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June 24 – 28, 2012

SIS2012 1

2 SIS2012

19th International Symposium on

SURFACTANTS IN SOLUTION

Program and Abstracts

June 24 – 28, 2012

Edmonton, Alberta, Canada

SIS2012 3

The content of this abstract book is based on abstracts submitted by the authors and presenters for the 19th International Symposium on Surfactants in Solution (SIS2012) through the conference website. Barring minor modifications with respect to style or corrected typographical errors, the abstracts are identical in content to what was submitted by the authors through the abstract submission system. The conference organizers are compiling this abstract book with the sole intention of distributing this among the conference participants. All rights, limitations, and liabilities pertaining to copyright remain solely with the authors of the abstracts. These abstracts are published with the implied understanding that the material submitted by the authors is original and do not infringe or violate any copyright. No part of this abstract book should be copied, or distributed without explicit written consent of the authors of the abstracts concerned, and/or the conference organizers.

Copyright © SIS2012

4 SIS2012

Welcoming Remarks

Greetings! Dear Symposium Participants: It is with great pleasure that we welcome you all to the 19th International Symposium on Surfactants in Solution (SIS 2012). The genesis of this series of symposia goes back to 1976 where the premier event in this series was held with the appellation "Micellization, Solubilization,. and Microemulsions." The highlight of the 1976 meeting was the illuminating presentation by Dr. Gilbert Spencer Hartley (a pioneer and a giant in the field of amphiphilic/amphipathic substances) titled "Micelles: Retrospects and Prospects", which was a real treat. Since 1976, this series of symposia have been held continuously on a biennial basis in many corners of the globe. The technical program of this meeting in Edmonton comprises four plenary lectures (by world-class scientists), approximately 135 oral presentations and 30 posters. Both fundamental and applied aspects of surfactants will be covered in this meeting. The applications of surfactants (known humorously as molecules with schizophrenic characteristic) range from mundane (e.g., washing clothes) to biomedical to energy conversion to nanotechnology - and all these topics will be discussed in this symposium. These days, the paradigm is "Think Green, Go Green", and lately there has been a brisk research activity in coming up with green surfactants. Naturally, this will be reflected in the symposium this year. The presenters in this conference hail from many countries, and thus, the meeting is veritably international in scope and spirit. We very much appreciate the presenters sharing their latest research findings. Edmonton and its vicinity offer diverse recreational activities and sight-seeing, and we strongly encourage you to take advantage of what Edmonton has to offer. Anything we can do to make your stay in Edmonton more enjoyable, let us know. We thank our sponsors, Suncor Energy, Kemira, and Elsevier for their support of this conference. We are also grateful to our volunteers and session organizers for putting together this program. We are thrilled that the University of Alberta has this opportunity to be your host while you are in Edmonton. We sincerely hope you will find this meeting scientifically stimulating and rewarding, and overall an enjoyable and memorable experience. Sincerely The Organizers Kash Mittal, Alidad Amirfazli and Subir Bhattacharjee

SIS2012 5

Contents:

Acknowledgment 6

Program Overview 7

Symposia and Sessions 9

Oral Presentations 10

Poster Presentations 20

Plenary Lectures 24

Abstracts 34

List of Authors 142

6 SIS2012

Acknowledgment

The Organizing Committee is grateful to the sponsors and supporters of the 19th International Symposium on Surfactants in Solution (SIS2012).

Support from the following organizations is gratefully acknowledged:

Platinum Sponsors:

Gold Sponsor:

Department of Mechanical Engineering, Faculty of Engineering, University of Alberta.

Silver Sponsor:

Elsevier

SIS2012 7

Program Overview

Sunday June 24, 2012

Venue: Solarium (Engineering Teaching and Learning Centre, ETLC)

17:00 Registration Opens

18:30 Welcoming Reception/Mixer

Monday June 25, 2012

Start End Venue Event

8:00 - ETLC Solarium Registration opens

8:15 8:25 Inauguration

8:25 8:35 Kash Mittal Award Announcement

8:35 9:35 Kash Mittal Award Lecture ETLC 1-001

9:35 9:50 Coffee Break

9:50 12:00 NREF Morning Parallel Sessions

Adsorption at Interfaces (ADS) NRE 2-001

Symposium on Energy & Environment (ENER) NRE 2-003

Interfacial Tension and Capillarity (INTT) NRE 2 -127

12:00 13:30 Lunch Break

13:30 15:00 NREF Post Lunch Parallel Sessions





15:30 17:30 NREF Afternoon Parallel Sessions




17:30 18:30

18:30 20:30 Solarium, ETLC Poster Session

Tuesday, June 26, 2012



8:30 9:30 Plenary Lecture 1, ETLC 1-001



Surfactants in Tribology (TRIB) NRE 2-001


Surfactants and Self Assembly (SURF) NRE 2-127



8 SIS2012


Thermodynamics and Kinetics (THERMO) NRE 2-003

Surfactants and Self Assembly (SURF) NRE 2-127



Thermodynamics and Kinetics (THERMO) NRE 2-003

17:30 21:00 Fairmont Hotel Macdonald

Banquet

Wednesday, June 27, 2012







Micelles and Emulsions (MIC) NRE 2-003

Surfactants and Polymers in Biosystems (BIOSURF) NRE 2-127



Wetting Spreading and Superhydrophobicity (WETT) NRE 2-001


Surfactants and Polymers in Biosystems (BIOSURF) NRE 2-127



Wetting Spreading and Superhydrophobicity (WETT) NRE 2-001


Interfacial and Surface Forces (INTF) NRE 2-127

Thursday, June 28, 2012




9:50 12:00 NREF Morning Sessions

Interfacial and Surface Forces (INTF) NRE 2-127

Monolayer and Langmuir Films (MONO) NRE 2-003

12:00 13:30 Conference Ends

SIS2012 9

Symposia and Sessions

• Adsorption at Interfaces (ADS) • Special Symposium on Energy and Environmental Applications (ENER) • Interfacial Tension and Capillarity (INTT) • Surfactants in Tribology (TRIB) • Wetting, Spreading, and Superhydrophobicity (WETT) • Surfactants and Self-Assembly (SURF) • Surfactants and Polymers in Biosystems (BIOSURF) • Interfacial and Surface Forces (INTF) • Micelles and Emulsions (MIC) • Thermodynamics and Kinetics in Surfactant and Colloidal Systems (THERMO) • Monolayer and Langmuir Films (MONO) • Posters

http://www.sis2012.ualberta.ca/wp-content/uploads/2012/06/Adsorption_at_Interfaces_ADS.htm

http://www.sis2012.ualberta.ca/wp-content/uploads/2012/06/Special_Symposium_on_Energy_Env_ENER.htm

http://www.sis2012.ualberta.ca/wp-content/uploads/2012/06/Interfacial_Tension_Capillarity_Surface_Forces_INTT.htm

http://www.sis2012.ualberta.ca/wp-content/uploads/2012/06/Surfactants_in_Tribology_TRIB.htm

http://www.sis2012.ualberta.ca/wp-content/uploads/2012/06/Wetting-Spread.-Sup-WETT.htm

http://www.sis2012.ualberta.ca/wp-content/uploads/2012/06/Surfactants_and_Self-Assembly_SURF.htm

http://www.sis2012.ualberta.ca/wp-content/uploads/2012/06/Surfactants_Polymers_Biosystems_BIOSURF.htm

http://www.sis2012.ualberta.ca/wp-content/uploads/2012/06/Interfacial_and_Surface_Forces_INTF.htm

http://www.sis2012.ualberta.ca/wp-content/uploads/2012/06/Micelles_and_Emulsions_MIC.htm

http://www.sis2012.ualberta.ca/wp-content/uploads/2012/06/Thermodynamics_and_Kinetics_THERMO.htm

http://www.sis2012.ualberta.ca/wp-content/uploads/2012/06/Monolayers_and_Langmuir_Films_MONO.htm

10 SIS2012

Oral Presentations

SIS2012 11

Submission ID Title Contact Author Topics

3 Role of Self-Organizing Systems on Various Organic Reactions

Birendra Kumar INTF

4 Mixed micellization and interfacial behaviors of two novel cationic gemini surfactants and cationic, anionic and nonionic conventional surfactants

Nabel Negm INTF

5 Environmentally friendly surface active agents and their potential in Petroleum industry

Nabel Negm TRIB

6 Molecular Dynamic Study of a lubricant system by NMR spectroscopic techniques.

A. S SARPAL TRIB

8 Flow of Concentrated Pickering Emulsions in Narrow Gaps

Catherine Whitby MIC

10 Particle-laden fluid interfaces: Structure, dynamics and microrheology

Ramon Rubio INTT

11 Evaporation of super-spreader solution droplets: Effects of concentration, temperature and relative humidity

Hezekiah Agogo WET

14 Surfactant Tasks in Enhanced Oil Recovery Processes: Oil Displacement, Wettability Alteration, Foam Stability

Clarence Miller ENER

18 Oligofructose fatty acid esters create air/water interfaces with extremely high moduli

Silvia van Kempen INTT

19 On the thermodynamics and kinetics of cyclodextrin-bolaform surfactant host-guest compounds

Artur Valente THERMO

20 SURFACTANT ADDITIVES USED AS FRICTION AND WEAR REDUCERS FOR WATER-BASED DRILLING FLUIDS

José González TRIB

22 pH-dependent polyampholyte SDS interactions in highly diluted aqueous solutions and in reverse microemulsion droplets

Joachim Koetz MIC

24 Lubrication of brass surfaces with fatty acids: from film formation to friction

Juliette Cayer-Barrioz

TRIB

26 Adsorption mechanisms of surfactant mixtures on non-polar solid surfaces and importance for the stability of dispersions

Wolfgang von Rybinski

ADS

27 Tribological properties of aqueous solutions as result of breach of equilibrium double electric layer

Natalia Kochurova THERMO

28 The role of substrate electrical charge on the drying of colloidal suspensions

Miguel A. Rodríguez-Valverde

WET

29 Cleavable Cationic Gemini Surfactants Ali Reza Tehrani Bagha

SURF

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33 Natural surfactant for solubilizing Crude oil Eshu Middha ENER

34 Experimental Study on the Interactions between Polyvinylpyrrolidone and Cationic Gemini /Conventional Surfactants

M Kamil BIOSURF

35 Triton-X100 transfer across the water/dodecane interface: dynamic interfacial tension behavior change with the transfer pathway

Pierre-Marie Gassin INTF

37 Marangoni Driven Spreading on Model Airway Surface Liquid Subphases

S. Garoff BIOSURF

38 Autophobing on Liquid Subphases by Surface Transport S. Garoff WET

39 Tribological properties of inoc liquids for hard coatings Shinya SASAKI TRIB

40 Nano-Friction of Silica Surfaces in Solutions of Various Electrolytes and pH’s

Ko Higashitani TRIB

41 Cationic Polymer Surfactant as a self-healing boundary lubrication film on silicon oxide surface

Seong H. Kim TRIB

42 Effect of Lateral Roughness on the Adsorption of Surfactants

Brian Grady ADS

43 Softness effect on the wetting behavior of pillar-like patterned PDMS surfaces

Li-Jen Chen WET

44 Van der Waals interactions and the solubilisation of oil in microemulsions

Americo Boza Troncoso

INTT

46 Spreading of volatile droplets containing non-ionic polyoxyethylene alkyl ether (CnEOm) surfactants. Correlative relationships between spreading parameters and properties of surfactants and surfaces

Victoria Dutschk WET

47 Mixed aggregate formation in gemini surfactant / 1,2-dialkyl-sn-glycero-3-phosphoethanolamine systems: Implications for DNA transfection

Shawn Wettig BIOSURF

48 pH-responsive self-aggregates of amphiphilic graft copolymers

Jong-Duk Kim INTF

49 Electrokinetic curves normalized to the concentration of surfactant per unit of surface area

Marek Kosmulski ADS

50 Tribological Surface Chemistry of Model Lubricant Additive Measured in Ultrahigh Vacuum

Wilfred Tysoe TRIB

51 Computer simulation of self-assembly of linear and facial surfactant molecules with multiple hydrophilic groups

Hans-Jörg Mögel SURF

SIS2012 13

52 Effect of different oil loadings on oil-particle-water separation in a falling sphere configuration

Sasan Mehrabian ENER

53 Seeing Surfactant-stabilized Microbubbles by Freeze-fracture Electron Microscopy

Brigitte Papahadjopoulos-Sternberg

BIOSURF

54 Morphological evolution of depinning drops Ciro Semprebon WET

55 Development of a method to probe the surface activity of flavor compounds

Amanda Schober ADS

56 Spontaneous Emulsification and Phase Diagrams: Contact between Water and Selected Compositions in the System of Water, Benzene and Ethanol

Stig E. Friberg MIC

57 Preparation and Stability of a Triple Janus Emulsion Stig E. Friberg MIC

58 Study of sorption behavior of phenol in DODAC vesicular dispersions by means of 1H and PFG-NMR techniques

Paolo Sabatino MIC

60 Marangoni trap at a smart liquid surface Subramanyan Namboodiri Varanakkottu

INTT

61 Biobased oil structure on amphiphilic and tribological properties

Girma Biresaw TRIB

62 Capillary pressure and contact line force on a soft solid Jacco Snoeijer WET

63 Heat induced gel and thermo-coloring phenomena in emulsions of an amidoamine derivative

Takeshi Kawai MIC

64 Tribological Behavior of Polyelectrolyte Brushes with Various Ionic Side Chains in Aqueous Environment

Atsushi Takahara TRIB

65 Interaction of two coumarin derivatives within the self-assemblies of surfactants- A steady state and time resolved fluorescence study

Aijaz Ahmad Dar SURF

67 PalmitateLuciferin: A Molecular Design for the Second Harmonic Generation Study of Ion Complexation at the Air-Water Interface

Gaelle Martin-Gassin MONO

68 Influence of dodecane solubilisation on dynamic surface tension and dilational rheology of Triton X-45 micellar solutions

Reinhard Miller INTT

69 Effect of water hardness on surface tension and dilational visco-elasticity of sodium dodecyl sulphate solutions

Reinhard Miller INTF

70 Trends in biolubricant development Girma Biresaw BIOSURF

14 SIS2012

71 Analytical and CFD Modeling of Drop Imbibition into an Axisymmetric Capillary

Markus Bussmann INTT

72 Improving performance of the formulation of surfactant-oil-water systems to attain ultralow tension and high solubilization in enhanced oil recovery and other applications: A review of current understanding and prospective future.

Jean-Louis Salager ENER

74 Mn3O4 Nanorods on Graphene Sheets for High-Power and High-Energy Density Supercapacitor Electrodes

Jong-Duk Kim INTF

75 Qualitative and quantitative analysis of CnTAB adsorption layers at the water-oil interface

Nenad Mucic ADS

78 Monitoring of waters pollution by measurements the bubble velocity variations

Jan Zawala ADS

79 Formation of a novel, phase-separated Langmuir film in a binary phospholipid-perfluorinated fatty acid surfactant mixture

Matthew Paige MONO

80 Controlling adhesion and friction using structured amphiphilic polymer layers: role of conformation and degree of ionization

Suzanne Giasson TRIB

81 Response of Microbubbles to Gas Exchange James Kwan INTT

82 Effect of Molecular Structure of Self-Assembled Monolayers on Their Tribological Properties

Miki Nakano TRIB

83 Impact of Mixing on Demulsifier Performance in Oil Sands Froth Treatment

Suzanne Kresta ENER

84 Physico-chemical Properties of Gemini Surfactants Containing Ester Bonds

Kabir ud-Din MIC

85 Soft Vesicles in the Synthesis of Hard Materials Jingcheng Hao SURF

86 Effects of Palmitic Acid - Silica Nanoparticle Complexes on Liquid Interfaces

Libero Liggieri ADS

89 Settling Properties of Aggregates in Paraffinic Bitumen Froth Treatment

Jan Zawala ENER

91 Interactions of hyaluronan with surfactants measured by HR-US

Andrea Kargerova SURF

92 Development of a new subphase multi-exchange pendant drop tensiometer for in-vitro digestion studies

Miguel Angel Cabrerizo-Vilchez

ADS

93 Effect of Salinity on Interfacial Tension of Model and Crude Oil Systems

Harvey Yarranton ENER

SIS2012 15

95 Hydrophobic Interactions between Polymer Surfaces: Using Polystyrene as a Model System

Ali Faghihnejad INTF

96 Microemulsion systems with non-ionic surfactants for the solubilization of petroleum waste

Tereza Neuma Dantas

ENER

98 Physicochemical investigation of mixed reverse micellar systems in biocompatible oils: II. Microstructure by conductance and DLS studies

Kaushik Kundu MIC

99 Effects of Secondary Structures on Adsorption Behavior of Peptides

Larry Unsworth ADS

101 Synergistic interactions between macromolecules and surfaces provide enhanced lubrication and wear protection

xavier banquy TRIB

103 Surfactant based self-assembled coatings to minimize protein adsorption at solid/liquid interface

Mahmoud F. Bahnasy

BIOSURF

105 Probing Interfacial Properties and Surface Forces of Comb-type Polymer Polystyrene-graft-Polyethylene oxide (PS-g-PEO) using a Surface Forces Apparatus

Hongbo Zeng INTF

106 Effect of surfactant chain length on the interfacial properties of polyallylamine hydrochloride/ sodium alkylsulphate mixtures at the water/hexane interface

Saule Aidarova ADS

108 INFLUENCE OF ADDITIVES IN THE PROPERTIES OF A MICROEMULSION SYSTEM AND ITS APPLICATION IN ENHANCED OIL RECOVERY

Afonso Dantas Neto MIC

109 Concentric drops studies for a quantitative analysis of stabilizing effects of emulsifiers in multiple emulsions

Juergen Kraegel ADS

111 O/W suspo-emulsions containing technical surfactants as models of industrial oily wastewater

Simona Schwarz MIC

113 New microemulsion cleaners as replacement for solvents

Jürgen Allgaier ENER

116 Dilational Rheology, Structure and Phase Behavior of Mixed Lipid-Nanoparticle Monolayers

Francesca Ravera ADS

117 Separable Chelating Agents Håkan Edlund SURF

119 Effect of the frother overdosage on kinetics of the three-phase contact formation at hydrophobic surfaces

Jan Zawala INTT

121 Properties of interfacial layers formed by gelatin-polysaccharide complexes

Svetlana Derkach INTT

122 Understanding Structures of Athabasca Bitumen at air/water interfaces by Brewster Angle Microscopy (BAM) of Langmuir films

Chandra W. Angle MONO

16 SIS2012

123 From superhydrophobic to superamphiphobic coatings Doris Vollmer WET

125 Effect of phase separation on the properties of lipid monolayers

Svetlana Baoukina BIOSURF

127 Role of asphaltenes in stabilizing W/O emulsions – thin liquid film study

Plamen Tchoukov ENER

128 Effect of thermal substrate conductivity on the evaporation mode of droplets of colloidal suspensions

Vahid Bazargan INTF

129 Xanthation modified polyacrylamide in sulfide mineral flotation and its mechanism investigation

Lei Wang SURF

130 Mixing Characterization and Scale-up of Additive Performance: Comparison of a Bench Scale Stirred Tank with the Shear and Sedimentation Test Cell (SSTC)

Suzanne Kresta THERMO

131 Modeling Contact Angles of Surfactant Solutions on Smooth and Rough Heterogeneous Surfaces

Alidad Amirfazli WET

132 Dilational Interfacial Rheology for Increasingly Deasphalted Bitumens and n-C5 Asphaltenes in Toluene/NaHCO3 solution

Chandra W. Angle ENER

133 Characterization of Biocompatible Polymerized Diyne PC Surfactant

Charles Lucy BIOSURF

134 The velocity field near the moving contact line in an evaporating drop

Prashant Rakhmaji Waghmare

INTF

135 Chemical Trapping in Surfactants with Amino Acid Headgroups. Developing Protocols for Chemical Determination of Protein Topologies at Membrane Interfaces

Laurence Romsted MIC

136 Study of dynamic interfacial tension of sodium octyl benzenesulfonate at the water/hexane interface

Juan Pereira INTT

137 Thermodynamics Insight into Surfactant Supported Ultrafiltration of Wastewater

Sakhawat Shah THERMO

138 The Rheology of Water-in-Oil Emulsions and the Relationship to Emulsion Stability

Merv Fingas ENER

140 Surface rheology of layers at the surface of water Dominique Langevin MONO

142 STUDY OF THE PROPERTIES OF FOAM OF SODIUM OCTYL BENZENESULFONATE, SODIUM DECYL BENZENESULFONATE AND SODIUM DODECYLSULFATE

Victor Coronel ADS

SIS2012 17

143 Harnessing Kinetics to Estimate Antioxidant Distributions in Emulsions Composed of Cationic and Anionic Surfactants and Demonstrate a Surprisingly Modest Sensitivity of Observed Rate Constants on Emulsion Droplet Size from Nano to Micro.

