazolium and N-Butyl-N-Methylpyrrolidinium Dicyanamides: Promising New Rechargeable Zn
Battery Electrolytes, ChemElectroChem, 1, 1688-1697 (2014).
2. Begić, S., Li, H., Atkin, R., Hollenkamp, A. F. & Howlett, P. C., A comparative AFM study of the
interfacial nanostructure in imidazolium or pyrrolidinium ionic liquid electrolytes for zinc electrochemical
systems, Physical Chemistry Chemical Physics. 18, 29337-29347 (2016).
ORAL CONTRIBUTIONS IonLiq-Polym-11
Invited Talk
Long-Range Charge Order and Electrostatic Screening in
Ionic Liquids and Concentrated Electrolyte Solutions
Anna Gubarevich and Junko Habasaki
Tokyo Institute of Technology, Japan
Stable colloidal solutions of diamond nanoparticles in an ionic liquid have been obtained and
described in our previous work [1]. Other nanoparticles have also been found to form stable
colloids with ionic liquids [2]. Such ability of ionic liquids to effectively disperse various
nanoparticles deserves attention, since the mechanism of interaction between nanoparticles
and ionic liquids is not so evident. In the field of colloidal science to describe stability of
colloidal suspensions in aqueous electrolyte solutions, the DLVO theory, which formulates
interplay between attractive van der Waals forces and repulsive electrostatic forces, is widely
used. However, this theory can be hardly applied for ionic liquids, because of their high ionic
strength and as a result short calculated electrostatic charge screening lengths. From the other
side, recent measurements of the interaction force between two surfaces immersed in an ionic
liquid have demonstrated the presence of long-range electrostatic effects in the ionic liquids,
which molecular origin represents a topic of an active discussion [3].
A long-range charge order in ionic liquids may considerably affect stability of nanoparticles
in ionic liquids, therefore in the present work we performed molecular dynamics simulations
to evaluate long-range charge order and electrostatic charge screening lengths in ionic liquids
and concentrated electrolyte solutions. Concentrated electrolyte solutions are considered to
approach ionic liquids in an utmost case. Changes in ionic interactions and correlation length
of the radial charge distribution function for aqueous solutions of sodium chloride were
studied in a wide concentration range. Development of ionic network with increasing
concentration was observed. Connection between long-range charge order and stability of
nanoparticles in ionic liquids will be discussed.
REFERENCES
1. Gubarevich, A., Habasaki, J., Odwara, O., Colloidal Stability of Diamond Nanoparticles in an Ionic Liquid,
7th
IDMRCS (2013).
2. Zhang, H., Dasbiswas, K., Ludwig, N.B., Han, G., Lee, B., Vaikuntanathan, S., Talapin, D.V., Stable
colloids in molten inorganic salts, Nature 542, 328-331 (2017).
3. Gebbie, M.A., Smith, A.M., Dobbs, H.A., Lee, A.A., Warr, G.G., Bankuy, X., Valtiner, M., Rutland, M.W.,
Israelachvili, J.N., Perkin, S., Atkin, R., Long Range Electrostatic Forces in Ionic Liquids, Chem. Commun.
53, 1214-1224 (2017).
IonLiq-Polym-12 ORAL CONTRIBUTIONS
Invited Talk
Ionic Liquids as Cnidaria:
From hydrotropy to surface activity
José N. Canongia Lopes , Karina Shimizu
Centro de Química Estrutural, Instituto Superior Técnico, Universidade e Lisboa
The title of this presentation is based on the notion that ionic liquids in solution will adapt
their bulk nano-segregated nature to different media conditions. Two types of situations will
be considered: hydrotropy and surfactant effects. The analogy between ionic liquids and
animals from the Cnidaria animal phylum will be apparent throughout the presentation.
Hydrotropes are compounds able to enhance the solubility of hydrophobic substances in
aqueous media and therefore are widely used in the formulation of drugs, cleaning and
personal care products. In this presentation, it is shown that ionic liquids are a new class of
powerful catanionic hydrotropes where both the cation and the anion synergistically
contribute to increase the solubility of biomolecules in water. Molecular Dynamics
simulations are used to explain the molecular mechanisms responsible for the strong
hydrotrope effects exhibited by the studied ionic liquids.
On the other hand, the surfactant behavior of two tetra-alkylphosphonium-based ionic liquids
at the water-air interface is also considered using Langmuir trough technique data and MD
simulations. The numerical density profiles obtained from the MD simulation trajectories are
also able to emphasize the very unusual packing of the four long alkyl side chains of the
cation above and below the ionic layer that forms at the water surface. Such a distribution is
also different for the two studied systems during the different compression regimes.
REFERENCES
1. Cláudio, A. F. M., Neves, M. C., Shimizu, K., Canongia Lopes, J. N., Freire, M. G., Coutinho, J. A. P., The
Magic of aqueous solutions of ionic liquids: ionic liquids as a powerful class of catanionic hydrotropes,
Green Chemistry. 17, 3948-3963 (2015).
2. Shimizu, K., Canongia Lopes, J. N., Gonçalves da Silva, A. M. P. S., Ionic Liquids at the Water-Air
Interface: Langmuir Isotherms of Tetra-alkylphosphonium-Based Ionic Liquids, Langmuir. 31, 8371-8378
(2015).
ORAL CONTRIBUTIONS IonLiq-Polym-13
Invited Talk
Evidences of fluorous mesoscopic domains in room
temperature ionic liquids
Alessandro Trioloa, Fabrizio Lo Celso
b and Olga Russina
c
a ISM-CNR, Rome, Italy;
b Dept-Phys. & Chem. University of Palermo, Italy;
c Dept. of
Chemistry, University of Rome Sapienza, Rome, Italy
Room temperature ionic liquids (RTILs) represent a stimulating class of compounds with
appealing performances in a range of fields. In the last few years several reports focused on
the interesting properties of fluorinated RTILs. This class of ILs finds application in
separation, pharmacology, catalysis etc and as such is receiving growing attention from the
community. Among the relevant properties highlighted in FRTILs, the possibility that
fluorous moieties might segregate analogously to their alkyl counterparts in conventional
RTILs has been proposed [1–6]. So far however, no direct experimental evidence for such a
behavior has been provided.
Here we provide the first direct experimental evidence that RTILs bearing a long enough side
fluorous chain are characterized by the existence of a distinct mesoscopic organization,
associated with the segregation of the fluorous tails. [7] By taking advantage of the synergy
between x-ray and neutron scattering coupled with state of the art Molecular Dynamics
simulations, we will discuss several consistent examples where such a phenomenology has
been observed.
REFERENCES
1. Pereiro, A.B. et al.: On the Formation of a Third, Nanostructured Domain in Ionic Liquids. J. Phys. Chem.
B. 117, 10826–10833 (2013).
2. Shen, Y. et al.: Protic ionic liquids with fluorous anions: physicochemical properties and self-assembly
nanostructure. Phys. Chem. Chem. Phys. 14, 7981–92 (2012).
3. Hettige, J.J., Araque, J.C., Margulis, C.J.: Bicontinuity and multiple length scale ordering in triphilic
hydrogen-bonding ionic liquids. J. Phys. Chem. B. 118, 12706–16 (2014).
4. Russina, O. et al.: Mesoscopic structural organization in triphilic room temperature ionic liquids. Faraday
Discuss. 167, 499 (2013).
5. Vieira, N.S.M. et al.: A thermophysical and structural characterization of ionic liquids with alkyl and
perfluoroalkyl side chains. RSC Adv. 5, 65337–65350 (2015).
6. Ferreira, M.L. et al.: Influence of Nanosegregation on the Phase Behavior of Fluorinated Ionic Liquids. J.
Phys. Chem. C. 121, 5415–5427 (2017).
7. Lo Celso, F. et al: Direct Experimental Observation of Mesoscopic Fluorous Domains in Fluorinated Room
Temperature Ionic Liquids. Phys. Chem. Chem. Phys. (2017).
IonLiq-Polym-14 ORAL CONTRIBUTIONS
Invited Talk
Thermodynamic and Neutron Scattering Studies on Glass
Transitions and Related Dynamics in Ionic Liquids
Osamu Yamamuro1 and Maiko Kofu
1,2
1 Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
2 Materials and Life Science Division, J-PARC Center, Tokai, Ibaraki 319-1195, Japan
Ionic liquid (IL) may be the most popular subject in current liquid science. We have studied
the structures and dynamics of ILs by means of calorimetric and various neutron scattering
techniques [1-6]. In this meeting, we will review our works especially focusing on the glass
transitions and related microscopic dynamics. Our target is the most typical IL that is
alkylmethylimidazolium salts abbreviated as CnmimX (n: alkyl carbon number, X: anion).
We have measured the heat capacities and quasielastic neutron scattering (QENS) of
CnmimX (n = 2, 3, 4, 6, 8, X = Cl, I, NO3, FeCl4, PF6, TF, FSI, TFSI); all of the cation/anion
combinations have not been covered. Most of the measured samples exhibit glass transitions
with large Cp jumps in a temperature range between 170 K and 230 K. The large Cp jumps
imply that these ILs are fragile liquids that exhibit large structural change depending on
temperature. The glass transition temperature Tg does not depend much on n but on the size of
anions. The QENS data revealed that the ionic diffusion is directly associated with the
viscosity and glass transition. The n and anion dependences of the activation energy for the
ionic diffusion were perfectly consistent with those of Tg. These results can be explained well
by taking account the nano-domain structure which is the most characteristic feature of
imidazolium-based ILs.
REFERENCES
1. Kofu, M., Tyagi, M., Inamura, Y., Miyazaki, K., Yamamuro, O., Quasielastic neutron scattering studies on
glass-forming ionic liquids with imidazolium cations, J. Chem. Phys., 143, 234502 (2015).
2. Kofu, M., Inamura, Y., Moriya, Y., Podlesnyak, A., Ehlers, G., Yamamuro, O., Inelastic neutron scattering
study on boson peaks of imidazolium-based ionic liquids, J. Mol. Liq, 210, 164 (2015).
3. Nemoto, F., Kofu, M., Yamamuro, O., Thermal and Structural Studies of Imidazolium-Based Ionic Liquids
with and without Liquid-Crystalline Phases: The Origin of Nanostructure, J. Phys. Chem. B, 119, 5028
(2015).
4. Kofu, M., Nagao, M., Ueki, T., Kitazawa, Y., Nakamura, Y., Sawamura, S., Watanabe, M., Yamamuro, O.,
Heterogeneous Slow Dynamics of Imidazolium Based Ionic Liquids Studied by Neutron Spin Echo, J. Phys.
Chem. B, 117, 2773 (2013).
5. Yamamuro, O., Yamada, T., Kofu, M., Nakakoshi, M., Nagao, M., Hierarchical Structure and Dynamics of
an Ionic Liquid 1-Octyl-3-methyl-imidazolium Chloride, J. Chem. Phys., 135, 054508 (2011).
6. Yamamuro, O., Minamimoto, Y., Inamura, Y., Hayashi, S., Hamaguchi, H., Heat capacity and glass
transition of an ionic liquid 1-butyl-3-methylimidazolium chloride, Chem. Phys. Lett., 423, 371 (2006).
ORAL CONTRIBUTIONS IonLiq-Polym-15
Invited Talk
Temperature Dependence of Intermolecular Vibrational
Dynamics in Room Temperature Ionic Liquids
Shohei Kakinuma, Hideaki Shirota
Department of Chemistry, Chiba University, 1-33 Yayoi, Inage-ku, Chiba 263-8522, Japan
Room temperature ionic liquids (ILs) are molten salts at room temperature. Many ILs include
organic cations having a relatively long hydrophobic alkyl group. This causes unique
properties, such as micro-segregation structure and low melting point. Because the
intermolecular vibrational dynamics (or low-frequency spectrum less than ca. 200 cm-1
) in
condensed phases is influenced by the microscopic structure and intermolecular interactions,
it is essential to study. Our group has reported the data of the intermolecular vibrational
dynamics of 40 ILs and revealed some general and overall features of the intermolecular
vibrational dynamics in aromatic cation based ILs.1 Currently, we are studying the
temperature dependence of the intermolecular vibrational dynamics in ILs by femtosecond
Raman-induced Kerr effect spectroscopy. So far, we have found that (i) the low-frequency
spectrum in imidazolium-based ILs is temperature dependent, (ii) the imidazolium ring
libration is strongly influenced by temperature,2 (iii) anion species influence the temperature
dependence of the low-frequency spectrum relatively small compared to the imidazolium
cation, and (iv) the temperature dependence of the first moment of low-frequency spectrum in
ILs is quite similar to that in neutral analogue 1-methylimidazole and is not correlated to the
fragility parameter.3 In this presentation, we will further discuss the effects of cation (not
only imidazolium but also pyridinium and nonaromatic cations) on the temperature dependent
low-frequency spectrum in ILs. The temperature dependence of the low-frequency spectra of
neutral analogues will also be compared. This work was supported by JSPS KAKENHI
(15K05377).
REFERENCES
1. Shirota, H., Kakinuma, S., Takahashi, K., Tago, A., Jeong, H., Fujisawa, T. Ultrafast Dynamics in Aromatic
Cation Based Ionic Liquids: A Femtosecond Raman-Induced Kerr Effect Spectroscopic Study. Bull. Chem. Soc. Jpn.
89, 1106-1128 (2016). 2. Shirota, H., Kakinuma, S., Temperature Dependence of Low-Frequency Spectra of Molten
Bis(trifluoromethylsulfonyl)amide of Imidazolium Cations Studied by Femtosecond Raman-Induced Kerr Effect
Spectroscopy. J. Phys. Chem. B 119, 9835–9846 (2015). 3. Kakinuma, S., Ishida, T., Shirota, H. Femtosecond Raman-Induced Kerr Effect Study of Temperature-Dependent
Intermolecular Dynamics in Imidazolium-Based Ionic Liquids: Effects of Anion Species and Cation Alkyl Groups. J.
Phys. Chem. B 121, 250-264 (2017).
IonLiq-Polym-16 ORAL CONTRIBUTIONS
Invited Talk
Dynamics and Local Structures of Mixtures of CS2 in
Monocationic and Dicationic Ionic Liquids: OHD-RIKES
Measurements and Molecular Dynamics Simulations
Eshan Gurunga, George Tamas
a, Ruth Lynden-Bell
b and Edward L. Quitevis
a
aDepartment of Chemistry & Biochemistry, Texas Tech University, Lubbock, Texas 79409,
USA; bDepartment of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
Because of nanostructural heterogeneity, the solvation properties of ionic liquids (ILs) can be quite
different than that of molecular liquids, with solute molecules tending to localize in the domains for
which they have the greatest affinity. Moreover, the dynamics of the solute will reflect its local
environment. In particular, because a nonpolar solute will tend to localize in the nonpolar domains, its
dynamics should reflect that of an alkane local environment, as recently shown in OHD-RIKES
studies of mixtures of CS2 and imidazolium-based ILs.1,2
These studies showed that the CS2
contribution to the Kerr spectra of a CS2/IL mixture resembles that of the Kerr spectra of a CS2/alkane
mixture. For CS2/IL mixtures, molecular dynamics (MD) simulations show CS2 localized in the
nonpolar domains.1
Here we report a comparative OHD-RIKES study of the intermolecular spectrum
of CS2 in monocationic ILs (MILs) [CNC1im][NTf2] and dicationic ILs (DILs) [(C1im)C2Nim][NTf2]2
for N = 3, 4, and 5. In this study, the mole fraction of CS2 in these mixtures is such that the ratio of
CS2 molecules to imidazolium rings is the same in a given MIL/DIL pair with the same N. We find
that the CS2 contribution to the Kerr spectra is higher in frequency for the CS2/DIL mixture than for
the CS2/MIL mixture, with both cases lower in frequency than the Kerr spectra of neat CS2. MD
simulations were performed on CS2/[C4C1im][NTf2] and CS2/[(C1im)C8im][NTf2]2 mixtures to
determine the local structure and dynamics of CS2 in these mixtures. As in a previous study,3 a
polarizable model was used for CS2 in these simulations. The simulations show that because the
number density of the IL (e.g., the imidazolium rings) is greater in the DIL than in the MIL, the CS2
density of states are higher in frequency in the DIL than in the MIL, which is consistent with the
observed trend in the Kerr spectra of these CS2/IL mixtures.
REFERENCES
1. Yang, P., Voth, G. A., Xiao, D., Hines, L. G. Jr., Bartsch, R. A., Quitevis, E. L., Nanostructural
organization in carbon disulfide/ionic liquid mixtures: molecular dynamics simulations and optical Kerr
effect spectroscopy, J. Chem. Phys. 135, 03402 (2011).
2. Xue, L., Tamas, Gurung, E. Quitevis, E. L., Probing the interplay between electrostatic and dispersion
interactions in the solvation of nonpolar aromatic molecules in ionic liquids: an OKE spectroscopic study of
CS2/[CnC1im][NTf2] mixtures (n = 1-4), J. Chem. Phys. 140, 16512 (2014).
3. Lynden-Bell, R. M., Quitevis, E. L., The importance of polarizability: comparison of models of carbon
disulphide in the ionic liquids [C1C1im][NTf2] and [C4C1im][NTf2], Phys. Chem. Chem. Phys. 18, 16535-
16543 (2016).
ORAL CONTRIBUTIONS IonLiq-Polym-17
Invited Talk
Influence of polymerization on charge dynamics of ionic
melts
F. Wieland,1 P. Münzner,
1 W. Hiller,
2 A. P. Sokolov,
3 R. Böhmer,
1 and C.
Gainaru1
1 Faculty of Physics, TU Dortmund University, D-44221 Dortmund, Germany
2 Faculty of Chemistry and Chemical Biology, TU Dortmund University, D-44221 Dortmund,
Germany
3Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, USA
Understanding the microscopic mechanisms governing the charge transport is the key for any
rational design of electrochemical materials with large energy storage and transport
capabilities. In this respect amorphous conductors such as ionic liquids (ILs) and polymer
electrolytes are well investigated. However, information on the strongly emerging class of
materials formed by polymerized ionic liquids (PolyILs) is sparse, largely due to the fact that
these compounds are not yet commercially available. In this work we analyze the variation of
charge dynamics in monomeric, oligomeric, and long-chain ionic melts by means of dielectric
spectroscopy, rheology, and field-gradient nuclear magnetic resonance. The length of the
positively charged backbone is systematically increased while the type of anions and their
concentration are kept invariant [1]. Surprisingly, indications of decoupling between the
dynamics of positive and negative charges occur already for oligomers comprising three
monomeric units only. Considering the striking difference between the mobilities of their
anions and cations, PolyILs are systems in which only one type of ions governs the
conductivity, in other words they are perfect testing grounds for phenomenological and
theoretical approaches. In this respect we demonstrate that the revised solution of Dyre’s
Random Barrier Model [2,3] is able to describe the salient features of both conductivity and
relaxation spectra in these materials. Additionally, we will discuss the non-linear conductivity
response in these materials and the applicability of a recently introduced approach able to
estimate the ion diffusivity from the conductivity relaxation spectra without any adjustable
parameters [4].
REFERENCES
1. Fan, F., Wang, W., Holt, A. P., Feng, H., Uhrig, D., Lu, X., Hong, T., Wang, Y., Kang, N.-G., Mays, J.,
and Sokolov, A. P., Macromolecules. 49, 4557–4570 (2016).
2. Dyre, J. C., Phys. Lett. 108A, 457461 (1985);
3. Schrøder, T. B. and Dyre, J. C., Phys. Rev. Lett. 101, 025901 (2008).
4. Gainaru, C., Stacy, E. W., Bocharova, V., Gobet, M., Holt, A. P., Saito, T., Greenbaum, S., and Sokolov, A.
P., Phys. Chem. B 120, 11074–11083 (2016).
IonLiq-Polym-18 ORAL CONTRIBUTIONS
Invited Talk
Ionic and Non-ionic Deep Eutectics: Polarity and Possible
Origin of Relaxation Timescales
Ranjit Biswas
S. N. Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake, Kolkata, West
Bengal, India
Deep eutectic solvents (DESs), by virtue of their exquisite solvent properties, economic
viability, easy preparation and transport protocol, are fast emerging as media for large scale
industrial and technological applications.1,2
DESs are composed of multi-component solids
where liquid phase is accessed at temperatures much lower than the melting temperatures of
individual components. A thorough study of structure and dynamics of these ‘metastable’
systems is required for smarter use of these multi-component melts as reaction media.3-10
For
this purpose, we have considered here two representative DESs: one that is non-ionic in
character and composed of acetamide and urea; the other one is ionic in nature and composed
of acetamide and electrolytes. Temperature dependent dielectric relaxation measurements in
the frequency window, 50GHz2.0 , have been carried out for both these types of DESs.
Multi-Debye relaxations with time constants ranging from nanoseconds to picoseconds have
been detected in this relatively narrow frequency window. Subsequently, Computer
simulations for orientational relaxations and H-bond fluctuations have been performed to
ascertain the molecular processes that may give rise to the observed multi-Debye relaxations
in these systems.11-13
Structural and dynamic heterogeneity aspect have also been studied via
simulations. Some of these results will be presented and discussed in this talk.
REFERENCES
1. Wagle, D. V.; Zhao, H.; Baker, G. A. Acc. Chem. Res., 47, 2299 (2014).
2. Zhang, Q.; De Oliveira Vigier, K.; Royer, S.; Jerome, F. Chem. Soc. Rev., 7108 (2012).
3. Das, A.; Das, S.; Biswas, R. J. Chem. Phys., 142, 184504 (2015).
4. Das, A.; Biswas, R. J. Phys. Chem. B, 119, 10102 (2015).
5. Das, S., Biswas, R.; Mukherjee B. J. Phys. Chem. B, 119, 11157 (2015).
6. Guchhait, B.; Das, S.; Daschakraborty, S.; Biswas, R. J. Chem. Phys., 141, 104514 (2014).
7. Tripathy, S. N.; Wojnarowska, Z.; Knapik, J.; Shirota, H.; Biswas, R.; Paluch, M. J. Chem. Phys., 142, 184504
(2015).
8. Biswas, R.; Das, A.; Shirota, H. J. Chem. Phys., 141, 134506 (2014).
9. Guchhait, B.; Gazi, H. A. R.; Kashyap, H. K.; Biswas, R. J. Phys. Chem. B, 114, 5066 (2010).
10. Guchhait, B.; Daschakraborty, S.; Biswas, R. J. Chem. Phys., 136, 174503 (2012).
11. Mukherjee, K.; Das, A.; Choudhury, S.; Barman, A.; Biswas, R. J. Phys. Chem. B, 119, 8063 (2015).
12. Das, S., Biswas, R.; Mukherjee B. J. Chem. Phys. B, 145, 084504 (2016).
13. Mukherjee, K.; Das, S.; Barman, A.; Biswas, R. J. Chem. Phys. (2017-submitted).
14. Das, S.; Mukherjee, B.; Biswas, R. J. Chem. Sci. (2017-in press).
15. Mukherjee, K.; Das, S.; Barman, A.; Biswas, R. Fluid Phase Equilibria (2017-in press).
ORAL CONTRIBUTIONS IonLiq-Polym-19
Invited Talk
Ion transport in polymerized ionic liquids: structure-
morphology-property relationships
Joshua Sangoro1, Maximilian Heres
1, Tyler Cosby
1, Hongjun Liu
1, Stephen
Paddison1, Ciprian Iacob
2, and James Runt
2
1Department of Chemical & Biomolecular Engineering, University of Tennessee, 1512 Middle
Drive, Knoxville, TN 37996-2200
2Department of Materials Science and Engineering, The Pennsylvania State University,
University Park, PA 16802 U.S.A
Polymerized ionic liquids (PolyILs) are a novel class of functional polymers that combine the
unique physicochemical properties of molecular ionic liquids with the outstanding mechanical
characteristics of polymers. This special mix of features might help to circumvent the key
limitations of low molecular weight ionic liquids, namely, leakage and poor mechanical properties
while utilizing their outstanding characteristics such as low vapor pressures, wide liquidus ranges,
high thermal stability, high ionic conductivity, and wide electrochemical windows. PolyILs have
shown remarkable advantages when employed in electrochemical devices such as dye-sensitized
solar cells, lithium batteries, actuators, field-effect transistors, light emitting electrochemical cells,
and electrochromic devices, among others. Despite their promising prospects as ideal polymer
electrolytes, the role of molecular structure, morphology, and polymer dynamics on charge
transport in PolyILs remains poorly understood. This talk will focus on new insights obtained
from experimental studies employing broadband dielectric spectroscopy, temperature-modulated
differential scanning calorimetry, rheology, and scattering techniques to elucidate the impact of
morphology on charge transport and structural dynamics in systematic series of polymerized
ammonium- and imidazolium- based ionic liquids. Detailed analyses reveal strong decoupling of
these processes in the PolyILs, implying the limitation of the classical theories in describing
charge transport and molecular dynamics in these materials, in contrast to low molecular weight
systems. In addition, the strong correlation observed between ionic conductivity from dielectric
experiments and morphologies from scattering and computational studies will be discussed.
REFERENCES
1. Sangoro, J. R. et al., Decoupling of ionic conductivity from structural dynamics in polymerized ionic
liquids. Soft Matter, 10 (20), 3536-3540 (2014)
2. Heres, M.; Cosby, T.; Mapesa, E. U.; Sangoro, J. Probing Nanoscale Ion Dynamics in Ultrathin Films of
Polymerized Ionic Liquids by Broadband Dielectric Spectroscopy. ACS Macro Lett., 5 (9), 1065–1069
(2016).
IonLiq-Polym-20 ORAL CONTRIBUTIONS
Invited Talk
Universal scaling laws for the ionic conductivity
A. Serghei1, M. Samet
2, G. Boiteux
1, A. Kallel
2
1Université Lyon1, Ingénierie des Matériaux Polymères, CNRS UMR 5223,
69622 Villeurbanne, France
2Faculté des Sciences de Sfax, Laboratoire des Matériaux Composites Céramiques et
Polymères, 3018 Sfax, Tunisia
The electrical and dielectric properties of ion-conductive materials can be characterized by
measuring, in a broad frequency and temperature range, the complex permittivity function or,
equivalently, the complex conductivity function of the samples under investigation. The
spectral dependence of these parameters is marked by several characteristic frequencies
reflecting different physical phenomena of charge transport and charge fluctuations which
take place in the volume of the material as well as at the interfaces with the measurement cell.
Here we show that ion-conductive materials show a universal behavior in terms of their
characteristic frequencies. Plotted as a function of the DC-conductivity for a variety of
different ion-conductive materials (pure ionic liquids, conductive polymers, polyionic liquids,
blends), these characteristic frequencies collapse onto a single line, which indicate an
universal behavior for the ionic conductivity. This universality has far-reaching consequences.
Knowing the DC-conductivity of a given ion-conducting material allows one to accurately
determine its characteristic frequencies and reconstruct by that, in a broad frequency range,
the whole spectral dependence of its electrical and dielectric properties.
The current contribution will furthermore present in detail a recently developed experimental
approach allowing one to characterize, based on the phenomenon of electrode polarization,
the diffusion process of ionic liquids into polymeric materials.
REFERENCES
1. “Dielectric Properties of Ionic Liquids at Metal Interfaces: Electrode Polarization, Characteristic
Frequencies, Scaling Laws”, by A. Serghei, M. Samet, G. Boiteux, A. Kallel in the book “Dielectric
Properties of Ionic Liquids” ed. Marian Paluch, Springer 2016.
ORAL CONTRIBUTIONS IonLiq-Polym-21
Invited Talk
Cooperative Dynamics of Protic Ionic Liquids and their
Mixtures with Polar Solvents
Andreas Nazet and Richard Buchner
Dept. of Chemistry, Universität Regensburg, 93040 Regensburg, Germany
Protic ionic liquids (PILs) are an emerging sub-class of ionic liquids with unique properties
due to the presence of proton-donor and acceptor sites on the cations and anions. Thus, in
addition to the Coulomb and van-der-Waals interactions dominating the properties of aprotic
ionic liquids, strong hydrogen bonds can be formed among the ions but also with suitable
solutes. For instance, such ionic liquids promote the aggregation of amphiphilic solutes and a
Grotthus-type proton-hopping mechanism was suggested to explain their extraordinary high
conductivities.1,2
Ammonium based ionic liquids like ethylammonium nitrate (EAN) are of particular interest
as they show many properties reminiscent of water and interesting phase behavior when
mixed with aprotic solvents3,4,5
In this contribution we compare cooperative dynamics –
probed by dielectric spectroscopy in the microwave region- and transport properties of
various alkylammonium ILs and discuss the influence of cation and anion structure. In the
second part of the presentation mixtures of EAN with various protic and aprotic polar
solvents, namely water, methanol, N,N-dimethylacetamide, dimethylsulfoxide, acetonitrile
and nitromethane are discussed. We show that in these mixtures PIL form a continuous H-
bond system with protic solvents whereas with aprotic solvents it depends on the
protophilicity of the solvent. Either fingerprints of heteroassocation via hydrogen-bonding are
found or segregation into PIL-rich and solvent-rich domains occurs, eventually leading to
phase separation.
REFERENCES
1. Wojnarowska, Z; Paluch, M., Recent progress on dielectric properties of protic ionic liquids, J. Phys.:
Condens. Matter 27, 073220 (2015).
2. Greaves, T. L.; Drummond, C. J., Protic ionic liquids: evolving structure−property relationships and
expanding applications, Chem. Rev. 115, 11379−11448 (2015).
3. Govinda, V.; Venkatesu, P; Bahadur, I., Molecular interactions between ammonium-based ionic liquids and
molecular solvents: current progress and challenges, Phys. Chem. Chem. Phys. 18, 8278-8326 (2016).
4. Sonnleitner, T.; Nikitina, V.; Nazet, A.; Buchner R., Do H-bonds explain strong ion aggregation in
ethylammonium nitrate + acetonitrile mixtures?, Phys. Chem. Chem. Phys. 15, 18445-18452 (2013).
5. Nazet, A.; Weiß, L.; Buchner, R., Dielectric relaxation of nitromethane and its mixtures with
ethylammonium nitrate: Evidence for strong ion association induced by hydrogen bonding, J. Mol. Liq. 228,
81-90 (2017).
IonLiq-Polym-22 ORAL CONTRIBUTIONS
Oral
Phonon-like hydrogen-bond modes in protic ionic liquids
Judith Reichenbach, Stuart A. Ruddell, Mario González -Jiménez, Julio
Lemes, David A. Turton, David J. France, and Klaas Wynne
School of Chemistry, WestCHEM, University of Glasgow, UK,
Gigahertz to terahertz frequency infrared and Raman spectra contain a wealth of information
concerning the structure, inter-molecular forces, and dynamics of ionic liquids. However,
these spectra generally have a large number of contributions ranging from slow diffusional
modes to underdamped librations, and intramolecular vibrational modes. This makes it
difficult to isolate effects such as the role of coulombic and hydrogen-bonding interactions.
We have applied far-infrared and ultrafast optical Kerr-effect spectroscopies1,2
on carefully
selected ions with a greater or lesser degree of symmetry in order to isolate spectral signals of
interest. This has allowed us to demonstrate the presence of LO and TO phonon modes and a
great similarity to liquid water of alkylammonium-based protic ionic liquids. The data show
that such phonon modes will be present in all ionic liquids requiring a reinterpretation of their
spectra.
REFERENCES
1. Turton, D. A. et al. Terahertz underdamped vibrational motion governs protein-ligand binding in solution.
Nat Commun 5, 3999 (2014).
2. González Jiménez, M. et al. Observation of coherent delocalized phonon-like modes in DNA under
physiological conditions. Nat Commun 7, 11799 (2016).
ORAL CONTRIBUTIONS IonLiq-Polym-23
Invited Talk
Charge transport mechanism ionic glass formers
Z. Wojnarowska1,2
, V. Bocharova2, A.Sokolov
2, M. Paluch
1
1University of Silesia in Katowice, Institute of Physics, Uniwersytecka 4, 40-007 Katowice
2Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831,
USA
Efficient generation and utilization of energy has become one of the greatest challenges of our
time. This in turn creates a growing demand for various types of energy storage devices in
household and industry. Therefore, a significant research effort during the past decade has
been focused on development of new functional materials for diverse energy storage
applications. The family of ionic liquids (ILs) and their polymerized counterparts offers an
ideal solution for these purposes. However, the rational design of ILs and polyILs requires
fundamental understanding of the microscopic parameters controlling their macroscopic
properties, including conductivity. For this reason, in recent years much effort has been
dedicated to fundamental understanding of the charge transport mechanism in these systems.
In this talk we present the conducting properties of several low and macromolecular ionic
glass-formers. To reveal the charge transport mechanism in these materials we employ
ambient and high pressure dielectric measurements. We show that isothermal compression
offers a unique possibility to recognize the dominating charge transport mechanisms as well
as to control the conducting properties of ionic systems, both being crucial in their potential
electrochemical applications. We demonstrate that the proton transfer mechanism can be
easily distinguished from vehicle conduction even without knowing the chemical structure of
the studied system.
ACKNOWLEDGEMENT
Authors are deeply grateful for the financial support by the National Science Centre within
the framework of the Opus 8 project (Grant No. DEC-2014/15/B/ST3/04246). This work was
supported by Laboratory Directed Research and Development program of Oak Ridge
National Laboratory, managed by UT-Battelle, LLC, for the U.S. Department of Energy.
REFERENCES
1. Wojnarowska, Z., Paluch, M. J. Phys.: Condens. Matter 27, 073202, (2015).
2. Paluch, M. Dielectric properties of ionic liquids, Springer: Berlin (2016).
IonLiq-Polym-24 ORAL CONTRIBUTIONS
Oral
Microscopic ionic dynamics of Ca0.4K0.6(NO3)1.4 and its
relation to fragility
Makina Saito1, Yohei Onodera
1, Ryo Masuda
1, Yoshitaka Yoda
2, Koji
Ohara2, and Makoto Seto
1
1Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka, Japan
2Research and Utilization Division, Japan Synchrotron Radiation Research Institute, Kouto,
Sayo-cho, Sayo-gun, Hyogo, Japan
Understanding the origin of “fragility” is one of the central issues of the glass
transition phenomena, and observation of the whole microscopic dynamics is a key to solve it.
Owing to the structural simplicity of its constituents, Ca0.4K0.6(NO3)1.4 (CKN) is a model
system of the glass formers with a large fragility index m and has been much studied e.g., for
the test of the mode coupling theory. In order to reveal the microscopic origin of a large
fragility index of CKN, detailed ionic dynamics of supercooled and glassy CKN was studied
by using newly developed quasi-elastic scattering method using gamma-rays based on the
glassy structure derived from reverse Monte Carlo modeling with X-ray diffraction data.
Firstly, we performed X-ray diffraction experiment on CKN in BL04B2 of SPring-8
and reverse Monte Carlo modeling based on the X-ray diffraction data was carried out to
obtain the three-dimensional structure of CKN glass. Then, partial structure factors were
obtained for the all atomic pairs from the modeled structure. Next, based on the structural
information, we studied slow microscopic dynamics of the ions in supercooled and glassy
CKN at several temperatures by using quasi-elastic scattering method using gamma-rays
time-domain interferometry in BL09XU of SPring-8.1,2
We found that the momentum transfer
dependence of the relaxation time shows the maximum only at around the peaks of the K-O
and Ca-O partial structure factors. This finding suggests that the K-O and Ca-O pairs show
relatively longer life time comparing with the other pairs owing to relatively strong ionic
interaction. In presentation, further detailed static and dynamic picture of CKN is described.
Moreover, we discuss the microscopic origin of fragility based on the observed relation
between microscopic dynamics and fragility index on CKN and other several glass formers.
REFERENCES
1. Baron, A. Q. R. et. al. Quasielastic scattering of synchrotron radiation by time domain interferometry.
Phys. Rev. Lett. 79, 2823–2826 (1997).
2. Saito, M. et. al. Slow processes in supercooled o-terphenyl: relaxation and decoupling. Phys. Rev. Lett. 109,
115705 (2012).
ORAL CONTRIBUTIONS IonLiq-Polym-25
Invited Talk
Correlated Movements of Cations and Anions
in Ionic Liquid-based Electrolytes
Fabian Wohde, Marco Balabajew, Bernhard Roling
Department of Chemistry, University of Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg,
Germany
Liquid electrolytes based on carbonates, glymes and ionic liquids (IL) are used for various
applications in electrochemistry, e.g. for electrodeposition, for corrosion inhibition, for
supercapacitors, for dye-sensitized solar cells and for lithium-ion batteries. In the case of
lithium-ion batteries, the transport properties of Li+ ions under the influence of electric
potential gradients and concentration gradients play an important role for the battery
performance. In order to assess these transport properties, transport numbers and transference
numbers of Li+ ions have been measured by means of various experimental techniques, such
as pulsed field gradient NMR (PFG-NMR) and potentiostatic polarization techniques [1]. For
ideal electrolytes, transference and transport numbers are identical. However, this is not the
case for concentrated battery electrolytes. Consequently, ion transport limitations in batteries
cannot be predicted exclusively from transport numbers obtained by PFG-NMR.
We have measured the Li+ transference numbers of different concentrated electrolytes by
means of very-low-frequency impedance spectroscopy (VLF-IS) [2]. Our results reveal hugh
differences between electrochemical Li+ transference numbers and PFG-NMR-based Li
+
transport numbers. In order to rationalize these differences, we combine the Onsager
reciprocal relations with linear response theory, and we derive expressions for the
electrochemical Li+ transference number, which take into account all correlations between
ionic movements in the electrolyte. Thereby, we show that in particular strong cation-anion
correlations can lead to low values of the electrochemical Li+ transference number and, in
turn, to considerable ion transport limitations in batteries. We disucss the implications of
these finding for the Haven ration of ionic liquids.
REFERENCES
1. Zugmann, S., Fleischmann, M., Amereller, M., Gschwind, R.M., Wiemhöfer, H.D., Gores, H.J.,
Electrochim. Acta 56, 3926–3933 (2011).
2. Wohde, F., Balabajew, M., Roling, B., J. Electrochem. Soc. 163, A714-A721 (2016).
IonLiq-Polym-26 ORAL CONTRIBUTIONS
Invited Talk
New Method for the Estimation of Transport Properties of
Electrolytes containing Ionic Liquids using Modified
UNIFAC-Based Models
Nan Zhao1, Ryan Oozeerally
2, Volkan Degirmenci
2, Zdeněk Wagner
3,
Magdalena Bendová3, Johan Jacquemin
1,4
1 School of Chemistry and Chemical Engineering, Queen’s University Belfast, Belfast BT9 5AG, UK.
2 School of Engineering, University of Warwick, Coventry CV4 7AL, UK
3 E. Hála Laboratory of Thermodynamics, Institute of Chemical Process Fundamentals AS CR, v. v. i.
Rozvojová 135, 165 02 Prague 6 – Suchdol, Czech Republic
4 Université François Rabelais, Laboratoire PCM2E, Parc de Grandmont 37200 Tours, France
[email protected]; [email protected]
Modified UNIFAC-VISCO [1-2] and UNIFAC-CONDUCTIVITY [3] group contribution
methods were developed for the correlation and estimation of the transport properties of a
series of pure ILs and their mixtures with molecular solvents as a function of temperature and
composition at 0.1 MPa using a large set of recommended data from the literature. During this
work, experimental data were critically assessed using the statistical method and
mathematical gnostics to highlight recommended data used then to develop the modified
UNIFAC-based models.[2] In this original approach, exemplified in Figure 1 in the case of
the viscosity of pure ionic liquids, the salt (ionic liquids and/or molten salts) was divided into
two peculiar function groups, cation and anion. Binary interaction parameters were
determined by fitting the recommended experimental data and by minimizing the objective
function. The transport properties of cations, anions, and salts showed an exponential
behavior with the temperature well described thanks to the Vogel-Fulcher-Tamman (VFT)
equation. Calculated VFT constants and binary interaction parameters were used to evaluate
the viscosity, conductivity, diffusion coefficients and ionicity of selected electrolytes.
The estimation result showed a good agreement with experimental data with a relative
absolute average deviation lower than 5 % in each case.[1-3] This novel approach will be
presented and discussed in detail during this presentation.
REFERENCES
1. Zhao, N.; Jacquemin, J.; Oozeerally, R.; Degirmenci, V. J. Chem. Eng. Data 61, 2160-2169 (2016).
2. Zhao, N.; Oozeerally, R.; Degirmenci, V.; Wagner, Z.; Bendová, M; Jacquemin, J. J. Chem. Eng. Data 61,
3908-3921 (2017).
3. Zhao, N.; Jacquemin, J. submitted to Fluid Phase Equilibria on the 23rd February 2017.
ORAL CONTRIBUTIONS IonLiq-Polym-27
Oral
Nucleation and phase growth of ionic liquid crystal
(C8mim) BF4
Keisuke Watanabe, Tsukasa Katsumata, Tomomi Komai, Keishi Negita
Department of Chemistry, Faculty of Science, Fukuoka University, Nanakuma 8-19-1,
Jonan-ku, Fukuoka, 814-0180
Ionic liquid has singular physicochemical properties. This material is considered to have some
mesoscopic order in the liquid state, which depends on the combination of ions constituting the
ionic liquid. Recent thermal studies by DSC have investigated the phase behavior of imidazolium-
based ionic liquids depending on alkyl chain length of the cations. In principle, it is known that its
longer alkyl chain tends to induce the occurrence of the liquid crystal phase.
Holbrey et al. have studied the phase behavior of 1-alkyl-3-methylimidazolium
tetrafluoroborate (Cnmim) BF4, n represents the number of carbon-chain length of the cations. [1].
They found that when n is larger than 9, (Cnmim) BF4 undergoes a phase transition to the smectic
phase with its normal scanning rate of typical DSC. However, we have found the very slow
cooling or long-time annealing induces the smectic phase in the ionic liquid, 1-methyl-3-
octylimidazolium tetrafluoroborate (C8mim) BF4 [2]. It takes more than 90 hours till the
completion of the phase transition from liquid to smectic phase. Such very slow phase growth
could not be detected by DSC with its normal scanning rate.
Interestingly, the smectic phase by X-ray diffraction can be observed only when the
sample is cooled just below Tg, that is the glass transition temperature 193 K, annealed at Tg
isothermally for 12 hours, and then heated to 223 K, which is at 13 K below the melting point 246
K. In contrast, without the cooling and annealing at around Tg, the smectic phase in (C8mim) BF4
cannot be observed during 12-hour isothermal-annealing at 223 K just after cooling from room
temperature. Thus, we concluded that the nucleation rate of the smectic phase in (C8mim) BF4
considerably increases at around Tg, but it is negligible frequency above Tg. However, it is noticed
that the slower cooling from room temperature or long-time annealing at 223 K before nucleation
around Tg obviously increase the phase-growth rate after the nucleation. This implies that without
nucleation this ionic liquid slowly varies the mesoscopic order in the supercooled liquid state
above Tg to accelerate the phase growth of its smectic phase.
REFERENCES
1. Holbrey, J.D., Seddon, K.R., J. Chem. Soc. Dalton Trans. 13, 2133-2139 (1999).
2. Watanabe, K., Nimonji, A., Negita, K., 33rd International Conference on Solution Chemistry (2013).
IonLiq-Polym-28 ORAL CONTRIBUTIONS
Invited Talk
The Gating of YBCO EDLT with an ionic liquid probed by
Dielectric Spectroscopy
A. Rivera-Calzada, A. Pérez-Muñoz, J. García-Barriocanal,
C. León, and J. Santamaría
GFMC, Facultad de Física, Universidad Complutense Madrid, 28040 Madrid, Spain
Electric Double Layer Transistors (EDLT) are becoming popular devices for inducing novel
phases in correlated materials. In this configuration the gating is applied at a separate
electrode and translated via an ionic liquid to the surface of the material under study,
producing carrier densities up to 5*1014
cm-2
, 50 times larger than the limit of MOSFET
devices with solid SiO2 [1,2].
In this work we present a characterization of the ionic liquid mostly used in these
experiments, the N,N-diethyl-N-(2-methoxyethyl)-N-methylammonium bis-(trifluoromethyl
sulfonyl) imide (DEME-TFSI) by means of dielectric spectroscopy. Both the bulk behavior
and “in operando“ response are probed. An EDLT formed by a thin film of the high-Tc
YBa2Cu3O7-x (YBCO) and the DEME TFSI ionic liquid shows the different regimes
corresponding to the bulk ionic liquid behavior, the charge accumulation, and traces of
electrochemical reactions at the YBCO surface, at the different gating voltages.
REFERENCES
1. Yuan, et al. Electrostatic and electrochemical nature of liquid-gated electric-double-layer transistors based
on oxide semiconductors, JACS. 132, 18402 (2010)
2. Fujimoto, T. and Awaga, K. Electric-double-layer field-effect transistors with ionic liquids. PCCP. 15, 8983
(2013)
3. Perez-Muñoz , A. M., et al. In operando evidence of deoxygenation in ionic liquid gating of
YBa2Cu3O7-X, PNAS 114, 215 (2017)
ORAL CONTRIBUTIONS Ion-Por-Nano-1
Invited Talk
Nanoionics based on oxide interfaces
O.J. Dura*, M. A. Frechero§, D. Hernandez -Martin, J. Tornos, G. Sanchez-
Santolino, A. Rivera, M. Varela, J. Santamaria and C. Leon
GFMC, Departamento de Física de Materiales, Facultad de Fisica, Universidad Complutense
de Madrid, 28040 Madrid, Spain
The control of ionic transport in oxides at the nanoscale may be key to develop nanoionic
devices with improved or new functionalities such as multi-bit memories and logic elements
based on memristors, or on tunnel junctions with ionically conducting barriers. In thin film
oxide heterostructures, manipulating the concentration of mobile oxygen vacancies within a
thickness of just a few unit cells is possible by using ion blocking interfaces and appropriate
electric fields, but it requires more knowledge about ion transport at the nanoscale. In
particular, it is important to understand the microscopic origin of the barrier for ion transport
at interfaces, which is not well established yet. By using a single grain boundary in a bicrystal
of the oxide ion conductor 9 mol % yttria stabilized zirconia (YSZ), we have recently
proposed that the conventional description in terms of a Mott-Schottky model fails in oxides
with a large concentration of mobile ions, and no space charge regions develop at the
interface [1]. We show here further evidences confirming our result by combining STEM-
EELS aberration corrected microscopy, and broadband dielectric spectroscopy measurements.
We present also some recent results on how novel functionalities can be achieved in
nanoionic devices by using ion transport at the nanoscale [2].
* on leave from Universidad de Castilla la Mancha, Ciudad Real, Spain
§ on leave from Universidad Nacional del Sur, Bahía Blanca, Argentina
REFERENCES
1. Frechero M. A. et al., Paving the way to nanoionics: atomic origin of barriers for ionic transport through
interfaces, Scientific Reports. 5, 17229 (2015).
2. Sanchez-Santolino, G. et al., Resonant electron tunnelling assisted by charged domain walls in multiferroic
tunnel junctions, Nature Nanotechnology (2017). doi:10.1038/nnano.2017.51
Ion-Por-Nano-2 ORAL CONTRIBUTIONS
Invited Talk
Molecular Dynamics of Ionic Transport in Nano-Porous
Systems –Enhanced Dynamics in Lithium Silicates
Junko Habasaki
School of Materials and Chemical Technology, Tokyo Institute of Technology, Nagatsuta
4259, Yokohama 226-8502, Japan
Ionic dynamics in porous materials are a new research front both in applications and
fundamentals. In some nano-porous materials, enhancement of ionic conductivity has been
reported [1]. Mechanism of it is not clarified yet, although several different explanations have
been proposed. To examine it, ionic motion in porous lithium disilicates was characterized by
Molecular Dynamics (MD) simulations [2]. In these simulations, pores are introduced by the
expansion of the systems in the NVE condition and details of structures and dynamics of ions
in nano-porous systems were examined. Remarkable enhancement of the diffusive motion of
Li ions is predicted and the maximum of the diffusion coefficient is found in the medium
density (and hence medium porosity) region as similar manner as in other porous systems
including several composites. Changes in the mean squared displacement (MSD) and
temperature dependence of them are useful to characterize the mechanism of the
enhancement. In the system with enhanced dynamics, MSD of ions shows a shortening of the
nearly constant loss (NCL) region, which means a loosening of the cage. When larger voids
are formed with a further decrease of density, tight cages are reformed and then the diffusion
coefficient decreases again. Thus these changes mainly originate from geometrical changes of
LiOx structures. Further modification of dynamics is brought by the changes in the slope of
the MSD in the power law region.
REFERENCES
1. Habasaki, J, León, C., Ngai, K.L., “Dynamics of Glassy, Crystalline and Liquid Ionic Conductors:
Experiments, Theories, Simulations”, Springer International, (2016), and references therein.
2. Habasaki, J., Molecular dynamics study of nano-porous materials—Enhancement of mobility of Li ions in
lithium disilicate, J. Chem. Phys., 145, 204503 (2016).
ORAL CONTRIBUTIONS Ion-Por-Nano-3
Invited Talk
Ionic Conductivity of Plastic Crystals
Daniel Reuter , Korbinian Geirhos, Carina Geiß, Peter Lunkenheimer and
Alois Loidl
Experimental Physics V, University of Augsburg, Germany
Molecular plastic crystals (PCs) exhibit technically relevant ionic conductivity when ions are
introduced in the system [1]. The molecules in a PC are ordered on a regular crystalline
lattice, however, they are able to freely reorient around their centers of mass. The high ionic
mobility found in some of these systems is often explained considering the reorientational
motion of the molecules located on the lattice sites. However, the understanding of this
mechanism is still incomplete. Steps towards a deeper understanding are crucial for the design
of advanced PC electrolytes for application in electrochemical devices.
By means of dielectric spectroscopy we have studied various mixture systems of PCs and we
interestingly found fundamentally different physical behavior in different mixture systems.
On this basis, we are able to identify two important mechanisms defining the ionic mobility in
PCs: the coupling of ionic translational diffusion to molecular reorientational motion [2] and
the timescale of the molecular reorientational dynamics [3].
REFERENCES
1. Alarco, P.-J., Abu-lebdeh, Y., Abouimrane, A., Armand, M., The plastic-crystalline phase of succinonitrile
as a universal matrix for solid-state ionic conductors, Nat. Mater. 3, 476-481 (2004).
2. Geirhos, K., lunkenheimer, P., michl, M., Reuter, D., Loidl, A., Conductivity enhancement in plastic-
crystalline solid-state electrolytes, J. Chem. Phys. 143, 081101 (2015).
3. Reuter, D., Geiss, C., Lunkenheimer, P., Loidl, A., Variation of ionic conductivity in a plastic-crystalline
mixture, arXiv:1704.07802.
Ion-Por-Nano-4 ORAL CONTRIBUTIONS
Invited Talk
7Li NMR studies on ion-conducting glass ceramics: from
local ionic jumps to long range transport
Michael Haaks*, Steve W. Martin
†, Michael Vogel
*
*Institut für Festkörperphysik, TU Darmstadt, Germany
†Department of Material Science and Engineering, Iowa State University, Ames, Iowa, USA
Rising energy demands call for improved performances of lithium ion batteries. In this
context, it is important to understand the dynamics of lithium ions, in particular, in
heterogeneous materials, which are used in modern strategies for material optimization.
Combining 7Li NMR spin-lattice relaxation, line-shape, and stimulated-echo analyses with
field-gradient diffusometry it is possible to investigate lithium ionic motions in wide range of
time and length scales. We exploit there capabilities to ascertain ion dynamics in 0.5Li2S-
0.5(xGeS2-(1-x)GeO2) [1] and 70Li2S-30P2S5 glasses, in particular, the effect of ceramization
for the latter electrolyte. We show that 7Li field-cycling relaxometry and two-phase spectra
enable straightforward determination of the distribution of energy barriers for the lithium
ionic jumps. For both classes of materials, we find broad Gaussian distributions, resulting in
enormous dynamical heterogeneity. Comparing the results with the ion diffusivities from 7Li
field-gradient approaches, we analyze the role of the strong heterogeneity of the local jumps
for the long range charge transport. In addition, our results for 70Li2S-30P2S5 allow us to
relate the enhancement of electronic conductivity under ceramization [2] to faster lithium ion
dynamics on various length scales.
REFERENCES
1. Gabriel, J., Petrov, O.V., Kim, Y., Martin, S.W., Vogel, M., lithium ion dynamicsins Li2S+GeS2+GeO2
glasses studied using 7Li NMR field-cycling relaxometry and line-shape analysis, Solid State nuclear
Magnetic Resonance 70, 53-62 (2015).
2. Mizuno, F. Hayashi, A., Tadanaga, K., tatsumisago, M., New, Highly Ion-Conductive Crystals Precipitated
from Li2S-P2S5 Glasses, Advanced Materials 17, No.7, 918-921 (2005)
ORAL CONTRIBUTIONS Met-Glas-1
Invited Talk
Structural Ordering and Dynamics in Metallic Glass-
Forming Liquids
K. F. Kelton, R. Ashcraft R. Dai, A. K. Gangopadhyay, C. E. Pueblo
Department of Physics and Institute of Materials Science and Engineering, Washington
University, St. Louis, Missouri 63130 USA
How structural changes in liquids correlate with changes in the dynamnical properties, and what
role these processes play in glass formation and the glass transition remain outstanding questions.
Although it is widely (but not universally) believed that the dynamical behavior is linked to the
atomic structure of the liquid, this has been difficult to demonstrate experimentally. While the
viscosity of the liquid changes by orders of magnitude with temperature, changes in the structure
static structure factor, S(q), or pair correlation function, g(r), are almost negligible. However, the
recent development of containerless processing methods and the introduction of intense X-ray and
neutron sources have now enabled these changes to be accurately measured in deeply supercooled
liquids.
This talk will focus on our recent results that confirm a correlation between dynamics and
structure in metallic glass-forming liquids and suggest a microscopic origin of a commonly used
metric to describe liquids, i.e. their fragility. A structural fragility parameter is introduced to
correlate kinetic fragility with the rate of structural ordering in the liquid [1]. Molecular dynamics
[2] and experimental studies [3] of the viscosity have identified a crossover temperature, TA, near
the liquidus temperature that marks the onset of cooperative behavior in shear flow. Our
structural data show that this correlates with the appearance of ordering in the liquid beyond
nearest neighbors, in agreement with recent MD calculations [4]. Fragility and the reduced glass
transition temperature, Trg, are known to correlate with glass formability, making them of
practical importance. As will be shown, both quantities can be predicted from liquid viscosity
measurements made near TA. This has led to a new method for predicting glass formation using
only data for the high temperature liquid. Finally, we demonstrate that in metallic liquids
fragility is related to the character of the atomic potential, with stronger liquids having a steeper
repulsive potential [5] and less anharmonicity.
REFERENCES
1. Mauro, N. A., Blodgett, M. E., Johnson, M. L., Vogt, A. J., Kelton, K. F., Nature Comm., 5 4616 (2014).
2. Iwashita, T., Nicholson, D. M., Egami, T., Phys. Rev. Lett. 110, (2013) 205504.
3. Blodgett, M., Egami, T., Nussinov, Z., Kelton, K. F., Sci. Reports, 5, (2015) 13837.
4. Soklaski, R., Tran, V., Nussinov, Z., Kelton, K. F., Yang, L., Phil. Mag., 96, 1212 (2016).
5. Pueblo, C. E., Sun, M., Kelton, K. F., arXiv:1701.08454.
Met-Glas-2 ORAL CONTRIBUTIONS
Invited Talk
Nature of Potential Energy Landscape
Takeshi Egami1 and Yue Fan
2
1Shull Wollan CenterJoint Institute for Neutron Sciences,
University of Tennessee and Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
2University of Michigan, Ann Arbor, MI 48103 USA
The nature of the potential energy landscape (PEL) of liquid and glass has been studied by
various methods, and we now have a good understanding of the distribution of the PEL
minima. However, less is known about the saddle points between the minima. By using the
activation-relaxation technique (ART) we explored the properties of the excitation process up
to the saddle point and relaxation down from the saddle point for a model binary metallic
glass [1]. We found that the energy barrier height for excitation, EA, depends strongly on the
cooling rate, thus the energy of the inherent structure, EIS, whereas the energy of relaxation
from the saddle point, ER, does not. This means that the processes of excitation and relaxation
are decoupled, and the system loses memory at the saddle point. The saddle point is a
common destination for many states, and is a vertex point with dense lines: The PEL is not
only highly multi-dimensional, but is extremely highly connected. Thus the conventional
picture (usually hand-written) of one-dimensional PEL is utterly misleading. The universal
equation derived with this assumption describes the evolution of the thermodynamic state
quite well [1]. It reproduced the results of molecular dynamics simulation of thermal cycles,
including the equilibrium line in the EIS vs temperature diagram which separates the domains
of relaxation and rejuvenation. We discuss the similarity of the nature of the saddle point and
that of liquid in terms of the negative curvature of local potential energy, and implications to
various properties, such as the glass transition, mechanical deformation, shear-transformation-
zone, and the Kauzmann paradox. This work was supported by the US Department of Energy,
Office of Science, Basic Energy Sciences, Materials Science and Engineering Division.
REFERENCE
1. Yue Fan, T. Iwashita, and T. Egami, Energy Landscape-Driven Nonequilibrium Evolution of Inherent
Structure in Disordered Material, Nature Communications, 8, 15417 (2017).
ORAL CONTRIBUTIONS Met-Glas-3
Oral
Density Scaling of Glassy Dynamics and Dynamic
Heterogeneities in Metallic Glass-forming Liquids
Yuan-Chao Hu and Wei-Hua Wang
Institute of Physics, Chinese Academy of Sciences, Beijing 100190 China
The discovery of density scaling in strongly correlating systems is an important progress for
understanding the dynamic behaviors of supercooled liquids. However, we found for a ternary
metallic glass-forming liquid, it is not strongly correlating thermodynamically, but its average
dynamics, dynamic heterogeneities and static structure are still well described by density
scaling with the same scaling exponent γ [1,2]. This may indicate the metallic liquid could be
treated as a single-parameter liquid. As an intrinsic material constant stemming from the
fundamental interatomic interactions, γ is theoretically predicted from the thermodynamic
fluctuations of potential energy and the virial. Although γ is conventionally understood
merely from the repulsive part of the inter-particle potentials, the strong correlation between γ
and the Grüneisen parameter up to the accuracy of the Dulong-Petit approximation
demonstrates the important roles of anharmonicity and attractive force of the interatomic
potential in governing glass transition of metallic glass-formers [1]. The supercooled
dynamics and density scaling behaviors will also be discussed in model glass-forming liquids
with tunable attractive potentials to further quantify the nonperturbative roles of attractive
interactions [3].
REFERENCES
1. Hu, Y. C., Shang, B. S., Guan, P. F., Yang, Y., Bai, H. Y., Wang, W. H., Thermodynamic scaling of glassy
dynamics and dynamic heterogeneities in metallic glass-forming liquid, The Journal of Chemical Physics
145, 104503 (2016);
2. Hu, Y. C., Guan, P. F., Wang, Q., Yang, Y., Bai, H. Y., Wang, W. H., Pressure effects on structure and
dynamics of metallic glass-forming liquid, The Journal of Chemical Physics 146, 024507 (2017);
3. Hu, Y. C., Su, R., Guan, P. F., Bai, H. Y., Wang, W. H., Unpublished.
Met-Glas-4 ORAL CONTRIBUTIONS
Invited Talk
Understanding the low-temperature relaxation in metallic
glasses by computational simulations
Pengfei Guan
Beijing Computational Science Research Center, China
Being a key feature of a glassy state, low temperature relaxation has important implications
on the mechanical behavior of glasses; however, the mechanism of low temperature relaxation
is still an open issue, which has been debated for decades. By systematically investigating the
influences of cooling rate and pressure on low temperature relaxation in the Zr50Cu50 metallic
glasses, it is found that even though pressure does induce pronounced local structural change,
the low temperature-relaxation behavior of the metallic glass is affected mainly by cooling
rate, not by pressure. According to the atomic displacement and connection mode analysis, we
further demonstrate that the low temperature relaxation is dominated by the dispersion degree
of fast dynamic atoms rather than the most probable atomic non-affine displacement.
Furthermore, we also investigated the maximum dynamical heterogeneity during the
unfreezing process in metallic glass and gave some information about the correlation between
low-temperature relaxation and alpha-relaxation. Finally, we will present some interesting
data about the beta-relaxation peak based on the computational simulations and the
correlation with the potential energy landscapes. Our finding may help us to understand the
atomic-level mechanisms of the low temperature-relaxation behaviors in metallic glasses.
REFERENCES
1. Wang, B., Shang, B. S., Gao, X. Q., Wang, W. H., Bai, H.Y., Pan, M.X., Guan, P.F., Understanding
Atomic-Scale Features of Low Temperature-Relaxation Dynamics in Metallic Glasses. J. Phys. Chem. Lett.
7 (23), 4945 (2016)
2. Wang, B., Wang, L. J., Wang, W. H., Bai, H. Y., Gao, X. Q., Pan, M. X., Guan, P. F., Understanding the
maximum dynamical heterogeneity during the unfreezing process in metallic glasses. J. Appl. Phys. (121)
175106 (2016)
3. Wang, B., Guan, P. F., unsubmitted
ORAL CONTRIBUTIONS Met-Glas-5
Invited Talk
Liquid-liquid transitions in metallic melts
Ralf Busch
Chair of Metallic Materials, Saarland University, Campus C6.3, 66123 Saarbruecken,
Germany
Polymorphic transitions are very common in crystalline metals and can be first order
transitions like e.g. from austenite to ferrite or second order like in the case of the ordering
transition from BCC to B2. Recently polymorphic transitions within the liquid state termed
polyamorphisms or liquid-liquid transitions (LLT) have been observed or proposed. This
contribution focuses on LLT in bulk metallic glass (BMG) forming melts and gives an
overview of recent developments.
The LLT in metallic melts is associated with a crossover from a relatively fragile kinetic
behavior at high temperatures to a stronger behavior at low temperatures [1-3]. If the
transition is not obscured by crystallization, one observes a latent heat of about 10% of the
heat of fusion associated with the LLT [3-4]. Recent synchrotron X-ray investigations show
that the kinetic fragility is linked to structural changes. [5]. In-situ electrostatic levitation
(ESL) undercooling experiments under synchrotron X-ray radiation reveal in the
Zr58.5Cu15.6Ni12.8Al10.3Nb2.8 (Vit106a) alloy system that the transition is associated with
structural changes on a length scale of about 1 nm indicating the establishment of medium
range order upon transformation [4].
The magnitude of entropy change in conjunction with the ordering energy determines the
critical temperature for the transition, which in most BMG forming liquids is located between
Tm and Tg. For some systems like Au-based BMG with a weak ordering energy, the LLT may
be hidden under the glass transition. In those systems the LLT can be revealed, if the alloy is
observed on a long time scale shifting Tg to lower temperatures. The picture emerges, that in
multicomponent BMG a LLT is rather the norm than an exception. In these systems the
fragility parameter changes from about D*=8-12 in the fragile high temperature liquid to
about D*=20-25 in the strong low temperature liquid.
REFERENCES
1. C. Way, P. Wadhwa, and R. Busch, Acta Materialia 55 (2007) 2977.
2. Z. Evenson, et al., Acta Materialia 60 (2012) 4712.
3. S. Wei et al. Nat Comm. 4 (2013) 2083.
4. M. Stolpe et al., Phys. Rev. B93, (2016) 014201.
5. S. Wei et al., Appl. Phys. Lett. 106 (2015) 181901.
Met-Glas-6 ORAL CONTRIBUTIONS
Invited Talk
Multiple aging regimes and anomalous dynamics in metallic
glasses
Beatrice Ruta1,2
1Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622
Villeurbanne Cedex, France
2ESRF-The European Synchrotron, CS40220, 38043 Grenoble, France
In recent years, the x-ray photon correlation spectroscopy technique has provided an
unprecedented look into the relaxation dynamics of hard and soft glasses by probing the
density fluctuations at the particle level. Studies on metallic glass formers have revealed the
existence of a dynamical crossover at the glass transition temperature, Tg, between an
equilibrium-like liquid state characterized by stretched exponential decays of the intermediate
scattering function (ISF), to a highly unstable glassy state with compressed ISF and multiple
aging regimes1-4
. Depending on the nature and the previous thermal history of the system, the
microscopic structural relaxation time is found to depend exponentially on the annealing
time1,2
or to jump through intermittent aging regimes3. This behavior appears connected to
ordering processes involving density changes at the medium range4 and displays many
similarities with the microscopic collective motion of concentrated colloidal suspensions and
gels. Furthermore, the spontaneous temporal equilibration toward the corresponding
supercooled liquid results strongly impeded by up temperature jumps from the glassy state, in
marked contrast macroscopic measurements. All these futures suggest a complex microscopic
picture of metallic glasses, not reflected in measurements of macroscopic quantities and in
theoretical studies.
REFERENCES
1. Ruta, B. et al. Atomic-Scale Relaxation Dynamics and Aging in a Metallic Glass Probed by X-Ray Photon
Correlation Spectroscopy, Phys. Rev. Lett. 109, 165701 (2012)
2. Ruta B. et al. Compressed correlation functions and fast aging dynamics in metallic glasses, J. Chem. Phys.
138, 054508 (2013)
3. Evenson Z. et al. X-Ray Photon Correlation Spectroscopy Reveals Intermittent Aging Dynamics in a
Metallic Glass, Phys. Rev. Lett. 115, 175701 (2015)
4. Giordano, V.M. & Ruta, B. Unveiling the structural arrangements responsible for the atomic dynamics in
metallic glasses during physical aging, Nat. Commun. 7:10344 (2016)
ORAL CONTRIBUTIONS Met-Glas-7
Invited Talk
Liquid-Liquid Transitions and their Underlying Structural
Changes: from Bulk Metallic Glassformers to Phase-
Change Materials
Shuai Wei
Arizona State University, School of Molecular Sciences, Tempe, 85296, AZ, USA.
Present address: RWTH Aachen University, I. Institute of Physics. 52074, Aachen, Germany
For bulk metallic glassforming liquids, we introduce an empirical quantitative structure-fragility
correlation1, which has been successfully validated in various Pt-, Au-, Zr-based bulk metallic glassforming
systems. Based on this correlation, a fragile-strong transition can be derived from structural data of liquid
Zr58.5Cu15.6Ni12.8Al10.3Nb2.8 (Vit.106a), where a liquid-liquid transition (LLT) in the deeply undercooled
state at T/Tg ∼1.2 was observed using high-energy synchrotron x-ray radiation combined with electrostatic
levitation (ESL)2.
In parallel, we show a similar phenomenon in a chalcogenide-based glassforming liquid Ge15Te85, where a
fragile-strong transition was discovered near its eutectic melting temperature3. In-situ X-ray scattering data
revealed that the fragile-strong transition is not only related to short-range-order (SRO) structural change,
but also linked to a remarkable development of medium-range-order (MRO)4. The latter manifests as an
emerging pre-peak in total structural factor S(Q) and an atomic pair correlation on the length scale of ~8 Å
in the real-space G(r) function. The fragile-strong transition is also associated with a semiconductor-metal
(SC-M) transition and a density anomaly. Following this line, we examine the electronic conductivity and,
then, SC-M transitions in related alloys including those so-called Phase-Change Materials such as
Ge2Sb2Te5 and Ge1Sb2Te4 which can be reversibly switched between amorphous and crystalline states and
are of technological interests for non-volatile memory devices applications. We find a systematic tendency
in SC-M transitions with the metallicity of alloy components, and conclude that Ge-Sb-Te Phase-Change
Materials possess SC-M (and liquid-liquid) transitions that have become submerged below the liquidus
surface, which controls the liquid-state behavior and has significant impact on application-relevant phase-
switching properties5.
REFERENCES
1. Wei, S. et al. Linking structure to fragility in bulk metallic glass-forming liquids. Appl. Phys. Lett. 106, 181901
(2015).
2. Stolpe, M. et al. Structural changes during a liquid-liquid transition in the deeply undercooled
Zr58.5Cu15.6Ni12.8Al10.3Nb2.8 bulk metallic glass forming melt. Phys. Rev. B 93, 14201 (2016).
3. Wei, S., Lucas, P. & Angell, C. A. Phase change alloy viscosities down to Tg using Adam-Gibbs-equation fittings
to excess entropy data: A fragile-to-strong transition. J. Appl. Phys. 118, 34903 (2015).
4. Wei, S. et al. Structural evolution on medium-range-order during the fragile-strong transition in Ge15Te85. Acta
Mater. 129, 259–267 (2017).