Laurence Romsted THERMO

144 ROLE OF SURFACTANTS IN WATER-PROOFING OF BUILDINGS, MAKING BETTER ROADS, REDUCING WATER LOSS FROM SOIL AND ENHANCING PLANT GROWTH

Dinesh O. Shah ENER

145 Sensitivity Enhancement of Quenchofluorimetric Methods for the Determination of Selected Analytes via Micellar Amplification

Aamna Balouch MONO

146 Is kinetics of micelles related to miceller catalysis? Manish Mishra THERMO

147 Phase Characteristics of Langmuir Monolayers Dieter Vollhardt MONO

149 Superhydrophobic surfaces with multiscale roughness made from raspberry particles

Lena Mammen WET

152 Controlling emulsion stability by using charged silica nano-particles

Juan López SURF

154 Reverse Ostwald Ripening: A mass transfer mechanism which can be present during the first few minutes of foams life.

Juan López ADS

156 Salt-free catanionic surfactants in water: role of chain-length mismatch on multifaceted aggregation behavior

Eduardo Marques SURF

158 Molecular behavior of lubricants/additives under lubricating condition

Koji Miyake TRIB

159 Pseudo-dewetting Driven Pillar Formation from Drying Polymer Droplets

Kyle Baldwin WET

160 Self Assembled Monolayers: Fundamental Aspects and Applications to M/NEMS Technology

Roya Maboudian TRIB

162 The Theory of Brownian Coagulation Lee R. White THERMO

163 Synergism in Spreading of Hydrocarbon-Chain Surfactants on Highly Hydrophobic Surfaces

Yongfu Wu WET

165 Time scales of spontanoues spreading of drops on soft viscoelastic surfaces

Elmar Bonaccurso WET

166 Overview of SAGD Water Treatment Processes David Pernitsky ENER

167 Thermodynamics of Microdrop Concentrating Processes

Janet Elliott THERMO

168 Probing Structure-Nanoaggregation Relations of Polyaromatic Surfactants in the Bulk Phase and at the Oil/Water Interface: A Molecular Dynamics Simulation

Subir Bhattacharjee ENER

18 SIS2012

169 AC Electric Actuation of Hydrogels Employing Dielectric Coated Electrodes

Joseph Ryan Saunders

BIOSURF

170 Interfacial characteristics and role of a biodegradable ethylcellulose in demulsification of water in heavy oil emulsions

Zhenghe Xu ENER

171 Surfactants for size Selective Synthesis of Metal Nanoparticles (NPs)

Tarasankar Pal MIC

172 Immobilized Surfactant on Solids for environmental remediation

Anjali Pal MIC

173 Polymers in Action: Nontraditional Waste Water Treatment Methods in Oilfield Applications

Amir Mahmoudkhani

ENER

174 Advanced Oxidation Processes in Water Treatment Kaj Jansson ENER

175 Chemical additives: Future opportunities for bitumen exploitation

Uriel Guerrero ENER

SIS2012 19

20 SIS2012

Poster Presentations

SIS2012 21

Poster No. Submission ID

Title Contact Author Full Name

2 13 Use of continuous oil phase microemulsions in the formulation of completion fluids

Vanessa González

3 21 INVESTIGATION OF THE SOLUBILITY AND INTERFACIAL BEHAVIOR OF VARIOUS ASPHALTENES UNDER SEVERE REFINERY AND TRANSPORT CONDITIONS

Guangzhe Yu

4 25 Thermosensitivity of superhydrophobic surfactants polymeric complexes

Kuralay Korzhynbayeva

5 30 Cationic ester-containing gemini surfactants: Chemical hydrolysis and biodegradation

Ali Reza Tehrani Bagha

6 31 Cationic Ester-Containing Gemini Surfactants: Adsorption at Tailor-Made Surfaces Monitored by SPR and QCM


7 32 Stable and Ester-Containing Cationic Gemini Surfactants: Shape, Size and Solubilization of Micelles


8 59 Determination of the enclosed volume of DODAC vesicular dispersions by means of NMR diffusometry and T2 relaxometry

Paolo Sabatino

9 66 Preparation and Application of Biocompatible Niosomes Containing β-sitosterols

Asami Aoki

10 73 Emulsifying, transporting and breaking heavy crude emulsions : A review of recent understanding and prospective future.

Jean-Louis Salager

11 87 GROWTH OF GOLD NANOPARTICLES USING CATIONIC GEMINI SURFACTANTS: EFFECTS OF STRUCTURE VARIATIONS IN HEAD AND TAIL GROUPS


12 90 Comparison between a Monomeric and Gemini Cationic Surfactant for Corrosion Protection of Mild Steel in Sulfamic Acid

Mohammad Mahdavian

13 94 Washing diesel contaminated soils with microemulsion-precursor solutions for the removal of aromatics

Tereza Neuma Dantas

22 SIS2012

14 97 Chromium extraction from tannery sludge by Winsor II and Winsor III microemulsion systems

Afonso Dantas Neto

15 100 Enhanced Gene Delivery through Gemini Surfactant Mediated Transfection of Linear Covalently Closed (lcc) Mini-Plasmids

Chi Hong Sum

16 102 Folate-linked light-sensitive liposome incorporating 7-acetoxycoumarin responding to UV-irradiation for cancer therapy

Hee Jin Seo

17 104 The surface tension of polyvinyl alcohol and Triton X-100 mixtures

Saule Aidarova

18 110 Mixed Protein-Surfactant Adsorption Layers Formed in a Sequential and Simultaneous Way at the Water/Air and Water/Oil Interfaces

Juergen Kraegel

19 112 Sticky removal from wastewater, characterized by dynamic surface measurements

Simona Schwarz

20 115 The investigation of liquid films by the LIFT Tensiometer

Libero Liggieri

21 118 Atomic Force Microscopy studies on Langmuir-Blodgett Films of Lipids-Nanoparticles Mixed Systems

Francesca Ravera

22 120 Surfactant solutions and dispersed systems at superhydrophobic surfaces in air and liquid environment

Libero Liggieri

23 124 Phase behaviour of microemulsions with weak and strong surfactants

Doris Vollmer

24 126 Study of interactions in aqueous solutions between a surfactant nonionic and added electrolyte: Effect on cloud point.

LISBETH GIESURIN

25 141 Microemulsion Flow in Porous Medium for Enhanced Oil Recovery

Vanessa Santanna

26 150 Transparent silica nano- and microchannels for microfluidic devices

Lena Mammen

27 151 The Influence of molecular interactions on foaming properties from surfactant systems

Gabriela Camacaro

28 153 FORMULATION OF SURFACTANT-OIL-WATER (SOW) SYSTEMS FOR THE REMOVAL OF PETROLEUM CONTAMINATED SOILS. EFFECT OF DIFFERENT ALCOHOLS.

Ana Garcia

SIS2012 23

29 155 Wettability evaluation of reservoir rocks under ASP injection from different techniques: Amott-Harvey, RMN y XPS.

Daniela Rodríguez

30 157 Fixing of gathering dust surface of the Aral Sea by interpolymer complexes of polyethylenimine

Saule Aidarova

1 7 Structure of Concentrated Oil-in-Water Pickering Emulsions

Catherine Whitby

24 SIS2012

Plenary Lectures

SIS2012 25

The Kash Mittal Award Lecture

Monday June 25, 8:35 am – 9:35 am

Dr. Dominique Langevin

Laboratoire de Physique des Solides,

CNRS, Université Paris Sud, France.

Dominique Langevin started research in 1967, in the Physics Laboratory of the Ecole Normale Supérieure (ENS) in Paris and joined CNRS in 1969. Her thesis was on light scattering by liquid surfaces (pure liquids, liquid crystals, monolayers). She worked one year in the laboratory of Pierre Gilles de Gennes at the College de France, studying the transport of nanoparticles in semi-dilute polymer solutions. Returning to ENS in 1977, she started work in the microemulsion area, and, at the end of the 80’s, refocused on other topics, new phases of surfactants (wormlike micelles, swollen lamellar phases), emulsions and foams. Between 1994 and 1998, she was director of the Centre de Recherche Paul Pascal in Bordeaux. She joined afterwards the Solid State Physics Laboratory in Orsay. She now works on various topics: mixed solutions of polyelectrolytes and surfactants of opposite signs, foam films, foam drainage, Ostwald ripening in emulsions and foams, crude oil emulsions. One of her newest activities in the toxicity of nanoparticles, carbon nanotubes in particular.

Dominique Langevin published about 300 papers, edited two books. She received various awards, including the silver medal of CNRS in 2002 and the L’Oreal Unesco award for Women in Science in 2005.

26 SIS2012

Properties of surfactant monolayers and their relation to

microemulsions, emulsions and foams properties

Dr. Dominique Langevin

Laboratoire de Physique des Solides,

CNRS, Université Paris Sud, France.

Surfactants form monolayers at the air-water and oil-water interface, which can be

characterized by a number of properties : surface tension, static and dynamic, surface

curvature elasticity, surface compression and surface shear elasticities and viscosities. We

will show how the knowledge of these properties allows predicting the behavior of

oil/water or air/water dispersions. For instance, for microemulsions that are

thermodynamically stable dispersions, one can predict dispersion type and size, as well as

interfacial tensions between microemulsions, oil and water. For emulsions and foams that

are thermodynamically unstable dispersions, the prediction of dispersion type and size is

more difficult and will be discussed. Surfactant layer properties also control the

destabilization processes : gravity effects (creaming, sedimentation, drainage), Ostwald

ripening and coalescence of drops or bubbles (although in this case experimental

evidence is still scarce).

SIS2012 27

PLENARY LECTURE

PL-1

Dr. Reinhard Miller Max Planck Institute of Colloids and Interfaces

Golm, Germany

Dr. Reinhard Miller is group leader at the Max Planck Institute of Colloids and Interfaces in Potsdam, Germany. He studied Mathematics in Rostock and Colloid Chemistry in Dresden. His scientific interests are focused on dynamics of interfacial layers containing proteins, surfactants and other food relevant compounds. Dr. Miller edited the book series Studies in Interface Science (24 volumes) and is now editor of the Progress in Colloid Interface Science series. He published about 400 papers in refereed journals. Since September 2011, he is President of the European Colloid and Interface Society.

28 SIS2012

Single Drop/Bubble Experiments to Study the Dynamics of Liquid

Interfaces

– From Bubble Pressure Tensiometry to Direct Drop/Bubble

Interactions

A. Javadi1, N. Mucic

1, J.Y. Won

1, M. Karbaschi

1,7, B. Reetz

1, M. Born

1, J. Krägel

1,

A.V. Makievski2, N.M. Kovalchuk

1,3, V.I. Kovalchuk

3, G. Loglio

4, P. Pandolfini

4,

Liggieri5,

F. Ravera5, V.D. Mys

6, V.B. Fainerman

6 and R. Miller

1

1 MPI Colloids and Interfaces, Potsdam, Germany; 2 Sinterface Technologies, Berlin, Germany;

3 Institute of Bio-Colloid Chemistry, Kiev, Ukraine; 4 University of Florence, Sesto Fiorentino,

Italy;

5 CNR - Istituto per la Energetica e le Interfasi, Genoa, Italy;

6 Donetsk Medical University, Donetsk, Ukraine; 7 Sharif University, Teheran, Iran

The dynamics of liquid interfaces is of eminent importance for many modern

technologies. The production and storage of foam and emulsion products is a prominent

example where liquid interfaces are for example freshly formed and expanded (foaming,

emulsification) or compressed (coalescence, Ostwald ripening). A quantitative

knowledge of the dynamics of liquid interfacial layers provides an excellent starting point

for tailoring formulations for the optimization of technologies. Various experimental

techniques combined with quantitative theoretical models represent an efficient toolbox

to meet the requirements in practice.

The Maximum Bubble Pressure Tensiometry (MBPT), known for more than 150 years,

has been developed mainly during the last 20 years as method for dynamic surface

tensions of surfactant solutions and can be called now the World Champion in terms of

shortest adsorption times. MBPT allows getting experimental data down to 100 µs and in

this way gives insight into the fast formation of adsorption layers especially for

concentrated solutions. Beyond the CMC of a surfactant the experimental data even allow

analyzing the mechanism of micelle formation and dissolution kinetics.

Tensiometry methods based on the profile of drops and bubbles (PAT) are at present the

work horses in all interfacial laboratories. Its triumphal march was founded mainly by the

availability of electronic video cameras and frame grabbers, used via computers. While in

the beginning, powerful workstations were needed to cope with the huge amount of data,

nowadays even laptops equipped with a webcam are suitable for practicing this

methodology. Fully automatic instruments exist on the market which give access to

various types of investigations, not only of the adsorption of surfactants at a drop or

bubble surfaces of fixed surface area. Computer controlled dosing systems provide

additional protocols, such as generation of transient or harmonic perturbations, or even

real time drop volume exchange to study the adsorption of different surface active

compounds in a sequential way.

A quick and successful career can be observed presently for capillary pressure techniques.

Being the analogue of the MBPT for interfaces between two immiscible liquids, they

represent methods which are unique for many experimental conditions, such as studies at

SIS2012 29

interfaces between two liquids of similar density or even liquid interfaces under

microgravity.

Most recently microfluidics became very modern. Most of these tools allow to visualize

interesting phenomena like drop formation or fusions etc., but very often for systems

which have been tailored for respective targets by setting viscosities and densities. A

more efficient trend is to equip such tools with elements to directly measure the key

quantities, for example the dynamics of the interfaces involved in the observed processes.

With such set-ups combined with a fast video technique experimental protocols become

realistic about which we did not even dream 25 years ago.

Finally, great progress has been made in different theoretical simulations, such as

molecular dynamics (MD) and computational fluid dynamics (CFD). With such a

theoretical background highly dynamic processes become quantitatively understood. MD

and CFD simulation studies combined with modern experimental tools can lead to a

completely new scientific level of understanding dynamic liquid interfaces.

30 SIS2012

PLENARY LECTURE

PL-2

Dr. Theodorus G.M. van de Ven Centre for self-assembled chemical structures,

Department of Chemistry, McGill University, Montreal, QC, Canada.

Professor Theo van de Ven is an expert in colloid and surface chemistry, both in fundamental aspects and applied to papermaking and cellulosic materials. He has published well over 330 papers in the scientific literature, among which a book (“Colloidal Hydrodynamics”, Acad. Press 1989) and several book chapters. Presently Prof Theo van de Ven holds a Senior NSERC/FPInnovations Industrial Research Chair in “Colloid and Papermaking Chemistry”. He is the Scientific Director of a Strategic NSERC Research Network in “Innovative Green Wood Fiber Products”. Moreover he is the Director of a FQRNT Centre for Self-Assembled Chemical Structures (CSACS) and the Director of the Pulp and Paper Research Centre at McGill. His major awards are: Elected as a Fellow of the Royal Society of Canada (1998) American Chemical Society (ACS) Award in Colloid and Surface Chemistry (1996).

SIS2012 31

Self-assembly of alternating copolymers and block copolymers into nanotubes and nanorods

Prof. Theo van de Ven

Centre for self-assembled chemical structures, Department of Chemistry, McGill University, Montreal

Abstract

Alternating copolymers of poly(styrene alt. maleic anhydride) (SMA) are found to self assemble in water into nanotubes, with a diameter of about 4 nm at neutral pH, when an internal hydrogen bond is formed between the protonated and dissociated carboxyl groups of the hydrolized maleic acid. This association is driven by π-stacking of the phenyl groups in styrene. This self-assembly reflects itself among others in a slow attainment of the surface tension of SMA solutions at neutral pH, which is absent at high and low pH. For SMA many chiral sequences result in self-assembly, an effect also predicted by molecular modeling. For an imide derivative of SMA (SMI), only isotactic molecules self-assemble, resulting in very low yields. Nanotube formation is also predicted in some alternating oligopeptides. Nanostructures can also be formed by block copolymers. We have studied biocompatible block copolymers of poly(caprolacton) and poly(ethylene oxide), which are found to form spherical micelles, which slowly convert into nanorods. The reasons for this will be discussed.

32 SIS2012

PLENARY LECTURE

PL-3

Dr. Clarence A. Miller Rice University, Houston, TX, USA.

Clarence A. Miller received BA and BS degrees from Rice University in 1961 and a PhD degree from the University of Minnesota in 1969, all in chemical engineering. From 1961-1965 he was a Naval officer serving in the headquarters of the Naval Nuclear Power Program in Washington D.C. He began his academic career in 1969 in the chemical engineering department of Carnegie-Mellon University, moving to Rice in 1981. He served six years as chair of Rice’s chemical engineering department and held the Louis Calder chair from 1994 until his retirement from academic duties in 2008. At that time he was appointed a part-time Research Professor and has continued to conduct research, primarily on surfactant processes for enhanced oil recovery and on emulsions. During his career his research has dealt with interfacial phenomena, especially those involving surfactants such as emulsions, microemulsions and foams with applications to detergency, enhanced oil recovery, and remediation of ground water aquifers.

SIS2012 33

EFFECTS OF PHASE BEHAVIOR, SOLIDS, AND MASS TRANSFER

ON EMULSION FORMATION AND DESTABILIZATION

Clarence A. Miller

Department of Chemical and Biomolecular Engineering

Rice University, Houston, TX, USA.

Equilibrium phase behavior of oil-water-surfactant systems can affect both formation and

breaking of emulsions. A recent study showing how microemulsion phase behavior

controls spontaneous formation of nanoemulsions is described including data on drop

growth rates for various conditions. In the absence of rigid films at the drop interfaces,

emulsions are least stable for phase behavior in the Winsor III region where a

bicontinuous microemulsion coexists with excess oil and brine phases. Researchers on

food emulsions have in recent years proposed an “orogenic” model by which rigid films

can be removed by suitable surfactants, allowing separation to occur if phase behavior is

suitable as indicated above. Some general comments are made on solid-stabilized

emulsions, followed by discussion of how an emulsion can be destabilized by changing

the wettability of fine solid particles at the drop interfaces.

34 SIS2012

Abstracts of Presentations

SIS2012 35

3 ,

Role of Self-Organizing Systems on Various Organic Reactions

Birendra Kumar , School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur Chhattisgarh India 492010 , India ,

Deepti Tikariha , School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur Chhattisgarh India 492010 , India ,

Kallol K Ghosh , School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur Chhattisgarh India 492010 , India.

Amphiphiles self aggregate in solution to form micelles, reverse micelles and microemulsion. It has been established that micelle-forming self-organizing surfactants are better catalysts for various organic reactions. Recently micelle-forming surfactants continue to be an active area of research for pharmaceutical and industrial applications. Here we present some important organic reactions i.e. hydrolysis of ester, diester and triester in different surfactants. Various types of cationic surfactants such as cetyldiethylethanolammonium bromide (CDEABr), cetylpyridinium bromide (CPB), cetyltrimethylammonium bromide (CTAB) have been used. The observed rate data increases with the surfactant concentration initially and then decreases. The effects of head groups have also been investigated. Various model related to rate constant-surfactant concentration have been applied.

4 ,

Mixed micellization and interfacial behaviors of two novel cationic gemini surfactants and cationic, anionic and nonionic conventional surfactants ,

Nabel Negm , Applied Surfactant Laboratory, Petrochemicals Department, Egyptian Petroleum Research Institute , Egypt ,

Dalia Mahmoud , Applied Surfactant Laboratory, Petrochemicals Department, Egyptian Petroleum Research Institute , Egypt.

Two novel cationic gemini surfactants were synthesized throughout two steps reaction and characterized using different analytical tools. The interfacial and micellization properties of these surfactants were determined using surface tension and conductivity measurements at 25 oC. The behavior of mixed cationic gemini–conventional surfactant systems in solution and at interface have been studied by surface tension and conductivity measurements at 25 oC. The critical micelle concentration (cmc) values of the mixtures are lower than the values of individual surfactants and decrease with the increase in stoichiometric mole fraction of the three conventional surfactants in the solution. This shows nonideal, synergistic mixing of the two components. Other parameters calculated were cmc at ideal mixing conditions (cmc id), surface excess concentration (Gmax) and minimum area per surfactant head group (Amin). The Gibbs energy of micellization (Gomic), Gibbs energy of adsorption (G ads), mole fraction of surfactants in mixed micelles (Xm) and monolayers (X1), and interaction parameters (bm) were also evaluated. These values determined the contribution of the conventional components in the mixtures.

36 SIS2012

5 ,

Environmentally friendly surface active agents and their potential in Petroleum industry ,

Nabel Negm , Applied Surfactant Laboratory, Petrochemicals Department, Egyptian Petroleum Research Institute , Egypt.

The impact of environmentally friendly surface active agents in the oilfield applications was reviewed. The study involves three types of surfactants derived from naturally occurred compounds and their modification to obtain the oilfield additives. The targeted applications were additives for drilling fluids, inhibitors for metal corrosion in acidic media and biocides for different types of microorganisms. The main two parameters measured in these surfactants were the efficiency as additive for the desired application and their biodegradation tendency in the open environment.

6 ,

Molecular Dynamic Study of a lubricant system by NMR spectroscopic techniques. ,

A. S SARPAL , Indian Oil Corporation, R&D, Centre, Faridabad , India.

The present studies highlight the applications of NMR spectroscopic techniques for unraveling the unique structural features present in the high performance mineral(group II-III) and synthetic(group IV-V) base oils responsible for providing high performance lubricant properties. The viscosity-temperature and viscosity-pressure properties of base oils such as viscosity, viscosity index(VI), pour point, elastohydrodynamic(EHD) film thickness, and pressure-viscosity coefficient(PVC) have been correlated with the detailed hydrocarbon composition of base oils with an emphasis on the various types of methyl branched structures. Molecular dynamics parameters, such as Time Relaxation, Diffusion coefficient and energy of activation, estimated from the 1H & 13CNMR spectral studies have provided evidence of the factors responsible for the different viscosity-temperature or viscosity-pressure characteristics of base oils. The diffusion coefficients (D) has been found to be dependent upon the molecular structure, alkyl chain length, shape and size, hydrodynamic volume and alignment of molecules in a lubricant system constituting these base stocks. The study has enabled to propose a molecular structure of a base oil molecule which can be molecularly engineered for meeting high performance physico-chemical properties including tribolgy aspects.

7 ,

Structure of Concentrated Oil-in-Water Pickering Emulsions ,

Lisa Lotte , Ian Wark Research Institute, University of South Australia , Australia ,

Catherine Whitby , Ian Wark Research Institute, University of South Australia , Australia.

The response of particle-laden interfaces to applied stress is important for controlling the stability and function of emulsions found in food products, cosmetics and oil recovery.(1) The solid-like nature of particle-coated surfaces has been investigated for flat interfaces (2), single droplets (3) and pairs of drops (4). We have directly investigated the microstructure of bulk emulsions under stress. Our aim was to study how the structure of compressed Pickering emulsions is controlled.

Droplet structure was investigated in almost fully drained emulsions stabilized by silanised silica nanoparticles. Close packed droplets deform into polyhedral shapes. Estimates of excess surface area are reasonably consistent with the values predicted by considering the changes in drop geometry. The length

SIS2012 37

of the plateau borders increases with the volume fraction. The average number of contacts per drop agrees with predictions of the minimum coordination value required for mechanical stability. The droplet shapes became highly elongated as the volume fraction approached the condition where coalescence occurs. The particle layers are trapped at the surfaces of merging drops and buckling was observed.