5. Shuai Wei, Coleman, G. J., Lucas, P. & Angell, C. A. Glass Transitions, Semiconductor-Metal Transitions, and
Fragilities in Ge-V-Te (V=As, Sb) Liquid Alloys: The Difference One Element Can Make. Phys. Rev. Appl. 7,
34035 (2017).
Met-Glas-8 ORAL CONTRIBUTIONS
Invited Talk
Liquid-liquid transition of metallic alloys: Why is NMR a
suitable technique for revealing and characterizing LLT
Yue WU
University of North Carolina, Chapel Hill, NC 27599-3255, USA
and
Huazhong University of Science and Technology, Wuhan, China.
From thermodynamic point of view, a liquid (even a single-element liquid) could undergo a
first-order phase transition from one liquid phase to another liquid phase without change of
composition. Such phase transition is called a liquid-liquid transition (LLT). Except a few
cases such as cerium where the electronic state of the element changes drastically with
pressure, LLT remains controversial. It is not obvious what the dominant order parameter
could be associated with LLT. Moreover, since the reported LLTs often reside in the
supercooled region, the possible influence of crystallization effects could become an issue.
Nuclear magnetic resonance (NMR) is shown to be a very sensitive probe for local structural
changes in molten metallic alloys. Such sensitivity is shown to be crucial for identifying key
characteristics associated with LLT such as hysteresis effects. In this talk I will give several
examples of LLTs identified by NMR above the liquidous temperature [1]. It is shown that
the combined information of structure and dynamics obtained by NMR is very effective in
identifying LLT and revealing the possible nature of the associated order parameter.
REFERENCES
1. Xu, W. et al., Evidence of liquid-liquid transition in glass-forming La50Al35Ni15 melt above liquidus
temperature, Nature Communications. 6, 7696 (2015).
ORAL CONTRIBUTIONS Met-Glas-9
Invited Talk
Interstitialcy Theory – a New Approach to the
Understanding of Relaxations in Metallic Glasses
V.A. Khonik
Department of General Physics, State Pedagogical University, Lenin St. 86, Voronezh
394043, Russia
The Interstitialcy Theory (IT) suggested by Granato [1,2] argues that melting of crystalline
metals is related to the rapid generation of interstitial defects in the dumbbell (split) form
called interstitialcies. This hypothesis was supported by recent experiments [3]. Computer
simulation shows that interstitialcies remain identifiable structural units in the liquid state.
Rapid melt quenching freezes these defects in the solid glassy state. Then, relaxation
phenomena in metallic glasses (MGs) can be related to the thermoactivated change of
interstitialcy concentration. The work within the framework of the IT during the past decade
showed that it constitutes a new consistent, clear, and testable approach, which uncovers the
generic relationship between the properties of the maternal crystal, equilibrium/supercooled
liquid and glass. In all cases considered so far, the IT provides either reasonable or rather
exact description of the relaxation kinetics in metallic glasses [4,5].
In particular, the IT quantitatively explains quite a few major relaxation properties of MGs:
nature of the shear softening of glass with respect to the maternal crystal,
kinetics of structural relaxation upon complicated heat treatment,
kinetics of heat release and heat absorption upon structural relaxation below gT , in the
supercooled liquid region and as well as upon crystallization,
relationship between the relaxation of the shear elasticity and heat effects,
relationship between the shear softening, heat effects, anharmonicity of interatomic
interaction and defect structure of metallic glasses,
nature and relaxation change of low temperature Boson heat capacity peak.
REFERENCES
1. Granato, A.V, Interstitialcy model for condensed matter states of face-centered-cubic metals, Phys. Rev.
Lett. 68, 974-977 (1992).
2. Granato, A.V, Interstitialcy theory of simple condensed matter, Eur. J. Phys. 87, 18 (2014).
3. Safonova E V, Mitrofanov Yu P, Konchakov R A, Vinogradov A Yu, Kobelev N P, Khonik V A,
Experimental evidence for thermal generation of interstitials in a metallic crystal near the melting
temperature, J. Phys.: Condens. Matter 28, 215401 (2016).
4. Khonik V A, Understanding of the structural relaxation of metallic glasses within the framework of the
interstitialcy theory, Metals, 5, 504-529 (2015).
5. Khonik V A, Interstitialcy theory of condensed matter states and its application to non-crystalline metallic
materials, Chin. Phys. B 26, 016401 (2017).
Met-Glas-10 ORAL CONTRIBUTIONS
Invited Talk
Activation energy spectrum for relaxation and liquid-liquid
transition in an ultra-viscous metallic glass former
Isabella Gallino
Chair of Metallic Materials, Saarland University, Campus C6.3, 66123 Saarbruecken,
Germany
Bulk metallic glasses are formed from highly viscous, densely packed, multi-component liquids, in
which the sluggish kinetics is the most important factor for impeding the nucleation and growth of
crystals. This is also reflected in a reduced atomic mobility during annealing below the glass
transition, Tg, that can hinder configurational changes at the atomic scale. Recent calorimetric
investigations on the Au49Cu26.9Si16.3Ag5.5Pd2.3 glass former showed the existence of multiple enthalpy
relaxation pathways upon applying a wide range of annealing times, from less than one second up to
several days, during annealing at temperatures of 50 to 20 Kelvin below Tg [1]. The distinct multiple
decays in the enthalpy relaxation correspond to states of local and transient equilibrium with
increasingly higher activation energies. The results are compared with detailed microscopic
information on the collective atomic motion obtained using X-ray Photon Correlation Spectroscopy
(XPCS). Different regimes of stationary dynamics are observed that are separated by intermittent
temporary aging regimes, which facilitate the physical aging towards equilibrium [1]. Each explored
dynamic stationary regime is viewed as corresponding to a thermodynamic local equilibrium with a
distinct activation energy.
Additionally, during long-time annealing in the ultra-viscous state a thermodynamic signature of a
liquid-liquid transition (LLT) is observed [1]. According to ref. [2], the LLT-temperature is slightly
lower than the conventional Tg for this alloy system. The consequence is that the high-temperature
kinetically fragile liquid freezes into the glass during conventional processing and the underlying LLT
is thus accessed by the system during annealing below Tg. The process involves kinetics with
relaxation times of the order of thousands of seconds. The transition is found to be reversible upon re-
heating in DSC, marked by a small value of the ordering enthalpy as well as entropy change (2.4 % of
the entropy of fusion). The weak ordering energy is the reason why the associated transition
temperature is found at a very low temperature. These findings support the ‘big-picture’ proposed by
Angell that liquids with different fragility occupy different flanks of an underlying order-disorder
transition.
REFERENCES
1. Gallino, I., Cangialosi, D., Evenson, Z., Schmitt, L., Hechler, S., Stolpe, M., Ruta, B., Activation energy
spectrum for relaxation and polyamorphism in a ultra-viscous metallic glass former. Subm. (2017).
2. Hechler, S., Ruta, B., Stolpe, M., Pineda, E., Evenson, Z., Gross, O., Hembree, W., Bernasconi, A., Busch,
R., Gallino, I., Liquid-liquid transition revealed by quasi-static cooling of an ultra-viscous metallic liquid.
https://arxiv.org/abs/1704.0670, (2017).
ORAL CONTRIBUTIONS Met-Glas-11
Invited Talk
Intermittent Aging Dynamics in Bulk Metallic Glasses
Zach Evenson
Physik-Department (E13) - Technische Universität München
Maier-Leibnitz Zentrum (MLZ)
Uncovering the microscopic mechanisms that govern aging in metallic glasses will play a
critical role in our ability to design more resilient versions of these amorphous alloys and
ultimately deepen our understanding of the glassy state itself. I will present our recent
discovery of intermittent atomic motion in a metallic glass as revealed through x-ray photon
correlation spectroscopy (XPCS) measurements carried out on the beamline ID10 at the ESRF
in Grenoble [1]. The intermittent aging dynamics in this metallic glass shows striking
similarities to particle motion observed in colloidal gels and even martensitic transitions in
crystalline alloys [2,3]. This suggests that physical aging can be triggered via cooperative
rearrangements of groups of atoms, driven by the relaxation of atomic-level stresses.
Additionally, I will present a detailed comparison with rheological measurements of a Zr-
based bulk metallic glass (BMG), showing that the macroscopic and microscopic aging
behavior of BMGs apparently obey fundamentally different mechanisms, and that traditional
phenomenological models fail to capture this intriguing length scale-dependence. This unique
type of glassy-state dynamics is currently not accounted for in theoretical studies and calls for
a frank re-evaluation of how we envision structural relaxation in metallic glasses.
REFERENCES
1. Evenson, Z., Ruta, B., Hechler, S., Stolpe, M., Pineda, E., Gallino, I., Busch, R., Phys. Rev. Lett. 115,
175701 (2015)
2. Duri, A., Cipelletti, L., Europhys. Lett. 76, 972 (2006)
3. Müller, L., Waldorf, M., Gutt, C., Grübel, G., Madsen, A., Finlayson, T. R., Klemradt, U., Phys. Rev. Lett.
107, 1 (2011)
Met-Glas-12 ORAL CONTRIBUTIONS
Oral
Rich Dynamics in Metallic Glasses: Memory Effect
Manifested by Boson Peak and a New Relaxation
Decoupling at Low Temperatures
Peng Luo and Wei-Hua Wang
Institute of Physics, Chinese Academy of Sciences, Beijing 100190 China
The disorder packing and nonequilibrium character of metallic glass render rich dynamics
with the timescales spanning as large as 30 decades [1]. Memory effect suggests that the state
of a nonequilibrium material can carry an imprint of the past and this memory can affect the
behavior of a material as it evolves further in time. What does a material “know” about its
past? Exploring this question can yield insights into a material’s internal structure and
dynamics. With this in mind, we explored the boson peak evolution along with single- and
double-step isothermal aging and uncovered a new form of the memory capacity in metallic
glasses [2]. We found that single-step aging produces a monotonic decrease of the boson peak
intensity while double-step aging results in a nonmonotonic evolution. This indicates that the
boson peak dynamics constitues a part of the stored information, or memory of the material,
backing the viewpoint that boson peak is associated to the locally heterogeneous structure.
Glassy dynamics is far richer-than-expected, as we recently found in the long-time stress
relaxation of metallic glasses a surprising gradual change of the relaxation profile from a
single-step to a two-step decay upon cooling [3]. This behavior implies a decoupling of the
relaxation in two different processes in glassy state: a faster one likely related to the
anomalous stress-dominated microscopic dynamics, and a slower one associated to sub-
diffusive motion at larger scales with a broader distribution of relaxation times.
REFERENCES
1. Luo, P., Lu, Z., Li, Y. Z., Bai, H. Y., Wen, P., Wang, W. H., Probing the evolution of slow flow dynamics
in metallic glasses, Physical Review B 93, 104204 (2016).
2. Luo, P., Li, Y. Z., Bai, H. Y., Wen, P., Wang, W. H., Memory effect manifested by a boson peak in metallic
glass, Physical Review Letters 116, 175901 (2016).
3. Luo, P., Wen, P., Bai, H. Y., Ruta, B., Wang, W. H., Relaxation decoupling in metallic glasses at low
temperatures, Physical Review Letters, accepted.
ORAL CONTRIBUTIONS Met-Glas-13
Oral
Gamma-relaxation in bulk metallic glasses
Stefan Küchemann, Robert Maaß
Department of Materials Science and Engineering, University of Illinois at Urbana-
Champaign, 1304 West Green Street, Urbana 61801 IL, USA
Bulk metallic glasses relax to more stable low enthalpy configurations when exposed to
elevated temperatures below the glass transition. In contrast, during thermal cycling at
cryogenic temperatures, metallic glasses were observed to explore higher enthalpy states. One
hypothesis of this cryogenic rejuvenation process includes locally compressed and dilated
regions driven by heterogeneous thermal expansion. Here we show in dynamic mechanical
excitation experiments that the low temperature rejuvenation process can be linked to a third
general relaxation process, which we term γ-relaxation [1]. Contrary to the previously known
primary α- and secondary β-relaxation close to the glass transition, this low energy excitation
causes a significant macroscopic rejuvenation, which we assign to non-affine atomic
rearrangements in the matrix that are driven by thermal stress during cooling.
REFERENCES:
1. Küchemann, S., Maaß, R., "Gamma relaxation in bulk metallic glasses." Scripta Materialia (2017), in press,
and preprint arXiv:1703.09016 (2017)
Met-Glas-14 ORAL CONTRIBUTIONS
Invited Talk
Spectra of Shear Transformation Zones from Anelastic
Relaxation – A Quantitative Probe of the State of Metallic
Glasses
Michael Atzmon,1,2
Tianjiao Lei,2 Luis Rangel DaCosta,
2 M. Liu
3 and W. H.
Wang3
1Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann
Arbor, Michigan, 48109-2104, U. S. A.
2Department of Materials Science and Engineering, University of Michigan, Ann Arbor,
Michigan, 48109-2136, U. S. A.
3Chinese Academy of Sciences, Institute of Physics, Beijing 100190, People’s Republic of
China
Time-dependent deformation of glasses is believed to be accommodated by equiaxed clusters,
which undergo irreversible shear within an elastic matrix matrix [1]. While such clusters, known
as shear transformation zones (STZs), cannot be imaged with currently known methods, we have
been able to identify their signature, and resolve them by size, using quasi-static anelastic
relaxation experiments and relaxation-time spectra computed from these. We observed an
atomically quantized hierarchy of STZs [2,3], as implied by distinct peaks in the spectra, each
corresponding to a specific number of atoms. The size distribution of potential STZs was obtained
from the spectra. We also showed that both alpha and beta mechanical relaxations are
accommodated by STZs, where the latter are due to small STZs, which transform at higher rates
[4].
In an effort to understand the origin of ductility, since the ductility of metallic glasses has been
correlated with intense beta relaxations in internal friction [5], we have measured the anelastic
relaxation spectra of two similar alloys: La70Ni15Al15 and La70Cu15Al15. These will be presented
and discussed. We find that structural relaxation at room temperature leads to significant changes
of the number of potential STZs. This observation offers us an opportunity to characterize
structural relaxation in unprecedented detail, resolving its effect on the size distribution of
potential STZs.
REFERENCES
1. Argon, A. S., Acta Metall. 27, 47-58 (1979).
2. Ju, J. D., Jang, D., Nwankpa, A., Atzmon, M., J. Appl. Phys. 109, 053522 (2011).
3. Ju, J. D., Atzmon, M., Acta Mater. 74, 183-188 (2014).
4. Ju, J. D., Atzmon, M., MRS Comm. 4, 63-66 (2014).
5. H. B. Yu, X. Shen, Z. Wang, L. Gu, W. H. Wang, and H. Y. Bai, Phys. Rev. Lett. 108, 015504, (2012).
ORAL CONTRIBUTIONS Met-Glas-15
Invited Talk
Dynamical, structural and chemical heterogeneities in a
binary metallic glass-forming liquid
F. Puosi, N. Jakse, A. Pasturel
Sciences et Ingénierie des Matériaux et Procédés, UMR 5266 CNRS, Université Grenoble
Alpes (UGA), 1130 rue de la Piscine, BP 75, 38402 Saint-Martin d’Hères Cedex, France
In the present work we use classical molecular dynamics simulations to study the connections
between atomic dynamics and microscopic structure of Cu50Zr50 alloy in the supercooling
regime. Dynamical heterogeneities are identified via an isoconfigurational analysis [1]. As
deeper supercooling is achieved a transition from isolated to clustering low mobility atoms is
reported. These slow clusters, whose size grow upon cooling, consist of a Zr-enriched phase,
with a composition of that of the compound CuZr2, which is known to form as the primary
crystalline phase from the undercooled liquid below 800K. In addition, a structural analysis of
slow clusters based on Voronoi tessellation evidences an increase with respect of the bulk
system of the fraction of Cu atoms having a local icosahedral order. These results are in
agreement with the consolidated scenario of the relevant role played by icosahedral order in
the dynamic slowing-down in supercooled metal alloys [2].
REFERENCES
1. Widmer-Cooper, A., Harrowell, P., Fynewever, H., How reproducible are dynamic heterogeneities in a
supercooled liquid?, Phys. Rev. Lett. 93, 185701 (2004).
2. Lad, K.N., Jakse, N., Pasturel, A., Signatures of fragile-to-strong transition i a binary metallic glass-forming
liquid, J. Chem. Phys 136, 104509 (2012).
Met-Glas-16 ORAL CONTRIBUTIONS
Invited Talk
Icosahedral medium-range order and its effect on
relaxation dynamics in CuZr metallic glass-forming liquids
Maozhi Li
Department of Physics, Renmin University of China, Beijing 100872 China
The correlation between structural relaxation and the medium-range structures formed by
icosahedral cluster packing in CuZr metallic glass-forming liquids was studied via molecular
dynamics simulations. It is found that the icosahedral medium-range structures play more
important and controlling roles in the structural relaxation process of the metallic liquids. The
relaxation times of local structures depend exponentially on the connectivity of local
structures1. Scaling analysis based on percolation theory reveals that the size distribution of
clusters formed by the central atoms of icosahedra at various temperatures follows a very
good scaling law, which suggests that there would be a structural phase transition manifested
by percolation of locally favored structures underlying the glass transition2. Furthermore, it is
revealed that when icosahedral short-range order (ISRO) extends to medium-range length
scale by connection, the atomic configurations of ISROs will be optimized from distorted
ones towards more regular ones gradually, which significantly lowers the energies of ISROs
and introduces geometric frustration simultaneously2. Both factors make key impacts on the
drastic dynamic slow-down of supercooled liquids. Our findings provide direct structure-
property relationship for understanding the nature of glass transition.
REFERENCES
1. Wu, Z. W., Li, M. Z., Wang, W. H., Liu, K. X., Correlation between structural relxation and connectivity of
icosahedral clusters in CuZr metallic glass-forming liquids, Phys. Rev. B 88, 054202 (2013).
2. Wu, Z. W., Li, F. X., Huo, C. W., Li, M. Z., Wang, W. H., Liu, K. X., Critical scaling of icosahedral
medium-range order in CuZr metallic glass-forming liquids, Sci. Rep. 6, 35967 (2016).
ORAL CONTRIBUTIONS Met-Glas-17
Invited Talk
Inter-diffusion and its correlation with dynamical cross
correlation in liquid Ce80Ni20
Bo Zhang
Institute of Amorphous Matter and Science & Laboratory of Diffusion of Liquid Metal,
School of Materials Science and Engineering, Hefei University of Technology,
Hefei 230009, China
The inter-diffusion coefficients of Ce-Ni were measured in liquid Ce80Ni20 alloys by sliding
cell method. The results indicate that the inter-diffusion strongly deviated from the standard
Darken prediction and the relationship between inter-diffusion and self-diffusion should be
described by the Darken–Manning equation. The dynamical cross correlation factor S of this
liquid alloys is in the range of 0.6~0.8, which is much different from the solid where the S
factor is always lager than 1. The linear response theory shows that the dynamical cross
correlation factor is closely related with the distinct diffusion coefficients, or rather the
deviation parts of the distinct diffusion coefficients to the reference diffusion system. In
Ce80Ni20 melts, the abnormally small S was directly originated from the enhanced Ce-Ni
distinct diffusion and reduced Ni-Ni distinct diffusion. The different mixing and movement
tendencies of dynamical behaviors in real liquid diffusion system is largely due to the
“chemical” interactions among atoms. In the Ce80Ni20 alloy melts, the heterogeneity of
dynamics caused by the chemical interactions makes the distinct diffusion of Ce-Ni and Ni-Ni
deviate from the ideal diffusion behaviors, and finally leads to the failure of the Darken
formula.
REFERENCES
1. Hu, J. L., Zhong, L. X., Zhu, C. A., Zhang, B., Inter‐diffusion and its correlation with dynamical cross
correlation in liquid Ce80Ni20, Appl. Phys. A. 123, 176 (2017).
Met-Glas-18 ORAL CONTRIBUTIONS
Oral
Can homogenous nucleation be controlled in a metallic
glass?
Bin Yang1,2
, Yulai Gao3, Christoph Schick
1,2
1Institute of Physics, University of Rostock, Albert-Einstein Str. 23-24, 18051 Rostock,
Germany
2Competence Centre CALOR, Faculty of Interdisciplinary Research, University of Rostock,
Albert-Einstein-Str. 25, 18059 Rostock, Germany.
3State Key Laboratory of Advanced Special Steels, Shanghai University, 149 Yanchang Road,
200072 Shanghai, PR China
Fast scanning chip calorimetry was successfully employed to not only suppress crystallization
but also bypass homogeneous nucleation of an Au-based bulk metallic glass on controlled fast
quenching. A truly amorphous metallic glass without homogeneous nucleation was acquired.
Following the rapid quenching, annealing at different temperatures from 0.001 s to 10000 s
was realized, in which homogeneous nucleation was allowed and various local-configurations
were obtained consequently. Its effect on crystallization was quantified based on the evolution
of enthalpy employing nuclei development approach. Finally, a C-curve illustrating the
homogeneous nucleation kinetics was obtained and added to the conventional TTT diagram,
by which a truly amorphous state and the kinetics of homogeneous nucleation can be
estimated. The art to control homogeneous nucleation and the science to uncover the
corresponding mechanism provide new insights how to tune the micro- to nano-structure of
metallic glasses, and facilitates the understanding of solidification and glass forming ability
both in engineering and scientific fields.
ORAL CONTRIBUTIONS Met-Glas-19
Invited Talk
Fast relaxation versus emergence of medium range order in
metallic glasses
D. Crespo, P. Bruna and E. Pineda
Department of Physics, Universitat Politècnica de Catalunya, Campus del Baix Llobregat,
Castelldefels, Catalunya
The relaxation spectrum of metallic glasses shows successive relaxation processes – α, β, β’ –
of decreasing activation energy and characteristic time. It is commonly accepted that each of
these processes involves a decreasing number of atoms, and thus it is debatable if this cascade
of relaxations is already complete or there are still faster, lower energy relaxation processes
which fall below the limits of experimental measurement.
Molecular dynamics simulation of good metallic glass formers – Pd82Si18 and Zr50Cu40Al10 –
showed an unexpected hardening of the phase sound speed in the nm range, independent of
the glass quenching rate [1]. This behaviour was attributed to a hardening of the shear
modulus in the Thz range, at the end of the Boson peak region. The subsequent, very fast
relaxation may be responsible for the anomalies found in Inelastic X-Ray measurements of
the sound speed.
Here we present new results of similar simulations of a poor glass-former alloy – Pd50Cu50.
The simulation results show a similar trend as the one obtained for the alloys with high glass-
forming ability, but in this case the hardening frequency significantly decreases with the
quenching rate. This result is connected to the emergence of medium range order in the glass
as a consequence of the onset of the crystallization process and it allows us to discuss the
structural origin of the fast relaxation
REFERENCES
1. Crespo, D., Bruna, P., Valles, A., and Pineda, E., Phys. Rev. B 94, 144205, 2016
Met-Glas-20 ORAL CONTRIBUTIONS
Invited Talk
Jerky Flow Behavior in Bulk Metallic Glasses
G. Wang1, J.L. Ren
2, P.K. Liaw
3
1Laboratory for Microstructures, Institute of Materials, Shanghai University, Shanghai
200444, China
2School of Mathematics and Statistics, Zhengzhou University, Zhengzhou 450001, China
3Department of Materials Science and Engineering, The University of Tennessee, Knoxville,
TN 37996, USA
Bulk metallic glasses (BMGs) usually exhibit a discontinued serrated plastic flow behavior
after yielding. In this plastic flow, each serration event includes elastic energy accumulation
and relaxation, which corresponds to shear bands formation and propagation. The shear band
randomly forms on the sample surface and propagates at a very high velocity, which brings
out that the distribution of the amplitude of serration events in the plastic flow is
inhomogeneous. Since that, the quantitative description of the serrated flow behavior is
difficult. Therefore, in the proposed project, we will use the statistic analysis to investigate the
plastic dynamics of BMGs. Through changing the loading condition (including strain rate and
environmental temperature) and the microstructure (including fully amorphous and the
nanocrystal/glass binary phase structures) of BMGs, we will disturb the plastic dynamics and
then explore the dynamics evolution process in the spatio and temporal frame. The structural
evolution of BMGs will be in-situ observed in a high resolution microscope accompanied
with diffraction technique. Digital scattering correlation method will be applied to explore the
strain field distribution at the yielding point. Based on shear transformation zone theory, the
correlation between plastic strain render medium distribution and plastic dynamics will be
elucidated.
REFERENCES
1. Tong, X., Wang, G., et al., Shear avalanche in plastic deformation of a metallic glass composite,
International Journal of Plasticity. 77, 141-155 (2016).
2. Bian, XL., Wang, G., et al., Manipulation of free volumes in a metallic glass through Xe-ion irradiation,
Acta Materialia. 106, 66-77 (2016).
3. Ren, JL,et al., Plastic Dynamics Transition between Chaotic and Self-Organized Critical States in a Glassy
Metal via a Multifractal Intermediate, Physical Review B. 86, 134303 (2012).
ORAL CONTRIBUTIONS Met-Glas-21
Invited Talk
Nonlinear Response and Avalanche Behavior in Metallic
Glasses
B. Riechers, and K. Samwer
I. Physikalisches Institut, Georg-August-Universität Göttingen,
Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
Experimental results are presented which compare the global nonlinear response of a metallic
glass to the same data analyzed in terms of avalanche statistics.
Samples of Pd40Ni40P20 are analyzed using a dynamic mechanical analyzer in single cantilever
mode at temperatures slightly below the glass transition temperature. The metallic glass is
excited by a controlled sinusoidal stress of 1 Hz frequency with high field amplitudes.
During the initiation of the experiment the stress amplitude is relatively low and thus in a
regime considered as linear in the stress-strain-curve of the material. By increasing the stress-
amplitude from one period to another, the sample is exposed to a high field. By a period-by-
period Fourier-analysis, the evolution of nonlinear contributions to the first harmonic and the
emergence of additional odd harmonics with time is revealed, similar as in preceding
experiments using dielectric spectroscopy on amorphous media by Richert [1]. The timescale
of the evolution of nonlinearity is connected to the structural relaxation time of the material,
suggesting a long-range interaction between relaxation modes.
An incremental analysis approach on the highly resolved strain data yields a very different
sight on elastic and plastic response regimes. Independent of low or high field amplitude,
power-law behavior in strain response distributions identifies the full investigated range of
temperatures and stresses to be connected to a superposition of elastic and plastic response.
These findings question the differentiation between linear and nonlinear regimes as derived
from the nonlinear analysis and confirm the microscopic view on elastic and plastic sample
response to mechanical fields which is based on shear transformation zones, which result due
to their cooperative behavior in the observation of avalanches [2,3].
REFERENCES
1. Richert, R., Weinstein, S., Nonlinear Dielectric Response and Thermodynamic Heterogeneity in Liquids,
Physical Review Letters. 97, 095703 (2006).
2. Krisponeit, J.-O., Pitikaris, S., Avila, K. E., Küchemann, S., Krüger, A., Samwer, K., Crossover from
random three-dimensional avalanches to correlated nano shear bands in metallic glasses, Nature
Communications 5, 2013
3. Herrero-Gómez, C., Samwer, K., Stress and temperature dependence of the avalanche dynamics during
creep deformation of metallic glasses, Scientific Reports 6 (2016)
Met-Glas-22 ORAL CONTRIBUTIONS
Invited Talk
Aging dynamics around a shear band in metallic glasses
Robert Maass
Department of Materials Science and Engineering, University of Illinois at Urbana-
Champaign, Urbana, IL 61801, USA
Strain localization into shear bands in metallic glasses (MGs) has long sought to be a
phenomenon confined to the nano-scale [1], but recent work highlights that shear bands
induce a position-dependent long-range signature that originates from residual stresses [2,3,4]
or potentially from structural changes [5]. Here we using site-specific x-ray photon
correlation spectroscopy to unravel the structural dynamics around a shear band and compare
this to the undeformed bulk material [6]. We show that damage accumulation into a shear
band leads to significantly accelerated relaxation dynamics at length scales three orders of
magnitude larger than the core of the shear band. The ten-times-faster dynamics in the shear-
band vicinity compared to the as-cast matrix occurs in a characteristic three-stage aging
regime, which manifests itself in the temperature-dependent shape parameter known from
classical stretched exponential relaxation dynamics of disordered materials. We demonstrate
that the time-dependent correlation functions describing the aging at different temperatures
can be captured and collapsed using simple scaling functions. Based on the specific aging
regimes, it becomes possible to rationalize a general crossover from stretched to compressed
exponential relaxation dynamics for a MG that undergoes aging after being quenched from
the liquid into a solid. These insights highlight how an ubiquitous nano-scale strain-
localization mechanism in MGs leads to fundamental changes of the material at the
mesoscale.
REFERENCES
1. Maass, R., Löffler, J.F., Shear-Band Dynamics in Metallic Glasses, Advanced Functional Materials 25
(2015) 2353–2368.
2. Maass, R., Samwer, K., Arnold, W., Volkert, C.A., A single shear band in a metallic glass: Local core and
wide soft zone, Applied Physics Letters 105 (2014) 171902.
3. Maass, R., Birckigt, P., Borchers, C., Samwer, K., Volkert, C.A., Long range stress fields and cavitation
along a shear band in a metallic glass: The local origin of fracture, Acta Materialia 98 (2015) 94-102.
4. Shakur Shahabi, H., Scudino, S., Kaban, I., Stoica, M., Escher, B., Menzel, S., Vaughan, G. B. M., Kühn,
U., Eckert, J., Mapping of residual strains around a shear band in bulk metallic glass by nanobeam X-ray
diffraction, Acta Materialia 111 (2016) 187-193.
5. Pan, J., Chen, Q., Liu, L., Li, Y., Softening and dilatation in a single shear band, Acta Materialia 59 (2011)
5146-5158.
6. Küchemann, S., Liu, C., Dufresne, E., Shin, J., Maass, R., Three-stage aging dynamics around a shear band
in metallic glasses, under review (2017).
ORAL CONTRIBUTIONS Met-Glas-23
Invited Talk
Structural transition upon vitrification in viscous metallic
liquids
Isabell Jonas, Fan Yang, Andreas Meyer
Institute of Materials Physics in Space, German Aerospace Center, 51147 Cologne
We investigate vitrification of bulk-glass forming Zr-Ni-Cu-Ti-Be and Zr-Cu-Ni-Al-Nb
liquids from the equilibrium melt to the glass transition in-situ with container-less processing.
Electrostatic levitation gives access to the measurement of temperature, density, viscosity and
in combination with X-ray diffraction to the total structure factor. Free radiation cooling of
the sample allows the measurement of the specific heat over constant emissivity of the
sample, which exhibits a pronounced peak in the deeply undecooled melt. This comes along
with a change in the temperature dependence of the position of the first sharp diffraction peak,
whereas the thermal expansion of the sample does not exhibit a detectable change over the
entire temperature range [1,2]. In addition, indirect information on the specific heat of the
sample is obtained by precise measurement of the required heating laser power [3]. All
measurements reveal a consistent onset of changes in the total structure factor and the specific
heat with no detectable cooling rate dependence. Results are discussed in the context of
liquid-liquid phase transitions and the mode coupling theory of the liquid to glass transition.
REFERENCES
1. S. Wei, F. Yang, J. Bednarcik, I. Kaban, O. Shuleshova, A. Meyer, R. Busch, Nature Comm. (2013)
2. M. Stolpe, I. Jonas, S. Wei, W. Hambree, Z. Evenson, F. Yang, A. Meyer, R. Busch, PRB (2016)
3. I. Jonas, F. Yang, A. Meyer, et al., to be published
Met-Glas-24 ORAL CONTRIBUTIONS
Oral
Structural and dynamical evolution in La-based glasses and
melts
Zheng WANG1, Fan YANG
1 and Andreas MEYER
1
1 Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt
(DLR), 51170 Köln, Germany
The limited plasticity before catastrophic failure is a long-standing conundrum hindering the
wide application of metallic glasses (MGs). Recent study found that the local relaxation
behavior can strongly affect the heterogeneous deformation in MGs, which can even govern
their mechanical performance at room temperature [1]. Furthermore, the local relaxation
behavior is also considered to be related to regions in MGs exhibiting weak bonding and large
amount of free volume. Therefore, tuning the local relaxation behavior may provide a
practical option to optimize the mechanical performance of MGs. For La-(Ni,Co)-Al MGs,
replacing transition metals (TM) Ni and Co with similar sized Cu results in a different local
relaxation behavior, where a separate beta-relaxation peak in the glass state vanishes [2]. The
reason behind it is still unclear yet but is suspected to be related with chemical interaction and
local packing effects.
In this study, we measured density and total structure factor of these La-based glass-forming
melts using the newly developed containerless electrostatic levitation (ESL) [3], trying to find
out some clue rooted in their liquid structures. We found interestingly a positive excess
volume in the binary La-Cu melts, in contrast to the negative excess volume in La-Ni/Co
melts. The La60Cu40 liquid exhibits also a considerably different total structure factor S(q)
compared to that of the La60(Ni/Co)40 melts, measured with the X-ray synchrotron diffraction.
Both the specific volume and the reverse Monte Carlo simulation on measured S(q) suggest a
looser packing in La-Cu-(Al) than in La-(Ni,Co)-(Al) melts, which might be related to the
change of the relaxation behavior in the ternary La-TM-Al glasses.
REFERENCES
1. Wang, Z., Sun, B. A., Bai, H. Y., Wang, W. H., Nat. Commun., 5, 5823 (2014).
2. Wang, Z., Yu, H. B., Wen, P., Bai, H. Y., Wang, W. H., J. Phys. Condens. Matter, 23, 142202 (2011).
3. Holland-Moritz, D., Yang, F., Kordel, T., Klein, S., Kargl, F., Gegner, J., Hansen, T., Bednarcik, J., Kaban,
I., Shuleshova, O., Mattern, N., Meyer, A., EPL, 100, 56002 (2012).
ORAL CONTRIBUTIONS Met-Glas-25
Oral
Tune metallic glasses anisotropy by asymmetric mechanical
cycling
B.S.Shang1,P. F. Guan
1,and W. H. Wang
2
1Beijing Computational Science research center,Beijing 100094, China
2Institute of Physics,Chinese Academy of Sciences,Beijing 100190, China
Metallic glasses, as a kind of fancy amorphous solid, have a ultrahigh elastic limit but lack of
plastic deformation ability. To extend the application prospect of metallic glasses as structural
material, it is worth developing a method to modify mechanical property within elastic limit.
Thus, anisotropy, a notable mechanical property in metallic glasses, has aroused more and
more interesting, however, a valid method to modify anisotropy effectively and the atomic
mechanism of anisotropy are still elusive. Here, by employing a novel asymmetric mechanical
cycling model, we tune metallic glasses to elastic anisotropy effectively, but not change
sample significantly, and furthermore, find that macro anisotropy is come down to the local
yield stress asymmetry. Based on potential energy landscape, the asymmetry is ascribed to
back stress redistribution in metallic glasses, and moreover, the trigger of redistribution is
related to nonaffine deformation during training which is localized and heterogeneous. Our
finds show that atomic origin of elastic anisotropy and provide a new perspective to
investigate the mechanical properties of metallic glasses.
REFERENCES
1. Sun, Y., Concustell, A. ,Greer, A. L. Thermomechanical processing of metallic glasses: extending the range
of the glassy state,Nature Reviews Materials, 16039(2016)
2. Patinet, S.,Vandembroucq, D.,Falk, M. L. Connecting Local Yield Stresses with Plastic Activity in
Amorphous Solids,Phys. Rev. Lett., 117, 045501(2016)
3. Sun, Y. H.,Louzguine-Luzgin, D.,Ketov, S.,Greer, A. Pure shear stress reversal on a Cu-based bulk metallic
glass reveals a Bauschinger-type effec, Journal of Alloys and Compounds , 615(2014)
Met-Glas-26 ORAL CONTRIBUTIONS
Invited Talk
Fast surface dynamics in metallic glasses
Wei-Hua WANG
Institute of Physics, Chinese Academy of Sciences, Beijing 100190 China
The surface viscosity and self-diffusion of a Pd-based metallic glass were measured using
annealing-induced decay of its surface submicron gratings. Strong surface dynamics and
surface diffusion with the value of more than 105 times faster than bulk diffusion are found at
below glass transition temperature. The high surface dynamic induces a fast crystallization
below glass transition temperature at the free surface which is more than 100 times faster than
that in bulk, higher electrocatalytic activity and unique self-stabilizing catalytic performance
over a long-cycling life than the commercial Pt/C catalysts in Pd-based MGs, and generation
of the modulated superlattice-like nanostructure modulated nanostructure from the surface to
interior. The observations have implications for understanding the glassy surface dynamics,
and pave a way for controllable fabrication of unique and sophisticated nanostructure on glass
surface to realize the properties modification.
REFERENCES
1. Cao, C. R., Huang, K. Q., Zhao, N. J., Sun, Y. T., Bai, H.Y., Gu, L., Zheng, D. N., Wang, W. H., Ultrahigh
Stability of Atomically Thin Metallic Glasses. Appl. Phys. Lett. 105, 011909 (2014)
2. Chen, L., Cao, C. R., Shi, J. A., Lu, Z., Sun, Y. T., Luo, P., Gu, L., Bai, H. Y., Pan, M. X., Wang, W. H.,
Fast surface dynamics of metallic glass enable superlattice-like nanostructure growth. Phys. Rev. Lett. 118,
016101 (2017)
3. Hu, Y. C., Wang, Y. Z., Su, R., Cao, C. R., Li, F., Sun, C. W., Yang, Y., Guan, P., Ding, D. W., Wang, Z.
L., Wang, W. H., A Highly Efficient and Self-stabilizing Metallic Glass Catalyst for Electrochemical
Hydrogen Generation. Adv. Mater. 28, 10293–10297 (2016)
ORAL CONTRIBUTIONS Nonlin-Dyn-1
Invited Talk
Unifying different interpretations of the nonlinear response
in glass-forming liquids
S. Albert1,*
, P. Gadige1,**
, M. Michl2, Th. Bauer
2,***, P. Lunkenheimer
2, A.
Loidl2, R. Tourbot
1, C. Wiertel-Gasquet
1, G. Biroli
3,4, J.-P. Bouchaud
5, F.
Ladieu1
1SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay Bat 772, 91191 Gif-sur-Yvette Cedex, France.
2Experimental Physics V, Center for Electronic Correlations and Magnetism, University of Augsburg, 86159
Augsburg, Germany.
3IPhT, CEA, CNRS, Université Paris-Saclay, CEA Saclay Bat 774, 91191 Gif-sur-Yvette Cedex, France.
4LPS, Ecole Normale Supérieure, 24 rue Lhomond, 75231 Paris Cedex 05, France.
5Capital Fund Management, 23 rue de l’Université , 75007 Paris, France.
*Present address : Laboratoire de Physique (UMR 5672), ENS de Lyon 46, allée d’Italie, F-69364 Lyon Cedex
07, France
**Present address: Complex Fluids Lab, Soft Condensed Matter Group, Raman Research Institute, CV Raman
Avenue, Sadashivanagar,Bangalore 560080, India
***Present address: Institute for Machine Tools and Industrial Management, Technical University of Munich,
85748 Garching, Germany.
Several interpretations of non-linear susceptibilities in supercooled liquids coexist in the recent
literature. We present experimental data for both Glycerol and Propylene Carbonate, where we
measured three independent cubic susceptibilities. The fact that both their modulus and phases have
very similar temperature and frequency dependences strongly suggests that they origin from a
common mechanism. Therefore, a unique physical mechanism has to be responsible for the growth of
all these non-linear susceptibilities.
We review several different models that have recently been proposed to interpret the non-linear
behavior of supercooled liquids and show that a key ingredient in all of them is the (explicit or
implicit) introduction of the notion of cooperatively rearranging glassy domains.
Focusing on the interpretative framework proposed by Bouchaud and Biroli [1], we show that while it
does not provide a specific mechanism that gives rise to these non-linear responses, it is able to
account for all the salient experimental features by using this main ingredient.
This new understanding of what makes these models so similar and allow them to reproduce the main
experimental features should pave the way for future experiments and allow us a better understanding
of glasses.
REFERENCES
4. Bouchaud, J.-P., Biroli, G., Nonlinear susceptibility in glassy systems: A probe for cooperative dynamical
length scales, Phys. Rev. B 72, 064204 (2005)
Nonlin-Dyn-2 ORAL CONTRIBUTIONS
Invited Talk
Nonlinear Dielectric Effects in Liquids: A Guided Tour
Ranko Richert
School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, USA
The area of nonlinear dielectric effects began with Debye's work with only one contribution to
worry about: saturation, manifested as reduction of the dielectric constant, s, as the electric
field is increased [1]. The work of Piekara [2] added the chemical effect, an increase in s that
originates from the equilibrium of two species with different dipole moments. Dielectric hole
burning and its derivatives demonstrated that the energy absorbed from a field can accelerate
dynamics, even when the temperature remains constant [3]. Finally, strong external fields can
slow down the relaxation times of polar liquids, a feature that has recently been associated
with entropy reduction [4]. The overall field effect amounts to amplitudes increasing and/or
decreasing, and the loss spectrum being shifted to the left and/or right.
The aim of this talk is to provide a guided tour through this jungle of nonlinear dielectric
effects that can occur. The various experimental approaches will be outlined, as well as how
different field protocols can be exploited to discriminate among the different sources of
deviations from a linear dependence of polarization P on the external electric field E.
Experimental examples for each of the effects will be shown, and the level of understanding
for each case will be discussed.
One point of focus is the electrorheological effect observed in simple polar liquids, i.e., the
increased relaxation time (or viscosity) of the liquid as a static field is applied [4]. It is argued
that the extent of this effect is correlated with the amount of field induced entropy change. By
vitue of a simple phenomenological model, it is demonstrated that this entropy effect is a
major contribution to the cubic susceptibility spectra and their dependence on temperature [5].
REFERENCES
1. Debye, P., Polar molecules (Chemical Catalog Company, New York, 1929).
2. Piekara, A., Piekara, B., Saturation électrique dans les liquides purs et leurs mélanges, Compt. Rend. Acad.
Sci. (Paris) 203, 852 (1936).
3. Huang, W., Richert, R., Dynamics of glass-forming liquids. XIII. Microwave heating in slow motion, J.
Chem. Phys. 130, 194509 (2009).
4. S. Samanta and R. Richert, "Electrorheological source of nonlinear dielectric effects in molecular glass-
forming liquids," J. Phys. Chem. B 120, 7737 (2016).
5. Kim, P., Young-Gonzales, A. R., Richert, R., Dynamics of glass-forming liquids. XX. Third harmonic
experiments of non-linear dielectric effects versus a phenomenological model, J. Chem. Phys. 145, 064510
(2016).
ORAL CONTRIBUTIONS Nonlin-Dyn-3
Invited Talk
Nonlinear dielectric spectroscopy in supercooled liquids
M. Michl,1 T. Bauer,
1 S. Albert,
2 F. Ladieu,
2 J.-B. Bouchaud,
3 G. Biroli,
4
P. Lunkenheimer,1 and A. Loidl
1
1Experimental Physics V, Center for Electronic Correlations and Magnetism, University of
Augsburg, 86135 Augsburg, Germany
2SPEC, CEA, CNRS, University Paris-Saclay, 91191 Gif sur Yvette Cedex, France
3Capital Fund Management, 23 rue de l’Université, 75007 Paris, France
4IPHT, CEA, CNRS, University Paris-Saclay, 91191 Gif sur Yvette Cedex, France
Theory and experiments on spin glasses [1], and orientational glasses [2] have taught us that
linear response is blind to hidden order in amorphous matter and that nonlinear
susceptibilities may reveal the critical dynamics governing glassy freezing. Hence, in recent
years the investigation of the nonlinear dielectric response of glass-forming matter is
attracting increasing interest (see, e.g.,[1,2,3,4,5,6]).
We summarize the recent experimental status in non-linear dielectric spectroscopy on
supercooled liquids. Nonlinearity can be measured by comparing the complex high- and low-
field permittivities or by the determination of the higher harmonics of the permittivity.
Performing high-precision nonlinear dielectric experiments on glycerol and propylene
carbonate, we find experimental evidence for increasing cooperativity, implying growing
clusters with correlated molecules on approaching the glass transition. We were able to
demonstrate that the number of dynamically correlated particles increases in much the same
way as the effective energy barrier, as predicted fifty years ago by Adam and Gibbs. By
comparing third and fifth order susceptibilities, we again document the increase of amorphous
order on decreasing temperatures. Moreover, we were able to determine the fractal dimension
of the growing clusters. We find that they are compact and thus the glass transition can be
regarded as a critical phenomenon, different from canonical phase transitions.
REFERENCES
1. Binder K. and Young A.P., Rev. Mod. Phys. 58, 801 (1986).
2. Hemberger J. et al., Phys. Rev. Lett. 76, 2330 (1996).
3. Richert R. and Weinstein S., Phys. Rev. Lett. 97, 095703 (2006).
4. Crauste-Thibierge C. et al., Phys. Rev. Lett. 104, 165703 (2010).
5. Bauer Th. et al., Phys. Rev. Lett. 110, 107602 (2013).
6. Bauer Th. et al., Phys. Rev. Lett. 111, 225702 (2013).
7. Michl M. et al., Phys. Rev. Lett. 114, 067601 (2015).
8. Albert S. et al., Science 352, 1308 (2016).
Nonlin-Dyn-4 ORAL CONTRIBUTIONS
Invited Talk
Modeling the nonlinear dielectric response
Uli Buchenau
Forschungszentrum Jülich, Postfach 1913, D-52425 Jülich, Germany
The recently developed pragmatical model of asymmetric double-well potentials with a finite
lifetime is applied to nonlinear dielectric data in polar undercooled liquids. The viscous
effects from the finite lifetime provide a crossover from the cooperative jumps of many
molecules at short times to the motion of statistically independent molecules at long times.
The model reproduces measured nonlinear spectra, but only if one omits the Onsager factor in
the calculation of the 3ω-signal for glycerol and propylene carbonate.
ORAL CONTRIBUTIONS Nonlin-Dyn-5
Invited Talk
Nonequilibrium transitions in strained glasses
Peter Schall
Institute of Physics, University of Amsterdam
Strained amorphous materials show intriguing mechanical properties that are of fundamental scientific
interest and of great importance for applications. Recent years have witnessed exciting universal
scaling relations that are believed to underlie the nonlinear response of amorphous materials to applied
strain. While largely supported by simulations, experimental model systems have been powerful to
directly visualize and measure these internal scaling relations, and bridge from particle to macroscopic
scale. In particular, colloidal and granular model systems have advanced our understanding of the
internal relaxation mechanisms by direct imaging of the internal structure and dynamics. The
emerging picture is that flow and flow instabilities are related to non-equilibrium phase transitions
from a solid to a liquid-like response of the material.
In this talk, I will present experimental evidence from colloidal and granular systems: the direct
imaging of particle dynamics together with macroscopic stress measurements reveal intriguing
signatures of first and second-order transitions in the deformation of soft amorphous materials. In
particular, we identify the yielding of glasses to a linear strain ramp (constant strain rate) as
percolation transition [1,2], while we find the transition from the linear to the non-linear regime under
oscillatory probing exhibits hallmarks of a first-order transition [3,4], as shown theoretically [5] and
observed in quasistatic simulations [6]. Flow instabilities like the well-known shear banding transition
appear also related to a first-order transition [7,8]. I will present experimental insight, and discuss in
how far the observed phenomena could be universal.
REFERENCES
1. Ghosh, A., Budrikis, Z., Chikkadi, V., Sellerio, A. L., Zapperi, S., and Schall, P., Direct Observation of
Percolation in the Yielding Transition of Colloidal Glasses, Phys. Rev. Lett. 118, 148001 (2017).
2. Denisov, D. V., Lorincz, K. A., Uhl, J. T., Dahmen, K. A., and Schall, P., Universality of slip avalanches in
flowing granular Matter, Nature Comm. 7, 10641 (2016).
3. Denisov, D. V., Dang, M. T., Struth, B., Zaccone, A., Wegdam, G. H., and Schall, P., Sharp symmetry-
change marks the mechanical failure transition of glasses, Sci. Rep. 5, 14359 (2015).
4. Dang, M. T., Denisov, D., Struth, B., Zaccone, A., and Schall, P., Reversibility and hysteresis of the sharp
yielding transition of a colloidal glass under oscillatory shear, Eur. Phys. J. E 39, 44 (2016).
5. Jaiswal, P. K., Procaccia, I., Rainone, C., and Singh, M., Mechanical yield in amorphous solids: a first-order
phase transition, Phys. Rev. Lett. 116, 085501 (2016).
6. Leishangthem, P., Parmar, A. D. S., and Sastry, S., Nat. Commun. 8, 14653 (2017).
7. Chikkadi, V., Miedema, D. M., Dang, M. T., Nienhuis, B., and Schall, P., Shear banding of colloidal glasses
- Observation of a dynamic first order transition, Phys. Rev. Lett. 113, 208301 (2014).
8. Benzi, R., Sbragaglia, M., Bernaschi, M., Succi, S., and Toschi, F., Cooperativity flows and shear-bandings:
a statistical field theory approach, Soft Matter. 12, 514, (2016).
Nonlin-Dyn-6 ORAL CONTRIBUTIONS
Invited Talk
Nonlinear response upon shearing: a potential energy
landscape perspective
Andreas Heuer, Lawrence Smith, Markus Blank-Burian
University Muenster, Institute for Physical Chemistry, D-49149 Muenster
The nonlinear response of glasses upon shearing displays some fascinating aspects. For
example, when applying oscillatory athermal quasi-static shear one observes a dynamical
transition between localization and diffusive behavior [1], when varying the amplitude of the
shear deformation. Furthermore, an interesting balance between aging and rejuvenation is
observed [2].
In the quiescent limit and for temperatures above the glass transition the dynamics of a
supercooled liquid can be described by hopping processes between metabasins in a time-
invariant potential energy landscape (PEL) [3]. However, for finite shear rates the PEL
changes with time which no longer allows one to use the versatile concept of metabasins in
the standard way. Furthermore, in the limit of small temperatures the nature of the dynamical
processes changes and dynamical processes require the vanishing of energy barriers in the
PEL.
To characterize all cases in one formalism we suggest a new minimization scheme of the
potential energy which allows us to define metabasins also for finite shear rates. The key idea
is to use also the deformation as a parameter to be varied during the minimization. The
generalized definition of metabasins allows us to rationalize many observations for sheared
system. For example, we can relate the occurrence of the stress overshoot to the presence of a
metabasin transition. Furthermore, in shear reversal simulations we can predict the height of
the reversal overshoot, based on information about metabasin transitions in the course of the
shear cycle.
REFERENCES
1. Fiocco, D., Foffi, G., Sastry, S., Phys. Rev. E 88, 020301 (R)(2013).
2. Lacks, D.J., and Osborne, M.J., Phys. Rev. Lett. 93, 255501 (2004).
3. Heuer, A., J. Phys.: Cond. Mat. 20, 373101 (2008).
ORAL CONTRIBUTIONS Nonlin-Dyn-7
Invited talk
High strain rate properties of polymer materials
J.W. Andzelm, T.W. Sirk, R.M. Elder, In-Chul Yeh, Y. Sliozberg, J.L.
Lenhart
The U.S. Army Research Laboratory, Aberdeen, MD, USA
At very high strain rates all polymers exhibit glassy-like behavior which is critically important in
designing protective polymer composites with optimum dynamic strengthening and stiffening
characteristics. In this presentation we will briefly show how the mechanism of tensile deformation
and the mechanical properties are affected by increasing strain rates for a polymer gel, thermoset
polymer network and also semicrystalline polymer.
In our first example [1] polymer gel is diluted with a solvent of various architecture, including a
branched solvent with rigid side chains (spikes). We find a significant dependence of the gel modulus
on the strain rate and architecture of the solvent. The spikes aggregate into clusters and form an
additional secondary network. As a result, the tensile stress and relaxation modulus are markedly
higher than the stress and modulus of conventional gels.
The high strain rates mechanical properties of cross-linked polymer systems have been studied in our
Laboratory for number of systems. [2,3] The glass transition temperature is of particular interest,
although it is not possible to directly calculate under the same conditions as experiments. We have
determined Young’s modulus as a function of temperature across strain rates and using the time-
temperature superposition (TTS) principle we developed a master curve that is in reasonable
agreement with experiental data. We will discuss the limitations of applying TTS to high strain rates in
simulations.
The lamellar stack model of semicrystalline polyethylene was used to elucidate mechanism of tensile
deformations as a function of strain rates, crystalline and noncrystalline layer thicknesses or chain
orientation in the crystalline region. [4] We have found that at the slower strain rates the
melting/recrystallization transitions were favored, while at the faster strain rates the cavity formation
in the noncrystalline domain was the dominant deformation mechanism.
REFERENCES
1. Sliozberg, Y., Chantawansri, T., Lenhart, J.L., Andzelm, J.W., ” Structural and mechanical properties of advanced
polymer gels with rigid side-chains using coarse-grained molecular dynamics”, Polymer. 55, 5255-5275 (2014)
2. Sirk, T.W., Khare, K.S., Karim, M., Lenhart, J. , Andzelm, J.W., McKenna, G.B., Khare, R., “high strain rate
mechanical properties of a cross-linked epoxy across the glass transition”, Polymer. 54, 7048-7057 (2013)
3. Elder, R.M., Knorr, D.B., Andzelm, J.W., Lenhart, J.L., Sirk, T.W., “Nanovoid formation and mechanics: a comparison
of poly(dicyclopentadiene) and epoxy networks from molecular dynamics simulations”, Soft Matter. 12, 4418-4434
(2016)
4. Yeh, I. C., Lenhart, J.L., Rutledge, G., Andzelm, J.W., “Molecular Dynamics Simulations of the Effects of Layer
Thickness and Chain Tilt on Tensile Deformation Mechanisms of Semicrystalline Polyethylene”, Macromolecules.
50,1700-1712 (2017)
Nonlin-Dyn-8 ORAL CONTRIBUTIONS
Invited Talk
Relaxation of Comb and Bottlebrush Polymers under
SAOS, LAOS and Extensional Flows
Mahdi Abbasi, Manfred Wilhelm
Institute of Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology
(KIT), Engesserstraße 18, 76131 Karlsruhe, Germany
Linear and nonlinear rheological properties of branched polymer melts are of special interest
to academia and industry due to both the strain hardening and the dynamic dilution effects of
the branches. Small amplitude oscillatory shear (SAOS) is a very sensitive method to
characterize the branched topologies in polymers. However large amplitude oscillatory shear
(LAOS) as well as extensional deformations not only can be used to distinguish the presence
of branched structures but also are useful to study the nonlinear phenomena in polymer
processing. Here, SAOS, LAOS and extensional deformations will be used to distinguish
between comb and bottlebrush conformations in polymer melts. Several different comb shape
polystyrenes with similar backbone, Mw,bb = 290 kg/mol, and branch length, Mw,br = 44
kg/mol, but different number of branches, 3 < Nbr < 190, have been synthesized using anionic
polymerization, so that these polymers cover loosely to densely comb and loosely bottlebrush
conformations. We investigated scaling laws for zero shear viscosity and diluted modulus in
SAOS[1], the strain hardening factor in extensional flows[2] and an intrinsic nonlinearity in
LAOS[3, 4], in order to distinguish between comb and bottlebrush topologies.
REFERENCES
1. Bahreini, E., et al., Influence of molecular structure on the foamability of polypropylene: Linear and
extensional rheological fingerprint, Journal of Cellular Plastics. 0(0): p. 0021955X17700097.
2. Abbasi, M., N. Golshan Ebrahimi, and M. Wilhelm, Investigation of the rheological behavior of industrial
tubular and autoclave LDPEs under SAOS, LAOS, transient shear, and elongational flows compared with
predictions from the MSF theory, Journal of Rheology. 57(6): p. 1693-1714 (2013).
3. Kempf, M., et al., Synthesis and Linear and Nonlinear Melt Rheology of Well-Defined Comb Architectures
of PS and PpMS with a Low and Controlled Degree of Long-Chain Branching, Macromolecules. 46(12): p.
4978-4994 (2013).
4. Kyu Hyun, M.W., Christopher O. Klein, Kwang Soo Cho, Jung Gun Nam, Kyung Hyun Ahn, Seung Jong
Lee, Randy H. Ewoldt, Gareth H. McKinley, A review of nonlinear oscillatory shear tests: Analysis and
application of large amplitude oscillatory shear (LAOS), Progress in Polymer Science. 36(12): p. 1697-1753
(2011).
ORAL CONTRIBUTIONS Nonlin-Dyn-9
Invited Talk
Molecular Dynamics Simulation On The Avalanche
Dynamics and the microstructural evolution in the so called
elastic region of the glassy CuZr system.
Alexandra E. Lagogianni, Marius Milnikel, and Konrad Samwer
I. Physikalisches Institut, Georg- August Universität Göttingen,Göttingen,Germany
We present results on the study of the avalanche dynamics of a 3D Cu50Zr50 system by means
of molecular dynamics simulations. The system is subjected to a finite strain rate deformation
scheme and to the athermal quasistatic protocol. We find that the avalanches occur from the
beginning of the so called elastic region. The critical exponents obtained by the stress drop
sizes and time duration distributions for the elastic and plastic region are similar, indicating
that the difference in the deformation mechanisms that govern the two regions are not
depicted in these kind of statistical profiles of the avalanche dynamics. The two regions differ
in the way that the number of the avalanches, their average size and the instantaneous shear
modulus evolves with strain. Additionally the stress drops are accompanied by the appearance
of regions in the systems that undergo shear transformations and consist of characteristic
categories of clusters. The percentage of the most frequent types of clusters in these regions
evolves with strain in a correlated manner with the total stress and energy of the system. The
overall decrease/increase of the number of clusters upon deformation is taking place by a
continuous structural loop where an initial type of cluster transforms into an intermediate one
with the same coordination number and consecutively the intermediate type of cluster
transforms back again to the initial one.
REFERENCES
1. Liu, C., Ferrero, E. E. , Puosi, F. , Barrat, J. L., Martens, K., Phys. Rev. Lett.116, 065501 (2016).
2. Dubey, A. K., Procaccia, I., Shor, C. A., and Singh, M., Phys. Rev. Lett. 116, 085502, (2016).
3. Krisponeit, J. O, Pitikaris, S., Avila, K. E., Küchemann, S., Samwer, K., Nat. Commun. 5, 3616 (2014).
4. Antonaglia, J., Wright, W. J., Gu, X., Byer, R. R, Hufnagel, T. C, LeBlanc, M., Uhl, J.T, Dahmen K.A,
Phys.Rev.Lett. 112,155501 (2014).
Nonlin-Dyn-10 ORAL CONTRIBUTIONS
Invited Talk
Molecular dynamics simulations of dynamical mechanical
spectroscopy in metallic glasses: linear and nonlinear
responses
HaiBin Yu
Wuhan National High Magnetic Field Center, Huazhong University of Science and
Technology, China
Relaxation dynamics are the central topics in glassy physics. They are usually measured by
the experimental techniques of dynamical spectroscopies such as the dielectric and
mechanical spectra. Here, we put the protocols of the dynamical mechanical spectroscopy into
molecular dynamics simulations. It reproduces the salient features of relaxation spectra as
measured experimentally. Moreover, combining it with detailed studies atomic movements
and structural analysis, we clarified the mechanisms of internal friction of metallic glasses [1].
We observed the strain driven glass transition and a pronounced fragility transition as induced
by nonlinear strain [2]. We find that the primary (α) relaxation always takes place when the
most probable atomic displacement reaches a critical fraction (∼20%) of the average
interatomic distance, irrespective of whether the relaxation is induced by temperature (linear
response) or by mechanical strain (nonlinear response) [3].
REFERENCES
1. Yu, H.-B, and Samwer, K., Phys. Rev. B 90, 144201 (2014).
2. Yu, H.-B., Richert, R., Maaß, R., and Samwer, K., Nat. Commun. 6, 7179 (2015).
3. Yu, H. B., Richert, R., Maaß, R., and Samwer, K., Phys. Rev. Lett. 115, 135701 (2015).
ORAL CONTRIBUTIONS Nonlin-Dyn-11
Invited Talk
Temperature modulation spectroscopy and the relaxation of
the free energy landscape
T. Odagaki1, T. Ishida
2 and Y. Saruyama
3
1 Research Institute for Science Education, Inc., Kyoto 604-8346. Japan
2 Tokyo Denki University, Saitama 350-0394, Japan
3 Kyoto Institute of Technology, Kyoto 606-8585, Japan
The free energy landscape (FEL) description of non-equilibrium systems is a robust approach
to unified explanation of dynamic and thermodynamic properties of super-cooled liquids. The
FEL depends on the temperature by its definition and thus one can obtain information on the
FEL from the responses of the system to temperature modulation. When the temperature is
modulated, the FEL is reorganized with time delay which is modelled as a relaxation process
with a relaxation time. We investigate how the relaxation of the FEL manifests itself in
physical properties.
Exploiting a simple two-level model for the dielectric relaxation, we first show that the
relaxation of the FEL produces a relaxation of the relaxation time for the dielectric relaxation.
Then we discuss the relaxation of dielectric susceptibility when the temperature is suddenly
increased/decreased1 and show that the susceptibility relaxes to the equilibrium value with the
same relaxation time as the FEL in the long time limit. We also investigate effects of a
sinusoidal temperature modulation which can be observed in the second-order non-linear
susceptibility.2 We employ a model glass forming system and show that the non-linear
susceptibility shows significant dependence on the relaxation time of the FEL when the
temperature is below the crossover temperature.
REFERENCES
1. Hecksher, T., Olsen, N. B., Niss, K., Dyre, J. C., “Physical aging of molecular glasses studied by a device
allowing for rapid thermal equilibration”, J. Chem. Phys. 133, 174514-1-14 (2010).
2. Harada, A., Oikawa, T., Yao, H., Fukao, K., Saruyama, Y., “A Kinetic Study on the Response of the
Relaxation Time of the α Process to Quick Temperature Change around the Glass Transition”, J. Phys. Soc.
Jpn. 81, 065001-1-2 (2012).
Nonlin-Dyn-12 ORAL CONTRIBUTIONS
Invited Talk
A kinetic study on the change in the relaxation time of the
alpha process induced by temperature modulation
Y. Saruyama*, M. Urushidani, H. Oku, S. Tatsumi and H. Yao
Kyoto Institute of Technology, Kyoto 606-8585, Japan
Delay of the response to the stimulus in the process, such as the dielectric polarization to
the electric field, the strain to the stress and so on, has been extensively studied around Tg. In
this work the authors paid attention to the response of the relaxation time of the process ()
to the temperature change. changes notably with temperature around Tg. It is natural to
consider that the change in after a temperature jump takes some time, that is, it delays.
An experimental technique, temperature modulated dielectric measurement (TMDM), has
been developed in the authors’ laboratory.1 In TMDM the sample temperature was modulated
at a given frequency (fT). Since the capacitance of the sample capacitor changed
synchronizing with the temperature modulation, TMDM signal contained non-linear
components which gave the information about the delay of . The delay time of were
calculated from fT dependence of the non-linear components at various temperatures. The
delay time of () was successfully measured with TMDM. It was found that temperature
dependence of was notably different from that of .
REFERENCE
1. Harada, A., Oikawa, T., Yao, H., Fukao, K., Saruyama, Y., “A Kinetic Study on the Response of the
Relaxation Time of the α Process to Quick Temperature Change around the Glass Transition”, J. Phys.
Soc. Jpn. 81, 065001-1-2 (2012).
ORAL CONTRIBUTIONS Nonlin-Dyn-13
Oral
From glass to supercooled liquid: long-range correlation of
shear strain persists
M. Hassani, F. Varnik
Interdiciplinary center for advanced material simulations (ICAMS), Ruhr Universität,
Bochum, Germany
While the elasticity in glassy materials is shown to be responsible to mediate long-range strain
correlations, there are evidences of similar long-range correlations in the supercooled state as
well [1], though low frequency shear modulus vanishes for this state. Via molecular dynamics
simulations of a 3D binary Lennard-Jones glass former, we study the temporal evolution of
these correlations in supercooled and glassy states [2]. Beside the quadropolar symmetry, the
supercooled liquid shares with the glass also the 1
𝑟3 power-law decay of strain correlations.
Interestingly, the evolution of strain amplitude follows a similar pattern as the single-particle
mean-square displacement; in the glass, the amplitude comes to arrest in long time intervals,
whereas it follows a diffusive growth in the supercooled state. These findings are in
quantitative agreement with the mode-coupling theory predictions which suggest that high
viscosity in supercooled state facilitates long-range correlations [3].
REFERENCES
1. Chattoraj, J., Lemaitre, A., Elastic Signature of Flow Events in Supercooled Liquids Under Shear,
Phys. Rev. Lett.,111 (2013)
2. Hassani, M., Varnik, F., Survey of spatio-temporal strain correlations across the glass transition, (in
preparation)
3. Illing, B., Fritschi, S., Hajnal, D., Klix, C., Keim, P., Fuchs, M., Strain Pattern in Supercooled
Liquids, Phys. Rev. Lett. 117, 208002, (2016)
Nonlin-Dyn-14 ORAL CONTRIBUTIONS
Oral
Effects of polar and ionic interactions on cavitation in
glassy polymers
Shahsavari Ashkan, Caroll Vergelati, Didier Long
CNRS-Solvay, LPMA UMR 5268 CNRS-Solvay, 87 rue des frères Perret, 69192 Saint-Fons,
France
We have studied cavitation mechanisms in polymers by using molecular dynamics
simulations (MD) [refs. 1 and 2]. Characterizing the initiation of cavitation is of major
importance for the estimate of fracture properties under impact conditions. In the case of non-
polar polymers, Estevez and Long have shown that at a small scale, cavitation results from a
transition between a homogeneous to a highly heterogeneous deformation field during
loading. We proposed here two models for studding the effect of strong intermolecular
interactions on onset of cavitation: an isotropic model which represents ionic systems and a
directional model to describe hydrogen bonds. For both models, we have investigated the
effects of polar groups along the chain on these ultimate properties as a function of their
strength and density along the bag bond. At low fraction of polar groups (e.g. smaller than
10%) the effect is negligible and cavitation takes place at around 10% deformations. Upon
increasing the fraction of polar groups, we show that the onset of cavitation shifts to higher
deformations. This critical deformation amplitude goes through a maximum (around 40%
deformation amplitude) at a fraction of polar groups along the chain between 10 and 15%.
Beyond this value, the critical deformation decreases down to 15-20%, i.e. the sample
becomes more brittle. Our interpretation is that this behavior is related to the disorder of the
material [Ref. 3]. At a higher fraction, the sample becomes more homogeneous and more
brittle. The resuls in the case of ionic interaction can be mapped on those obtained with polar
polymers. Our model paves the way for devising polymers with enhanced ultimate properties.
REFERENCES
1. Estevez, R., and Long, D., Modelling Simul. Mater. Sci. Eng., 19, 45004 (2011).
2. Hoy, R. S., and Robbins, M. O., J. Polym. Sci., 44, 3427 (2006).
3. Fusco, C., Vanel, L., and Long, D. R., Eur. Phys. J. E, 36, 34 (2013).
ORAL CONTRIBUTIONS Polym-Dyn-1
Invited Talk
Why Many Polymers are so Fragile: The Final Answer?
Alexei Sokolov1, Vladimir Novikov
1 and Christiane Alba-Simionesco
2
1University of Tennessee and Oak Ridge National Laboratory, Knoxville, TN 37996, USA
2Laboratoire Léon Brillouin, UMR 12, CEA-CNRS, 91191 Saclay, France
E-mail: [email protected]
If fragility of molecular liquids is usually limited to m~80-100, many polymers exhibit
fragility m~150 and even higher. The mechanism of this unusually steep temperature
dependence of structural relaxation (high fragility) in polymers still remains a puzzle [1]. To
reveal additional hints for understanding the underlying mechanism, we analyzed molecular
weight (MW) dependence of chain and segmental dynamics in several polymers. While
fragility of segmental dynamics in many polymers increases sharply with MW, fragility of
chain dynamics appears to be essentially independent of MW and comparable to fragility of
small molecular liquids. Our surprising discovery is that the temperature dependence of the
chain relaxation in polystyrene follows well the Adam-Gibbs relationship, which fails in the
case of segmental relaxation [2]. Moreover, many correlations that fail for segmental
dynamics fragility work well for chain fragility [2]. These results suggest that the molecular
level relaxation (chain relaxsation) still follows the behavior usual for small molecules even
in polymers. It is the segmental relaxation that has the unusually high fragility. We suggest
that many polymers cannot reach an ergodic state on the time scale of segmental dynamics
due to chain connectivity and rigidity. This leads to a sharper decrease in accessible
configurational entropy upon cooling, and results in steeper temperature dependence of
segmental relaxation. The proposed scenario provides a new important insight in specifics of
polymer dynamics: the role of ergodicity time and length scale. At the end we suggest that
similar scenario can be applicable also to other molecular systems with slow intra-molecular
degrees of freedom, and to chemically complex systems where time scale of chemical
fluctuations can be longer than the time scale of structural relaxation.
REFERENCES
1. Sokolov, A.P., Novikov, V.N., Ding, Y., J.Phys.Cond.Matt. 19, 205116 (2007).
2. Dalle-Ferrier, C. et al., J. Chem. Phys. 145, 154901/1-10 (2016).
Polym-Dyn-2 ORAL CONTRIBUTIONS
Invited Talk
Influence Of Chain Length On Relaxation And Fragility: A
Study From Oligomers To Polymers Of
Poly(Methylmethacrylate)
Laura Andreozzi, Marco Giordano, Fabio Zulli
Department of Physics “ E. Fermi” , University of Pisa and IPCF-CNR, 56127 Pisa, Italy
A combined study of local relaxation and dynamic fragility is presented in a series of poly
methylmethacrylates (PMMA) of varying molecular weight from oligomers to polymers.
Rotational relaxation properties are measured using ESR spectroscopy; viscosity, fragility and
thermal parameters are obtained by shear rheology measurements.
Significant variations of fragility with molecular weight are observed, with a decreasing trend
from low masses to polymers that reaches a plateau for high polymers. The results also
suggest a positive correlation between kinetic fragility and the change ΔCp (Tg) with mass.
Changes in the rotational relaxation properties (dynamic crossovers) are observed as a
function of temperature at TC. A step-like behavior appears in the dependence of crossover
temperatures on the the masses, separating oligomers and unentangled PMMA polymers.
Decoupling phenomena and violations of the Debye Stokes Einstein relation characterize the
rotational dynamics of the PMMA series, evidencing that chain length exerts a strong
influence on local segmental relaxation properties. Different dynamics regimes and coupling
degrees of the local relaxation to the viscous flow will be discussed in the present work as
well as step-like features with mass. The latter is a recurrent result and discriminate in the
rotational relaxation and in its dynamic parameters the typical molecular-like behavior
followed by the oligomers from a more specific polymeric response. Particular attention has
been devoted to the onset of the Rouse dynamics and to the polymer regime of PMMAs. The
scaling law of the relaxation times with the mass are considered in the different temperature
regions, above and below the dynamic crossover at TC. It is found that in the high temperature
region the results are in agreement with the forecasts of the Rouse theory. Below TC, the
scaling law exponent can be accounted for by resorting to the Guenza theory of the
cooperative intra-chain dynamics of polymers (1).
REFERENCES
1. Guenza, M.G., Phys. Rev. Lett. (2002) 88, 025901.
ORAL CONTRIBUTIONS Polym-Dyn-3
Invited Talk
Chain-length dependent relaxation dynamics in glass-
forming oligomers and polymers
D. Baker1, M. Reynolds
1, R. Masurel
2, P.D. Olmsted
2, J. Mattsson
1
1School of Physics and Astronomy, University of Leeds, Leeds, U.K.
2Department of Physics, Georgetown University, Washington D.C. USA
We here discuss new experimental and computational results focusing on the effect of
molecular size and chain-connectivity on the relaxation behaviour in glass-forming oligomers
and polymers. We show experimental results from broadband dielectric spectroscopy,
calorimetry and oscillatory rheology together with results from computer simulations. We
discuss the detailed development of molecular relaxation dynamics (structural relaxation and
secondary relaxations) as well as chain conformations and overall chain size with chain-
length for oligomeric and polymeric systems of different chain characteristics. We
particularly focus on the role of secondary relaxations in glass-formations and show results on
the nature and inter-relationship of secondary relaxations for oligomeric and polymeric
systems and discuss their link to the structural relaxation and thus the glass transition
temperature. Moreover, we discuss the link between glass-formation in small molecular and
oligomeric/polymeric glass-formers and discuss our results in the light of models/theories that
can be used to understand the observed behaviour.
Polym-Dyn-4 ORAL CONTRIBUTIONS
Oral
Tuning the Dynamic Fragility of Acrylic Polymers by Small
Molecules: the Interplay of Hydrogen Bonding Strength
Guozhang Wu*, Chongyang Liu
School of Materials Science & Engineering, East China University of Science & Technology,
130 Meilong Rd., Shanghai 200237, China
High Tg polymers exhibit high fragilities in general.1 Here, we report for the first time that
small molecules with double phenolic end groups are effective to independently mediate the
dynamic fragility (m) and glass transition temperature (Tg) of acrylic polymers. Broad band
dielectric spectrometer (BDS), Fourier transform infrared spectroscopy (FTIR), and
Differential scanning calorimeter (DSC) measurements showed that the addition of small
molecules with a concentration lower than 30 wt.% leads to a narrower relaxation time
distribution of the intermolecular cooperative rearrangement motion because of the formation
of hydrogen bonding networks. These acrylic polymers exhibited a significant decrease in m
while showing a linear increase in Tg by changing the loading of the small molecules. Further
experimental results demonstrated that m decreases monotonically with intermolecular
hydrogen bonding strength for a given host polymer matrix. The m/ Tg value diminishes with
increasing small molecule content, whereas the value remains slightly changed by the
copolymerization of different amounts of styrene on the acrylate chains. These results
demonstrate that the compelling opposite change in m and Tg in the small molecule-loaded
system is dominated by enthalpic intermolecular interactions. A distinct reduction of m in
relation with small molecules was observed in poly(butyl methacrylate), where a methyl
group attached to the same C atom of the hydrogen bonding ester group. The impact
difference of size, number, and steric hindrance of phenolic groups in small molecules, as
well as the chemical structure of polymers, on the mixture’s fragility and Tg was discussed
based on the generalized entropy theory of glass formation.2
REFERENCES
1. Betancourt, B., Douglas, J., Starr, F., Fragility and Cooperative Motion in Glass-formed Polymer-
nanoparticle Composite, Soft Matter. 9, 241-254(2013).
2. Kunal, K., Sokolov A., Robertson C., Pawlus S., Hahn S., Role of Chemical Structure in Fragility of
Polymers-A Qualitative Picture. Macromolecules. 41, 7232-7238(2008).
3. Agapov, A., Wang, Y., Kunal, K., Robertson, C., Sokolov, A., Effect of Polar Interactions on Polymer
Dynamics, Macromolecules. 45, 8430-8437(2012).
ORAL CONTRIBUTIONS Polym-Dyn-5
Invited Talk
From Single-Chain Nano-Particles to All-Polymer Nano-
Composites
A. Arbe, J. A. Pomposo, A. J. Moreno, J. Colmenero
Centro de Fisica de Materiales (CFM) (CSIC-UPV/EHU), Materials Physics Center (MPC),
Pº Manuel de Lardizabal 5, 20018 San Sebastián, Spain
Single-Chain Nano-Particles (SCNPs) obtained by intra-molecular cross-linking of linear
macromolecules (precursors) are emerging soft nano-objects showing unique and remarkable
physicochemical, rheological, and sensing properties as a result of their locally collapsed
structure and ultrasmall size. One of the first envisaged applications for SCNPs was to be
used as ‘fillers’ in all-polymer nano-composites. Here we present the results of our recent
investigations on the properties of SCNPs in solution and how they develop upon crowding
their environment, with the all-polymer nano-composite as limit. The small angle scattering
results obtained on real systems are interpreted in the light of coarse-grained molecular
dynamics simulations. Contrarily to the a priori assumed globular conformation, in solution
SCNPs adopt sparse morphologies [1]. Crowding induces compaction of the SCNPs reflected
in a decrease of the chain dimensions and the scaling exponent [2]. In the limit case of the
nano-composite, the observed conformation of the SCNP resembles that of a crumpled
globule [2]. Furthermore, the impact of the presence of SCNPs based on poly(methyl
methacrylate) (PMMA) on the dynamics of the polymer matrix (linear poly(ethylene oxide)
(PEO) chains) is investigated by quasielastic neutron scattering [3,4]. We observe a slowing
down of the Rouse-like PEO dynamics –due to the strong dynamic asymmetry of the
components— as well as a pronounced increase of the explored volume of the PEO chains
(disentanglement). A comparative study of the analogous blend of linear chains demonstrates
that this effect must be attributed to the particular topology of the PMMA SCNPs.
REFERENCES
1. Pomposo, J.A. et al, How Far Are Single-Chain Polymer Nanoparticles in Solution fron the Globular
State?, ACS Macro Lett. 3, 767-772 (2014).
2. Moreno, A.J. et al, Concentrated Solutions of Single-Chain Nanoparticles: A Simple Model for Intrinsically
Disordered Proteins under Crowding Conditions, J. Phys. Chem. Lett. 7, 838-844 (2016).
3. Bhowmik, D. et al, Microscopic Dynamics in Nanocomposites of Poly(ethylene oxide) and Poly(methyl
methacrylate) Soft Nanoparticles: A Quasi-Elastic Neutron Scattering Study, Macromolecules. 47, 304-315
(2014).
4. Arbe, A. et al, Single Chain Dynamic Structure Factor of Linear Polymers in an All-Polymer Nano-
Composite, Macromolecules. 49, 2354-2364 (2016).
Polym-Dyn-6 ORAL CONTRIBUTIONS
Invited Talk
Microscopic dynamics in molecular gels.
M. Plazanet1, M. Gonzalez
2, S. Spagnoli
1 and I. Morfin
1
1Laboratoire Interdisciplinaire de Physique, Univ. Grenoble-Alpes & CNRS, Grenoble, France
2Institut Laue Langevin, Grenoble, France
Physicals gels formed by low molecular weight organic gelators (LMMOG) are composed of
a rigid network formed by the gelators, in which is trapped a large quantity of solvent.
Gathering properties of both liquids and solids, they find applications as functionalised
nanomaterials in diverse domains, although applications suffer several limitations, mainly the
unexpected collapse after some time and to the difficulty to predict gelation ability of new
molecules. The subtle interplay of the different forces exerted between the solvent and
gelators enable the gels to reversibly assemble in a restricted temperature range in a complex
structure that depends on the solvent. Because of the instrinsic complexity, at the molecular
level, of the structural organisation and the dynamics, these materials are quantitatively
studied with difficulty. In this context, we undertook the study of the microscopic dynamics in
a model physical molecular gel, methyl-4,6-O-benzylidene-α-D-mannopyranoside (α-manno)
[1] in water and toluene are probed by neutron scattering [2] and Transient Grating
Spectroscopy [3]. The α-manno is an amphiphilic gelator that adopts different organisation in
both solvents. We were able to determine, on a timescale from a few ps to few ns, the fraction
of each dynamical population of solvent molecules in interaction with the rigid network
formed by the gelators. We found that only few toluene molecules per gelator participate to
the network which is formed by hydrogen bonding between the gelators’ sugar moieties. In
water, however, the interactions leading to the solid network assembly are weaker and
hydrogen bonds are formed with 10 to 14 surrounding water molecules per gelator. This study
shows that quantitative information can be obtained about the behaviour of solvent confined
in a molecular gel, also relevant to diffuse interfaces as often encountered in soft matter
systems.
REFERENCES
1. GRONWALD O, SHINKAI S, Sugar-Integrated Gelators of Organic Solvents, Chem. Eur. J. 7, 4328-4334
(2001).
2. SPAGNOLI S., MORFIN I., GONZALEZ M.A., CARCABAL P., PLAZANET M., Solvent contribution to
the stability of a physical gel characterised by quasi-elastic neutron scattering, Langmuir 31, 2554−2560
(2015).
3. MORFIN I., SPAGNOLI, S., RAMBAUD C., LONGEVILLE S., PLAZANET M., Behaviour of a solvent
trapped in a physical molecular gel, Phil. Mag., 809-815 (2016).
ORAL CONTRIBUTIONS Polym-Dyn-7
Invited Talk
Segment-Scale, Force-Based Theory of Mesoscopic Dynamic
Localization and Emergent Elasticity in Entangled Chain
Polymer Liquids
Zachary E. Dell, Kenneth S. Schweizer
University of Illinois at Urbana-Champaign, USA
Chain entanglements in dense solutions and melts of high molecular weight polymers result in
complex dynamic and viscoelastic behavior. The state-of-the-art models are
phenomenological and based on the Edwards “tube” picture, in which isotropic Rouse motion
breaks down beyond a mesoscopic length scale and chains become confined perpendicular to
their backbone. While tube-based models are widely accepted and applied, understanding the
microscopic origins of the confinement remains an open problem. We have developed a
force-level, segment-scale, generalized Langevin equation theory formulated in terms of N
coupled dynamic order parameters [1]. Breakdown of the Rouse model and the emergence of
isotropic mesoscopic localization is predicted in the absence of ergodicity-restoring
anisotropic reptation or activated hopping. The theory is implemented using a universal
Gaussian thread model of polymer structure. The physical idea is that the isotropic Rouse
model fails due to the emergence of time-persistent intermolecular contacts, which are
determined by the combined influence of local uncrossability, long range polymer
connectivity, and a self-consistent treatment of chain motion and the dynamic forces that
hinder it. For long chain melts, the mesoscopic localization length (tube diameter) and
entropic elasticity predictions are in near quantitative agreement with experiment. The onset
chain length scales with the semi-dilute crossover concentration with a realistic numerical
prefactor. As chain crossing is allowed in two manners, the tube diameter swells until it
reaches the radius-of-gyration at which point mesoscopic localization vanishes. A dynamic
phase diagram for such a delocalization transition is constructed, which is qualitatively
consistent with simulations and the classic concept of a critical entanglement degree of
polymerization. This work provides a foundation to study other dynamics problems where
connectivity and intermolecular forces are crucial, such as physical gels, charged polymer
solutions, and ring polymers melts.
REFERENCES
1. Dell, Z.E., Schweizer, K.S., Segment-scale, force-level theory of mesoscopic dynamic localization and
entropic elasticity in entangled chain polymer liquids, J. Chem. Phys. 146, 134901 (2017).
Polym-Dyn-8 ORAL CONTRIBUTIONS
Invited Talk
Tuning polymer dynamics by chain-end association
Martin Tress1, Kunyue Xing
1, Pengfei Cao
2, Shiwang Cheng
2, Tomonori
Saito2, Vladimir Novikov
1, and Alexi Sokolov
1,2
1University of Tennessee Knoxville, Department of Chemistry, 1420 Circle Dr., Knoxville,
37916, Tennessee, USA
2Oak Ridge National Lab, Chemical Sciences Division, 1 Bethel Valley Rd, Oak Ridge,
37830, Tennessee, USA
Functional end groups in polymers are a molecular tool to reversibly connect and disconnect
chains to combine properties of both short polymer and large supramolecular structures. The
topology of the latter – and in turn the respective properties – can be tuned by the choice of
the functional group. This is shown in a series of polydimethyl siloxanes (PDMS) of different
molecular weight (MW) which are terminated by amino and carboxylic (-COOH) groups,
respectively. Differential scanning calorimetry and dielectric spectroscopy measurements
reveal that segmental dynamics are identical for the chains with two different end groups. In
contrast, rheology unravels a mechanical reinforcement for PDMS-COOH and a rise in
viscosity by ~2 decades. This is accompanied by a 2nd Tg and a corresponding dielectric
relaxation process which indicates phase separation of the end groups in clusters forming a
physically crosslinked network. As a consequence, the viscoelastic properties can be tuned
from common short polymer chains at high temperatures to highly entangled or even
crosslinked systems at T close and below the 2nd Tg. This suggests a promising route to
combine easy processibility of low MW polymers with the desired mechanical performance
of high MW polymers or even crosslinked networks.
ORAL CONTRIBUTIONS Polym-Dyn-9
Oral
Dynamic and structural investigation of interactions at the
origin of the plasticization of a polymer matrix: the case of
DMP-plasticized Cellulose Acetate
E. Dudognona, A. Benazzouz
b, V. Molinier
b, J-M. Aubry
b, M. Descamps
a,
N.T. Correiaa
University of Lille Nord de France, Bât. P5, 59655 Villeneuve d'Ascq Cedex, France
a UMET, UMR CNRS 8207,
b ENSCL, UCCS, UMR CNRS 8181
Processing of polymeric materials requires heating at a temperature high enough to obtain a
sufficiently low viscosity, which is not possible for polymers that encounter thermal
degradation. To get round this difficulty, plasticizers are usually incorporated into the
polymer matrix. It is the case of semi-crystalline biopolymers as Cellulose and its derivatives
that have a very high melting temperature close to the thermal decomposition. For Cellulose
Acetate, common plasticizers are phthalates but extensive research is devoted to finding
alternatives plasticizers with less harmful effects on environment and health, which requires
the understanding of the plasticization mechanisms, i.e. the understanding of the nature of
interactions that develop between the additive and the polymer matrix.
Here, we present the results of an investigation of the plasticizing effect resulting from the
incorporation of Dimethyl Phthalate (DMP) in Cellulose Acetate (CA), by means of two types
of spectroscopies allowing us to probe structural and dynamic features: Infrared spectroscopy
and Dielectric Relaxation spectroscopy [1]. The complementarity of these two techniques
allows us to establish that no strong H-bonding type interactions develop between DMP and
CA but, instead, that the plasticization effect is due to the development of weaker interactions
of dipolar type between the acetyl side group of CA and the ester phthalate moieties of DMP.
These interactions increase the overall mobility of CA chains (visible, especially, through the
evolution of the βJG Johari-Goldstein relaxation that turns out to be an interesting probe of the
plasticizing effect), but also reduce the water uptake tendency of CA, which leads to smaller
effects of water on the local dynamic.
REFERENCES
1. Benazzouz, A., Dudognon, E., Correia, N.T., Molinier, V., Aubry, J-M., Descamps, M., Interactions
underpinning the plasticization of a polymer matrix: a dynamic and structural analysis of DMP-
plasticized cellulose acetate, Cellulose. 24, 487-503 (2017).
Polym-Dyn-10 ORAL CONTRIBUTIONS
Oral
Polymer dynamics under cylindrical confinement: a locally
repulsive surface
M. Kruteva, S. Pasini, M. Monkenbusch, D. Richter
Jülich Centre for Neutron Science (JCNS-1), Forschungszentrum Jülich, Germany
In functional polymeric nanomaterials the confinement by a solid surface can have crucial
effects on the structural and dynamical properties of the polymer. Both in nanocomposites -
nanoparticles homogenously dispersed in a polymeric matrix - as well as in polymer chains
that are confined in porous media, e.g. in long cylindrical nanopores, the number of possible
conformations of a polymer chain can be reduced due to the presence of a large amount of
solid surface [1].
Neutron spin-echo investigations [2, 3] have evidenced that the attractive polymer-surface
interaction can have a two-fold effect: The adsorption of polymer to the pore surface favors
the formation of a surface layer that slows down the dynamics [2] - as compared to the that of
pure polymer; the anchoring of the polymer segments on the surface creates an interphase
between the polymer in close vicinity to the solid surface and the pure polymer [3]. It was
also observed that under strong confinement conditions [4] the entanglement network
becomes diluted.
Here we will consider confinement in absence of specific adsorption of the polymer segment
on the Alumina surface, i.e. we will investigate locally repulsive polymer-surface interaction
for polyethylene-alt-propylene confined in cylindrical Alumina nanopores [5]. We show that
in the regime of segmental dynamics even though expected on the basis of simulations, no
effect of the confining walls on the local segment relaxation is observed. On the larger scale
both the Rouse relaxation rate and the entanglement distance do not differ between bulk and
confined polymer melts within experimental accuracy. The experiments clearly show that for
a confinement size equaling the polymer end-to-end distance, the entanglement network is not
affected, a result that is not so clear from simulations.
REFERENCES
1. Polymer Interfaces and Interphases, Soft Materials: Special Issue, 12 (2014)
2. Krutyeva, M. et al., J. Chem. Phys. 131, 174901 (2009)
3. Krutyeva, M. et al., Phys. Rev. Lett. 110, 108303 (2013)
4. Martin, J., Krutyeva, M. et al., Phys. Rev. Lett. 104, 197801 (2010)
5. Krutyeva, M. et al., J. Chem. Phys. 146, 203306 (2017)
ORAL CONTRIBUTIONS Polym-Dyn-11
Invited Talk
A force-level theory of the tube confinement field and the
rheology of entangled rod and chain polymer liquids
Daniel M. Sussman1 and Kenneth S. Schweizer
2
1 Department of Physics, Syracuse University, Syracuse, NY, USA 13244
2 Department of Material Science, University of Illinois, Urbana, IL, USA 61801
We employ a force-level approach to construct the transverse confinement field associated
with topological constraints in fluids of either entangled rigid rods or flexible chains
described at the primitive path level. A self-consistent treatment of this theory at the harmonic
level leads to a prediction for the tube diameter, which we use to analyze the change in the
degree of entanglement as a function of geometric confinement, chain stretching, and
spontaneous or mechanically induced orientation. We further propose an ansatz for extending
this theory to describe the strong anharmonic softening of transverse constraints, comparing
the resulting predictions with both experiments and simulation data for the distribution of
transverse polymer displacements. We then qualitatively discuss the implications of the
predicted anharmonic tube weakening and finite entanglement strength in the context of
simple constitutive models for the rheology of these systems.
REFERENCES
1. Sussman, D. M., and Schweizer, K. S., Phys. Rev. Lett. 107, 078102 (2011)
2. Sussman, D. M., and Schweizer, K. S., Phys. Rev. Lett. 109, 168306 (2012)
3. Sussman, D. M., et al., Macromol. 47, 6462-6472 (2014)
4. Schweizer, K. S., and Sussman, D. M., J. Chem. Phys. 145, 214903 (2016)
Polym-Dyn-12 ORAL CONTRIBUTIONS
Invited Talk
Dynamics of Polymer Melts and Blends from the
Unentangled to the Entangled Regime
Marina Guenza
Department of Chemistry, University of Oregon, Eugene OR, 97405
The Generalized Langevin Equation for the Cooperative Dynamics of polymer melts
describes with accuracy the dynamics of polymer liquids in both the unentangled and the
entangled regimes.(1) Intramolecular structure and flexibility, as well as intermolecular
interactions,(2) are explicitly accounted for in the formalism. Entanglements are included as
effective constraints to the chain dynamics. The dependence of the intra and intermolecular
potential on the thermodynamic parameters of the system effectively connects the dynamics
of the polymer melts and blends to their underlying phase diagram.
REFERENCES
1. Guenza, M. G., Localization of Chain Dynamics in Entangled Polymer Melts Phys, Rev. E 89, 052603-8
(2014).
2. Clark, A., McCarty, J., Lyubimov, I. Y., and Guenza, M. G., Thermodynamic consistency in variable-level
coarse-graining of polymeric liquids, Physical Review Letters. 109, 168301-5 (2012).
ORAL CONTRIBUTIONS Polym-Dyn-13
Invited talk
Heterogeneous Rouse Model Predicts Polymer Chain
Normal Mode Decoupling
David S. Simmons, Jui-Hsiang Hung
The University of Akron, 250 South Forge St., Akron OH, 44325. U.S.A.
It has been known for 50 years that polymers exhibit chain normal mode decoupling upon approach to
the glass transition1–3
, with chain dynamics exhibiting a weaker temperature dependence than
segmental dynamics. Inspired by the suggestion that this thermorheological complexity is a
consequence of dynamic heterogeneity in the supercooled state4, we generalize the Rouse model to
account for a distribution of segmental mobilities. The Heterogeneous Rouse Model (HRM) predicts
chain normal mode decoupling as a manifestation of diffusion/relaxation decoupling (Stokes-Einstein
breakdown) – a consequence of differences in how normal modes average over a distribution of
segmental relaxation times. Molecular dynamics simulations of an unentangled polymer melt are in
agreement with theoretical predictions, with the HRM found to quantitatively predict deviations from
Rouse scaling of the friction coefficient based on the degree of Stokes-Einstein breakdown. Consistent
with this model’s physics, lower chain modes are found to exhibit signatures of reduced dynamic
heterogeneity in terms of the non-Gaussian parameters and the stretching exponent of the self-
intermediate scattering function. Finally, the proposition that Stokes-Einstein breakdown and chain
normal mode decoupling are driven by dynamic heterogeneity has been challenged on the basis of
studies reporting a temperature-insensitive distribution of relaxation times as reported by broadband
dielectric spectroscopy (BDS) in liquids exhibiting pronounced diffusion/relaxation decoupling5. Here
we also probe the origin of this apparent discrepancy in terms of differences between signatures of
dynamic heterogeneity as probed by density-based and reorientational relaxation functions. This
comparison may also have implications for the interpretation of reorientational relaxation in thin
polymer films and for the comparison of simulated and experimental data.
REFERENCES
1. Plazek, D. J., Temperature Dependence of the Viscoelastic Behavior of Polystyrene, J. Phys. Chem. 69,
3480–3487 (1965).
2. Ngai, K. L., Plazek, D. J., Identification of Different Modes of Molecular Motion in Polymers That Cause
Thermorheological Complexity, Rubber Chem. Technol. 68, 376–434 (1995).
3. Ding, Y., Sokolov, A. P., Breakdown of Time−Temperature Superposition Principle and Universality of
Chain Dynamics in Polymers, Macromolecules. 39, 3322–3326 (2006).
4. Sokolov, A. P., Schweizer, K. S., Resolving the mystery of the chain friction mechanism in polymer liquids,
Phys. Rev. Lett. 102, 248301 (2009).
5. Ngai, K. L., Plazek, D. J., Roland, C. M., Comment on "Resolving the Mystery of the Chain Friction
Mechanism in Polymer Liquids", Phys. Rev. Lett. 103, 159801 (2009).
Polym-Dyn-14 ORAL CONTRIBUTIONS
Invited Talk
Polymer dynamics probed by field-cycling NMR
M. Hofmann, F. Mohamed, B. Kresse,+ A. Privalov,
+ N. Fatkullin,
*
F. Fujara,+ E.A. Rössler
University Bayreuth, +Technische Universität Darmstadt,
*University Kazan
Field-cycling (FC) NMR relaxometry has become an important tool investigating the dynamics in
complex fluids like polymers. By “cycling” the external magnetic field the frequency dependence of
the spin-lattice relaxation rate R1() is measured. Conventional relaxometers cover frequencies in the
range 10 kHz – 20 MHz (1H). Employing a self-built relaxometer with an earth field compensation,
frequencies down to 50 Hz are reached. Together with applying frequency-temperature superposition
more than ten decades in are covered. Polymer melts show in addition to segmental motion (s)
characteristic dynamics with terminal relaxation much longer than s. This leads to strong contribution
in R1() at s << 1. In the case of 1H, due to intra- as well as intermolecular origin of the relaxation,
R1() reflects rotational and translational dynamics along R1() = R1intra
() + R1inter
(). The sub-
diffusive translation is accessed by extracting R1inter
() via isotope dilution experiments. Hereby, the
segmental mean square displacement is revealed which is combined with that from field gradient
NMR. As predicted by the tube-reptation (TR) model, all four relaxation regimes of polymer dynamics
are identified,1 and comparison with results from neutron scattering becomes possible. Likewise,
information on reorientational dynamics is provided through R1intra
(). Regarding translation our
experiments confirm the TR model, yet the predictions concerning segmental reorientation are not
found. Specifically, the TR return-to-origin hypothesis connecting segmental rotation and translation
is not confirmed.2
Usually, polymer dynamics is accessed by monitoring the shear modulus G*(s). Thus, comparison
with results from FC NMR is of interest. This is done in the time domain after Fourier transforming
the measured data, i.e., stress relaxation function G(t/s) vs. NMR correlation function CNMR(t/s) (cf.
Fig.). While the macroscopic quantity G(t/s) is dominated by the rubber plateau, i.e., stress relaxes
only after complete renewal of the tube, the molecular function CNMR(t/s) reflects also relaxation with-
in the tube. In spite of such differences, there is strong correspondence in the glassy, Rouse and
terminal relaxation regime. Thus, FC NMR becomes a promising method of “molecular rheology”
characterizing molecular dynamics underlying macroscopic flow in complex fluids.
REFERENCES
1. Kresse et al. Macromolecules 48, 4491 (2015)
2. Hofmann et al. Macromolecules 49, 8622 (2016)
ORAL CONTRIBUTIONS Polym-Dyn-15
Invited Talk
Phase separation kinetics in unentangled polymer solutions
under extension
A.N.Semenov, A.V.Subbotin
Institut Charles Sadron, Strasbourg, France
A.V.Topchiev Institute of Petrochemical Synthesis, Moscow, Russia
It is well known that shear flow can affect the phase state of a polymer solution [1]. The
effects of elongational flows are much less understood even in the case of dilute solutions.
One of the important effects of uniaxial extension is the coil to stretched coil transition
predicted by De Gennes [2]. We show that this transition can generate a demixing instability
of a polymer solution in the dilute/semidilute concentration regime [3]. We develop a mean-
field theory for this flow-induced phase separation effect. We also study the kinetics of the
phase separation triggered by the coil elongation revealing a multi-stage process resulting in
formation of a polymer fiber with solvent released on its surface. [4] In particular, it is shown
that phase separation in dilute/semidilute polymer solutions can be induced by high-rate
extensional flow. The main driving force for the phase separation is a reduction of excluded-
volume repulsion due to flow-induced orientation of polymer segments. The polymer-solvent
demixing is a hierarchical process involving formation of protofibrils by anisotropic spinodal
decomposition, densification and thinning of the protofibrils, formation of a cross-linked
network of fibrils and its lateral collapse yielding a solidified oriented fiber.
REFERENCES
1. Larson, R.G., Rheol. Acta 31, 497 (1992).
2. de Gennes, P. G., J. Chem. Phys. 60, 5030 (1974).
3. Subbotin, A.V., Semenov, A. N., J.Polym.Sci.B 54, 1066 (2016).
4. Semenov, A. N., Subbotin, A.V., J.Polym.Sci.B 55, 623 (2017).
Polym-Dyn-16 ORAL CONTRIBUTIONS
Oral
Evolution of Entanglements during and after Startup Shear
Yuyuan Lu1, Yongjin Ruan
1, Lijia An
1, Shi-Qing Wang
2 and Zhen-Gang
Wang3
1State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied
Chemistry, Chinese Academy of Sciences, Changchun 130022, China
2Department of Polymer Science, University of Akron, Akron, OH 44325, United States
3Division of Chemistry and Chemical Engineering, California Institute of Technology,
Pasadena, CA 91125, United States
We develop a new primitive path analysis method to characterize entanglements in long-chain
polymer melts that is valid at both quiescent and large-deformation conditions. Using this
new method, we study the evolution of entanglements during and after startup shear for a
Kremer-Grest chain melt of length N=500. Our results reveal that: (1) shear considerably
inhibits the entanglement renewal rate relative to the convective constraint release (CCR)
mechanism at shear rates Wi > 1, and this effect increases with increasing shear rate; (2)
whereas CCR would predict nearly complete renewal of the initial entanglements by the point
of the stress overshoot, a significant fraction of the initial entanglements survive up to the
stress overshoot; (3) a significant fraction of the entanglements are formed by non-pairwise
multichain topological interactions; (4) upon cessation of fast startup shear, it takes up to 8
times the Rouse time for the chains to retract and for the dynamics of the entanglement
evolution to return to equilibrium. These findings offer possible mechanistic explanations for
the phenomenon of macroscopic flow after step shear, for the delay (with waiting time much
longer than the Rouse time) in the onset of the macroscopic flow, and for the longer than
expected overlap time in the reduced relaxation modulus [G(t, )/h()].
ORAL CONTRIBUTIONS Polym-Dyn-17
Invited Talk
Simulations of dynamical glass transition
in hard spheres and PS thin films
Scott T. Milner and Yuxing Zhou
Department of Chemical Engineering
Penn State University
We have used simulations of both hard-sphere fluids and polystyrene thin films to explore the
dynamical glass transition and reveal cooperativity in local dynamics.
Monodisperse hard spheres are perhaps the simplest glass-forming systems. Their strong
tendency to crystallize can be overcome by a “crystal-avoiding” hybrid Monte Carlo method,
which biases against the growth of crystalline order. Hard sphere systems are ideal for
analysis of how mobility disappears in glassy fluids. We present a purely geometrical
criterion that predicts the volume fraction of the dynamical glass transition, which also works
well when adapted to soft spheres. To reveal dynamical cooperativity in hard-sphere fluids,
we use arrays of “pinned” particles as a field to drive the glass transition. We infer the
cooperative length from the array spacing needed to drastically slow the system.
Glassy behavior in polystyrene thin films has been extensively studied experimentally. A free
surface “unpins” nearby segments and suppresses the glass transition. We use united-atom
MD, taking care to ensure consistent behavior between thin films and bulk. We obtain a film-
average Tg from density versus temperature (like ellipsometry experiments), and find Tg
shifts with thickness consistent with experiment. We also obtain consistent Tg shifts from
short-time dynamics (monomer displacements and bond rotations) versus temperature, which
for films of different thickness collapse to a master curve. Finally, we obtain *local* Tg
versus depth by applying the same approach to dynamics of segments at different depths,
which clearly reveals a mobile surface layer of about 4 nm.
Polym-Dyn-18 ORAL CONTRIBUTIONS
Invited Talk
A Finite Elements Model of the role of dynamical
heterogeneities on glassy polymer mechanics
H. Montes & F. Lequeux
Laboratoire Sciences et Ingénierie de la Matière Molle, PSL Research
University, UPMC Univ Paris 06, ESPCI Paris, CNRS, 10 rue Vauquelin,
75231 Paris cedex 05, France)
The mechanics of polymer in the glass transition domains reveals change of tremendous
change of dynamics with a few tens of Kelvin. At low temperature, the Eyring image
describes the polymers mechanics through elementary cage hops controlled by Van der Waals
interactions. Above the glass transition, the dynamics is controlled by the motion of chains
controlled by their entropy. In the glassy regime, dynamical heterogeneities make the glassy
polymer extremely heterogeneous at a mechanical point of view. Local elastic modulus varies
from domain to domain of 3 orders of magnitude, while relaxation time may vary of about 4
to 8 orders of magnitude. These gradients of properties must have a role in the mechanical
response in the glass transition regime. Consequently, we have recently developed – in
collaboration with Sabine Cantournet (Ecole des Mines, Evry, France), D.R. Long (LPMA,
Lyon, Francs) and A. Dequidt (Clermont Ferrand university, France) a finite elements
simulation of the mechanics of polymers in their glass transition regime. This numerical
model [1] describes quantitatively the shape of the alpha-relaxation peak in the viscoelastic
spectra, and also the confinement effects observed in filled elastomers [2]. We will discuss
this model and extend it to non-linear mechanical solicitations.
REFERENCES
1. Masurel, R., Cantournet, S., Dequidt, A., Long, D.R., Montes, H., Lequeux, F., Role of dynamical
heterogeneities on the viscoelastic spectrum of polymers: a stochastic continuum mechanics model
Macromolecules. 2015, 48 (18), pp 6690–6702
2. Masurel, R. J., Gelineau, P., Cantournet, S., et al. Role of Dynamical Heterogeneities on the Mechanical
Response of Confined Polymer, Phys. Rev. Lett. 2017, 118- 4 p047801
ORAL CONTRIBUTIONS Polym-Dyn-19
Oral
The Role of Functionality on Branch Point Motion of
Symmetric Star Polymers studied with MD Simulations and
NSE Spectroscopy
Stefan Holler*a, Angel Moreno
b,c, Michaela Zamponi
a, L. Willner
a,
P. Falusd, H. Iatrou
e, Dieter Richter
a
a Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
b Centro de Fisica de Materiales (CSIC-UPV/EHU) and MPC, 20018 San Sebastian, Spain
c Donostia International Physics Center, 20018 San Sebastian, Spain
d Institut Laue-Langevin, 38000 Grenoble, France
e Dep Chemistry, University of Athens, 15703 Athens, Greece
Large-scale molecular dynamics simulations and neutron spin echo (NSE) spectroscopy
experiments of center labeled star polymers with different number of arms (functionality) and
different arm length have been performed in order to directly observe the effect of
functionality on the mobility of the branch point (BP). Different scenarios can arise by
increasing the functionality, including early tube dilution through more "diving modes", or
tube-narrowing by increasing the topological constraints around the branch point. By varying
the arm length the influence of dynamic tube dilution (DTD) is investigated. Using a standard
bead spring model three-, four- and five-arm star polymers were simulated with a focus on the
branch point motion. NSE spectroscopy experiments with a labeling scheme unique to
neutron scattering allow us to directly observe the BP motion on a molecular scale by
measuring the dynamic structure factor S(Q,t). We investigated center labeled polyethylene
three and four-arm stars of different lengths in a pure melt. The change in mobility induced by
a change in functionality and different arm length manifests itself e.g in different time
dependencies of S(Q,t) in the longer time limit relating to an reduced mean square
displacement MSD of the BP for higher functionality and/or longer arms. By rescaling the
time dependence of the simulated S(Q,t) we can directly compare the simulations with our
experiments. We observed a decrease in mobility with higher functionality with both
techniques, which is suggesting dominant tube narrowing. This is also in accordance with our
BP trajectory analysis from our simulations. The influence of DTD can be described using a
model that considers the tube survival probability to describe the dilution of the branch point
confinement over time for the different arm lengths.
Polym-Dyn-20 ORAL CONTRIBUTIONS
Oral
Molecular Mobility of Super Glassy Polymers for Gas
Separation Membranes Investigated by Dielectric
Spectroscopy
Huajie Yin, Nora Konnertz, Martin Böhning, and Andreas Schönhals
Bundesanstalt für Materialforschung und –prüfung, Unter den Eichen 87, 12205 Berlin,
Germany
Super glassy polymers such as poly(trimethylsilylpropyne) (PTMSP) or polymers with
intrinsic microporosity (PIMs) play an important role in the current development of
membrane materials for gas separation because of their high permeability and selectivity.
Unfortunately, such materials which have a high fractional free volume (FFV) are prone to
pronounced physical aging. The initial microporous structures approach a more dense state
via local chain rearrangements which results in a dramatic reduction in the gas permeability.
For the first time, broadband dielectric spectroscopy was employed to investigate the
molecular dynamics of two representative groups of super glassy polymers: PIMs (PIM-1 &
PIM-EA-TB) (1-3) and Si-containing polynobornenes (PTCNSi1 & PTCNSi2) (4, 5). The
dielectric behavior of the solution-cast polymeric films was measured by isothermal
frequency scans during the different heating cycles in a broad temperature range. Structural
relaxation of the films was observed during the measurements. Molecular relaxation processes
following Arrhenius behavior with unusually high activation energies were observed for all
the investigated polymers. The PIMs showed furthermore a significant conductivity in the
glassy state which is explained with the formation of local intermolecular agglomerated
structures due to interaction of π-electrons in aromatic moieties of the polymer backbone.
REFERENCES
1. 1. Budd, P. M. et al., Polymers of Intrinsic Microporosity (PIMs): Robust, Solution-processable, Organic
Nanoporous Materials. Chem. Commun., 230-231 (2004).
2. 2. Konnertz, N. et al., Molecular Mobility of the High Performance Membrane Polymer PIM-1 as
Investigated by Dielectric Spectroscopy, ACS Macro Lett. 5, 528-532 (2016).
3. 3. Carta, M. et al., An Efficient Polymer Molecular Sieve for Membrane Gas Separations, Science. 339,
303-307 (2013).
4. 4. Gringolts, M. et al., New High Permeable Addition Poly(tricyclononenes) with Si(CH3)3 Side Groups.
Synthesis, Gas Permeation Parameters, and Free Volume, Macromolecules. 43, 7165-7172 (2010).
5. 5. Chapala, P. P.et al., A Novel, Highly Gas-Permeable Polymer Representing a New Class of Silicon-
Containing Polynorbornens As Efficient Membrane Materials, Macromolecules. 48, 8055-8061 (2015).
ORAL CONTRIBUTIONS Polym-Nanocom-1
Invited Talk
Interfacial interactions and complex segmental dynamics in
polymer nanocomposites: Dielectric and thermal studies
Apostolos Kyritsis*, Panagiotis Klonos, Polycarpos Pissis
Department of Physics, National Technical University of Athens, Zografou Campus, 15780,
Athens, Greece
Polymer nanocomposites (PNCs) are increasingly attracting interest in the scientific
community and the industry over the last 25 years, owing to significant improvement often
observed for several properties of the polymer matrix (thermal, mechanical, barrier) at much
lower filler factors as compared to conventional composites, as well as to new properties
(electrical, magnetic, optical) added by the filler. There is no theory yet to account for this
improvement of properties of PNCs, it is generally accepted, however, that interfacial effects,
defined as changes in structure/organization, dynamics and properties of the polymer at the
interface with the filler, play a significant role for that. Glass transition and segmental
dynamics of the polymer at the interface with the filler are expected to be modified with
respect to the bulk and, thus, can serve as sensitive tools for studying interfacial effects in
PNCs. By combining DS with calorimetry, we focus on structure/organization, thermal
transitions and dynamics of the polymer in the polymer-filler interfacial layer, determined to
be a few nm thick1. The basic system taken as example is poly(dimethylsiloxane)
(PDMS)/silica nanocomposites, prepared by following different routes in wide ranges of
composition. The strong (hydrogen bonding) polymer-filler interactions are found to affect
significantly the mobility of PDMS and to suppress crystallization2. Four contributions to the
segmental dynamics associated with the glass transition are observed and analyzed, arising, in
the order of decreasing mobility, from confined, bulk, restricted between condensed PDMS
crystals, and interfacial polymer. Distinct similarities and differences to other PNCs based on
rubbers, thermoplastics and thermosets, as well as correlations to results by other
spectroscopic techniques will be discussed.
REFERENCES
1. Klonos, P., Kyritsis, A., Pissis, P. Interfacial effects in polymer nanocomposites studied by thermal and
dielectric techniques, Chapter 6 in Interface/interphase in polymer nanocomposites, A.N. Netravali, K.L.
Mittal (Eds.), Series: Adhesion and Adhesives: Fundamental and Applied Aspects, WILEY - Scrivener
Publishing LLC, 2016, pp 191-248. (ISBN: 9781119184911)
2. Fragiadakis, D., Bokobza, L., Pissis, P., Polymer. 46, 6001- 6008 (2005).
Polym-Nanocom-2 ORAL CONTRIBUTIONS
Invited Talk
Dynamics in polymer nanocomposites
R. Casalini and C.M.Roland
Naval Research Laboratory, Chemistry Division, Washington DC, USA
We present results from recent studies of the effect on the polymer dynamics of nanoparticles.
We use a combination of macroscopic and nanoscopic experimental techniques, including
neutron, dielectric, and mechanical spectroscopies, calorimetry, AFM, and local dielectric
spectroscopy. In nanocomposites the particles cause substantial changes in the rheology,
including higher viscosities that become non-Newtonian and the appearance of stress
overshoots in the transient shear viscosity. However, no change was observed in the mean
relaxation times for either the segmental or normal mode dynamics measured dielectrically.
This absence of an effect of the particles is due to masking of the interfacial response by
polymer chains remote from the particles. When the unattached polymer was extracted to
isolate the interfacial material, very large reductions in the relaxation times were measured.
We also carried out the first direct measurements of the dynamics at the interface using
nanoscopic techniques.
ORAL CONTRIBUTIONS Polym-Nanocom-3
Invited Talk
Diffusion of Polymers and Nanoparticles in All Polymer
Nanocomposites
Mark Dadmun
Chemistry Department, University of Tennessee
Polymer nanocomposites provide a pathway to novel materials with tunable properties. With
a growing variety of nanoparticles available, research probing the influence of particle
deformability, morphology, and topology on the behavior of nanocomposites is also
increasing. In particular, the behavior of soft polymeric nanoparticles in polymer
nanocomposites has displayed unique behavior, but their precise performance depends
intimately on the internal structure and morphology of the nanoparticle.
We will discuss our studies that examine the role of nanoparticle rigidity or softness on the
impact of the presence of that nanoparticle on the diffusive behavior of linear polymer chains.
Our neutron reflectivity results clearly show that the inclusion of ~10 nm soft nanoparticles in
a polymer matrix (Rg ~ 20 nm) increases the diffusion coefficient of the linear polymer
chain.1 Surprisingly, thermal analysis shows that these nanocomposites exhibit an increase in
their glass transition temperature, which is incommensurate with an increase in free volume.
Therefore, it appears that this effect is more complex than a simple plasticizing effect.
Additionally, the diffusive properties of nanoparticles in polymer nanocomposites are largely
unknown and are often difficult to determine experimentally. To address this shortcoming,
we have developed a novel method to determine the tracer diffusion coefficient of soft
polystyrene nanoparticles in a linear polystyrene matrix.2 The results show that these
deformable nanoparticles most closely mimic the diffusive behavior of fractal
macromolecular architectures or microgels, where the transport of the nanoparticle relies on
the cooperative motion of neighboring linear chains. The less cross-linked, and thus more
deformable, nanoparticles diffuse faster than the more highly crosslinked nanoparticles of the
same size, presumably because the increased deformability allows the nanoparticle to distort
and fit into available space.
REFERENCES
1. B. Miller, A. Imel, W. Holley, D. Baskaran, J.W. Mays, M.D. Dadmun “The Role of Nanoparticle Rigidity
on the Diffusion of Linear Polystyrene in a Polymer Nanocomposite”, Macromolecules, 48, 8369-8375
(2015).
2. A.E. Imel, S. Rostom, W. Holley, D. Baskaran, J.W. Mays, M.D. Dadmun “The Tracer Diffusion
Coefficient of Soft Nanoparticles in a Linear Polymer Matrix” RSC Adv., 7, 15574-15581, (2017).
Polym-Nanocom-4 ORAL CONTRIBUTIONS
Invited Talk
Rheological Studies of Temporary Cross-linked Polymeric
Materials
Arlette Baljon and Mark Wilson
San Diefo State University, 5500 Campanile Drive, San Diego
Under certain conditions polymer nancomposites behave as temporary crosslinked polymers:
nanoparticles serve as crosslinks that form and break over time. Depending on the
concentration of the nanoparticles and the strength of their interaction with the polymers,
these materials exhibit either luid-like viscous to near solid-like elastic dynamics. Such
viscoelastic materials are commonly studied by quantifying the stress response imposed
through oscillatory shear deformation. Relatively small changes in external parameters, such
as temperature, concentration, or frequency and amplitude of oscillation, can result in large
transitions in the viscoelastic behavior. In our research, numerical simulations of temporary
cross-linked polymeric systems are utilized to study viscoelastic behavior. A hybrid molecular
dynamics, Monte Carlo (MC) algorithm is employed. Polymer chains are modeled as a
course grained bead-spring system. Functionalized end groups, at both ends of the polymer
chains, can form reversible bonds according to MC rules. At high temperatures the system is
shown to behave as a fluid. Decreasing the temperature below the micelle transition results in
a self-assembly of the system, forming a network that is transient in time. The nodes of this
network consist of aggregates of end groups, while links between aggregates are formed by
one or more bridging polymer chains. We report on the macrostructural changes in such a
polymer network that arise in response to an oscillatory shear. The stress response has been
obtained as a function of the oscillatory frequency and amplitude in both the linear and
nonlinear regimes. Macroscopic data are correlated with observed microscopic changes in the
structure and dynamics of the transient networks1,2
.
REFERENCES
1. Wilson, M., Rabinovitch, A, Baljon, A. Macromolecules. 48, 6313 (2015).
2. Billen J., Wilson M., Baljon A. Chemical Physics. 142, 7 (2015).
ORAL CONTRIBUTIONS Polym-Nanocom-5
Invited Talk
Relaxation processes and glass transition of 1,4-
polybutadiene confined between graphite walls: a
Molecular Dynamics simulation
W. Paul1, M. Solar
2, K. Binder
3
1Physik Institut, Martin Luther University, 06099 Halle, Germany
2Institut Charles Sadron, Université Strasbourg, F-67034 Strasbourg, France
3Physik Institut, Johannes Gutenberg University, 65099 Mainz, Germany
Molecular dynamics simulations of a chemically realistic model for 1,4-polybutadiene in a
thin film geometry confined by two graphite walls are presented. Previous work on melts in
the bulk has shown that the model faithfully reproduces static and dynamic properties of the
real material over a wide temperature range. The present work studies how these properties
change due to nano-confinement. The focus is on orientational correlations observable in
dielectric1 or nuclear magnetic resonance experiments and on the local intermediate
incoherent neutron scattering function for distances z from the graphite walls in the range of a
few nanometers. Temperatures from about 2Tg down to about 1.15Tg, where Tg is the glass
transition temperature in the bulk, are studied. It is shown that weakly attractive forces
between the wall atoms and the monomers suffice to effectively bind a polymer coil that is
near the wall. This creates a dielectric normal-mode like process in the polymer2 which in the
bulk is a type-B one. The α-process is modified only for z ≤ 1.2 nm due to the density changes
near the walls, less than expected from studies of coarse-grained (bead-spring-type) models
and leading to an unchanged estimate for Tg for the film3. The weakness of the surface effects
on the glass transition in this case is attributed to the interplay of density changes near the
wall with the torsional potential.
REFERENCES
1. Solar, M., Mapesa, E. U., Kremer, F., Binder, K., Paul, W., The dielectric α-relaxation in polymer films: A
comparison between experiments and atomistic simulations, Europhys. Lett. 104, 66004 (2013).
2. Solar, M., Paul, W., Chain relaxation in thin polymer films: turning a dielectric type-B polymer into a type-
A’ one, Soft Matter. 13, 1646 (2017)
3. Solar, M., Binder, K., Paul, W, Relaxation processes and glass transition of confined polymer melts: A
molecular dynamics simulation of 1,4-polybutadiene between graphite walls, J. Chem. Phys. 146, 203308
(2017)
Polym-Nanocom-6 ORAL CONTRIBUTIONS
Invited Talk
Progress in multi-scaled structure and related properties of
polymer nanocomposites explored by molecular dynamics
simulation
Jun Liu
Beijing University of Chemical Technology, Beijing, People's Republic of China
In this talk I will systematically present some important simulated results of elastomer nanocomposites
(ENCs) achieved via molecular dynamics simulation. First, we studied the dispersion and aggregation
behavior of bare nanoparticles(NPs) with different geometries such as spherical, sheet-like and rod-
like on the molecular scale. To model small ligands used in experiments to realize better dispersion,
we investigated the dispersion of NPs end-grafted with polymer chains by varying the grafted chain
length and grafting density. In addition, the effect of the middle- and end-functionalization on the
dispersion of NPs is also covered. Second, we probed the translational and relaxation dynamics at the
chain and segmental length scales of the interfacial regions, hoping to elucidate whether “glassy
polymer layers” exist around NPs. Third, we simulated the enhancement of the stress-strain and
fracture toughness induced by NPs, providing a molecular reinforcing mechanism. Fourth, the famous
“Payne effect”, namely the decrease of the storage modulus as a function of the strain amplitude was
examined, uncovering the underlying reason responsible for this non-linear behavior, and meanwhile
how the introduced carbon nano-springs can effectively reduce the dynamic hysteresis of ENCs is
illustrated. Fifth, through simulation synthesis approach, we put forward a new and achievable
approach to design and prepare a nanoparticle chemical network, with the NPs acting as “giant cross-
linkers” or netpoints to chemically connect the dual end-groups of each polymer chain to form a
network. We find this new network structure possesses excellent static and dynamic mechanical
properties, highlighting a ultralow dynamic hysteresis loss tailored for green automobile tires.
Computer simulation is shown to have the capability to obtain some fundamental understanding of
ENCs, in hopes of providing some design basis and principles for synthesizing and fabricating multi-
functional and high performance ENCs. In the meanwhile, I will show the preparation, structure-
property relation and their industrialization of various high performance elastomer nanocomposites
filled with clay, fibrillar silicate, silica, carbon nanotubes and graphene.
REFERENCES
1. Wang, Z.H., Liu, J., Zhang, L.Q., et al Phys. Chem. Chem. Phys. 12, 3014 (2010)
2. Liu, J., Cao, D.P., Zhang, L.Q., et al Macromolecules. 42, 2831 (2009).
3. Liu, J., Cao, D.P., Zhang; L.Q., et al Phys. Chem. Chem. Phys. 13, 13058 (2011).
4. Liu, J., Zheng, Z. J., Zhang, L. Q., Wang, Z. L., Nano Energy. 28; 87–96 (2016)
ORAL CONTRIBUTIONS Polym-Nanocom-7
Invited Talk
Variations of cooperativity in dependence with morphology
and microstructure for a semi-crystalline PLA
nanocomposite
A. Saiter1, N. Delpouve
1, E. Dargent
1, W. Oberhauser
2, L. Conzatti
3,
F. Cicogna4, E.Passaglia
4
1 Normandie Univ, UNIROUEN, INSA ROUEN, CNRS, Groupe de Physique des Matériaux,
76000 Rouen, France
2ICCOM-CNR Firenze,Via Madonna del Piano 10, 50019 Sesto Fiorentino, Firenze, Italy
3ISMAC-CNR Genova, via De Marini 6 16149 Genova, Italy
4ICCOM- CNR UOS Pisa, Via G. Moruzzi 1, 56124 Pisa, Italy
In the theory of Adam and Gibbs [1] the main relaxation process occurs in cooperative
rearranging regions (CRR). A CRR is defined as the smallest subsystem in which the main
relaxation process occurs independently on the dynamics of the neighboring subsystems.
Among the numerous models and theories aiming at estimating the size of a CRR, the
approach of Donth [2] offers an empiric opportunity to calculate it directly from thermal
analysis methods. The idea of this work is to use the CRR concept to probe the
macromolecule organization in the amorphous phase of polylactide (PLA) from the simplest
case of a PLA wholly constituted of mobile amorphous phase that fully relaxes at the glass
transition, to the highly complex case of semi-crystalline nanocomposites in which the
relaxation of the amorphous phase is hindered by the crystals, the fillers and even sometimes
additives. In amorphous nanocomposites our investigations reveal a high dependence of the
cooperativity with the interfacial interactions, i.e., the filler dispersion. In semi-crystalline
systems, the cooperative dynamics become dominated by the microstructure independently on
the initial sample morphology and the strongest drop of the cooperativity was observed for
crystallization conditions favoring the coupling between amorphous and crystals [3].
REFERENCES
1. Adam, G., Gibbs, J.H., On the temperature dependence of cooperative relaxation properties in glass-
forming liquids, Journal of Chemical Physics. 43, 139-146 (1965).
2. Donth, E., The size of cooperatively rearranging regions at the glass transition, Journal of Non-Crystalline
Solids. 53, 325-330 (1982).
3. Saiter, A., Delpouve, N., Dargent, E., Oberhauser, W., Conzatti, L., Cicogna, F., Passaglia, E., Probing the
chain segment mobility at the interface of semi-crystalline polylactide/clay nanocomposites, European
Polymer Journal. 78, 274-289 (2016).
Polym-Nanocom-8 ORAL CONTRIBUTIONS
Invited Talk
Structure of chains and filler in polymer nanocomposites:
impact of small beads and small molecules
D. Musino, A.C. Genix, G. Baeza, A. Banc, J. Oberdisse
Laboratoire Charles Coulomb (L2C), CNRS, Université de Montpellier, 34090 Montpellier
France
Polymer nanocomposites are mixtures of nanoparticles and polymer chains, where the filler
particles are usually added to enhance mechanical properties, e.g. of car tire materials.
Performance depends to a great extent on the structure of the filler, i.e. its dispersion state in
the polymer matrix, which itself depends on mixing protocols, but also on the
thermodynamics of the system. The latter can be tuned by performing either chemical surface
modifications of the nanoparticles, or by playing with the mass and/or grafting properties of
the polymer chains. In this talk, some straightforward ways to obtain information from small-
angle scattering on the structure of nanocomposites will be presented [1].
In particular, we will review recent results on nanocomposites close to industrial applications,
including what is probably one of the first quantitative analyses of such disordered structures
by a combination of SAXS, TEM and numerical simulations [2]. This analysis will then be
applied to the impact of small molecules on such structures [3]. Concerning chain structure, a
quick outlook on why contrast-matching with SANS in nanocomposites often fails will be
proposed [4].
REFERENCES
1. Genix, A.-C., and Oberdisse, J., Structure and dynamics of polymer nanocomposites studied by X-ray and
neutron scattering techniques. Current Opinion in Colloid & Interface Science. 2015, 20, 293-303 (2015).
2. Baeza, G. P., Genix, A. C., Degrandcourt, C., Petitjean, L., Gummel, J., Couty, M. and Oberdisse, J.,
Multiscale Filler Structure in Simplified Industrial Nanocomposite Silica/SBR Systems Studied by SAXS
and TEM, Macromolecules. 46, 317-329 (2013).
3. Musino, D., Genix, A.-C., Fayolle, C., Papon, A., Guy, L., Meissner, N., Weda, P., Bizien, T., Chaussée, T.,
Oberdisse, J., Synergistic effect of small molecules on large-scale structure of simplified industrial
nanocomposites, submitted.
4. Banc, A., Genix, A.-C., Dupas, C., Sztucki, M., Schweins, R., Appavou, M.-S., Oberdisse, J., Origin of
small-angle scattering from contrast-matched nanoparticles: A study of chain and filler structure in polymer
nanocomposites, Macromolecules. 48, 6596−6605 (2015).
ORAL CONTRIBUTIONS Polym-Nanocom-9
Oral
Anisotropic dynamics in confined fluids
Yuriy Chushkin1, Kim Nygård
2, Johan Buitenhuis
3, Matias Kagias
4,5,
Konstantins Jefimovs4,5
, Federico Zontone1
1 European Synchrotron Radiation Facility, 71 Avenue des Martyrs, F-38000, Grenoble,
France
2 Department of Chemistry and Molecular Biology, University of Gothenburg, SE-41296,
Gothenburg, Sweeden
3 Forschungszentrum Jülich, ICS-3, D-52425, Jülich, Germany
4 Paul Scherrer Institute, CH-5232, Villigen PSI, Switzerland
5 Institute for Biolmedical Engineering, UZH/ETH Zürich, CH-8092, Zürich, Switzerland
Dense fluids in narrow spatial confinement exhibit complex microscopic ordering, due to
competing packing constraints imposed by the confining surfaces and other particles in the system
[1]. As a result, confinement alters the fluids’ dynamic properties [2] and is thus highly relevant in
a wide range of scientific phenomena and technological applications. Packing constraints in
confined geometries lead to a position-dependent diffusion of dense fluids, thereby highlighting
the close connection between microscopic structure and dynamics. However, a conceptually
simple mechanistic picture describing complex dynamical behavior [3] in terms of the
microscopic structure is still missing.
We studied the connection between the microscopic structure and dynamics of dense fluids
confined between planar walls at close separation, i.e., in a narrow slit geometry by combining
high-energy (21 keV) x-ray photon correlation spectroscopy and small-angle x-ray scattering from
colloid-filled microfluidic channels [4]. The results show the structural relaxation in confinement
to be slower compared to bulk. The collective dynamics is wave vector dependent, akin to de
Gennes narrowing typically observed in bulk fluids. However, in stark contrast to bulk, the
structure factor [5] and de Gennes narrowing in confinement are anisotropic. These experimental
observations establish a direct connection between the structure and dynamics in confined fluids
at the fundamental level of anisotropic pair densities, and thereby provide an important conceptual
step towards a microscopic description of collective diffusion in dense confined fluids.
REFERENCES
1. Henderson, D., ed., Fundamentals of Inhomogeneous Fluids New York: Marcel Dekker, (1992).
2. Granick, S., Motions and Relaxations of Confined Liquids, Science. 253, 1374 (1991).
3. Lang, S., et al., Glass Transition in Confined Geometry, Phys. Rev. Letter. 105,125701 (2010).
4. Nygård, K., et al., Anisotropic de Gennes Narrowing in Confined Fluids, Phys. Rev. Letters. 116, 167801 (2016).
5. Nygård, K., et al., Anisotropic Pair Correlations and Structure Factors of Confined Hard-Sphere Fluids: An
Experimental and Theoretical Study, Phys. Rev. Letters. 108, 037802 (2012).
Polym-Nanocom-10 ORAL CONTRIBUTIONS
Oral
Silver nanoplates for electrically conductive sizing in
PEEK/Carbon Fiber composites
Jérémie Audoit, Antoine Lonjon, Eric Dantras, Colette Lacabanne
Physique des Polymères–CIRIMAT, Université Paul Sabatier,
118 Route de Narbonne, 31062 Toulouse, France
The improvement of electrical conductivity of carbon fiber reinforced polymer composites may be
obtained by introducing conductive nanofillers at the interface between the polymeric matrix and the
carbon fibers. Prior the manufacturing of composites, a polymeric sizing is deposited onto the carbon
fiber surface. A dispersion of 2d metallic nanofillers into the polymer sizing was used.
Silver nanoplates are known for their optical properties, such as plasmon resonance, but their use as
conductive nanofiller is more recent [1]. Silver nanoplates were produced via a seed-mediated
protocol. Large silver nanoplates (AgNpts) were obtained with a mean size around 1 µm. Nanoplates
exhibit a moderate aspect ratio (length over thickness) from 12 to 25. The introduction of various
content of AgNpts into a model polymer – Polyvinylidene fluoride (PVDF) – gave a series of
nanocomposites allowing us the investigation of electrical conduction. An electrical percolation
phenomenon was observed for both volume and surface conductivity. The percolation parameters
were determined from a power law. The volume percolation threshold was observed at 5.9 vol.%,
while the surface percolation threshold was observed at 6.9 vol.%. Samples with silver content above
the percolation threshold reached a very high conductivity (> 100 S.m-1)
AgNpts were then introduced into the polymer sizing and deposited on the carbon fiber
surface. A comparative study of composites with PEEK matrix and sized fibers with and
without AgNpts was performed. Composites with conductive sizing exhibit a tenfold higher
conductivity level at very low AgNpts content (< 0.2 vol.%) so mechanical properties are
maintained [2].
Acknowledgements
The authors gratefully acknowledge the financial support of BPI/France and Conseil Régional Midi
Pyrénées/France through the MACOTHEC FUI program.
REFERENCES
1. Audoit, J., Laffont, L., Lonjon, A., Dantras, E., Lacabanne C., Percolative silver nanoplates/PVDF
nanocomposites: Bulk and surface electrical conduction, Polymer.78, 104–110, (2015).
2. Audoit, J., Optimization of transverse electrical conductivity for structural composites PAEK–Silver
nanowires / carbon fiber with electrically conductive sizing, PHD, Université Paul Sabatier, (2017)
ORAL CONTRIBUTIONS Polym-Nanocom-11
Invited Talk
Polymer Chain Conformation and Dynamical Confinement
in a Model One Component Nano Composite
Dieter Richter1, Christian Mark
1, Michael Monkenbusch
1, Olaf Holderer
2,
Jürgen Allgaier1, Nina Jalarvo
3, Michaela Zamponi
2, Aurel Radulescu
2
1 Jülich Centre for Neutron Science (JCNS) & Institute for Complex Systems (ICS),
Forschungszentrum Jülich GmbH, 52428 Jülich, Germany
2 Forschungszentrum Jülich GmbH, JCNS at Heinz Maier-Leibnitz Zentrum
Lichtenbergstraße 1, 85747 Garching, Germany
3 Forschungszentrum Jülich GmbH, JCNS at SNS-Oak Ridge National Laboratory (ORNL),
1 Bethel Valley Road, Oak Ridge, TN, 37831 USA
We report a neutron scattering investigation on the structure and dynamics of a single
component nano composite (OCNC) based on SiO2 particles that were grafted with
polyisoprene (PI) chains at the entanglement limit. By skillful labeling we accessed both the
monomer density in the corona as well as the conformation of the grafted chains. While the
corona profile follows an r-1
power law, the conformation of a grafted chain is identical to that
of a chain in a reference melt, implying a high mutual penetration of the coronas from
different particles. The brush crowding leads to topological confinement of the chain
dynamics: (i) At local scales the segmental dynamics is unchanged compared to the reference
melt, while (ii) at the scale of the chain the dynamics appears to be slowed down; (iii)
performing a mode analysis in terms of end fixed Rouse chains the slower dynamics is
tracked to topological confinement within the cone spanned by the adjacent grafts; (iv) adding
50% matrix chains the topological confinement sensed by the grafted chain is lifted partially
and the apparent chain motion is accelerated: We observe a cross over from pure Rouse
motion at short times to topological confined motion beyond the time, when the segmental
MSD has reached the distance to the next graft.
Polym-Nanocom-12 ORAL CONTRIBUTIONS
Invited talk
Thermal connectivity and electrical percolation in
PEEK/nAg nanocomposites
Lisa Riviere, Jérémie Audoit, Antoine Lonjon, Eric Dantras, Colette
Lacabanne
Physique des Polymères–CIRIMAT, Université Paul Sabatier,
118 Route de Narbonne, 31062 Toulouse, France
A comparative study of electrical and thermal conduction mechanisms in PEEK/nAg
nanocomposites will be presented. A specific attention has been paid to the influence of
particles aspect ratio: from silver nanospheres AgNPs (aspect ratio ξ = 1) to silver nanowires
AgNWs(ξ = 250).The electrical percolation threshold decreases from 10 vol% for AgNPs to
less than 1 vol% for AgNWs [1]. The electrical conductivity undergoes a step of 12 decades
and the maximum value (σ = 300 S.m-1
) is abruptly reached after percolation for various filler
morphologies [1–2]. AgNWs strongly favor the building of the percolation path at very low
filler content.
Thermal conductivity also strongly depends on particles aspect ratio. For PEEK/AgNWs
composites thermal conductivity reaches λ = 1 W.m-1
.K-1
for 8 vol %while it is only
λ = 0.5 W.m-1
.K-1
for AgNPs. This evolution of heat transport has been attributed to a change
of connectivity. It is interesting to mention that the thermal conductivity varies linearly with
the filler content. Heat transport is promoted by a dense metallic network [2].
Electrical and thermal conduction are described by different laws that confirm they are driven
by different mechanisms. Nevertheless, both are favored by high aspect ratio fillers.
Acknowledgements
The authors gratefully acknowledge the financial support of BPI/France and Conseil Régional Midi
Pyrénées/France through the MACOTHEC FUI program.
REFERENCES
1. Rivière, L., Lonjon, A., Dantras, E., Lacabanne, C., Olivier, P., Rocher Gleizes, N., Silver fillers aspect ratio
influence on electrical and thermal conductivity in PEEK/Ag nanocomposites, European Polymer Journal.
(2016).
2. Audoit, J., Laffont, L., Lonjon, A., Dantras, E., Lacabanne C., Percolative silver nanoplates/PVDF
nanocomposites: Bulk and surface electrical conduction, Polymer.78, 104–110, (2015).
3. Rivière, L., Analysis of thermal conduction mechanisms in structural PEEK / silver submicronic filler
composites, Université Paul Sabatier, France (2016).
ORAL CONTRIBUTIONS Polym-Nanocom-13
Invited Talk
Quantification and interpretation of different contributions
to dissipation and reinforcement in rubber composites
Sriharish M. Nagaraja,1 Anas Mujtaba,
1 Mario Beiner
1,2
1Fraunhofer-Institut für Mikrostruktur von Werkstoffen und Systemen IMWS
Walter-Hülse-Straße 1, 06120 Halle, Germany
2Martin-Luther-Universität Halle-Wittenberg, Naturwissenschaftliche Fakultät II
Heinrich-Damerow-Str. 4, 06120 Halle, Germany
Strain sweeps of the storage modulus measured at different temperatures and frequencies for
various series of highly filled rubber composite clearly indicate that the filler network shows
viscoelastic properties. This observation has been explained by the existence of glassy rubber
bridges between neighbored nanoparticles being part of the filler network [1,2]. These glassy
bridges soften gradually with raising temperature or decreasing measurement frequency leading to
visco-elastic properties. The strength of these glassy rubber bridges obviously determines the
load-carrying capacity of the filler network. More recent studies focus on a quantification of
different contributions to dissipation in natural rubbers filled with carbon black or carbon
nanotubes. Data for the loss modulus from strain sweeps are well approximated by a modified
Kraus equation [3]. This allows to separate and quantify different contributions to dissipation. It
will be demonstrated that glassy rubber bridges are also of major importance for the dissipation
behavior of rubber composites. There are not only dissipative contributions if bridges in the filler
network break at large strain amplitudes as already proposed by Kraus [4] but there are also
dissipative contributions at small strain amplitudes being related to the oscillatory deformation of
intact bridges [3]. Correlations between both contributions to the overall dissipation are analyzed
applying the proposed model based on the modified Kraus equation. Final conclusion is that both
dissipative contributions are proportional to the total number of glassy rubber bridges N0 which
depends on filler content and temperature. This is an important finding and should be relevant for
the optimization of rubber composites for special applications like tire treads.