The results showed that the Pickering emulsion morphology can be tuned by increasing the drop volume fraction. Drop deformation is similar to that observed in surfactant-stabilised emulsions. The structural changes observed in phase separating emulsions indicate that particle-laden interfaces possess significant elastic character.

References:

1. E. Dickinson, 2010. Food emulsions and foams: Stabilization by particles. Current Opinion Colloid Interface Sci. 15: 40. 2. E. J. Stancik, G. T. Gavranovic, M. J. O. Widenbrant, A. T. Laschitsch, J. Vermant and G. G. Fuller, 2003. Structure and dynamics of particle monolayers at a liquid‚Äìliquid interface subjected to shear flow. Faraday Discuss. 123: 145. 3. S. O. Asekomhe, R. Chiang, J. H. Masliyah, and J. A. W. Elliott, 2005. Some Observations on the Contraction Behavior of a Water-in-Oil Drop with Attached Solids. Ind. Eng. Chem. Res. 44: 1241. 4. S. Ata, 2008. Coalescence of Bubbles Covered by Particles. Langmuir 24: 6085.

8 ,

Flow of Concentrated Pickering Emulsions in Narrow Gaps ,

Melinda Krebsz , Ian Wark Research Institute, University of South Australia , Australia ,

Catherine Whitby , Ian Wark Research Institute, University of South Australia , Australia.

Controlling flow behaviour at narrow length scales is critical for applications of emulsions in porous media, microfluidic channels, spray nozzles and biological capillaries. Conventional rheology measures the bulk properties of emulsions by shearing samples between surfaces separated by several orders of magnitude greater than the size of the dispersed phase. The properties of fluids at micrometre length scales have been studied using microrheology. [1] Emulsions, however, contain hierarchical, meta-stable structures ranging in size from the nanometre to the macro-scale. [2] In the special case of particle-stabilised emulsions, solid particles may generate additional structure by aggregating to form networks with an elastic response to shear [3] or jamming in between drops to prevent liquid drainage [4]. We have investigated the flow and deformation of concentrated oil-in-water Pickering emulsions in narrow gaps using rheology and confocal fluorescence microscopy. A key result is that size effects in the flow behaviour are linked to structural arrangements in the emulsions. Weak attractions between the particles cause the formation of an interconnected network of drops and particles. Thus the flow of dense emulsions is controlled by the interactions between the particles. In addition, observations of droplet coalescence indicated there is a sharp destabilisation threshold. These results have implications for applications involving delivery (spreading, film formation, coating) of active ingredients from particle-stabilised emulsions. References: 1. C. Clasen, G.H. McKinley, 2004. Gap-dependent microrheometry of complex liquids. J. Non-Newt. Fluid Mech. 124: 1. 2. J. R. Stokes, W. J. Frith, 2008. Rheology of gelling and yielding soft matter systems. Soft Matter 4: 1133. 3. T. S. Horozov, B. P. Binks, T. Gottschalk-Gaudig, 2007. Effect of electrolyte in silicone oil-in-water emulsions stabilised by fumed silica particles, Phys. Chem. Chem Phys. 9: 6398.

38 SIS2012

4. R. M. Guillermic, A. Salonen, J. Emile, A. Saint-Jalmes 2009. Surfactant foams doped with laponite: unusual behaviors induced by aging and confinement. Soft Matter 5: 4975.

9 ,

Ionization By pH and Anionic Surfactant Binding Gives the Same Thickening Effects ,

Filipe Antunes , University of Coimbra , Portugal ,

Luis Alves , University of Coimbra , Portugal ,

Bjorn Lindman , University of Coimbra , Portugal ,

Bjorn Klotz , BASF Personal Care and Nutrition GmbH , Germany ,

Axel Bottcher , BASF Personal Care and Nutrition GmbH , Germany ,

Hans-Martin Haake , BASF Personal Care and Nutrition GmbH , Germany.

Physical properties of aqueous solutions of hydrophobically modified cross-linked polyacrylic acids change quite extensively as the polymer is charged up. A study is carried out concerning the similarities between two polymer ionization processes, i. e. by pH increment and anionic surfactant addition. The two processes charge the polymer by distinctly different mechanisms. At sufficiently high pH the carboxylic groups of the polymer are all virtually ionized and the polymer is, therefore, fully charged. The effective repulsion among the charged groups due to the entropy of the counterions promotes an increased stiffness as well as an expansion of the polymer particles. We investigate here how the ionization and swelling will be if, instead of high pH, the polymer is placed at low pH conditions but associated to ionic surfactants. Surfactants associate to the polymer both in a non-cooperative way by the binding of individual surfactant molecules and in a cooperative w ay as micelles since the polymer promotes surfactant self-assembly. This binding leads to a highly charged polymer-surfactant complex and leads to an osmotic swelling as well. The swelling and the gelation were monitored by rheology and dynamic light scattering, of polymer solutions at different pH’s and by adding ionic surfactants at low pH. The results show that ionization by surfactants and by pH lead to approximately the same gelation degree, as can be seen by similar viscosity values. Both processes result in dramatic viscosity increases, up to 8 orders of magnitude. More hydrophobic surfactants, with longer alkyl chain, are shown to be more efficient as enhancers of swelling and gelation. The network that is formed at high pH or at sufficiently high concentration of surfactant can be weakened or even disrupted if monovalent or divalent salts are added, demonstrating the role of counterion entropy.

10 ,

Particle-laden fluid interfaces: Structure, dynamics and microrheology ,

Alma Mendoza , Universidad Complutense , Spain ,

Raquel Chulia Jordan , Universidad Complutense , Spain ,

Laura Bonales , Universidad Complutense , Spain ,

Fernando Martinez Pedrero , Universidad Complutense , Spain ,

Ramon Rubio , Universidad Complutense , Spain ,

Francisco Ortega , Universidad Complutense , Spain.

SIS2012 39

Latex particles attached to the octane/water interface have been experimentally studied. The phase diagram has been determined by videomicroscopy for a broad particle size range. The diffusion coefficient has been measured by the particle-tracking technique and has been modeled using a Langevin equation that takes into account the interaction between the particles. Finally, the microparticles have been used as probes to determine the surface shear viscosity of polymer monolayers over a broad range of molecular weights. The results have been analyzed using several theoretical approaches that lead to the same values of the surface shear viscosity.

11 ,

Evaporation of super-spreader solution droplets: Effects of concentration, temperature and relative humidity ,

Hezekiah Agogo , Universidad Complutense , Spain ,

Sergey Semenov , Loughborough University , United Kingdom ,

Francisco Ortega , Universidad Complutense , Spain ,

Ramon Rubio , Universidad Complutense , Spain ,

Victor Starov , Loughborough University , United Kingdom ,

Manuel Velarde , Universidad Complutense , Spain.

The spreading and evaporation process of SILWET L77 solutions onto a hydrophobic substrate has been measured as a function of concentration, temperature and relative humidity. A theoretical model has been developed that explains two of the three stages of the evaporation process. Universal curves are predicted for each of the two stages, and a comparison has been done for SILWET L77 and SDS solutions.

13 ,

Use of continuous oil phase microemulsions in the formulation of completion fluids ,

Vanessa Gonzalez , PDVSA Intevep , Venezuela ,

Raquelisa Arellano , PDVSA , Venezuela ,

Luis Marcano , PDVSA Intevep , Venezuela ,

Edward Martinez , PDVSA Intevep , Venezuela ,

Xiomara Gutierrez , PDVSA Intevep , Venezuela.

Microemulsions technology can have potential application in the formulation of drilling, completion and workover fluids. In this research, a water in oil (W/O) microemulsion was formed which was stabilized with a mixture of fatty acids (C16-C18) and their respective salts of alkanolamine. In addition, an alcohol of low chain C3 to C6, was used as co-surfactant. This microemulsion has the ability to incorporate high percentages of water and salinity (KCl) until achieving appropriate viscosity and density values. In addition, the W/O microemulsion has the required stability properties to be applied as a completion fluid for oil based fluids. It may be recommended the use of an oil based fluid during the completion when an oil based fluid is applied in the drilling process in order to maintain continuity. An advantage of the microemulsion would be to eliminate the problems caused when an oil based fluid is changed for a water

40 SIS2012

based fluid, such as, the clear solids-free brines. In general, these problems are the following: wettability changes of the medium and emulsion formation, which are two causes of formation damage.

In the formulation of the W/O microemulsion, the results indicated the following observations: the microemulsion formulation is adaptable to different types of oil; for instance, aromatic oil and hydrotreated mineral oil; it is stable to the content of KCl salt in a concentration range from 0.5 to 2% w/v; high tolerance to the percentage of dispersed phase between 10% v/v and 40% v/v of H2O; the rheological profile is Newtonian; according to static stability, microemulsions were stable between 23

oC

and 40 oC; these were dynamically stable in the temperature range between 180 and 250

oF, depending

on the percentage of H2O and oil type. Finally, this microemulsion produces low percentage of formation damage.

14 ,

Surfactant Tasks in Enhanced Oil Recovery Processes: Oil Displacement, Wettability Alteration, Foam Stability ,

Robert Li , Shell , United States ,

Aparna Raju Sagi , Rice University , United States ,

Maura Puerto , Rice University , United States ,

Mehdi Salehi , Tiorco , United States ,

Charles Thomas , Tiorco , United States ,

Jonathan Kwan , ConocoPhillips , United States ,

George Hirasaki , Rice University , United States ,

Clarence Miller , Rice University , United States.

The objectives of surfactant processes for enhanced oil recovery are to mobilize trapped oil and to drive it along with any mobile oil present to production wells for recovery. Challenges of finding suitable surfactants for use at temperatures up to 120°C and for hard brines with both high and low salinities are discussed. Surfactants must provide low interfacial tensions (IFTs) with crude oil at reservoir conditions and, in addition, exist as single-phase aqueous solutions for injection, in some cases with water-soluble polymers of high molecular weight also present. In heterogeneous, oil-wet reservoirs a combination of IFT and wettability alteration of formation rocks must effect oil recovery from regions of low permeability within the reservoir. When foam is used instead of polymer for mobility control, foam with adequate stability even in the presence of crude oil is needed. Examples based on recent work in our laboratory are discussed.

18 ,

Oligofructose fatty acid esters create air/water interfaces with extremely high moduli ,

Silvia van Kempen , Wageningen University , Netherlands ,

Carmen Boeriu , Wageningen University and Research Centre , Netherlands ,

Henk Schols , Wageningen University , Netherlands ,

SIS2012 41

Erik van der Linden , Wageningen University , Netherlands ,

Leonard Sagis , Wageningen University , Netherlands.

Two main classes of currently used food-grade emulsifiers are proteins and low molecular weight surfactants. Low molecular weight surfactants lower the surface tension to a greater extent than proteins. Proteins, however, tend to form a visco-elastic network at the interface leading to a high dilatational modulus while low molecular weight surfactants generally create interfaces with a low dilatational modulus. Inspired by amphiphilic block oligomers, oligofructose was esterified to a fatty acid in an attempt to create a food-grade surfactant that is capable of lowering the surface tension considerably while also creating an interface with a high dilatational modulus. In order to create molecules with different functionality the fatty acid chain length was varied: butyric, caprylic, capric, lauric, palmitic and stearic acids were used. Surface tension and surface dilatational modulus were determined using an automated drop tensiometer, while the surface shear modulus was determined using a rheometer equipped with a double wall ring geometry. The results were compared to those obtained with sucrose esters of fatty acids. The extent to which the surface tension is lowered depends on the length of fatty acid: the longer the fatty acid the lower the surface tension. Palmitic acid and stearic acid esters are particularly efficient in lowering the surface tension. Esters (with either sucrose or oligofructose as the hydrophilic head group) of shorter fatty acids (lauric acid or smaller) give a low dilatational modulus while esters (both oligofructose and sucrose) of longer fatty acid chains (palmitic acid or stearic acid) give an extremely high dilatational modulus. The shear modulus of esters of shorter fatty acids is very low. When studying esters of palmitic acid and stearic acid there is a clear difference between sucrose esters or oligofructose esters. Oligofructose esters do give a high shear modulus while moduli of sucrose esters were very low. Thus, with the palmitic acid and stearic acid esters we were able to synthesize molecules that considerably lower the surface tension of an air/water interface and give an extremely high dilatational and shear modulus.

19 ,

On the thermodynamics and kinetics of cyclodextrin-bolaform surfactant host-guest compounds ,

Artur Valente , Dept. Chemistry, University of Coimbra , Portugal ,

Olle Soderman , Physical Chemistry 1, Lund University , Sweden.

Cyclodextrins are torus-shaped oligosaccharides with the primary hydroxyl groups at the narrow side and the secondary hydroxyl groups at the wide side of the glucose units, making it hydrophilic as a whole. However, the interior surface of the truncated cone, normally considered as the site of the guest molecules, is hydrophobic. These hydrophobic cavities provide a potential for the formation of inclusion complexes with a large variety of organic, and inorganic compounds. Bolaform surfactants are of special interest as guest molecules due to the balance of several intermolecular forces: the hydrophobic effect which tends to protect the alkyl chain from the aqueous environment, the requirement of dehydration of the head groups during complex formation, as well as effects due to steric hindrances. Bolaform amphiphiles also show inclusion dynamics significantly different from those of homologous univalent surfactants. This is due to the fact that a charged headgroup has to pass through the hydrophobic CD cavity. The dynamic properties will depend on the size of cyclodextrin cavity, the surfactant end-groups and the size of alkyl chain. In this communication, the effect of alkyl chain length of alkane-1,n-bis(trimethyl ammonium bromide), n=8, 10 and 12, bolaform surfactants on the supramolecular

association with - and -cyclodextrin is analysed by using electrical conductivity, isothermal titration calorimetry and 1H NMR spectroscopy. The association constant, the enthalpy, and the entropy of formation were determined. The obtained thermodynamic parameters are compared with parameters for the micelle formation of a related cationic surfactant and with those obtained for association of

42 SIS2012

cyclodextrins with Gemini surfactants. The kinetics for - cyclodextrin is slow, associated with high activation energies for both association and dissociation of the complex. The rates increased with a decrease in the number of methylene groups in the hydrocarbon chain. The role of water inside the cyclodextrin cavity on the association process will be discussed.

20 ,

Surfactant Additives used as Friction and Wear Reducers for Water-Based Drilling Fluids ,

Franklin Quintero , PDVSA Intevep , Venezuela ,

Jose Gonzalez , PDVSA Intevep , Venezuela.

In the oil industry, there are drilling fluids of different nature, classified according to the external fluid phase as: water-based, oil-based, and pneumatic or gas-based systems. Basically, drilling fluids are composed of a base fluid (water or oil), a weighting material (Ba2SO4, Fe2O3 or CaCO3) and other additives to control rheological properties, fluid losses and shale inhibition, among others. In water-based drilling fluids (WBFs) the lubricity function is very important, due to the existence of frictional forces during all stages of well construction (drilling and completion). These forces can be minimized by increasing the lubricity of the circulating working fluid. The dominant wear modes include impact wear, abrasion, and slurry erosion, and when not controlled or predicted they can cause catastrophic failures of the equipment and the wellbore. Abrasion and erosion wears are caused mainly by the content of solid particles used as weighting material in the drilling fluid formulation. The objective of this work was to develop new lubricant and wear reducing additives in order to improve the performance of water based drilling fluids. In this work, the friction reducing properties of a surfactant mixture (anionic/non-ionic) were established by measuring the coefficient of friction (CF) of different WBFs formulated with two weighting materials (hematite and calcium carbonate). Besides, it was study the surfactant mixture adsorption on hematite particles and its influence over the wear behavior of hematite particles on WBFs. It was established that the evaluated surfactant additive can reduce significantly the CF independently of the weighting materials used, the addition of the surfactant mixture at 1% w/v to the drilling fluid formulations lead to a reduction in CF up to 57% compared to the formulations without surfactant, according to the weighting material used. The results showed that the surfactant system studied adsorbs on hematite particles and this adsorption was influenced by the pH of the solution. Additionally, the results obtained in the abrasive test suggest that surfactant adsorption could be related to the wear reduction of hematite in this system.

21 ,

Investigation of the Solubility and Interfacial Behavior of Various Asphaltenes under Severe Refinery and Transport Conditions ,

Guangzhe Yu , Institute for Applied Surfactant Research and School of Chemical, Biological & Materials Engineering, University of Oklahoma, Norman, OK , United States ,

Kyle Karinshak , Institute for Applied Surfactant Research and School of Chemical, Biological & Materials Engineering, University of Oklahoma, Norman, OK , United States ,

Ian Pleasant , Institute for Applied Surfactant Research and School of Chemical, Biological & Materials Engineering, University of Oklahoma, Norman, OK , United States ,

Andrew Woodside , ConocoPhillips, Bartlesville, OK , United States ,

SIS2012 43

Jeffrey Harwell , Institute for Applied Surfactant Research and School of Chemical, Biological & Materials Engineering, University of Oklahoma, Norman, OK , United States ,

Brian Grady , Institute for Applied Surfactant Research and School of Chemical, Biological & Materials Engineering, University of Oklahoma, Norman, OK , United States.

In order to understand the behavior of asphaltenes in bulk crude oil under refinery and transport conditions, two pressurized cells designed to operate at elevated temperature (up to 200

oC) were built.

With these devices we were able to test a) solubility properties of various asphaltenes in water with varying salinity, b) interfacial properties at the organic liquid-air interface with asphaltenes dissolved in model organic liquids, i.e. toluene and c) interfacial properties at the organic liquid-aqueous interface again including understanding the influence of salinity in the aqueous phase. The ultimate purpose of this study is to acquire the fundamental knowledge of various asphaltenes, which in turn can improve the current art of handling crude oil-water mixtures in oil extraction, transport and refining.

22 ,

pH-dependent polyampholyte SDS interactions in highly diluted aqueous solutions and in reverse microemulsion droplets ,

Joachim Koetz , University of Potsdam , Germany ,

Mabya Fechner , University of Potsdam , Germany.

Our research was focused on interactions between the anionic surfactant SDS and a synthetic alternating polyampholyte, i.e. poly(N,N’-diallyl-N,N’-dimethyl-alt-maleamic carboxylate) (PalH). In diluted aqueous solutions potentiometric measurements using a SDS-selective electrode indicate a pH-dependent quite complex interaction mechanism with non-cooperative, electrostatic and cooperative hydrophobic interactions. Isothermal titration calorimetry (ITC) shows, that the early stage hydrophobic binding is an exothermic process. The following endothermic procedure is entropy driven due to electrostatic interactions between the SDS molecules and the cationic functional groups of PalH. After adding a low molecular salt, i.e. NaCl, the interaction mechanism becomes pH-independent, and SDS-micelles interact with the polyampholyte [1]. By incorporating PalH into a SDS-based water-in-oil microemulsion, the droplet-droplet interactions can be controlled in dependence on pH. At pH=9 more attractive droplet-droplet interactions lead to an increase of conductivity, in contrast to pH=4, where the conductivity is decreased. In agreement with additional micro-DSC measurements, one can conclude that the location of the polyampholyte inside of the microemulsion droplet can be controlled by varying the pH [2]. That means at pH=4 the cationic PalH is attached at the oppositely charged head groups of the surfactant film, in contrast to pH=9, where the amphoteric PalH is located more inside of the droplet in a more coiled conformation. Recently, we have shown that this concept of a pH-dependent tuning of the polyampholyte-surfactant film can be expended to more hydrophobic-modified polyampholytes, too [3]. Reference: [1] M. Fechner, S. Kosmella, J. Koetz, pH-dependent polyampholyte SDS interactions J. Colloid Interface Sci. 345 (2010) 384-391 [2] M. Fechner,M. Kramer, E. Kleinpeter, J. Koetz, Polyampholyte-modified ionic microemulsions Colloid Polym. Sci. 287 (2009) 1145-1153 [3] M. Fechner, J. Koetz, Polyampholyte-Surfactant Film Tuning in Reverse Microemulsions Langmuir 27 (2011) 5316-5323

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23 ,

Environmentally friendly nonionic surfactants: synthesis, surface activity and their impact as corrosion inhibitors for petroleum equipment in acidic media ,

Nabel Negm , Petrochemicals Department, Egyptian Petroleum Research Institute , Egypt ,

Salah Tawfik , Petrochemicals Department, Egyptian Petroleum Research Institute , Egypt.

Four water-soluble non-ionic ethoxylated surfactants based on vanillin were synthesized (VE15, VE20,

VE40, and VE60). The chemical structures of these surfactants were confirmed using FT-IR and 1H NMR

spectra. Surface tension as a function of concentration of the surfactant in aqueous solution was measured

at 25, 40 and 55°C. From these measurements critical micelle concentration (CMC), effectivenes

The surface activity measurements showed their high tendency towards adsorption and micellization and

their good surface tension reduction, low interfacial tension. The emulsion stability measurements showed

the applicability of these surfactants as emulsifying agents. The thermodynamic parameters of micellization

(ΔGmic, ΔHmic, ΔSmic) and adsorption (ΔGads, ΔGads, ΔSads) showed their tendency towards

adsorption at the interface and also micellization in the bulk of their solutions. The inhibition of the

synthesized surfactants towards the corrosion of carbon steel in acidic media of 1M HCl was studied by

weight loss measurements, potentiodynamic and electrochemical impedance spectroscopy (EIS). The effect

of concentration and immersion time was studied. The inhibition efficiency depends on both of

concentration and molecular structure of the inhibitors. It was found that all the inhibitors were effective

inhibitors and their inhibition efficiency was significantly increased with increasing the concentration.

Polarization curves revealed that the used inhibitors represent mixed-type inhibitors, which inhibits the

cathodic and anodic directions of the corrosion reaction in the acidic media. The adsorption of these

inhibitors led to a reduction in the double layer capacitance and an increase in the charge transfer resistance.