REFERENCES
1. Mujtaba, A. et al., Mechanical properties and cross-link density of styrene-butadiene model composites containing
fillers with bimodal particle-size distribution, Macromolecules. 45, 6504-6515 (2012).
2. Mujtaba, A. et al., Detection of surface-immobilized components and their role in viscoelastic reinforcement of
rubber−silica nanocomposites, ACS Macro Letters. 3, 481-485 (2014).
3. Nagaraja, S.M. et al., Quantification of different contributions to dissipation in elastomer nanoparticle composites,
Polymer. 111, 48-52 (2017).
4. Kraus, G. Mechanical losses in carbon black filled rubbers, J. Appl. Polym. Sci.: Appl. Polym. Symp. 39, 75-92
(1984).
Polym-Nanocom-14 ORAL CONTRIBUTIONS
Invited Talk
Nanocomposites with Grafted Nanoparticles
Sanat K. Kumar
Department of Chemical Engineering, Columbia University New York, NY
A central area of research in the soft matter community is in inorganic/organic hybrid
materials with nanoscale inorganic particles. These materials have been focused on due to
their promise of having synergistic thermal, mechanical and optical properties relative to the
pure materials. It is now accepted that the spatial distribution of the inorganic nanoparticles
critically affect the properties of the resulting materials, but a grand challenge is to control the
spatial distribution of the inorganic, hydrophilic nanoparticles in the organic, hydrophobic
polymer matrix. I focus on one particular approach to controlling nanoparticle spatial
dispersion, the use of polymer-grafted nanoparticles. In the case where the NP and the grafted
polymer chains energetically “dislike” each other, we have an architecture akin to a
microphase separated block copolymer or a surfactant. Analogous to these “surfactants” these
grafted nanoparticles also assemble into a range of morphologies, thus giving us the
unprecedented ability to control the particle dispersion state.
In this talk I first focus on the factors controlling this assembly and use this knowledge to
consider the utility of other approaches to self-assembly – we show that the use of
crystallizable polymers allows us to control nanoparticle order, in particular by varying the
rate at which these materials crystallize. This allows us to mimic the growth of organisms
such as nacre and oysters, whose shells combine the dual advantages of high strength and
toughness. In a different vein, these grafted nanoparticles show the ability to creating
membranes that have the potential to revolutionalize the separation of hydrocarbons and in
carbon sequestration.
ORAL CONTRIBUTIONS Proc-SR-Boson-1
Invited Talk
The Johari-Goldstein Process and Structural Relaxation
C.M. Roland, D. Fragiadakis, and R. Casalini
Naval Research Laboratory, Washington DC 20375-5340
The Johari-Goldstein (JG) secondary relaxation is ubiquitous among glass-forming materials,
with every atom in the molecule participating, even though not every molecule may undergo
the JG process.1 The fact that the JG relaxation precedes the -relaxation, together with
various connections between their respective properties, suggests that the JG process may
function as the precursor of the glass transition.2 These property connections are limited
mainly to average properties; for example, there is no correlation between the JG and α
relaxation times of individual molecules.3 Nevertheless, measurements of the JG relaxation
below Tg can yield information about the relaxation that is not accessible directly.
Previously we found that the time constant associated with changes in the JG process during
physical aging of a glass can be identified with the relaxation time.4 In this work we use
pressure-densification to change the glass structure5. Employing both experiments and
molecular dynamics simulations, we investigate how the glass structure affects the JG
dynamics and by inference the relaxation. Such information is relevant to the 100-year-old
problem of what governs glass formation.
REFERENCES
1. Fragiadakis, D., Roland, C.M., Participation in the Johari−Goldstein Process: Molecular Liquids versus
Polymers, Macromolecules. in press (2017).
2. Ngai, K.L., Relaxation and Diffusion in Complex Systems, Springer (2011).
3. Fragiadakis, D., Roland, C.M. Role of Structure in the and Dynamics of a Simple Glass-Forming
Liquid, Phys. Rev. E, 95, 022607 (2017).
4. Casalini, R., Roland, C.M. Aging of the Secondary Relaxation to Probe Structural Relaxation in the Glassy
State, Phys. Rev. Lett. 102, 035701 (2009).
5. Casalini, R., Roland, C.M. Anomalous Properties of the Local Dynamics in Polymer Glasses, J. Chem.
Phys. 131, 114501 (2009).
Proc-SR-Boson-2 ORAL CONTRIBUTIONS
Oral
A Simple Framework for Connecting Microscopic
Picosecond Relaxation Events to Macroscopic Relaxation
and Transport
Marcus T Cicerone
US National Institute of Standards and Technology
100 Bureau Drive, Gaithersburg MD 20899 USA
Through neutron scattering, nonlinear optical methods, and computer simulation, we have
shown that collective motions characteristic of metabasin transitions, or equivalently, Johari-
Goldstein relaxation, constitute the basis of spatially heterogeneous dynamics. This local
mode dominates α relaxation and transport in supercooled liquids and glasses, but is also of
great importance in liquids at least up to TA (the Arrhenius temperature). I will present
timescale and lengthsale characterization of this local relaxation mode.[1] I will also present a
framework [2] from which these picosecond measurements can be used to predict relaxation
over 12 orders of magnitude in time. The proposed framework suggests that serial, spatially
heterogeneous microscopic relaxation processes are a key feature of not only the supercooled
liquid and glass, but of the high temperature liquid as well.
REFERENCES
1. Cicerone, M. T., and Tyagi, M., Metabasin transitions are Johari-Goldstein relaxation events, Journal of
Chemical Physics. 146, 54502 (2017).
2. Cicerone, M. T., and Zhong, Q., and Tyagi, M., Picosecond Dynamic Heterogeneity, Hopping, and Johari-
Goldstein Relaxation in Glass-Forming Liquids, Physical Review Letters. 113, 117801 (2014).
ORAL CONTRIBUTIONS Proc-SR-Boson-3
Invited Talk
Sub-Tg transition of caged molecule dynamics in glass-
forming systems caused by coupling to JG β-relaxation:
carbohydrates and solvated proteins
S. Capacciolia, A. Paciaroni
b, K.L. Ngai
a
aPhysics Dept. Pisa University & CNR-IPCF, Largo B. Pontecorvo 3, 56127, Pisa, Italy
bPhysics Dept. Università di Perugia & IOM-CNR, Via A. Pascoli 1, 06123 Perugia, Italy
Recent studies on the fast dynamics in the glassy state of polyalcohols [1], amorphous
polymers, van der Waals molecules and metallic alloys have shown that the caged dynamics
appear in susceptibility losses as a frequency power law with a small exponent [2]. It has been
also shown that generally the intensity of the fast caged dynamics changes temperature
dependence at a temperature THF nearly coincident with the secondary glass transition
temperature Tg occurring when the Johari-Goldstein (JG) -relaxation time reaches 1 ks.
The phenomenon is remarkable since THF is determined usually by measurements of fast
caged dynamics at short timescales (typically in the ns-ps range), such as neutron scattering,
THz absorption, Brillouin light scattering, while Tg is determined directly by calorimetry,
low frequency dielectric and mechanical relaxation spectroscopy. The outstanding property of
THFTg follows as consequence of the density dependence of the caged dynamics and the
coupling to the JG -relaxation, whose relaxation time is in turn affected by density. The
caged dynamics regime is always terminated by the onset of the JG -relaxation, and hence
the origin of the coupling. The present study extends the generality of the property and its
explanation to new systems relevant for biopreservation, such as carbohydrates and solvated
proteins. From these systems we show data from incoherent neutron scattering and terahertz
dielectric spectroscopy that confirm the same property as found in the other glass-formers, i.e.
THFTg. These findings may have positive impact in understanding how to prevent
degradation of proteins when embedded in glassy matrices.
REFERENCES
1. Sibik, J., Elliott, S.R., Zeitler, J.A., Thermal decoupling of relaxation processes from the vibrational density
of states at THz frequencies in H-bonded liquids, J. Phys. Chem. Lett. 5, 1968−1972 (2014).
2. Capaccioli, S., Ngai, K. L., Shahin Thayyil, M. , Prevosto, D., Coupling of Caged Molecule Dynamics to JG
β‐Relaxation: I, J. Phys. Chem. B 119, 8800–8808 (2015); Ngai, K. L., Capaccioli, S., Prevosto, D., Wang,
L-M, Coupling of Caged Molecule Dynamics to JG β‐Relaxation: II+III, J. Phys. Chem. B 119,
12502+12519 (2015); Wang, Z., Ngai, K. L., Wang, W.H., Capaccioli, S., Coupling of caged molecule
dynamics to Johari-Goldstein -relaxation in metallic glasses, J. Appl. Phys. 119, 024902 (2016).
Proc-SR-Boson-4 ORAL CONTRIBUTIONS
Invited Talk
Inflection in pressure dependence of protic ionic liquid
conductivity
Erik Thoms,1,2
Żaneta Wojnarowska,1,2
Peter Goodrich,3 Johan Jacquemin,
3
and Marian Paluch1,2
1Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland.
2Silesian Center for Education and Interdisciplinary Research, 75 Pulku Piechoty 1A, 41-500
Chorzow, Poland.
3The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen’s
University of Belfast, Stranmillis Road, Belfast BT9 5AG, United Kingdom.
Ionic liquids (ILs) are salts with melting points around or below room temperature, many of
them typical glass formers. They exhibit a multitude of interesting properties, making them
promising candidates, e.g., as solvents, replacing volatile organic compounds, or as
electrolytes in energy storage devices. For many of those potential applications, the ionic
conductivity of ILs is a key parameter, resulting in a number of publications on this topic,
which consider, e.g., the influence of ion structures, water content, confinement, glass
properties, or IL-mixtures. Most of these, however, solely include ambient pressure data. A
systematic analysis of both the temperature and the pressure dependence of the glass
transition allows to separate the effects on local motion provided by molecular packing and by
available energy. Therefore, elevated pressure measurements are an important tool for
understanding this process.
Temperature and pressure dependent broadband dielectric measurements were performed on
the protic ionic liquids (PILs) CnHIM NTf2 (n = 6, 8, 10) over a frequency range from 0.1 Hz
to 1 MHz. The temperature dependence of the inverse dc-conductivity exhibits the
superarrhenius like behaviour typical for glass forming materials. However, in the pressure
dependence both slower and faster than exponential developments can be clearly observed for
n = 6 and 8, resulting in an inflection in the corresponding curves. Most interestingly, the
same behaviour could be detected in the classical glass forming molecular liquid propylene
carbonate. While similar transitions have been observed in the pressure dependent viscosity or
structural relaxation times, such behaviour has not been reported in the conductivity before.
ORAL CONTRIBUTIONS Proc-SR-Boson-5
Invited Talk
Universal glassy anomalies in the low-temperature thermal
properties of disordered crystalline solids
J. F. Gebbia1, M. Romanini
1, R. Macovez
1, L.C. Pardo
1, M. Barrio
1, M. A.
Ramos2, A. I. Krivchikov
3, F. J. Bermejo
4, J. Ll. Tamarit
1,*
1 Grup de Caracterizació de Materials, Departament de Fisica, EEBE and Barcelona Research
Center in Multiscale Science and Engineering, Universitat Politècnica de Catalunya, Eduard
Maristany, 10-14, 08019 Barcelona, Catalonia, Spain 2 Laboratorio de Bajas Temperaturas, Departamento de Física de la Materia Condensada,
Condensed Matter Physics Center (IFIMAC) and Instituto Nicolás Cabrera, Universidad
Autónoma de Madrid, Francisco Tomás y Valiente 7, 28049 Madrid, Spain 3 B. Verkin Institute for Low Temperature Physics and Engineering of NAS Ukraine, 47
Science Avenue, Kharkov 61103, Ukraine 4 Instituto de Estructura de la Materia, Consejo Superior de Investigaciones Científicas, CSIC,
Serrano 123, 28006 Madrid, Spain
The freezing of the cooperative reorientational motions in orientationally disordered
molecular crystals gives rise to the so-called “glassy” transition, known as the lower-
dimensional version of the structural glass transition.1,2
While structural glasses display both
positional and orientational disorder, orientational glasses involve exclusively disorder of the
orientational degrees of freedom of the molecular entities, and the molecular centers of mass
forming an ordered lattice. We report here on low-temperature thermal and transport
properties, relaxation dynamics and the vibrational density of states of crystals exhibiting
minimal occupational disorder. Despite in these systems a few number of degrees of freedom
concerning the occupational site disorder are frozen, universal glassy features appeared.3-6
Our studies clearly reveal that all the low-temperature glassy anomalies can be found in these
systems with minimal disorder. Our findings should pave the way to a deeper understanding
of the origin of well-known described universal glassy properties.
REFERENCES
1. Brand, R., Lunkenheimer, P., Loidl, A., J. Chem. Phys. 116, 10386−10401 (2002).
2. Vispa, A., Romanini, M., Ramos, M.A., Pardo, L.C., Bermejo, F.J., Hassaine, M., Krivchikov, A.I., Taylor, J.W.,
Tamarit, J.Ll., Phys. Rev. Lett. 118, 105701 (2017).
3. Romanini, M., Barrio, M., Capaccioli, S., Macovez, R., Ruiz-Martin, M.D., Tamarit, J.Ll. J. Phys. Chem. C 120,
10614−10621 (2016).
4. Zuriaga, M., Pardo, L.C., Lunkenheimer, P., Tamarit, J.Ll., Veglio, N., Barrio, M., Bermejo, F.J., Loidl, A., Phys.
Rev. Lett. 103, 075701 (2009).
5. Romanini, M., Negrier, Ph., Tamarit, J.Ll., Capaccioli, S., Barrio, M., Pardo, L.C., Mondieig, D., Phys. Rev. B 85,
134201 (2012).
6. Ben Hassine, B., Negrier, Ph., Romanini, M., Barrio, M., Macovez, R, Kallel, A., Mondieig, D., Tamarit, J.Ll.,
PCCP 18, 10924—10930 (2016)
Proc-SR-Boson-6 ORAL CONTRIBUTIONS
Invited Talk
Relaxation dynamics in orientationally disordered crystals:
Hexa-substituted benzenes
S.S.N. Murthy and Abhishek K. Singh
School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067
Molecular orientation is known to occur in Benzene and hexa-sustituted benzeness (HSBs)
irrespective of whether there is orientational disorder or not as proved in NMR - and dielectric
- relaxation measurements.1,2
The dynamics in orientationally disordered phase of many
HSBs, and their substitutional solid solutions is studied employing dielectric spectroscopy and
differential scanning calorimetry. The orientational disordered phase is found to be less
symmetric as monoclinic- or , triclinic- or , or rhombohedral- in structure using X-ray
diffraction studies. The deviation of the temperature dependence of the structural relaxation
rates from the Arrhenius law is less pronounced in these materials as compared to
orientationally disordered cubic phases of cyanocyclohexane etc.2,3
In the dielectric relaxation
spectra of HSBs, the α-relaxation is always accompanied by an additional ( β-relaxation )
process on the higher frequency side, whose relaxation rates differ from that of α-relaxation
by 2-3 orders only, and is more or less as predicted by the coupling model of Ngai.4 We
compare our dielectric results with the NMR (nuclear magnetic resonance) relaxation results
(wherein the latter no secondary process has been reported so far), and speculate on the origin
of this additional β-relaxation process characteristic of HSBs.
REFERENCES-
1. Brot, C., and Lassier-Covers, B., Ber. Bunsenges. Phys. Chem. 80 (1976) 31.
2. Singh, A. K., and Murthy, S.S.N., Thermochim. Acta 604 (2015) 33.
3. Romanini, M., Barrio, M., Capaciolli, S., Macovez, R., Ruiz-Martin, M. D., and Tamarit, J. L., J. Phys.
Chem. C 120 (2016) 10614.
4. Ngai, K. L., Relaxation and Diffusion in Complex Systems, Springer (New York, Dordrecht, Heidelberg,
London) 2011.
ORAL CONTRIBUTIONS Proc-SR-Boson-7
Invited Talk
Evidence of JG relaxation in poly(styrene) glass by dynamic
heat capacity - quenching and aging effects
Elpidio Tombari
CNR-IPCF, Institute for Chemical-Physical Processes, Via Moruzzi 1, 56124 Pisa, Italy
Local region fluctuations known as -, or JG-relaxation in a glass structure are unobservable
in heat capacity, Cp, data because the enthalpy loss on structural relaxation overwhelms its
broad and weak Cp-endotherm. It was shown that the Cp-endotherm from JG-relaxation can be
observed by normal calorimetry when it is widely separated from the glass-liquid transition
endotherm.1 Since irreversible heat flow due to enthalpy relaxation on heating a glass does
not affect its dynamic Cp, one expects that measurement of dynamic Cp can be used to reveal
JG relaxation in all glasses. By measuring the real and imaginary components of complex
heat capacity, Cp' and Cp", we observe this relaxation in poly(styrene), which we use as a
model glass former. Starting from the melt, we formed its four glasses, glass I was formed by
cooling at 12 K/h to 275 K, glass II formed by cooling at 12 K/h to 360 K,then annealing for
120 h at 360 K and finnally by cooling at 12 K/h to 265 K, glass III by similarly quenching
and then aging for seven years at 295-300 K, and lastly glass IV by quenching from 390 to
298 K in less than 10 s. Their Cp' and Cp" was then measured on heating from 275 K to 393 K
at 12 K/h, and thereafter on cooling the melt in each case at 12 K/h. Cp' of the four glasses
showed a shoulder-like feature of the J-G relaxation, more prominently on cooling than on
heating with a thermal hysteresis loop for glasses I, II and III, and only its low T part was
observed for glass IV. Differences between the Cp' measured on heating of glasses II, III and
IV showed that the magnitude of their JG relaxation were different. This is evident also in the
differences between Cp" of these glasses. The method may be used to investigate local modes
of motions by dynamic calorimetry by using low heating and cooling rates with or without
annealing or aging. When poly(styrene) glass was aged at T above the JG relaxation range, in
one case reaching the equilibrium metastable state, contribution to Cp" at the low-T side of its
Cp" peak decreased, thus causing an apparent upshift of the peak. This is attributed to
relaxation of faster modes of motions in the distribution of the -relaxation time.
REFERENCES
1. Aji, D. P. B. and Johari, G. P., Kinetic-freezing and unfreezing of local-region fluctuations in a glass
structure observed by heat capacity hysteresis, J. Chem. Phys. 142, 214501 (2015).
Proc-SR-Boson-8 ORAL CONTRIBUTIONS
Oral
Glass transition in 4CFPB liquid crystal in various
pressure conditions
T. Rozwadowski1, M. Massalska-Arodź
1, M. Jasiurkowska-Delaporte
1,
K. Grzybowska2, Ż. Wojnarowska
2, M. Paluch
2
1 Institute of Nuclear Physics Polish Academy of Sciences, PL-31342 Krakow, Poland
2 Institute of Physics, University of Silesia, PL-40007 Katowice, Poland
Glass transition phenomena is still one of the most interesting problems in condensed matter
physics. Some of liquid crystals, known of their rich polymorphism show glasses of various
non isotropic phases. The subject of our studies is glassy phase with partial long range order
of molecules as the presented substance 4-cyano-3-fluorophenyl 4-butylbenzoate (4CFPB)
easily transforms to vitreous state, showing glass of nematic phase. A description of this
phenomenon in 4CFPB was determined by thermodynamic and kinetic studies using methods
like adiabatic calorimetry, differential scanning calorimetry (DSC), polarizing microscopy
(POM) and broadband dielectric spectroscopy (BDS). Additionally, molecular dynamics
investigations were performed at various pressure conditions including high pressure
experiments and measurements of confined sample in intersecting silica nanopores.
However, 4CFPB substance except isotropic phase, nematic and glass of nematic shows two
crystalline phases, which grow during sample heating. Cold crystallization phenomena is
important issue in connection to glass forming tendency. Therefore, cold crystallization
kinetics was described by microscopic, DSC and BDS methods [1].
Molecular dynamics studies have shown three molecular motions in 4CFPB. Bimodal
structural α-relaxation was found. Main process is connected with flip-flop molecular
motions, while second structural relaxation is connected with procession of molecules. The
secondary β-relaxation process, observed around and below Tg, was positively tested as
Johari-Goldstein type and ascribed to librations. Whereas, dynamics in porous matrix is more
complex, i.e. collective motions were found [2]. Based on temperature-pressure phase
diagram, pressure conditions in used size of nanopores were determined.
REFERENCES
1. Rozwadowski, T. , Massalska-Arodź, M., Kolek, Ł., Grzybowska, K., Bąk, A., Chłędowska, K., Crystal
Growth & Design. 15, 6, 2891–2900 (2015)
2. Rozwadowski, T, Massalska-Arodź, M, Krawczyk, J. , Juszynska-Gałązka, E., Liquid Crystals. 41, 8, 1073-
1079 (2014)
ORAL CONTRIBUTIONS Proc-SR-Boson-9
Invited Talk
Relationship between Global, Segmental, and Relaxation
Dynamics Studied by Broadband Dielectric Spectroscopy
Osamu Urakawa, Minoru Yamane, Shota Tomie, Tadashi Inoue
Osaka University
1-1 Machikaneyama-cho, Toyonaka, Osaka, 560-0043, JAPAN
The relationship between normal-mode, segmental-mode, and relaxation has been studied
for a model type-A polymer, poly(butylene oxide), which has a dipole componet parallel to
the chain backbone, by means of broad band dielectric spectroscopy covering the frequency
range from 2.5 m Hz to 3 GHz. Especially, the temperature (T) dependences of three
relaxation times, n (normal mode), s (segmental mode), and ( relaxation) were
compared. T dependence of s was stronger than n at low T (< 220K~Tg+20K) as well known
for some other polymers: the n/s ratio decreases by lowering the temperature approaching Tg
(thermorheological complexity).1 At intermediate temperatures (220K < T < 310K), this ratio
could be regarded as constant within experimental error. However, it has also been found that
the n/s ratio decreases systematically as the temperature increases (at T > 250K). This high
temperature complexity, which has been discussed little so far,2 was examined in detail based
on the two-step relaxation model for the segmental relaxation, in which we assumed that the
segmental motion consists of two kinetic processes: the 1st step corresponding to the local
conformation change of polymer backbone (elemental process) and the 2nd step
corresponding to the larger scale segmental motion occuring after the completion of the 1st
step. For the terminal (normal mode) relaxation, the decrease of relaxation times upon raising
temperature is mainly caused by the decrease of the inter-chain interaction. In contrast, for
the segmental motion, intra-chain rotational barrier comes to play a role at high temperatures
(T > 250K) and make the T dpendence of s diffrent from that of n. It was found that the
simple two-step relaxation model could quantitatively explain the diffrent T dependecs of s
and n. Furthermore, the elemental process (1st step) in the segmental relaxation was found to
be close to the experimentally observed for PBO.
REFERENCES
1. (a) Plazek, D.J., Temperature Dependence of Viscoelastic behavior of Polystyrene, J. Phys. Chem. 69,
3480-3487 (1965).: (b) Roland. C.M. et al., Temperature dependence of segmental and terminal relaxation
in atactic polypropylene melts., Macromolecules, 34, 6159-6160 (2001)
2. study, Phys. Rev. E. 54, 3853-3869 (1996).
Proc-SR-Boson-10 ORAL CONTRIBUTIONS
Invited Talk
Experimental evidence of relaxation anisotropy in a rigid
and planar glass forming molecule
Li-Min Wang1, Wenkang Tu
1, Sofia Valenti
2, Kia Ling Ngai
1,3, Simone
Capaccioli11,3
1State Key Lab of Metastable Materials Science and Technology, and College of Materials
Science and Engineering, Yanshan University, Qinhuangdao, Hebei, 066004 China
2Dipartimento di Fisica, Università di Pisa, I-56127 Pisa, Italy,
3CNR-IPCF, Largo B. Pontecorvo 3, I-56127, Pisa, Italy
The presence of secondary relaxations in rigid molecules has been widely known for decades,
and its fundamental importance is highlighted due to the strong connections to the
deformation and instability behaviors in glasses, in particular, to the structural -relaxation.
For a rigid molecule, it has been believed that only a single secondary relaxation is present,
which is generally identified as the JG -relaxation. However, our studies of a rigid and
planar molecule, 1-methylindole (1MID) found that the secondary relaxation does not
reproduce the rules established by rigid molecules reported in earlier studies. Also, the
dielectric measurements performed in binary mixtures of 1MID with two aromatics of weak
polarity, ethylbenzene and triphenylethylene with smaller and larger molecular sizes than
1MID, show that the secondary relaxations of 1MID in the two mixtures share the same
relaxation time and the temperature dependence as pure 1MID, independent of the mode and
degree of dilution. To get insight into the origin of the secondary relaxation in 1MID, elevated
pressure is applied to the isothermal dielectric relaxation. We found that the apparently single
secondary relaxation splits up into two relaxations, which have never been observed before in
rigid molecules. We proposed that the faster secondary relaxation in 1MID originates from in-
plane rotation, which is insensitive to elevated pressure, while the slower one comes from out-
of-plane rotation which sweeps space, sensitive to pressure. The slower secondary has a nice
connection to the structural relaxation. For the first time, anisotropic dynamics is observed in
rigid molecules with size larger than 1MID in supercooled liquids, making a novel and
important advance in the dynamics of totally rigid and planar van der Waals glass-formers.
REFERENCES
1. Li, X. Q., Wang, M., Liu, R. P., Ngai, K. L., Tian, Y. J., Wang, L.-M., and Capaccioli, S., J. Chem. Phys.
143, 104505 (2015).
2. Wang, M., Li, X. Q., Guo, Y. X., Wu, T., Liu, Y. D., Ngai, K. L., and Wang, L. -M., J. Chem. Phys. 145,
214501 (2016).
ORAL CONTRIBUTIONS Proc-SR-Boson-11
Invited Talk
On the nature of the β-process in organic glass formers
T. Körber, B. Pötzschner, D. Bock, E. A. Rössler
Universität Bayreuth, 95440 Bayreuth, Germany
The nature of the secondary or β–relaxation in glasses is still an unsolved problem. Here, we
report about experiments, applying NMR and Dielectric Spectroscopy (DS), which provide
further insight on the nature of the β-process.
1. Previous 2H NMR results showed that the β-process can be described with the isotropic
“wobbling within a cone” model. Comparing experiments of differently deuterated
toluene (-d5 vs. -d3), the β-process shows pronounced anisotropy, thus reflecting the
geometry of the molecule. Essentially a rattling around the pseudo C2-axis is involved,
implying that the dipole moment is not changing. This is at variance with the observation
of probing the β-process in DS.1
2. Investigating the β–process in neat poly(ethylene-alt-propylene) (PEP) we find, in
contrast to molecular glass formers, indications that not all polymer segments participate.
The methyl group bearing segments participate only partly in the β-process.1
3. We investigate the β–process in binary glasses over the full concentration range c by
employing DS and 2H/
31P NMR spectroscopy. This allows to probe the dynamics of each
component separately. The mixtures are made from a high-Tg component (non-
/polymeric) and a low-Tg component. The systems are characterized by two glass
transition temperatures (Tg1 and Tg2 < Tg1). The β–process, introduced by the low-Tg
component, is monitored in the low temperature regime (T < Tg2). Down to low additive
concentrations, it shows the same behavior τβ(c,T), i.e. the activation energy is essentially
not changing. As in the case of neat molecular glass formers, spatially highly hindered
motions are involved. A very similar motion can also be identified for the high-Tg
component with the same time constant and similar angular displacements. The low-Tg
component “enslaves” the molecules of the high-Tg component. At low additive
concentrations, the β-process disappears, indicating a disintegration as expected for c0
leading to “Islands of rigidity”, where the molecules are immobilized. We take these
results as an indication that the β–process (as the α–process) is cooperative in nature.2,3
REFERENCES
1. Körber et al. Macromolecules 2017, 50, 1554–1568.
2. Pötzschner et al. JCP 2017, DOI: 10.1063/1.4980084.
3. Bock et al. JCP 2013, 139, 064508.
Proc-SR-Boson-12 ORAL CONTRIBUTIONS
Invited Talk
Pressure and temperature dependence of Johari-Goldstein
relaxation dynamics in the supercooled and glassy state
Sofia Valentia, Simone Capaccioli
a, M. Shahin Thayyil
b, K. L. Ngai
a
aPhysics Dept. - Pisa University & CNR-IPCF, Largo B. Pontecorvo 3, I-56127, Pisa, Italy
bDepartment of Physics, University of Calicut, Kerala, India
The Johari-Goldstein (JG) relaxation [1], is an intermolecular secondary relaxation, which involves
motions of the whole molecule and is universally found in the amorphous state [2]. Due to its nature, it is
strongly affected by the reduction of density, related to the intermolecular potential directly dependent on
the intermolecular distance [3]. Thus the study of the molecular dynamics under pressure is worthwhile and
can be critical. This talk reports our work dealing with orientational dynamics of two polar rigid molecules,
benzonitrile and tripropyl phosphate (TPP) in mixtures with apolar solvents (polystyrene, PS) investigated
by dielectric spectroscopy over a wide range of temperature T and pressure P. The first system is very
similar to prototypical binary mixtures studied before to shed light on the JG relaxation [1, 3]. The mixture
xTPP-(1-x)PS, (with x=0.2 weight fraction) has been recently studied by Rössler and coworkers [4] at
atmospheric pressure. They called this system highly asymmetric binary glass-former due to the large
difference in glass transition temperature Tg of the components. Dielectric spectra showed in the glassy
state a fast process with Arrhenius T-dependence originating from the lower Tg component, TPP, and
interpreted as TPP confined in the rigid glassy matrix of PS, revitalizing a previous idea used for
asymmetric polymeric blends [5]. Conversely, we interpret this fast relaxation as the JG relaxation of the
TPP component in the mixture because the JG relaxation is the precursor of the -relaxation and
indispensible. The results of our study evidences that the fast relaxation in the mixtures is the
intermolecular JG process. In fact, for both systems, by applying high P under isothermal and isochronal
conditions, the structural - and the JG relaxation times are shown to be strongly interdependent in the
supercooled state, as predicted and rationalized by the Coupling Model [2]. In the glassy state both JG
relaxation shape and times can be explained according to an intermolecular energy distribution, sensitive to
the density reduction. Since the JG relaxation is more local than the -relaxation and yet depends on the
intermolecular potential, the results provide indirect insights on the glass local configuration and its P
dependence.
REFERENCES
1. Johari, G. P., Goldstein, M., Viscous liquids and the glass transition. II: secondary relaxations in glasses of rigid
molecules, J. Chem. Phys. 53, 2372-2388 (1970).
2. Ngai, K. L., Relaxation and Diffusion in Complex Systems, Springer: New York (2011).
3. Kessairi, K., Capaccioli, S., Prevosto, D., Lucchesi, M., Sharifi, S., Rolla, P. A., Interdependence of - and JG -
relaxations in glass-formers, J. Phys. Chem. B. 112, 4470-4473 (2008).
4. Kahlau, R., Bock, D., Schmidtke, B., E. Rössler, E.A., Dynamics of asymmetric binary glass formers. I. A
dielectric and nuclear magnetic resonance spectroscopy study, J. Chem. Phys. 140, 094505 (2014)
5. Lorthioir, C., Alegrıa, A., Colmenero, J., Out of equilibrium dynamics of PVME segments in miscible PS-PVME
blends, Phys. Rev. E. 68, 031805 (2003).
ORAL CONTRIBUTIONS Proc-SR-Boson-13
Invited Talk
Secondary Processes Observed in Dynamic Light Scattering
and Dielectric Spectroscopy
T. Blochowicz, J. Gabriel, F. Pabst, P. Weigl
Technical University of Darmstadt, 64289 Darmstadt, Germany
We discuss secondary relaxations, i.e., processes faster than the alpha relaxation, that appear
in the supercooled liquid regime and persist at temperatures below the glass transition. In neat
supercooled liquids consisting of rigid molecules this feature is known as Johari-Goldstein
beta process [1] and its phenomenology is well documented, mostly based on dielectric data.
However, the physical mechanisms behind that have been a matter of debate: While originally
“islands of mobility” were assumed to be responsible for the JG beta relaxation [2], NMR
measurements later on indicated small angle reorientation of all molecules as a reason [3]. In
either case molecular reorientation is involved, so that the process should be visible in a
similar manner in different reorientational correlation functions, like, e.g., those of dielectric
spectroscopy (DS) and depolarized dynamic light scattering (DDLS). However, so far it is
argued, that the beta relaxation is not observed in DDLS at all [4]. In the present contribution
we look for the DDLS signature of secondary relaxations in glass formers and give a
quantitative comparison of their appearance in DDLS and in dielectric spectroscopy. Because
both methods detect molecular reorientation via correlation functions of different Legendre
polynomials, we also discuss possible implications of our findings for the motional
mechanism behind the beta relaxation.
REFERENCES
1. Johari, G.P., Goldstein, M, Viscous liquids and the glass transition II: Secondary relaxations in glasses of
rigid molecules, J. Chem. Phys. 53, 2372-2388 (1970).
2. Goldstein, M., Viscous Liquids and the Glass Transition: A Potential Energy Barrier Picture, J. Chem. Phys.
51, 3728 (1969)
3. Vogel, M., Rössler, E., Slow β process in simple organic glass formers studied by one and two-dimensional
2H nuclear magnetic resonance, J. Chem. Phys., 114, 5802 (2001)
4. Brodin, A., Bergman, R., Mattsson, J., Rössler, E.A., Light scattering and dielectric manifestations of
secondary relaxations in molecular glassformers, Eur. Phys. J. B, 36, 349 (2003)
Proc-SR-Boson-14 ORAL CONTRIBUTIONS
Invited Talk
Viscoelastic dynamics and energy dissipation in glasses at
the atomic scale
Tanguy Damart, David Rodney
Institut Lumière Matière, CNRS UMR 5306, Université Claude Bernard Lyon 1
10 rue Ada Byron, VILLEURBANNE 69622 FRANCE
Dissipation of the mechanical energy of a wave propagating in a glass strongly depends on
the frequency. We will show how both the very low (< MHz) and very high (> THz)
frequency regimes can be modeled at the atomic scale in silica using two different
approaches. At low frequencies, dissipation is controlled by the thermally-activation
relaxation of local bistable regions, two-level systems, whose properties can be measured by
sampling the glass potential energy landscape. By way of contrast, at high frequencies, the
glass dynamics become harmonic and can be analyzed using a normal mode analysis. We will
see that in silica, which forms tetrahedral networks without coordination defects, dissipation
and viscoelastic effects at both low and high frequencies are due to the vibration and
reorientation of the Si-O-Si bonds.
REFERENCE
1. Damart, T., Tanguy, A., Rodney, D. ‘Theory of harmonic dissipation in glasses’, Physical Review B. 95,
054203 (2017).
ORAL CONTRIBUTIONS Proc-SR-Boson-15
Invited Talk
Sub-Arrhenius dynamics: Results from a
dissipative particle dynamics model
Michael L. Greenfield1 Jeppe C. Dyre
2, Jesper S. Hansen
2
1Department of Chemistry, The University of Rhode Island, USA
2“Glass and Time”, IMFUFA, Department of Sciences and Environment,
Roskilde University, Denmark
Results for the dynamical properties of a mesoscopic model based on dissipative particle
dynamics are shown. The model can include, for example, translational, end-to-end, and
rotational degrees of freedom, thus, it provides an excellent platform to study complex
systems with multiple characteristic relaxation times1. The model also captures sub-Arrhenius
behavior; both for single particle properties like the rotational correlation function and self-
diffusivity and for collective properties like the shear viscosity2. The underlying physical
mechanisms behind the sub-Arrhenius behavior is discussed, in particular in the framework of
generalized hydrodynamics3,4
where the cooperativity is quantified through spatial correlation
lengths5,6
in both single particle and collective dynamical properties.
REFERENCE
1. Greenfield, M.L., Dyre, J.C., Hansen, J.S., “The ROSE model: Mesoscopic model of polymer modified
bitumen”, in prep.
2. Greenfield, M.L., Dyre, J.C., Hansen, J.S., “Sub-Arrhenius dynamics in a dissipative particle dynamics
model”, in prep.
3. Kadanoff, L.P., Martin, P.C., “Hydrodynamic Equations and Correlation Functions”, Ann. Phys. 24, 219
(1963).
4. Hansen, J. S., Daivis, P. J., Dyre, J. C., Todd, B. D., Bruus, H., “ Generalized extended Navier-Stokes
theory: Correlations in molecular fluids with intrinsic angular momentum”, J. Chem. Phys. 138, 034503
(2013).
5. Furukawa, A., Tanaka, H., “Nonlocal Nature of the Viscous Transport in Supercooled Liquids: Complex
Fluid Approach to Supercooled Liquids”, Phys. Rev. Lett., 103, 135703 (2009).
6. Hansen, J.S., Daivis, P.J., Travis, K.P., Todd, B.D., “Parameterization of the nonlocal viscosity kernel for an
atomic fluid”, Phys. Rev. E, 76, 041121 (2007).
Proc-SR-Boson-16 ORAL CONTRIBUTIONS
Invited Talk
Studying mutarotation of saccharides in the close vicinity
of the glass transition temperature. Interplay between
physics and chemistry
K. Kaminskia,b
, K. Wolnica,a,b
E. Kaminskac ,M. Tarnacka,
a,b R. Wrzalik
a,b
and M. Palucha,b
aSilesian Center for Education and Interdisciplinary Research, 75 Pulku Piechoty 1a, 41-500
Chorzow, Poland
bA. Chelkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007
Katowice, Poland
cDepartment of Pharmacognosy and Phytochemistry, Medical University of Silesia in
Katowice, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, ul.
Jagiellonska 4, 41-200 Sosnowiec, Poland
Comprehensive studies on the mutarotation in saccharides around the glass transition
temperature were carried out with the use of FTIR, Raman and Broadband Dielectric
Spectroscopy. We found a lot of unexpected results involving sigmoidal character of the
kinetic curves, pretty high activation barrier for this process with respect to the current state of
the art. Moreover our very recent results indicate that mutarotation in the supercooled phase
can not be described by single activation barrier. We observe significant change in
temperature dependence of the rate constant at the glass transition and at the crossover
temperature. In addition we tested a relationship between constant rates, structural relaxation
times and dc conductivity and found that above the Tg there is a decoupling between both
quantities. These results provide new insight on the close relationship between physics of
condensed matter and chemistry of this canonical reaction.
ORAL CONTRIBUTIONS Proc-SR-Boson-17
Invited talk
Novel non-Debye Relaxation Process and New Physical
Insight form the Dielectric Spectra of Glass Forming
Alcohols
G. Govindaraj
Department of Physics, School of Physical, Chemical and Applied Sciences, Pondicherry
University, Puducherry 605 014, India
The physical ideas underlying in the interaction of dipoles and their relaxation in the dielectric and ac
conductivity spectra with results based on time-honored models of Cole-Cole, Cole-Davidson, Havriliak-
Negami, Kohlrausch-Williams-Watts, Jonscher, Ngai and different barrier hopping model are still debated
and do not offer satisfactory interpretation. In our work (G. Govindaraj, AIP Conference Proceedings,
1731, 070025 (1)-(3) (2016); N.S.K. Kumar, T.S. Shahid, G. Govindaraj, Physica B, 488, 99–107 (2016)),
the dielectric loss spectra is shown to be sum of n number of subunits or subgroups or correlated clusters of
molecular motion with differing time scales of relaxations, where (0)n is Debye type dipole moment and
n=1, 2, 3… Each subunit and its time scale of motion is statistically independent and discriminated by
Debye and its non-Debye relaxation process. For each subunit dipole moment (0)n motion, unique
intermolecular interaction triggered non-Debye dipole moment ±()n=((1-d)0)n and ensuing dual dipole
moment (±)n=(0±(1-d)0)n is proposed in terms of Debye type dipole moment (0) to describe the non-
Debye relaxation process, where (+)n=((2-d)0)n, ()n=(d0)n and (d)n is an exponent 0<(d)n<1, and
signifies intermolecular interaction strength with a redistribution and conservation of Debye type dielectric
loss and moment. During the molecular motion, instantaneous transfer of dipole moment 0 is not possible
due to intermolecular dipole-dipole interaction and hence dipole ± is created, where the N number 0
dipole becomes N/2 pairs of (±). The complex dielectric and relaxation functions are obtained for (+)n
and ()n for each subunit motion for the dipole. For the systems having dielectric (‘free dipole’) and
conductive (‘pinned dipole’) processes, total dielectric function is obtained as:
𝜖𝐺𝐺∗ (𝜔) = ∑ ([𝜖𝑑
∗ (𝜔)](𝝁±)𝑑
𝑛𝑚=1 )𝑚 + [𝜖𝑐
∗(𝜔)](𝝁±)𝑐,
where the suffix d and c represents dielectric and conductive dipole processes contributions,
[𝜖𝑑∗ (𝜔)](𝝁−)𝑑
= 𝜖∞ + ∆𝜖/(1 + 𝑖𝛼𝑑(𝜔𝜏𝑑)𝛼𝑑) ; [𝜖𝑑∗ (𝜔)](𝝁+)𝑑
= ∆𝜖/(1 + 𝑖𝛼𝑑(𝜔𝜏𝑑)2−𝛼𝑑),
[𝜖𝑐∗(𝜔)](𝝁−)𝑐
= [𝜎𝑐∗(𝜔)](𝑮−)𝑐
/(𝑖𝜔𝜖0) ; [𝜖𝑐∗(𝜔)](𝑮+)𝑐
= [𝜎𝑐∗(𝜔)](𝝁+)𝑐
/(𝑖𝜔𝜖0),
[𝜎𝑐∗(𝜔)](𝝁−)𝑐
= 𝜎(0)(1 + 𝑖𝛼𝑐(𝜔𝜏𝑐)𝛼𝑐); [𝜎𝑐∗(𝜔)](𝝁+)𝑐
= 𝜎(0)(1 + 𝑖𝛼𝑐(𝜔𝜏𝑐)2−𝛼𝑐).
In the light of these results, new physical insight emerges for , , , relaxations and excess wing in the
glass forming alcohols (and other dielectric systems) and shows an excellent agreement with dielectric
spectra. These results will be presented and discussed.
Theor-Simul-1 ORAL CONTRIBUTIONS
Invited Talk
Effective Theories for Supercooled liquids
Tommaso Rizzo
Institute for Complex Systems, National Research Council (ISC-CNR),
UOS Sapienza, Piazzale A. Moro 5, 00185 Roma, Italy
Department of Physics, University Sapienza, Piazzale Aldo Moro 5, 00185 Rome (IT).
Effective theories are typically introduced under the assumption that, on large length scales, a
system can be described in terms of a small set of coupling constants rather than the full set of
microscopic interactions. General considerations suggest that this assumption may be justified
if the correlation length becomes large with respect to the microscopic length and indeed
effective theories appear naturally in the context of critical phenomena. On the contrary if
there is no genuine critical point there is no guarantee that an effective theory is appropriate
for a given microscopic model, given that their relationship is based only on symmetry
considerations.
This problem is pressing in the context of supercooled liquids because it has been recently
shown that a dynamical effective theory, introduced as usual following symmetry arguments
[1], displays many features that are commonly associated to the glass crossover observed in
many supercooled liquids. These include well established properties like the crossover from
power-law to exponential relaxation and dynamical heterogeneities, but also more
controversial features like the notion of a decreasing dynamical correlation length [2].
The question is weather this is just a coincidence or instead the connection between the
microscopic models and the effective theory can be established beyond the level of curve
fitting. A partial answer to this problems comes from the existence of a numbers of academic
microscopic liquid models that are exactly described by the dynamical effective theory: this
implies that, at worst, it can be viewed as a toy model of supercooled liquids. For generic
models I will discuss some tests and condition that one can perform in order to address the
problem in a systematic way.
REFERENCES
1. Rizzo, T., Long-wavelength fluctuations lead to a model of the glass crossover, EPL. 106, 56003 (2014),
Dynamical Landau Theory of the Glass Crossover, Phys. Rev. B 94, 014202 (2016)
2. Rizzo, T., Voigtmann, T., Qualitative Features at the Glass Crossover, EPL. 111, 56008 (2015), On The
Nature of the Glass Crossover, arXiv:1504.06263
ORAL CONTRIBUTIONS Theor-Simul-2
Invited Talk
A simple theory for the dynamics of mean-field-like models
of glass-forming fluids
Grzegorz Szamel
Department of Chemistry, Colorado State University, Fort Collins, CO 80523, USA
We propose a simple theory for the dynamics of model glass-forming fluids, which should be
solvable using a mean-field-like approach. The theory is based on transparent physical
assumptions, which can be tested in computer simulations. The theory predicts an ergodicity-
breaking transition that is identical to the so-called dynamic transition predicted within the
replica approach. Thus, it can provide the missing dynamic component of the random first
order transition framework. In the large-dimensional limit the theory reproduces the result of
a recent exact calculation of Maimbourg et al. [PRL 116, 015902 (2016)]. Our approach
provides an alternative, physically motivated derivation of this result.
Theor-Simul-3 ORAL CONTRIBUTIONS
Invited Talk
Cooperative Motion and Structural Relaxation in Glass-
Forming Materials
Jack F. Douglasa and Beatriz Betancourt
a, Francis Starr
b
aNational Institute of Standards and Technology, Materials Science
and Engineering Division, Gaithersburg, MD 20899 USA
bDepartment of Physics, Wesleyan University, Middletown, CT 06459
We investigate collective motion and relaxation in model polymeric glass-forming liquids by
molecular dynamics simulation to quantify the nature of cooperative motion in these liquids
and to understand the significance of cooperative particle exchange motion for understanding
relaxation properties of glass-forming liquids generally. We find that relaxation occurs as
multi-stage process involving cooperative molecular motion. First, there is a ‘fast’ or -
relaxation process dominated by the inertial motion of the molecules, followed by a longer
time -relaxation process involving large scale diffusive motion. Our molecular dynamics
simulations indicate that as the collective motion of the -relaxation regime becomes
progressively suppressed upon approaching Tg, material relaxation requires larger scale
collective motion involving molecular diffusion, explaining the emergence of the -relaxation
regime. In both relaxation regimes, relaxation occurs through a string-like collective particle
exchange motion having a common string-like geometrical form and quantitative
relationships are derived relating the length of the ‘stringlets’ found in the -relaxation regime
to the ‘strings’ characterizing collective motion at long times associated with the thermally
activated diffusive motion. Based on this physical picture, we find that the -relaxation time
data for a wide range of simulated glass-forming liquids can be described by an extension of
the Adam-Gibbs model in which the free energy of activation (including the entropy of
activation neglected by AG) is proportional to the average length L of string-like particle
exchange clusters. This same type of collective motion arises in the grain boundaries of
polycrystalline materials, the interfaces of nanoparticles, superheated crystals, and in
biological materials such lipid membranes and proteins so that string-like collective motion is
evidently a common feature of strongly-interacting condensed matter.
ORAL CONTRIBUTIONS Theor-Simul-4
Invited Talk
The role of pair correlation function in the dynamical
transition predicted by the mode coupling theory
Sarika Maitra Bhattacharyya
Polymer Science and Engineering Division, CSIR-National Chemical Laboratory, Pune,
411008
In a recent study we have shown that the pair configurational entropy, Sc2 , vanishes at the
mode coupling transition temperature, Tc [1] . Pair configurational entropy is a
thermodynamic quantity, which primarily requires information of the two body radial
distribution function (rdf). The Fourier transform of the rdf, the structure factor, when fed into
the microscopic mode coupling theory (MCT), predicts the transition at a much higher
temperature. In order to investigate if indeed any information of the transition temperature is
embedded in the structure of the liquid and if so which one it predicts, we propose a new
model calculation. Starting from the Fokker-Planck (FP) equation and using the key ideas of
dynamic density-functional theory (DDFT), we show that the dynamics depends on the pair
structure of the liquid. The dynamics in turn predicts a transition temperature which is similar
to Tc . Thus we show that the information of the MCT transition temperature, Tc , is
embedded in the pair structure of the system [2].
REFERENCES
1. Banerjee, A., Sengupta, S., Sastry, S., and Bhattacharyya, S. M., Phys. Rev. Lett., 113, 225701 (2014).
2. Nandi, M. K., Banerjee, A., Dasgupta, C., and Bhattacharyya, S. M., (to be submitted).
Theor-Simul-5 ORAL CONTRIBUTIONS
Invited Talk
Understanding Soft Modes in Simple Glass models
Silvio Franz (1) G. Parisi (2), P. Urbani (3), F. Zamponi (4)
(1) LPTMS, CNRS, Univ. Paris-Sud, Universite Paris-Saclay, 91405 Orsay, France
(2) Dipartimento di Fisica, Sapienza Università di Roma I-00185 Rome, Italy
(3) IPHT CEA SACLAY France
(4) LPTENS CNRS Paris France
I will show how a well-known neural network model —the perceptron— provides a simple
solvable model of glassy behavior and jamming. The glassy minima of the energy function of
this model can be studied in full analytic detail. This allows the identification of two kind of
soft modes the first ones associated to the existence a marginal glass phase and a hierarchical
structure of the energy landscape, the second ones associated to isostaticity and marginality of
jamming. These results highlight the universality of the spectrum of normal modes in
disordered systems, and open the way toward a detailed analytical understanding of the
vibrational spectrum of low-temperature glasses.
REFERENCES
1. Parisi, S. F. G., “The Simplest Model of Jamming” J. Phys. A: Math. Theor. 49 (2016) 145001
2. Parisi, S. F. G., Urbani, P., and Zamponi, F., “Universal spectrum of normal modes in low- temperature
glasses, PNAS. 47 14539–14544 (2015)
ORAL CONTRIBUTIONS Theor-Simul-6
Invited Talk
Mode Coupling Theory of Active Brownian Particles
Thomas Voigtmann , Alexander Liluashvili, Jonathan Ónody
Institute of Materials Physics in Space, German Aerospace Center (DLR), Cologne, Germany
Heinrich-Heine-Universität Düsseldorf, Germany
We discuss a dense system of active Brownian particles (ABP) as a simple model system to
study the collective behavior of microswimmers. The particles undergo Brownian dynamics
modified by an active driving along an internal, randomly reorienting direction. The non-
equilibrium dynamics depends on two relevant parameters: the driving velocity v0 and the
rotational diffusion coefficient Dr. The latter is varied over a wide range to mimic the effects
of persistence in the swimming direction.
Using the integration-through transients (ITT) formalism and a suitably extended mode-
coupling theory of the glass transition (MCT), we study how the glassy dynamics of two-
dimensional Brownian hard disks is modified by activity. We discuss under which
circumstances the dynamics can be understood in terms of an effective enhanced diffusivity
(set by the Péclet number v02/Dr), and when this mapping fails. The ITT formalism allows to
derive generalized Green-Kubo relations for steady-state averages, e.g., for the activity-
dependent nonequilibrium static structure factor or for the density-dependent average swim
speed. We discuss how MCT can be used to provide microscopic predictions for these
quantities that appear in coarse-grained theories of active matter.
Theor-Simul-7 ORAL CONTRIBUTIONS
Invited Talk
A renormalized nonlinear equation near the glass transition
based on time-convolutionless mode-coupling theory
Michio Tokuyama
Institute of Multidisciplinary Research for Advanced Materials, Tohoku University,
Sendai 980-8577, Japan
The main purpose of the present paper is to investigate based on the time-convolutionless
mode-coupling theory (TMCT) recently proposed by the present author1,2
how the static
structure factor S(k) contained in the ideal mode-coupling memory function (q,t) plays an
important role near the glass transition. A simplified model applied for (q,t) is extended to
a renormalized one by replacing a quadratic nonlinear term f(qm,t)2 by a higher-order
nonlinear term f(qm,t)2+ where is a renormalized exponent to be determined, qm a first peak
position of S(q) and f(q,t) the collective-intermediate scattering function. By introducing the
cumulant function K(q,t) by f(q,t)=exp[-K(q,t)], a second-order nonlinear differential equation
for K(qm,t) is then obtained2. In order to find the numerical solutions are compared with the
simulation results performed in two types of liquids, (F) fragile liquids and (S) strong liquids,
where all unknown quantities contained in the equation, such as a collective-diffusion
coefficient Dc(qm), are given from the simulation results. Thus, is found as
=au+b for fragile liquids,
=2au+c for strong liquids,
where a≈0.70, b≈1.312, and c≈2.262. Here u is a universal parameter given by u=log(t)=-
log(Dc), where t is a -relaxation time. This result suggests that if u has the same value in
different systems of each type, (F) or (S), therefore, their dynamics completely coincides with
each other. Thus, it is shown that there exists a universality in the dynamics of each type of
liquid, (F) or (S) but not between them2,3
. The details will be discussed in the paper.
REFERENCES
1. Tokuyama, M., Statistical-mechanical theory of nonlinear density fluctuations near the glass transition,
Physica A 395, 31-47 (2014).
2. Tokuyama, M., Phenomenological theory of a renormalized simplified model based on time-convolutionless
mode-coupling theory near the glass transition, Physica A 465, 229-247 (2017).
3. Tokuyama, M., Enda, S., Kawamura, J., A novel difference between strong liquids and fragile liquids in
their dynamics near the glass transition, Physica A 442, 1-13 (2016).
ORAL CONTRIBUTIONS Theor-Simul-8
Invited Talk
Isomorphs in liquids and glasses: Role of the potential
Nicholas P. Bailey*
Glass and Time, Dept. of Science and Environment, Roskilde University, Roskilde, Denmark
Isomorphic scaling is a kind of scale invariance only recently recognized in condensed matter
[1]. Its consequences include invariance of equilibrium structural and dynamic properties
along isomorphs, which are curves in the density-temperature phase diagram [2]. They exist
for a certain class of "R simple" liquids and can be identified from the fluctuations in potential
energy and virial which give their logarithmic slope γ, known as the scaling exponent in the
context of density scaling of dynamics. Isomorph invariance applies not just to equilibrium
properties, but also in non-Newtonian viscosity [4], and in deformation of the glass. I will
focus particularly on the connection between the intermolecular potential and the scaling
exponent γ. For general pair potentials, assuming isomorphs exist, there is a connection
between γ and the derivatives of the potential evaluated at the average interparticle spacing,
which can also predict γ's density dependence [5]. For comparison with experimental data it is
important to understand how molecular structure, in particular the presence of bonds, affects
γ. For example rigid bonds tend to increase γ compared to the system with no bonds
removed,.and can also cause to γ to increase, rather than decrease, as a function of density.
Finally, metallic systems involving many-body interactions are also of interest due to the
increasing importance of metallic glasses. Recent density functional theory (DFT)
calculations confirm the claim that metals fall in the class of R simple systems [5]. I will show
that within the effective medium theory description of metallic bonding [6], which gives
results consistent with DFT, this can be traced to the exponential pair interaction.
REFERENCES
1. Dyre, J. C., Hidden Scale Invariance in Condensed Matter, J. Phys. Chem. B, 118, 10007 (2014)
2. Gnan, N., Schrøder, T. B., Pedersen, U. R., Bailey, N. P., and Dyre, J. C., Pressure-energy correlations in
liquids. IV. 'Isomorphs' in liquid state diagrams. J. Chem. Phys., 131, 234504 (2009)
3. Bailey, N. P., Pedersen, U. R., Gnan, N., Schrøder, T. B., and Dyre, J. C., Pressure-energy correlations in
liquids. II. Analysis and consequences.
4. Separdar, L., Bailey, N. P., Schrøder, T. B., Davatolhagh, S., and Dyre, J. C., Isomorph invariance of
Couette shear flows simulated by the SLLOD equations of motion, J. Chem. Phys., 138, 154505 (2013)
5. Bailey, N. P., Bøhling, L., Veldhorst, A. A., Schrøder, T. B., and Dyre, J. C., Statistical mechanics of
Roskilde liquids: Configurational adiabats, specific heat contours, and density dependence of the scaling
exponent, J. Chem. Phys., 139, 184506 (2013)
6. Hummel, F., Kresse, G., Dyre, J. C., and Pedersen, U. R., Hidden Scale Invariance of Metals, Phys. Rev. B,
92, 174116 (2015)
7. Jacobsen, K. W., Stoltze, P., and Nørskov, J. K., A semi-empirical effective medium theory for metals and
alloys, Surf. Sci., 366, 394 (1996).
Theor-Simul-9 ORAL CONTRIBUTIONS
Invited Talk
Glassy dynamics as a consequence of the equilibrium liquid
to solid transition
Zohar Nussinov
Washington University in Saint Louis
We will review the underpinning of the micro-canonical ensemble and the more refined
"Eigenstate Thermalization Hypothesis". We will then find and apply a simple corollary of
these to analyze the evolution of a liquid upon supercooling to form a structural glass. Simple
theoretical considerations lead to predictions for general properties of supercooled liquids.
Amongst other things, a collapse of the viscosity of glass formers is predicted from this
theory. This collapse indeed occurs over 16 decades of relaxation times for all known types of
glass formers. New testable predictions are made
REFERENCES
1. Nussinov, Z., “A one parameter fir for glassy dynamics as a quantum corollary of the liquid to solid
transition”, Philosophical Magazine. 97, 1509 (2017).
2. Weingartner N. B, Pueblo C., Nogueira F. S., Kelton K.F., and Nussinov, Z. “A Phase Space Approach to
Supercooled Liquids and a Universal Collapse of Their Viscosity” , Frontiers in Materials. 3, 50 (2016).
ORAL CONTRIBUTIONS Theor-Simul-10
Invited Talk
Molecular Dynamics Simulations of Structure and Mobility
in Polyimide-based Nanocomposites
Sergey Lyulin
Institute of Macromolecular Compounds, Bolshoj pr. 31, St. Petersburg, 199004, Russia
In the present simulations the structural and dynamic properties of polymer nanocomposites
based on thermoplastic polyimides filled with different types of carbon nanoparticles have
been studied by means of fully-atomistic Molecular Dynamics (MD) simulations on micro-
second time scale. Reinforcement of thermoplastic polymers by carbon nanoparticles is very
important in the case of crystallizable polymers when nanoparticles may induce
crystallization. Three different types of carbon nanoparticles have been considered: fullerenes,
carbon nanotubes (CNT), and graphene with modified or non-modified surface. It was shown
that pristine CNT and graphene may induce structural ordering of crystallizable polyimide
due to pi-pi interactions. Such structural ordering leads to the essential anisotropy of polymer
mechanical properties near nanoparticle surface and increase of averaged Young modulus [1].
Local orientational mobility depends significantly on the chemical structure of polymers and
related with thermal and mechanical properties in glassy state [2, 3]. Fullerene diffusion in
polyimide melts may serve for estimation of viscosity properties of new polymers before
synthesis [4].
The study was carried out with the financial support from the Ministry of Education and
Science of the Russian Federation under the Contract no. 14.Z50.31.0002 (megagrant of the
Government of the Russian Federation according to the Resolution no. 220 of April 9, 2010).
REFERENCES
1. Falkovich, S., Nazarychev, V., Larin, S., Kenny, J., Lyulin, S., Mechanical Properties of a Polymer
at the Interface Structurally Ordered by Graphene. J. Phys. Chem. C. 120, 6771−6777 (2016).
2. Nazarychev, V., Lyulin, A., Larin, S., Gurtovenko, A., Kenny, J., Lyulin, S., Molecular dynamics
simulations of uniaxial deformation of thermoplastic polyimides, Soft Matter. 12, 3972-3981
(2016).
3. Nazarychev, V., Lyulin, A., Larin, S., Gofman, I., Kenny, J., Lyulin, S., Correlation between the
High-Temperature Local Mobility of Heterocyclic Polyimides and Their Mechanical Properties,
Macromolecules. 49, 6700-6710 (2016).
4. Volgin, I., Larin, S., Abad, E., Lyulin, S., Molecular Dynamics Simulations of Fullerene Diffusion
in Polymer Melts, Macromolecules. 50, 2207−2218 (2017).
Theor-Simul-11 ORAL CONTRIBUTIONS
Invited Talk
Rotational glass transitions and jamming in a large
dimensional limit
Hajime Yoshino
Cybermedia Center & Department of Physics, Osaka University,
Machikaneyama 1-32, Toyonaka, Osaka 560-0043, Japan
We study glass transitions and jamming of supercooled vectorial spin systems without
quenched disorder in a large dimensional limit [1]. Our theory provides a unified mean-field
theoretical framework for glass transitions of rotational degree of freedoms such as color
angles in the continuous coloring of graphs, vector spins of geometrically frustrated magnets,
directors of Janus particles and ellipsoids. The rotational glass transitions accompany various
types of replica symmetry breaking. In the case of repulsive hardcore interactions in the spin
space, the criticality of the jamming transition becomes the same as that of hardspheres [2].
Glassy systems carrying ’spins’ representing rotational degree of freedoms. a) Continuous
coloring of a graph: The color angle 0 < θ < 2π, as in the standard HSV color map, can be
represented by a XY spin, i.e. a vector with M = 2 component (green arrow). The example
shown here is a solution to the requirement that color angle on adjacent vertexes must be
greater than or equal to 2π/3. b) Geometrically frustrated magnets: vectorial spins (green
arrows) with antiferromagnetic couplings on adjacent vertexes on corner sharing triangles
(e.g. kagome lattice), tetrahedras (e.g. pylochlore lattice). The ground states are highly
degenerate due to the loose connectivity of the lattices. c) Janus particles: hardspheres with
attractive (white) and repulsive (blue) surfaces whose orientations are represented by the
directors (green arrows).
REFERENCES
1. Yoshino, H., arXiv: 1704.01216.
2. Charbonneau, P., Kurchan, J., Parisi, G., Urbani, P., and Zamponi, F., Nature communications. 5 (2014).
ORAL CONTRIBUTIONS Theor-Simul-12
Invited Talk
Nonlocal and nonlinear elasticity near jamming
Brian P. Tighe
TU Delft Leeghwaterstraat 39, 2628 CB Delft The Netherlands
When determining the constitutive relation of an elastic solid via rheometry or simulations,
one typically takes great care to apply slow, weak, and spatially uniform deformations. But in
practice, none of these conditions need apply. I will discuss what happens to soft amorphous
solids as strain rates, strain amplitudes and strain gradients are gradually increased, causing
viscous, nonlinear, and nonlocal effects, respectively, to play an important role. For
concreteness, I will focus on the case of soft sphere packings near the jamming transition,
which form fragile solids when subjected to a confining pressure, and which serve as a
numerical model for foams and emulsions. Key questions are then: on what time scale are
viscous effects significant? At what strain amplitude are nonlinearities important? And what
length scale governs the appearance of nonlocal effects? In answering these questions I will
show that elasticity near in marginal solids depends crucially, and critically, on the distance to
jamming, and I will present novel constitutive relations that go beyond the case of local,
linear, elastic response. 1,2
REFERENCES
1. Boschan, J., Vågberg, D., and Tighe, B.P., Soft Matter 12, 5450 (2016)
2. Baumgarten, K., Vågberg, D., and Tighe, B.P., Phys. Rev. Lett. 118, 098001 (2017)
Theor-Simul-13 ORAL CONTRIBUTIONS
Invited Talk
Probing fluctuations in glass formers through biasing and
pinning in trajectories and configurations
Juan P. Garrahan
School of Physics and Astronomy and
Centre for the Mathematics and Theoretical Physics of Quantum Non-equilibrium Systems,
University of Nottingham, Nottingham NG7 2RD, UK
Many of the generic features of the dynamics of glass formers can be traced back to the
proximity to singularities predicted theoretically, which are nevertheless not directly
accessible in experiments. The three notable examples of these are: the first-order in
trajectory space between active and inactive dynamics phases [1], the first-order
thermodynamic transition that occurs when two systems are finitely coupled [2,3], and the
ideal glass transition that would occur under random pinning [4]. I will consider possible
connections between these different forms of dynamic and thermodynamic biasing, and
manifestations of these inaccessible transitions in terms of mesoscopic fluctuations associated
with pre-transition effects. I will discuss the phenomenological implications of these results.
[1] L.O. Hedges, R.L. Jack, J.P. Garrahan and D. Chandler, Science 323, 1309 (2009).
[2] S. Franz and G. Parisi, J. Stat. Mech. P11012 (2013).
[3] R.L. Jack and J.P. Garrahan, Phys. Rev. Lett. 116, 055702 (2016).
[4] C. Cammarota and G. Biroli, Proc. Natl. Acad. Sci. U.S.A. 109, 8850 (2012).
ORAL CONTRIBUTIONS Theor-Simul-14
Invited Talk
Voronoi Liquids and Glasses
C. Ruscher, J. Baschnagel, A.N. Semenov, J. Farago
Institut Charles Sadron – CNRS – Université de Strasbourg
Voronoi tessallations are customarily used in physics as an elaborate tool to analyse structural
properties of disordered condensed phases : In the context of glass-forming liquids, it led for
instance to the concept of so-called locally preferred structures as a local structural signature
of dynamical heterogeneities [1]. Recently, we devised a new theoretical model of fluid,
dubbed Voronoi fluid [2,3], where the Voronoi tessellations are given an active role, the
forces being explicitly defined in terms of the tessellation of the configurations. In
comparison to ordinary, pair force based, fluid models, this fluid possesses a number of
original traits, which will be reviewed here : intrinsic polydispersity, anomalous
thermodynamic scaling, absence of bare excluded volume, etc…
This study has been recently extended to a binary version of the Voronoi fluid, using the
radical Laguerre-Voronoi tessellations to bypass the crystallization transition. We present
here the results of this study, with a view to a comparison of its glass transition with more
widespread glass-forming models of fluids. To what extent and how the very peculiar features
of the Voronoi fluids influence or modify the known signatures of the glass transition are the
main questions addressed in this study.
REFERENCES
1. Coslovich, D., Phys. Rev. E. 83, 051505 (2011).
2. Ruscher, C., Baschnagel, J., Farago, J., EPL. 112 66003 (2015).
3. Ruscher, C., Semenov, A. N., Baschnagel, J., and Farago, J., J. Chem Phys. 146, 144502 (2017)
Theor-Simul-15 ORAL CONTRIBUTIONS
Invited Talk
Anisotropic thermal conductivity in glassy TPD films
Riccardo Dettori and Luciano Colombo
Department of Physics, University of Cagliari
Cittadella Universitaria, I-09042 Monserrato (Ca), ITALY
We present and discuss state-of-the-art atomistic simulations addressed to investigate the
thermal transport properties of deposited glassy TPD films. In particular, we provide evidence
about the anisotropy of heat transfer, when comparing both different in-plane directions and
in-plane vs. normal-to-plane directions. We quantitatively correlate such anisotropic transport
behaviour to an inherent molecular property, namely the axial structure of the TPD molecule.
Temperature effects are as well investigated, further confirming our picture. The simulation
results are in good qualitative agreement with recent measurements [1].
REFERENCES
1. Rodriguez-Viejo, J. et al., private communication (2017).
ORAL CONTRIBUTIONS Theor-Simul-16
Oral
Low-energy excitations in glassy solids
Edan Lerner
Institute for Theoretical Physics, University of Amsterdam, Netherlands
The disordered microstructure of glassy solids gives rise to a population of soft excitations
whose density determines various mechanical, dynamic and thermodynamic properties of the
glass. Despite their fundamental importance, much is unknown about the abundance of these
‘glassy modes’, their spatial structure and degree of universality. In my talk I will present
results from numerical simulations of several model glasses [1] showing that the low-
frequency tail of the density of states follows D(ω)∼ω4 up to the vicinity of the longest
wavelength shear-wave frequency. I will discuss the localization properties of soft glassy
modes, and the effects of preparation protocol, internal stresses, and dimensionality on their
statistics. Finally, I will move away from the harmonic regime and introduce an alternative
definition of low-energy excitations in glasses that properly accounts for anharmonicities of
the potential energy [2,3]. I will show that these nonlinear excitations, unlike harmonic glassy
modes, do not hybridize with extended excitations. Nonlinear excitations therefore coexist
with plane-waves in phononic frequency bands, making them good candidates as the
fundamental low-energy excitations in glassy solids.
REFERENCES
1. Lerner, E., Düring, G., and Bouchbinder, E., Statistics and properties of low-frequency vibrational modes
in structural glasses, Phys. Rev. Lett. 117, 035501 (2016).
2. Gartner, L., and Lerner, E., Nonlinear plastic modes in disordered solids, Phys. Rev. E 93, 011001(R)
(2016).