The inhibitors adsorption was found to obey Langmuir isotherm. Also the relation between surface activity

and corrosion inhibition efficiency revealed that increasing the ethoxylated chain length of the inhibitor

molecules increases their surface activity and the tendency towards adsorption at the interfaces. Moreover,

increasing the adsorption tendency increases the amounts of adsorbed molecules onto the metal surface,

which consequently increase the surface coverage values. As a result, the metal surface is protected from

the dissolution as the action of the acid solution. The inhibition efficiencies obtained from the used

techniques were in good agreement with each other.

24 ,

Lubrication of brass surfaces with fatty acids: from film formation to friction ,

Juliette Cayer-Barrioz , LTDS-CNRS UMR5513-Ecole centrale de Lyon , France.

The lubrication mechanisms of fatty acids are investigated using a tribometre that simultaneously allows the contact visualization and the friction measurement under controlled contact kinematics. We first study the phase behavior in water of a mixture of natural long chain fatty acids (FAM) in association with ethylenediamine (EDA) and report a rich polymorphism depending on the composition. At a fixed EDA/FAM molar ratio, we observe upon dilution a succession of organized phases going from a lamellar phase to a hexagonal phase and, finally, to cylindrical micelles. The lamellar phases consist of nanometric flat bilayers of fatty acid molecules organized in periodic stacks and separated by a distilled water / ethylene diamine solution. The film formation capability of the lamellar phase is determined: a peculiar evolution is observed as a thick film grows in the contact with time before it reaches a stabilized value. It is also shown that the formation of this highly viscous boundary film leads to starved lubrication. The modelling of the film build-up process allows us to quantify the rheological properties of the boundary film in terms of high viscosity and very low piezoviscosity. Second, the sheared boundary film exhibits a constant thickness and a rather low friction response that can be correlated to its piezoviscous properties.

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The role of the bilayer swelling by addition of napthenic oil is discussed on the film formation capability as well as the friction behaviour.

25 ,

Thermosensitivity of superhydrophobic surfactants polymeric complexes ,

Kuralay Korzhynbayeva , Al-Faraby Kazakh National University , Kazakhstan ,

Sagdat Tazhibayeva , Al-Faraby Kazakh National University , Kazakhstan ,

Kuanyshbek Musabekov , Al-Faraby Kazakh National University , Kazakhstan ,

Azymbek Kokanbayev , Al-Faraby Kazakh National University , Kazakhstan ,

Ardak Sapieva , Astana Medicinal University , Kazakhstan ,

Gulzhan Seit , Al-Faraby Kazakh National University , Kazakhstan.

The complex formation superhydrophobic surfactants of alkylammonium salts containing two hydrocarbon radicals with long chains and two polar groups with polyacrylic acids and polymethacrylic acids is studied. It is shown that at change of temperature from 293 K to 333 K difference in surfactants polymeric complexes viscosity values by heating and cooling system mode is observed. It is explained from a position of change electrostatic attraction forces and hydrophobic interactions parities.

26 ,

Adsorption mechanisms of surfactant mixtures on non-polar solid surfaces and importance for the stability of dispersions ,

Wolfgang von Rybinski , University of Duesseldorf , Germany ,

Meriem Jabnoun , Schwan-Stabilo Cosmetics , Germany.

Mixtures of anionic and nonionic surfactants are widely used in numerous applications. In these applications the different surfactants interact with each other and with the surfaces in the system. This regards especially the dispersion of solid particles in aqueous systems. The adsorption mechanism of surfactants at the solid-liquid interface is one important parameter for the stability of dispersions. In the present study the adsorption process of anionic surfactants, nonionic surfactants and their mixtures on non-polar surfaces is investigated using a combination of adsorption isotherms, calorimetry and Atomic Force Microscopy (AFM) in order to propose a model for the adsorption of mixtures. In addition to this, a comparison is done between the adsorption parameters and the stabilization behavior of solid particles by mixtures of different anionic surfactants having main structural differences and the nonionic surfactant. The results obtained by the combination of the different techniques show a strong influence of the structure of the anionic surfactant on the adsorption behavior of the mixtures. The surfactants are adsorbed in a flat orientation to the hydrophobic surface with a further aggregation to micellar-like aggregates at higher concentrations. This could be assumed from the calorimetric data in combination with the adsorbed amounts dependent on the surface coverage. AFM measurements of the structure of the mixed surfactant layers on flat surfaces confirmed the results of adsorption experiments. They show semi-cylindrical structures starting already below the critical micelle concentration except for the single surfactant system of alkane benzene sulfonate. For mixtures of alkane benzene sulfonate with the nonionic surfactant structures of the adsorbed layer on the graphite surface can be seen, however. The

46 SIS2012

structures have different dimensions depending on the type of the system. A model for the structure is discussed. A direct correlation of the results of the adsorption measurements to the stability of the dispersions was possible.

27 ,

Tribological properties of aqueous solutions as result of breach of equilibrium double electric layer ,

Natalia Kochurova , St.Petersburg University , Russian Federation ,

Nail Abdulin , St.Petersburg University , Russian Federation.

This work is devoted to studying of the dynamic surface tension of solution of surfactants, nonorganic salts, polymers and their complexes. Investigation of the formation kinetics of equilibrium surface tension makes it possible to understand the nature and structure of fresh surface. Surface electrolization was estimated from experiment by means of adsorption equation for nonequilibrium surface layer, in which surface tension changes with the change of surface electrical potential [1]. These results explain the increase of surface tension of surfactant solution at small surface age [2] and the existence of minimum point on isoterm of the dynamic surface tension of nonorganic salt solution [3]. This effect is associated with existence of tribological properties of investigated solutions. Suppoted by the Grant NSH-4464.2012.3. Reference: [1] N.N.Kochurova , A.I.Rusanov. Uspekhi Khimii. 1993.62.1150 (in Russian ) [2] N.N.Kochurova, N.G.Abdulin,I.A.Tichomirov, I.I.Germasheva.Vestnic of St.Petersburg University. Ser.4,2011, Vip.4 (in Russian) [3] N.N.Kochurova, A.I.Rusanov, N.O.Mirsachmetova. Dokl.Akad.Nauk. 1991. V.316, N6, 1425(in Russian)

28 ,

The role of substrate electrical charge on the drying of colloidal suspensions ,

Carmen L. Moraila-Martinez , University of Granada , Spain ,

Miguel Cabrerizo-Vilchez , University of Granada , Spain ,

Miguel A. Rodriguez-Valverde , University of Granada , Spain.

Drying droplet of colloidal suspension has been widely investigated in many fundamental studies due to the several applications that can be used, for example printing, bioassay manufacturing, colloidal assembly/templating, nanowires fabrication, cosmetics and microelectronics. Different methods have been developed to create structured patterns, but self-assembly by evaporation is one of the most promising ideas to fabricate nano-scale patterns [1-2]. Evaporation of liquid drops is a very complex phenomenon due to the strong dependence on the experimental conditions (drop volume, temperature and humidity) and to very large time scales of the evaporation process. Under these conditions, the reproducibility of contact line dynamics of evaporating drops is very poor. Therefore a standard procedure of evaporation dynamics is required.

In this work, we propose a method to standardize contact line dynamics of freely evaporating drops. We used a motorized-micrometer syringe to change the drop volume and thus to control the shrinking of drop [3]. In this way, we were able to reproduce the first stages of drop evaporation at shorter times [Fig. 1]. In order to study the nanoparticle deposits on driven contact lines, we applied our method to nanoparticle drops and we analyzed the effect of several parameters such as particle and substrate

SIS2012 47

wettability, colloidal concentration, particle size and electrical interactions (particle-particle and particle-substrate) on the nanoparticle deposits [Fig.2]. The main difference of our experiments compared with freely- drying nanoparticle drops was the constant particle concentration during the entire process.

Fig 1. Contact line dynamics during our method of shrinking drop. Fig 2. Images of nanoparticle deposits obtained by Confocal, Optical and AFM microscopes. References [1] R.D. Deegan, O. Bakajin, T. F. Dupont, G. Huber, S. R. Nagel and T. A. Witten., Nature 389, 827-829 (1997). [2] R. Bhardwaj, X. Fang, P. Somasundaran and D. Attinger, Langmuir 26 (11), 7833-7842, (2010). [3] H. Tavana and A.W. Neumann,Colloids and Surfaces A: Physicochemical and Engineering Aspects 282-283, 256-262 (2006).

29 ,

Cleavable Cationic Gemini Surfactants ,

Ali Reza Tehrani Bagha , Department of Chemical and Biological Engineering, Chalmers University of Technology , Sweden ,

Krister Holmberg , Department of Chemical and Biological Engineering, Chalmers University of Technology , Sweden.

This research project concerns investigations of ester-containing cationic gemini surfactants (esterquat and betaine ester types). These dimeric surfactants are compared with their monomeric counterparts. Series of both stable and ester-containing cationic gemini and monomeric surfactants were synthesized and their physical-chemical properties were investigated. The critical micelle concentration (CMC) values of the ester-containing gemini surfactants were generally 10-20 times smaller than those of the corresponding monomers. The alkyl chain length was decisive of the CMC while the length and the nature of spacer did not affect the CMC much. The low CMC of the gemini surfactants resulted in very high efficiency in covering surfaces in adsorption experiments, in stabilizing emulsions and foams, and in solubilizing hydrophobic dyes. The micellar aggregation number of the surfactants was determined with steady state and with time-resolved fluorescence quenching. Based on calculations of diffusion coefficients obtained from NMR measurements, a growth of the micelles with increasing surfactant concentration was observed for some of the gemini surfactants and a structure of interdigitated micelles was proposed for all the geminis. Studies of the chemical hydrolysis showed that the betaine ester type surfactants were much more susceptible to alkaline hydrolysis than the esterquat type surfactants. It was also found that the ester-containing geminis hydrolyzed more readily than the ester-containing monomeric surfactants, which was attributed to an anchimeric assistance by the second quaternary ammonium head group. In contrast to the results from the chemical hydrolysis the monomeric ester-containing surfactants biodegraded faster than the corresponding gemini surfactants. The low rate of biodegradation of the ester-containing

48 SIS2012

geminis was found to be due to the dicationic species formed on hydrolysis of the two ester bonds being very resistant to further biodegradation.

30 ,

Cationic ester-containing gemini surfactants: Chemical hydrolysis and biodegradation ,


Hans Oskarsson , Department of Chemical and Biological Engineering, Chalmers University of Technology , Sweden ,

C.G. van Ginkel , Akzo Nobel Chemicals Research, 6800 SB Arnhem, The Netherlands , Netherlands ,

Krister Holmberg , Akzo Nobel Chemicals Research, 6800 SB Arnhem, The Netherlands , Sweden.

This research project concerns investigations of ester-containing cationic gemini surfactants (esterquat and betaine ester types). These dimeric surfactants are compared with their monomeric counterparts. Series of both stable and ester-containing cationic gemini and monomeric surfactants were synthesized and their physical-chemical properties were investigated. The critical micelle concentration (CMC) values of the ester-containing gemini surfactants were generally 10-20 times smaller than those of the corresponding monomers. The alkyl chain length was decisive of the CMC while the length and the nature of spacer did not affect the CMC much. The low CMC of the gemini surfactants resulted in very high efficiency in covering surfaces in adsorption experiments, in stabilizing emulsions and foams, and in solubilizing hydrophobic dyes. The micellar aggregation number of the surfactants was determined with steady state and with time-resolved fluorescence quenching. Based on calculations of diffusion coefficients obtained from NMR measurements, a growth of the micelles with increasing surfactant concentration was observed for some of the gemini surfactants and a structure of interdigitated micelles was proposed for all the geminis. Studies of the chemical hydrolysis showed that the betaine ester type surfactants were much more susceptible to alkaline hydrolysis than the esterquat type surfactants. It was also found that the ester-containing geminis hydrolyzed more readily than the ester-containing monomeric surfactants, which was attributed to an anchimeric assistance by the second quaternary ammonium head group. In contrast to the results from the chemical hydrolysis the monomeric ester-containing surfactants biodegraded faster than the corresponding gemini surfactants. The low rate of biodegradation of the ester-containing geminis was found to be due to the dicationic species formed on hydrolysis of the two ester bonds being very resistant to further biodegradation.

31 ,

Cationic Ester-Containing Gemini Surfactants: Adsorption at Tailor-Made Surfaces Monitored by SPR and QCM ,



SIS2012 49

Adsorption of a series of ester-containing cationic surfactants at a surface containing 90% methyl groups and 10% carboxyl groups was studied by two surface analysis techniques, surface plasmon resonance (SPR) and quartz crystal microbalance (QCM). Such a surface, which is at the same time hydrophobic and negatively charged, is of interest as a model for many polymeric surfaces. Two different types of ester gemini surfactants and their monomeric counterparts were included together with nonester containing surfactants of similar structure. The results show that the Gemini surfactants give the same adsorbed amount at the surface as the monomeric surfactants when compared at the same bulk concentration normalized to the critical micelle concentration (cmc) in bulk. Since the cmc of the geminis is around 20 times lower than the cmc of the corresponding monomeric surfactants, the gemini surfactants are much more effective in covering the surface. The two techniques gave similar relative values but the QCM values were always higher than those from SPR, which is due to the former method taking also adsorbed water into account. The adsorption, as measured by both methods, was found to follow closely the Langmuir adsorption model.

32 ,

Stable and Ester-Containing Cationic Gemini Surfactants: Shape, Size and Solubilization of Micelles ,


Krister Holmberg , Department of Chemical and Biological Engineering, Chalmers University of Technology , Sweden ,

Rajdeep G. Singh , Department of Chemical and Biological Engineering, Chalmers University of Technology , Sweden ,

Magnus Nyden , Department of Chemical and Biological Engineering, Chalmers University of Technology , Sweden ,

Lars Nordstierna , Department of Chemical and Biological Engineering, Chalmers University of Technology , Sweden ,

Joakim J. Karnbratt , Department of Chemical and Biological Engineering, Chalmers University of Technology , Sweden ,

50 SIS2012

Jan-Erik Lofroth , Department of Chemical and Biological Engineering, Chalmers University of Technology , Sweden.

The micellar aggregation number of the surfactants was determined with time-resolved fluorescence quenching. It was found that among the different structural variables studied, the length of the spacer was the most important factor affecting the aggregation number. The Gemini surfactant with the longest spacer, had the lowest aggregation value (30). The higher aggregation numbers of other geminis (>80 alkyl chains per micelle) was an indication of slightly elongated micelles. Based on the calculations from diffusion coefficients obtained from NMR measurements, a micellar growth with increasing surfactant concentration was observed for four out of the six gemini surfactants and a structure of interdigitated micelles was proposed for all the gemini surfactants. The presence of ester bonds in the tails gave rise to a more pronounced growth in the micelles possibly because these bonds reduced the number of available conformations of the alkyl chains.

Proposed interdigited micelles based on diffusion NMR calculations and time-resolved

fluorescence quenching aggregation numbers for the gemini surfactants

33 ,

Natural surfactant for solubilizing Crude oil ,

Eshu Middha , Indian Institute of Technology Madras , India ,

Gaugin Gyanendra Singh , Indian Institute of Technology Madras , India ,

Anoop Sonker , Indian Institute of Technology Madras , India ,

Susy Varughese , Indian Institute of Technology Madras , India.

Oil spills in the marine environment are the probable result of oil extraction, transport, and use. Oil spill response options include mechanical removal, burning, and dispersion. Dispersion is intended to transfer oil from the sea surface to the water column, thereby reducing its impact on pelagic organisms and shorelines. The effectiveness of a dispersant is a function of the chemical structure of the dispersant, the oil to be dispersed and water temperature. In addition to the intrinsic properties of the dispersant, oil, and seawater, dispersant effectiveness is dependent on contact time. The contact time is that period for which dispersant is applied to the oil and mixing occurs. The effectiveness of a dispersant is not only dependent on when it is applied to a spill and how long afterward mixing occurs, but also on the amount of dispersant applied, expressed as the DOR (Dispersant to Oil ratio). Two non-ionic surfactant Soapnut powder (Sapindus mukorossi) and extracted Saponin applied to Dubai crude oil under a combination of different contact times, and different DOR’s at 28°C. This study is to determine the effectiveness of natural surfactant Soapnut powder and Saponin in oil spill dispersion and compare with each other so that we can determine that whether it is worth to extract Saponin from Soapnut. Results indicated that an

SIS2012 51

increase in the DOR from 1:10 to 5:1 resulted in an increase in oil dispersion in water for both surfactants but effectiveness of Soapnut powder increases dramatically as compared to Saponin solution with increase in DOR. At high contact time Soapnut powder shows same dispersant effect as Saponin solution.

34 ,

Experimental Study on the Interactions between Polyvinylpyrrolidone and Cationic Gemini /Conventional Surfactants ,

M Kamil , AMU Aligarh , India ,

M Suhail , AMU Aligarh , India ,

Kabir uD-Din , AMU Aligah , India.

Surfactants have very special qualities that make them invaluable to chemical, petrochemical and in the petroleum industry. A novel class of surfactants called gemini (dimeric), consisting of two hydrophobic chains and two hydrophilic head-groups united by a short (rigid or flexible) spacer, has been attracting attention of both scientists and engineers due to their superior properties as compared to corresponding conventional surfactants in the recent past. The geminis have much smaller cmc values, much greater efficiency in reducing surface tension than expected, better wetting properties, and other unusual behaviors. Because of their higher surface activity, these surfactants are used as promising surfactants in industrial detergency and emulsification, are cost effective in areas such as, soil clean up, enhanced oil recovery among others. Despite many studies on interactions between neutral polymers and anionic surfactant, the understanding of the nature of the neutral polymer-cationic surfactant interactions is still incomplete. The purpose of this study is therefore, to investigate the interaction between cationic gemini surfactant and neutral polymer polyvinylpyrrolidone on neutral polymer/cationic surfactant interaction. The interactions of a gemini surfactant (14-6-14) and their conventional counterpart cetyltrimethylammonium bromide (CTAB), tetradecyltrimethylammonium bromide (TTAB) with polyvinylpyrrolidone (PVP) have been investigated using conductivity technique. The critical micelle concentration (CMC) was determined by this method. The measurements were performed on an ELICO (type CM 82T) bridge equipped with platinized electrodes (cell constant = 1.02 cm-1). The conductivity runs were carried out by adding progressively concentrated surfactant stock solution into the thermostated solvent or solvent containing PVP. The critical micellar concentration of the pure surfactant used was obtained from the plots of specific conductivity (κ) as a function of the surfactant concentration. The CMC values were taken from the intersection of the two straight lines drawn before and after the intersection point in the κ vs. surfactant concentration plots. As in case of the polymer surfactant mixtures the plots of κ vs [surfactant] showed two breaks, the CAC was determined by the intersection of first and second linear parts and the CMC in this case was the intersection point of second and third linear parts. The results indicate that there is interaction between polymer PVP and surfactants (Gemini, CTAB, TTAB). Gemini surfactant shows strong interaction as compared to their conventional counterparts. The free energy of micellization was calculated and is found in good agreement with the extent of interaction.

35 ,

Triton-X100 transfer across the water/dodecane interface: dynamic interfacial tension behavior change with the transfer pathway ,

Pierre-Marie Gassin , Marcoule Institute for separative Chemistry , France ,

Gaelle Martin-Gassin , Marcoule Institute for separative Chemistry , France ,

52 SIS2012

Olivier Diat , Marcoule Institute for separative Chemistry , France.

Dynamic interfacial tension of Triton X-100 at water/dodecane interface is investigated using a pendant drop technique in case of non-equilibrated phases in order to get interface depending kinetic datas of the phase transfer rate. Indeed, this surfactant can transfer across this Liquid/Liquid interface, because it is both soluble in organic and aqueous phase[1]. This measurement permits to probe the dynamic molecular oncoming and outcoming at the interface. As a rule, the measured interfacial tension exhibits a steep initial decrease, pass through a minimum and then level off at a value which depends on the initial concentration of surfactant in the drop. The time delay before equilibrium is due to the limitant step of the surfactant transfer which is clearly the crossing over the liquid/liquid interface. The most important observation is that the interfacial tension evolution depends strongly on the phase where the Triton-X100 is initially present. The dynamic is found to be faster when TX-100 switches from dodecane to water compared to the reverse pathway from water to dodecane. In order to get information about limiting factors of the interfacial transfer mechanism, two theoretical models describing the time evolution of the system will be presented and discussed. The first model is based on a diffusion-controlled adsorption/desorption at the liquid/liquid interface[2] whereas the second supposes that the kinetic is controlling by an interfacial chemical adsorption/desorption process. This last model permits to give an estimation of importance of the chemical processes which occurs at the interface in the overall mass transfert rates at the interface. References: [1] Ravera, F.; Ferrari, M.; Liggieri, L. Advances in Colloid and Interface Science 2000, 88 (1-2), 129-177. [2] Liggieri, L.; Ravera, F.; Ferrari, M.; Passerone, A.; Miller, R.,Journal of Colloid and Interface Science 1997, 186 (1), 46-52.

36 ,

Wetting of Contact Line on Textured Hydrophobic Surfaces ,

Ri Li , University of British Columbia , Canada ,

Yanguang Shan , University of Shanghai for Science and Technology , China.

A common method of achieving super-hydrophobicity consists of fabrication of microstructures on surfaces and coating with hydrophobic chemistry. Measurement of static contact angles is used to characterize and compare the hydrophobicity of these surfaces. Our experimental results showed that these contact angles do not agree with Cassie and Wenzel contact angles. Theoretical analysis was carried out to understand the wetting state of water droplets during the contact angle measurement. A few findings were presented in this work. First, the equilibrium contact angle derived based on local minimum energy at contact line is different from that based on the lowest energy of droplet-surface system, unless the droplet-surface contact area has homogeneous wetting state. This indicates that interactions at contact line rather than the total contact area determines contact angle. In other words, the equilibrium wetting state at contact line results from the local balance of the three interfacial surface tensions. Second, for contact line equilibrium, the physical contact between liquid and solid at contact line can be described by Wenzel, Cassie and another intermediate wetting states. Third, a few measured contact angles were found not to match any of the three equilibrium wetting states, for which possible nonequilibrium wetting states were discussed.

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37 ,

Marangoni Driven Spreading on Model Airway Surface Liquid Subphases ,

A. Khanal , Carnegie Mellon University , United States ,

R. Sharma , Carnegie Mellon University , United States ,

R. Kalita , Carnegie Mellon University , United States ,

F. Gao , Carnegie Mellon University , United States ,

E. Peterson , Carnegie Mellon University , United States ,

T. Corcoran , University of Pittsburgh , United States ,

S. Garoff , Carnegie Mellon University , United States ,

T. Przybycien , Carnegie Mellon University , United States ,

R. Tilton , Carnegie Mellon University , United States

Motivated by the potential for surface tension gradient driven flows to move exogenous drug-containing fluids through the lungs, this presentation concerns the spreading of aqueous surfactant solutions over entangled aqueous polymer solutions, including mucin and simpler polyacrylamide solutions, that mimic the physical properties of airway surface liquid. Surfactant solutions contain dyes that not only serve as tracers but also as drug mimics, modeling the use of surfactant formulations as self-dispersing pulmonary drug delivery vehicles. Anionic, cationic and nonionic surfactants are compared in order to determine the potential impact of surfactant-macromolecule binding on the extent of spreading. For all surfactants and subphases examined, Marangoni stresses initiate flow, and convective spreading terminates with the spread solution confined to a well-defined static area. Spreading times are on the order of tens of seconds, considerably shorter than the timescales for diffusion into the subphase bulk or for subphase disentanglement. Spreading occurs as if the aqueous surfactant solution and aqueous subphase were immiscible. The spread drop forms a static lens that exists for ~10 minutes and must satisfy the capillary force balance while its contents slowly diffuse into the subphase. Similar behaviors occur on both polyacrylamide and mucin solutions, for all three types of surfactants, despite the significant difference in chemistry and association properties of these systems. The independence of spreading behaviors on the chemistry of the surfactant and subphase indicates that the spreading process and final solution distributions are controlled by general capillary and hydrodynamic phenomena and not specific interactions among system components. We acknowledge the support of NIH grant 1 R01 HL105470-01A1 and NSF grants CBET-0931057 and DMS-0635983.

38 ,

Autophobing on Liquid Subphases by Surface Transport ,

R. Sharma , Carnegie Mellon University , United States ,

R. Kalita , Carnegie Mellon University , United States ,

E. Peterson , Carnegie Mellon University , United States ,

T. Corcoran , University of Pittsburgh , United States ,

S. Garoff , Carnegie Mellon University , United States ,

54 SIS2012

T. Przybycien , Carnegie Mellon University , United States ,

R. Tilton , Carnegie Mellon University , United States.

Autophobing, a phenomenon in which a drop of pure amphiphilic molecules or a solution of amphiphiles does not completely wet a high energy surface, has been observed on solid surfaces and on liquid subphases. In some cases the drop actually first spreads and then retracts. Considerable research has examined autophobing on solid substrates, but questions remain about the balance of surface tensions in the final state and what molecular structures produce those surface tensions. Autophobing on liquid surphases has been limited to cases where transport through either the vapor phase or the bulk subphase allows amphiphiles to move to the subphase/air interface beyond the drop and drive autophobing. Motivated by research on Marangoni driven spreading of surfactants across liquid films, we have investigated the mechanism of autophobing on liquid subphases when the insolubility and low vapor pressure of the amphiphile make it impossible for bulk transport to cause the autophobing. We have deposited drops of a pure amphiphilic compound (oleic acid) or a surfactant solution (dodecanol in hexadecane) on water or glycerol-water mixture subphases. We measure surface tensions relevant to the spreading, determine if the amphiphiles have moved from the drop onto the subphase, estimate the packing of those molecules, and show that the transport of these molecules out of the drop must be across the subphase/air interface. In all cases, we observe the escape of amphiphilic molecules across the drop contact line and formation of a monolayer, close to collapse, on the subphase outside the drop. The monolayer formation decreases the subphase/air surface tension external to the drop and reverses the sign of the spreading coefficient from positive (before the monolayer forms) to negative, forcing the drop to retract into a lens of an increased contact angle. Measurement of all three surface tensions at the end of spreading of the drop reveals that it is the reduction in the surface tension of the subphase outside the drop that is solely responsible for inhibiting the spreading of the drop and initiating its retraction. We track the simultaneous movement of the drop contact line and the capillary ridge expanding ahead of the drop, produced by the escaping amphiphilic molecules. In addition, we obtain good agreement between the measured area covered by the drop after the spreading event and a model for the shape of a static drop given all the surface tensions, densities, and the drop volume. We acknowledge the support of NIH grant 1 R01 HL105470-01A1 and NSF grants CBET-0931057 and DMS-0635983.

39 ,

Tribological properties of inoc liquids for hard coatings ,

Shinya SASAKI , Tokyo University of Science , Japan ,

Yuriko KONDO , Tokyo University of Science , Japan ,

Tahahiro KOYAMA , Tokyo University of Science , Japan ,

Ryo TSUBOI , Tokyo University of Science , Japan.

Ionic liquid is expected as a new high-performance lubricant because of its low volatility, high-thermal stability and oxidation stability. The ionic liquids, which have halogen elements in molecule structure, show excellent lubricity for metals contrasting it with halogen-free ionic liquids. The formation of metal halide is presumed to lead such an excellent lubricity. However, corrosive damage occurs in a same time on the worn surface under lubrication with halogen containing ionic liquids. It is considered that hydrogen halide is produced by the reaction between the metal halide and the water contained in ionic liquid as a contamination in the atmosphere. In order to prevent such corrosive phenomena, it is required to apply a halogen-free ionic liquid as a lubricant. The lubricity of halogen-free ionic liquid is, however, very inferior compared with halogen-containing ionic liquids. We thought that applying hard coatings to the sliding material was necessary to use the halogen free ion liquid as a lubricant. In this study, we report on the

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lubricity of two halogen-free ion liquids with different anion structure for various hard coatings. Tribological properties of hard coatings, TiN, TiCN, TiAlN, CrN, CVD-DLC, PCD-DLC and H-free-DLC, were evaluated by using a reciprocating sliding tester. Two kinds of halogen-free ionic liquids, [EMIM][DCN] and [BMIM][TCC], were adopted as a lubricant. Table 1 showed the sliding test conditions. There were observed few wear damage on H-free DLC film. The wear scar diameter of steel ball mating H-free DLC film also showed the lowest value. The lubricity of the ionic liquid [EMIM][DCN] was not seen forTiN, TiCn and CrN though was confirmed for DLCs and TiAlN. On the otherhand, the ionic liquid [BMIM][TCC] showed the lubricity for TiN, TiCN and CrN. DLCs and TiAlN showed higher friction coefficients and wear values compaered with those nitride films. The lubricity of two kinds of ionic liquids showed a quite opposite tendancy to the nitride films and the DLC films. It is condsidered that such difference in the lubricity originates in the moleculre strucure of anions.

40 ,

Nano-Friction of Silica Surfaces in Solutions of Various Electrolytes and pH‚ ,

Ko Higashitani , Kyoto University , Japan.

Molecular-scale understandings about the friction between surfaces in solutions are fundamentally important not only from the scientific point of view, but also in the development of the leading-edge technologies for advanced materials, such as the technology needed to achieve the molecular-scale flatness in chemical mechanical polishing (CMP). We have carried out a series of experiments on the friction of silica surfaces in solutions of various electrolytes and pH by using an atomic force microscope (AFM), and have tried to clarify the mechanisms systematically. It was found that the friction characteristics can be classified into four types. In the type A for the surfaces which are plastic and repulsive each other, the friction increases linearly with the load, and it decreases and then becomes constant with the sliding velocity. In the type B for the surfaces which are plastic and attractive each other, the friction increases linearly with the load, and it increases and then decreases with the velocity. In the type C for the surfaces which are elastic and repel each other, the friction increases non-linearly with the load, and it decreases and then becomes constant with the velocity. In the type D for the surfaces which are elastic and attractive each other, the friction increases non-linearly with the load, and it increases and then decreases with the velocity. These macroscopic behaviors are closely related with the nanoscopic structures of silica surfaces, which are altered by the adsorption of electrolytes and the dissolution of silica surface at high pH. The detailed mechanisms will be discussed in the presentation. Acknowledgements This overview is based on the experimental results done by Drs. IU.Vakarelski, CE.McNamee, DC.Donose, E.Taran, H.Shinto and Mr. N.Teramoto

41 ,

Cationic Polymer Surfactant as a self-healing boundary lubrication film on silicon oxide surface ,

Seong H. Kim , Pennsylvania State University , United States.

The boundary film formation and lubrication effects of low-molecular-weight silicone molecules with cationic side groups were studied. Poly-(N,N,N-trimethylamine-3-propylmethylsiloxane-co-dimethylsiloxane) iodide was synthesized and deposited on silicon oxide surfaces to form a bound-and-mobile lubricant film. The effects of the ionically bound layer and mobile multilayers were investigated. Both nano- and macro-scale tribological tests revealed superior lubrication performance of the silicon molecule with cationic side chains over the neutral silicon molecule (which was modeled with polydimethylsiloxane with the same molecule weight). The multilayer films exhibited characteristic topographic features due to ionic interactions within the polymeric film. In the macro-scale, the effects of

56 SIS2012

ionic content, environmental condition, and advantage of the bound layer on self-healing will be discussed to demonstrate the wear resistance and selfhealing capability. The multilayer spreading rates were estimated to be ~10-11 m2/s. In the nanoscale, the results of disjoining pressure and viscosity measurements help understand the lateral spreading of the mobile layer and identify the mobile species. The mobile species are the reduced tertiary amine form of CPL. The hydrophobic but hygroscopic properties of CPL are also investigated with SFG and ATR-IR. The CPL-coated surfaces are hydrophobic which prevents the detrimental effects of humidity on wear of silicon. In addition, the hygroscopic nature of CPL allows humidity to be absorbed into the film, which enhances the self-healing capabilities. By texturing the silicon surface with nanowells, self-healing can be enhanced when the nanowells are filled with CPL. The nanowells serve as CPL reservoirs that are readily available for self-healing within the wear track for faster cycle intervals. However, the nanowells deteriorate the self-healing from surrounding the contact region due to the refilling of the empty nanowells.

42 ,

Effect of Lateral Roughness on the Adsorption of Surfactants ,

Brian Grady , University of Oklahoma , United States.

The effect of lateral roughness on surfactant adsorption is discussed using a quartz crystal microbalance with specially manufactured crystals to measure adsorption. In all cases, surface roughness causes a decrease in the adsorbed amount with the decrease larger for rougher surfaces. Without sonication of the solution prior to addition, dissipation and adsorbed amount show a maximum at the CMC for rougher QCM surfaces. We explain this effect as the solid-liquid analogue of the minimum in surface tension that occurs at the air-liquid interface: impurities that above the CMC are solubilized in micelles will adsorb at the surface (either in admicelles or directly to the surface) when the concentration is below the CMC. Sonication apparently removes these impurities indicating that these materials have relatively low vapor pressures. At higher temperatures, adsorption decreases more or less uniformly for all surface roughness. Recent molecular dynamic simulations on graphite and graphene surfaces confirm that the morphology, and by extension, the adsorbed amount, will depend on lateral dimensions of a flat surface.

43 ,

Softness effect on the wetting behavior of pillar-like patterned PDMS surfaces ,

Yu-Hao Yeh , National Taiwan University , Taiwan ,

Kuan-Hung Cho , National Taiwan University , Taiwan ,

Li-Jen Chen , National Taiwan University , Taiwan.

We have prepared regular pillar-like patterned polydimethylsiloxane (PDMS) surfaces with different softness by mixing PDMS’s prepolymer base and curing agent at different ratios. The dimension of pillars is 3 X 3 micrometer in cross-section with various heights. The advancing/receding contact angles of water droplet on these patterned surfaces are carefully examined. The wetting behavior on the different softness patterned surfaces is quite different, simply because the deformation of the structure. That is, soft pillars under the water droplet would collapse and surface pattern would change dramatically. It is consistently observed the superhydrophobic behavior for the PDMS substrates with the pillar height larger than 3 micrometer and prepared at the mixing ratio of base to curing agent 10:1. In other words, the water droplet on these substrates exhibits Cassie state. It is interesting to find out that the water droplet deposited on these substrates prepared at the mixing ratio of base to curing agent 20:1 would exhibit petal state. We will discuss this transition between Cassie and petal states. Furthermore, the

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optical microscope is applied to observe the impregnating process of water penetrating into the pillars dynamically when a water droplet is deposited on the regular pillar-like patterned soft PDMS substrates. The flow pattern of the impregnating process among pillars is discussed.

44 ,

Van der Waals interactions and the solubilisation of oil in microemulsions ,

Americo Boza Troncoso , University of Toronto , Canada ,

Edgar Acosta , University of Toronto , Canada.

This work introduces two expressions for the calculation of unretarded Van der Waals interactions in geometries that are relevant to oil solubilization in micelles and for determining the interaction among surfactants in micelles. The first integral applies to the interaction between a sphere and a spherical shell that surrounds the sphere. The second integral calculates the interaction between a truncated cone and the rest of a spherical shell that contains the cone. Both expressions were derived using the method of additive summation of Hamaker and the resulting integrals were validated by comparing their prediction to selected physical properties of linear alkanes. The sphere-shell integration was used to predict, with reasonable accuracy, the surface tension of alkanes at room temperature and reproduced the near zero surface tension values that are obtained close to the critical point. The cone-shell integration method in association with the sphere-shell interaction was used to predict the cohesive energy of different alkanes showing close agreement with experimental data.

45 ,

Mixed Micelle Formation between Anionic Gemini Surfactants with Conventional Polyethoxylated Nonionic Surfactants in Brine Solution ,

Soumen Ghosh , Jadavpur University , India.

The micellization of anionic gemini surfactant, 212 and its monomer, SDMA and another anionic gemini surfactant, GA and polyethoxylated nonionic surfactants, C12E5 and C12E8 has been studied tensiometrically in pure and mixed state in aqueous solution of 0.1 M NaCl to determine physico-chemical

properties such as critical micellar concentration (cmc), surface tension at cmc ( cmc), maximum surface Amin).

The theories of Clint, Rosen, Rubingh, Motomura, Maeda and Nagarajan have been applied to investigate the interaction between those surfactants at the interface and in the micellar solution, the composition of the aggregates formed, theoretical cmc in pure and mixed state and structural parameters as proposed by Tanford and Israelachvili. Various thermodynamic parameters (free energy of micellization and interfacial adsorption) have been calculated with the help of regular solution theory and pseudophase model for micellization.

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46 ,

Spreading of volatile droplets containing non-ionic polyoxyethylene alkyl ether (CnEOm) surfactants. Correlative relationships between spreading parameters and properties of surfactants and surfaces ,

Victoria Dutschk , University of Twente, Faculty for Engineering Technology, Engineering Fibrous Smart Materials (EFSM) research group, Enschede , Netherlands ,

Radomir Slavchev , Sofia University, Department of Physical Chemistry, Sofia , Bulgaria.

Dynamic three-phase contact (TPC) angles of aqueous surfactant solutions (CnEOm) were measured in the pre- and micellar concentration ranges on polymer surfaces of different hydrophobicity. A special emphasis was put on possible evaporation effects at ambient humidity that was varied between 40 and 80%. The interpretation of the experimental data and the observed spreading regimes were analysed in the frame of Blake-Haynes model for the TPC line velocity. The analysis is based on the assumption that the droplet keeps its spherical cap shape during wetting and evaporation processes. According to this assumption, from three geometric parameters measured – the droplet volume V, TPC radius r and TPC angle q only two are independent. Similarly, only two of the observed rate processes – evaporation rate (dV/dt), spreading rate (dr/dt) and contact angle change rate (dq/dt) can be independent. The role of relative humidity, surfactant type and concentration as well as substrate surface energy on the spreading velocity dr/dt and the evaporation rate dV/dt is discussed. The interaction between the two processes (spreading and evaporation) is analyzed.

47 ,

Mixed aggregate formation in gemini surfactant / 1,2-dialkyl-sn-glycero-3-phosphoethanolamine systems: Implications for DNA transfection ,

Shawn Wettig , University of Waterloo , Canada ,

Javed Akbar , University of Waterloo , Canada ,

Naser Tavakoli , Isfahan Medical University , Iran ,

Gerrard Marangoni , St. Francis Xavier University , Canada.

An evaluation of the physical interactions between gemini surfactants, DNA and 1,2-dialkyl-sn-glycero-3-phosphoethanolamine helper lipid are presented in this work. Complexation between gemini surfactants and DNA was first investigated using surface tensiometry where the surface tension profiles obtained were found to be consistent with those typically observed for mixed surfactant-polymer systems; that is, there is a synergistic lowering of the surface tension, followed by a first (CAC) and second (CMC) breakpoint in the plot. The surfactant alkyl tail length was observed to exhibit a significant effect on the CAC, thus demonstrating the importance of hydrophobic interactions during complexation between gemini surfactants and DNA. The second study presented is an investigation of the mixing interactions between gemini surfactants and DOPE using Clint’s, Rubingh’s and Motomura’s theories for mixed micellar formation. The mixing interactions between the 16-3-16/16-7-16/16-12-16/16-7NH-16 gemini surfactants and DOPE were observed to be antagonistic, where the strength of antagonism was found to be dependent upon the gemini surfactant spacer group and the solution composition.

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48 ,

pH-responsive self-aggregates of amphiphilic graft copolymers ,

Jong-Duk Kim , KAIST , Korea, Republic Of ,

Chan Woo Park , KAIST , Korea, Republic Of ,

Hee-Man Yang , KAIST , Korea, Republic Of ,

Won-Hee Hong , KAIST , Korea, Republic Of.

The pH-responsive amphiphilic graft copolymers of containing ionizable functional groups respond to change in pH. As drug delivery systems have been developed, delivery therapeutic drugs in a stable manner and selectively releasing them at desired sites have become an increasingly important factor. For this reason, pH responsive polymers have received great interest for smart drug delivery carriers which can release drugs in a controlled manner. In this talk, we will present pH responsive self-aggregates of amphiphilic graft copolymer for the endosomolytic and tumor specific drug delivery carriers. Amphiphilic poly(amino acid)s graft polymers can be prepared by grafting hydrophobic alkyl chains into hydrophilic poly(amino acid)s backbones. Furthermore, the pH-responsive graft polymers were prepared by attaching various ionic molecules on the polymer backbone. In the case of the histidine conjugated graft polymers, self-aggregates showed buffering effects at physiological and endosomal pH. Moreover, the size and zeta-potential of self-aggregates greatly increased at pH 5, because aggregates swelled by the electrostatic repulsion of ionized histidine. And, iron oxide nanoparticles were encapsulated in the polymer micelles with anticancer drug (DOX). The histidine conjugated magnetic micelles demonstrated high T2 relaxivity coefficients and remarkable MR sensitivity. Furthermore, histidine conjugated magnetic micelles showed high anticancer effects due to endosomolytic property. Charge convertible 2,3-dimethylmaleic anhydride (DMMA) conjugated graft polymer has also been demonstrated. Negatively charged DMMA conjugated surface of micelles prevents aggregation with negative blood serums. However, it is detachable at acidic tumor sites and can be converted into positively charged surface. The pH-responsive charge conversion of polymer micelle surface enables the enhanced cellular uptake at tumor site, and the anticancer drug loaded micelles showed significantly improved anticancer effect.

49 ,

Electrokinetic curves normalized to the concentration of surfactant per unit of surface area ,

Marek Kosmulski , Lublin University of Technology , Poland ,

Dawid Podolak , Lublin University of Technology , Poland ,

Edward MƒÖczka , Lublin University of Technology , Poland.

The effect of ionic surfactants on the zeta potential of nanoparticles of metal oxides was studied at various solid-to-liquid ratios in aqueous systems and in nonaqueous solvents. The concentration of surfactant (per unit of volume), which induced a sign reversal depends on the solid-to-liquid ratio. In contrast the concentration of surfactant (per unit of surface area), which induced a sign reversal was rather insensitive to the solid-to-liquid ratio. The electrokinetic curves obtained at various solid-to-liquid ratios plotted against the concentration of surfactant per unit of surface area produced one master curve. A kinetic study indicated that the electrokinetic potential in dispersions containing ionic surfactants and nanoparticles of metal oxides did not change on aging, and fresh dispersions showed similar behavior as those aged for several days before the electrokinetic measurement.

60 SIS2012

50 ,

Tribological Surface Chemistry of Model Lubricant Additive Measured in Ultrahigh Vacuum ,

Wilfred Tysoe , UW-Milwaukee , United States ,

Octavio Furlong , National University of San Luis , Argentina ,

Brendan Miller , UW-Milwaukee , United States.

Additives are generally added to lubricants, which react with the surfaces to form a boundary lubricating film that can lower friction and/or prevent wear. At the high interfacial temperatures that occur under so-called extreme-pressure conditions, the surface reaction and film growth kinetics are dominated by thermal processes. In contrast, it is postulated that, under mild conditions, where the surface temperature rise is low, a surface film can be formed by a shear-induced, surface-to-bulk transport mechanism. This effect is investigated by studying the tribologically induced surface reactions of model sulfur- and boron-containing additives on copper surfaces in ultrahigh vacuum (UHV) where the background pressure is ~1×10-10 Torr. The nature of the initial surface species that are formed by exposure of the copper surface to the model lubricant additive is investigated using a range of surface analytical techniques such as temperature-programmed desorption (TPD), reflection absorption infrared spectroscopy (RAIRS) and X-ray photoelectron spectroscopy (XPS). This enables the nature of the initial surface species to be identified, and their thermal stability to be measured in some detail. The effect of rubbing these adsorbate-covered surfaces is investigated, also in UHV, by measuring the friction coefficient and contact resistance during rubbing. The chemical composition of the wear track is followed using high-spatial-resolution Auger spectroscopy to follow the fate of the surface species caused by rubbing and to test the above postulate. In addition, the effect of low-coordination sites formed on the surface by rubbing on the reactivity of gas phase lubricants is explored and finally, this strategy is used to understand the tribochemistry of borate esters on copper under mild rubbing conditions.