3. Gartner, L., and Lerner, E., Nonlinear modes disentangle glassy and Goldstone modes in structural glasses,
SciPost Phys. 1, 016 (2016).
Theor-Simul-17 ORAL CONTRIBUTIONS
Oral
Ergodicity Breaking in a glassy soft sphere system at small
temperatures
Michael Schmiedeberg and Moumita Maiti
Institute of Theoretical Physics 1, Friedrich-Alexander University Erlangen-Nürnberg,
Staudtstr. 7, 91058 Erlangen, Germany
The dynamics of many particulate systems dramatically slows down if the density is increased
or the temperature is decreased. Due to the slowdown the systems become effectively non-
ergodic at the timescales of observation which usually is referred to as glass transition. While
such an ergodicity breaking transition at non-zero temperature seems to be hard to access for
experimental, theoretical, or simulation studies, jamming at zero temperature has been
explored in great detail. It is a widely discussed question whether this athermal jamming
transition is related to the glass transition. Motivated by the exploration of the energy
landscape that has been successfully used to describe athermal jamming, we introduce a new
method to access thermal jamming at small but non-zero temperatures. While in case of
athermal jamming for a given random starting configuration only the local energy minimum
is determined, we in addition allow the thermally excited crossing of energy barriers
corresponding to steps known from models that describe ageing in the glass. Interestingly, we
observe that the effective ergodicity breaking in the limit of small but non-zero temperatures
occurs at a value that is below the transition density of athermal jamming. This confirms
recent computer simulation studies where athermal jamming occurs deep inside the glass
phase. In addition, with our method we determined the critical behavior of the ergodicity
breaking transition and show that it is in the same universality class as a directed percolation
transition in time. Therefore, our new method not only makes the ergodicity breaking easily
accessible and helps to reveal its universality class, but also shows that thermal and athermal
jamming are fundamentally different transitions.
ORAL CONTRIBUTIONS Theor-Simul-18
Oral
Modeling of star-shaped polymer solutions using dedicated
massively-parallel device - ARUZ
K. Halagan1, M. Kozanecki
1, J. Jung
1, P. Polanowski
1, J. Ulanski
1,
K. Matyjaszewski12
1Department of Molecular Physics, Lodz University of Technology,
Zeromskiego 116, 90-924 Lodz, Poland 2Department of Chemistry, Carnegie Mellon University,
4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, USA
Simulation and modeling of polymer solutions and composites are pretty challenging because
usually involve very-long time scales (relaxation of chain, side groups) and broad range of
sizes to simulate, however play important role in prediction and explanation of experimentally
observed phenomenon. An interesting approach to simulation, based on cooperativity, was
proposed by Tadeusz Pakula – called Dynamic Lattice Liquid model [1]. Algorithm based on
this model assumes that diffusion steps of molecules are realized as a cooperative motion with
neighbors. DLL algorithm was successfully applied for various problems in polymer science,
like linear and cyclic polymer chains dynamics, gelation, intramolecular crosslinking,
polymer stars synthesis [2], solvent dynamics near brushed polymer chains [3] and others.
The dynamic properties and parallel nature of DLL gave basis for the idea of unique
massively-parallel simulator – ARUZ (Analyzer of Real Complex Systems) [4]. ARUZ is
installed in BioNanoPark Lodz (Poland) and is based on almost 26 000 FPGA devices (Field
Programmable Gate Array) working as signal processing units and connected in three-
dimensional network. The recently performed simulation involved the virtual synthesis of
polymer stars and dynamical investigation of their properties as well as solvent dynamics as a
function of star arm number, arm length and star concentration. Studies also involved the
structure, morphology and percolation phenomena for solvent and polymer.
REFERENCES
1. PAKULA, T., TEICHMANN J., Collective dynamics in simple supercooled and polymer liquids, J. Mol. Liq. 86,
109-121 (2000).
2. POLANOWSKI, P., JESZKA, J. K., MATYJASZEWSKI, K., Synthesis of star polymers by “core-first” one-pot
method via ATRP: Monte Carlo simulations, Polymer 55, 2552-2561 (2014).
3. KOZANECKI, M., HALAGAN, K., SARAMAK, J., MATYJASZEWSKI, K., Diffusive properties of solvent
molecules in neighborhood of polymer chain as seen by Monte-Carlo simulations, Soft Matter 12, 5493-5654
(2016).
4. KIELBIK, R., HALAGAN, K., ZATORSKI, W., JUNG, J., ULANSKI, J., NAPIERALSKI, A., RUDNICKI, K.,
AMROZIK, P., JABLONSKI, G., STOZEK, D., POLANOWSKI, P., MUDZA, Z.,
KUPIS, J., ARUZ - Large-scale, Massively Parallel FPGA-based Analyzer of Real Complex Systems, Comput.
Phys. Commun., in review, (2017).
Theor-Simul-19 ORAL CONTRIBUTIONS
Oral
Unifying the understanding of glassy dynamics in highly
asymmetric binary mixtures of hard spheres
Luis Fernando Elizondo Aguilera
Deutsches Zentrum für Luft- und Raumfahrt (DLR), 51170 Köln, Germany
Asymmetric binary mixtures of colloidal hard spheres are an important class of model
systems able to display a rich variety of dynamically arrested states, including colloidal gels,
different types of glasses and mixed states. They also open up the possibility to provide a
qualitative, and often quantitative, description of important processes which appear in many
biological environments and of fundamental relevance for materials science. In this
contribution [1] we combine molecular dynamics simulations [2], theoretical calculations
based on the self consistent generalized Langevin equation and experimental characterizations
[3], to report an unified description [4] and a general overview of the various glassy states and
dynamical arrest transitions occurring in a largely-asymmetric binary mixture of hard-spheres.
Specifically, we discuss the fundamental relevance in considering the dynamics of both
species to properly account for the whole glassy scenario of the system. Our findings suggest
that, for sufficiently large size disparity, both the molar composition and the total volume
fraction determine different decay patterns and relaxation times for the density correlations of
each species in the vicinity of each of the distinct glass boundaries. This picture is fully
consistent with the predicted existence of three different transition lines, which converge onto
a higher-order singularity in the parameters space of the mixture and which separates the
ergodic (fluid) region from two distinct types of glassy states.
REFERENCES
1. L.F. Elizondo Aguilera, E. Lázaro Lázaro, J.A. Perera-Burgos, T. Sentjabrskaja, G. Pérez Ángel, M. Laurati,
S. Egelhaaf, T. Voigtmann, M. Medina Noyola and R. Castañeda Priego, manuscript to be submitted (2017).
2. E. Lázaro Lázaro, P. Mendoza-Méndez, L.F. Elizondo Aguilera, J. A. Perera Burgos, P.E. Ramírez
González, G. Pérez Ángel, R. Castañeda Priego and M. Medina Noyola, JCP, 146, 185406 (2017).
3. T. Sentjabrskaja, et.al., Anomalus dynamics of intruders in a crowded environment of mobile obstacles. Nat.
Commun. 7:11133 doi: 10.1038/ncomms11133 (2016).
4. L.F. Elizondo Aguilera and T. Voigtmann, manuscript to be submitted (2017).
ORAL CONTRIBUTIONS Theor-Simul-20
Invited Talk
Elastically Collective Activated Relaxation in Bulk and
Confined Glass-Forming Liquids
Ken Schweizer, Steve Mirigian and Anh Phan
University of Illinois @ Urbana-Champaign, USA
A real space, quantitative, force-level dynamical theory of activated relaxation has been
formulated which combines elements of mode coupling theory, nonlinear Langevin equation
and dynamic free energy ideas for local hopping, and longer range collective elastic
fluctuations [1]. It addresses in a unified manner the apparent Arrhenius, dynamic crossover
and deeply supercooled regimes. The irreversible re-arrangement event has a mixed local-
nonlocal spatial character involving coupled cage-scale hopping and elastic distortion of the
surrounding liquid. This results in two related, but physically distinct, contributions to the
total barrier. The emergence of the more strongly temperature and density dependent elastic
barrier heralds the crossover to the deeply supercooled regime. Quantitative comparisons with
experiment and simulation for hard sphere fluids and suspensions reveals good agreement [1].
A quasi-universal, no adjustable parameter theory for molecular liquids is constructed via a
mapping to an effective hard sphere fluid which reproduces the material and thermodynamic
state dependent amplitude of equilibrium long wavelength dimensionless density fluctuations.
The theory accurately captures the key features of the alpha time over 14 decades, including
experimentally observed quasi-universalities [1]. Polymer melts are treated based on the
statistical Kuhn length as the elementary scale [2]. Free-standing thin films are described by
accounting for the modification of near surface caging constraints and nonlocal confinement-
induced reduction of collective elastic effects [3]. Film thickness and temperature dependent
spatial gradients of mobility, Tg and glassy modulus are predicted to emerge solely due to
dynamical effects, not changes in structure or thermodynamics. Many consequences on film-
averaged properties relevant to dynamic and pseudo-thermodynamic measurements are
determined. Extension to treat capped and supported films, bilayers and spherical droplets has
also been achieved. Large and qualitatively diverse effects of confining geometry and the
hardness versus softness of interfaces is predicted.
REFERENCES
1. Mirigian, S., Schweizer, K. S., J. Chemical Physics. 140,194506 and 194507 (2014).
2. Mirigian, S., Schweizer, K.S., Macromolecules. 48, 1901 (2015); 49, 9655 (2016).
3. Mirigian, S., Schweizer, K. S., JCP-Comm. 141,161103 (2014);JCP,143,244705(2015);JCP,146,203301
(2017).
Theor-Simul-21 ORAL CONTRIBUTIONS
Invited Talk
Strain hardening of glassy polymers : theory and
simulation
Luca Conca, Didier R. Long, Paul Sotta
Laboratory of Polymers and Advanced Materials, UMR 5268 – CNRS/Solvay, 69192 Saint-
Fons, France
Alain Dequidt
Institut de Chimie, Universite de Clermont-Ferrand, F-63000 Clermont-Ferrand
Over the past twenty years empirical evidence has shown that the dynamics in liquids close to the glass transition
temperature is strongly heterogeneous, on the scale of ξ ≃ 3 – 5 nm. A model for the dynamics of non-polar
amorphous polymers, based on percolation of slow domains, has been developed and solved by 3D numerical
simulations [1]. This so-called PFVD model succeeds in explaining many features observed in glassy polymers: the
heterogeneous nature of the dynamics, the violation of the Stokes law observed for small probes, ageing and
rejuvenation asymmetry, the shift of glass transition temperature in thin films. Experiments show that, under applied
deformation, polymers undergo yield at deformations of a few percent and stresses of some 10 MPa, followed by a
quick drop in stress and plastic flow, namely the strain-softening. Yield behavior is often described through the
phenomenological Eyring model, according to which stress reduces free energy barriers.
In our model, we propose that the elastic energy stored at the scale of dynamical heterogeneities effectively reduces the
free energy barriers between configurations and accelerates local dynamics [2]. After plastic flow, some polymers of
high molecular weight display an increase of stress with increasing strain in the large amplitude regime of
deformation. The typical slope, namely hardening modulus GR, is of order 107 – 10
8 Pa well below Tg. Classical
theories involving the entropic response of the rubbery network cannot explain such a high value. GR is also found to
increase upon cooling, as well as with strain rate and cross-linking density. The model of Chen et Schweizer [3], based
on the suppression of density fluctuations caused by a deformation-induced local anisotropy, reproduces many features
related to strain-hardening but lacks of a detailed spatial description. Analogously, we assume that local deformation
induces a reduction of mobility, at the scale of dynamical heterogeneities, by orienting monomers in the drawing
direction. We assume that consequent strengthening of monomer-monomer interactions results in a local increase of
the glass transition temperature. Simulations show hardening moduli GR of order 10 – 100 MPa a few 10 K below Tg.
This modulus decreases with temperature. The strain hardening regime is observed from strain amplitudes of about
20%. The effects of cross-linking and strain rate are studied and agree with experimental data. An enhanced ageing
process is observed at large strains and is key for strain hardening mechanism.
Acknowledgments:
L. Conca, D. Long and P. Sotta acknowledge support from the FP7-NMP-2011-EU-RUSSIA program
CompNanoComp, grant agreement 295355.
REFERENCES:
1. Dequidt, A., Long, D.R., P. Sotta, O. Sanséau, Eur. Phys, J. E 35, 61 (2012)
2. Dequidt, A. et al, Macromolecules (2016), 49, 9148−9162
3. Chen, K., Schweizer, K.S., Phys. Rev. Lett. 102, 038301 (2009)
4. Conca, L. PhD thesis, Lyon (2016)
ORAL CONTRIBUTIONS Theor-Simul-22
Invited Talk
Cooperative Dynamics and Memory Effects in the
Deformation and Flow of Glassy Materials
Joerg Rottler
Dept. of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road,
Vancouver BC V6T 1Z1, Canada
This presentation will explore particle scale processes during plastic deformation of
amorphous materials with molecular simulations. Macroscopic flow occurs in the form of
swift localized shear transformations in the background of a homogeneously deforming
medium. We show that these plastic events correlate with subtle structural features that can be
identified by soft quasilocalized vibrational modes [1]. The elastoplastic response of the
medium to a plastic event, as well as their mutual correlations, exhibit quadrupolar symmetry
that is characteristic of the shear stress redistribution following the local transformation [2,3].
At finite temperature, structural recovery occurs spontaneously due to thermal activation, and
the relaxation times grow as the glass slowly evolves or ages towards equilibrium. We show
that the evolution of the relaxation time can be quantitatively described in a mean-field
picture, where particle trajectories are computed from a continuous time random walk [4]. We
then compare the mean relaxation times during different deformation protocols to the
predictions of simple fluidity type models [5]. Time permitting, we also discuss briefly the
role of inertia in the shear rheology of amorphous solids.
REFERENCES
1. Smessaert, A., Rottler, J., Structural relaxation in glassy polymers predicted by soft modes: A quantitative
analysis, Soft Matter, 10, 8533 (2014)
2. Puosi, F., Rottler, J., Barrat, J. L., Time dependent elastic response to a local shear transformation in
amorphous solids, Phys. Rev. E 89, 042302 (2014)
3. Puosi, F., Rottler, J., and Barrat, J-L., Plastic response and correlations in athermally sheared amorphous
solids, Phys. Rev. E 94, 032604 (2016)
4. Warren, M., and Rottler, J., Quench, equilibration and subaging in structural glassses, Phys. Rev. Lett. 110,
025501 (2013)
5. Rottler, J., Relaxation times in deformed polymer glasses: a comparison between molecular simulations and
two theories, J. Chem. Phys. 145, 064505 (2016)
Theor-Simul-23 ORAL CONTRIBUTIONS
Invited Talk
Identifying the material time
Jeppe C. Dyre
Glass and Time, IMFUFA, Dept. of Science and Environment,
Roskilde University, Universitetsvej 1, DK-4000 Roskilde, Denmark.
In 1971 Narayanaswamy, an engineer at Ford Motor Company, proposed a simple, yet
powerful theory of physical aging [1]. Aging of glasses is known to be a highly nonlinear
process, but according to what became known as the Tool-Narayanaswamy (TN) theory,
aging is described by a linear time-convolution integral if time is replaced by the so-called
material time. The TN theory is highly successful, e.g., for describing relaxation following
small temperature jump, and it has been applied routinely in industry for decades.
Nevertheless, there have been only few attempts to justify the TN formalism from first
principles. The talk briefly reviews the TN formalism and shows recent data confirming the
theory in a novel, simplified form [2]. Finally, we show that the material time is determined
by the distance squared to a configuration of the system’s distant past [3].
REFERENCES
1. Narayanaswamy, O. S., J. Am. Ceram. Soc. 54, 491 (1971).
2. Hecksher, T., Olsen, N. B., and Dyre, J. C., J. Chem. Phys. 142, 241103 (2015).
3. Dyre, J. C., J. Chem. Phys. 143, 114507 (2015).
ORAL CONTRIBUTIONS Theor-Simul-24
Oral
Particle size effect on the dynamics of concentrated
polymers
Elias Mahmoudinezhad, Fathollah Varnik
Interdisciplinary Centre for Advanced Materials Simulation (ICAMS), Ruhr-Universität
Bochum, Universitätsstraße 150, 44780 Bochum, Germany
Using molecular dynamics simulations, the effect of small molecules on dynamical properties
of a model glass-forming polymer is investigated. In qualitative agreement with previous
studies [1-2], it is found that the structural relaxation becomes faster and the glass transition
temperature, as obtained from cooling simulations under constant pressure, decreases with the
concentration of small molecules. More importantly, we observe a non-monotonic
dependence of the relaxation dynamics on the size of small molecules at fixed number
concentration. These findings are corroborated by a detailed analysis of the temperature
dependence of relaxation times at various particle sizes via the mode coupling theory. The
critical temperature obtained from these investigations also show the non-monotonic effect,
independent of the chosen dynamical quantity such as the mean square displacement and the
autocorrelation function of the chain’s end-to-end vector. The data are also analyzed in the
context of fragility, revealing that the presence of small molecules leads to stronger glasses.
REFERENCES
1. Riggleman, R. A., Douglas, J. F., de Pablo, J. J., Tuning polymer melt fragility with antiplasticizer
additives, The Journal of Chemical Physics. 126, 234903 (2007).
2. Peter, S., Meyer, H., Baschnagel, J., MD simulation of concentrated polymer solutions: structural relaxation
near the glass transition, The European Physical Journal. E, Soft Matter. 28, 147-58 (2009).
Theor-Simul-25 ORAL CONTRIBUTIONS
Oral
Emergent facilitation behaviors in a distinguishable-
particle lattice model of glass
Chi-Hang Lam
Department of Applied Physics, Hong Kong Polytechnic University, Hong Kong, China
We propose an interacting lattice gas model of structural glass characterized by particle
distinguishability and site-particle-dependent random nearest-neighboring particle interactions
[1]. It exhibits non-trivial energetics while still admitting exact equilibrium states directly
constructible at arbitrary temperature and density. The dynamics is defined by activated
hopping following standard kinetic Monte Carlo approach without explicit facilitation rule.
Kinetic simulations show emergent dynamic facilitation behaviors in the glassy phase in
which motions of individual voids are significant only when accelerated by other voids
nearby. This provides a microscopic justification for the dynamic facilitation picture of
structural glass.
REFERENCES
1. Zhang, L.H., and Lam, C.H., arXiv:1608.05960 (2016).
ORAL CONTRIBUTIONS Theor-Simul-26
Oral
Time-convolutionless mode-coupling theory for short-range
attractive colloids
Takayuki Narumi1 and Michio Tokuyama
2
1Yamaguchi University, Ube, Japan,
2Tohoku University, Sendai, Japan
Short-range attractive colloids are prominent in studies of the glass transition. For systems of
the attraction range smaller than about one tenth of the particle diameter, mode-coupling
theory (MCT) predicted melting of a glass by cooling and the direct transition between
repulsive and attractive glasses. We here study the glass transition of short-range attractive
colloids to validate a theory recently proposed by Tokuyama: time-convolutionless mode-
coupling theory (TMCT) [1, 2].
Using numerical calculations for the square-well system as a model of the short-range
attractive colloids, we have presented numerical evidence for the existence of the glass-liquid-
glass reentrant, the glass-glass transition, and the higher-order (i.e., A3 and A4) singularities in
the TMCT analysis [3]. It has been also demonstrated through the comparisons with the
results of molecular dynamics for the binary attractive colloids that TMCT improves the
critical values of the volume fraction. In addition, we introduced a schematic model of three
control parameters. It is thus confirmed that TMCT can describe the glass-glass transition and
higher-order singularities even in such a schematic model. The results have given a
counterexample to a concern that TMCT could not describe the glass-glass transition nor the
higher-order singularities [4].
Since TMCT has the same form of the memory function of MCT, our analysis enhances the
utility of the MCT framework for the study of glass transition. In the presentation, we will
present the details of TMCT for short-range attractive colloids.
REFERENCES
1. Tokuyama, M., “Statistical-mechanical theory of nonlinear density fluctuations near the glass transition”,
Physica A. 395, 31-47 (2014).
2. Tokuyama, M., “Time-convolutionless mode-coupling theory near the glass transition - A recursion formula
and its asymptotic solutions” , Physica A 430, 156-170 (2015).
3. Narumi, T., and Tokuyama, M., “Analyses of kinetic glass transition in short-range attractive colloids based
on time-convolutionless mode-coupling theory”, Phys. Rev. E. 95, 032601 (2017).
4. Götze, W., and Schilling, R., “Glass transitions and scaling laws within an alternative mode-coupling
theory”, Phys. Rev. E. 91, 042117 (2015).
Theor-Simul-27 ORAL CONTRIBUTIONS
Oral
Distinct disordered glassy states of soft spheres
Moumita Maiti and Michael Schmiedeberg
University of Erlangen-Nuremberg, Staudtstrasse 7, 91058 Erlangen, Germany
Approaching zero temperature a repulsive soft sphere system explores hard-sphere like
behavior. We consider repulsive harmonic potential and explore densities below athermal
jamming density and temperature regime close to zero. At early time we observe a disordered
state of larger contact number. Then the system transits to another disordered state of lower
contact number. There is no issue with crystallization for the bidisperse system, and for
monodisperse packing we discard the states with crystallites and then analyze. From the
analysis of the mean squared displacement, we observe a broader plateau for the second
disordered state. The late time behavior like diffusivity also changes from one disordered state
to the other. The disordered state with larger contact number can be interpreted as the
behavior of soft spheres which later transits to hard-sphere like behavior. From the
extrapolation to higher densities, this might imply that a soft sphere glass is different from the
hard sphere glass.
ORAL CONTRIBUTIONS Theor-Simul-28
Oral
On the production of entropy during glass transition
Hicham Jabraoui1, Saïd Ouaskit
2, Jean-Luc Garden
3,4
1 : Institut Jean-Barriol, FR2843 CNRS, Faculté des Sciences et Techniques, 54506
Vandoeuvre les Nancy, Université de Lorraine, France
2 : Laboratoire Physique de la Matière Condensée (LPMC), Université Hassan II de
Casablanca, Faculté des Sciences Ben M’Sik, Casablanca Maroc
3 : Institut Néel, CNRS, 25 avenue des Martyrs, F-38042 Grenoble France,
4 : Université Grenoble Alpes, Institut Néel, F-38042 Grenoble France
In the description of solid-state physics phenomena, a two-level-system (TLS) is often used as
a simple model to calculate the equilibrium thermodynamic properties from the partition
function. In particular, the equilibrium heat capacity of a TLS undergoes a Schottky anomaly
at low temperatures. Nevertheless, a TLS can also bring interesting information on the
dynamics of complex systems when it is coupled to a master equation approach. As shown
few years ago by J. Bisquert1, it is possible to simulate the frozen-in of the configurational
energy and the configurational entropy during cooling, and accordingly, the vanishing of the
configurational heat capacity during a glass transition. Other interesting features can be
simulated within this simple framework, like the ‘negative specific heat’ overshoot measured
at the beginning of the heating. In particular, we can calculate the so-called Tool’s fictive
temperature. Here, we use such a framework, especially the fictive temperature, in order to
calculate and explicitly simulate the production of entropy during cooling and successive
heating at different temperature rates. Although the model is too simple to explain all the
experimentally observed effects during a real glass transition, it is somehow useful for
pointing out the difference between configurational entropy variation and production of
entropy involved during a glass transition. Finally, by means of such simulations, we verify
the Clausius theorem, confirming that glasses obey non-equilibrium thermodynamics
REFERENCES
1. Bisquert, J., Master equation approach to the non-equilibrium negative specific heat at the glass
transition, Am. J. Phys. 73, 735-741 (2005).
TV-1 ORAL CONTRIBUTIONS
Invited Talk
Thermodynamic scaling of vibrational dynamics and
relaxation: insights from anharmonic elasticity
F. Puosi1,2
, S. Bernini1, O. Chulkin
1, S. Capaccioli
1,3, D. Leporini
1,3
1Dipartimento di Fisica ‘Enrico Fermi’, Università di Pisa, Largo B Pontecorvo 3, I-56127
Pisa, Italy
2Sciences et Ingénierie des Matériaux et Procédés (SIMaP), UMR CNRS 5266, Grenoble
INP, UGA 1130 Rue de la Piscine, BP 75, 38402 Saint-Martin d’Hères Cedex, France
3 IPCF-CNR, UOS Pisa, Italy
We compare molecular dynamics simulations and experiments concerning the
thermodynamic scaling (TS) of vibrational dynamics and slow relaxation of a polymer melt
[1,2]. Two distinct models, with strong and weak virial-energy correlations, are considered.
Both models evidence the joint TS scaling, with the same characteristic exponent ts , of the
fast mobility <u2> —the mean square amplitude of the picosecond rattling motion inside the
cage—and the much slower structural relaxation and chain reorientation [1]. For the
glassformer OTP, we show that the knowledge of the isochoric fragility allows to
satisfactorily predict the TS master curve (TSMS) of the fast mobility with no adjustments.
Building on the universal correlation between <u2> and the structural relaxation time [1],
as well as the relation of the fast mobility with the anharmonic elasticity [2], we find two
expressions of TSMS for . They are nearly equivalent in accuracy and with two adjustable
quantities (a shape-setting parameter and a narrowly-bounded vertical shift), i.e. one less than
the available alternatives. Both theoretical TSMS fit well with the experimental TSMS of
thirty-four glassformers and, in particular, the slope at the glass transition, i.e., the isochoric
fragility [1,2]. Furthermore, we: i) express the TS characteristic exponent ts in terms of the
lattice Grüneisen parameter L and the isochoric anharmonicity L, ii) identify L as the shape-
setting parameter of TSMS [2]. A linear relation between the isochoric fragility and the
isochoric anharmonicityL is found and compared favourably with the results of experiments
with no adjustable parameters.
REFERENCES
1. Puosi, F., Chulkin, O., Bernini, S., Capaccioli, S., Leporini, D., Thermodynamic scaling of vibrational
dynamics and relaxation, J.Chem.Phys. 145, 234904 (2016).
2. Bernini, S., Puosi, F., Leporini, D., Thermodynamic scaling of relaxation: insights from anharmonic
elasticity, J. Phys.: Condens. Matter. 29, 135101 (2017).
ORAL CONTRIBUTIONS TV-2
Invited Talk
Experimental support of the isomorph theory – and beyond
Kristine Niss
Glass and Time, IMFUFA, Department of Science and Environment, Roskilde University,
P.O. Box 260, DK-4000 Roskilde, Denmark
The isomorph theory is an approximative theory, which has been shown to predict the
behavior of simple computer simulated liquids (e.g. LJ-systems) with surprisingly high
precision, while it does not hold for complex systems with directional bonds or competing
interactions1. In order to test the isomorph theory experimentally we have focused on van der
Waals bonded glass-forming liquids.
We have experimentally verified several predictions of the isomorph theory; the density
scaling exponent can be found from single state-point thermo-mechanical measurements2, the
dielectric amplitude under pressure follows the isomorph prediction3, isochronal lines in the
P-T phase diagram are the same for different response functions4, and the picosecond
dynamics is invariant along alpha relaxation isochrones close to Tg5.
Moreover, we have found that the dynamics of van der Waals bonded liquids with no visible
beta relaxation is even simpler than what can be predicted from isomorph theory4,6
: 1) the
spectral shape of the alpha relaxation is independent of both temperature and pressure in a
dynamical range of at least 10 decades, and 2) the alpha-relaxation time of different response
functions, which probe different dynamical properties all follow the same temperature and
pressure dependence. Based on this we propose that a basic (ideal-gas type) model of the
dynamics of glass-forming liquids should encompass this simplicity in a natural way, while
still exhibiting the dynamical hall-mark features; non-exponentieal spectral shape and non-
Arrhenius temperature dependence of the alpha-relaxation time.
REFERENCES
1. Dyre, J.C., Hidden Scale Invariance in Condensed Matter, J. Phys. Chem. B 118, 10007 (2014)
2. Gundermann, D. et al. Predicting the density scaling exponent from Prigogine-Defay ratio measurements,
Nature Physics. 7, 816 (2011)
3. Wence, X. et al .Isomorph theory prediction for the dielectric loss variation along an isochrone, J. Non
Chryst Solid. 407, 190 (2015)
4. Roed, L, Niss, K., Jacobsen, B. Communication: High pressure specific heat spectroscopy reveals simple
relaxation behavior glass forming molecular liquid, J. Chem. Phys. 143, 221101 (2015).
5. Wase-Hansen, H. et al in preparation (2017)
6. Niss, K. and Hecksher, T., in preparation (2017)
TV-3 ORAL CONTRIBUTIONS
Invited Talk
Static and dynamic correlation lengths in glass forming
liquids: comparison of temperature dependence
D.N Voylov1, P.J. Griffin
2, B. Mercado
3, J.K. Keum
4, M. Nakanishi
5, V.N.
Novikov1, A.P. Sokolov
1,6
1Department of Chemistry, University of Tennessee, Knoxville, TN 37996, USA
2Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia,
PA 19104-6272, USA
3Chemistry Department, Yale University, New Haven, CT 06511, USA
4Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
5Department of Electrical Engineering, Fukuoka Institute of Technology, Fukuoka 811-0295,
Japan
6Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
We performed a detailed analysis of the temperature dependence of static structure factor
S(Q) in several glass forming liquids [1]. The analysis revealed that the temperature variations
of the width of the main diffraction peak Q(T), and, respectively, of the structure correlation
length, lc ~ 2/Q, are the stronger the higher is the fragility of these liquids. This observation
suggests a direct connection between rather subtle variations of structure and the sharp
slowing down of structural relaxation in glass forming liquids at decreasing temperature.
Relation of theQ(T) variations to other definitions of the structural fragility suggested for
bulk metallic glasses in Refs. [2,3] is discussed. We show also that the temperature
dependence of the structural correlation length lc(T) ~ 2/Q(T) resembles that of the size of
the Adam-Gibbs cooperatively rearranging regions Lcoop(T) found from the experimental α-
relaxation times within the Adam-Gibbs approach.
REFERENCES
1. Voylov, D.N., Griffin, P.J., Mercado, B., et al, Correlation between temperature variations of static and
dynamic properties in glass forming liquids, Phys. Rev. E. 94, 060603(R)(6) (2016).
2. Zhao, Y., Bian, X., Qin, X., Qin, J., and Hou, X., Phys. Lett. A. 367, 364 (2007).
3. Mauro, N. A., Blodgett, M., Johnson, M.L., Vogt, A. J., and Kelton, K. F., Nature Commun. 5, 1 (2014).
ORAL CONTRIBUTIONS TV-4
Invited Talk
Viscosity of the Lennard-Jones fluid
L. Costigliola1, M. Heyes
2, T. B. Schrøder
1, J. C. Dyre
1
1 Glass and Time'', IMFUFA, Department of Science and Environment, Roskilde University,
P.O. Box 260, DK-4000 Roskilde, Denmark
2 Department of Mechanical Engineering, Imperial College London, Exhibition Road, South
Kensington, London SW7 2AZ, United Kingdom
The steady-state shear viscosity of the Lennard-Jones (LJ) fluid has been evaluated at more
than one hundred state points using the SLLOD algorithm, covering number densities ρ
varying between 0.9 and 3.4 and temperatures T from the triple point temperature to several
hundred (LJ units) [1]. Most of the state points studied are supercritical. The data are well
described by the following equation for the (macroscopically) reduced viscosity, (ρ,T)=
exp[B(TF(ρ)/T)1/2
] in which TF(ρ) is the freezing temperature as a function of density and B =
2.49. This equation may be justified in part by reference to the isomorph theory [2, 3],
although the exponent 1/2 remains to be derived theoretically. The paper also reports data for
the diffusivity, which violate the Stokes-Einstein relation at high temperatures. The findings
are discussed in light of other representations of the LJ viscosity's variation throughout the
phase diagram.
REFERENCES
1. Costigliola, L., Isomorph theory and extensions, PhD thesis (2016), http://dirac.ruc.dk/~lorenzoc/.
2. Gnan, N., Schrøder, T. B., Pedersen, U. R., Bailey, N. P., Dyre, J. C., Pressure-energy correlations in
liquids. IV. ‘Isomorphs’ in liquid phase diagrams, J. Chem. Phys. 131, 234504 (2009).
3. Dyre, J. C., Hidden scale invariance in Condensed Matter, J. Phys. Chem. B. 118, 10007 (2014).
TV-5 ORAL CONTRIBUTIONS
Invited Talk
New understanding of collective modes and
thermodynamics of the liquid state
Kostya Trachenko
Queen Mary University of London, 327 Mile End Road, London E1 4NS, UK
E-mail [email protected]
A theory of liquids and liquid-glass transition requires understanding most basic
thermodynamics properties of the liquid state such as energy and heat capacity. This has
turned out to be a long-standing problem in physics. Landau&Lifshitz textbook states that no
general formulas can be derived for liquid thermodynamic functions because the interactions
are both strong and system-specific. Phrased differently, liquids have no small parameter.
Recent experimental and theoretical results open a new way to understand liquid
thermodynamics on the basis of collective modes (phonons) as is done in the solid state
theory. There are important differences between phonons in solids and liquids, and we have
recently started to understand and quantify this difference. I will review collective modes in
liquids including high-frequency solid-like transverse modes and will discuss how a gap in
the reciprocal space emerges and develops in their spectrum. This reduces the number of
phonons with temperature, consistent with the experimental decrease of constant-volume
specific heat with temperature [1]. I will discuss the implication of the above theory for the
liquid-glass transition and the change of heat capacity at Tg.
I will also mention how this picture can be extended above the critical point where the
recently proposed concept of the Frenkel line on the phase diagram separates liquid-like and
gas-like states of supercritical dynamics [1].
REFERENCES
1. Trachenko, K., and Brazhkin, V. V., Collective modes and thermodynamics of the liquid state, Reports on
Progress in Physics. 79, 016502 (2016).
ORAL CONTRIBUTIONS TV-6
Invited Talk
Viscoelastic Effects And Dynamic Crossover In
Supercritical Fluids
T. Bryk
Institute for Condensed Matter Physics NASU, Lviv 79011, Ukraine
Lviv Polytechnic National University, Lviv 79013, Ukraine
E-mail [email protected]
Viscoelastic effects in dynamics of liquids like positive sound dispersion (PSD),
emergence of short-wavelength shear and heat waves are discussed on the basis of
generalized hydrodynamic theory and molecular dynamics simulations [1,2]. In
particular the main focus is on the origin of a deviation of dispersion law of acoustic
collective excitations from the hydrodynamic linear dispersion and its density
dependence for supercritical fluids. Analytical solutions of several dynamic models
are reported in the long-wavelength region for longitudinal and transverse dynamics,
that allows to estimate the width of hydrodynamic region in which all the
hydrodynamic asymptotes are valid.
I report an effect of temperature fluctuations on longitudinal dynamics and show that
they are responsible for negative contribution to PSD, which can cause even
“negative” sound dispersion for fluids close to the critical point. Another issue
discussed in my talk is a recent claim that the positive dispersion of sound is caused by
transverse excitations [3]. I will compare the results of [3] with recent data from
molecular dynamics simulations of supercritical fluids on dispersion of longitudinal
and transverse excitations and analytical results for propagation gap of transverse
excitations in liquids.
REFERENCES
1. GORELLI, F.A., BRYK, T., KRISCH, M., RUOCCO, G., SANTORO, M., SCOPIGNO, T., Dynamics and
thermodynamics beyond the critical point, Scientific Reports. 3, 1203:1-5 (2013).
2. BRYK, T., MRYGLOD, I., SCOPIGNO, T., RUOCCO, G., GORELLI, F., SANTORO, M., Collective
excitations in supercritical fluids: Analytical and molecular dynamics study of “positive” and “negative”
dispersion, J. Chem. Phys. 133, 024502 (2010).
3. FOMIN, YU.D., RYZHOV, V.N., TSIOK, E.N., BRAZHKIN, V.V., TRACHENKO, K., Crossover of
collective modes and positive sound dispersion in supercritical state, J.Phys.:Condens.Matt. 28, 43LT01
(2016).
TV-7 ORAL CONTRIBUTIONS
Invited Talk
Theory of thermodynamics of freezing and melting
U. R. Pedersen , L. Costigliola, N. P. Bailey, T. B. Schrøder, K. Niss, J. C.
Dyre
Glass and Time, IMFUFA, Dep. of Science and Environment,
Roskilde Uni., Roskilde, Denmark
Freezing of liquids are well known by laymen and are fundamental for many areas of the
sciences. We present a theoretical framework [1] for the thermodynamics of freezing.
Properties of the crystal and liquid at a single state-point allow one to predict the coexistence
pressure as a function of melting temperature, as well as the variation along the
melting/freezing lines of quantities such as the reduced crystalline vibrational mean-square
displacement (the Lindemann ratio), the liquid diffusion constant or the viscosity. The
fundamental assumption is hidden scale-invariance of liquid and crystalline states [2,3]. An
analytical expression is available for systems of particles interacting via pair potentials that
are differences of two inverse power laws. The theory is validated by computer simulations of
the freezing and melting properties of the 6-12 Lennard-Jones system [4] and experimental
data of dimethyl phthalate and indomethacin [5].
REFERENCES
1. Pedersen, U. R., Costigliola, L., Bailey, N. P., Schrøder, T. B., and Dyre J. C., Nature Comm. 7, 12386
(2016).
2. Gnan, N., Schrøder, T. B., Pedersen, U. R., Bailey, N. P., and Dyre, J. C., J. Chem. Phys. 131, 234504
(2009).
3. Schrøder, T. B., and Dyre, J. C., J. Chem. Phys. 141, 204502 (2014).
4. Pedersen, U. R., J. Chem. Phys. 139, 104102 (2013).
5. Pedersen, U. R., Adrjanowicz, K., Niss, K., Bailey, N. P., scipost.org/submissions/1702.01010v1 (2017).
ORAL CONTRIBUTIONS TV-8
Invited Talk
A new formulation of the Isomorph Theory – and beyond
Thomas Schrøder
Glass & Time, Dept. of Science and Environment, Roskilde University, Denmark
The original formulation of the Isomorph Theory [1] predicts that some liquids have
"isomorphs", i,e,, lines of invariant dynamics, structure and excess entropy in parts of their
phase diagram. Here we present a new - and more elegant - version of the theory, which from
a single assumption regarding the scaling properties of the high-dimensional potential energy
surface predicts the existence of isomorphs [2]. The new version of the theory solves some of
the (few) problems of the original version, e.g., the variance of heat capacity along an
isomorph is now accurately predicted. Finally, we will discuss the extension to
"pseudoisomorphs" in liquids and polymers with intramolecular vibrational degrees of
freedom [3]. A pseudoisomorph is a line in the phase diagram with invariant dynamics and
structure, but not invariant excess entropy. We demonstrate a method by which an
isomorph/pseudoisomorph (depending on the system) can – in principle – be identified from
a single equilibrium configuration.
REFERENCES
1. N. Gnan, T.B. Schrøder, U.R. Pedersen, N.P. Bailey, and J.C. Dyre, "Pressure-energy correlations in
liquids. IV. 'Isomorphs' in liquid state diagrams", Journal of Chemical Physics v131, p234504 (2009).
2. T.B. Schrøder and J.C. Dyre, "Simplicity of condensed matter at its core: Generic definition of a Roskilde-
simple system", Journal of Chemical Physics, v141, p204502 (2014).
3. A.E. Olsen, J.C. Dyre, and T.B. Schrøder, "Communication: Pseudoisomorphs in liquids with
intramolecular degrees of freedom", Journal of Chemical Physics, v145, p241103 (2016).
Ultras-G-1 ORAL CONTRIBUTIONS
Invited Talk
Surface Diffusion of Molecular Glasses and Its Relation to
Vapor-Deposited Stable Glasses
Lian Yu
University of Wisconsin - Madison
The preparation of stable glasses by vapor deposition relies on enhanced mobility of surface
molecules relative to bulk molecules. We have measured the surface diffusion of 10 organic
glasses composed of molecules of different sizes and degrees of hydrogen bonding. Surface
diffusion is extremely fast in o-terphenyl (a relatively small hydrocarbon), outpacing bulk
diffusion by 100 million times at Tg. Surface diffusion slows down significantly with
increasing molecular size and intermolecular hydrogen bonds, while bulk diffusion shows a
weaker variation. Molecular size and hydrogen bonding appear to have a similar effect on the
rate of surface crystal growth and the stability of vapor-deposited glasses as they do surface
diffusion. The molecular size effect on surface diffusion is consistent with a steep gradient of
molecular mobility beneath the free surface; the hydrogen bonding effect on surface diffusion
is attributed to the conservation of hydrogen bonds on going from the bulk to the surface.
REFERENCES
1. Chen, Y., Zhang, W., Yu, L. Hydrogen Bonding Slows Down Surface Diffusion of Molecular Glasses, J.
Phys. Chem. B. 120, 8007–8015 (2016).
2. Zhang, W., Yu, L. Surface diffusion of polymer glasses, Macromolecules. 49, 731–735 (2016).
3. Zhang, W., Brian, C. W., Yu, L. Fast Surface Diffusion of Amorphous o-Terphenyl and its Competition
with Viscous Flow in Surface Evolution, J. Phys. Chem. B. 119, 5071–5078 (2015).
4. Zhu, L., Brian, C., Swallen, S. F., Straus, P. T., Ediger, M. D., Yu, L. Surface Diffusion of an Organic
Glass, Phys. Rev. Lett. 106, 256103 (2011).
ORAL CONTRIBUTIONS Ultras-G-2
Invited Talk
Structure and dynamics of highly stable glasses prepared
by physical vapor deposition
Mark Ediger
Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53705 USA
Glasses formed by cooling a liquid inherit both their structure and their marginal stability
from the liquid state. In contrast, glasses prepared by vapor deposition need have neither of
these limitations. By utilizing the high mobility present near the free surface of many organic
glasses, one can prepare glasses that are similar to highly aged ordinary glasses, with low
enthalpy and high thermal stability. Two recent experiments document additional features of
these tightly packed glasses: 1) the beta relaxation can be suppressed by nearly a factor of
four in vapor-deposited toluene glasses, and 2) the trans-cis isomerization in an azobenzene
glassformer can be suppressed by a factor of fifty. On the other hand, we have recently
learned that hydrogen-bonding reduces surface mobility and thus impedes the ability to form
a highly stable glass.
Molecules at the free surface of the glass during deposition may prefer anisotropic packing
arrangements – and these can be trapped into the glass by vapor deposition. For organic
semiconductors such as the molecules used in OLEDs, anisotropic packing can improve
device performance. Based upon a mechanism established by computer simulations, we can
predict the anisotropy of vapor-deposited glasses from knowledge of the molecular
arrangement preferred at the free surface. For molecules with a strong surface anchoring, such
a liquid crystals, deposition can result in highly ordered solids that inherit their structure from
the free surface structure. On the other hand, even a highly spherical molecule (carbon
tetrachloride) can form stable glasses, indicating that molecular anisotropy is not required to
access highly stable packing arrangements.
Ultras-G-3 ORAL CONTRIBUTIONS
Invited Talk
Thermal transport in stable glasses
J. Rodríguez-Viejo1, J. Ràfols-Ribé
1, P. Ferrando-Villalba
1, M. González-
Silveira1, Ll. Abad
2, A. F. Lopeandia
1
1Group of Nanomaterials and Microsystems, Universitat Autònoma de Barcelona, 08193
Bellaterra, Spain,
2Institut de Microelectrònica de Barcelona, Centro Nacional de Microelectrònica−CSIC,
Cerdanyola del Vallès, 08193, Spain
It is already well stablished that many organic film glasses grown by PVD at temperatures
below the glass transition temperature show higher densities and higher thermodynamic and
kinetic stabilities compared to a conventional glass obtained from the liquid at a cooling rate
of 10 K/min. In addition, depending on the molecular shape of the specific molecule PVD
glasses can exhibit packing anisotropies that also depend on the deposition temperature. The
effect of density variation and molecular anisotropy on the transport properties of organic
PVD stable glasses has been scarcely studied up to now. We have recently developed a
modification of the 3ω-Völklein technique that enables in-situ measurements of the thermal
conductance of thin films during their growth. The methodology is based on the modification
of the in-plane thermal conductance of a thin disordered silicon nitride membrane during
growth of different materials onto its surface. We have used this method to measure the in-
plane thermal conductivity, κ, of TPD films grown in a temperature range spanning 60-97%
of the glass transition temperature. We observe a 15% variation in the value of κ in the
measured temperature interval, being the highest and the lowest values, obtained respectively
at 95 % and 65 % of Tg. These results contrast with the heat capacity measurements in which
the layers deposited at the 0.85Tg show the maximum of stability. Interestingly, the variation
of the thermal conductance appears to be dominated by changes in molecular packing
anisotropy of the glass, while the density variations seem to play a minor effect on thermal
transport. The high accuracy and resolution, 𝛥(𝜅 · 𝑡) = 0.065𝑊
𝑚·𝐾· 𝑛𝑚 of this technique can
be used to monitor in real-time the early stages of stable film formation. We will show that
the variation of the in-plane thermal conductance, K, during the initial growth stages of the
organic layer can be correlated with the microstructure of the film. Initially, we observe a
reduction of K due to nucleation and island formation. During island coalescence, K reaches a
minimum and at the percolation threshold starts to rise again. Subsequent island percolation
produces a sharp rise of the conductance and upon complete coverage K increases linearly.
Percolation threshold and complete coverage, linked to molecular mobility, occur at different
nominal thickness depending on the material and the growth conditions.
ORAL CONTRIBUTIONS Ultras-G-4
Invited Talk
The Role of Surface-Mediated Equilibration in the
Formation of Stable Glasses
Zahra Fakhraai, Tianyi Liu, Yue Zhang, Sarah Wolf, Patrick Walsh
Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 10104, USA
Stable glasses, produced by physical vapor deposition, can access low energy configurational
states that may take liquid-quenched glasses hundreds or millions of years to access. It has
been hypothesized that surface-mediated equilibration (SME) due to enhanced molecular
motion at the free surface of the glass allows these glasses to overcome large
thermodynamical barriers to access these low energy states.
In this presentation, direct measurements of molecular diffusion on the surface of ultra-stable
glasses are presented and it is demonstrated that the free surface motion remains fast on the
surface of both liquid-quenched and ultra-stable glasses and invariant of the stability of the
glass. Through a series of measurements of the properties of ultra-thin films of glasses with
various degrees of stability the details of the mechanism of stable glass formation is
discussed.
The role of molecular shape, intermolecular interactions, and intra-molecular degrees of
freedom in the SME process, producing glasses with various degrees of stability, and other
physical properties of ultra-stable glasses are also discussed.
Ultras-G-5 ORAL CONTRIBUTIONS
Oral
Mechanical response of ultrastable glasses
Misaki Ozawa, Andrea Ninarello, and Ludovic Berthier
Laboratoire Charles Coulomb, Universite de Montpellier, Place Eugene Bataillon 34095
Montpellier Cedex 5, France
Mechanical response of amorphous solids is a fundamental research topic in glass science. Whereas
amorphous solids respond elastically to a small strain (or stress), the system eventually yields at a large
strain, showing plastic response. Although amorphous solids such as glasses are ubiquitous and relevant for
industrial applications, understanding of mechanical response is still poor.
Computer simulations play an important role in this field, since they are able to provide atomic resolution
of mechanical response of glasses. However, there are huge gaps in the accessible timescales between
ordinary computer simulations and experiments in terms of glass preparation (e.g. cooling rate) and
timescale of deformation (e.g. strain rate). Timescale of current computer simulations are about 10 orders
of magnitudes smaller, behind as compared to that of experiments, which makes possible studies of poorly
annealed glasses with very large strain rate. For the strain rate, one can overcome the timescale gap by
using the athermal quasi-static shear (zero strain rate limit) method which neglects thermal fluctuations [1].
However, fast cooling rate of ordinary simulations still prevents us from studying glasses in experimental
condition.
Recently, we have developed very efficient simulation setup using particle swap Monte-Carlo algorithm
with size polydisperse particles [2]. By applying this setup for a realistic glass-forming system with a
continuous potential in three dimensions, we produce very well-annealed glasses whose cooling rate is even
slower than experiments, that is ultrastable glasses. We perform athermal quasi-static shear deformation on
these systems. Aim of this work is to establish the first simulation study of mechanical response of glasses
in and beyond experimental timescales in both cooling and strain rates [3].
Our athermal quasi-static shear simulation of the ultrastable glasses show qualitatively different behaviors
from ordinary computer glasses [3]. 1) Sharp yielding transition: The stress-strain curve of the ultrastable
glasses show very big stress overshoot and sharp yielding, which corresponds to shear band spanning entire
sample. With the help of the finite size scaling, we unambiguously determine the yielding transition point
at the thermodynamic limit. 2) Burst of stress drops before yielding: We observe sudden emergence of
burst of stress drops slightly before the yielding transition point, which can be regarded as a precursor of
the yielding. 3) Strong persistent initial memory: After the yielding transition, the systems do not converge
to a steady state until more than 1000% shear strain, which is in stark contrast to ordinary computer glasses.
REFERENCES
1. Maloney, C E., and Lemaitre, A., Amorphous systems in athermal, quasistatic shear, Phys. Rev. E. 74,
016118 (2006).
2. Berthier, L., Coslovich, D., Ninarello, A., and Ozawa, M., Equilibrium Sampling of Hard Spheres up to the
Jamming Density and Beyond, Phys. Rev. Lett. 116, 238002 (2016).
3. Ozawa, M., Ninarello, A., and Berthier, L., in preparation.
ORAL CONTRIBUTIONS Ultras-G-6
Invited Talk
Effects of deposition rate on the stability and dynamics of
ultrathin layers of vapor-deposited glycerol
M. Wübbenhorst, A. Kasina, S. Schulze, T. Putzeys,
Soft Matter and Biophysics section, Department of Physics and Astronomy, KU Leuven,
Belgium
Department of Physics and Space Science, School of Physical Sciences and Technology,
Technical University of Kenya, Kenya
MEET Battery Research Center, Institute of Physical Chemistry, University of Muenster,
Germany
Functional Organic Materials and Devices, Department of Chemical Engineering and
Chemistry TU/e Eindhoven University of Technology, The Netherlands
We have investigated the kinetics of the recovery of vapor deposited, stable glasses of glycerol to its
“normal” supercooled liquid state in detail. While conventional “stable” glass formers recover the
equilibrium liquid state by surface dominated devitrification, for glycerol this recovery proceeds in
two steps, namely devitrification and a 2nd
(MROL/OL) transformation [1], the melting of rigid polar
clusters, the existence of which has been reported recently [2].
First, the kinetics of devitrification was studied by isothermal experiments monitoring the increase in
the (unrelaxed) specific heat and the strength of the dielectric -process with time [3]. Here, an
Arrhenius-type temperature dependence of the devitrification time td was observed, proving that the
“melting” of the high-density glass is governed by the glass/liquid interfacial dynamics. Opposed to
devitrification, the second transformation around -60°C could be interpreted as a thermally stimulated
relaxation process, indicating that the MROL/OL conversion comprises random, thermally activated
melting of rigid polar clusters. The activation energy of Ea = 122kJ/mol supports our molecular picture
of a RPC melting that involves both energetic (multiple H-bonds, dipole-dipole interactions) and
entropic barriers.
Finally, we discuss effects of the deposition rate on the glass stability and various relaxation processes
in the glassy state in relation to local packing phenomena in glassy glycerol.
REFERENCES
1. Capponi, S., Napolitano, S., Wübbenhorst, M., Supercooled liquids with enhanced orientational order, Nature
communications 3, 1233-1-7 (2012).
2. Kasina, A., Putzeys, T., Wübbenhorst, M., Dielectric and specific heat relaxations in vapor deposited glycerol, J. Chem.
Phys. 143, 244504-1 - 244504-11, (2015).
3. Kasina, A., Schulze, S., Wübbenhorst, M., Unique two step liquid recovery in vapor deposited glassy glycerol,
submitted (2017).
4. Kasina, A., Schulze, S., Wübbenhorst, M., Effect of deposition rate on the glassy and liquid dynamics of vapor
deposited glycerol, submitted (2017)
Ultras-G-7 ORAL CONTRIBUTIONS
Invited Talk
Nanocalorimetry as a route to understand vapour deposited
glasses
M.Gonzalez-Silveira, J.Ràfols-Ribé, C.Rodríguez-Tinoco, J.Rodríguez-Viejo
Grup of Nanomaterials and Microsystems, Physics Department, Universitat Autònoma de
Barcelona, 08193 – Bellaterra (Barcelona, Spain)
Glasses are ubiquitous in our daily life. They are present in TV-screens, in the medicines we
take or as metallic components of everyday use objects among many more. The control of the
stability of these glasses and the exact knowledge of their physico-chemical properties is
fundamental to be able to predict their performance when put to use. In this sense, it has been
shown that by using physical vapor deposition it is possible to tune the characteristics of the
produced thin film glasses. Properties such as thermal stability, density or even the
transformation mechanism are very sensitive to the deposition conditions. The most extended
technique to perform a thermal characterization of the glass transition is calorimetry. We want
to show here that a thorough analysis of the calorimetric curves can provide valuable
information on the properties of these glasses. A clear example is the determination of the
transformation mechanism of these vapor deposited glasses, which can be dominated either
by a heterogeneous surface front or by a homogenous bulk process depending on the
deposition conditions of the glass but also on the thickness of the film or even the heating rate
that is being used for the calorimetric measurement. Moreover, some differences are observed
between the intrinsic mechanisms controlling the kinetics of the homogeneous and
heterogeneous processes. Only the heterogenous mechanism seems to be sensitive to a factor
such as molecular geometry. We also show that by using membrane based nanocalorimetry,
which allows to measure at a wide range of heating rates (10-1
-105 K/s), it is possible to study
the transformation at temperatures not accessible by conventional calorimetry, being the glass
transition a kinetic event.
ORAL CONTRIBUTIONS Ultras-G-8
Invited talk
Bulk Ultrastable Glasses Produced Using Particle-Swap
Simulations
Christopher J. Fullerton
Laboratoire Charles Coulomb, Université de Montpellier, Montpellier, France
Vapor deposition is an experimental method of producing thin glass films which are highly
stable, taking up to 105 times longer to melt to the liquid than their equilibrium relaxation
times [1]. Until now simulations have not been able to produce glasses with anything like this
stability. Using an efficient particle-swap algorithm [2] in monte carlo and molecular
dynamics simulations we are able to produce bulk hard sphere and Lennard-Jones glasses
which are of comparable stability to the vapor-deposited films. We melt these glasses at
constant volume and constant pressure to demonstrate that the high density of ultrastable
glasses compared to the equilibrium liquid plays an important role in their high kinetic
stabilty. This work paves the way for further study of bulk ultrastable glasses and deeply
supercooled liquids at temperatures and densities where, until now, reaching equilibrium has
been impossible.
REFERENCES
1. Sepùlveda, A., Tylinksi, M., Guiseppi-Elie, A., Richert, R., Ediger, M.D., Role of Fragility in the
Formation of Highly Stable Organic Glasses, Phys. Rev.Lett. 113,Z 045901 (2014).
2. Berthier, L., Coslovich, D., Ninarello, A., Ozawa, M., Equilibrium Sample of Hard Spheres Up To the
Jamming Density and Beyond, Phys. Rev. Lett. 116, 238002 (2016).
Ultras-G-9 ORAL CONTRIBUTIONS
Invited Talk
Stable glass-forming ability and time needed to form a
kinetically stable glass
Y. Z. Chua,1 M. Ahrenberg,
1 M. Tylinski,
2 S. Tatsumi,
3 M. D. Ediger,
2 C.
Schick1
1University of Rostock,
2Univery of Wisconsin-Madison,
3Kyoto Institute of Technology
Physical vapor deposition (PVD) has been used to prepare organic glasses with very high
kinetic stability. However not all molecules, when vapor deposited using condition expected
to yield stable glasses, form kinetically stable glasses. Therefore it is useful to define the
prerequisites for stable glass formation, e.g. fragility and molecular anisotropy. It has been
observed that most stable glass-formers have high fragility and anisotropic molecular
structures. To investigate these prerequisites to the stable glass-forming ability,
ethylcyclohexane with relatively low fragility, m = 57, and tetrachloromethane with nearly
isotropic molecular structure are investigated with in situ AC nanocalorimetry. Both
ethylcyclohexane and tetrachloromethane have successfully formed kinetically stable glasses
when deposited at about 0.8 of the glass transition temperature, Tg. This strongly argues that
fragility and molecular asymmetry are not the prerequisites for stable glass formation, but
depends on the deposition conditions, e.g. substrate temperature during deposition and
deposition rate. Isothermal transformation of the as-deposited glasses of ethylcyclohexane
into the supercooled state is investigated for the deposition rate dependency, covering four
orders of magnitude, at different substrate temperatures. The kinetic stability of the glasses
shows strong deposition rate dependency for lower substrate temperatures. The data provide
an estimate for the substrate temperature dependent free surface residence time needed for the
molecules in the assumed mobile surface layer to promote stable glass formation. Stable
glasses are formed if this time is of the order of the β-relaxation time, many orders of
magnitude faster than the α-relaxation at the substrate temperature.
ORAL CONTRIBUTIONS Ultras-G-10
Invited Talk
How to create equilibrium vapor deposited glasses
Elijah Flenner1, Ludovic Berthier
2, Patrick Charbonneau
3, Francesco
Zamponi4
1Department of Chemistry, Colorado State University, Fort Collins, CO 80523
2Laboratoire Charles Coulomb, UMR 5221, Universite de Montpellier and CNRS, 34095
Montpellier, France
3Department of Chemistry, Duke University, Durham, NC 27708 and Department of Physics,
Duke University, Durham, NC 27708
4Laboratoire de physique theorique, Ecole normale superieure, PSL Research University,
Sorbonne Universites, UPMC Univ. Paris 06, CNRS, 75005 Paris, France
Vapor deposited glasses have higher density, higher kinetic stability, and lower heat capacity
compared to their liquid cooled counterparts. These properties make them promising materials
for a range of applications from pharmaceutical to electronics. While it is believed that
enhanced surface mobility is the mechanism that allows for vapor deposition to create
exceptional glasses, it is unclear how the surface mobility is related to the final glass state. We
use molecular dynamics and Monte Carlo simulations to quantify the relationships mobility,
surface and bulk, and the final glass state of vapor deposited glasses and liquid cooled glass.
We show that for a model glass former that the surface mobility plays the same role in the
formation of vapor deposited glasses as the bulk mobility does for liquid cooled glasses.
Ultras-G-11 ORAL CONTRIBUTIONS
Invited Talk
Inherent Structure Energy as an Indicator for Stability in
Glasses
Julian Helfferich1, Ivan Lyubimov
2, Daniel Reid
2, Juan J. de Pablo
2
1Steinbruch Center for Computing and Institute for Nanotechnology, Karlsruhe Institute of
Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
2Institute for Molecular Engineering, University of Chicago, 5640 South Ellis Avenue,
Chicago, IL 60637, USA
The ability to control the properties of a specific material is at the heart of materials research.
Thus, significant interest has been generated by the discovery that physical vapor deposition
(PVD) can be facilitated to control various properties ranging from an unparalleled stability
[1] to more complex properties such as the anisotropy [2]. It has been shown that other
pathways can lead to ultrastable glasses as well [3] and that an increased stability can be
reproduced in numerical simulations [4,5]. While the notion of stability is easy to grasp on an
intuitive level, it is not clearly defined and various observables have been studied to assess the
stability. We have found that the inherent structure (IS) energy correlates strongly with the
mobility in the glassy system [6], making it a good candidate to gauge the stability. Besides
being accessible at a very small numerical cost, it can be intuitively understood in the
theoretical picture of the potential energy landscape. In this talk, I will give a short
introduction into benefits and challenges of different indicators used to asses the stability of
glasses and discuss how the inherent structure energy fits into this picture.
REFERENCES
1. Swallen, S. F., Kearns, K. L., Mapes, M. K., Kim, Y. S., McMahon, R. J., Ediger, M. D., Wu, T., Yu, L.,
Satija, S., Organic Glasses with Exceptional Thermodynamic and Kinetic Stability, Science. 19, 353-356
(2007).
2. Dalal, S. S., Walter, D. M., Lyubimov, I., de Pablo, J. J., Ediger, M. D., Tunable Molecular Orientation and
Elevated Thermal Stability of Vapor-Deposited Organic Semiconductors, Proc. Natl. Acad. Sci. U.S.A. 112,
4227-4232 (2015).
3. Wang J. Q., Chen, N., Liu, P., Wang, Z., Louzguine-Luzgin, D. V., Chen, M. W., Perepezko, J. H., The
Ultrastable Kinetic Behavior of an Au-based Nanoglass, Acta Mater. 79, 30-36 (2014).
4. Singh, S., Ediger, M. D., de Pablo, J. J., Ultrastable Glasses from in silico Vapour Deposition, Nat. Mater.
12, 139-144 (2013)
5. Danilov, D., Hahn, H., Gleiter, H., Wenzel, W., Mechanisms of Nanoglass Ultrastability, ACS Nano. 10,
3241-3247 (2016)
6. Helfferich, J., Lyubimov, I., Reid, D., de Pablo, J. J., Inherent Structure Energy is a Good Indicator of
Molecular Mobility in Glasses, Soft Matter. 12, 5898-5904 (2016)
ORAL CONTRIBUTIONS Ultras-G-12
Oral
Anti-Aging in ultrastable metallic glasses
Martin Lüttich1,2
, Valentina M. Giordano3, Sylvie Le Floch
3, Eloi Pineda
4,
Federico Zontone2, Yuansu Luo
1, Konrad Samwer
1, Beatrice Ruta
3,2
1I. Physikalisches Institut, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
2ESRF – The European Synchrotron, CS 40220, 38043 Grenoble Cedex 9, France
3Institute of Light and Matter, UMR5306 Université Lyon 1 – CNRS, Université de Lyon, 69622
Villeurbanne Cedex, France 4Department of Physics, Universitat Politécnica de Catalunya-BarcelonaTech, Esteve Terradas 8,
Castelldefels 08860, Spain
Metallic glasses (MGs) show outstanding mechanical, physical and chemical properties and
so provide a whole class of materials at the cutting-edge research in metallic and glassy
systems1. However, MGs suffer from aging, which is the spontaneous degradation of their
physical properties. Ultrastable metallic glasses (UMGs) are a very promising candidate to
solve stability issues of conventionally produced MGs and the study of their stability is
therefore of exceptional interest2.
By means of x-ray photon correlation spectroscopy (XPCS), we are able to probe structural
relaxations at the atomic length scale in MGs. With that, we reveal surprisingly fast structural
relaxation dynamics of UMGs, which are in the order of 40s to 100s at 0.71Tg. Similar results
were reported for conventional metallic glasses, strengthening the idea of the existence of
localized atomic motion3. Despite this common behavior associated to the probed length
scale, previous thermal treatments affect the dynamics of UMGs in a completely different
way with respect to quenched materials. While conventional MGs are usually pre-annealed to
improve their stability, pre-annealing UMG results in an even faster structural relaxation
dynamics – and will so be called Anti-Aging. The results are discussed in terms of the
potential energy landscape.
REFERENCES
1. Wang, W.-H., The elastic properties, elastic models and elastic perspectives of metallic glasses, Prog.
Mater. Sci. 57, 487–656 (2012).
2. Yu, H.-B., Luo, Y. & Samwer, K., Ultrastable metallic glass, Adv. Mater. 25, 5904–5908 (2013).
3. Ruta, B., et al. Atomic-Scale Relaxation Dynamics and Aging in a Metallic Glass Probed by X-Ray Photon
Correlation Spectroscopy, Phys. Rev. Lett. 109, 165701 (2012).
Ultras-G-13 ORAL CONTRIBUTIONS
Oral
Growth of ultrastable glass layers for maximizing organic
light-emitting diode performance
Joan Ràfols-Ribé1, Paul-Anton Will
2, Christian Hänisch
2, Marta González-
Silveira1, Simone Lenk
2, Javier Rodríguez-Viejo
1, Sebastian Reineke
2
1 Group of Nanomaterials and Microsystems, Universitat Autònoma de Barcelona, 08193
Bellaterra, Spain
2 Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute
for Applied Physics, Technische Universität Dresden, 01069 Dresden, Germany
Amorphous layers prepared by means of physical vapour deposition (PVD) of small organic
molecules are widely used in organic light-emitting diodes (OLEDs). While most of the
research is mainly focused on the development of new materials and device architectures,
little attention has been paid to the properties of each glassy layer. At the same time, in recent
years, there has been also an increasing interest in using PVD technique as a powerful
strategy to define the properties of evaporated amorphous layers. For many organic small
molecule glass-formers, it has been shown that the kinetic and thermodynamic stability, the
density or orientation of the molecules can be improved and tuned by properly setting the
substrate temperature during deposition. Particularly, when settled around 85 % of the glass
transition temperature —expressed in Kelvin— glasses with the most outstanding features can
be achieved. Here, we use a simple phosphorescent OLED, consisting of only two organic
layers, to check the influence of the deposition temperature on the OLED performance.
OLEDs comprising a green emitter achieve external quantum efficiencies of 19.4 % and 23.9
% at a current density of 1 mA/cm2 for deposition temperatures of 300 K and 343 K,
respectively, reflecting a significant enhancement of 23 %. Other emitters (red, an additional
green and blue) were tested at these two temperatures using the same OLED architecture
achieving also significant maximum improvements of 15 %, 22 % and 165 %, respectively, at
a luminance of 100 cd/m2. Moreover, an enhancement of the lifetimes of the green and red
devices is also attained. The improvement of thermodynamic and kinetic stability of the
emission and electron transport layer as a function of deposition temperature is presented as a
possible cause for this significant enhancement. This simple possibility to optimize the
deposition conditions of the active layers provides a new strategy to achieve high efficiency
OLEDs.
ORAL CONTRIBUTIONS Ultras-G-14
Invited talk
Dielectric processes in vapour deposited organic glasses
C. Rodriguez-Tinoco1,2
, M. Rams-Baron1,2
, J. Rodriguez-Viejo3, M. Paluch
1,2
1 Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland.
2 Silesian Center for Education and Interdisciplinary Research, 75 Pulku Piechoty 1A, 41-500
Chorzow, Poland.
3 Grup de Nanomaterials i Microsistemes, Departament de Física, Universitat Autònoma de
Barcelona, 08193 Bellaterra
Broadband dielectric spectroscopy (BDS) has proven to be an exceptional tool to investigate the
dynamics of organic liquids1. In particular, BDS is fundamental to understand the nature of the
fast molecular movements taking place before structural relaxation is triggered. Some of these fast
processes are believed to be precursors of the structural relaxation of glasses2. Furthermore, BDS
is a very powerful technique to investigate the charge transport phenomena in some organic
systems3. On the other hand, vapour deposition (VD) burst into the field some years ago due to
the ability to produce glasses with exceptional density levels (ultrastable glass)4 and particular
molecular arrangement5. VD glasses represent an excellent benchmark to test the dynamical
behaviour of glasses, studying the effect of both density and molecular orientation levels that are
not attainable by other means.
Here, we present some recent results concerning the dielectric properties of vapour deposited
glasses of different materials. We investigate the effect of ultrastability on the secondary
relaxation process of ultrastable Etoricoxib. We suggest that the secondary process in the glassy
state behaves in an analogous way to the structural relaxation, reinforcing the idea that the
secondary processes are a precursor for the structural relaxation. We also show that in the case of
vapour deposited glasses of TPD, a prototypic organic hole transport material, a new dielectric
process which is not present in the conventional glass emerges. We attribute this to the
enhancement of the charge transfer between molecules due to the particular molecular
arrangement of VD. This finding shows not only that vapour deposition is a powerful tool to
produce organic materials with enhanced charge mobility, fundamental to produce more efficient
electronic devices, but also reinforces BDS as a powerful technique to investigate the properties
of other charge transport organic materials and other vapour deposited glasses.
REFERENCES
4. Kremer, F., Schönhals, A., Broadband dielectric spectroscopy. Springer (2003).
5. Ngai, K. L., Relaxation and Diffusion in Complex Systems. Springer-Verlag (2011)
6. Somik Banerjee, S., Kumar, A.. Journal of Applied Physics. 109, 114313 (2011).
7. Swallen, S., et al.. Science. 315, 5810, 353-356 (2007).
8. Dalal, S., et al. PNAS. 112, 14, 4227–4232 (2015).
Ultras-G-15 ORAL CONTRIBUTIONS
Invited Talk
How slow does a glass flow?