51 ,

Computer simulation of self-assembly of linear and facial surfactant molecules with multiple hydrophilic groups ,

Hans-Jorg Mogel , TU Bergakademie Freiberg Inst. Phys. Chem. , Germany ,

Mirco Wahab , TU Bergakademie Freiberg Inst. Phys. Chem. , Germany ,

Peter Schiller , TU Bergakademie Freiberg Inst. Phys. Chem. , Germany.

Linear and facial surfactant molecules with rigid hydrophobic cores and variously distributed hydrophilic groups of various sizes are investigated for their aggregation properties. Typical linear molecules used in this study are bolaform amphiphiles, which contain two hydrophilic groups terminating a rigid hydrophobic chain. As a second type, gemini amphiphiles, which are rigid bolaamphiphiles incorporating additional short flexible hydrophobic chains at the terminal hydrophilic groups, have been investigated. As models for facial amphiphiles, the biologically important bile salts, consisting of a rigid hydrophobic steroid skeleton and attached hydrophilic groups, have been studied. Using Molecular Dynamics and Monte-Carlo Simulation techniques for studying simple off-lattice coarse-grained models of surfactants, we found a large variety of structures ranging from micelles of varying shape and size to cubic structures and highly ordered linear aggregates. Depending on the temperature and concentration conditions of the surfactant solutions, we observed the occurrence of a diversity of phase structures and the growth of ordered nanostructures. The specific geometrical constraints introduced by the shape and the distribution

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of hydrophobic and hydrophilic groups within the architecture of the single molecules in combination with the rigidity of the backbone allows for the formation of diverse aggregates which even can be chiral. In this study, we have shown that very simple models built from hydrophobic and hydrophilic segments interacting with short range potentials including non-bonded mutually neighboured segments within 1.73 sigma (sigma is the diameter of spherical segments) are adequate to study the molecular aggregation of surfactants by self- assembly. The geometrical frustration between nearest-neighboured segments, arising from the molecular shape, is capable to prevent the formation of common amphiphilic structures such as typically structured micelles and bilayers. The interactions resulting from the non-bonded next-nearest neighbour molecular environment in accordance with the molecular geometry then lead to the various alternative aggregate structures presented here.

52 ,

Effect of different oil loadings on oil-particle-water separation in a falling sphere configuration ,

Sasan Mehrabian , University of Toronto , Canada ,

Edgar Acosta , University of Toronto , Canada ,

Markus Bussmann , University of Toronto , Canada.

The objective of this work is to measure the amount of oil separated from an oil-coated solid sphere and the velocity of the coated sphere in a free fall into a viscous medium as a function of different mass loadings. The fall of the oil-coated sphere was recorded instantaneously by a high speed CCD camera. The velocity of the coated sphere and the mass of the oil separated from the sphere were measured using MATLAB image processing toolbox. This study simulates the recovery of oil from oil sands and the remediation of oil in sand washing process. The breakup of oil from the oil-coated sphere depends upon the shear stress applied to the coated sphere and the physical properties of the oil and viscous fluid in which the sphere falls. The physical properties include the liquid/liquid interfacial tension, liquid/solid surface tension, viscosity ratio of the oil and the viscous medium, and the wetting characteristics. It was determined that below a certain critical oil loading on the particle, the oil did not detach from the particle. At higher oil loadings, droplets of oil detach from the oil film coating the particle. Interestingly, higher oil removal efficiencies were obtained with higher oil loadings.

53 ,

Seeing Surfactant-stabilized Microbubbles by Freeze-fracture Electron Microscopy ,

Brigitte Papahadjopoulos-Sternberg , NanoAnalytical Laboratory , United States ,

Jack Ackrell , NanoAnalytical Laboratory , United States.

Biomedical applications of microbubble suspensions include ultrasound contrast enhancement, ultrasound-promoted drug and gene delivery, and blood substitution. The potency of such microbubbles, used as theranostics, is strongly depending upon their coating material and their morphology adopted in a biological relevant environment. Furthermore, the stability of lung surfactant microbubbles, derived from amniotic fluid, is widely used for the prediction of neonatal respiratory distress syndrome. We studied the morphology of lipid-, polymer, and lung surfactant-stabilized microbubbles by freeze-fracture transmission electron microscopy (ff-TEM). Ff-TEM as a cryofixation replica technique is a powerful tool to visualize microbubbles in a probe-free mode. Since beam-damage resistant replica can be produced from micro-meter size objects also, ff-TEM allows us to study nano-scale events, such as transient structural

62 SIS2012

inhomogeneities in the bubble coating material, in much larger, micro-scale artificial assemblies, such as microbubbles. At a resolution limit of, in our hands, 2 nm for periodical structures we obtained detailed information about the fine structure of bubble coatings. Moreover, the fact that the fracture plane follows the area of weakest forces allows insides into the coating material/gas interface exploring structural inhomogeneities such as domains/rafts in these otherwise inaccessible areas. Freeze-fracture electron micrographs of lipid-stabilized gas-bubbles display concave fracture planes only (shadow in front of the structures). This fracture behavior provides the proof that these microbubbles are coated by a lipid monolayer [1, 2]. Structural inhomogeneities were detected in a certain lipid monolayer type and identified as lipid domains (Ø 100-250nm, step height 20nm) surrounded by a polymer-rich matrix [2, 3]. Cross fractions through polymer-stabilized gas-bubbles reveal a shell thickness of ~300nm stabilizing microbubbles of about 3μm in diameter. Individual polyvinyl alcohol bundles are detectable in the polymer coating [2]. Microbubbles stabilized by a common exogenous lung surfactant, Survanta®, are less than 10μm in diameter and undulation pattern are detected in their monolayer coatings. This lung surfactant is capable of routinely stabilizing approximately a billion microbubbles per milliliter suspension [4]. References: [1]. C. Brancewicz et al., J. Disp. Science and Technology 27 (2006) 761. [2]. B. Papahadjopoulos-Sternberg, Methods in Molecular Biology: Liposomes 606, (2010) Humana Press, 333. [3]. M. A. Borden et al., Langmuir 22 (2006) 4291. [4]. S. Sirsi et al. Soft Matter 5 (2009) 4835.

54 ,

Morphological evolution of depinning drops ,

Ciro Semprebon , MPI-DS , Germany ,

Daniel Herde , MPI-DS , Germany ,

Stephan Herminghaus , MPI-DS , Germany , Martin Brinkmann , MPI-DS , Germany.

The depinning of sessile drops on an inclined plane is a standard method to determine static advancing and static receding contact angles. Despite the apparent simplicity, the onset of motion is a rather complex process. It has been experimentally shown that different deposition protocols induce different relations between drop volume and sliding angle [Pierce, Carmona, Amirfazli: Colloids. Surf A, 2008]. To this end we study the depinning mechanism applying a simple model where the dissipation at the contact line dominates the viscous dissipation in the bulk. This assumption is supported by a recent experimental and numerical work [Carlson, Bellani, Amberg: EPL 2012]. In our approach the liquid-air interface is always in mechanical equilibrium for a given contour of the contact line and it is determined by numerically minimizing the sum of its interface and gravitational energy. In each time step, if the actual contact angle is larger than the static advancing contact angle, the contact line moves proportionally to the difference of the respective cosine. An analogous rule is applied to the receding part of the contact line. We show that the local motion of the leading and trailing edge does not necessarily imply the transition from a pinned to a moving droplet. Contrary to the naive expectation, the depinning force does not always grow monotonically with the magnitude of the contact angle hysteresis. This model can be easily extended to chemically heterogeneous and smoothly corrugated substrates, or globally curved surfaces like spheres or fibers.

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55 ,

Development of a method to probe the surface activity of flavor compounds ,

Amanda Schober , Firmenich Inc. , United States ,

Valery Normand , Firmenich Inc. , United States ,

Anand Subramaniam , Firmenich Inc. , United States.

A model was developed to characterize the efficiency of a surfactant in a practical emulsion (those showing a bi-modal distribution) and applied to experiments using Quillaja saponin to emulsify limonene. Results, using the model, predicted a surface area for the Quillaja saponin which is in accord with published values and reflects a single molecule layer at the interface. Further experiments in which alkanes or limonene-linalool mixtures were emulsified in place of limonene served to demonstrate the ability of the model to discriminate between surface active and non-active flavor compounds. The efficiency of the Quillaja saponin surfactant, as characterized by the model, is clearly enhanced when linalool is present in the emulsion system. This method can thus be utilized as a way to probe the surface activity of compounds to work toward a tool to both predict the success of encapsulating complex flavors and aid in optimizing the surfactant/flavor ratio of the system.

56 ,

Spontaneous Emulsification and Phase Diagrams: Contact between Water and Selected Compositions in the System of Water, Benzene and Ethanol ,

Stig E. Friberg , Ugelstad Laboratory, NTNU , Norway ,

Ayat Bozeya , Hamdi Mango Research Center, University of Jordan , Jordan ,

Abeer Al-Bawab , Hamdi Mango Research Center, University of Jordan , Jordan.

Spontaneous emulsification was early established as a concept in emulsion science1

with the subsequent research focused on interfacial stability

2-5 and diffusion/stranding

2. The direction of research was changed

by Miller and associates6-8

who introduced a straightforward relationship between the diffusion path and spontaneous emulsification; also enabling the prediction of which phase would form the emulsion. Among the applications of spontaneous emulsification the Ouzo effect has become well known; especially through its best known example, pastis investigated by neutron scattering.

9,10 Recently

spontaneous emulsification has been more directly related to phase diagram features.11

The lecture will present the distinctive emulsification effect when water is brought into contact with selected composition in the phase diagram of water, benzene and ethanol, with which it is not in equilibrium. The effect varies, depending on the features of the solubility curve in the system, from complete disintegration of one phase to a slow uptake. Reference: 1.Gad, J. Zur Lehre von der Fettresorption. Arch. Anat. Physiol 1878, p. 181- 192 2.Davies JT, Rideal EK, Interfacial Phenomena. Acad. Press, NY, 1963, Ch 8; 3. Miller CA (1988) Spontaneous emulsification produced by diffusion – A review. Colloid Surf 29: 89-102; 4. Lopez-Montilla JC, Herrera-Morales PE, Pandey S, Shah DO (2002) Spontaneous emulsification: Mechanisms, physicochemical K. aspects, modeling and applications. J Dispersion Sci Technol 23:219-268 5.Salager JL, Forgiarini A, Márquez L, Peña A, Pizzino A, Rodriguez MP, Rondón-González M (2004a), Using emulsion inversion in industrial processes. Advanc Colloid Interface Sci 108-109:259-272) 6. KJ Ruschak and CA Miller, Spontaneous Emulsification in Ternary Systems with Mass Transfer. Ind Eng

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Chem Fundam 11(1972) 534 – 540 7. Miller CA (1988) Spontaneous emulsification produced by diffusion – A review. Colloid Surf 29: 89-102 8. Miller CA, Raney KH (1993) Solubilization-emulsification mechanisms of detergency. Colloids Surf A 27:399-401 9. Grillo I (2003) Small angle neutron scattering study of a world wide known emulsion; Le Pastis. Colloids Surf 225:153-160) 10.Sitnikova NL, Sprik R, Wegdam G, Eiser E (2005) Spontaneously formed trans-anethol/water/alcohol emulsions: mechanism of formation and stability. Langmuir 2:7083-7089) 11. A. Bozeya, A. Al-Bawab, SE Friberg and C.Miller (In press).

57 ,

Preparation and Stability of a Triple Janus Emulsion ,

Hida Hasinovic , Ashland, Inc. , United States ,

Stig E. Friberg , Ugelstad Laboratory, NTNU , Norway.

One of the most important recent developments in emulsion science is introduction of microfluidics technology to prepare dispersed materials of the most complex and exactly defined morphology [1-5]. However, the method has a serious drawback in the restrictions on volume. Even with the combination of channels driven to ultimate numbers[6], the total output is limited to kg/day and the need is evident for a bulk method to prepare multiple emulsions of defined morphology. A first move in this direction has been made by the introduction of triple Janus emulsions of water, a vegetable oil and silicon oil [7-9]. The lecture will present an overview of some factors in the preparation of these emulsions as well as details of the destabilization of one of them. Reference: 1.Nisisako, T., Okushima, S., and Torii, T. (2005) Controlled formation of monodiserse double emulsions in a multi-phase microfluidic system. Soft Matter, 1: 23-27. 2. Chen, H., Shah, R.K., Abate, A.R., and Weitz, D.A. (2009) Janus Particles Templated from Double Emulsion Droplets Generated Using Microfluidics. Langmuir, 25: 4320-4323. 3. Fidalgo, L.M., Whyte, G., Bratton, D., Kaminski, C.F., Abell, C., and Huck, W.T. (2008) From microdroplets to microfluidics: Selective emulsion separation in microfluidic devices. Angewandte Chemie Int. Ed., 47: 2042-2045. 4. Theberge, A., Courtois, F., Schaerli, Y., Fischlechner, M., Abell, C., Hollfelder, F. and Huck, W. (2010) Microdroplets in Microfluidics: An Evolving Platform for Discoveries in Chemistry and Biology. Angewandte Chemie Int. Ed., 49: 5846–5868. 5. Shah, R.K., Shum, H.C., Rowat, A.C., Lee, D., Agresti, J.J., Utada, A.S., Chua, L.- Y., Kim, J.-W., Fernandez-Nieves, A., Martinez, C.J., and Weitz, D.A. (2008) Designer emulsions using microfluidics. Materials Today, 11: 18 -27. 6. Tetradis-Meris, G., Rossetti, D., de Torres, C.P., Cao, R., Lian, G., Janes, R. (2009) Novel Parallel Integration of Microfluidic Device Network for Emulsion Formation. Ind. Eng. Chem. Res., 48: 8881–8889. 7. Hasinovic, H. and Friberg, S.E. (2010) A one-step process to a Janus emulsion. J Colloid Interface Sci., 354: 424-426. 8. Hasinovic, H. and Friberg, S.E. (2011) One-Step Inversion Process to a Janus Emulsion with Two Mutually Insoluble Oils. Langmuir, 27: 6584-6588. 9. Hasinovic, H. and Friberg, S.E. (2011) Destabilization mechanisms in a triple emulsion with Janus drops. J. Colloid Interface Sci., 361: 581-586

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58 ,

Study of sorption behavior of phenol in DODAC vesicular dispersions by means of 1H and PFG-NMR techniques ,

Paolo Sabatino , Ghent University , Belgium.

Phenol has been found as an important contaminant in industrial sites, and solubilization can be used to remove phenol and related compounds by soil washing. This works attempts to investigate the influence of several factors such as concentration, temperature and pH on the sorption behavior of phenol in dicoctadecyl dimethylammonium chloride (DODAC) vesicular dispersions. The study was conducted by means

1H and pulsed field gradient (PFG)-NMR techniques. Chemical shift variation analysis suggested the

presence of cation-π interaction with phenol molecules preferentially located close to the surfactant positively charged head group. Diffusometry experiments have shown that below the surfactant Tm, the sorption is higher in sonicated vesicles due to the incomplete lipid chain freezing caused by the sonication procedure. At higher temperature, when T≈Tm, a maximum in sorption has been found for both sonicated and extruded dispersions. This is a consequence of the increased bilayer disorder that allows the phenol molecules to penetrate more easily into the bilayer. In addition, the influence of the ionization state of phenol was evaluated by using diffusometry experiments combined with the Kärger model. The results indicated that, despite of the higher hydrophilicity of the dissociated form of phenol at high pH, phenol-DODAC interactions were largely favored in basic conditions as a consequence of the strong electrostatic interaction between the negatively charged phenolate ions and the positive charge of the cationic surfactant head group.

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Determination of the enclosed volume of DODAC vesicular dispersions by means of NMR diffusometry and T2 relaxometry ,

Paolo Sabatino , Ghent University , Belgium.

The enclosed volume is an important characteristic of vesicular dispersions. First of all, it determines the encapsulation potential of water-soluble compounds. In addition, the enclosed volume largely determines the dispersed phase volume fraction and, hence, affects the rheology of concentrated vesicular dispersions, as used, for example, in fabric softeners or cosmetics. Low resolution NMR techniques, such as pfg-diffusometry and T2 relaxometry have been proven to be useful to determine the enclosed volume of multilamellar dioctadecyldimethylammonium chloride (DODAC) vesicular dispersions.

The estimation of the enclosed volume with pfg‚ÄìNMR diffusometry method is based on the different diffusion behaviors of water in the external and internal phases. The main advantage of this method is that an external tracer is not necessary. T2 relaxometry, on the other hand, does require the addition of an external paramagnetic probe (MnCl2) to differentiate the relaxation behaviors of water in the two phases.

We show that, when water exchange between the bilayer inner core and the external solution (and viceversa) does not occur, i.e., at low temperature, both the two methods are reliable and resulted in similar values that reflect the real enclosed volume. At higher temperature, however, some discrepancy is noticed, due to the enhanced bilayer permeability of the DODAC vesicles, leading to an underestimation of the enclosed volume. In addition, the T2 relaxometry method has been used to quantify the membrane permeability toward the paramagnetic tracer during long storage and the osmotic shrinkage caused by addition of hyperosmotic paramagnetic solution.

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60 ,

Marangoni trap at a smart liquid surface ,

Subramanyan Namboodiri Varanakkottu , Institute for Nano- and Microfluidics, Center of Smart Interfaces, Petersenstrasse 32, Darmstadt 64287 , Germany ,

Sajan Daniel George , Institute for Nano- and Microfluidics, Center of Smart Interfaces, Petersenstrasse 32, Darmstadt 64287 , Germany ,

Tobias Baier , Institute for Nano- and Microfluidics, Center of Smart Interfaces, Petersenstrasse 32, Darmstadt 64287 , Germany ,

Markus Biesalski , Laboratory for Macromolecular Chemistry and Paper Chemistry,Department of Chemistry, Petersenstrasse 22, 64287 Darmstadt, TU Darmstadt , Germany ,

Steffen Hardt , Institute for Nano- and Microfluidics, Center of Smart Interfaces, Petersenstrasse 32, Darmstadt 64287 , Germany.

The localized change in the surface tension of a liquid surface with an adsorbed surfactant monolayer generates a Marangoni flow from the low surface tension region to the high surface tension region. In this study, we utilize the localized photoinduced switching of the adsorbed surfactant to generate a flow. The photoconversion of the surfactant molecules from the trans isomeric state to the cis isomeric state increases the surface tension and vice versa. The corresponding Marangoni flow enables the trapping of microparticles adsorbed at the liquid-air interface. A schematic representation of the flow pattern and the trapping of particles at the focal spot is shown in Figure 1.

Figure 1. Marangoni flow induced by photoswitchable surfactants. In the present study, a water soluble, nonionic photoswitchable surfactant (C4AzoOC4E2) is used. The photoresponsive azobenzene group is incorporated in the hydrophobic tail of the surfactant. The photoswitching behavior of the surfactant molecules is investigated using UV-VIS absorption spectra measurements. Upon illumination with UV light (325 nm from a He-Cd laser), the absorption peak around 330 nm (a measure of the trans population in the solution) decreases, and the absorption peak around 440 nm (a measure of the cis population) increases. Subsequent irradiation with 442 nm from the laser results in a reversal of the absorption peaks. In order to generate the Marangoni flow, the laser light is focused onto the liquid-air interface. Focusing the 325 nm emission causes a localized increase in surface tension. This results in inward Marangoni flow which is characterized by particle streak velocimetry utilizing microparticles attached to the liquid-air interface. Subsequent irradiation with 442 nm reverses the Marangoni flow and pushes the particles away from the focal point. The inward velocity has a

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characteristic maximum close to the focal spot and decreases farther away from it. The measurements have been carried out at different laser powers. The velocity profile depends upon laser power, with a maximum inward velocity of about 500 μm/s being achieved with a laser power of 5 mW. It is also experimentally confirmed that the trapped particle can be manipulated by moving the laser. The power requirement for trapping the particle is much less than in the case of conventional optical trapping. In conclusion, a novel method of constructing a smart liquid surface is demonstrated. That way the trapping and manipulation of microparticles using hydrodynamic forces becomes possible.

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Biobased oil structure on amphiphilic and tribological properties ,

Girma Biresaw , Bio-Oils Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service , United States ,

Grigor Bantchev , Bio-Oils Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service , United States.

Biobased oils are those derived from farm-based renewable raw materials. Most are vegetable oils (such as soybean, canola, corn, etc) or chemical modifications of vegetable oils. They have a number of interesting structural features that impact their amphiphilic and lubrication properties. The basic chemical structure of biobased oils is a triglyceride, or an ester of a long chain fatty acid and fatty alcohol. Presence of one or more ester groups and two or more long hydrocarbon chains (C12 or higher) in the same molecule, provides amphiphilic character to the molecules. Polarity also provides biobased oils with tribological properties not attainable with petroleum based base oils. Further chemical modification of biobased oils widens the scope of their amphiphilic and tribological properties. This presentation examines the chemical structure of biobased oils and their chemical modifications, and relates it to its amphphilic and tribological properties.

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Capillary pressure and contact line force on a soft solid ,

Jacco Snoeijer , University of Twente , Netherlands ,

Siddhartha Das , University of Alberta , Canada ,

Antonin Marchand , ESPCI Paris , France , Bruno Andreotti , ESPCI Paris , France.

The surface free energy, or surface tension, of a liquid interface gives rise to a pressure jump when the interface is curved. Here we show that a similar capillary pressure arises at the interface of soft solids. We present experimental evidence that immersion of a thin elastomeric wire into a liquid induces a substantial elastic compression due to the solid capillary pressure at the bottom. We quantitatively determine the effective surface tension from the elastic displacement field and find a value comparable to the liquidvapor surface tension. Most importantly, these results also reveal the way the liquid pulls on the solid close to the contact line: the capillary force is not oriented along the liquid-air interface, nor perpendicularly to the solid surface, as previously hypothesized, but towards the interior of the liquid.