E.A.A. Pogna1, C. Rodríguez-Tinoco
2, G. Cerullo
1, C. Ferrante
3, J. Rodríguez
Viejo2 and T. Scopigno
3
1. Physics Department, Politecnico di Milano, I-20133, Milano, Italy
2. Nanomaterials and Microsystems Group, Physics Department, Universitat Autonoma de
Barcelona, ES-08193, Bellaterra, Spain
3. Physics Department, Università degli studi di Roma La Sapienza, I-00185, Roma, Italy
A pivotal aspect for modern glass transition theories is the existence of a finite temperature
where the viscosity diverges. Answering this question, is hampered by the fundamental
unfeasibility of direct experimental investigations of viscosity in the glass phase, which would
require impractically long time. This limitation is circumvented by exploiting the correlation
[1] of the slow diffusive motion described by viscosity, with the vibrational properties of the
glass as function of its stability. The mechanical response of the glass depends on the shape of
the potential energy minima it can explore. Being metastable, the glass spontaneously evolves
towards lower, i.e. more stable, configurations. The stability can be quantified by fictive
temperature Tf as determined from the endothermic jump of specific heat upon fast heating
the glass. The dependence of the vibrational properties on the stability is investigated by
comparing a number of glasses of Indomethacin (a fragile glass-former) with different Tf,
spanning a range of 20 K, prepared by physical vapor deposition. By combining inelastic x-
ray scattering [2] with Brillouin light scattering in frequency and time domain, the energy
dispersion of the longitudinal vibrational modes and the sound attenuation are determined.
Finite viscosity values, far below the glass transition temperature, are finally retrieved from
the sound velocity of the ultrastable glasses [3]. Our results suggest that the conventional
wisdom picture of a glass ceasing to flow at finite temperature could be wrong, and lead to
reconsideration of those paradigms based on the dynamical divergence, to ever reach a
definitive understanding of the glass transition.
REFERENCES
1. Scopigno, T., Ruocco, G., Sette, F., Monaco, G., Science 302, 849-852 (2003).
2. Pogna, E. A. A., Rodríguez-Tinoco, C., Krisch, M., Rodríguez-Viejo, J., Scopigno, T. Sci. Rep. 3, 2518
(2013).
3. Pogna, E. A. A., Rodríguez-Tinoco, C., Ferrante, C., Cerullo, C., Rodríguez-Viejo, J., Scopigno, T., PNAS.
12 2331-2336 (2015).
ORAL CONTRIBUTIONS Ultras-G-16
Invited Talk
Fossilized two-level systems and boson peak in amber
glasses
Miguel Ángel Ramos
Laboratorio de Bajas Temperaturas, Departamento de Física de la Materia Condensada,
Condensed Matter Physics Center (IFIMAC) and Instituto Nicolás Cabrera,
Universidad Autónoma de Madrid, 28049 Madrid, Spain
Recent experiments1 conducted in hyperaged geological glasses, mainly in Spanish amber
from El Soplao (112 million years old) will be presented and discussed. After characterization
of their elastic and thermodynamic properties (finding an extraordinary reduction 8% of the
fictive temperature due to the extremely long aging of amber), its specific heat was measured
at low and very low temperatures. By directly comparing pristine amber samples (i.e. highly
stabilized polymer glasses after aging for millions of years) to the same samples after being
totally or partially rejuvenated, we have found that the two most prominent universal
“anomalous” low-temperature properties of glasses, namely the tunnelling two-level systems
and the so-called “boson peak”, persist essentially unchanged in these hyperaged geological
glasses. Therefore, non-Debye low-energy excitations of glasses appear to be robust, intrinsic
properties of non-crystalline solids which do not vanish by accessing to very deep states in the
potential energy landscape1.
Besides, we have observed an unexpected suppression of the two-level systems in the
ultrastable glass of indomethacin2, whereas conventionally prepared thin films of the same
material exhibit the usual linear term in the specific heat below 1 K ascribed to these universal
two-level systems in glasses. By comparing both kinds of highly-stable glass, we conclude
that the disappearance of the tunnelling two-level systems in ultrastable thin films of
indomethacin may be rather due to specific structural peculiarities of the material.
REFERENCES
1. Pérez-Castañeda, T., Jiménez-Riobóo, R. J., Ramos, M.A., Two-Level Systems and Boson Peak Remain
Stable in 110-Million-Year-Old Amber Glass, Phys. Rev. Lett. 112, 165901 (2014).
2. Pérez-Castañeda, T., Rodríguez-Tinoco, C., Rodríguez-Viejo, J., Ramos, M.A., Suppression of tunneling
two-level systems in ultrastable glasses of indomethacin, PNAS. 111, 11275 (2014).
Ultras-G-17 ORAL CONTRIBUTIONS
Invited Talk
Ultra-stable Glasses and the "Unexplored Region" of
Volume-Temperature Space
Gregory B. McKenna, Heedong Yoon, Sindee L. Simon, and Yung P. Koh
Dept. Chem. Engn., Texas Tech University, Lubbock, TX 79409-3121 USA
Recent developments in glass physics have led to the possibility of exploring a regime of the
isobaric volume-temperature surface that has previously been little examined. This
"unexplored region" results from the ability to make ultra-dense glasses using various
methods, two of which we will examine here. The unexplored region is that of the low fictive
temperature Tf glass in the temperature regime between Tf and Tg, the nominal glass transition
temperature. This is the region in which the density and enthalpy of the glass are much lower
than their equilibrium values [1,2]. Correspondingly, one would expect that the relaxation
times in this region are longer than those in the equilibrium state at the same temperatures.
The glasses can be obtained either by waiting extremely long times or by vapor deposition
methods. The former we achieved by using a 20 million year old amber material which had a
fictive temperature some 43.6 K below the Tg [2]. More recently we have used a vacuum
pyrolysis method [3,4] to make ultra-stable amorphous fluoropolymer films which have
fictive temperatures of as much as 57 K below the nominal Tg. While with the amber material
one can perform macroscopic experiments to probe the behavior in the unexplored region of
interest, the case of the vacuum pyrolysis formed glass leads to samples of nano- to micro-
gram quantities and the determination of the dynamics between Tf and Tg becomes
problematic. To overcome this difficulty, we have begun making viscoelastic measurements
on the ultra-stable polymer films using the TTU nanobubble inflation technique[5]. Results of
our excursions into the "unexplored region" of glassy materials will be presented.
REFERENCES
1. Kovacs, A. J., "Transition Vitreuse dans les Polyméres Amorphes. Etude Phénoménologique", Fortschr.
Hochpolym.-Forsch. 3, 394–507 (1963).
2. Zhao, J., Simon, S. L., and McKenna, G. B., Using 20-million-year-old amber to test the super-Arrhenius
behaviour of glass-forming systems", Nat. Commun. 4:1783, 1–6 (2013).
3. Nason, T. C., and Lu, T.-M., "Thermoplastic and Spectroscopic Properties of Amorphous Fluoropolymer
Thin Films", Thin Solid Films. 239, 27-30 (1994).
4. Yoon, H. D., Koh, Y. P., Simon, S. L., and McKenna, G. B., "An Ultra-Stable Polymeric Glass: Amorphous
Fluoropolymer with Extreme Fictive Temperature Reduction by Vacuum Pyrolysis", Macromolecules.
under review.
5. O'Connell, P.A., and McKenna, G. B., "Novel Nanobubble Inflation Method for Determining the
Viscoelastic Properties of Ultrathin Polymer Films", Rev. Sci. Instrum. 78, 013901−1−013901−12 (2007).
ORAL CONTRIBUTIONS Water-HB-1
Invited Talk
Dielectric Susceptibility and Neutron Scattering of Liquid
Water: A Unified Description
Juan Colmenero
Materials Physics Center (CSIC-UPV/EHU), University of the Basque Country, San
Sebastian (Spain)
Water dynamics has paramount importance in many areas of research and industrial
applications. One of the main techniques used from the early times to investigate water
dynamics is dielectric spectroscopy (DS). Thanks to the development of the tera-herz (THz)
techniques it was recently possible to fill the gap between dipolar relaxation and
intermolecular streatching vibrations at ≈5THz and to have a full picture of the dielectric
permittivity of liquid water in a broad frequency range. However, the microscopic
understanding of the dielectric spectrum of water and the nature of the molecular motions
involved in the different dielectric processes are still very unclear. This is mainly due to the
fact that DS is a 'macroscopic' technique, which follows the fluctuations of the total dipole
moment of the system without spatial resolution. Interestingly, the relevant frequency range
for the dielectric response of liquid water can also be covered by neutron scattering (NS), a
tehnique delivering microscopic information with spatial/time resolution.
In a recent work [1], we have considered DS data together with coherent and incoherent NS
results of water at room temperature. The NS data were analyzed in terms of the
corresponding susceptibility –a less conventional way that allows distinguishing better the
different processes involved as well as the comparison with spectroscopy DS data. We have
also carried out molecular dynamics (MD) simulations in order to unveil the microscopic
origin of the different processes involved. We achieve a unified description of both NS and
DS susceptibilities, which allows clarifying the nature of the different relaxation processes,
the molecular motions involved in the DS spectra and their impact on the structural
relaxation. These results also open a new way of approaching dynamics of water under
different conditions (supercooled, confined, etc.) and that of other H-bonded liquids [2].
REFERENCES
1. Arbe, A., Malo de Molina, P., Alvarez, F., Frick, B., and Colmenero, J., Dielectric susceptibility of liquid
water: microscopic insights from coherent and incoherent neutron scattering, Phys. Rev. Lett. 117, 185501
(2016).
2. Malo de Molina, P., Alvarez, F., Arbe, A., Frick, B., Wildes, A., and Colmenero, J., Structure and dynamics
of aqueous Proline solutions, PCCP. (submitted).
Water-HB-2 ORAL CONTRIBUTIONS
Invited Talk
Dielectric Relaxation Dynamics of Water
P. Lunkenheimer, S. Emmert, and A. Loidl
Experimental Physics V, Center for Electronic Correlations and Magnetism, University of
Augsburg, 86159 Augsburg, Germany
In this talk, we discuss the true nature of the dielectric relaxation properties of water in the
GHz - THz frequency range. It is known that several microscopic dynamic processes
contribute to the dielectric spectra of water. However, their contributions strongly
superimpose each other and are difficult to resolve and, thus, their number, spectral form, and
microscopic origins are highly controversial. Consequently, many contradicting
interpretations of water spectra exist in literature and it is essentially impossible to test their
correctness, based on the existing experimental data.
We have solved this problem in a twofold way [1]: At first, in a several years long effort, we
have determined the dielectric constant and loss of pure water in a broad and almost
continuous frequency range at different temperatures with unprecedented precision. This
avoids all ambiguities of previous studies arising from the composition of broadband water
spectra from different sources and considerably extends the data base available in literature,
where most work was done at room temperature only. Moreover, and most importantly, we
demonstrate that broadband measurements up to the THz range of water solutions with an
admixed salt reveal very similar behavior as pure water, showing all the so far mysterious
spectral features occurring in the pure liquid. Such measurements provide the unique
opportunity to study these processes at temperatures far below 0°C because in such solutions
ice formation can be easily suppressed. This enables a much better deconvolution of the
different processes, because, at low temperatures, their superposition is less severe.
Based on these experiments, we conclude that the dielectric spectra of water should be
interpreted along similar lines as those of common supercooled dipolar liquids. Its room-
temperature spectra seem to be governed by the same processes as those liquids at elevated
temperatures. Especially, we provide clear evidence for an absorption process in water
somewhat above 1 THz corresponding to the "boson peak", which is a well-known feature of
glass-forming liquids.
REFERENCES
1. Lunkenheimer, P., Emmert, S., Gulich, R., Köhler, M., Wolf, M., Schwab, M., Loidl, A.,
Electromagnetic-radiation absorption of water, arXiv:1612.01457.
ORAL CONTRIBUTIONS Water-HB-3
Invited Talk
X-ray studies of water; from Hot to Supercooled Conditions
Anders Nilsson
Division of Chemical Physics, Department of Physics, Stockholm University, Sweden
This talk will describe recent x-ray spectroscopy and scattering measurements both static and
in the time domain, using both synchrotron radiation and the x-ray laser, at temperatures from
hot to deep supercooling and all the way to boiling. Both dynamics and structure obtained
from x-ray scattering will be presented. The connection of these results to low and high
density water and the 2nd
critical point model will be discussed.
Water-HB-4 ORAL CONTRIBUTIONS
Invited Talk
New X-ray Experiments on Amorphous water: The high- to
low-density transition
K. Amann-Winkel1, F. Perakis
1,2, F. Lehmkühler
3,4, M. Sprung
3,
D. Pettersson1, J. A. Sellberg
5, H. Pathak
1, A. Späh
1, F. Cavalca
1,2,
D. Schlesinger1, A. Ricci
3, A. Jain
3, B. Massani
6, F. Aubree
6, C. J. Benmore
7,
T. Loerting5, G. Grübel
3,4, L. G. M. Pettersson
1, A. Nilsson
1
1 Department of Physics, Stockholm University, Sweden
2 SLAC National Accelerator Laboratory, USA
3 Deutsches Elektronen-Synchrotron DESY, Germany,
4 Hamburg Centre for Ultrafast Imaging, Germany
5 Biomedical and X-ray Physics, Department of Applied Physics, KTH, Sweden
6 Institute of Physical Chemistry, University of Innsbruck, Austria
7 X-ray Science Division, Advanced Photon Source Argonne National Laboratory, USA
The amorphous forms of water play an important role in the understanding of water´s
anomalous properties. Since the discovery of distinct amorphous states with different density
(high- and low density amorphous ice, HDA and LDA) it has been controversially discussed
whether this phenomenon of polyamorphism at high pressures is connected to the occurrence
of two distinct liquid phases (HDL and LDL) [1,2,3]. Calorimetric and Dielectric
measurements show evidence for a glass transition at ambient pressure in both amorphous
states at two different temperatures [4]. However, the nature of both, the experimentally
observed glass transition as well as the high-to-low-density transition is still under debate
[5 and references therein]. Alternatively, HDA has been discussed as mechanically collapsed
crystal, unrelated to liquids [6]. Our recent results using X-ray diffraction as well as X-ray
correlation spectroscopy (XPCS) support the previous findings of HDA undergoing a glass-
liquid transition at ambient pressure around 110 K and are consistent with the hypothesis of a
liquid-liquid transition between HDL and LDL.
REFERENCES
1. Mishima, O., Stanley, H.E., The relationship between liquid, supercooled and glassy water, Nature. 396,
(1998)
2. Limmer, D.T.. Chandler, D., Theory of amorphous ices, PNAS. 111, 9413 (2014)
3. Gallo P., et al., Water a Tale of Two Liquids, Chem. Rev. 116, 7463 (2016)
4. Amann-Winkel, K., Gainaru, C., et al., Water’s second glass transition, PNAS. 110, 17720 (2013)
5. Amann-Winkel, K., et al., Water´s controversial glass transition, Rev. Mod. Phys. 88, 0110002 (2016)
6. Tse, J.S., Klug, D.D., Pressure amorphized ices – an atomistic perspective, PCCP. 14, 8255 (2012)
ORAL CONTRIBUTIONS Water-HB-5
Invited Talk
The Glass Transition of Water in Bulk, Mixtures, and
Confinements
Michael Vogel
Institut für Festkörperphysik, TU Darmstadt, Hochschulstr. 6, 64289 Darmstadt, Germany
We combine computational and experimental approaches to investigate the properties of
supercooled water in the bulk, in binary mixtures, and in silica confinements.
In MD simulations, we exploit the possibility to create water-like molecules with grossly
different dynamics by scaling the molecular dipole moment. Decomposing the activation
energy of the structural relaxation according to E(T) = E +Ec(T), we show that all water-like
models share a universal relation between the high-temperature limit E and Tg and that the
cooperative contribution Ec(T) has an exponential temperature dependence. To determine the
length scale of cooperative dynamics, we study water-like molecules in neutral confinements,
which are formed by fixed fractions of the respective molecules [1,2]. We demonstrate that
the strong slowdowns of dynamics when approaching the glass transition or a solid surface
can be described in the same theoretical framework [3].
The interpretation of experimental results on the glass transition of water in mixtures and
confinements, in particular, the role of a proposed liquid-liquid phase transition, is still highly
controversial [4]. In this context, the high propensity of water for crystallization is a major
problem. We study water in silica pores with various diameters to systematically alter the
crystallization behavior [5,6]. Combining nuclear magnetic resonance and broadband
dielectric spectroscopy studies with calorimetric characterization, we show that water exhibits
two dynamical crossovers. Near 225 K, depending on pore diameter, the dynamics of liquid
water changes in response to the appearance of a solid fraction, leading to a change from
bulk-like to interface-dominated motion. Near 185 K, the temperature dependence is altered
as a consequence of a glass transition of interfacial water.
REFERENCES
1. Klameth, F., Vogel, M., J. Chem. Phys. 138, 134503 (2013)
2. Klameth, F., Henritzi, P., Vogel, M., J. Chem. Phys. 140, 144501 (2014)
3. Klameth, F., Vogel, M., J. Phys. Chem. Lett. 6, 4385-4389 (2015)
4. Cerveny, S., Mallamace, F., Swenson, J., Vogel, M., Xu, L., Chem. Rev. 116, 7608-7625 (2016)
5. Sattig, M., Vogel, M., J. Chem. Phys. Lett. 5, 174-178 (2013)
6. Rosenstihl, M., Kämpf, K., Klameth, F., Sattig, M., Vogel, M., J. Non-Cryst. Solids. 407, 449-458 (2015)
Water-HB-6 ORAL CONTRIBUTIONS
Invited Talk
Water structure and dynamics on surfaces
Limei Xu
International Center for Quantum Materials, Peking University, China
Water plays important roles in biological, environmental and engineering processes. When
water is in contact with medium, the hydrogen bond network of water is interrupted. As a
result, the configuration of water at interface differs significantly from that of bulk water, e.g.,
the structure and dynamics of hydrogen bonds, which plays an important role for the property
of water. Based on molecular dynamics simulation and density functional theory, we
investigate the structure and dynamics of water. Our results show that the non-hydrogen
bonded OH groups based on the commonly used hydrogen bond definition are significantly
different from the free OH groups. We also show that the microscopic structure of water at
interface reflects its macroscopic property of interfaces.
ORAL CONTRIBUTIONS Water-HB-7
Invited Talk
Water at biomembranes: structure, dynamics and influence
on ion adsorption.
Carles Calero, Giancarlo Franzese a,b
a Departament de Física de la Matèria Condensada, Universitat de Barcelona, Martí Franquès
1, 08028 Barcelona, Spain. b
Institut de Nanociència i Nanotecnologia, Universitat de Barcelona, Av. Joan XXIII S/N,
08028 Barcelona, Spain
Biological membranes provide a limiting structure which separates the interior and exterior of
cells and organelles. Being selectively permeable, they control the flow of substances in and
out of the cell, which permits to regulate its composition and the communication between
cells through signaling with ions. In the fulfillment of these functions, interfacial water plays
a fundamental role, since it mediates in the interaction of the membrane with other
biomolecules (such as proteins, sugars or other membranes), and it determines the
electrostatic properties of the membrane.
In this contribution we discuss the properties and role of interfacial water in both membrane
functions. We investigate using all-atom molecular dynamics simulations the properties of
confined water in between interacting phospholipid membranes [1]. We show that both the
translational and rotational relaxation dynamics of water molecules exhibit a monotonic
dependence with the distance between confining membranes. We show that the dynamics of
water molecules can be understood using a layering model with the help of a local definition
of distance to the membrane. We also discuss the effect of interfacial water on the adsorption
of ions to phospholipid membranes [2].
References
1. Calero, C.; Stanley, H. E.; Franzese, G. Structural Interpretation of the Large Slowdown of Water
Dynamics at Stacked Phospholipid Membranes for Decreasing Hydration Level: All-Atom Molecular
Dynamics, Materials, 9, 319 (2016).
2. Yang, J.; Calero, C.; Bonomi, M.; Martí, J. Specific ion binding at phospholipid membrane surfaces, J.
Chem. Theor. and Comp. 11, 4495 (2015).
Water-HB-8 ORAL CONTRIBUTIONS
Invited Talk
Ice nucleation near the liquid-liquid critical point in
simulations of supercooled water
Peter H. Poole
Department of Physics, St. Francis Xavier University, Antigonish, Nova Scotia B2G 2W5,
Canada
Computer simulations of the ST2 model of water have demonstrated a well-characterized
liquid-liquid phase transition (LLPT) [1,2] in the supercooled region of this model's phase
diagram [3]. However, the influence of the LLPT on the nucleation of ice in this model has
not been quantified, in particular, the influence on the height of the nucleation barrier. Using
umbrella sampling Monte Carlo simulations, we present estimates of the free energy barrier
for ice nucleation near the Widom line [4], as well as our results for the barrier close to the
LLPT itself [5]. We find that the nucleation barrier decreases, but does not vanish, on
approaching the LLPT, consistent with previous results that show that the LLPT is distinct
from the liquid-to-ice transition in ST2 water. We also present evidence that throughout the
supercooled region, including near the melting line, small subcritical ice nuclei are
surrounded by a significant region of low density liquid, which grows in extent as the LLPT is
approached. This observation supports the view [6] that low density liquid fluctuations play
an important role in the early stages of ice formation.
REFERENCES
1. Palmer, J.C., Martelli, F., Liu, Y., Car, R., Panagiotopoulos, A. Z., and Debenedetti, P.G., Nature. 510, 385
(2014).
2. Poole, P.H., Bowles, R.K., Saika-Voivod, I., and Sciortino, F., J. Chem. Phys. 138, 034505 (2013).
3. Smallenburg, F., Poole, P.H., and Sciortino, F., Molecular Physics. 113, 2791 (2015).
4. Buhariwalla, C.R.C.. Bowles, R.K.. Saika-Voivod, I., Sciortino, F., and Poole, P.H., Eur. Phys. J. E 38, 39
(2015).
5. Morris, S.K., Zavalov, O., Bowles, R.K., Saika-Voivod, I., Sciortino, F., and Poole, P.H., in preparation
(2017).
6. Moore E.B., and Molinero, V., Nature. 479, 506 (2011).
ORAL CONTRIBUTIONS Water-HB-9
Invited Talk
An NMR study on the hydrophilic and hydrophobic
interactions
(From methanol to protein water solutions).
Francesco Mallamace, Carmelo Corsaro, Sebastiano Vasi, Sow-Hsin Chen, H.
Eugene Stanley and Domenico Mallamace
MIFT Department, Section Physics, Università di Messina, CNR-IPCF, I-98166, Messina,
Italy,NSE Department; Massachusetts Institute of Technology Cambridge, Boston University,
Physics Department USA and CSGI Florence Italy.
Using nuclear magnetic resonance (NMR) we study the dynamics of the hydrogen bond (HB)
sub-domains in bulk and emulsified water across a wide temperature range that includes the
super-cooled regime. We measure the proton spin-lattice T₁ and spin-spin T₂ relaxation times
to understand the hydrophilic interactions that determine the properties of water. We use (i)
the Bloembergen, Purcell and Pound (BPP) approach that focuses on a characteristic
correlation time C, and (ii) the Powles and Hubbard (PH) approach that measures the proton
rotational time . We find that when the temperature is low both relaxation times are strongly
correlated when the HB lifetime is long, and that when the temperature is high a decrease in
the HB lifetime destroys the water clusters and decouples the dynamic modes of the system.
Lately in the same theoretical approaches we study pure bulk methanol and the corresponding
water solutions in a large concentration range (methanol molar fractions) from the stable to
the super-cooled regimes. Our findings are: i) a separate characterization of the hydrophilic
and hydrophobic interactions and the corresponding dynamics; ii) whereas the hydrophilicity
dominates the solution chemical physics in the water super-cooled phase, the hydrophobicity
governs it by increasing temperature from a crossover value located at about 265K, where the
HB lifetime is of the order of some picoseconds. Such a situation is of strong relevance for
more complex materials such as polymeric systems and biological macromolecules like
peptides and proteins especially for their thermal configuration changes.
Water-HB-10 ORAL CONTRIBUTIONS
Invited Talk
Water between Buckyballs and Alcohols on Graphenes
Ronen Zangi
Polymat & Department of Organic Chemistry, University of the Basque Country
(UPV/EHU), San Sebastian, Spain
In this talk, I will present molecular dynamics simulations results of hydrogen bonded
systems in contact with carbon based structures. In particular, arguments challenging the
common view that the interaction between buckyballs in aqueous solution is hydrophobic will
be presented. The reason for this counterintuitive claim is the shape of the contact state, that
supports the existence of a unique type of interfacial waters located between two convex
surfaces of two buckyballs. Furthermore, results on the structure formed by several alcohols
adsorbed on graphene will be discussed. In this case two structural elements, strings and
rings, characterize the ordering of the liquid phase and give rise to different phases in the
system. The transition from rings to strings can be induced by lowering the temperature or by
increasing the density. Strings of alcohols can undergo another transition upon cooling; here,
the order–disorder transition is identified by a low-temperature phase in which the hydrogen
bond dipoles of neighboring strings adopt an antiparallel orientation.
REFERENCES
1. Zangi, R., Are Buckyballs Hydrophobic?, J. Phys. Chem. B, 118, 12263-12270 (2014).
2. Zangi, R., Roccatano, D., Strings-to-Rings Transition and Antiparallel Dipole Alignment in Two-
Dimensional Methanols, Nano Lett. 16, 3142-3147 (2016).
ORAL CONTRIBUTIONS Water-HB-11
Invited Talk
Understanding of adsorption of water and hydrogen in
porous materials at nanoscale – neutron scattering insight.
Margarita Russina
Helmholtz Zentrum Berlin, Hahn-Meitner Platz 1, 14109 Berlin Germany
The adsorption of liquid and gasses, particularly hydrogen and water, is important for many
areas of science and applications ranging from energy storage for hydrogen economy to
transport phenomena in geology and biology. In this context, the understanding of hydrogen
bonds formation in various environment and criteria governing the molecular mobility at
nanoscale is of high importance. Using neutron scattering as a powerful magnifying glass we
have investigated molecular structure and dynamics of hydrogen and water as an example of
non-polar and polar molecules in confinement. By an aimed selection of the confining
systems, we were able to systematically follow the molecular behavior in pores of various
sizes and shapes and in environments with variable degrees of guest-host interactions. We
observe that in systems with weak guest-host interactions the molecular mobility depends
non-linearly from the confinement size. With an increase of guest-host interactions, we see
the onset of adsorption induced changes of the host structure and the formation of new
structural phases of guest molecules. These molecular scale phenomena ultimately control
macroscopic properties such as sorption storage capacity, isotherm behavior etc.
REFERENCES
1. Kurig, H., Russina, M., Tallo, I., Siebenbürger, M., Romann, T., E. Lust, Carbon. 100 (2016) 617-624
2. Russina, M., et al, Sci. Rep. 6, 27417; doi: 10.1038/srep27417 (2016).
3. Schlegel, M. C., Russina, M., et al, PCCP. 2016, DOI: 10.1039/C6CP05310F
Water-HB-12 ORAL CONTRIBUTIONS
Invited Talk
New Insights into the Low-temperature Dynamics of Ice
Christoph G. Salzmann, Jacob J. Shephard
University College London, Department of Chemistry, 20 Gordon Street, London WC1H
0AJ, United Kingdom
The water molecule displays enormous complexity in its condensed phases both in terms of
structural diversity as well as dynamic processes. Understanding H2O at low temperature is
important with respect to a vast range of critical processes in geology, biology, chemistry, the
atmospheric sciences and space research.[1]
The glass transitions of low-density amorphous ice (LDA) and high-density amorphous ice
(HDA) are the topic of controversial discussions. We first show that the glass transition of
hydrogen-disordered ice VI is associated with the kinetic unfreezing of molecular
reorientation dynamics by measuring the calorimetric responses of the corresponding H2O,
H218
O and D2O materials in combination with X-ray diffraction. Well-relaxed LDA and HDA
show identical isotopic-response patterns in calorimetry as ice VI, and we conclude that the
glass transitions of the amorphous ices are also governed by molecular reorientation
processes.[2] This ‘reorientation scenario’ seems to resolve the previously conflicting
viewpoints and is consistent with the fragile to strong transition from water to the amorphous
ices.
The structural nature of high-density amorphous ice (HDA), which forms through low-
temperature pressure-induced amorphization of the ‘ordinary’ ice I, is also heavily debated.
We show that ammonium fluoride (NH4F), which has a similar hydrogen-bonded network to
ice I, also undergoes a pressure collapse upon compression at 77 K. However, the product
material is not amorphous but NH4F II, a high-pressure phase isostructural with ice IV. This
collapse can be rationalized in terms of a highly effective mechanism. In the case of ice I, the
orientational disorder of the water molecules leads to a deviation from this mechanism and we
therefore classify HDA as a ‘derailed’ state along the ice I to ice IV pathway.[3]
REFERENCES
1. Salzmann, C.G., Radaelli, P.G., Slater, B., Finney, J.L., The Polymorphism of Ice: Five Unresolved
Questions, Phys. Chem. Chem. Phys., 13, 18468-18480 (2011).
2. Shephard, J.J.,Salzmann, C.G., Molecular Reorientation Dynamics Govern the Glass Transitions of the
Amorphous Ices, J. Phys. Chem. Lett., 7, 2281-2285 (2016).
3. Shephard, J.J., Ling, S., Sosso, G.C., Michaelides, A., Slater, B., Salzmann, C.G., Is High-Density
Amorphous Ice Simply a “Derailed” State along the Ice I to Ice IV Pathway?, J. Phys. Chem. Lett. 8, 1645-
1650 (2017).
ORAL CONTRIBUTIONS Water-HB-13
Invited talk
Anomalies in Water enlighten those in molten Te and Phase
Change Materials (PCM) chalcogenides
C. Austen Angella, Shuai Wei
a,b, and Pierre Lucas
c
aSchool of Molecular Sciences, Arizona State University, Tempe AZ, 85287-1604 USA,
b Aachen University I. Physikalisches Institut, Sommerfeldstr. 14, C52074 Aachen, Germany
c Dept. of Materials Science and Engineering, Univ. of Arizona, Tucson, AZ 85721, USA
Liquid water has long held the mantle of "Most anomalous liquid" because of its bizarre
behavior in the liquid state, particularly under supercooling1. Despite contrary opinions, its
diverging response functions and relaxation times are widely believed to be due to close
approach to a second critical point, this time between two liquids of different density. Direct
confirmation by laboratory studies has been precluded by diverging ice crystallization rates
that develop as the critical domain is approached.
Recently however, not only have other tetrahedral liquids been shown to have similar
behavior (at least liquid silicon2 and some silica models
3,4) but related phenomena (fragile-to-
strong liquid transitions) and density maxima in liquid Te5 and Te85Ge15
6 and (by
extrapolation) in liquid PCM chalcogenides7, have led to the suggestion that a fast liquid-
liquid phase change might be acting as an "Ostwald stage" to the crystallization process that
is fundamental to the action of the PCMs8
In this talk, we will review the experimental findings that lie behind the above commentary,
including the existence of melting point maxima in water and Te (on opposite sides of the
zero pressure mark), and discuss some recent successful strategies for revealing the seminal
liquid-liquid event in the case of aqueous systems9.
Finally we look into the possibility of
applying similar strategies to the elucidation of what might be going on in the PCM systems
where the LL transitions are also (tunable) metal-semiconductor transitions that, in other
composition ranges, are often observable above the melting points.
REFERENCES
1. Gallo, P., Petterssen, L.G.M., et al. Chem. Rev. 116, 7463-7500 (2016)
2. Sastry, S., Angell, C. A., Nature Materials. 2, 739-743 (2003)
3. Lascaris, E., Hemmati, M., Buldyrev, S.V., Stanley, H.E., Angell, C.A.. J. Chem. P. 140, 224502 (2016)
4. Lascaris, E., Phys. Rev. Lett. 116, 125701 (2016)
5. Kanno. H., Yokoyama, H., Yoshimura, Y. J., Phys. Chem. B. 105, 2019 (2001).
6. Wei, S., Lucas, P., Angell, C. A., J. Appl. Phys. 118, 034903 (2015).
7. Kalb, J. A., Wuttig, M., Spaepen, F., J. Mater. Res. 22, 748-754 (2007).
8. Wei, S., Lucas, P., Angell, C. A., Phys. Rev. Applied, 7 (3), 034035 (2017)
9. Shao Z.-F., Angell, C. A., Angew. Chem. Int. Ed. 128 (7), 2520-2523 (2016)
Water-HB-14 ORAL CONTRIBUTIONS
Invited Talk
The non-Arrhenius-Arrhenius transition in polymer
solution is the unique to water or not
Naoki Shinyashiki*, Kenta Bandai
*, Masanobu Takatsuka
*, Kaito Sasaki
+,
Rio Kita*+
, Shin Yagihara*
Department of Physics, School of Science* and Micro/Nano Technology Center+
Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan
One of the most attractive phenomena of water dynamics from the glassy state of water to its
liquid state is the non-Arrhenius-Arrhenius transition (non-AA transition), so-called fragile-
to-strong transition (FST) of water. The non-AA transition of water dynamics has been
observed universally for various kinds of aqueous systems1-6
.
To answer the question whether the non-AA transition is the unique to water or not,
broadband dielectric spectroscopy measurements were performed for poly(vinylpyrrolidone)
(PVP)-water, PVP-propylene glycol, PVP-ethylene glycol, and PVP-propanol mixtures with
65 wt. % of PVP in a temperature range of 123−318 K. For the PVP-water mixture, two
distinct relaxation processes originate from the segmental chain motion of PVP (-process of
PVP) and the primary relaxation process of water, respectively, are observed simultaneously6.
The temperature dependence of the relaxation time of the water process exhibits a non-AA
crossover at the glass transition temperature, Tg, of the -process of PVP6. On the other hand,
the crossover of the relaxation process of alcohol at Tg of the -process of PVP in alcohol-
PVP mixtures is completely different from that observed in PVP-water mixture.
REFERENCES
1. Shinyashiki, N., Sudo, S., Yagihara, S., Spanoudaki, A., Kyritsis, A., Pissis, P., Relaxation Processes of
Water in the Liquid to Glassy States of Water Mixtures Studied by Broadband Dielectric Spectroscopy, J.
Phys.: Condens. Matter, 19, 205113 (12pp) (2007).
2. Capaccioli, S., Ngai, K. L., Shinyashiki, N., The Johari-Goldstein â-Relaxation of Water, J. Phys. Chem. B.
111, 8197-8209 (2008)
3. Shinyashiki, N., “Dynamics and Glass Transition of Aqueous Solutions of Molecular Liquids, Polymer, and
Protein Studied by Broadband Dielectric Spectroscopy” in Nano/Micro Science and Technology in
Biorheology - Principles, Methods, and Applications -, Edited by R. Kita, T. Dobashi, Springer, 215-237,
(2015).
4. Cerveny, S., Mallamace, F., Swenson, J., Vogel, M., Xu, L., Confined Water as Model of Supercooled
Water, Chem. Rev. 116, 7608-7625 (2016).
5. Cerveny, S., Alegría, Á., Colmenero, J., Broadband dielectric investigation on poly (vinyl pyrrolidone) and
its water mixtures, J. Chem. Phys. 128, 044901-1-7 (2008)
6. Sasaki, K., Matsui, Y., Miyara, M., Kita, R., Shinyashiki, N., Yagihara, S., Glass Transition and Dynamics
of the Polymer and Water in the Poly(vinyl pyrrolidone)-Water Mixtures Studied by Dielectric Relaxation
Spectroscopy, J. Phys. Chem. B. 120, 6882-6889(2016).
ORAL CONTRIBUTIONS Water-HB-15
Invited Talk
Glucose and mannose: a link between hydration and
sweetness
M. A. Ricci1, F. Bruni
1, S. Imberti
2, S. E. McLain
3, N. Rhys
3
1 Dipartimento di Scienze, Universita Roma Tre, Roma, Italy
2 STFC, Rutherford Appleton Laboratory, ISIS facility, Didcot, UK
3 Department of Biochemistry, University of Oxford, Oxford, UK
Among our senses, taste has the primary function of driving our appetite, protecting from poisons and
contributing to the overall enjoyment of a meal. Sweet taste permits the identification of energy-rich
nutrients, umami allows the recognition of amino acids, salt taste ensures the proper dietary electrolyte
balance, and sour and bitter warn against the intake of potentially poisonous chemicals. In particular
the perception of sweet or bitter taste is ascribed to taste receptor cells expressing T1R2+T1R3 or T2R
receptors which, after binding to the sweet or bitter molecule, activate Guanine proteins for signal
transmission to the brain [1]. What is still debated is why a sugar is perceived sweeter than another or
elicits a bitter aftertaste. This is a quite intriguing question, given that substantial taste differences
seem to be determined by apparently small differences in the molecular stereochemistry of sugars: the
case of mannose is paradigmatic as α- mannose is sweet while its anomer β-mannose is bitter [2, 3].
A solid molecular theory of the sweet taste is still lacking and the best model available is the so-called
sweetness triangle [4, 5] and its evolution, namely the multipoint interaction model [6]. Both models
establish a relation between molecular structure and taste, by requiring the presence of specific
Hydrogen bond donor and acceptor sites, plus a hydrophobic or steric hindrance. This structural
characteristics can be verified by determining the hydration properties of sugars.
In this communication we present the results of neutron diffraction experiments on two
monosaccharides, showing the correlation between the number and directionality of the Hydrogen
bonds formed with water and the degree of sweetness of the sugars.
REFERENCES
1. Chandrashekar, J., et al., The receptors and cells for mammalian taste, Nature. 444, 288-294 (2006).
2. Steinhardt, R. G. Jr, et al., Taste-structure correlation with α-D- mannose and β-D-mannose, Science. 135,
367-8 (1962).
3. Stewart, R. A., et al., Physicochemical Stere- ospecificity in Taste Perception of α−D-Mannose and β−D-
Mannose, Nature. 234, 220, (1971).
4. Shallenberger, R. S., Acree, T. E, Molecular Theory of Sweet Taste, Nature. 216, 480-482 (1967).
5. Kier, L. B. A, Molecular Theory of Sweet Taste, J. Pharmaceutical Sci. 61, 1394- 1397 (1972).
6. Nofre, C., Tinti, J.-M., Sweetness reception in man: the multipoint attachment theory, Food Chemistry, 56,
263-27 (1996).
Water-HB-16 ORAL CONTRIBUTIONS
Invited Talk
Fragile to Strong Crossovers of supercooled water: origin
and possible experimental measurements
Paola Gallo
Dipartimento di Matematica e Fisica, Università Roma Tre
Via della Vasca Navale 84, 00146 Roma Italy.
A dynamic crossover from a fragile behaviour to a strong behaviour happens in many simple
glass formers upon supercooling. In water this crossover, observed in translational relaxation
time, has been connected to its thermodynamics and in particular to the possible existence of a
liquid-liquid critical point. It was observed in experiments on confined water and hydration
water, in simulations on bulk water, confined water, hydration water and in aqueous solutions
at low concentrations. Very recently it was also observed in an experiment on bulk water. I
will show results from molecular dynamics simulations that focus on two connected issues.
The first is on the microscopic origin of this behaviour. I will show results from an analysis of
the density correlators of TIP4P/2005 water on approaching the region of the liquid-liquid
critical point [1]. The the van Hove self correlation functions clearly show that in the strong
supercooled regime activated (hopping) processes dominate the dynamics. A comparison
between the van Hove functions and the Radial Distribution Functions allows to better
understand the mechanism of hopping in supercooled water and to connect their onset directly
with the crossing of the Widom Line. The second issue is on the possibility of measuring such
crossover. I will show the radial distribution functions upon supercooling of water confined in
a silica pore [2]. The two body excess entropy is calculated from the radial distribution
functions. I will show that the two body entropy changes its behavior in coincidence with the
crossover of the relaxation time from the fragile to the strong regime. As for bulk water also
in confinement, the two body entropy has a strict connection with the dynamic relaxations and
the experimental measurements of the radial distribution function of confined water as
function of temperature can more easily probe the fragile to strong transition.
REFERENCES
1. De Marzio, M., Camisasca, G., Rovere, M., and Gallo, P., Microscopic origin of the Fragile to Strong
Crossover in Supercooled Water: the role of Activated Processes, J. Chem. Phys. 146, 084502 (2017).
2. De Marzio, M., Camisasca, G., Martin Conde, M., Rovere, M., and Gallo, P., Structural properties and
fragile to strong transition in confined water, J. Chem. Phys. 146, 084505 (2017). Press release by AIP
entitled: "Exploring the Mysteries of Supercooled Water".
ORAL CONTRIBUTIONS Water-HB-17
Invited Talk
Hydrogen Bonding in Aqueous Solutions and Confinement
Induced Micro-phase Separation
Jan Swensona, Khalid Elamin
a, Christoffer Olsson
a and Helén Jansson
b
aDepartment of Physics, Chalmers University of Technology, SE-412 96 Göteborg Sweden
bDepartment of Civil and Environmental Engineering, Chalmers University of Technology,
SE-412 96 Göteborg Sweden
We present structural and dynamical results of aqueous solutions, with a specific focus on
solutions confined in 2-3 nm pores of MCM-41. Experimental data from differential scanning
calorimetry, dielectric spectroscopy and quasielastic neutron scattering show strong support
for that aqueous alcohol solutions become micro-phase separated in the pores, due to the
preference of water molecules to coordinate to the hydroxyl surface groups of the pores [1-3].
This results in a lower water concentration in the centre of the pores and an anomalous
concentration dependence of the dynamics compared to the corresponding bulk solution [1-3].
There are also indications of that the alcohol molecules break up the tetrahedral structure of
water at low temperatures and high water contents, and thereby act as a plasticizer [1].
We have also studied the structural properties of trehalose-water solutions using neutron
diffraction and Empirical Potential Structure Refinement (EPSR) modelling. The results show
that the water structure is significantly perturbed by the presence of trehalose, and that water
forms extensive hydrogen bonding with trehalose [4]. Primarily, water binds to the hydroxyl
groups of trehalose, and particularly to the hydroxyl groups on the methyl groups. Another
important finding is that the trehalose molecules are homogeneously dispersed in the water
with no preference of forming clusters, which are commonly observed in molecular dynamics
simulations of this solution [4]. In fact, the trehalose molecules are less clustered than in a
completely random distribution of the trehalose molecules in water. The insights are helpful
for understanding the extraordinary stabilizing effect of trehalose on biological materials.
REFERENCES
1. Elamin, K. et al. Different Behaviour of Water in Confined Solutions of High and Low Solute
Concentrations, Phys. Chem. Chem. Phys. 15, 18437-18444 (2013).
2. Elamin, K., JANSSON, H., SWENSON, J. Dynamics of Aqueous Binary Glass-Formers Confined in MCM-
41. Phys. Chem. Chem. Phys. 17, 12978-12987 (2015).
3. Swenson, J. et al. Anomalous Dynamics of Aqueous Solutions of Di-Propylene Glycol Methylether
Confined in MCM-41 by Quasielastic Neutron Scattering. J. Chem. Phys. 141, 214501 (2014).
4. Olsson, C. et al. Structure of Aqueous Trehalose Solution by Neutron Diffraction and Structural Modeling.
J. Phys. Chem. B. 120, 12669-12678 (2016).
Water-HB-18 ORAL CONTRIBUTIONS
Invited Talk
The behavior of water in the ultra-confinement of natural
minerals
Paul Ben Ishai
Department of Physics, Ariel University, Ariel, Israel
What would happen if the H-bond was removed from water, even though water was not in a
gaseous state? Certainly, its delinquent anomalous behavior would be absent, but so would be
the collective phenomena that make it so unique. This situation can be approached when
water molecules are ultra-confined in sub-nanometer sized channels, present in natural
minerals, such as cordierite. These channels are an integral part of the crystal lattice. The
diameter is often of the same order of magnitude as the diameter of a water molecule, 4-5 Å.
Under such conditions water entrapped in them at the time of formation, but not chemically
bound, can no longer behave as “water”. But rather than conform, these extreme conditions
lead to unusual behaviours. Concepts like H-bonding and clustering are now not relevant and
a new class of dynamics must arise for these molecules. These crystals are, per force, highly
anisotropic, leading to very different dielectric properties depending of the crystal axis
chosen. DC conductivity is sometimes present, but not necessarily along the water channels.
Surprisingly, despite the absence of H-bonds water still exhibits cooperative features in its
dielectric response, such a glass transition. This, and other phenomena will form the basis of
this presentation.
ORAL CONTRIBUTIONS Water-HB-19
Oral
Structural dynamics in formamide-water mixtures
investigated by UV Raman spectroscopy
B. Rossia, M. Paolantoni
b, F. D’Amico
a, C. Bottari
a, A. Gessini
a, C.
Masciovecchioa
a Elettra - Sincrotrone Trieste, Strada Statale 14 km 163.5, 34149 Trieste, Italy
b Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, Via Elce di Sotto
8, I-06123 Perugia, Italy
Formamide (FA) is the simplest molecule that contains a peptide bond and FA-water
solutions can represent a relatively simple model for the study of basic aspects of hydrogen
bonding interactions involving water and amide groups. It is known that these interactions
play important roles in a wide variety of bio-relevant processes, such as protein hydration,
folding and aggregation. The intermolecular structure of formamide has been the subject of
several theoretical and experimental studies that suggest the existence, in the liquid state, of
an extended hydrogen bond (HB) network with some similarities with the network occurring
in liquid water [1,2]. For these reasons, the study of the intermolecular structure and dynamics
of FA-water mixtures have received a great deal of attention [3,4].
In this contribution, the intermolecular structure and its dynamical rearrangement in FA-water
solutions have been investigated as a function of concentration and temperature by means of
UV Raman scattering experiments with different excitation wavelengths. In particular, both
polarized and depolarized Raman profiles have been collected at ca. 260 nm and the spectra
have been deeply analysed in order to extract insights on the hydrogen bond restructuring.
Particular attention has been devoted to the study of concentration-dependent aggregation
features. Moreover, thermal effects on the FA vibrational bands in water-rich mixtures, have
been investigated; in these conditions FA-FA interactions can be neglected and the structural
dynamics of FA mainly depends on its interactions with surrounding water molecules.
Overall, these experiments provide relevant insights on the intermolecular structure and the
molecular dynamics occurring in these associating liquid mixtures strongly influenced by the
formation and the reorganization of H-bonds involving two bio-relevant species.
REFERENCES
1. Jadzyn, J., Swiergiel, J., Phys. Chem. Chem. Phys. 14, 3170-3175 (2012).
2. Tsuchida, E., J. Chem. Phys. 121, 4740 (2004).
3. Elola, M. D., Ladanyi, B. M., J. Chem. Phys. 126, 084504 (2007).
4. Elola, M. D., Ladanyi, B. M., J. Chem. Phys. 125, 184506 (2006).
Water-HB-20 ORAL CONTRIBUTIONS
Oral
Structural dynamics of hydration water in cyclodextrin
aqueous solutions
C.Bottaria,b
, B.Rossia, L.Comez
c, S.Corezzi
d, M.Paolantoni
e, F.D’Amico
a,
A.Gessinia, C.Masciovecchio
a
aElettra-Sincrotrone Trieste, S.S. 114 km 163.5, Basovizza, 34149, Trieste, Italy
bDepartment of Physics, University of Trieste, Via A. Valerio 2, 34127, Trieste, Italy
cIOM-CNR c/o Department of Physics and Geology, University of Perugia, Via A. Pascoli,
06123 Perugia, Italy
dDepartment of Physics and Geology, University of Perugia, Via A. Pascoli, 06123 Perugia,
Italy
eDepartment of Chemistry, Biology and Biotechnology, University of Perugia, Via Elce di
Sotto 8, I-06123 Perugia, Italy
The investigation of structural and dynamical properties of aqueous solutions of sugars is one of the
fundamental topic to increase the knowledge of important biological systems.
In order to achieve a comprehensive view of the mechanisms that drive the solvation dynamics of
biomolecules, it is possible to employ different experimental techniques able to probe the time scales
characterizing the molecular restructuring processes occurring in these systems. In this contribution,
we will show how the joint use of UV Raman and Brillouin spectroscopy can be used in a
complementary way to study the solute-solvent interactions and the hydration shell structural
properties in aqueous solutions of cyclodextrins (CD). CD are natural cyclic oligosaccharides well
known for their properties of molecular host systems that have found in these years many industrial
uses in the food, cosmetic and pharmaceutical field. Water plays an important role in determining the
complexation ability exhibited by CD towards different types of guest compounds since the molecular
encapsulation capability of CD is directly related to the solvation properties of these complex sugars.
UV Raman and Brillouin scattering experiments have been used to investigate aqueous solutions of
natural and chemically modified CD, giving insights into the structural dynamics of different
hydrogen-bond (HB) species, as a function of temperature and solute concentration. Spectral changes
in the Raman signal are used as vibrational signatures of reorganization of the HB network of water in
the proximity of groups of CD. In a complementary way, visible and UV Brillouin scattering
experiments are used to probe the collective dynamics of the systems on the timescale 0.1–10 ps,
characteristic associated to the average timescale of the intermolecular bonds lifetime, typically
observed in liquid HB systems. The overall results presented here corroborate the potentiality of the
joint use of inelastic scattering techniques to provide a comprehensive molecular view on the solvation
dynamics in water-sugar solutions.
ORAL CONTRIBUTIONS Water-HB-21
Oral
Probing the equation of state of deeply supercooled
TIP4P/2005 water with nanodroplets
S.M. Malek1, P.H. Poole
2, I. Saika-Voivod
3
1Department of Physics and Physical Oceanography,
Memorial University of Newfoundland, St. John’s, NL, Canada
2Department of Physics, St. Francis Xavier University, Antigonish, NS, Canada
We carry out extensive molecular dynamics (MD) simulations to study the equilibrium
properties of water nanodroplets modelled with the TIP4P/2005 potential. We study a range
of droplet sizes from N =64 to 2880 with temperatures ranging from T =180 K to 300 K. At
low temperatures, we run an ensemble of ∼1000 MD simulations at individual state points to
calculate equilibrium properties. We find that the droplet must be of size greater than 360
molecules to show anomalous density behaviour, i.e., droplet expansion on cooling. We
calculate the local density and pressure in the droplets at all N and T . Owing to the Laplace
pressure, for sufficiently small droplets, the density inside the droplet exceeds the density of
water at the liquid-liquid critical point proposed for the model. With nucleation suppressed by
small system size, we find the equation of state for the liquid in droplet form and compare it
to that of bulk water. The comparison yields a quantitative measure of the effectiveness of
using nanodroplets to probe the existence of a metastable liquid-liquid critical point and
associated anomalies.
POSTER
CONTRIBUTIONS
POSTER P-1
Theor-Simul
Quasi-universality and the EXP pair potential
Andreas K. Bacher and Jeppe C. Dyre
Roskilde University, Universitetsvej 1, Postbox 280, 4000 Roskilde, Denmark
The quasi-universality class consists of systems of particles interacting with pair potentials
that can be written as a sum of exponentially repulsive pair potentials (EXP) from the region
of the phase diagram of the EXP pair potential with strong correlations between fluctuations
in the potential energy and the virial [1]. Systems of particles interacting by a EXP pair
potential has no gas-liquid phase transition because s there are no attractive forces between
the particles. Thus, only a crystalline and a fluid state exist [2]. Since the EXP pair potential
plays a central role in defining quasi-universality, an investigation of its properties has been
conducted. Results so far has revealed, e.g., that the strong correlations found in the low-
temperature part of the thermodynamic phase diagram sustain even into the low-density (gas-
like) region, and that isomorphs exist which can be approximated by different methods – one
yielding analytical expressions. Interestingly, the slope of the isomorphs is controlled by
temperature in the low-density region and not by density, as usually seen. This can be
understood as the single pair-interactions dominating the contributions to the fluctuations in
the potential energy and the virial, not the collective forces as is normally the case. An
implication of our finding is that many systems conform to the isomorph theory and thus
belong to the class of quasi-universal systems.
REFERENCES
1. Bacher, A. K., Schrøder, T. B., & Dyre, J. C., Explaining why simple liquids are quasi-universal. Nat.
Comm. 5, 5424 (2014)
2. Bacher, A. K., and Dyre, J. C., The mother of all pair potentials. Colloid Polym. Sci. 292, 1971-1975
P-2 POSTER
Theor-Simul
Molecular dynamics simulations of water-like models from
supercooled to superheated temperatures
Horstmann, Robin1; Vogel, Michael
1
(1) Technische Universität Darmstadt
The very general slowdown of molecular dynamics in glass-forming liquids is still not well
understood. Studies often focus on the supercooled regime and compare very different
molecules. We employ a different approach. We create families of water-like molecules by
systematically varying the partial charges of established water models (SPC/E and
TIP4P2005) by up to 25%. While the molecular properties, except for the dipole moment,
stay unchanged, the inter-molecular interactions of the models vary strongly. Exploring broad
temperature ranges, from superheated Arrhenius regime to supercooled super–Arrhenius
regime, we study the structure and dynamics of these families. The resulting dynamics spread
over a large temperature range with the glass transition temperature Tg and the high
temperature activation energy E∞ both changing by a factor of 5.
A recently proposed empirical function proves useful for describing the structural relaxation
in the complete temperature range [1]. It is observed that, despite their large dynamical
diversity, all water-like models show general relations between E∞ and the cooperative
contribution to the activation energy, EC(T), in the supercooled regime, implying a close link
between the high-temperature and low-temperature dynamics. Moreover, links between short-
time and long-time motions are found and analyzed in terms of elastic models. The fact that
the members of the studied families share the same molecular structure and differ only with
respect to a single parameter, the molecular dipole moment, allows for in depth analyses.
REFERENCES
1. Schmidtke, B. et al., "From boiling point to glass transition temperature: Transport coefficients in
molecular liquids follow three-parameter scaling", Phys. Rev. E 86.4 (2012): 041507.
POSTER P-3
Theor-Simul
Investigation and theoretical modeling of polystyrene glass
transition in a wide range of cooling rates
T.V. Tropin1, J.W.P. Schmelzer
2,1, C. Schick
2, V.L. Aksenov
3,1
1 Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
2 Institute für Physik der Universität Rostock, Rostock, Germany
3 National Research Centre “Kurchatov Institute”, Moscow, Russia
The formulation of a complete theory of the glass transition remains one of the challenges for
the modern physics [1]. This is one of the reasons of the continuing interest in analysis of
these problems. In addition, also from a practical viewpoint, experimental study and
theoretical description of glass transition are very important topics, due to the wide
distribution of modern technological applications of glasses as well as their frequent
occurrences in everyday life.
Polymers are known to be good glass formers, allowing one to study glass transition effects as
well as to verify the applicability of various theoretical models. In the presented work
experimental and theoretical investigations of glass transition of atactic polystyrene (PS) in a
broad range of cooling rates (5·10-6
-2 K/s) were performed [2]. The capability of commonly
employed theoretical techniques for Cp modeling to describe the obtained data is considered.
It is shown that the extended Tool-Narayanaswamy-Moynihan (TNM) model with Vogel-
Fulcher-Tammann-Hesse (VFTH) or Adam-Gibbs (AG) expressions for relaxation time with
the common single set of parameters do not fit the experimental data well. Moreover, the
values of parameters required to produce an adequate fit of the whole set of heating curves are
quite different from their estimates obtained from independent additional experiments. An
additional expression for relaxation time is proposed within the Gutzow-Schmelzer (GS)
approach for describing the kinetics of glass transition leading to results of similar precision.
The obtained results reconfirm the general conclusion that the considered models of glass
transition require parameter readjusting for different cooling or heating rates in order to
adequately describe the experimental data.
REFERENCES
1. Berthier, L., Biroli, G., Theoretical perspective on the glass transition and amorphous materials, Rev. Mod.
Phys. 83 587–645 (2011).
2. Tropin, T. V., Schulz, G., Schmelzer, J.W.P., Schick, C., Heat capacity measurements and modeling of
polystyrene glass transition in a wide range of cooling rates, J. Non. Cryst. Solids. 409 63–75 (2015).
P-4 POSTER
Nonlin-Dyn
Effect of nematic ordering on the elasticity and yielding in
disordered polymeric solids
A. Giuntoli1, N. Calonaci
2, S. Bernini
1, D. Leporini
1,3
1Dipartimento di Fisica “Enrico Fermi”, Università di Pisa, Italy
2International School for Advanced Studies (SISSA), Trieste, Italy
3Istituto per i Processi Chimico-Fisici-Consiglio Nazionale delle Ricerche, Pisa, Italy
The relation between elasticity and yielding is investigated in a model polymer solid by
Molecular-Dynamics simulations. By changing the chain flexibility and the bond length,
crystals and glasses - both with bond disorder - and nematic glasses are obtained. It is found
that in systems with bond disorder the ratio τY /G between the shear yield strength τY and the
shear modulus G is, within the errors, equal to the universal value of the atomic metallic
glasses1. The increase of the local nematic order in disordered glasses leads to the increase of
the shear modulus and the decrease of the shear yield strength.
REFERENCES
1. JOHNSON, W. L.; SAMWER, K., A Universal Criterion for Plastic Yielding of Metallic Glasses with a
(T/Tg)2/3
Temperature Dependence, Phys. Rev. Lett. 95, 195501 (2005).
POSTER P-5
Nonlin-Dyn
Transport Phenomena of Spatiotemporal Chaos in
Electroconvective Systems of Nematic Liquid Crystal
T. Narumi1, J. Yoshitani
2, Y. Mikami
2, H. Okabe
2, K. Hara
2, and Y. Hidaka
2
1Yamaguchi University, Ube, Japan,
2Kyushu University, Fukuoka, Japan
Convective systems have been studied as an example of chaos in dissipative systems; in
particular, weak turbulence in spatially extended systems can be regarded as spatiotemporal
chaos. Of current interest is how turbulence affects transport phenomena. Here, by regarding
disorder of weak turbulence as nonthermal fluctuations, we analyze the transport phenomena
of spatiotemporal chaos in systems of nematic liquid crystals.
Electroconvection of nematic liquid crystals has been studied as a suitable experimental
system because it can be prepared with large degrees of freedom and a short response time.
Some types of spatiotemporal chaos appear in electroconvective systems of nematic liquid
crystals, and we here deal with two of them: defect turbulence (DT) and soft-mode turbulence
(SMT). Since DT and SMT appear under the same experimental conditions except for
molecular alignment, one can systematically investigate the diversity and also the universality
of spatiotemporal chaos.
Our analytical approach to the nonthermal fluctuations is the projection operator method for
chaos and turbulence, which can separate turbulent transport into a macroscopic contribution
and fluctuations. In SMT, we observed the relaxation that shows the dual structure, i.e., the
dynamic crossover accompanied by the violation of the macroscopic time-reversal invariance
[1]. By employing the projection operator method, the dual structure has been elucidated from
the nonthermal fluctuations relating to so-called patch structure, an intermediate-scale spatial
structure. On the other hand, in DT, we observed the relaxation that exhibits decay with a
long-term oscillation [2]. The dynamics has been clarified as the combination of the roll
modulation and the repetitive gliding of defect pairs in a local area. Further, the projection
operator method has revealed that the nonthermal fluctuations of DT can be separated into
two independent Markov fluctuations.
REFERENCES
1. Narumi T., Yoshitani J., Suzuki M., Hidaka Y., Nugroho F., Nagaya T., and Kai S., “Memory function of
turbulent fluctuations in soft-mode turbulence,” Phys. Rev. E 87, 012505 (2013).
2. Narumi T., Mikami Y., Nagaya T., Okabe H., Hara K., and Hidaka Y., “Relaxation with long-period
oscillation in defect turbulence of planar nematic liquid crystals,” Phys. Rev. E 94, 042701 (2016).
P-6 POSTER
Poster nonlin
Creep, failure and shear banding in a phase separating
system
F. Puosi,1
K. Martens,2 J.-L. Barrat,
2,3 L. Berthier
4
1 Sciences et Ingénierie des Matériaux et Procédés, UMR 5266 CNRS, Université Grenoble
Alpes, (UGA), 1130 rue de la Piscine, BP 75, 38402 Saint-Martin d’Hères Cedex, France
2 Univ. Grenoble Alpes, CNRS, LIPHY, F-38000 Grenoble, France.
3 Institut Laue-Langevin, 6 rue Jules Horowitz, BP 156, F-38042 Grenoble, France.
4 Laboratoire Charles Coulomb, UMR 5221 CNRS-Universit de Montpellier, Montpellier,
France.
In this work, we use large-scale MD simulations to investigate the mechanical response of a
simple glass-forming system under the effect of an external stress. At sufficiently low density,
a deep quench leads to a system with a gel-like bicontinuous structure that is fully arrested in
the limit where thermal fluctuations are negligible [1]. Here, as the applied shear stress
increases, the system response changes from creep deformation, with power-law dependence
on time, to macroscopic failure; for intermediate stress values reentrant solid-like behavior is
reported. While this scenario is stable with respect to the choice of temperature T and density
ρ, the creep exponent is not universal as its specific value depends on T, ρ and the applied
stress. In particular a deeper quench results in a change from power-law to logarithmic creep.
Further, steady flow is observed only for larger densities, approaching the dense regime, in
which the gas phase occupies disconnected bubbles inside the dense one. Heterogeneous flow
takes place in the form of a shear band localized in a small region close to the cavity. Our
approach, based on microscopic simulations, allow the study of creep dynamics and failure at
the atomic level, overcoming the limitations of the experiments on this subject. We show that
macroscopic creep is connected to particles inability to diffuse: the large part of the system is
virtually arrested whereas few mobile particles constitute sparse cluster located at the
interfaces between dense and gas phases. Finally, focusing on microscopy dynamics, we
investigate the possibility to predict the onset of macroscopic failure.
REFERENCES
1. Testard, V., Berthier, L., and Kob, W., J. Chem. Phys. 140, 164502 (2014).
POSTER P-7
Poster teory
Roskilde University Molecular Dynamics with GPUs
Heine Larsen
Glass and Time, Department of Science and Environment, Roskilde University, Denmark
RUMD is a general purpose, high-performance molecular dynamics (MD) simulation package
runningon graphical processing units (GPU’s). RUMD addresses the challenge of utilizing
the many-core nature of modern GPU hardware when simulating small to medium system
sizes (roughly from a few thousand up to hundred thousand particles). It has a performance
that is comparable to other GPU-MD codes at large system sizes and substantially better at
smaller sizes. RUMD is open-source and consists of a library written in C++ and the CUDA
extension to C, an easy-to-use Python interface, and a set of tools for set-up and post-
simulation data analysis. The paper describes RUMD’s main features, optimizations and
performance benchmarks.
REFERENCES
1. Bailey, N. P., Ingebrigtsen, T. S., Hansen, J. S., Veldhorst, A. A., Bøhling, L., Lemarchand, C. A.,
Olsen, A. E., Bacher, A. K., Larsen, H., Dyre, J. C., Schrøder, T. B., RUMD: A general purpose
molecular dynamics package optimized to utilize GPU hardware down to a few thousand particles,
arXiv, physics.comp-ph, 1506.05094 (2015).
P-8 POSTER
Theor-Simul
Effects of changing the molecular polarity on the structural
and dynamical properties of liquid silica
Elvira Pafong, Barbara Drossel, Michael Vogel
Institut für Festkörperphysik, Technische Universität Darmstadt
Silica is a network-forming liquid that shares many properties with water. Both liquids are
polar which leads to directional bonds as well as complex structural and dynamical properties.
In particular, liquid silica undergoes a transition from a strong to a fragile glass former, [1]
comparable to the transition from a high-density liquid (HDL) to a low-density liquid (LDL)
reported in water. Here, we investigate the effect of the molecular polarity on the structure
and dynamics of silica-like liquid models using molecular dynamics simulations in a
systematic manner. We modify polarity by changing the partial charges assigned to each
atom, thus changing the relative contribution of the van der Waals and the electrostatic
interaction. We evaluate structural properties such as tetrahedral order and dynamical
properties such as relaxation times and activation energies in dependence of the values of the
partial charges and of the temperature. We find that the ratio between high-temperature and
low-temperature activation energy increases linearly with charge, while no explicit correlation
can be obtained between activation energies and the glass transition temperature. It is also
shown that while the temperatures of the fragile-to-strong transition and of the density
maximum change with the charge, the structural properties at those temperatures are similar.
We finally study the relation between diffusivity and structural relaxation times in silica-like
liquids.
REFENCES
1. Geske, J., Drossel, B., and Vogel, M., Fragile-to-strong transition in liquid silica, AIP Advances 6,
035131:1-11 (2016)
POSTER P-9
Dyn-Hetero
Kinetics studies of mutarotation of L-sorbose in the
supercooled region in context of crossover temperature
K. Wolnica,a,b
M. Dulski,a,c
E. Kaminska,d M. Tarnacka,
a,b R. Wrzalik,
a,b K.
Kaminski a ,b
and M. Paluch a ,b
a Silesian Center for Education and Interdisciplinary Research, 75 Pulku Piechoty 1a, 41-500
Chorzow, Poland
b A. Chelkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007
Katowice, Poland
c Institute of Material Science, University of Silesia, 75 Pulku Piechoty 1a, 41-500 Chorzow,
Poland.
d Department of Pharmacognosy and Phytochemistry, Medical University of Silesia in
Katowice, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, ul.
Jagiellonska 4, 41-200 Sosnowiec, Poland
Intra- and intermolecular studies on the molten L-sorbose were carried out with the use of
Fourier Transform Infrared (FTIR), Raman and Broadband Dielectric (BD, BDS)
Spectroscopies to evaluate the impact of crossover temperature (Tc) on the progress of
mutarotation in this carbohydrate. Unexpectedly, a strong change in the pace of reaction as
well as its activation barrier (Ea) was noted. Such significant change in kinetics of
mutarotation of L-sorbose can’t be explained from the chemical point of view. Presented
results shall help in better understanding of the relationship between heterogeneous nature of
condensed matter and the progress of chemical reaction in the supercooled region.
P-10 POSTER
Colloids
Dense Microswimmer Systems in Model Porous Media
Jonathan Ónody , Thomas Voigtmann
Deutsches Zentrum für Luft- und Raumfahrt e.V., Linder Höhe, 51147 Köln
We investigate model microswimmers (active Brownian particles) evolving in a porous
medium making use of the mode-coupling theory (MCT) of the glass transition. The
microswimmers are modeled by hard disks in two dimensions undergoing both, translational
and rotational diffusion. In addition they posses a constant self-propulsion velocity in their
direction of orientation. The porous background is treated as an extension to the theory of V.
Krakoviack. Working in the Smoluchowski picture and applying the Mori-Zwanzig
projection-operator formalism, a integro-differential equation for the density correlator is
achieved. The mode-coupling approximated memory-kernel and first numerical results are
presented.
REFERENCES
1. Schilling, R., Scheidsteger, T., Mode coupling approach to the ideal glass transition of molecular
liquids: Linear molecules, Phys. Rev. E. 56, 2932 (1997).
2. Krakoviavk, V., Mode-coupling theory for the slow collective dynamics of fluids adsorbed in
disordered porous media, Phys. Rev. E. 75, 031503 (2007).
3. Götze, W., Complex Dynamics of Glass-Forming Liquids – A Mode-Coupling Theory
POSTER P-11
Colloids
Ordered Aggregation of Cationic Porphyrins on
Inorganic Polyphosphate Exterior
Olga Ryazanova1, Victor Zozulya
1, Igor Voloshin
1, Alexander Glamazda
1,
Mykola Ilchenko2, Igor Dubey
2, Victor Karachevtsev
1
1B. Verkin Institute for Low Temperature Physics and Engineering of NAS of Ukraine,
47 Nauki ave., 61103, Kharkiv, Ukraine
2Institute of Molecular Biology and Genetics of NAS of Ukraine,
150 Zabolotnogo str., 03143, Kyiv, Ukraine
Cationic meso-porphyrins are well-known macrocyclic compounds possessing by unique
photophysical properties and high photosensitizing ability, which can form ordered
aggregates on polyanionic scaffolds that makes them promising agents for applications in
nanomedicine and nanotechnology including design of new photonic materials and devices
etc. The polymers with alternating phosphate groups in the chain are widespread in the living
organisms and in the all biological systems. Inorganic polyphospate (PPS) represents a linear
chain of orthophosphate residues each carrying a monovalent negative charge, therefore it can
serve as polyanionic scaffold to assemble cationic macromolecules [1]. The rotational
flexibility of the P-O-P bonds allows the conformational adjustment of PPS chains to the π-π
stacks of cationic organic dyes. Comprehensive study on binding of tetra- and tricationic
meso-porphyrins, TMPyP4 and TMPyP3+
, to PPS was performed in aqueous solutions in a
wide range of molar phosphate-to-dye ratios using different spectroscopic techniques and
DFT calculation method. It was established that stoichiometric mixture of inorganic
polyphosphate with these porphyrins results in substantial transformation of absorption and
fluorescence spectra, quenching of porphyrin emission, substantial increase in the sample
viscosity and appearance of strong light scattering. It was assumed that formation of the stable
ordered porphyrin aggregates is occurred on the PPS exterior (H-type in the case of TMPyP4,
and mixture of J- and H-types in the case of TMPyP3+
) with their subsequent integration in
higher order aggregates where multiple polymer strands are interconnected by π-stacked
porphyrin molecules. The size of the aggregates estimated from light scattering data reaches
several hundred nanometers.