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63 ,

Heat induced gel and thermo-coloring phenomena in emulsions of an amidoamine derivative ,

Takeshi Kawai , Tokyo University of Science , Japan ,

Clara Morita , Tokyo University of Science , Japan ,

Yoshiro Imura , Tokyo University of Science , Japan ,

Hiroshi Endo , Tokyo University of Science , Japan.

In recent years thermo-responsive materials have attracted as one of the stimuli-responsive materials for pharmacy, micromachines and pollutant removal. Heat-induced gelation materials, which undergo a thermally reversible transition from a low viscosity solution to a rigid gel upon an increase in temperature, have attracted considerable attention as injectable drug-delivery systems. In this paper, we demonstrate that a long-chain amidoamine derivative (C18AA) acts as a normal organogelator in toluene, exhibiting a phase transition from gel to sol on heating, but changes to a heat-induced gelator upon addition of aqueous LiCl to the toluene gel. Further, we also show the unique multi-layered emulsion of C18AA with an additive of quaternary ammonium salt, tetraoctylammonium bromide (TOAB), which developed the structural color only in the specific temperature region. The amphiphilic compound C18AA, bearing two amide and two terminal amine groups as the hydrophilic portion, was synthesized according to a previous paper. The complex viscosity η*, which obtained from the storage (G’) and loss (G ) moduli for the C18AA toluene gel, decreased gradually from 10-4 Pa•s with increasing temperature, before dropping sharply at above 45 °C upon phase transition from gel to sol. When small amounts of 0.1 M LiCl aqueous solution were added to 1.0 wt% C18AA toluene gel, an opaque water phase was obtained. At higher temperatures, the water phase became rigid, consistent with formation of a gel. Interestingly, this remarkable change in fluidity upon heating and cooling was completely reversible many times. Thus, by simple addition of LiCl, the toluene gel of C18AA could be converted to a heat-induced gel with the opposite thermal property to that of the normal gel. In viscoelastic measurements of the opaque water phase, the η* value was shown to increase drastically from 10-1 to 103 Pa•s. The sol-gel transition was completed over a narrow temperature range of ~ 3 °C. Interestingly, the transition temperatures could be controlled over a wide temperature range of 7-52 °C simply by changing the concentration of C18AA. The gelation mechanism of the heat induced gel is that O/W emulsions of C18AA are trapped and pinned by the network of C18AA aggregates formed in the continuous water phase, leading to a high viscosity for the system. On the other hand, the system of water/C18AA+TOAB/toluene showed phase inversion from O/W to W/O emulsions via the lamellar phase with increasing temperature. In the lamellar phase, the emulsion developed an iridescent color derived from interference of the multilayered liquid crystalline structure. The iridescent color was observed in a limited temperature range, and importantly the coloring temperature and the developed color could be controlled completely independently by adjusting the concentrations of C18AA and TOAB, respectively.

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Tribological Behavior of Polyelectrolyte Brushes with Various Ionic Side Chains in Aqueous Environment ,

Atsushi Takahara , IMCE„ÄÅKyushu University and JST ERATO Takahara Soft Interfaces Project , Japan ,

Motoyasu Kobayashi , JST ERATO Takahara Soft Interfaces Project , Japan.

Biological surfaces show extremely low friction properties supported by water lubrication.[1] For example, Synovial joints, such as hip, knee, shoulder, ankle and finger joints can display friction coefficients in the

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range 0.001-0.03. However, extremely low friction in natural joint systems cannot be achieved by water alone, because the viscosity of water is too low even at high pressure to form useful boundary films.[2] Nature overcomes the disadvantage by biological lubricant additives such as glycoproteins with bottlebrush structure,[3] which have suitable viscoelastic properties in solution and immobilize large amounts of water molecules to aid lubrication.

The authors investigated the environmentally friendly water lubrication by tethering hydrophilic polymers [4] or polyelectrolytes [5-8] on the substrates with sufficiently high grafting density, these have been named 'polymer brushes'. The hydrated brushes in aqueous media form water lubrication layer to reduce friction coefficient without any organic surfactants and oils, which must be useful for artificial joints and guide wire surface coating but also for tidal turbine.

In this study, macroscopic tribological properties of polyelectrolyte brushes prepared by surface-initiated controlled radical polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) and 2-(methacryloyloxy)ethyltrimethyl ammonium chloride (MTAC), and 3-sulfopropyl methacrylate potassium salt (SPMK) from silicon wafer were characterized by ball-on-plate type tribotester in the air, water, and salt solution sliding a glass ball (φ = 10 mm) on the surface at the sliding velocity of 10-5 - 10-1 m⋅s-1 under a loading of 0.49 N at 298 K. The low friction coefficient below 0.02 was observed in polyelectrolyte brushes in 0 - 100 mM of NaCl aqueous solution at the sliding velocity of 10-3 - 10-1 m⋅s-1, however, the friction coefficient increased to be 0.1 in a higher NaCl concentration above 1000 mM for PMTAC and PSPMK brushes. An increase in salt concentration led to the reduction of the electrostatic repulsion interaction among the brushes to result in a higher friction coefficient. On the other hand, the friction coefficient of neutral PMPC brush did not show salt concentration dependence. Friction test of PSPMK brush under a load of 0.49 N in deionized water showed an significantly low friction coefficient around 0.018 continuously even after 450 friction cycles.

References: [1] C. W. McCutchen, Wear 1962, 5, 1. [2] M. Scherge, S. N. Gorb, Biological Micro- and Nano-tribology, Springer: Berlin, 2001. [3] L. Han, D. Dean, C. Ortiz, A. J. Grodzinsky, Biophys. J. 2007, 92, 1384-1398. [4] M. Kobayashi, A. Takahara, Chem. Lett. 2005, 34, 1582-1583. [5] M. Kobayashi, Y. Terayama, N. Hosaka, M. Kaido, A. Suzuki, N. Yamada, N. Torikai, K. Ishihara, A. Takahara, Soft Matter 2007, 3, 740-746. [6] M. Kobayashi, Z. Wang, Y. Matsuda, M. Kaido, A. Suzuki, A. Takahara, Polymer Tribology, Imperial College Press, 2009, pp582-602. [7] M. Kobayashi, A. Takahara, Chem. Record 2010, 10, 208-216. [8] M. Kobayashi, M. Terada, A. Takahara, Faraday Discuss. 2012, 156, in-press (DOI: 10.1039/ c2fd00123c).

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Interaction of two coumarin derivatives within the self-assemblies of surfactants- A steady state and time resolved fluorescence study ,

Aijaz Ahmad Dar , Department of chemistry, University of Kashmir , India.

Cosolubilization of two coumarins viz Warfarin (WF), and Coumarin 30 (C30) in the micellar systems comprising of the nonionic, anionic and cationic surfactants have been studied employing steady state and time resolved fluorescence methods. WF is an anticoagulant and C30 is used in construction of laser medium with applications in optical communications, optical memory materials and sensors. Due to their low aqueous solubility and quenching properties of water for their emission characteristics, such a medium is always avoided. However, aqueous media have been of interest due to the anticipated benefits of reduced thermal gradients for water vs typical organic solvents under lasing conditions and in the biological processes. To this end the solubilization of normally insoluble coumarins in water with the aid of surfactant or cyclodextrin reagents has been studied. , However, there has been scanty reports of WF

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in the micellar medium and needs to be addressed. In addition there is a considerable spectral overlap of emission spectrum of WF with the excitation/absorption spectrum of C30 which makes them suitable for the prospective donor-acceptor pair for the fluorescence resonance energy transfer (FRET) studies. The results shows that WF is solubilized within the CTAB micelles and not in Brij30 or SDS micelles while as C30 gets solubilized in all the three types of micelles. WF quenches the fluorescence intensity of C30 in Brij30 and SDS micelles while enhances in CTAB micelles due to fluorescence resonance energy transfer (FRET) between the pair having efficiency of around 50%. This is new FRET pair workable in the positively charged micelles having prospective importance in the Drug-protein interaction studies since WF is a well know drug which interacts with the serum proteins. The results of the present work suggest the importance of the membrane mimetic organized micellar media type on the cosolubilization of these two coumarin derivatives and their interaction within these nanocontainers.

66 ,

Preparation and Application of Biocompatible Niosomes Containing -sitosterols ,

Asami Aoki , LION Corporation , Japan ,

Takahiro Sagawa , Tokyo University of Science , Japan ,

Taku Ogura , LION Corporation , Japan ,

Kenichi Aburai , Tokyo University of Science , Japan ,

Takeshi Kondo , Tokyo University of Science , Japan ,

Norio Tobori , LION Corporation , Japan ,

Makoto Yuasa , Tokyo University of Science , Japan.

Antioxidant agent and efficient transportation for target position have made rapid strides in recent years. In particular stable drug carrier in vivo has been strongly required for effective drug treatment. We have reported highly activity cationic manganese porphyrin complex, that is manganese [5,10,15,20-tetrakis(4-dimethylthiophenyl)porphyrin] (MnT4Me2SuP) for the beneficial antioxidant effect such as superoxide dismutase (SOD).1) However, only MnT4Me2SuP can not be effective in antioxidation and antitumor because low-molecular weight cause renal excretion. In our study we used -sitosterols instead of cholesterol for the purpose of being the content reduction, and designed novel niosomes having biocompatible and high drug retention in the blood. Then we synthesized MnT4Me2SuP loaded-niosomes containing -sitosterols (MnT4Me2SuP/niosomes, Fig. 1), analyzed the structure, and studied the application as drug carrier.

The MnT4Me2SuP/niosomes solution was obtained by ultrasonic treatment in PBS solution with ion complex composed of MnT4Me2SuP cation and oleic acid anion, -sitosterols and nonionic surfactant such as Tween 60, Span 60 and Brij 72. The difference of the nonionic surfactant is thought to influence on structure, diameter and stability of niosomes. These niosomes were prepared by the addition of -sitosterol : -sitosterol sodium sulfate = 9:1~4:6 as a membrane-stabilizing agent. The diameter is only about 20 nm in the preparation using Tween 60 and Span 60, but the carrier‚Äôs diameter of Brij 72 niosomes are about 140 nm and its stability is more than three days. These results confirmed those the geometry of the membrane properties were in good agreement with that

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of the fluorescence depolarization measurement using 1,6-diphenyl-1,3,5-hexatriene (DPH) probe, the differential scattering calorimetry (DSC) measurement and the small angle x-ray scattering (SAXS) measurement. In addition, we also report to characterize the cancer-fighting property of these niosomes. For example, an alamar blue exclusion asssy of the modified 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method was used to detect the cytotoxicity induced by the MnT4Me2SuP/niosomes. B16 melanomas as cancer was treated with the MnT4Me2SuP/niosomes and mitomycin C (reference material), and 50% inhibitory concentration (IC50) was determined. The cell death increased in a dose-dependent manner. The IC50 of MnT4Me2SuP/niosomes was found to be lower than that of mitomycin C. Anyhow, MnT4Me2SuP/niosomes are found to be useful for drug carrier.

Reference:

1) M. Yuasa, K. Oyaizu, H. Murata, Oleoscience, 6, 307 (2006).

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PalmitateLuciferin: A Molecular Design for the Second Harmonic Generation Study of Ion Complexation at the Air-Water Interface ,

Gaelle Martin-Gassin , Institute for Separative Chemistry of Marcoule , France ,

Pierre-Marie Gassin , Institute for Separative Chemistry of Marcoule , France ,

Diat Olivier , Institute for Separative Chemistry of Marcoule , France.

Solvent extraction is one of the most common and widely used processes to separate and concentrate substances in solution. The phase transfer reaction occurring at the liquid-liquid interface is often facilitated by the formation of complex species using oil-soluble ligands, also called extractants. These extractants have some slight amphiphilic features and the complexation will affect their interfacial properties. Today, it is considered essential to understand the organization of these extracting molecular compounds at the interface both in absence and during the extraction process in order to get a clear molecular picture of the extraction phenomena. Such a study often starts with an initial stage where the complexation reaction is investigated, and this may be performed at the air-water interface, like in the study [1] presented here. A molecular organic chromophore, PalmitateLuciferin, has been synthesized for studying ion complexation at the air-water interface using Second Harmonic Generation (SHG). The SHG technique, with a high surface sensitivity, is one on the most adapted technique to study the active interfacial behavior at the molecular scale. The molecule PalmitateLuciferin, was designed through the addition of a long hydrophobic palmitoyl alkyl chain to the aromatic π- electron system of Luciferin. We first demonstrate that this organic chromophore is a potential candidate for SHG studies of ion complexation with the measurement of its first hyperpolarizability in aqueous solutions by Hyper Rayleigh Scattering (HRS) with and without calcium ions. Then, we characterize the PalmitateLuciferin surfactant properties at the air-water interface combining surface tension measurements with a surface SHG study and Brewster angle imaging. These results allow us to build a molecular description of the chromophore at the interface and observe its molecular re-organization during the monolayer compression leading to the formation of aggregates. Finally, we show that the initial goal of the designing work is achieved since PalmitateLuciferin indeed exhibits a higher SHG response in the presence of calcium ions in the aqueous sub-phase as expected. Reference:

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[1] Martin-Gassin G., Gassin P.-M., Arrachart G., Benichou E., Diat O., Pellet-Rostaing S., Brevet P.F. Molecule Design for Liquid Interfaces Studies by Second Harmonic Generation: the Palmitoylluciferin , Journal of Physical Chemistry C,. DOI: 10.1021/jp2125697

Figure 1: Divalent ions complexation SHG studies using PalmitateLuciferin at the air/water interface

68 ,

Influence of dodecane solubilisation on dynamic surface tension and dilational rheology of Triton X-45 micellar solutions ,

Reinhard Miller , MPI Colloids and Interfaces , Germany.

Long-chain alkanes (or other hydrocarbons) are practically insoluble in water. In the presence of surfactant micelles, alkane molecules can transfer into the hydrophobic core of the micelles (solubilisation), which results in a significant increase of the oil solubility. This process is important in many industrial and biological applications. The maximum bubble pressure method is used to measure the dynamic surface tensions of aqueous micellar TX45 and mixture of SDS/TX45 solutions. The buoyant bubble method with harmonic bubble surface area oscillations is used to study the dilational rheology of the micellar solutions in the frequency range between 0.005 Hz and 0.2 Hz. The data obtained from the adsorption kinetics and rheological experiments of TX45 micellar solutions were analysed using the theoretical approach developed earlier. In particular, the reorientation model of the adsorption layer was employed with parameter values listed in [1], and the diffusion controlled adsorption at the bubble surface was simulated following the lines given in [2]. The influence of the dodecane solubilised by TX45 micelles and by SDS/TX45 mixed micelles on the dynamic surface tension and dilational characteristics of these micellar solutions was also studied. It was shown that the solubilisation of dodecane by micelles leads to the increase of both the dynamic surface tension and the viscoelasticity modulus of the micellar solutions up to the values which are close to those obtained at the CMC without the addition of dodecane. Both effects are explained by the deceleration of the micelle dissolution due to solubilised dodecane. It was found that the theoretical calculations for micellar TX45 solutions agree well with the obtained experimental data. The theoretical models proposed earlier are also shown to be capable for the description of the influence of solubilised dodecane on the dynamic surface tension and viscoelasticity of micellar TX45 solutions. This description is based on the account of the facts that the presence of solubilised dodecane leads to a certain decrease of the TX45 CMC value, and to the approximately twofold decrease of the micelles’ diffusion coefficient caused by the increase of their size. Reference: 1. V.B. Fainerman, S.V. Lylyk, E.V. Aksenenko, A.V. Makievski, J.T. Petkov, J. Yorke, R. Miller, Colloids Surfaces A, 334 (2009) 1-7. 2. V.B. Fainerman, S.V. Lylyk, E.V. Aksenenko, L. Liggieri, A.V. Makievski, J.T. Petkov, J. Yorke, R. Miller, Colloids Surfaces A, 334 (2009) 8–15

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69 ,

Effect of water hardness on surface tension and dilational visco-elasticity of sodium dodecyl sulphate solutions ,


Solutions of sodium dodecyl sulphate (SDS) are widely used in various areas of technology; this implies the extensive studies of surface adsorption and rheological properties of individual SDS solutions and their mixtures with other surfactants, polymers and proteins. In this work, the influence of hardness salts on the adsorption and dilation rheological characteristics of SDS solutions and on the dynamics of the ageing of these solutions is studied. The pendent drop, buoyant bubble profile and maximum bubble pressure methods are used to measure the dynamic surface tension of aqueous SDS solutions in the presence of hardness salts (CaCl2 and MgCl2 in the ratio of 2:1 at concentrations 6 and 40 FH). The surface tension isotherms obtained in the study are compared with our results reported earlier and those obtained by other authors. It is shown that the presence of hardness salts results in an essential increase of the SDS adsorption activity, which indicates the high content of Ca(DS)2 and Mg(DS)2 in the adsorption layers. The surface tension isotherms of SDS in the presence of Ca(DS)2 and Mg(DS)2 are theoretically described by a generalized Frumkin model.

It is shown that the presence of hardness salts results in a significant acceleration of the ageing as compared with comparable additions of NaCl due to a faster hydrolysis and the formation of dodecanol. For prolonged ageing of SDS solutions, the dynamic surface tension curves exhibit a horizontal section which corresponds to the two-dimensional dodecanol condensation. These results are used to estimate the possible concentration of dodecanol in the studied SDS solutions. For these calculations, the theoretical model of adsorption dynamics for two-component solutions proposed earlier in [1] is employed.

The buoyant bubble profile method with harmonic surface oscillations is used to study the dilational rheology of SDS solutions (for 6 and 40 FH) in the frequency range between 0.005 Hz and 0.2 Hz. The visco-elasticity modulus in the presence of hardness salts is found to be higher as compared with its values in the presence of NaCl additions. It is shown that the ageing of SDS solutions leads to an essential increase of the visco-elastic modulus, caused by the respective amount of dodecanol and the presence of the double chain molecules Ca(DS)2 and Mg(DS)2.

Reference: 1. V.B. Fainerman, E.V. Aksenenko, S.V. Lylyk, J.T. Petkov, J. Yorke, R. Miller, Langmuir, 26 (2010) 284–292.

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Trends in biolubricant development ,

Girma Biresaw , Bio-Oils Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, United States Department of Agriculture , United States.

Biolubricants are those formulated from components that are derived from renewable raw materials. This distinguishes biolubricants from the majority of lubricants currently in the global market whose ingredients are derived from petroleum. Biolubricants also are easily biodegradable compared to petroleum based lubricants. Another advantage of biolubricants is that they are safe to people during use, and less hazardous to the environment when disposed after use. In spite of these benefits, the development of biobased lubricants that are competitive in cost and performance to petroleum based lubricants requires overcoming a number of difficult technical and scientific problems. This presentation will highlight some of these problems and the work and progress to overcoming them.

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71 ,

Analytical and CFD Modeling of Drop Imbibition into an Axisymmetric Capillary ,

Poorya Ferdowsi , Mechanical and Industrial Engineering, University of Toronto , Canada ,

Markus Bussmann , Mechanical and Industrial Engineering, University of Toronto , Canada.

Fundamental studies of the behaviour of fluid entering a capillary or pore have widespread application, from understanding the wetting and dewetting of rough and structured surfaces, to applications in micro and nanofluidics, and flow in porous media. Here we present an analysis based on minimization of an interfacial surface energy function to predict equilibrium configurations of a liquid drop atop and within an open axisymmetric capillary. Based on the drop size compared to the hole size, the equilibrium contact angle, and the geometry of the capillary (straight or bevelled), the drop can be totally imbibed by the capillary, or may not wet the capillary at all. We then present an axisymmetric interfacial flow model based on the volume of fluid (VOF) method that predicts simple contact line behaviour even at the capillary edge, that is then applied to the problem of drop imbibition to examine the dynamics of wetting or dewetting of a capillary. The simulations in all cases yield results that approach the equilibrium states predicted by the analytical model, but offer additional insight on contact line motion and interface deformation near the capillary edge.

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Improving performance of the formulation of surfactant-oil-water systems to attain ultralow tension and high solubilization in enhanced oil recovery and other applications: A review of current understanding and prospective future. ,

Jean-Louis Salager , Universidad de Los Andes , Venezuela ,

Ana Forgiarini , Universidad de Los Andes , Venezuela.

Half a century ago, Winsor's pioneering work on phase behavior of surfactant-oil-water systems presented the basics about the effect of the different formulation variables through the R ratio concept. The three phase behavior exhibited when the interfacially adsorbed surfactant molecule presented equal interactions of the with oil and water phases, i.e. when R =1, was considered as a curiosity, until it was associated with a low tension occurrence in 1974. At this moment research and development was intensified to develop surfactant/polymer flooding processes to increase the petroleum recovery much beyond the 25% resulting from the usual secondary techniques. During the next years many applied studies made a diagnostic of the problems and study them from the practical point of view. Systematic studies resulted in a relatively fair understanding of the methods to be used to attain an optimum formulation and in the development of numerical correlations much more accurate and useful in practice than Winsor R ratio, as the surfactant affinity difference concept (SAD). When the crude price went down in the early 1980's, the urgency driving force vanished and only a very few academic and industrial research centers stayed working in the area. However, the early Winsor premises that a better performance (both in low tension or high solubilization) could be attained by increasing the surfactant interaction both with oil and water was perfectly corroborated. At the same time, some fundamental research with simple ternary systems, allowed to improve the understanding of the physical chemistry phenomenology produced at interface, and specially the formation of microemulsion morphology and the bending energy issues in the surfactant film. The research carried out in the 1980-2010 returned information that could be organized as the post Winsor improvement in three stages. The first one consisted in moving the limit resulting from the precipitation of surfactant molecules with extreme increase in size, particularly by using branching, ramification or slight polarity in the tails. The second step was to use surfactant intermolecular mixtures to induce synergy and compactation, even if some

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fractionation lost happens. The third one was to generate intramolecular mixtures with the extended surfactant structure. The use of the three trends together is often a way to improve the performance, but still remain difficult to carry out because of the very high number of alternatives in the formulation. Improving methods is becoming critical in view of the steady increase of the oil price that turns enhanced oil recovery attractive and urgent again. This review shows that combining the SAD generalized formulation with the fundamental understanding of the guidelines to improve the performance, allows to optimize the formulation for a given reservoir in a rational way, with well-targeted experiments.