REFERENCES
1. Brown, M.R.W., Kornberg, A. Inorganic polyphosphate in the origin and survival of species. Proc.
Natl. Acad. Sci. USA 101, 16085-16087 (2004).
P-12 POSTER
Colloids
Transition from diffusive to subdiffusive motion in colloidal
liquids
M. J. Sánchez-Miranda
Instituto de Física, Universidad Autonoma de San Luis Potosí, Mexico.
manuelj(at)dec1.ifisica.uaslp.mx
In this work we report experimental and theoretical results for the motion of single colloidal
particles embedded in complex fluids with different interparticle interactions. The motion of
particles is found to follow a similar behavior for the different systems. In particular, the
transition from the short-time diffusive motion to the subdiffusive intermediate-time motion is
found to occur when the square root of its mean squared displacement is in the order of 1
tenth of the neighbors' interparticle distance, thus following a quantitative criterion similar to
Lindemann's criterion for melting.
POSTER P-13
Polym-Dyn
Dynamics and relaxation in new fluorinated side chain
polymers: an ESR investigation
Laura Andreozzi1, Giancarlo Galli
2, Fabio Zulli
1,, Diego Palazzuoli
1
1Department of Physics “ E. Fermi” , University of Pisa and IPCF-CNR, 56127 Pisa, Italy
2Department of Chemistry and Industrial Chemistry, University of Pisa, 56124 Pisa, Italy
Fluorinated azobenzene liquid crystalline polymers appear promising materials as optical data storage
substrates, especially in holographic recording, for their ability of suppressing surface relief (1). Their
applicative importance also arises from the excellent water repellency (2) and the possibility of
modulating wettability by the change in the dipole moment of the cis-trans photochromic species (3).
The comprehension of the mechanism by which the internal structure and molecular architecture of
these materials affect their microscopic relaxation phenomena will address an ever improved design
for technological applications and a fundamental understanding, enlightening the presence of
cooperative mechanisms or/and dynamic heterogeneity.
A new series of fluorinated homopolymers and random copolymers were investigated. They share the
same main chain, and differentiate from a previous series (4, 5) for the substitution of the −(𝐶𝐻2)4𝐶𝐻3
group with the −𝐶𝐹3 one in the terminal part of the azobenzene-containing side chain.
The study was carried out by electron spin resonance to investigate the dynamics and matrix
heterogeneity of the new series of copolymers, also in comparison with the previous non-fluorinated
series. The structural relaxation of the polymers was also investigated by rheological measurements.
Different molecular architectures result in modulation of the relaxation properties at nanoscale level.
Dynamics and matrix heterogeneity is discussed, highlighting how the different molecular architecture
affects different dynamic responses and matrix heterogeneity over different length and time scales.
Information on cooperativity of the dynamics is also provided.
REFERENCES
1. You, F., Paik, M. Y., Häckel, M., Kador, L., Kropp, D., Schmidt, H. W., and Ober, C. K., Adv. Funct.
Mater. 16: 1577, (2006).
2. Xiong, S. D., Guo, X. L., Li, L., Wu, S.l., Chu, P.K., and Xu, Z.S. J. Fluorine Chem., 131: 417, (2010).
3. Ichimura, K., Oh, S. K., and Nakagawa, M., Science. 288 (5471): 1624, (2000) ; Abbott, S., Ralston, J.,
Reynold, G., and Hayes, R., Langmuir. 15: 8923, (1999); Siewierski, L. M., Brittain, W. J., Petrash, S., and
Foster, M.D., Langmuir. 12: 5838, (1996).
4. Andreozzi, L., Faetti, M., Giordano, M., Palazzuoli, D., and Galli, G., Macromolecules. 34: 7325, (2001).
5. Andreozzi, L., Galli, G., Giordano, M., Martinelli, E., and Zulli, F., Macromolecules. 48: 6541, (2015)
P-14 POSTER
Polym-Dyn
Field-Cycling NMR techniques down to 3 Hz for
investigations of polymer dynamics
Benjamin Kresse1, Manuel Becher
1, Alexei F. Privalov
1, Marius Hofmann
2,
Ernst A. Rössler3, Michael Vogel
1, Franz Fujara
1
1Institut für Festkörperphysik, TU Darmstadt, Hochschulstr. 6, 64289 Darmstadt, Germany
2Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA
3Experimentalphysik II, Universität Bayreuth, 95440 Bayreuth, Germany
Field-Cycling (FC) NMR traces spectral densities of molecular or ionic motions by measuring
the spin-lattice relaxation dispersion in a broad range of Larmor frequencies. By rapidly
switching the magnetic field from a high polarization field down to a small evolution field
and back to a high detection field the relaxation process can be tracked in ultra low magnetic
fields.
The first part of this contribution deals with technical aspects of our home built FC
relaxometer, demonstrating that experiments at ultra low Larmor frequencies down to about 3
Hz are possible. Several low-field experiments are presented: Larmor precession about tilted
evolution fields, simultaneous measurements of the Larmor frequency and the spin-lattice
relaxation, as well as the irradiation of oscillating transversal magnetic field pulses as a novel
method for field calibration in FC NMR at ultra low fields [1].
The second part focuses on applications of FC NMR. One example for the potential of low-
field approaches are 1H relaxation dispersion of water at low frequencies, which provide
access to slow proton exchange process. Another example are FC measurements of time-
dependent mean square displacements of polymer melts with different molecular masses. By
a combination of FC and field-gradient (FG) NMR ten orders of magnitude in time are
covered and all four power-law regimes of the tube-reptation model for polymer dynamics are
identified with exponents close to the predicted ones [2].
REFERENCES
1. Kresse, B., Becher, M., Privalov, A. F., Hofmann, M., Rössler, E. A., Vogel, M., Fujara, F., 1H NMR at
Larmor frequencies down to 3 Hz by means of Field-Cycling techniques, J. Magn. Reson. 277, 79–85
(2017).
2. Kresse, B., Hofmann, M., Privalov, A. F., Fatkullin, N., Fujara, F., Rössler, E. A., All Polymer Diffusion
Regimes Covered by Combining Field-Cycling and Field-Gradient 1H NMR, Macromolecules. 48, 4491–
4502 (2015).
POSTER P-15
Polym-Nanocom
Structure and dielectric/electrical characteristics of
segregated polymer composites with carbon fillers
Oleksii Maruzhenko1,2
, Yevgen Mamunya1, Gisèle Boiteux
2,
Anatoli Serghei2, Sébastien Pruvost
3
1 Institute of Macromolecular Chemistry, National Academy of Sciences of Ukraine;
48 Kharkivske chaussee, 02160 Kyiv, Ukraine
2 Université de Lyon, Université Lyon 1, Ingénierie des Matériaux Polymères;
UMR CNRS 5223, 69 622 Villeurbanne Cedex, France
3 Université de Lyon, INSA Lyon, Ingénierie des Matériaux Polymères;
UMR CNRS 5223, 69 621 Villeurbanne Cedex, France
Conductive polymer composites are usually two-phase systems, namely polymer matrix
(thermoplastic or thermoset) that provides mechanical properties, and conductive filler
(carbon, metallic, ceramic) which impart needed dielectric/electrical characteristics. However
random distribution of conductive particles within polymer matrix requires high filler content
to achieve conductivity and, consequently, that leads to high percolation threshold and
inferior mechanical properties. Use of segregated polymer composites is good way to avoid
such problems and decrease filler content. In segregated polymer composites conductive filler
creates an ordered framework within polymer matrix. The local concentration of filler φloc in
the wall of framework is much higher than mean filler concentration φ related to the whole
volume of polymer matrix, φloc> φ. Owing to this the percolation threshold, defining the
insulator/conductor transition, that influences on dielectric/electrical characteristics, is much
lower than for the random distribution of filler in conventional polymer composites.
We used broadband dielectric spectroscopy (Novocontrol Alpha-A) in the frequency range
10-1
-107 Hz to investigate segregated systems based on ultra-high-molecular-weight
polyethylene filled with carbon fillers such as microsized - anthracite (A) and nanosized -
graphene (Gr), thermally expanded graphite (TEG), graphene nanoplates (GNP), and hybrid
filler – graphene/anthracite (Gr-A) with ratio 1/3. For comparison the systems with random
distribution of filler based on polypropylene and epoxy resin with anthracite was used. It was
found good correlation between electrical characteristics measured on AC and DC. The big
difference between composites with micro- and nanofillers was found.
Also thermal conductivity of segregated systems was investigated and thermal behavior was
compared with electrical properties of polymer composites.
P-16 POSTER
Polym-Nanocom
Effect of accelerators on the dynamics of rubber blends
Lucía Ortegaa,
*, Mathias Meyerb, Clemens Sill
b, Nihat Ali Isitman
b, Stephan
Westermannb, Silvina Cerveny
a,c and Gustavo A. Schwartz
a,c
aDonostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
bGlobal Materials Science, Goodyear Innovation Center Luxembourg, Avenue Gordon Smith,
L-7750 Colmar-Berg, Luxembourg
cCentro de Física de Materiales (CFM, CSIC/UPV) – Materials Physics Center (MPC), Paseo
Manuel de Lardizabal 5, 20018 San Sebastián, Spain
Accelerators are fundamental ingredients in the sulfur vulcanization of rubber compounds
increasing the cure rate and yield thereby allowing the cure process to proceed at lower
temperatures and with higher efficiency. However, the presence of accelerators in the rubber
compound can affect the segmental dynamics or even be related with slower relaxation
processes. In this work we present a broadband dielectric study on the effect of accelerators
on the dynamics of vulcanized styrene-butadiene rubber compounds with different accelerator
structures and loading levels.
The dynamics of all the samples show a main peak (besides the beta relaxation) as a sum of
two relaxation processes. While the fastest relaxation corresponds to the segmental polymer
dynamics, the origin of the low frequency contribution was attributed to a process arising
from a component that is not covalently bonded to the polymer chain and not restricting the
segmental dynamics.
POSTER P-17
Polym-Nanocom
ARUZ - Large-scale FPGA-based Analyzer of Real
Complex Systems
K. Halagan1, J. Jung
1, R. Kielbik
2, P. Polanowski
1, J. Ulanski
1,
A. Napieralski2
1Department of Molecular Physics, Lodz University of Technology,
Zeromskiego 116, 90-924 Lodz, Poland 2Department of Microelectronics and Computer Science, Lodz University of Technology,
Wolczanska 221/223, 90-924 Lodz, Poland
The Dynamic Lattice Liquid model [1], proposed by Tadeusz Pakula, is designed to simulate
dynamics in complex liquid systems, like polymer solutions, melts, multi-phase systems, etc.
[2,3]. Algorithm based on this model was an inspiration to design large-scale, massively
parallel device with possibility of reconfiguration. This device – called ARUZ (Analyzer of
Real Complex Systems) [4,5] – was constructed in BioNanoPark in Lodz (Poland) using
reconfigurable components – FPGAs (Field Programmable Gate Array) instead of common
processors. It is a scalable, fully parallel data processing system dedicated for simulations
based on emulation of interactions among huge amount of relatively simple elements. These
elements can represent atoms, molecules or groups of atoms. ARUZ is composed of almost
26 000 FPGAs (the biggest FPGA-based machine in the world to our knowledge)
interconnected in three-dimensional network by 75 000 cables. It can represent the system
composed of several million of elements in ms time scale (more than 3x108 algorithm steps
per day). The simulation can take into account various phenomena like molecular diffusive
motion, covalent bond breaking/creating, chemical reactions of different orders, non-covalent
interactions, external fields and different boundary conditions. ARUZ can be used in research
of complexity in chemistry of macromolecules and variety of physical phenomenon.
REFERENCES
1. PAKULA, T., TEICHMANN J., Collective dynamics in simple supercooled and polymer liquids, J. Mol.
Liq. 86, 109-121 (2000).
2. KOZANECKI, M., HALAGAN, K., SARAMAK, J., MATYJASZEWSKI, K., Diffusive properties of
solvent molecules in neighborhood of polymer chain as seen by Monte-Carlo simulations, Soft Matter 12,
5493-5654 (2016).
3. POLANOWSKI, P., SIKORSKI, A., Comparison of different models of motion in a crowded environment:
a Monte Carlo study, Soft Matter 13, 1693-1701 (2017).
4. KIELBIK, R., HALAGAN, K., ZATORSKI, W., JUNG, J., ULANSKI, J., NAPIERALSKI, A.,
RUDNICKI, K., AMROZIK, P., JABLONSKI, G., STOZEK, D., POLANOWSKI, P., MUDZA, Z.,
KUPIS, J., ARUZ - Large-scale, Massively Parallel FPGA-based Analyzer of Real Complex Systems,
Comput. Phys. Commun., in review, (2017).
5. EU patent applications by JUNG, J., at al.: EP3079066, EP3079071, EP3079072, EP3079073.
P-18 POSTER
Polym-Nanocom
Segmental Dynamics of Polystyrene-grafted Silica
Nanocomposites with Tunable Spatial Distribution
Yu Lin, Guozhang Wu
Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and
Engineering, East China University of Science and Technology, Shanghai 200237, China
A continuing challenge of polymer nanocomposites (PNCs) is to establish the relationship
between the interfacial layer chain packing and dynamics. In this study, we report the spatial
distribution and dynamics of polystyrene-grafted silica (SiO2-PS) particle filled PS and
poly(methyl methacrylate) (PMMA) nanocomposites. The results reveal that tunable specific
spatial distribution of grafted nanoparticles can be obtained through the control of grafted
chain polymerization degree (N) and grafting density (σ). The bulklike α-relaxation dynamics
of PS matrix is unaffected by the silica NP loadings, while it is shown to slow down the α-
relaxation dynamics in PMMA nanocomposites. More interestingly, we probe the enhanced
mobility of interfacial layer (α′-relaxation) in PNCs filled with grafted NPs, which is further
corroborated by the accelerated Maxwell-Wagner-Sillars (MWS) polarization process.
Moreover, it is unexpected that the α′-relaxation time increases with increasing temperature in
the vicinity of glass transition temperature (Tg) of polymer matrix. Such an anomalous
temperature dependence behavior can be attributed to the influence exerted by the slower α-
relaxation dynamics. Considering the phenomena presented above, we propose the three-layer
model to explain the observed behavior of grafted silica NP filled nanocomposites. These
findings provide new insight into the mechanisms responsible for mechanical reinforcement
and therefore guide the design of PNCs with tunable macroscopic properties.
REFERENCES
1. Kumar, S.K., Jouault, N., Benicewicz, B., Neely, T., Nanocomposites with polymer grafted nanoparticles,
Macromolecules. 46, 3199-3214 (2013).
2. Bansal, A., Yang, H.C., Li, C. Z., Cho, K. W., Benicewicz, B. C., Kumar, S.K., Schadler, L.S., Quantitative
equivalence between polymer nanocomposites and thin polymer films, Nature Materials. 4, 693-698 (2005).
POSTER P-19
Polym-Nanocom
Effect of processing oils on the dynamics of rubber blends
Lucía Ortegaa,
*, Mathias Meyerb, Clemens Sill
b, Nihat Ali Isitman
b, Stephan
Westermannb, Silvina Cerveny
a,c and Gustavo A. Schwartz
a,c
aDonostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
bGlobal Materials Science, Goodyear Innovation Center Luxembourg, Avenue Gordon Smith,
L-7750 Colmar-Berg, Luxembourg
cCentro de Física de Materiales (CFM, CSIC/UPV) – Materials Physics Center (MPC), Paseo
Manuel de Lardizabal 5, 20018 San Sebastián, Spain
Processing oils are used in a wide variety of industries as raw material components as well as
processability improvers. When used in rubber compounds, a good compatibility of the
process oil with the polymer matrix is required to obtain the desired final properties. The
presence of oil can affect the dynamics of the polymers in different ways. For instance, small
molecule diluents like treated distillate aromatic extract oil (TDAE) can reduce the severity of
constraints on the local motion and, thereby, reducing the degree of intermolecular
cooperativity. In this work, we have analysed the oil content effect on the dynamical
behaviour of neat styrene-butadiene rubber, butadiene rubber and their blends by means of
differential scanning calorimetry and broadband dielectric spectroscopy. In the case of
butadiene rubber, we have observed that the segmental relaxation shifts to lower frequencies
in the presence of the diluents, showing a glass transition temperature (Tg) increase effect,
while for the styrene-butadiene rubber we observed the contrary response. The oil
incorporation in rubber compounds shows a Tg decrease or increase effect, depending on the
relative oil and polymer blend glass transition temperatures.
P-20 POSTER
Conf-TF
Decoupling between molecular mobility and glass transition
in polymer nanospheres by fast scanning calorimetry
Natalia G. Perez-de-Eulate, Valerio di Lisio, Daniele Cangialosi
Centro de Física de Materiales, Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
Departamento de Física de Materiales, University of the Basque Country (UPV/EHU), San
Sebastian 20018, Spain
Dipartimento di Chimica, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Roma,
Italy
Centro de Física de Materiales, Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
In the present contribution we investigate glass dynamics of polystyrene (PS) nanospheres
with diameter ranging from 200-600 nm, obtained by means of nanoprecipitation.1 To do so
we have employed fast scanning calorimetry (FSC), which allows exploring cooling/heating
rates as large as several thousands Kelvin per second. The cooling rate dependent limiting
fictive temperature (Tf), determined by the Moynihan method,2 which defines the
thermodynamic state achieved by the glass after a certain cooling protocol, exhibits clear
decrease with the nanospheres diameter. Similar results, agreeing with those of the Tf, were
found for the liquid to glass transition temperature (Tg), obtained by a step response method.3,4
Conversely, the so-called “dynamic” Tg, obtained by the step response method and in the
same experiment as the Tg by Fourier transforming heat flow and cooling rate signals, 3,4
revealed essentially bulk-like dynamics. These results provide compelling arguments that the
thermal Tg – related to the way the glass former vitrifies – and the dynamic Tg – providing
information on the intrinsic molecular mobility – are decoupled for glasses subjected to
geometrical confinement.5,6
REFERENCES
1. Zhang, C.; Pansare, V. J.; Prud’homme, R. K.; Priestley, R. D. Flash Nanoprecipitation of Polystyrene
Nanoparticles. Soft Matter 8, 86–93 (2012).
2. Moynihan, C. T.; Easteal, A. J.; DeBolt, M. A.; Tucker, J. Dependence of the Fictive Temperature of Glass on
Cooling Rate. J. Am. Ceram. Soc. 59, 12–16 (1976).
3. Merzlyakov, M.; Schick, C. Step Response Analysis in DSC — a Fast Way to Generate Heat Capacity Spectra.
Thermochim. Acta 380, 5–12 (2001).
4. Shoifet, E.; Schulz, G.; Schick, C. Temperature Modulated Differential Scanning Calorimetry – Extension to High
and Low Frequencies. Thermochimica Acta 603, 227–236 (2015).
5. Cangialosi, D.; Alegría, A.; Colmenero, J. Effect of Nanostructure on the Thermal Glass Transition and Physical
Aging in Polymer Materials. Prog. Polym. Sci. 54–55, 128–147 (2016).
6. Priestley, R. D.; Cangialosi, D.; Napolitano, S. On the Equivalence between the Thermodynamic and Dynamic
Measurements of the Glass Transition in Confined Polymers. J. Non-Cryst. Solids 407, 288–295 (2015).
POSTER P-21
Conf-TF
Tuning confinement effects on thin films of poly(4-
tertbutylstyrene) with one free surface
Natalia G. Perez-de-Eulate, Michele Sferrazza, Daniele Cangialosi, Simone
Napolitano
Centro de Física de Materiales, Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
Departamento de Física de Materiales, University of the Basque Country (UPV/EHU), San
Sebastian 20018, Spain
Département de Physique, Faculté des Sciences, Université Libre de Bruxelles (ULB),
Boulevard du Triomphe, Bruxelles 1050, Belgium
Centro de Física de Materiales (CSIC-UPV/EHU), Paseo Manuel de Lardizábal 5, San
Sebastián 20018, Spain
Laboratory of Polymer and Soft Matter Dynamics, Faculté des Sciences, Université Libre de
Bruxelles (ULB), Boulevard du Triomphe, Bâtiment NO, Bruxelles 1050, Belgium
In the present contribution we investigate poly(4-tert-butyl styrene) films ranging from 25 to
265 nm, by means of spectroscopic ellipsometry technique. It is shown that when a 25-nm-
thin film of poly(4-tert-butyl styrene) cooled down at constant rate it vitrifies 50 K lower than
in bulk.1 This record sets the largest depression in thermal glass transition temperature (Tg)
ever observed upon confinement at the nanoscale level. Same as for other supported polymer
layers, this reduction in Tg has been attributed to the presence of a free surface, the ensemble
of molecules at the interface with air remaining in the liquid state also at temperatures well
below bulk Tg.2 In this work, we verify that such tremendous shifts can be erased upon
prolonged annealing in the liquid state, hinting at a metastable nature of confinement effects.3
We demonstrate that the recovery of bulk behavior and the manifestation of the free surface
are enslaved to the kinetics of irreversible adsorption of chains on the supporting substrate.
REFERENCES
1 Ellison, C. J.; Mundra, M. K.; Torkelson, J. M. Impacts of Polystyrene Molecular
Weight and Modification to the Repeat Unit Structure on the Glass
Transition−Nanoconfinement Effect and the Cooperativity Length Scale. Macromolecules 38,
1767–1778 (2005).
2 Napolitano, S.; Glynos, E.; Tito, N. B. Glass Transition of Polymers in Bulk, Confined
Geometries, and near Interfaces. Rep. Prog. Phys. 80, 036602 (2017).
3 Napolitano, S.; Wubbenhorst, M. The Lifetime of the Deviations from Bulk Behaviour
in Polymers Confined at the Nanoscale. Nat. Commun. 2, 260 (2011).
P-22 POSTER
Conf-TF
Ion and Molecule Transport in Surface Functionalized
Nanopores - a NMR Study
Sarah Schneider and Michael Vogel
TU Darmstadt Solid State Physics
Hochschulstraße 6, 64289 Darmstadt, Germany
We analyze ion and molecule transport in peptide-functionalized nanopores. This endeavor
aims to assist a development of a new generation of nanosensors, which combine biological
and synthetic nanopores. While being highly selective and sensitive, biological ion channels
lack the robustness for technological applications. Contrarily silica pores are well proven in
industrial and clinical environments, but possess inferior capabilities, e.g. no selectivity. A
hybrid system would combine the favorable properties of both fields.
To optimize such pores, it is of strong interest to understand the influence of various
confinements on the ion and molecule transport inside. Such confined dynamics depend on
the pore geometry and the guest-host interactions determined by the properties of the inner
surfaces. We vary these parameters systematically, in particular by peptide functionalization
of silica surfaces, and study their effects on the dynamics by NMR. We combine various
NMR techniques which provide access to local dynamics, with NMR approaches in field
gradients to measure self-diffusion coefficients. These methods proved well suited to analyze
the dynamics of pure water [1,2]. Here, we apply them to aqueous salt solutions in bulk and
nanopore confinement. The experimental setups include ¹H and ²H NMR to investigate water
dynamics as well as ⁷Li and ²³Na NMR to analyze the diffusion of various ionic species.
We find a strong slowdown of both local dynamics and translational diffusion in confinement.
Temperature dependent T1 relaxation measurements to analyze local dynamics reveal that the
T1 minimum for the confined system appears at higher temperature compared to the bulk
solution, indicating the slowdown. In translational diffusion this is seen by smaller diffusion
coefficients in MCM-41 easily by an order of magnitude, e.g. 1e-11 m2/s in bulk and 1e-12
m2/s in confinement at 210K. However, the extent of the slowdown and the relation between
short- and long-range dynamics substantially depends on the confinement properties.
Reference
1. Sattig, M., and Vogel, M., J. Phys. Chem. Lett. 5, 174 (2013).
2. Sattig, M., et al., Phys. Chem. Chem. Phys. 16, 19229 (2014).
POSTER P-23
Conf-TF
Thermal behavior of liquid crystal substance
N-(2-hydroxy-4-methoxybenzylidene)-4’-n-butylaniline
(OHMBBA）
Kousuke Shido1, Takehisa Yoshimi
1, and Hiroki Fujimori
1
1Graduate School of Integrated Basic Sciences, Nihon University, 3-25-40 Sakurajosui,
Setagaya-ku, Tokyo 156-8550, Japan
Liquid crystal is a substance having both crystal and liquid properties. It is considered that
intermolecular interaction is greatly involved in the formation of liquid crystal phase, and
restricting it is considered to cause a change in physical properties in the formation of a liquid
crystal phase. N-(2-hydroxy-4-methoxybenzylidene)-4’-n-butylaniline (OHMBBA) is an
analogue of N-(4-methoxybenzylidene)-4-butylaniline (MBBA) which is a typical liquid
crystal substance. The molecular size in the minor axis direction of OHMBBA is larger than
MBBA by the amount of the hydroxyl group, and in the OHMBBA there is an intramolecular
hydrogen bond between -OH and -N. The transition temperatures of OHMBBA are 317 K for
the crystalline phase to the nematic one and 337.5 K for the nematic one to the isotoropic one
[1].
In this study, differential scanning calorimetry (DSC) measurements of OHMBBA confined
within mesoporous silica were performed to discuss the thermal properties of the molecules in
the mesoscopic region. As a result of the measurements, it was found that the transition
temperatures of OHMBBA were decreased with decreasing the diameter of pores, and the
glass transition temperatures depend the cooling rate of the sample.
Reference
1. Sorai, M., S. Seki, Short Communications, , 2887 (1971).
P-24 POSTER
Conf-TF
Local dynamics in confinement: The use of naphthalene
derivatives in triplet state solvation dynamics
Peter Weigl¹, Philipp Ritzert¹, Thomas Walther² and Thomas Blochowicz¹
¹Institute for condensed matter physics,
²Institute of applied physics,
Technische Universität Darmstadt, 64289 Darmstadt, Germany
For a better understanding of confinement effects such as surface, density and finite-size
effects, it is essential to gain local insight into the dynamics of confined systems. By means of
the triplet state solvation dynamics (TSD) technique, it is possible to gain information about
the local relaxation dynamics. In TSD a dye is dissolved at low concentration in the sample
and is excited into a metastable long-lived triplet state by a UV laser pulse. Due to the
relaxation of the surrounding solvent molecules, the emission spectrum of the dye becomes
red shifted. The time resolved Stokes-shift, which can be measured in a range from
milliseconds up to seconds, can be used to evaluate the local relaxation of the solvation shell¹.
For this local information it is important to determine the position of the dye by using
different combinations of polar and nonpolar dyes with hydrophobic and hydrophilic surfaces²
or by chemically connecting the dye onto the surface. For the latter approach, it is necessary
to look for suitable alternative chemicals since commonly used dyes cannot be attached easily
to a confining surface. So far, naphthalene derivatives seem to be promising candidates,
which can be excited by our laser system³. Our aim is to connect such a dye onto a confining
surface and use the great advantage of our measurement technique to investigate the local
relaxation dynamics in different confined systems. These can be systems with hard
confinement such as in nanopores as well as intrinsically confined systems, where the dye is
connected to a macromolecule. With this starting point it is possible to answer many
questions on the topic of confined systems from a local point of view.
Reference
1. Richert, R., Triplet state solvation dynamics: Basics and applications, J. Chem. Phys. 113, 8404-8429
(2000).
2. Wen, W., Richert, R., Viscous nonpolar liquids in confinement studied by mechanical solvation, J. Chem.
Phys., 131, 084710 (2009).
3. Talluto, V., Blochowicz, T., Walther, T., A nanosecond regenerative Ti:Sapphire amplifier for the
simultaneous generation of 940 nm and of 320 nm pulses, Appl. Phys. B, 122, 132 (2016).
POSTER P-25
Proc-SR-Boson
Effect of chemical structure on the dielectric response of
van der Waals liquids
Agnieszka Jedrzejowska,1,2
K. L. Ngai,3 Marian Paluch
1,2
1Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland
2Silesian Center for Education and Interdisciplinary Research, 75 Pulku Piechoty 1, 41-500
Chorzow, Poland
3CNR-IPCF, Dipartimento di Fisica, Universita di Pisa, Largo B. Pontecorvo 3, I-56127, Pisa,
Italy
The analysis of dielectric relaxation data of van der Waals glass-forming liquids revealed a
strong correlation between the width of the frequency dispersion of the α-relaxation and the
dielectric strength Δε; originating from the dipole-dipole interaction contribution to the
intermolecular potential.1 The aim of this study is to critically test the correlation proposed by
Paluch et al. by means of dielectric spectroscopy measurements.
One example of material confirming the correlation is low-molecular propylene carbonate
(PC) with a large dipole moment (μ=4.94 D) coming from the cyclopenta-1,3-dioxolan-2-on
ring. Therefore, in our study we have chosen family of van der Waals liquids with properly
modified chemical structure of PC. Examined liquids can be divided into two categories:
(i) derivatives with delicate modification of chemical structure of PC (and similar values of
dipole moment); and (ii) glass-formers with more evident modification of chemical structure
of PC (exhibiting different values of dipole moment than propylene carbonate). Our dielectric
spectroscopy measurements were performed in a wide range of temperatures under ambient
and elevated pressure.
In this poster, we will demonstrate that even slight changes in chemical structure of studied
glass-formers can affect significant influence on such parameters as: glass transition
temperature, fragility, distribution of relaxation times, and etc. Finally, our experimental
results constitute a new evidence for validity of correlation between dielectric strength and the
frequency dispersion of the dielectric response of the structural relaxation process.
REFERENCES
1. Paluch, M., Knapik, J., Wojnarowska, Z., Grzybowski, A., Ngai, K. L., Universal Behavior of
Dielectric Responses of Glass Formers : Role of Dipole-Dipole Interactions, Physical Review
Letters. 116, 025702 (2016).
P-26 POSTER
Proc-SE-Boson
Vitrifying by pressure: fundamental importance of the JG
relaxation
Sofia Valentia, Simone Capaccioli
a,b, M. Shahin Thayyil
c, K. L. Ngai
b
aDipartimento di Fisica, Università di Pisa, Largo Bruno Pontecorvo 3, I-56127, Pisa, Italy
bCNR-IPCF, Largo Bruno Pontecorvo 3, I-56127, Pisa, Italy
cDepartment of Physics, University of Calicut, Kerala, India
Secondary relaxations, faster than the cooperative -process responsible for glass transition, have been observed
in supercooled and glassy state. These modes are local and non-cooperative and two types of relaxation can be
distinguished: intramolecular and intermolecular. While the first one depends on internal degrees of freedom of
the relaxing molecule, the second, called also the Johari-Goldstein (JG) relaxation [1], involves motions of the
whole molecule and is universally found in the amorphous state [2]. On the Energy Landscape (EL) framework
[3], these motions correspond to jumps between local minima inside the much larger minimum (called
megabasin) representing the state of the glass. The single molecules, hence, move through the intermolecular
potential generated by their first neighbors, so the density of the system plays an important role on the local
dynamics: when pressure is applied, the volume of the glass changes, changing its EL and the distribution of
relaxation times of JG relaxation. Consequently the the study of the molecular dynamics under pressure is a
critical test to reveal the nature of secondary relaxations.
This study uses Broadband Dielectric Spectroscopy (BDS) to investigate the dynamics of both binary mixtures
and pure compounds over a wide range of temperature and pressure. For binary mixtures, polar rigid molecules,
i.e. benzonitrile and tripropyl phosphate (TPP), were dissolved at low concentration in apolar solvents
(oligostyrenes).
A strong interdependence between the structural and the JG relaxation has been found when changing pressure,
suggesting an intermolecular nature of JG relaxation [3]. Not only the value of the JG relaxation time, but also its
shape remains constant for different combinations of T-P values, keeping constant the -relaxation time.
Activation volumes and energies changes with pressure and temperature accordingly. Our results can be
completely rationalized by the Coupling Model predictions [2, 4]. In the glassy state the averaged response of the
independently relaxing dipoles gives a distribution of relaxation times, from which a distribution in the energy
barriers involved in the process can be inferred [5].
REFERENCES
1. Johari, G. P., Goldstein, M., Viscous liquids and the glass transition. II: secondary relaxations in glasses of
rigid molecules, The Journal of Chemical Physics. 53, 2372-2388 (1970).
2. Ngai, K. L., Relaxation and Diffusion in Complex Systems, Springer: New York (2011).
3. Debenedetti, P.G, Stillinger, F.H., Supercooled liquids and the glass transition, Nature. 410, 259-267 (2001).
4. Kessairi, K., Capaccioli, S., Prevosto, D., Lucchesi, M., Sharifi, S., Rolla, P. A., Interdependence of
Primary and Johari−Goldstein Secondary Relaxations in Glass-Forming Systems, The Journal of Physical
Chemistry B. 112, 4470-4473 (2008).
5. Gainaru, C., Böhmer, R., Kahlau, R., Rössler, E., Energy landscape in molecular glasses probed by high-
resolution dielectric experiments, Physical Review B. 82, 104205 (2010).
POSTER P-27
Proc-SR-Boson
Thermodynamic features and sub-Tg enthalpy relaxation in
a melt-quenched metal-organic framework glass - ZIF-62
Zhou, Chao1, Bennett, T. D.
2, Yue, Y. Z.
1
1Department of Chemistry and Bioscience, Aalborg University, Frederik Bajers Vej 7H, DK-
9220 Aalborg, Denmark
2Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles
Babbage Road, CB3 0FS Cambridge, UK
Metal-organic frameworks (MOFs) have been extensively investigated in recent decades
because of their multi-functionalities for applications such as gas absorption, catalysis and
sensing. A subset of MOFs, called zeolitic imidazolate frameworks (ZIFs), has been found to
be of particular interest due to their potential to play a role like zeolites. However, the melt-
quenched ZIF glasses are of recent origin. It has been discovered that certain types of ZIFs
can melt prior to decomposition, and hence, can be vitrified upon quenching.[1-3] Study of
this new family of glasses gives new angles to understand fundamental glass problems such as
crystal melting, glass formation, glass transition, and glass relaxation. In the present work, we
study enthalpy relaxation and thermodynamic properties in ZIF-62 (Zn(Im)1.75(bIm)0.25) glass.
Its enthalpy relaxation time described by the Kohlrausch model demonstrates a broad
distribution with the stretching exponent β of 0.4 to 0.8. We have found that β increases with
increasing annealing temperature. These relaxation behaviors indicate a high degree of the
structural heterogeneity at medium-range scale in ZIF-62 glass. Moreover, the temperature
dependence of the Gibbs free energy of ZIF-62 in the range of temperature from Tg to Tm is
found to be weaker than that of metallic glasses. Owing to such small thermodynamic driving
force ZIF-62 is an extremely stable glass former against crystallization.
REFERENCES
1. Bennett, T. D., Tan, J. C., Yue, Y. Z., Baxter, E., Ducati, C., Terrill, N. J., Yeung, H. H. M., Zhou, Z.,
Chen, W., Henke, S., Cheetham, A. K., Greaves, G. N., Hybrid glasses from strong and fragile metal-
organic framework liquids, Nature Communications. 6, 8079 (2015).
2. Bennett, T. D., Yue, Y. Z., Li., P., Qiao., A., Tao., H. Z., Greaves, G. N., Richard., T., Lampronti, G. I.,
Redfren, S. A. T., Blanc, F., Farha, O. K., Hupp, J. T., Cheetham, A. K., Keen, D. A., Melt-Quenched
Glasses of Metal–Organic Frameworks, Journal of the American Chemical Society. 138, 3484-3492 (2016).
3. Tao, H. Z., Bennett, T. D., Yue, Y. Z., Melt-Quenched Hybrid Glasses from Metal–Organic Frameworks,
Advanced Materials. 1601705 (2017).
P-28 POSTER
H-Pressure
A green and efficient synthesis of fully substituted 1,2,3-
triazoles under high pressure
Iwona Grudzka-Flaka, b
, Andrzej Dzieniab, c
, Mariola Bartoszekc, Paulina
Maksyma, b
, Magdalena Tarnackaa, b
, Kamil Kamińskia, b
, Marian Palucha, b
aInstitute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland
bSilesian Center for Education and Interdisciplinary Research, University of Silesia, 75 Pulku
Piechoty 1A, 41-500 Chorzów, Poland
cInstitute of Chemistry, University of Silesia, Szkolna 9, 40-007 Katowice, Poland
Triazoles are well known biologically active compounds with general formula C2H3N3
formed in five membered ring of three nitrogen and two carbon atoms. Their unique
properties, especially biological activity, derive from stiffness and stability in vivo conditions,
as also ability of creating hydrogen bonds and specific dipole moment of main core –
aromatic triazole ring. Such chemical and physical properties results with wide application
potential ranging from biological and medical science (as anticancer drugs, HIV protease
inhibitiors, antifungal agents, antituberculosis, antimalarial, antiviral and antibacterial drugs)
to material science (as for example dyes, photostabilizers, energetic materials, lubricants) as
well as in modern organic synthesis as versatile building building blocks, ligands for catalysis
and directing groups for transition-metal-catalyzed C-H activation [1-4].
The most popular route for the synthesis of fully substituted 1,2,3-triazoles is Huisgen
cycloadditon of azides and alkynes catalyzed by ruthenium complexes. However, this method
is subjected to certain substrates restrictions. By replacing the catalyst with high pressure it is
possible to eliminate this problem.
We present a simple, highly efficient, catalytic and solvent free, enviromental friendly method
for synthesis of trisubstituted 1,2,3-triazoles under high pressure. The main advantage of
presented protocol is the fact that there are no side reactions and only the desired product is
generated which means that purification and any kind of potential applications (especially
medical ones) are greatly simplified.
REFERENCES
1. Rodriguez-Rodriguez M., Gras E., Pericas M.A., Gomez M., Chem. Eur. J. 21, 18706-18710 (2015).
2. Thomas J., John J., Parekh N., Dehaen W., Angew. Chem. Int. Ed. 53, 10155-10159 (2014).
3. Durga Bhaskar Yamajala K., Patil M., Banerjee S., JOC 80, 3003-3011 (2015).
4. Yap A. H., Weinreb S. M., Tetrahedron Letters 47, 3035-3038 (2006).
POSTER P-29
H-Pressure
High pressure water-initiated Ring Opening Polymerization
in the synthesis of well-defined -hydroxy--(carboxylic
acid) polycaprolactones
A. Dzienia1,2
, P. Maksym1 ,3
, M. Tarnacka1,3
, A. Zięba4, K. Kaminski
1, 3,
M. Paluch1,3
1 Silesian Center of Education and Interdisciplinary Research, University of Silesia, ul. 75 Pulku Piechoty 1A,
41-500 Chorzow, Poland
2 Institute of Chemistry, University of Silesia, ul. Szkolna 9, 40-003 Katowice, Poland
3 Institute of Physics, University of Silesia, ul. Uniwersytecka 4, 40-007 Katowice, Poland
4 Department of Organic Chemistry, School of Pharmacy with the Division of Laboratory Medicine in
Sosnowiec, Medical University of Silesia in Katowice, Jagiellonska 4, 41-200 Sosnowiec, Poland
Development of green ε-caprolactone (CL) polymerization method is the most
important challenge of modern polymer chemistry. Herein, we propose a novel way to
produce polyesters of well-defined chemical structure, narrow molecular weight distributions
by using combination of high pressure, temperature and water. We found two competitive
phenomena: polymerization and crystallization occurring at high compression. Once the latter
process is avoided, the control over the reaction is reached. By varying the thermodynamic
condition and concentration of water molecule, polymers of moderate molecular weights
(Mn=1.6-19.0 kg/mol) and dispersities (Ð≈1.07-1.50) could be produced. Additional NMR
experiments supported by further MALDI TOF analysis enable us to determine telechelic
hydroxyl and carboxylic/acidic moieties as terminal groups of produced PCLs. Finally, the
latter measurements also indicated that increase in dispersity above 1.3 is strongly related to
the competitive reactions leading to production cyclic polyesters. Presented results open
alternative routes to produce PCL of enhanced biocompatibility and biodegradability using
the greenest method reported to date.
P-30 POSTER
IonLiq-Polym
Synthesis of tailored imidazolium-based polyelectrolytes
with enhanced conductivity by RAFT
Paulina Maksym1,2
, Magdalena Tarnacka1,2
, Andrzej Dzienia2,3
, Kamil
Kaminski1,2*
, Marian Paluch1,2
1 Institute of Physics, University of Silesia, ul. Uniwersytecka 4, 40-007 Katowice, Poland
2 Silesian Center of Education and Interdisciplinary Research, University of Silesia, ul. 75
Pulku Piechoty 1A, 41-500 Chorzow, Poland
We demonstrate here the controlled synthesis by Reversible Addition Fragmentation Chain
Transfer (RAFT) of two specially designed imidazolium-based poly(ionic liquid)s (PILs),
such as the poly(1-methyl-3-vinylimidazolium bis(trifluoromethanesulfonyl)imide)
P[MVIM][NTf2] and poly(1-ethyl-3-vinylimidazolium bis(trifluoromethanesulfonyl)imide)
P[EVIM][NTf2]. Depending on the varied ratios of monomer to chain transfer agent (CTA)
([monomer]/[CTA]=100/1; 400/1; 1000/1) we obtained P[MVIM][NTf2] and P[EVIM][NTf2]
homopolymers with the number-average molecular weights (Mn) in broad range Mn=2.5-340.0
kDa and Mn=2.1-450.0 kDa, respectively. Additionally, a systematic exploration of their
physicochemical properties including glass transition temperatures (Tg) and conductivity has
been conducted. Interestingly, it was found that the resulting PILs exhibited an unexpected
evolution of Tg vs Mn in the limit of low molecular weight. We observed an increase in the
glass transition temperature by 50-70 degrees, in contrast to the literature data, where only
small variation of Tg with Mn is reported [1]. Surprisingly, the obtained PILs (characterized by
coulomb interactions and enhanced conductivity, σdc ~ 10-9 S/cm at Tg,) revealed behavior
comparable to those observed in case of van der Waals polymer, as polystyrene or
polyisobutylene, despite the significant differences in the interactions.
REFERENCES
1. Fan, F., Wang, W., Holt, A. P., Feng, H., Uhrig, D., Lu, X., Hong, T., Wang, J., Kang, N-G., Mays, J.,
Sokolov, A. P., Effect of Molecular Weight on the Ion Transport Mechanism in Polymerized Ionic Liquids,
Macromolecules. 49, 4557–4570 (2016).
2. Wojnarowska, Z., Knapik, J., Díaz, M., Ortiz, A., Ortiz, I., Paluch, M. Conductivity Mechanism in
Polymerized Imidazolium-Based Protic Ionic Liquid [HSO3–
BVIm][OTf]: Dielectric Relaxation Studies,
Macromolecules. 47, 4056–4065 (2014).
POSTER P-31
IonLiq-Polym
Molecular dynamics of supercooled ionic liquids studied by
light scattering and dielectric spectroscopy
Florian Pabst
TU Darmstadt, Germany
We investigated molecular dynamics of supercooled room temperature ionic liquids (RTILs)
right above their glass transition by means of dynamic light scattering and broadband
dielectric spectroscopy from nanoseconds up to ~10^5 seconds. We show that a direct
combination of the raw data of these two techniques allows us to identify the reorientation of
ions in the dielectric data, giving direct experimental evidence to a very recently proposed
model of Gainaru et. al,[1] stating that the conductivity process in ionic liquids take place
through a reorientational step of ions escaping their cage formed by surrounding counterions.
Within this approach we can also understand the apparent decoupling of time constants from
dielectrics and light scattering, often found in ionic liquids,[2] in a very natural way.
Furthermore, as a consequence of knowing the reorientational part of the dielectric spectrum,
we are able to show that two more processes contribute to these spectra, which are due to
polarization effects. The relative position of these three contributions among themselves vary
among the systems and may overshadow each other, thus complicating the data analysis and
favor misinterpretations.
REFERENCES
1. Gainaru, C., Stacy, E. W., Bocharova, V., Gobet, M., Holt, A. P., Saito, T., Greenbaum, S., and Sokolov,
A. P., “Mechanism of conductivity relaxation in liquid and polymeric electrolytes:Direct link between
conductivity and diffusivity,” The Journal of Physical Chemistry B, vol. 120, no. 42, pp. 11074–11083,
(2016)
2. Griffin, P. J., Agapov, A. L., and Sokolov, A. P., “Translation rotation decoupling and nonexponentiality in
room temperature ionic liquids,” Phys. Rev. E, vol. 86, p. 021508, (2012)
P-32 POSTER
IonLiq-Polym
Molecular Dynamics Simulations of Ionic Liquid Films on
Silica Surface
Tamisra Pal and Michael Vogel
Institut für Festkörperphysik
Technische Universität Darmstadt , 64289 Darmstadt , Germany
Room temperature ionic liquid (IL) films on solid substrates have been recognized for their
significant interfacial properties in electrochemical and electronic devices. To ascertain the
role of hydrophobicity of the anions, we chose ILs composed of 1-butyl-3-
methylimidazolium cations and hexafluorophosphate ([Bmim][PF6]) or tetrafluoroborate
([Bmim][BF4]) anions. The dynamical and structural properties of these ILs confined between
amorphous silica slabs are investigated by all-atom molecular dynamics simulation studies at
300 K. Density profiles of the ionic species across the slit are calculated. The more
hydrophilic [BF4]- ions tend to stay closer to the slab wall than [PF6]-, whereas the [Bmim]+
ions always reside in the second layer resulting in a bi-layered arrangement near the wall. A
preferred orientation has been observed for the cations with their methyl groups pointing
towards the slab surface and butyl tails projected inwards. The middle of the slit displays
more of a bulk behavior in terms of structure and dynamics. Spatially–resolved analyses of
the mean square displacement and incoherent intermediate scattering function reveal very
sluggish and heterogeneous dynamics of all ionic species in the vicinity of the silica surface.
Specifically, structural relaxation times increase by two orders of magnitude, which needs to
be considered when designing applications.
POSTER P-33
Met-Glas
Structural relaxation of metallic glass Cu50Zr50 and its
effect on mechanical properties
Chunguang Tang1, Hailong Peng
2, Yu Chen
1, and Michael Ferry
1
1School of Materials Science and Engineering, University of New South Wales, NSW 2052,
Australia;
2Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft-und Raumfahrt (DLR),
51170 Köln, Germany
Bulk metallic glasses (BMGs) are among the most promising metallic materials, partly
because of their ultra-high strength due to their glassy structure generated by rapid quenching
from the liquid phase. However, most monolithic BMGs usually suffer catastrophic failure
without any appreciable macroscopic plastic deformation. This is due to the localization of
plastic strain in a few shear bands (SBs) that propagate in an autocatalytic manner, leaving
regions outside the bands to be only elastically deformed. Suppression of major shear band
formation and propagation is crucial for improving the mechanical properties of BMGs.
In this work (ref 1) through molecular dynamics simulations we study the structural relaxation
of metallic glass Cu50Zr50 as a function of quenching rates and its effect on shear band
behaviour. It is found that at higher quenching rates the samples have more free volume and a
lower local fivefold symmetry, and consequently active local shearing or plastic deformation
occurs at relatively low stress. Energetically, this process dissipates the applied elastic strain
energy and hence prevents the formation of major shear bands, leading to larger plasticity.
Also, it was found that the atomic diffusion in the shear band for the slowly quenched
samples is substantially quicker than in the necking area for the rapidly quenched samples.
REFERENCES
1. Tang, C., Peng, H., Chen, Y., Ferry, M., Formation and dilatation of shear bands in a Cu-Zr
metallic glass: A free volume perspective, Journal of Applied Physics. 120, 235101 (2016).
P-34 POSTER
Met-Glas
Relaxation processes in nanocrystalline
Mn1.1Fe0.9P0.5As0.48Ge0.02 magnetocaloric compound
Patryk Wlodarczyk, Lukasz Hawelek, Aleksandra Kolano-Burian
Institute of Non-Ferrous Metals, ul. Sowinskiego 5, 44-100 Gliwice, Poland
The main aim of the work was to study molecular dynamics in the nanocrystalline
Mn1.1Fe0.9P0.5As0.48Ge0.02 compound. The compound was prepared by mechanical alloying in
the planetary mill from pure elements (Fe, Mn, P, Ge) and binary compounds (FeAs2).
Thereafter powder was compressed, sintered and annealed in the vacuum furnace. The purity
of the compound was checked by the Rigaku MiniFlex diffractometer. Impurity i.e.
manganese oxide MnO doesn’t exceed 5 wt% of the sample. In order to prepare
nanocrystalline sample, intermetallic compound was milled in the planetary mill. The powder
was sieved and thereafter the smallest fraction (<10 mm) was analyzed by SEM in order to
check its average grain size. Molecular dynamics of this compound was studied by means of
dynamomechanical analysis at various frequencies (0.1 – 10 Hz) and in a function of
temperature (223K – 373K). Finally the metallic powder was mixed with cellulose (from 1 to
5 wt%) in order to check its impact on the absorption of electromagnetic (EM) radiation in the
radio and microwave frequency range (up to 3 GHz). The DC conductivity, and EM
absorption coefficients of mixtures were measured by means of broadband dielectric
spectroscopy.
POSTER P-35
Water-HB
Thermostimulated transitions in thin cryovacuum deposited
films of the two-component CH4+H2O mixture
Drobyshev A., Aldiyarov A., Korshikov E., Sokolov D., Tokmoldin N.,
Shinbayeva A.
Al-Farabi Kazakh National University, Almaty, Kazakhstan
Stable homogenous states of aqueous hydrocarbon solutions may only be observed at high
temperatures and pressures extending beyond the critical region of the components. Upon
transition of the two-component system into the region of super-cooled (metastable) states,
with low values of thermodynamic variables, homogeneity may be preserved together with
internal stability. This work is the result of structure-phase equilibria studies of the two-
component water-methane system in the region of metastable states of co-existing phases. In
such systems the region of metastable states is thermodynamically analogous to structure
forming conditions in single-component systems [1].
Vapor mixtures of water and methane with various ratios deposited under strongly metastable
non-equilibrium conditions onto a cooled substrate in vacuum were the objects of the study.
Obtained low-temperature thin films were studied using the vibration spectroscopy technique
in the temperature range of 16-180K. During thermal annealing of the samples, characteristic
vibrational C-H bands of methane were monitored alongside desorption pressure in relation to
the annealing temperature.
In the process of sample annealing we observed changes in the monitored thermodynamic
parameters acting as indicators of the structure-phase state of the low-temperature thin films.
The results of the study reveal that upon co-deposition of methane and water a homogeneous
system is formed with various inferred states of the methane molecule in the crystalline water
framework: quasi-free, pore-captured and clathrate-like.
REFERENCES
1. Drobyshev, A., Aldiyarov, A., Sokolov, D., ИК спектрометрические исследования тонких
пленок криовакуумных конденсатов метана и смеси метан–вода, Low Temperature Physics.
43, 3, 505-512 (2017).
P-36 POSTER
Water-HB
Dynamic behavior of Lyxose-water mixtures during
isothermal crystallization
Zhen Chen
School of Science, Anhui Agricultural University, Hefei, China
The dynamic behavior of mixtures of water and other hydrogen bonded liquids have some
common features, including a slow alpha-process due to the cooperative dynamics of the
mixture and a fast beta-like process that is believed to be associated to the dynamics of water
molecules[1,2]
. The latter dynamic process as well as how it is influenced by the state of water
molecules in the mixture, are still not well understood. In this study, we use dielectric
spectroscopy to monitor the variation of the dielectric behavior of lyxose-water mixtures with
different water content during their isothermal crystallization process, through which we hope
to reveal how the crystallization of water influences the dynamic behavior of the mixtures and
to have a better understanding on the featured alpha and beta processes.
REFERENCES
1. Cerveny, S., et al., Water dynamics in n-propylene glycol aqueous solutions, The Journal of Chemical
Physics. 124, 194501 (2006).
2. Sjostrom, J., et al., Dielectric secondary relaxation of water in aqueous binary glass-formers, Physical
Chemistry Chemical Physics. 12, 10452-10456 (2010).
POSTER P-37
Water-HB
Slow rheological mode in supercooled glycerol and glycerol -
water mixtures
Mikkel Hartmann Jensen1,2
, Tina Hecksher1, Catalin Gainaru
3, Christiane
Alba-Simionesco2, and Kristine Niss
1
1) Glass & Time, Dept. of Science and Environment, Roskilde University, Denmark
2) Laboratoire Léon Brillouin, UMR 12 CEA-CNRS, Saclay, France
3) Fakultät für Physik, Technische Universität Dortmund, Germany
Linear hydrogen-bonded structures are believed to be responsible for the short chain polymer-
like slow rheological mode recently reported for supercooled mono-alcohols1. Here we show
a similar spectral anomaly for a poly-alcohol, the prototypical glass-former glycerol. This
slow mode curiously weakens when water is added and disappears for a molar concentration
of glycerol between 0.5 and 0.6. Dielectric spectra of glycerol-water mixtures2,3
in the same
concentration range show a quite different behavior: neat glycerol displays a single narrow
relaxation loss peak and with adding water the primary peak broadens.
We propose that the observed rheological mode is caused by the hydrogen bonded network
and discuss the origin of the weakening of the mode in the glycerol-water mixtures. The
dielectric invisibility of that mode may be due to cancellation of dipoles in the network
structure. The qualitative difference in results between shear and dielectric spectroscopy
stress that in combination they form a powerful tool for investigations into supercooled liquid
dynamics.
REFERENCES
1. Gainaru, C., Figuli, R., Hecksher, T., Jakobsen, B., Dyre, J. C., Wilhelm, M., and Böhmer, R., Shear-
Modulus Investigations of Monohydroxy Alcohols: Evidence for a Short-Chain-Polymer Rheological
Response, Phys. Rev. Lett. 112, 098301 (2014).
2. Popov, I., Gutina, A. G., Sokolov, A. P., and Feldman, Y., The puzzling first-order phase transition in
water–glycerol mixtures, Physical Chemistry Chemical Physics. 17, 18063-18071 (2015).
3. Puzenko, A., Hayashi, Y., Ryabov, Y. E., Balin, I., Feldman, Y., Kaatze, U., and Behrends, R., Relaxation
Dynamics in Glycerol-Water Mixtures: I. Glycerol-Rich Mixtures, J. Phys. Chem. B, 109, 6031-6035 (2005)
P-38 POSTER
Water-HB
Slow Dynamics Of Supercooled Aqueous Solutions of
Trehalose
Antonio Iorioa, Gaia Camisasca
a,*, Paola Gallo
a
aDipartimento di Matematica e Fisica, Università “Roma Tre”, Via della Vasca Navale 84,
00146 Roma, Italy
*Present Address: Department of Physics, Stockholm University, 10691 Stockholm, Sweden
Water is one of the most prominent complex liquid that shows anomalies when cooled. It is
thought that such a behaviour stems from the fundamental role played by the hydrogen bonds
between water molecules [1]. From a dynamical point of view the most prominent
microscopic theory that is able to partially explain water glassy dynamics upon supercooling
is the Mode Coupling Theory (MCT). MCT was initially developed in the framework of
simple liquids but its predictions are remarkably good also in explaining the slow dynamic of
supercooled water [2]. Of particular interest is the dynamical behaviour of aqueous solutions
of different disaccharides. These solutions are very common in nature and their interesting
properties may help to understand the anomalies of supercooled water, e.g. how the disruption
of water hydrogen bonds due to the presence of other molecules may affect the dynamic of
supercooled water. Moreover aqueous solutions of this kind are relevant in many
technological applications, such as cryopreservation of organic molecules [3, 4]. In this
context, trehalose has been proven to be especially effective, when added to a solutions of
water, to slow down the dynamics of water.
In this work we study the dynamics of aqueous solutions of trehalose at different
concentrations using molecular dynamics simulations. Analysis of dynamic quantities, such as
density-density autocorrelation functions and diffusion coefficients, is carried out in the MCT
framework. This allows us to extract important quantities that are able to describe the
behaviour of the system (e.g. relaxation times τ and critical temperature TC).
REFERENCES
1. Gallo, P., et al, Water: A Tale of Two Liquids, Chemical Reviews. 116, 7463-7500 (2016).
2. Gallo, P., Sciortino, F., Tartaglia, P., Chen, S. H., Slow Dynamics of Water Molecules in Supercooled
States, Phys. Rev. Lett. 76, 2730-2733 (1996); Sciortino, F., Gallo, P., Tartaglia, P., Chen, S. H.,
Supercooled water and kinetic glass transition, Phys. Rev. E. 54, 6331-6342 (1996).
3. Magno, A., Gallo, P., Understanding the Mechanisms of Bioprotection: A Comparative Study of Aqueous
Solutions of Trehalose and Maltose upon Supercooling, J. Phys. Chem. Lett. 2, 977-982 (2011).
4. Corradini, D., Strekalova, E. G., Stanley, H. E., Gallo, P., Microscopic mechanism of protein
cryopreservation in an aqueous solution with trehalose, Scientific Reports. 3, 1218 (2013).
POSTER P-39
Water-HB
Ultrasonic Sound Velocity Measurements for Liquid
Water-Glycerol Mixtures
K. Nukumizu, Y. Kajihara and M. Inui
Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8521, Japan
In liquid water-(monohydric)alcohol mixtures, there are known many thermodynamic
anomalies1. The origin of the anomalies is widely believed its special mixing state and the
thermodynamic excess functions have been discussed1. On the other hand, there was also an
opinion that the anomalies of the mixture are attributed to the anomalies of water itself2. In
either case, there is no direct experimental evidence and no conclusion has been reached.
In order to conclude this unsolved problem of water-alcohol mixtures, we study the system by
the new experimental concept which we proposed ourselves3. The essence of the method is to
deduce the relaxation intensity from the ratio of two sound velocities; one by a low-frequency
method like ultrasonic wave and the other by a high-frequency one like inelastic x-ray
scattering. In water-ethanol, water-methanol4 and water-glycerol
5 mixtures, the composition
dependence of this relaxation intensity at room temperature shows peak at pure water and it
gradually decrease with increasing alcohol concentration. Thus we conclude that the origin of
thermodynamic anomalies of water-alcohol mixtures are attributed to the large relaxation
intensity of water itself, which is universal not only for water-monohydric alcohol mixtures
but also for water-trihydric alcohol mixture.
In the present study, we have carried out ultrasonic sound velocity measurements for liquid
water-glycerol mixtures in the wide temperature (150 to 320 K) and whole concentration
region. The interesting point of the system is that glycerol-rich sample is hardly frozen below
the melting point and we can obtain both the low-frequency limit and the high-frequency limit
of the sound velocities by one ultrasonic measurement with changing the temperature, which
was already reported for pure glycerol6. Detail of the results and the universal view for water-
alcohol mixtures will be presented.
REFERENCES
1. Franks, F., et al, Q. Rev. 20 , 1 (1966)
2. D’Arrigo, G., and Paparelli, A., J. Chem. Phys., 88, 405 (1988)
3. Kajihara, Y., et al, J. Phys.: Condens. Matter 20, 494244 (2008)
4. Shibata, N., Kajihara, Y., et al, in preparation
5. Kajihara, Y., et al, EPJ web conf., accepted
6. Yan, Y.-X., et al, J. Chem. Phys. 88, 6477 (1988)
P-40 POSTER
Water-HB
Water Dynamics in Mesoporous Silica: Insights from a
Combined NMR and BDS Approach
Edda Klotz, Matthias Sattig, Christina Lederle, Max Schäfer
and Michael Vogel
Institut für Feskörperphysik, TU Darmstadt, Germany
Hochschulstraße 6
64289 Darmstadt
The investigation of the dynamics of water in confinement is relevant for various fields of
interest, from biological applications to geological ones. It is well established that confined
water undergoes a dynamic crossover upon supercooling. However, the origin of this
phenomenon is controversially discussed [1]. For example, it was conjectured that the
dynamic crossover is a consequence of a solidification of one fraction of the confined water.
([2], [3], [4]) To further study this issue, we focus on water im MCM-41 silica nanopores and
use por diameters for which well defined partial freezing occurs. Calorimetric studies are
performed to characterize this freezing behavior. Moreover, nuclear magnetic resonance
(NMR) and broadband dielectric spectroscopy (BDS) are applied to ascertain the dynamics of
the non-freezing water fraction across the freezing transition. The dielectric spectra exhibit
several processes that are sensitive to an appearance of a solid water fraction, as evident from
their temperature dependence. 2H NMR allows us to show that one of the processes can be
identified with the rotational motion of water, exhibiting a kink in the temperature depenence
at the freezing-transition. Moreover, 1H static field gradient NMR yields self-diffusion
coefficients of water, which can be linked to freezing-affected polarization processes in BDS.
Thus, these combined studies clearly show a dynamic crossover due to formation of a solid
water fraction.
REFERENCES
1. Cerveny, S., Mallamace, F., Swenson, J., Vogel, M., and Xu, L., Confined Water as Model of Supercooled
Water, Chemical Reviews. 116(13), 7608–7625 (2016)
2. Sattig, M., and Vogel, M., Dynamic crossovers and stepwise Solidification of Confined Water: A 2H NMR
study, The Journal of Phys. Chem. Letters. 5(1), 174-178 (2014)
3. Sattig, M., Reutter, S., Fujara, F., Werner, M., Buntkowsky, G., and Vogel, M., NMR studies on the
temperature-dependent dynamics of confined water, Phys. Chem. Chem. Phys. 16, 19229–19240 (2014)
4. Rosenstihl, M., Kämpf, K., Sattig, M., and Vogel, M., Dynamics of interfacial water, Journal of Non-
Crystalline Solids. 407, 449-458 (2015)
POSTER P-41
Water-HB
Is the compression modifying the properties of diols?
Sławomir Kołodziej ,a,c
Sebastian Pawlus,a,c
Michał Wikarek ,a,c
Stella Hensel-
Bielówkaa,b,c
aInstitute of Physics, University of Silesia, Katowice, Poland
bInstitute of Chemistry, University of Silesia, Katowice, Poland
cSilesian Center for Education and Interdisciplinary Research, Chorzów, Poland
Does the number of hydroxyl groups influence the molecular dynamics of the alcohols? If we
compare the dielectric results from investigations of monohydroxy alcohols and diols, then
the answer is YES. The existence of an additional OH-group, in the case of diols, results in
the disappearance of the Debye process in the dielectric spectra. However, next question arise,
if not only the number, but also the position of the OH-groups on the molecules backbone can
change the relaxation properties of these alcohols? Additionally, if any differences of the
properties of diols with seemingly similar molecular architecture remain undetectable during
investigations performed at ambient pressure, can we expected some differences at high
pressure conditions?
To answer these questions – at least partially – data collected for a series of diols, examined
by the use of dielectric spectroscopy at ambient and elevated pressure, are presented. The
results explain not only how the position of the hydroxyl groups at the alkyl backbone
influence the molecular dynamics of the studied liquids, but also the meaning of the length of
this chain for the relaxation properties of the diols under investigation.
P-42 POSTER
Water-HB
Dielectric Relaxation of Water and Ice in Partially
Crystallized Poly (ethylene glycol)-Water Mixtures
Masahiko Miyara, Ikeru Takashima, Kaito Sasaki, Rio Kita,
Naoki Shinyashiki, and Shin Yagihara
Graduate School of Science and Technology, Tokai University,
4-1-1 Kitakaname, Hiratsuka-shi, Kanagawa 259-1292, Japan
The dielectric relaxation process of water was investigated for partially crystallized
polymer−water mixtures1. On the other hand, the unique water structure around poly
(ethylene glycol) (PEG) in the PEG–water mixtures was studied by differential scanning
calorimetry2. According to the investigation, the two times melting of ice and eutectic of
water–PEG were observed. In this study, we observed relaxation process caused by molecular
motion of water and ice in the PEG−water mixtures to clarify the relationship between ice and
eutectic by using dielectric spectroscopy.
PEG and water mixtures with 10–50 wt% PEG were prepared. Dielectric measurements of the
10–50 wt% PEG–water mixtures were performed in the frequency range of 10 mHz to 50
GHz at temperatures between −150 and 25 °C. We used three instruments to cover the
frequency range: an Alpha−A analyzer (Novocontrol), an impedance material analyzer
(Hewlett Packard, E4294A) and a network analyzer (Agilent Technologies, N5230C).
According to the experimental results, the relaxation processes of water and ice were
observed. Water in the PEG–water mixtures can be classified into three types: ‘water included
in ice’, ‘water included in the eutectic’ and ‘water remaining in the liquid state’. The dynamic
properties of these types of water were clarified. The values of relaxation time of water in the
PEG–water mixtures are smaller than those in the other polymer–water mixtures below 0 °C.
The local fluctuation of the PEG chain, which has a smaller relaxation time than those of
other polymers in water mixtures, and the characteristic hydration structure around the PEG
chain prevent the formation of ice crystals even for water with a small relaxation time3. We
will present in detail the relationship between ice and eutectic.
REFERENCES
1. Shinyashiki, N., Shimomura, M., Ushiyama, T., Miyagawa, T., Yagihara, S., J. Phys. Chem. B. 111, 10079-
10087 (2007).
2. Huang, L., Nishinari, K., J. Polym. Sci. B Polym. Phys. 39, 496-506 (2001).
3. Miyara, M., Takashima, I., Sasaki, K., Kita, R., Shinyashiki, N., Yagihara, S., Polymer Journal. 49, 511-518
(2017).
POSTER P-43
Water-HB
The Frequency Dependence of the Ionic Conductivity in
Aqueous Ammonium Nitrate Solutions
Iwona Płowaś-Korus, Jolanta Świergiel, Jan Jadżyn
Institute of Molecular Physics, Polish Academy of Sciences, M. Smoluchowskiego 17,
60-179 Poznan, Poland
There are two main microscopic phenomena that lead to the dispersion of conductivity of
electrolytes. The first one occurs when blocking electrodes in the measuring cell are used [1–
3]. Then, in a low frequency region, the double layers are formed near the electrodes and with
decreasing frequency the conductivity decreases from its static value to zero, when the system
is totally blocked. The second phenomenon is related to the inertia of ions [4]. In the electric
field of high frequencies, ions can no longer follow rapid changes of the stimulus what leads
to decrease of the amplitude of oscillations of ions. Consequently, with increasing frequency
of the stimulus the inertial effect reveals as a gradual decreasing of the electrical conductivity
from the static value to zero.
These two ionic relaxation processes were recorded for the electrolyte solutions of water +
NH4NO3 [5]. The low frequency process exhibits a large distribution of relaxation times and
can be described with the empirical Cole-Cole equation while the high frequency process is
exactly of the Debye-type. It was found that when the conductivity of solution are increasing
(due to an increase of the electrolyte concentration or the temperature), the two relaxation
processes behave oppositely: the relaxation of double layers proceeds faster while the
relaxation due to the ions inertia proceeds slower.
REFERENCES
1. Singh, M.B., Kant, R., Theory for anomalous electric double layer dynamics in ionic liquids, J. Phys.
Chem. C. 118, 8766-8774 (2014).
2. Singh, M.B., Kant, R., Theory for anomalous dynamics of electric double layer at heterogeneous and rough
electrodes, J. Phys. Chem. C. 118, 5122-5133 (2014).
3. Wang, H., Pilon, L. Accurate simulations of electric double layer capacitance of ultramicroelectrodes,
J. Phys. Chem. C. 115, 16711-16719 (2011).
4. Chandra, A., Bagchi, B., Beyond the classical transport laws of electrochemistry: new microscopic approach
to ionic conductance and viscosity, J Phys. Chem. B. 104, 9067-9080 (2000).
5. Płowaś, I., Świergiel, J., Jadżyn, J., Frequency dependence of the ionic conductivity in water + ammonium
nitrate electrolyte solutions, Electrochim. Acta. 178, 511-516 (2015).
P-44 POSTER
Water-HB
Ice Structures inside Single Wall Carbon Nanotubes
P. Pugliese, M. M. Conde, M. Rovere and P. Gallo
Dipartimento di Matematica e Fisica, Università Roma Tre,
Via della Vasca Navale 84, 00146 Roma, Italy.
The study of confined water is an issue of general interest as it allows us not only to
investigate the general properties of water but it also has applicative purposes. Int this
framework the well characterized and ordered structure of the carbon nanotubes makes them a
perfect framework to investigate water confined in hydrophobic pores. There are several
experimental evidences that water can fill the space inside a single walled carbon nanotube
(SWCNT) at ambient condition [1] and it is also proven both experimentally [2] and by
simulation [3] that water inside the SWCNT cristallizes in a wide range of temperatures.
In particular it was recently experimentally discovered that water freezes already at ambient
conditions inside the nanotube [4]. We perform in this study molecular dynamics simulations
using for the water molecule a very realistic potential the TIP4P/Ice. This model was designed
to study the solid phases of water and gives also the best overall ices phase diagram and the
best predictions for the densities of several ice forms. In the present work we study in detail
the liquid solid transition temperatures and the kind of ordered structures that form by varying
the diameter of the SWCNT [5].
REFERENCES
1. Hummer, G., Rasaiah, J. C., & Noworyta, J. P, Water conduction through the hydrophobic channel of a
carbon nanotube, Nature. 414, 188-190 (2001)
2. Ghosh, S., Ramanathan, K.V., Sood, A. K.,Water at nanoscale confined in single-walled carbon nanotubes
studied by NMR, EPL (Europhysics Letters). 65, 678 (2004).
3. Koga, K, Gao, G.T., Tanaka, H., Zeng, X. C., Formation of ordered ice nanotubes inside carbon nanotubes,
Nature. 412, 802-805 (2001).
4. Agrawal, K. V., Shimizu, S., Drahushuk, L. W., Kilcoyne, D., and Strano, M. S., Observation of extreme
phase transition temperatures of water confined inside isolated carbon nanotubes, Nature Nanotechnology.
12, 267–273 (2017).
5. Pugliese, P., Conde, M. M., Rovere, M., and Gallo, P., in preparation (2017).
POSTER P-45
Water-HB
Glass Transition of Water and Polymer in Poly (vinyl
methyl ether)-Water Mixtures by Broadband Dielectric
Spectroscopy
Masanobu Takatsuka1, Kaito Sasaki
2, Naoki Shinyashiki
3,
Rio Kita2-3
, Shin Yagihara3
Graduate School of Science and Technology1, Micro/Nano Technology Center
2 and
Department of Physics, School of Science3 Tokai University, 4-1-1 Kitakaname, Hiratsuka,
Kanagawa 259-1292, Japan
The dynamics of molecules from liquid to glass state in a wide temperature range in water
mixtures with molecular liquids; ethylene glycol, ethylene glycol oligomers, glycerol, and
saccharides have been investigated by broadband dielectric spectroscopy (BDS). In these
investigations, the relaxation process, we call ν-process, originated from local motion of water
and the α-process, originated from the cooperative motion of hydrated solute were observed1. On
the other hand, polymer-water mixtures have also been investigated by BDS and only the
relaxation process of water was observed2-3. Although, the local segmental motion of polymer,
i.e., the α process was observed by neutron scattering, BDS measurement cannot detected it,
except for poly (vinyl pyrrolidone)-water mixtures4. In this study, BDS measurements of poly
(vinyl methyl ether)(PVME) and its water mixtures with 75, 80, and 90 wt. % of PVME were
performed in a frequency range from 10 mHz to 3 GHz to study the dynamics of water and
polymer and its relationships. Two relaxation processes were observed simultaneously in PVME-
water mixtures in extremely wide temperature range from liquid to glass state. The relaxation
process at higher frequency side originates from water and that observed at lower frequency side
originates from the local segmental motion of PVME. We will present in detail the relationship
between the relaxation processes of water and PVME.
REFERENCES
1. Shinyashiki, N., Sudo, S., Yagihara, S., Spanoudaki, A., Kyritsis, A., Pissis, P., Relaxation Processes of
Water in the Liquid to Glassy States of Water Mixtures Studied by Broadband Dielectric Spectroscopy, J.
Phys.: Condens. Matter. 19, 205113 (12pp) (2007).
2. Cerveny, S., Alegría, Á., Colmenero, J., Broadband dielectric investigation on poly (vinyl pyrrolidone) and
its water mixtures, J. Chem. Phys. 128, 044901-1-7 (2008)
3. Capponi, S., Arbe, A., Cerveny, Busselez, R., S., Frick, B., Embs, J. P., Colmenero, J., Quasielastic
neutron scattering study of hydrogen motions in an aqueous poly(vinyl methyl ether) solution, J. Chem.
Phys. 134, 204906 (2011).
4. Sasaki, K., Matsui, Y., Miyara, M., Kita, R., Shinyashiki, N., Yagihara, S., Glass Transition and Dynamics
of the Polymer and Water in the Poly(vinyl pyrrolidone)-Water Mixtures Studied by Dielectric Relaxation
Spectroscopy, J. Phys. Chem. B. 120, 6882-6889(2016)
P-46 POSTER
Alc-HB
Dielectric spectroscopy and rheology of monohydroxy
alcohols and mixtures with brominated solvents
S. Peter Bierwirth , Catalin Gainaru, Roland Böhmer
Technische Universität Dortmund, 44221 Dortmund, Germany
For a long time the Debye process of monohydroxy alcohols was only studied using dielectric
spectroscopy. Recently, it was discovered that this process is also accessible using mechanical
spectroscopy, e.g., near room temperature [1] or near the glass transition temperature of these
hydrogen bonded liquids [2]. Mixtures of isomeric octanols and other long-chain
monohydroxy alcohols with ethyl-hexylbromine and related solvents can reveal a complex
relaxation dynamics displaying surprising effects, see for instance Ref. 3. It will be
demonstrated that the combination of dielectric spectroscopy and rheology is useful to
disentangle the effects of Debye-like, primary, and secondary relaxations in such binary glass
formers can yield valuable insights regarding their transient suprastructure formation. The
potential of non-linear external perturbations for the study of monohydroxy alcohols will also
be considered.
Work supported by the Deutsche Forschungsgemeinschaft under Grant No. BO1301/14-1.
REFERENCES
1. R. Behrends, U. Kaatze, Hydrogen bonding and chain conformational isomerization of alcohols probed by
ultrasonic absorption and shear impedance spectrometry, J. Phys. Chem. A 105, 5829 (2001).
2. C. Gainaru, R. Figuli, T. Hecksher, B. Jakobsen, J. C. Dyre, M. Wilhelm, R. Böhmer, Shear-modulus
investigations of monohydroxy alcohols: evidence for a short-chain-polymer rheological response, Phys.
Rev. Lett. 112, 098301 (2014).
3. S. P. Bierwirth, P. Münzner, T. Knapp, C. Gainaru, R. Böhmer, Communication: Nonadditive dielectric
susceptibility spectra of associating liquids, J. Chem. Phys. 146, 101101 (2017).
POSTER P-47
Alc-HB
Debye and non-Debye Dipole Process in Shear Mechanical
and Dielectric Spectra of Glass molecular glass formers 2-
ethyl-1-hexanol and 2-butanol
G. Govindaraj
Department of Physics, School of Physical, Chemical and Applied Sciences, Pondicherry
University, Puducherry 605 014, India
Dielectric and mechanical relaxation process in glasses are a subject of interest, as they are deeply
connected different units of a molecule with their structure and dynamics. Based on our recent concept of
molecular level non-Debye relaxation processes (G. Govindaraj, AIP Conference Proceedings, 1731,
070025 (1)-(3) (2016); G. Govindaraj, arXiv:1608.05304, (2016)), expressions are obtained for dielectric
function as:
𝜖𝐺𝐺∗ (𝜔) = ∑ ([𝜖𝑑
∗ (𝜔)](𝝁−)𝑑
𝑛𝑚=1 + [𝜖𝑑
∗ (𝜔)](𝝁+)𝑑)𝑚 + 𝜎(0)/(𝑖𝜔𝜖0),
where
[𝜖𝑑∗ (𝜔)](𝝁−)𝑑
= 𝜖∞ + ∆𝜖/(1 + 𝑖𝛼𝑑(𝜔𝜏𝑑)𝛼𝑑) ; [𝜖𝑑∗ (𝜔)](𝝁+)𝑑
= ∆𝜖/(1 + 𝑖𝛼𝑑(𝜔𝜏𝑑)2−𝛼𝑑),
and shear mechanical function as:
𝑀𝐺𝐺∗ (𝜔) = ∑ ([𝑀𝑠
∗(𝜔)](𝝁−)𝑑+ ([𝑀𝑠
∗(𝜔)](𝝁+)𝑑
𝑛𝑚=1 )𝑚,
where
[𝑀𝑠∗(𝜔)](𝝁−)𝑠
= 𝑀∞ − ∆𝑀/(1 + 𝑖𝛼𝑠(𝜔𝜏𝑠)𝛼𝑠) ; [𝑀𝑠∗(𝜔)](𝝁+)𝑠
= ∆𝑀/(1 + 𝑖𝛼𝑠(𝜔𝜏𝑠)2−𝛼𝑠),
n number of subunits or subgroups or correlated clusters of molecular motion with differing time scales of
relaxations, where (0)n is Debye type dipole moment and n=1, 2, 3…, d and s are dielectric and shear
mechanical relaxation times. For each subunit dipole moment (0)n motion, unique intermolecular
interaction triggered non-Debye dipole moment ±()n=((1-d,s)0)n and ensuing dual dipole moment
(±)n=(0±(1-d,s)0)n is proposed in terms of Debye type dipole moment (0) to describe the non-Debye
relaxation process, where (+)n=((2-d,s)0)n, ()n=(d,s0)n and (d,s)n is an exponent 0<(d,s)n<1, and
signifies intermolecular interaction strength with a redistribution and conservation of Debye type
dielectric/mechanical loss and moment. Shear-mechanical and dielectric data analysis on the two simple
molecular glass formers 2-ethyl-1-hexanol and 2-butanol are presented based on the proposed model. The
shear-mechanical relaxation spectra show maximum of four Debye and their non-Debye processes around
Tg, which follow the typical scenario of a structural alpha relaxation and an additional Johari–Goldstein
beta, gamma and delta relaxations. The dielectric relaxation spectra are dominated by a Debye-type peak
with an additional three Debye and their non-Debye processes. The fragilities are reported based on the
mechanical alpha relaxation and the dielectric Debye-type process.
P-48 POSTER
Alc-HB
The Relation of Dielectric Relaxation with Translational
Diffusion for Typical Alcohols.
Tsubasa Kawaguchi(1)
, Yuki Hori(1)
, Rio Kita(1,2)
, Naoki Shinyashiki(1)
, Shin Yagihara
(1), Minoru Fukuzaki
(3)
(1) Department of Physics, School of Science, and
(2) Micro/Nano Technology Center, Tokai
University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa, 259-1292, Japan, (3)
Kumamoto Liberal
Arts Education Center, Tokai University, 9-1-1 Toroku, Higashi, Kumamoto, Kumamoto,
862-8652, Japan
There has not been an enough explanation on liquid structures of monohydric alcohols even
from extensive data obtained from dielectric relaxation measurements reported. Generally,
there is a large Debye-like process and a small -process, on the high frequency side than
Debye-like process, were exhibited1 on liquid state for monohydric alcohols. However, the
Debye-like process is not observed for poly-hydric alcohols. Although various models were
suggested to understand the presence of the Debye process in monohydric alcohols2, any
unequivocal evidences have not been yet presented. In this study, we aim to understand these
phenomena by comparing MHz and GHz region dielectric relaxation with translational
diffusion observed by Pulsed Field Gradient (PFG) NMR3 method. The diffusion coefficient
was respectively obtained for mono-, di-, and trihydric alcohols. A linear correlation between
diffusion coefficient and viscosity was understandably found for various alcohols. An
interesting result on a single straight line between the relaxation time for the -process of
dielectric relaxation and the diffusion coefficient was clearly shown for mono- and dihydric
alcohols, and even for water and typical organic solvents. However, the main process of
mono- and trihydric alcohols does not show such tendency. These results are indicated the -
process could consider as the processes that having same origin with diffusion coefficient for
these liquids. These facts might provide a knowledge to understand the origin of glycerol4
excess wing.
REFERENCES
1. Böhmer, R., et al., "Structure and dynamics of monohydroxy alcohols—milestones towards their
microscopic understanding, 100 years after Debye." Physics Reports, 545(4), 125-195 (2014)
2. Gainaru, C., et al., "Nuclear-magnetic-resonance measurements reveal the origin of the Debye process in
monohydroxy alcohols.", Physical Review Letters, 105(25), 258303 (2010)
3. Stejskal, Edward O., and John E. Tanner., "Spin diffusion measurements: spin echoes in the presence of a
time‐dependent field gradient.", The Journal of Chemical Physics, 42(1), 288-292 (1965)
4. Schneider, U., et al., "Excess wing in the dielectric loss of glass formers: A Johari-Goldstein β relaxation?.",
Physical Review Letters, 84(24), 5560 (2000)
POSTER P-49
Alc-HB
Thermal behavior of binary systems, water and methanol,
confined within porous materials
Toshiki Miyaoka1, Yoshiharu Ito
2, Atsushi Nagoe
3, and Hiroki Fujimori
1
1Graduate School of Integrated Basic Sciences, Nihon University, 3-25-40 Sakurajosui,
Setagaya-ku, Tokyo 156-8550, Japan
2School of Materials and Chemical Technology
Department of Materials Science and Engineering, Tokyo Institute of Technology University,
4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
3Department of Mathematics and Science, Science and Engineering, Kokushikan University,
4-28-1 Setagaya, Setagaya-ku, Tokyo 154-8515, Japan
Porous materials are expected a storage of materials and a utility of environmental
technology. It is known that physical properties of a solution confined within the porous
materials are different from that of the bulk solution. It is considered that the reasons are the
disappearance of the long-distance order structure and the appearance of the interfacial
tension between the solution and the pore walls. There is no problem when pure materials
confined within the pores, but when multi-component solutions confined within the pores, it
is necessary to pay attention to their composition in the pores.
In this study, we prepared methanol aqueous solutions at any composition and they were
confined within the pores at any filling rate against the pore volume. The fusion temperature
of water in them was measured using by differential scanning calorimetry (DSC).
As the results, it was found that the degree of the freezing point depression of the water
confined in the pores increased with increasing the concentration of methanol aqueous
solution and the filling rate. We will discuss the composition of the solution in the pores
based on the experimental results.
REFERENCES
1. A. Nagoe. et al. J. Phys.: Condens. Matter 27 (2015) 105101.
2. E. Tombaria. et al. Thermochimica Acta 492 (2009) 37–44.
P-50 POSTER
Alc-HB
Molecular Dynamics Simulations of Aqueous Mixtures in
Bulk and Confinement
Niels Müller and Micheal Vogel
Institut für Festkörperphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany
Binary mixtures of glass forming liquids have complex dynamical properties, including the
well documented plasticizer effect or changed temperature dependence compared to the
respective behavior of the neat liquids.1 This complexity is further increased in nanoscopic
confinements. For example MD simulations of ethylene-glycol water mixtures in silica-pores
revealed an unmixing near the pore wall and a change from non-Arrhenius to Arrhenius
temperature dependence.2
To single out the origin of these unusual behaviors we perform MD simulations of binary
mixtures composed of two water-like molecules with different polarity as a model system.
This way we obtain a binary mixture of high dynamic contrast, but minimal structural
differences of the mixed molecules. Through simulations in wide temperature and
concentration ranges we probe the plasticizer effect and multiple relaxation processes of these
systems. Detailed analyses yield insights into the dynamic arrest of the slower component and
resulting intrinsic confinement effects for the faster component. In addition, we confine these
model mixtures by walls formed by fixed molecules of one of the water-like species. In this
way, we systematically study the effect of the polarity of the confinement on mixtures of
hydrogen-bonded liquids. Performing spatially resolved analyses or selecting a subset of the
system, we gather detailed insights into the effects of confinement on the miscibility and
dynamics of these systems.
REFERENCES
1. B. Pötzschner, F. Mohamed, A. Lichtinger, D. Bock, and E. A. Rössler, Dynamics of asymmetric non-
polymeric binary glass formers—A nuclear magnetic resonance and dielectric spectroscopy study, J. Chem.
Phys. 143, 154506 (2015).
2. R. Schmitz, N. Müller, S. Ullmann, and M. Vogel, A molecular dynamics simulations study on ethylene
glycol-water mixtures in mesoporous silica, J. Chem. Phys. 145, 104703 (2016).
POSTER P-51
Ion-Por-Nano
Understanding of the exponential increase of the DC
conductivity in the chalcogenide glasses with increase of the
dopant content
Max Fraenkl1, Andrea Mandanici
2, Tomas Wagner
1
1 Department of General and Inorganic Chemistry, University of Pardubice,
Studentská 573, Pardubice 532 10, Czech Republic
2MIFT, Università di Messina, 98166 Messina, Italy
In the chalcogenide glasses there were observed exponential increase of the DC ionic
conductivity (as well increase of the diffusion coefficient) with increase of the dopant content
(Ag, Cu...). The region of the exponential increase is assigned to the dopant concentration
roughly between 3 at. % to 40 at. %. [1]. Origin of the phenomena was already studied and
modeled [2,3].
Author is driven by curiosity and would like to listed the parameters affecting the DC ionic
conductivity and discuss their relation to the exponential increase of the DC conductivity
mentioned above. The parameters are: (Distribution of Activation Energies, Ion-Ion
interaction, number of free sites in glassy matrix for dopant introduction, glassy matrix
changes induced by dopant introduction…).
REFERENCES
1. Adam, J.L. and X. Zhang, Chalcogenide Glasses. Chalcogenide Glasses. 2013. 1-682.
2. Roling, B., et al., Ionic ac and dc conductivities of glasses with varying modifier content. Journal of Non-
Crystalline Solids, 1998. 226(1-2): p. 138-144.
3. Elliott, S.R., Calculation of the activation energy for ionic conduction in glasses. Journal of Non-Crystalline
Solids, 1993. 160(1-2): p. 29-41.
P-52 POSTER
Ion-Por-Nano
Percolation in LiAlO2 Polymer-in-Ceramic Electrolytes
A. Greenbaum (Gutina)1, Yu. Feldman
1, R. Blanga
2, D. Golodnitsky
2
1Department of Applied Physics, The Hebrew University of Jerusalem, Jerusalem, 91904,
Israel
2School of Chemistry,
3Applied Materials Research Center, Tel Aviv University, Tel Aviv,
69978, Israel
Solid electrolytes could revolutionize battery and supercapacitor technology because of their
nontoxicity, stability during operation and enhanced safety. The major limitation of solid
electrolytes is their low ionic conductivity at room temperature. Our current study is focused
on the unravelling of the relaxation phenomena occurring in novel LiAlO2-pure ceramic
membrane and polymer-in-ceramic electrolytes over wide temperature (133K - 373K) and
frequency (1Hz – 1MHz) ranges. Dielectric measurements were performed using a BDS 80
Dielectric Spectrometer (NOVOCONTROL). The complex non-Debye dielectric response
can be described in terms of several distributed relaxation processes 1-4 separated by different
frequency and temperature ranges.
The low temperature relaxation process (below 280K) is observed for all the samples and can
be nicely described by Cole-Cole function. It most probably reflects the interaction of Li ions
with the matrix of composites. Another process shows the structural changes in the sample.
The material melting point is observed at high temperatures about 345 K. With increase of the
temperature, a well-pronounced process can be assigned to the Maxwell–Wagner polarization
mechanism typical for the porous materials. In this work, we will consider only the
percolation process occurring around room temperatures that will allow us to study a low
ionic conductivity effect of solid electrolytes complicated by grain-boundary phenomena.
Using our previously developed models1, it will also allow a porosity determination in such
systems.
REFERENCES
1. Gutina, A., Antropova, T., Rysiakiewicz-Pasek, E., Virnik, K., Feldman, Yu., Dielectric relaxation
in porous glasses, Microporous and Mesoporous Materials. 58, 237–254 (2003).
POSTER P-53
Cryst-Amor-GT
Influence of side chain packing on the main chain packing
in comb-like polymers with rigid backbones
Varun Danke,1 Tamoor Babur,
2 Gaurav Gupta,
1 Mario Beiner
1,2
1Fraunhofer-Institut für Mikrostruktur von Werkstoffen und Systemen IMWS
Walter-Hülse-Straße 1, 06120 Halle, Germany
2Martin-Luther-Universität Halle-Wittenberg, Naturwissenschaftliche Fakultät II
Heinrich-Damerow-Str. 4, 06120 Halle, Germany
Comb-like polymers with rigid backbones and flexible side chains are an important class of functional
materials with applications in various fields like organic semiconductors and light weight components
in high performance fiber composite materials with excellent mechanical properties. A common
feature of such comb-like polymers is the formation of layered structures with typical spacing in the 1-
3 nm range wherein the side chains (methylene sequences) aggregate to form alkyl nanodomains. The
packing of the methylene sequences within the alkyl nanodomains is of crucial importance for the
overall packing state which in turn can have a significant influence on the functional properties. In this
work we have investigated two series of such comb-like polymers, namely, poly (1,4-phenylene-2,5-n-
dialkyloxy terephthalate)s (PPAOTs) and poly (2,5-dialkyloxy-1,4-n-phenylene vinylene)s (AOPPVs)
having C=6 to C=12 carbon atoms in the side chain with the help of X-ray scattering and Dynamic
Mechanical Analysis (DMA). A novel approach of calculating the volume occupied by each
methylene unit (VCH2) within the alkyl nanodomains was employed (using the unit cell parameters
obtained from the crystallographic analysis) to predict the overall packing state of the side chains. A
large variation in the VCH2 (~30 %) values was observed between the crystalline/amorphous packing
states of the side chains for the different polymer series.1 While the PPAOTs series exhibited two
different polymorphic states namely modification A and modification B (for C > 8) corresponding to
the disordered or crystalline packing of the side chains respectively,2 the AOPPVs series exhibited
predominantly a crystalline packing of the side chains. Further, the crystalline packing of the side
chains in modification B for PPAOT led to a significant increase (~20 %) in the π-π stacking of the
backbones.2 Relaxation dynamics studies on modification A of the PPAOT series support the
existence of disordered alkyl nanodomains and confirm that the αPE dynamics of the methylene units is
primarily dependent on the alkyl nanodomains size.3
REFERENCES
1. Babur, T. et al., About different packing states of alkyl groups in comb-like polymers with rigid backbones,
Soft Matter 12, 8093-8097 (2016).
2. Gupta, G. et al., Interrelations between side chain and main chain packing in different crystal modifications
of alkoxylated polyesters, ACS Journal of Physical Chemistry B 121(17), 4583-4591 (2017).
3. Babur, T. et al., Confined relaxation dynamics in long range ordered polyesters with comb-like architecture,
Polymer 55, 6844-6852 (2014).
P-54 POSTER
Cryst-Amor-GT
The glass forming ability of ternary MnOx-SiO2-B2O3
system
P. Kupracz, M. Gazda, A. Lenaricak, M. Prześniak, J. Karczewski, N. A.
Wójcik, R. J. Barczyński,
Gdansk University of Technology, Narutowicza Street 11/12, 80-233 Gdansk, Poland
Glass containing high amount of transition metal oxides has a number of important properties
which make it potentially attractive for applications. These include reasonably high strength,
stiffness, hardness and wear resistance, chemical inertness, low thermal expansion coefficient
and high thermal conductivity. Moreover, most of that properties can be controlled by
concentration of transition metal ions on a different valence state [1-4].
One of promising material is a soda-silicate glass with high addition of manganese oxide,
which shows very high alkaline and moderate acid resistance. However, the chemical
resistance decreases with increase in alkaline oxide content. On the other hand, it is known
that decreasing of soda content increases melting temperature and increases a tendency to
separation between manganese and silicate rich phases [4].
In order to obtain a homogeneous glass showing high mechanical and chemical durability,
with moderate melting temperature, a new glass composition containing over 50 mol% of
MnO was proposed. The obtained glass was homogeneous, has high chemical resistance and
melting temperature below 1100oC. Its electrical, magnetic and thermal properties, as the
structure, were measured and they show very interesting properties like increase in
conductivity after heat treatment below the glass transition temperature, a separation of
amorphous SiO2-rich and MnO-rich phases and formation of the spin glass state at
temperature below 8K.
REFERENCES
1. Paul, A., Youssefi, A.,. Alkaline durability of some silicate glasses containing CaO, FeO and MnO. Journal
of Materials Science 13, 97–107 (1978).
2. McMillan, P.W., n.d. The preparation and properties of glasses containing major proportions of certain
transition metal oxides 333–317.
3. Hamilton, E.H., Waxler, R.M., Nivert, J.M.,. Properties of zinc borosilicate glasses. Journal of Research of
the Notional Bureau of Standards 62. doi:10.6028/jres.062.011 (1959)
4. Ehrt, D., Zinc and manganese borate glasses – phase separation, crystallisation, photoluminescence and
structure. European Journal of Glass Science and Technology Part B Physics and Chemistry of Glasses 54,
65–75 (2013).
POSTER P-55
Cryst-Amor-GT
Critical nucleus size for crystallization of a supercooled
liquid in two dimensions
Tomoko Mizuguchi1*
, Yuki Higeta2, and Takashi Odagaki
2
1Institute for the Promotion of University Strategy, Kyoto Institute of Technology,
Kyoto 606-8585, Japan
2Division of Science, School of Science and Engineering, Tokyo Denki University,
Hatoyama, Saitama 350-0394, Japan
We present a study of crystallization of a supercooled liquid using a simple model in two
dimensions by means of molecular dynamics simulations. The model system is characterized
by a spherical interaction potential of the form
2
26
0
12
00
2
)(exp2)(
Grr
r
r
r
rrV
We investigate the time evolution of a discoidal crystal seed embedded in the supercooled
liquid, and determine the critical nucleus size nc defined as the smallest nucleus which
survives. The results show that nc scales as ~ Tm -T( )-2
with the melting temperature Tm, as
expected in the classical nucleation theory. We also investigate effects of the crystal seed on
the crystallization time of the system, and show that the presence of the seed significantly
affects the crystallization time when the temperature is higher than the characteristic
temperature T* at which the crystallization time becomes the shortest. When the temperature
is lower than T*, on the other hand, the effect of the seed on crystallization is less significant.
These results reflect the difference of crystallization mechanism in the temperature range
T > T* and that in T < T*. Namely, the growth of a nucleus dominate in T > T*, whereas the
merging of small nuclei dominate in T < T*.
REFERENCES
1. Mizuguchi, T., Higeta, Y., Odagaki, T., Critical nucleus size for crystallization of supercooled liquids in
two dimensions, Phys. Rev. E (in press).
2. Mizuguchi, T., Odagaki, T., Glass formation and crystallization of a simple monatomic liquid, Phys. Rev. E
79, 051501 (2009).
P-56 POSTER
Cryst-Amor-GT
Success of CNT and the emergence of twinned structures in
Lennard-Jones droplet freezing
S.M. Malek1, G.P. Morrow
1, I. Saika-Voivod
1
1Department of Physics and Physical Oceanography, Memorial University of Newfoundland,
St. John’s, NL, Canada
We carry out molecular dynamics (MD) and Monte Carlo (MC) simulations to characterize
nucleation in liquid clusters of 600 Lennard-Jones particles over a broad range of
temperatures. We use the formalism of mean first-passage times (MFPT) to determine the rate
and find that Classical Nucleation Theory (CNT) predicts the rate quite well, even when
employing simple modelling of crystallite shape, chemical potential, surface tension and
particle attachment rate, down to the temperature where the droplet loses metastability and
crystallization proceeds through growth-limited nucleation in an unequilibrated liquid. Below
this crossover temperature, the nucleation rate is still predicted when MC simulations are used
to directly calculate quantities required by CNT. Discrepancy in critical embryo sizes
obtained from MD and MC arises when twinned structures with five-fold symmetry provide a
competing free energy pathway out of the critical region. We find that crystallization begins
with hcp-fcc stacked precritical nuclei and differentiation to various final structures occurs
when these embryos become critical. Differences in the way the different structures are
sampled in equilibrium (MC) and during steady-state nucleation (MD) lead to difficulty in
using MFTP to recover the free energy landscape. We confirm that using the largest embryo
in the system as a reaction coordinate is useful in determining the onset of growth-limited
nucleation and show that it gives the same free energy barriers as the full cluster size
distribution once the proper reference state is identified. We find that the bulk melting
temperature controls the rate, even though the solid-liquid coexistence temperature for the
droplet is significantly lower. The value of surface tension that renders close agreement
between CNT and direct rate determination is significantly lower than what is expected for
the bulk system.
REFERENCES
1. Malek, S.M.A., Morrow, G.P., and Saika-Voivod, I., Crystallization of Lennard-Jones
nanodroplets: From near melting to deeply supercooled, J. Chem. Phys. 142, 124506 (2015).
POSTER P-57
Cryst-Amor-GT
IR-studies of thermally stimulated structural phase
transformations in cryovacuum deposited films of Freon
134A
Aldiyarov Abdurakhman, Drobyshev Andrey, Nurmukan Assel,
Sokolov Dmitriy, Shinbayeva Ainura
al-Farabi Kazakh National University
Scientific Research Institute of Experimental and Theoretical Physics,
71 al-Farabi ave., Almaty, Kazakhstan
The need to ensure the environmental safety of modern production requires the search for new
technologies and working substances that cause minimal damage to the environment. An
example of this is the use, as refrigerant, of Freon 134 or its isomer 134a, which replaces the
environmentally problemous chlorofluorocarbon CF2Cl2. Refrigerant Freon 134 is
increasingly used in domestic and industrial air conditioners, also in the aerospace industry.
This circumstance requires more detailed information about its fundamental chemical and
physical characteristics-thermodynamic properties, optical absorption spectra, etc., which can
be directly used in solving a wide range of applied problems. And if these properties of Freon
134 in the gaseous phase was studied in sufficient detail, its thermophysical and optical
characteristics in a condensed state at low temperatures have not been practically studied.
In this work, the objects of investigation are thin films of freon cryovacuum condensates
condensed on a cooled metal mirror in a range of deposition temperatures from 16 to 100 K
and pressures of the gas phase from 10-4
to 10-6
Torr. The thickness of the films was measured
by a two-beam laser interferometer and amounted to d = 2.5 μm. At the same time, refractive
index of the condensed samples was measured. IR absorption spectrum was measured in the
frequency range of 400 cm-1
- 4200 cm-1
. In detail, the experimental setup and the
measurement technique are described by us in earlier publications [1, 2].
REFERENCES
1. Drobyshev A., and others, Transformation of cryovacuum condensates of ethanol near the glass transition
temperature, Low Temperature Physics. V.39, №8, 714-718 (2013).
2. Drobyshev A., and others, Physical modeling of the formation of clathrate hydrates of methane, Low
Temperature Physics. V.41 №6, 552-558 (2015).
P-58 POSTER
Cryst-Amor-GT
Synthesis and evaluate of aluminium titanate and glass
composite ceramics
Mao Sunaga1, Daisuke Yokota
1, Takayuki Sugimoto
1, and Hiroki Fujimori
1
1Graduate School of Integrated Basic Sciences, Nihon University,
3-25-40 Sakurajosui, Setagaya-ku, Tokyo 156-8550, Japan
Aluminium titanate (Al2TiO5) is one of ceramics materials which exhibits interesting
properties, such as a low thermal expansion, a high melting point, and a high thermal shock
resistance. The low thermal expansion is lead to microcracks to cause by thermal expansion
anisotropy. This microcrack lowers the strength of the materials. We noticed an amorphous
glass as the disperse phase to fill the microcracks. In this study, Al2TiO5 was evaluated the
manufacturing process, because Al2TiO5 changed the mechanical properties by the process,
and the aluminium titanate-glass composite ceramics were synthesized and evaluated the
physical properties.
POSTER P-59
Cryst-Amor-GT
Influence of cation n-alkyl side chain length on the
crystallization tendency of a family of ionic liquids
[CnMPyrr]+[Tf2N]
− (n=4,5,6,8)
Grzegorz Szklarz1,2
, Karolina Adrjanowicz1,2
, Marian Paluch1,2
1 Institute of Physics, University of Silesia, ul. Uniwersytecka 4, 40-007 Katowice,
Poland
2 Silesian Center for Education and Interdisciplinary Research, 75 Pulku Piechoty 1a,
41-500 Chorzow, Poland
Nowadays, ionic liquids are deeply investigated due to their unique physical and chemical
properties and their potential application in technology and chemistry. Ionic liquid are
composed of an organic cation (e.g. N-methyl-N-methylpyrrolidinium) and by inorganic or
organic anion (e.g. chloride, bis(trifluoromethansulfonyl)imide). Moreover, properties of
ionic liquids, like a electrochemical window, conductivity, thermal stability and glass forming
ability strongly vary with change of used cation or anion.
In our study we are focusing on crystallization kinetics of supercooled ionic liquids at
isothermal and non-isothermal conditions. In this purpose we chose four representatives ionic
liquids from the family N-alkyl-N-methylpyrrolidinium bis(trifluoromethansulfonyl)imide
([CnMPyrr]+ [Tf2N]
−), which have moderate length non-polar n-alkyl side chain in cation
([C4MPyrr]+[Tf2N]
−, [C5MPyrr]
+[Tf2N]
−, [C6MPyrr]
+[Tf2N]
−, [C8MPyrr]
+[Tf2N]
−). Our
studies shows, these slight changes of cation structure have a big impact on crystallization
process and furthermore other physical properties. These findings can help predict behavior of
ionic liquids below melting temperature and can play a critical role in selection of ionic
liquids in electric energy storage systems.
P-60 POSTER
AM-Pharm
Innovative approach to determine the stable concentration
of the drug-polymer mixtures. Demonstrated on the
example of antiandrogen drug - Flutamide
K. Chmiel 1,2
, J. Knapik-Kowalczuk 1,2
, K. Jurkiewicz 1,2
and M. Paluch 1,2
1Institute of Physics, University of Silesia, ul. Uniwersytecka 4, 40-007 Katowice, Poland
2SMCEBI, ul. 75 Pułku Piechoty 1a, 41-500 Chorzów, Poland
On the poster a novel approach to determine stable concentration in API-polymer
systems will be presented. As a model binary amorphous mixtures flutamied (FL) drug with a
co-polymer Kollidon VA64 (PVP/VA) has been used. It is worth to note that the finding an
effective method to achieve this goal is a matter of great importance since physical stability of
the amorphous pharmaceuticals is the key issue investigated worldwide1. Due to the fact that
molecular dynamics was found to be crucial factor affecting physical stability of disordered
pharmaceuticals2,3
, we examined it for both neat FL and its PVP?VA mixtures by means of
Broadband Dielectric Spectroscopy (BDS). Thorough investigation of the impact of
polymeric additive on the molecular mobility of disordered FL, reviles unusual, previously
un-reported behavior. Namely, simultaneously with the beginning of the crystallization
process, we observe some transformation from unstable supersaturated concentration of
investigated mixture to the different, unknown concentration of FL-PVP/VA. Observed,
during BDS experiment, transformation enables us to determine the limiting, highly
physically stable concentration of FL in PVP/VA polymer (saturated solution), which is
equivalent to FL + 41% wt. of PVP/VA. Described high physical stability of this unveiled
system has been confirmed by means of long-term XRD measurements. According to our
knowledge this is the first time when such a behavior has been observed by means of BDS.
REFERENCES
1. Grzybowska, K.; Capaccioli, S.; Paluch, M. Recent Developments in the Experimental Investigations of
Relaxations in Pharmaceuticals by Dielectric Techniques at Ambient and Elevated Pressure. Adv. Drug
Delivery Rev.100, 158−182 (2016).
2. Bhardwaj, S. P.; Suryanarayanan, R. Molecular Mobility as an Effective Predictor of the Physical Stability
of Amorphous Trehalose. Mol. Pharmaceutics , 9 (11), 3209−3217. (2012)
3. Bhardwaj, S. P.; Arora, K. K.; Kwong, E.; Templeton, A.; Clas, S. D.; Suryanarayanan, R. Correlation
between molecular mobility and physical stability of amorphous itraconazole. Mol. Pharmaceutics 10,
694−700. (2013)
POSTER P-61
AM-Pharm
Crystal growth of different polymorphic forms of
nifedipine and naproxene from binary mixtures above and
below the glass transition temperature using various
experimental techniques
O. Madejczyk1,2
, E. Kaminska3, M. Tarnacka
1,2, M. Dulski
4,
K. Jurkiewicz1,2
, K. Kaminski1,2, M. Paluch
1,2
1Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland
2Silesian Center for Education and Interdisciplinary Research, University of Silesia, 75 Pulku
Piechoty 1A, 41-500 Chorzow, Poland
3Department of Pharmacognosy and Phytochemistry, Medical University of Silesia in
Katowice, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec,
Jagiellonska 4, 41-200 Sosnowiec, Poland
4Institute of Material Science, University of Silesia, 75 Pulku Piechoty 1a, 41-500 Chorzow,
Poland
The crystal growth of nifedipine and naproxen from pure system and from binary mixtures composed
of active substance (API) and two acetylated disaccharides: maltose and sucrose was investigated with
the use of X-Ray diffraction (XRD) Broadband Dielectric Spectroscopy (BDS), Differential Scanning
Calorimetry (DSC), optical microscope above and below the glass transition temperature. It was found
that the morphology of growing crystals strongly depends on the presence of modified carbohydrates
and temperature conditions. It was shown that for given τα the growth of crystals is the fastest in pure
API. On the other hand, the most significant slowing down of this process is noted for binary mixtures
composed of API and modified maltose. Most likely it is due to stronger dipole-dipole interactions in
these systems Furthermore, it has been shown that above the glass transition temperature a strong
decoupling between crystal growth and reorientational dynamics is observed. Interestingly both
quantities becomes more coupled below the Tg. This experimental data enable better understanding of
the interrelation between crystal growth rate and structural relaxation process above and below the
glass transition temperature.
REFERENCES
1. KAMINSKA, E., MADEJCZYK, O., TARNACKA, M., JURKIEWICZ, K., KAMINSKI, K., PALUCH,
M., Studying of crystal growth and overall crystallization of naproxen from binary mixtures, Eur. J. Pharm.
Biopharm. 113, 75-87 (2017).
2. MADEJCZYK, O., KAMINSKA, E., TARNACKA, M., DULSKI, M., JURKIEWICZ, K., KAMINSKI, K.,
PALUCH, M., Studying the crystallization of various polymorphic forms of nifedipine from binary mixtures
with the use of different experimental techniques, under review Mol. Pharm.
P-62 POSTER
AM-Pharm
Molecular Dynamics, Recrystallization Behavior and Water
Solubility of the Amorphous Anticancer Agent
Bicalutamide and Its Polyvinylpyrrolidone Mixtures
Justyna Szczurek,1,2
Marzena Rams-Baron, 1 ,2
Justyna Knapik-Kowalczuk, 1 ,2
Agata Antosik, 3
Joanna Szafraniec, 3
Witold Jamróz, 3
Mateusz Dulski, 4
Renata Jachowicz, 3
and Marian Paluch1,2
1 Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland
2 Silesian Center for Education and Interdisciplinary Research, 75 Pulku Piechoty 1A, 41-500
Chorzow, Poland
3 Jagiellonian University, Faculty of Pharmacy, Department of Pharmaceutical Technology
and Biopharmaceutics, Medyczna 9, 30-688 Kraków, Poland
4 Institute of Materials Science, University of Silesia, 75 Pulku Piechoty 1A, 41-500
Chorzow, Poland
Bicalutamide is an anticancer drug used to prostate cancer treatment. According to Biopharmaceutical
System (BCS)1 it is classified as BCS II class because of its poor water solubility and limited
permeability. Our studies have shown that bicalutamide in amorphous form has a strong tendency to
crystallize. In order to improve the stability of drug in the glassy state and improve its water solubility,
we prepared a drug-polymer binary system with polyvinylpyrrolidone. The results of the broadband
dielectric spectroscopy and differential scanning calorimetry measurements have shown that the
polymer addition increases the physical stability of the drug and is associated, among others, with the
downturn of molecular dynamics. In addition, the crystallization inhibition was also influenced by the
specific interactions between polymer and bicalutamide, whose presence has been confirmed by
Fourier transform infrared spectroscopy studies. Completely inhibited crystallization was observed for
binary mixture in weight ratio BIC-PVP 2-1. Molecular dynamics is also considered as important
factor in crystallization process. Based on that, we have estimated the long-term stability of
bicalutamide blends with polymer at room temperature. For a mixture of BIC-PVP in ratio 2-1, we
predicted that crystallization would be inhibited for 146 years. Moreover, we have performed
solubility and dissolution studies which have shown that the addition of a polymer increases the
solubility of the mixture by approximately 37 times compared to pure amorphous bicalutamide. Such
improved physical properties of bicalutamide indicate the possibility of using the analyzed binary
mixtures in the pharmaceutical industry.
REFERENCES
1. Kanfer, I. Report on the International Workshop on the Biopharmaceutics Classification System
(BCS): Scientific and regulatory aspects in practice. J. Pharm. Pharm. Sci., 5 (1), 1−4, (2002).
POSTER P-63
AM-Pharm
Amorphous Protic Ionic Systems as Promising Active
Pharmaceutical Ingredients: The case of Sumatriptan Drug
Z. Wojnarowska, M. Paluch
1University of Silesia in Katowice, Institute of Physics, Uniwersytecka 4, 40-007 Katowice
In this presentation we highlight the benefits coming from the application of
amorphous protic ionic systems as active pharmaceutical ingredients (APIs). Using the case
of sumatriptan (STR) drug we show that the conversion of non-ionic API to partially ionized
amorphous succinate salt (STR SUCC) brings a substantial improvement in apparent
solubility. Since in general the disordered systems reveal a tendency to self-arrangement
during storage the dominant part of this paper is dedicated to the physical stability issue of
sumatriptan and its ionic counterpart. To recognize the crystallization tendency of the studied
systems the molecular/ions mobility, usually considered as the most critical factor governing
the spontaneous nucleation process from the amorphous and supercooled state, is discussed.
Analysis of dielectric response of ionic and non-ionic sumatriptan complemented by
calorimetric measurements reveals many similarities in relaxation dynamics and thermal
properties of these APIs as well as distinct differences in their resistance against
crystallization in the supercooled liquid state. To determine the long-term physical stability of
these materials at room temperature conditions the time scale of structural relaxation below
their glass transition temperatures are estimated. We show that in contrast to non-ionic
materials τα predictions of STR SUCC are much more complex and require aging
experiments.
ACKNOWLEDGEMENT
Authors are deeply grateful for the financial support by the National Science Centre within
the framework of the Symfonia3 project (Grant No. 2015/16/W/NZ7/00404).
REFERENCES
1. Wojnarowska, Z. et all Amorphous Protic Ionic Systems as Promising Active Pharmaceutical Ingredients:
The Case of the Sumatriptan Succinate Drug Mol. Pharm. 13 (3), 1111–1122 (2016)
2. Paluch, M. Dielectric properties of ionic liquids, Springer: Berlin (2016).
P-64 POSTER
Cryst-Amor-GT
Frustration of crystallisation by a liquid–crystal phase
Christopher D. Syme,a Joanna Mosses,
a Mario González Jiménez,
a Olga
Shebanova,b Finlay Walton,
a and Klaas Wynne
a,*
a School of Chemistry, WestCHEM, University of Glasgow, UK,
b Diamond Light Source, Harwell Science and Innovation Campus, Oxfordshire, UK
Frustration of crystallisation by locally favoured structures is critically important in linking
the phenomena of supercooling, glass formation, and liquid-liquid transitions. Here we show
that the putative liquid-liquid transition in n-butanol is in fact caused by geometric frustration
associated with an isotropic to rippled lamellar liquid-crystal transition. 1
Liquid-crystal
phases are generally regarded as being “in between” the liquid and the crystalline state. In
contrast, the liquid-crystal phase in supercooled n-butanol is found to inhibit the
transformation to the crystal. The observed frustrated phase is a template for similar ordering
in other liquids and likely to play an important role in the supercooling and liquid-liquid
transitions 2
in many other molecular liquids.
REFERENCES
1. Syme, C. D. et al. Frustration of crystallisation by a liquid–crystal phase. Sci. Rep. 7, 42439 (2017).
2. Mosses, J., Syme, C. D. & Wynne, K. Order Parameter of the Liquid–Liquid Transition in a Molecular
Liquid. J Phys Chem Lett 6, 38-43 (2015).
POSTER P-65
Cryst-Amor-GT
Modification of Fast Scanning Calorimetry for ultra-fast
cooling close to surrounding gas temperature for study of
polymer crystallization
Evgeny Zhuravlev1,2
, Jing Jiang1, Dongshan Zhou
1,3, Christoph Schick
2,
Gi Xue1
1. Department of Polymer Science and Engineering, School of Chemistry and
Chemical Engineering, Nanjing University, Nanjing 210093
2. Institute of Physics, Rostock University, Rostock 18051
3. Shenzhen R.&D. Center, State Key Laboratory of Coordination Chemistry, Nanjing
University, Shenzhen 518057
Polymer crystallization in the vicinity of glass transition still remains the point of large
controversy [1]. Time and size of the involved rearrangements places certain challenge for
instrumentation and experimental design. Fast Scanning Calorimetry (FSC) introduced by [2]
brought vast possibilities for polymer vitrification and crystallization study. It can follow up
crystallization/vitrification at cooling rates up to 1,000,000 K/s under condition of liquid
nitrogen cooled gas environment. Separation of heat treatment and analysis temperature scans
gives even more opportunities e.g. for crystal nucleation rate measurement [3].
Recently a combination with other structural techniques gained interest (see lecture session).
But liquid nitrogen cooled atmosphere benefit of the FSC restricts it’s combination, e.g. with
AFM or optical microscope. Cooling in FSC realized by surrounding gas. And it can be very
fast when the difference between sample and surrounding gas is over 100 K. But ballistic
cooling reduces cooling rate performance near base temperature to an unacceptable level.
Taking advantage of multi-stage experiments, where the heat treatment step doesn’t require
precise in-situ measurement, gas cooling can be replaced by less controlled but much more
efficient liquid cooling. Which is especially important for large samples. A solution
significantly improving cooling performance of FSC close to base temperature is suggested
and realized on example of polyethylene crystallization.
REFERENCES
1. Androsch, R., Zhuravlev, E., and Schick, C., Solid-state reorganization, melting and melt-recrystallization of
conformationally disordered crystals (α′-phase) of poly (l-lactic acid). Polymer,. 55: p. 4932-4941 (2014).
2. Zhuravlev, E. and Schick, C., Fast scanning power compensated differential scanning nano-calorimeter: 2. Heat
capacity analysis. Thermochimica Acta,. 505(1-2): p. 14-21 (2010).
3. Zhuravlev, E., et al., Experimental test of Tammann’s nuclei development approach in crystallization of
macromolecules. Crystal Growth & Design,. 15(2): p. 786-798 (2015).
P-66 POSTER
Dyn-Biomol
Evidence of Coupling between the Motions of Water and
Peptides
Izaskun Combarro-Palacios*, Jan Swenson§ and Silvina Cerveny
†,‡
†Centro de Fisica de Materiales (CSIC, UPV/EHU)-Materials Physics Center (MPC), Paseo
Manuel de Lardizabal 5, 20018 San Sebastián, Spain
‡Donostia International Physics Center, 20018 San Sebastián, Spain
*Departamento de Física de Materiales (UPV/EHU), Apartado 1072, 20080 San Sebastián,
Spain
§Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg,
Sweden
The number of studies related with hydrated proteins is numerous but despite of this, the role
of water is not clear enough. Moreover, the major problem of the dynamical studies on
proteins is its low solubility degree. Due to this, to obtain a proper protein solution, a large
quantity of water is necessary which crystallizes on cooling, masking the dielectric signal of
the protein itself and hindering the dynamic study. Therefore, most studies are carried out on
hydrated powders instead of well-diluted solutions which represent more realistic cases.
Here, we avoid the problem of crystallization by reducing the size of the biomolecules. We
have studied oligomers of the amino acid n-lysine oligomers, fully dissolved in water. The
dielectric relaxation data show that the glass transition-related dynamics of the oligomers is
determined by the water dynamics, in a way similar to that previously observed for solvated
proteins: above the glass transition temperature, the protein motions follow the same
temperature dependence as the surrounding water molecules. According to this, a coupling
between the solute and the solvent dynamics can be defined, describing the motion of
oligomers as being “slaved” to that of the solvents surrounding the solute molecules. This
implies that the crucial role of water for protein dynamics can be extended to other types of
macromolecular systems, where water is also able to determine their conformational
fluctuations.
REFERENCES
1. Cerveny, S.; Combarro-Palacios, I.; Swenson, J., Evidence of Coupling between the Motions of Water and
Peptides. The Journal of Physical Chemistry Letters 7, 4093-4098 (2016)
POSTER P-67
Dyn-Biomol
Water dynamics confined in synthetic Al-substituted
Tobermorite
Guido Goracci1, Marta Díez-Garcia
2, José I. Santos
3, Izaskun Combarro-
Palacios5, Gustavo A. Schwartz
1, Jorge S. Dolado
2, Juan J. Gaitero
2 and
Silvina Cerveny1, 4
1Centro de Fisica de Materiales (CSIC, UPV/EHU)-Materials Physics Center (MPC), Paseo
Manuel de Lardizabal 5, 20018 San Sebastián, Spain
2 Sustainable Construction Division Tecnalia Parque tecnologico de Bizkaia C/Geldo, Edif.
700, 48160 Derio, Spain
3 NMR Facility, SGIKER, Universidad del País Vasco (UPV/EHU), Joxe Mari Korta Zentroa,
Tolosa Hiribidea 72, San Sebastián 20018, Spain
3Donostia International Physics Center, 20018 San Sebastián, Spain
5Departamento de Física de Materiales (UPV/EHU), Apartado 1072, 20080 San Sebastián,
Spain
E-mail: [email protected]
The main phase of the hydrated cement paste is the calcium silicate hydrate (C-S-H). Many
features of such gel phase depend on the relation between its pore network and the water
molecules confined inside it. However, C-S-H has a complex heterogeneous nanostructure.
Therefore, tobermorite-like chains are used as a model to produce the interlayer nano-pores in molecular dynamical simulations of C-S-H.
In this work, we have investigated the dynamics of water molecules confined in zeolite-like
cavities of synthetic tobermorite as well as the structure of the confinement. Samples were
prepared with different aluminum content in order to study the effects of Al-substitution on the
structure of tobermorite and, as a consequence, on the different confinements explored by the
water molecules trapped in. From the structural side, two different phases have been found in the
tobermorite: an amorphous phase and a crystalline phase. Their content in the specimens depend
on the Al amount remarking the important role of aluminum for the tobermorite crystallization. In
addition, water dynamics have been studied by means of broadband dielectric spectroscopy in the
sub-zero region (95 – 170 K) where confinement effects on the supercooled water dynamics can
be observed. Two different dynamics (fast and slow) have been observed in all the samples. The
slow dynamics properties depend on the type of confinement: in the Al-free samples, i.e.
amorphous tobermorite, such dynamics strongly reminds that of water confined in the C-S-H
framework. The fast dynamics have been related to the rotation of the OH groups in the crystalline tobemorite.
REFERENCES
1. Cerveny, Silvina, et al. "Effect of hydration on the dielectric properties of CSH gel." The Journal of chemical
physics 134.3 (2011): 034509.
2. Monasterio, Manuel, et al. "Effect of Chemical Environment on the Dynamics of Water Confined in Calcium
Silicate Minerals: Natural and Synthetic Tobermorite." Langmuir 31.17 (2015): 4964-4972.
P-68 POSTER
Dyn-Biomol
Model on anomalous temperature dependence of dielectric
relaxation intensity of hydration water
Masahiro Nakanishi
Fukuoka Institute of Technology, Faculty of Engineering, Department of Electrical
Engineering, 3-30-1 Wajiro-higashi, Higashi-ku, Fukuoka 811-0295, Japan
Water is indispensable for biological functionality and its interaction with biological
molecules provides key knowledge for understanding the physics of biological materials.
Since water is a polar molecule, dielectric spectroscopy, which probes reorientational
relaxation dynamics of polar molecules, has been extensively employed to study hydrated
protein systems 1. Although the relaxation process corresponding to hydration water has been
assigned from dielectric spectra, its microscopic details are not yet clarified.
In the present work, I propose a microscopic model to explain temperature dependence
of dielectric relaxation intensity Δε. Earlier experimental studies reported that the relaxation
intensity of the hydration water process decreases with decreasing temperature 2. This
dependence is quite anomalous compared to normal dependence 3, wherein the relaxation
intensity increases with decreasing temperature. Assuming directional bonding of water
molecules to host biological matrices and free energy difference between bonded and
unbonded states (ΔF), I obtained Δε ~ exp(–ΔF/kBT), where T and kB denote temperature and
Boltzmann constant, respectively. This equation successfully describes the anomalous
temperature dependence of the hydration water process. The source of the anomalous
temperature dependence in the model is the antiparallel orientational correlation intermediated
by matrix molecules. The free energy difference between bonded and unbonded states is
obtained as a fit parameter when this model is applied to experimental data. The details of the
models and its comparisons to experimental data are further outlined in the poster.
REFERENCES
1. Ngai, K. L., Capaccioli, S., Ancherbak, S., Shinyashiki, N., Resolving the ambiguity of the dynamics of
water and clarifying its role in hydrated proteins, Phil. Mag. 91, 1809–1835 (2011).
2. Nakanishi, M., Sokolov, A. P., Protein dynamics in a broad frequency range: Dielectric spectroscopy
studies, J. Non-Cryst. Solid. 407, 478–485 (2015).
3. Fröhlich, H., Theory of Dielectrics, Oxford Univ. Press (1958).
POSTER P-69
Dyn-Biomol
Microscopic dynamics and Thermodynamic Properties of
Bioprotective Glycine Betaine Solutions
Noriko Onoda-Yamamuro1, Keita Okada
1, Yusuke Osawa
1, Shinichi Tajima
1,
Kazuki Takazawa1, Tatsuya Kikuchi
2, Maiko Kofu
3, and Osamu Yamamuro
3
1College of Science and Engineering, Tokyo Denki University, Saitama 350-0394, Japan
2Neutron Science Section, J-PARC Center, Tokai, Ibaraki 319-1195, Japan
3Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
Glycine betaine [GB: (CH3)3N+CH2COO
−] is a zwitterionic compound which has negative
and positive charges in a molecule. This compound is known to exhibit a "bioprotective"
function in crop plants under extreme environmental conditions, such as drought. The
protection mechanism of GB is probably different from that of trehalose, a bioprotective
disaccharide, which shows marked destructuring effects on hydrogen-bond networks of water
in some kinds of animals. We have studied the ps to ns dynamics of water and GB molecules
in GB solutions by using quasi-elastic neutron scattering (QENS) techniques with AGNES
(ISSP, JRR-3, Japan) and IN5 (ILL, France) spectrometers. To observe the diffusive motions
of GB and water molecules separately, we measured both d-GB/H2O and h-GB/D2O
solutions; the hydrogenated part is preferentially observed. We have also studied
thermodynamic properties of this system by using an adiabatic calorimeter for simultaneous
measurement of enthalpy and volume.
By assuming simple diffusion processes, the self-diffusion coefficient Ds of water and GB
molecules were obtained from the Q-dependence of the peak-widths of the dynamic structure
factors of d-GB/H2O and h-GB/D2O, respectively. The Ds of water and GB molecules
become smaller and tend to have closer values with increasing the GB concentration. The
activation enthalpies of the diffusions of water and GB molecules were obtained by the
temperature dependence of Ds. They have similar values (17.0 and 16.4 kJ mol-1
,
respectively) at x = 0.1. The cooperative diffusion of water and GB molecules at higher GB
concentrations (x > 0.1) was confirmed also by the mode-distribution analysis [1]. We
speculate that some sort of hydration structure (e.g. clathrate-like structure) is built in the GB
solution and the bioprotectice function is deeply related to that. Thermodynamic analysis
based on heat capacity and volume measurements are now in progress.
REFERENCES
1. Kikuchi, T., et.al, Mode-distribution analysis of quasielastic neutron scattering and application to liquid
water, Phys. Rev. E 87, 062314 (2013).
P-70 POSTER
Dyn-Biomol
Vibrational dynamics of biomolecules in non-aqueous
glassy matrices
Maria Pachettia, Alessandro Paciaroni
b, Simone Capaccioli
a, Giovanni
Birardac, Lisa Vaccari
c
aDipartimento di Fisica, Università di Pisa, Largo Bruno Pontecorvo 3 ,I-56127, Pisa, Italy
bDipartimento di Fisica, Università di Perugia, Via A. Pascoli 1, 06123 Perugia, Italy
cElettra Sincrotrone Trieste, Area Science Park SS14, Km 163.5, 34149, Basovizza, Italy
Biomolecules may have different and complicated structures and dynamics, strongly related to their
function. Hence, a biomolecule can perform its functions only if its native structure and dynamics do
not change upon external perturbations, and viceversa [1]. For example, if a protein is stored as a
lyophilized system without any excipient, its native structure turns to be destroyed or modified
irreversibly by the freeze-drying process [2, 3]. To improve their long-term storage capability and the
stability of their native structure, biomolecules are stored as lyophilized mixtures in presence of
glassy H-bonded matrices [4]. For this reason, saccharides and polyols are usually added to the
formulation to preserve the native structure of biomolecules, protecting them from the stresses due to
the removal of water [2], increasing the mixtures stability because of their higher viscosities compared
to water.
In the present work we have studied lysozyme embedded in different bioprotectant matrices, such as
sugars and polyols, obtained from freeze-drying procedure.
Mid-Infrared spectroscopy is very sensitive to the modification of the secondary structure of
biomolecules, allowing us to quantify these changes, in respect to variations in the temperature and in
solvent [5], and showing the real bioprotection exerted by the glassy matrix used. In particular, after
lyophilization and at ambient temperature, it has been observed a decreasing of the -helix population
depending on the solvent used as bioprotectors and a simultaneous augmentation of the other
secondary structures. Moreover, increasing temperature towards denaturation, the modification of the
secondary structure becomes stronger with a further destabilization of the native -helix population in
favour of -sheets and random structures. Aknowledgements: we thank the CERIC-ERIC Consortium
for the access to experimental facilities and financial support.
References
1. Fenimore P. W., Frauenfelder H., McMahon B. H., Young R. D., “Bulk-solvent and hydration-shell fluctuations,
similar to - and -fluctuations in glasses, control protein motions and functions”, Proc. Natl. Acad. Sci. USA. 101,
14408–14413 (2004).
2. Carpenter J.F., Crowe J.H, “An infrared spectroscopic study of the interactions of carbohydrates with dried proteins”,
Biochem. J. 28, 3916-3922 (1989).
3. Petrelski S. J., Pikal K. A., Arakawa T., “Optimization of lyophilisation conditions for recombinant human interleukin-2
by dried-state conformational analysis using Fourier-Transform Infrared Spectroscopy”, Pharm. Res. 12, 1250-1259
(1995).
4. Allison S.D., Chang B., Randolph T.W., Carpenter J.F., “Hydrogen bonding between sugar and protein is
responsible for inhibition of dehydration-induced protein unfolding”, Arch. Biochem. Biophys. 365, 289-298 (1999).
5. Dong A., Huang P., Caughey W. S., “Protein secondary structures in water from second-derivative amide I infrared
spectra”, Biochem. 29, 3303-3308 (1990).
POSTER P-71
Dyn-Biomol
Broadband Dielectric Spectroscopy on Molecular Behaviors
of Water Molecules in Blood Compatible Materials .
H. Saito*, R. Kita*, N. Shinyashiki*, S. Yagihara*, A. Mochizuki**
and M. Tanaka***
*Graduate School of Science and Technology, Tokai University, 4-1-1 Kitakaname,
Hiratsuka-shi, Kanagawa 259-1292, Japan.
**Department of Bio-Medical Engineering, School of Engineering, Tokai University.
***Institute for Materials Chemistry and Engineering. Kyushu University, 744 Motooka,
Nishi-ku, Fukuoka, 819-0395.
The thrombus is originally formed by biological defense. Blood proteins adsorb and
denature on the surface of blood compatible materials prepared the thrombus formation
model. Molecular behaviors of water should be important in the aggregation formation.
Recent studies on Differential Scanning Calorimetry (DSC) [1] and dielectric studies have
reported an existence of freezing bound water for hydrated poly(2-methoxyethyl acrylate)
(PMEA) and investigated relaxation phenomena due to side chain and segmental motions in
relatively lower frequency region [2]. In the present work, we performed broadband dielectric
spectroscopy (BDS) measurements for polymer and water molecules and compared those
dynamic behaviors in aqueous mixtures of PMEA and related polymer materials, such as
poly(2-hydroxyethyl methacrylate) (PHEMA) and poly(3-metxypropyl acrylate) (PMC3A) .
We prepared PMEA, PHEMA, and PMC3A with molecular weight distribution, Mw/Mn;
4.06, 2.51, and 2.5, respectively. BDS (Agilent Technologies 4294A(40Hz-110MHz),
N5230C(500MHz-50GHz), 86100C(10MHz-30GHz) ) was employed with open-end coaxial
electrodes with diameters, 2.2mm and 3.6 mm, which are terminated by polymer samples.
Comparing relaxation curves for polymer materials with the same water content, 9wt%, the
curves obtained in the GHz frequency region indicate more water in PMEA. On the other
hand, an increase in the relaxation time and a decrease in the distribution parameter β show
slow dynamics in the water structure. These inconsequent properties of molecular dynamics
of water in PMEA suggest that intermolecular interactions between water and polymers are
different, and more structured water should be closely related with the biocompatibility.
REFERENCES
1. Tanaka, M., Mochizuki, A., "Effect of water structure on blood compatibility—thermal analysis of water in
poly (meth) acrylate." Journal of Biomedical Materials Research Part A. 68, 684-695 (2004).
2. Hirata, T., et al. "Dynamics of a bioinert polymer in hydrated states by dielectric relaxation spectroscopy."
Physical Chemistry Chemical Physics. 19, 1389-1394 (2017).
P-72 POSTER
Dyn-Biomol
MD Simulation Studies of Protein Dynamics in Neutral
Confinement
Timothy Wohlfromm, Michael Vogel
Institut für Festkörperphysik, TU Darmstadt, Hochschulstr. 6, 64289 Darmstadt, Germany
We report on recent findings regarding dynamics of the elastin like protein model (VPGVG)50
and its surrounding hydration shell in a neutral pore.
Despite recent progress we lack understanding of dynamics of complex systems, such as
hydrated proteins, specifically when studied in confinement. To isolate direct effects of
confining geometries on protein-water couplings the pore consists of water molecules
restrained in position by harmonic potentials of varying restoring forces to simulate confining
surfaces with differing rigidity.
Varying the hydration level of the confined protein we find that the minimal degree of
hydration to observe bulk-like protein dynamics is 1g water / 1g protein.
As for water dynamics, we observe in spatially resolved analyses that with decreasing
distance to the pore wall the correlation times of water increase by more than one order of
magnitude. This effect is drastically reduced with reduced rigidity of the pore wall. In
addition the protein acts as a soft confinement to water in vicinity to its surface.
On the other hand, we find that the protein segments are more mobile at the surface than in
the center of the molecule. These results yield valuable insights into the interplay of protein
and water motions.
In addition, we systematically investigate changes in the dynamics of the elastin model when
water is replaced by other solvents such as glycerol.
POSTER P-73
Dyn-Biomol
Dielectric relaxation of PNIPAM-Urea Solution: interaction
and conformation
Cancan Zhang, Man Yang, Kongshuang Zhao
College of Chemistry, Beijing Normal University, Beijing, 100875, China
Up to now, the mechanism of the protein denaturation by urea has not been well
explained due to the complex structure of proteins. PNIPAM is often used as a model to study
the interaction of protein and urea[1]
becasue it contains functional group of peptide and can
experience similar behavior as protein, i.e., coil-to-globule transition with increased
temperature.
In this work, dielectric measurements were carried out for PNIPAM in urea aqueous
solution (0-7M) at 0.5-40 GHz as a function of temperature. An obvious relaxation is
observed near 10GHz. The temperature and concentration (urea) dependent dielectric
increment suggests that urea can reduce the LCST of PNIPAM. The fitting result of the HN
equation[2]
to the dielectric spectra shows that the relaxation is contributed from four sub-
relaxations: the side chain of PNIPAM (670~890ps), bound water (12.8~14.5ps), urea
(15.9~21.4ps) and the free water (6.2~8.7ps). The number of bound water (Zs-w) and urea (Zs-
u) obtained by the Cavell equation[3]
shows: (1) Zs-u keeps around 0.4, indicating that urea
molecules act as bridging agent linked to the adjacent side chains of PNIPAM by replacing
some of the originally bound water molecules. (2) Zs-w decreased linearly with the increased
of urea concentration within Curea<5M and kept a stable range within Curea>5M, implying that
both the enhanced hydrogen bond between water molecules by urea and the self-aggregation
of urea influence the phase transition of PNIPAM, and they reach balance at higher urea
concentration.
The above results predict that hydrogen bond interaction between urea and peptide
groups maybe a trigger that urea denatures the protein, which will open the entrance for water
and thus promote the protein unfolding.
REFERENCES
1. Pica, A.; Graziano, G.,. Phys Chem Chem Phys, 18, (21), 14426-33 (2016).
2. Havriliak, S.; Negami, S., Polymer, 8, 161-210 (1967).
3. Cavell, E.; Knight, P. C.; Sheikh, M. A., Transactions of the Faraday Society, 67, 2225-2233 (1971).
P-74 POSTER
Aging
Compressed Exponentials in Correlation Experiments: The
Influence of Temperature Gradients and Convection
Jan Gabriel, Thomas Blochowicz, Bernd Stühn
Technische Universität Darmstadt, Hochschulstr. 6-8, 64289 Darmstadt
In a wide range of correlation experiments, e.g., with laser light or partially coherent X-rays,
so called compressed exponential correlation functions were reported, i.e., c(t)∝exp[-(t/τ)β],
with β>1. This phenomenon is seen in soft matter systems like gels, microemulsions or foams
but also in the density correlation of ageing metallic glasses1
or in solutions of colloidal
particles in supercooled liquids2. While in many cases the source of this phenomenon can be
traced back to internal stresses in a sample out of equilibrium3, in some cases the reasons are
not well understood, like for example for colloidal particles in supercooled liquids close to Tg4
or for concentration fluctuations in binary glass formers5.
We performed multi speckle-dynamic laser light scattering experiments in a system of
polystyrene spheres in supercooled propanediol. At low temperatures compressed exponential
decays are observed in a multispeckle experiment, in agreement with literature findings in
similar systems. At the same time, due to the fact that in our setup the scattered light contains
near field contributions, clear indication for convection in the sample can be derived from the
speckle pattern, which is due to a slight temperature gradient across the sample cuvette
mounted in a cold finger cryostat. These effects increase with decreasing temperature and
after a temperature jump and in some cases can be corrected for by assuming convective flow
at constant velocity. Such corrections reduce or remove compressed exponential behavior in
our experiment [6]. Finally we compare different experimental setups and geometries with
respect to their sensitivity towards flow effects.
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POSTER P-75
Conf-TF
Thermal behavior of glycerol confined in pores
Junpei Kato1 , Yoshiharu Ito
2, Atsushi Nagoe
3 and Hiroki Fujimori
1
1Graduate School of Integrated Basic Sciences, Nihon University, 3-25-40 Sakurajosui,
Setagaya-ku, Tokyo 156-8550, Japan
2School of Materials and Chemical Technology Department of Materials Science and
Engineering, Tokyo Institute of Technology University,4259 Nagatsuta-cho, Midori-ku,
Yokohama, Kanagawa 226-8503, Japan
3Department of Mathematics and Science, School of Science and Engineering, Kokushikan
University, 4-28-1, Setagaya Setagaya-ku, Tokyo, 154-8515
A glassy state of liquid is generally a non-equilibrium state so that the molecule configuration
is frozen in a disordered state. The physical properties of the glassy state have been discussed
by various analytical methods. Adam-Gibbs theory, which is the one of them, shows that the
activation energy of molecules increases with increasing the cooperative rearranging region
(CRR) on relaxation process from the glassy state to the liquid state. The increasing of the
CRR causes that the number of neighboring molecules increases with decreasing temperature.
In this study, we used the typical glassy material, glycerol. The differential scanning
calorimetry (DSC) measurements of glycerol confined within mesoporous silica were
performed to discuss the thermal properties of the molecules in the mesoscopic region. As the
results, it was found that the glass transition temperature decreased with decreasing the pore
size. We will discuss the reasons based on the Adam-Gibbs theory.
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