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Emulsifying, transporting and breaking heavy crude emulsions : A review of recent understanding and prospective future. ,

Jean-Louis Salager , Universidad de Los Andes , Venezuela ,

Johnny Bullon , Universidad de Los Andes , Venezuela.

Heavy crude oils cannot be transported attractively by heating or solvent dilution. Though the emulsified transport is an appealing alternative it implies to combine a sequence of integrated processes, i.e. the emulsion formation, its transport in a pipeline and its breaking at the output.

More than 100,000 Bbls/day of heavy crude emulsion were transported over 200 miles in the orimulsion business in Venezuela during more than a decade. The transport of heavy hydrocarbons in cold temperature regions such as in the peruvian mountains or the canadian plains is a prospective issue. Up to now the reported research and development studies have been concerning mostly the stability and rheology topics dealing with the O/W emulsion pipelining.

However the recent optimization techniques indicate that the three stages have to be integrated because they are obviously not independent. In many cases the original emulsion had been made quite stable to be transported in the pipeline, in particular if pumping stopping for a few days is likely to happen, but then very serious problems had arisen to break it at the end. Optimization thus implies to design the emulsification, stabilization under pipelining and final demulsification, according to the best compromise in the actual conditions, sometimes in presence of conflicting requirements coming from non-independent stages in the process.

The most difficult decision concerns the formulation fine tuning so that it will be adequate everywhere. Since the actual formulation has to be changed to pass from a stable to an unstable emulsion, it is essentially compulsory to do it through a proper temperature variation.

The initial emulsion formation may be produced either down hole or at the well head with a surfactant mixture that insures the O/W morphology that could be stabilized by a cooling. The pipeline transport condition requires the selection of the optimized water-to-oil ratio and the drop size distribution, as well as the emulsion sufficient persistence in case the pumping stops for some time. Finally, the emulsion breakup should be favored by the formulation alteration associated by a change of temperature and by avoiding the formation of a multiple emulsion. As a consequence, this last stage is generally designed in two steps, i.e. first the breaking of the principal O/W emulsion and then, the fully dehydration of the separated heavy crude. On top of it the finally separated water should be made as clean as possible, a requirement that could be taken into account with a two step breaking.

This review will discuss the compulsory and free alternatives in the process concerning the formulation conditions in each stage according to the current know-how.

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74 ,

Mn3O4 Nanorods on Graphene Sheets for High-Power and High-Energy Density Supercapacitor Electrodes ,

Jeong Woo Lee , Korea Advanced Institute of Science and Technology (KAIST) , Korea, Republic Of ,

Jong-Duk Kim , Korea Advanced Institute of Science and Technology (KAIST) , Korea, Republic Of.

Graphene/Mn3O4 composites were prepared by a simple hydrothermal process from KMnO4 using ethylene glycol as a reducing agent. Mn3O4 nanorods of 100 nm‒1 μm length were observed to be well dispersed on graphene sheets. To assess the properties of these materials for use in supercapacitors, cyclic voltammetry and galvanostatic charging-discharging measurements were performed. Graphene/Mn3O¬4 composites could be charged and discharged faster and had higher capacity than free Mn3O4 nanorods. The capacitance of the composites was 100 % retained after 10,000 cycles at a charging rate of 5 A/g.

75 ,

Qualitative and quantitative analysis of CnTAB adsorption layers at the water-oil interface ,

Nenad Mucic , Max Planck Institute of Colloids and Interfaces , Germany ,

Nina Kovalchuk , Institute of Bio-Colloid Chemistry , Ukraine ,

Vincent Pradines , Laboratoire de Chemie de Coordination , France ,

Eugene Aksenenko , Institute of Colloid Chemistry and Chemistry of Water , Ukraine ,

Aliyar Javadi , Max Planck Institute of Colloids and Interfaces , Germany ,

Reinhard Miller , Max Planck Institute of Colloids and Interfaces , Germany.

Qualitative and quantitative analysis of CnTAB adsorption layers at the water-oil interface N. Mucic1, N.M. Kovalchuk1,2, V. Pradines3, E.V. Aksenenko4, A. Javadi1, R. Miller1 1 Max Planck Institute of Colloids and Interfaces, 14424 Potsdam/Golm, Germany 2 Institute of Bio-Colloid Chemistry, 03142 Kiev, Ukraine 3 Laboratoire de Chimie de Coordination, 31077 Toulouse, France 4 Institute of Colloid Chemistry and Chemistry of Water, 252680 Kiev, Ukraine [email protected] Understanding the physical properties of CnTAB adsorption layers requires the analysis of the thermodynamic, kinetic and rheological behaviour. This work reveals the qualitative and quantitative characterization of CnTAB (n = 10, 12, 14 and 16) surfactants at the water/oil interface. The thermodynamic adsorption isotherm, by assuming respective theoretical models gives information about the structure of the adsorption layer. On the other hand, the kinetic and rheological investigations give a clearer picture about the mobility of the adsorption layer, i.e. the diffusion of surfactants to the interface covered by a respective number of molecules (Mucic et al. [1]). The experimental data can be well described with the Langmuir Compressibility and Frumkin Ionic Compressibility models, as shown by Pradines et al. [2]. In the presented experiments we have used hexane as the oil phase. The instruments applied are the Profile Analysis Tensiometer (PAT) for kinetic and rheology investigations and the Oscillating Drop and Bubble Analyzer (ODBA) for short time kinetic investigations. The CnTAB thermodynamics and kinetics are based on the same thermodynamic parameters, while the rheology has different values. The reason for this is that the kinetics is measured immediately after a surface has been freshly formed, therefore, covered by a small number of surfactants at the interface. In contrast to this, the rheology results are obtained after equilibration of the interfacial layer, i.e. when the whole interface is more covered by surfactants. Obviously the initial bulk concentration and competition of molecules for space at the interface are the key factors for the

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difference in the parameters corresponding to adsorption kinetics and the response to perturbations in visco-elasticity experiments. Fig. Left: adsorption of CnTAB surfactants at a freshly prepared water/hexane interface; Right: adsorption of CnTAB surfactants at the water/hexane interface during harmonic oscillations. References: [1] N. Mucic et al., Adv. Colloid Interface Sci, 168, 167 (2011) [2] V. Pradines et al., Colloids Surfaces A, 22, 371 (2010)

76 ,

Passive microrheology : non contact measurement of viscoelastic properties by biopolymers ,

Christelle Tisserand , Formulaction , France ,

Guillermo Smart , Formulaction Inc , United States ,

Mathias Fleury , Formulaction , France.

This work presents a new technique of the passive microrheology for the study of the microstructure properties of soft materials. Our technology uses Multi Speckle DWS (MS-DWS) set-up in backscattering with a video camera. It allows to measure the mean displacement of the microstructure particles in a spatial range between 0,1 and 100 nm and a time scale between 10-3 and 105 seconds. Different parameters can be measured or obtained directly from the Mean Square Displacement (MSD) curve like a fluidity index, an elasticity Index, a Solid Liquid Balance, a Macroscopic Viscosity Index, a relaxation time, a MSD slope… Also when the particles move only thanks to the Brownian motion, the Generalised Stokes Einstein Relation given by Mason and Weitz can be applied to calculate the visco-elastic moduli G’ and G’’ over a large frequency range. This technique allows to monitor the evolution of the microstructure, the restructuration after shearing, the variation of the viscoelastic properties versus temperature, pH, the physical stability of emulsion or suspension... This work focuses on viscoelastic properties evolution and will show application examples and advantages of using a non intrusive method for : - Gelation process of food products in order to measure the speed of the gelation and the final strength of the network (mesh size) - Methylcellose viscoelastic properties evolution versus temperature - Carraghenan networks formation and comparison of their viscoelastic properties versus concentration. References : 1. M. Bellour, M. Skouri, J.-P. Munch, and P. Hébraud, Brownian motion of particles embedded in a solution of giant micelles in The European Physical Journal E, Eur. Phys. J. E 8, 431–436 (2002) 2. M.L. Gardel, M.T. Valentine and D.A. Weitz, 1 Microrheology , Department of Physics and Division of Engineering and Applied Sciences,Harvard University, Cambridge MA 02138 3. T. G. Mason, Estimating the viscoelastic moduli of complex fluids using the generalized Stokes-Einstein equation , in Rheol. Acta (2000) 39: 371-378

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Passive microrheology ; non intrusive measurement of the emulsion stability ,

Guillermo Smart , Formulaction Inc , United States ,

Christelle Tisserand , Formulaction , France ,

Mathias Fleury , Formulaction , France.

78 SIS2012

This work presents a new technique of the passive microrheology for the study of the microstructure properties of soft materials like emulsions. Our technology uses Multi Speckle DWS (MS-DWS) set-up in backscattering with a video camera. It allows to measure the mean displacement of the microstructure particles in a spatial range between 0,1 and 100 nm and a time scale between 10-1 and 105 seconds. Different parameters can be measured or obtained directly from the Mean Square Displacement (MSD) curve like a fluidity index, an elasticity factor, a viscosity factor, a relaxation time, a MSD slope. This technique allows to monitor the evolution of the microstructure, the restructuration after shearing, the variation of the viscoelastic properties versus temperature, pH, the physical stability of emulsion or suspension... This work focuses on the measurement of viscoelastic properties evolution of emulsions to follow their stability. The results will show the advantages of using a non intrusive method to detect nascent destabilisation of the microstructure before rheology or visual method. References : 1. M. Bellour, M. Skouri, J.-P. Munch, and P. Hébraud, Brownian motion of particles embedded in a solution of giant micelles in The European Physical Journal E, Eur. Phys. J. E 8, 431–436 (2002) 2. M.L. Gardel, M.T. Valentine and D.A. Weitz, 1 Microrheology , Department of Physics and Division of Engineering and Applied Sciences,Harvard University, Cambridge MA 02138

78 ,

Monitoring of waters pollution by measurements the bubble velocity variations ,

Marcel Krzan , Jerzy Haber Institute of Catalysis and Surface Chemistry PAS , Poland ,

Paulina Zychowska , Jerzy Haber Institute of Catalysis and Surface Chemistry PAS , Poland ,

Jan Zawala , Jerzy Haber Institute of Catalysis and Surface Chemistry PAS , Poland ,

Kazimierz Malysa , Jerzy Haber Institute of Catalysis and Surface Chemistry PAS , Poland.

Water shortages and pollution of environmental reservoirs is one of urgent problems of our times. There are a lot of different sources of the water contaminations, but most common and potentially hazardous are the organic contaminants of various origins. Typical analytical methods used require rather expensive apparatus and reagents and can be very tedious. Adsorption at liquid/gas interface is a typical feature of surface active substances and presence of adsorption layer affects strongly velocity of the rising bubbles. The bubble velocity diminishes strongly at very low concentrations of different surface active substances [1,2] and can be lowered by over 50% when the liquid-gas interface is fully immobilised. Thus, measurements of lowering of the rising bubble velocity can be used and was proposed as a simple physicochemical method (SPMD) [3] for detection of surface active contaminations (SAC) in waters. The paper presents results of measurements of contaminations of various natural water reservoirs in the Malopolska region of Poland. Velocities of the rising bubbles in the collected water samples were determined and compared to their velocities in clean water and model solutions of commercial detergents of different concentrations. For calibration purposes the dependences of the bubble local and terminal velocities on concentration of typical commercial washing powders ( Persil , Vizir ) and cleaning detergent ( Ludwik ), used in Polish households, were determined. These dependences were used for calculations the degrees of the environmental waters contaminations expressed in term of so called equivalent concentrations of Persil and/or Vizir and/or Ludwik . It was found that the bubble velocity is very sensitive method and the total surface active contaminations of concentration even below 1 ppm can be detected. For example it was found that the contaminants concentration (equivalent Persil concentration) varied from ca. 0.1ppm in sample from Paleczka river (Zembrzyce) to 0.35ppm in sample from Skawa river (Jordanow). The most contaminated, from the water samples studied, were waters of Wisloka River (below Jaslo Refinery), where the contaminants concentration was ca. 1.3ppm. Some of the waters samples studied were also analysed in Malopolska Inspectorate for Environmental Protection

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(MIEP) in Krakow, where the concentrations of anionic surfactants were determined, using classical analytical methods. Figure 1 presents a comparison of the results obtained by our SPMD method to the MIEP results. As seen the total amounts of surface active substances (SPMD method) is significantly higher (3–12 times) than the concentration of anionic surfactants (MIEP results), only. The contaminants concentrations determined by these two completely different and independent methods are of a similar order of magnitude but the concentrations determined by the SPMD method are systematically higher. This seems to be very reasonable because in the SPMD method presence of non-ionic and cationic surfactants is also taken into account.

Figure 1: Comparison of the SPMD and MIEP results.

Reference: 1. K. Malysa, M. Krasowska, M. Krzan, „Influence of surface active substances on bubble motion and collision with various interfaces , Adv. Coll. Int. Sci. 114-115C (2005) 205-225. 2. K. Malysa, J. Zawala, M. Krzan, M. Krasowska, Bubbles Rising in Solutions; Local and Terminal Velocities, Shape Variations and Collisions with Free Surface , chapter 11 in Bubble and Drops Interfaces , ISBN 9789004174955, 2011, pp. 243-292 3. J. Zawala, K. Swiech, K. Malysa, A simple physicochemical method for detection of organic contaminations in water , Coll. Surf. A:, 302 (2007) 293–300

79 ,

Formation of a novel, phase-separated Langmuir film in a binary phospholipid-perfluorinated fatty acid surfactant mixture ,

Matthew Paige , University of Saskatchewan , Canada ,

Ala'a Eftaiha , University of Saskatchewan , Canada.

Perfluorinated surfactants can be used to modulate the structure, dynamics and other physical properties of phospholipid monolayer films at the air-water and solid-air interfaces. This ability to change surface properties of monolayers is useful because of the potential to use this class of compounds to tailor physical-chemical properties of applied surfactant mixtures, including pulmonary lung surfactant mixtures and others. While many phospholipid-perfluorocarbon surfactant pairs are miscible at the air-water interface, not all are, and we have recently developed a phospholipid-perfluorocarbon mixture that is not only immiscible, but forms a highly-structured and unusual monolayer film at both the air-water and solid-air interfaces. In this presentation, we discuss the detailed thermodynamic and structural characterization of this novel film structure through a combination of measurements at the two different interfaces, and compare the results with those of closely-related systems described in the literature.

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80 ,

Controlling adhesion and friction using structured amphiphilic polymer layers: role of conformation and degree of ionization ,

Suzanne Giasson , Universite de Montreal , Canada ,

Benoit Liberelle, Ecole Polytechnique de Montreal , Canada ,

Olga Borozenko , Universite de Montreal , Canada ,

Xavier Banquy , University of California Santa Barbara , United States ,

Ibrahima Ba , Universite de Montreal , Canada.

Experimental surface forces studies of different classes of amphiphilic polymer-bearing surfaces were carried out using the surface forces apparatus and similar molecular techniques in order to elucidate the role of the conformation and degree of dissociation of the molecular chains in controlling friction and adhesion between surfaces. PS-PAA, Plys-PAA, and PtBMA-b-PGMAS were investigated and will be compared with the previoulsy reported behavior of simple surfactants such as didodecyldimethylammonium bromide. We used grafting to and grafting from approaches to covalently attach the macromolecules onto modified mica and silica surfaces with a controlled surface density. Chemical grafting approaches prevent cleavage and/or slipping at the macromolecule/substrate interface. Such molecule detachment, which can occur with non-covalently attached (or physisorbed) polymers and/or surfactants, explains some discrepancies observed between similar studies and the lack of clear understanding of the mechanism underlying polymer/surfactant-mediated lubrication. We investigated the role of electrostatic interactions and molecular conformation on adhesion and friction between amphiphile-coated surfaces without uncertainties in the slip plane. We measured relatively high friction forces between two polymer-bearing surfaces under high pressure and high shear rates, which are not associated with molecule cleavage and/or surface damage, which are frequently observed with physisorbed molecules. Moreover, our results suggest that the role of electrostatic interactions in controlling friction is to control the thickness of the mutual interpenetration zone (between opposing amphiphillic layers) over which friction dissipation occurs. We have also showed that the brush conformation is not solely responsible for the extremely low friction measured between polymer-bearing surfaces. Rather, the fluidity of the hydration layers surrounding the rubbing molecular segments plays an important role in lubricating the interfaces.

81 ,

Response of Microbubbles to Gas Exchange ,

James Kwan , Colorado University - Boulder , United States ,

Mark Borden , Colorado University - Boulder , United States.

Lipid-coated microbubbles are being developed for a variety of biomedical applications in imaging and therapy. In order to better understand microbubble stability and in vivo fate, it is important to elucidate the mechanical properties of the phospholipid monolayer shell. Here, a gas exchange method was used to perturb the monolayer shell of individual microbubbles. The microbubbles were observed to grow and then dissolve back to the initial diameter in a manner that depended on both microbubble size and lipid composition. Following growth and restabilization, shell collapse and stability was also observed. The experimental diameter-time curves during growth and restabilization were analyzed with a gas transport model employing the energy barrier theory for monolayer permeation to account for gas species, acyl-chain length and variable surface pressure. Model analysis allowed computation of apparent surface

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tension as a function of area, which exhibited a characteristic flag-shaped curve comprising three regimes: (i) linear elastic expansion, (ii) nonlinear relaxation during expansion and (iii) linear elastic compression. A comparison of fitted model parameters suggested a molecular mechanism involving expansion, rupture and lipid lateral diffusion in the monolayer shell during growth and lipid domain growth and packing during dissolution. An analysis (in the context of monolayer collapse) of the secondary dissolution phase provided new empirical evidence on the collapse of a microbubble shell. Additionally, we provide evidence that collapse of the microbubble shell can halt, and thus stabilize the microbubble at a distinct size of 1 – 2 µm. We believe this size to be universal for lipid coated microbubbles, and propose three possible mechanisms based on our analysis of microbubble shell collapse and existing theories for lipid monolayer collapse. Overall, these results provide new physical insights into lipid monolayer behavior that are relevant to understanding microbubble stability and medical performance.

82 ,

Effect of Molecular Structure of Self-Assembled Monolayers on Their Tribological Properties ,

Miki Nakano , National Institute of Advanced Industrial Science and Technology (AIST) , Japan ,

Koji Miyake , National Institute of Advanced Industrial Science and Technology (AIST) , Japan.

We investigated the tribological properties of self-assembled monolayers (SAMs) on Au and the effect of structure and end groups of the molecules upon the frictional properties of the modified surfaces of the SAMs. Self-assembling technique is highly expected to be a coating method of organic films, such as lubrication, organic devices and so on, because of the facility of preparation. So far, the tribological properties of such organic thin films like self-assembled monolayers (SAMs) have been investigated to evaluate the tribological properties of molecules. In the present study, we investigated the tribological properties of SAMs on Au using a conventional pin-on-plate method to examine the effects of the end groups and the chain structures of molecules on the friction properties. Preparation of SAMs was as follows. The Au substrates were cleaned by ultraviolet light/ozone treatment and they were soaked in 1 mM organic thiol solution at room temperature for 24 hours. In this study, we used three kinds of organic thiols [HS(CH2)11(OCH2CH2)3OCH3: EG3OMe, CH2(CH2)15SH: HDT, OH(CH2)16SH: HDTOH] which have different end groups of methyl group and hydroxyl group, and different chain structures of alkanethiol chain and origo (ethylene glycol) terminated alkanethiol. The frictional properties of the samples were examined using a home-made pin-on-plate tribometer with a reciprocating motion. A load is 9.8-98 mN and average sliding speeds are 1-10 mm/sec. The mean contact pressure was approximately 53 to 116 MPa. The pin was made of borosilicate glass (Pyrex), with a diameter of 3 mm and a length of 20 mm. The contact angle measurements of pure water showed that the HDT SAM is hydrophobic and the HDTOH SAM is hydrophilic because of the effect of end groups. Although both EG3OMe and HDT SAMs have the same methyl groups as end group, the contact angle of HDT is higher than that of EG3OMe. The reason of lower contact angle of EG3OMe is that the effect of EG unit of EG3OMe. The friction tests showed that the HDT SAM with methyl group as an end group showed slightly lower friction coefficients than the HDTOH SAM with hydroxyl group as an end group. It was reported that the adhesion force between the tips and the SAM surfaces were different between hydrophilic/ hydrophobic surfaces, indicating that the end groups of SAMs affected the friction coefficients. Furthermore, the friction coefficients of EG3OMe SAM were lower than those of HDT SAM. It was considered that the HDT SAM was well-organized structures because of intermolecular interaction of CH2 groups of alkyl chains. On the other hands, the EG3OMe SAM was probably more flexible structures than the HDT SAM because of ethylene glycol units, indicating that the chain structures as well as the end groups affected the friction coefficients of SAMs.

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83 ,

Impact of Mixing on Demulsifier Performance in Oil Sands Froth Treatment ,

Patrick Laplante , University of Alberta , Canada ,

Marcio Machado , University of Alberta , Canada ,

Sujit Bhattacharya , Syncrude Research Center , Canada ,

Samson Ng , Syncrude Research Center , Canada ,

Suzanne Kresta , University of Alberta , Canada.

The effect of different mixing conditions on the performance of demulsifier in oil sands froth treatment is studied in this work. Mixing plays a role in the dispersion of the demulsifier, agglomeration and coalescence phenomena, and possibly in drop break‐up. Partly because of the complexity of the problem, the importance of mixing is not well characterized for oil sands de‐watering process. Oil sands research has sometimes imperfectly characterised mixing parameters and bench scale studies may either undershoot or overshoot the local mixing conditions found at the industrial scale. In addition, poor characterized mixing devices are commonly used at the lab scale ‐ such as magnetic stirrers, jar tests and shaker tables. This study was carried out in two stages using a factional factorial design of experiments. the first stage evaluates the relative effects of bulk demulsifier dosage, local maximum energy dissipation, and mixing time. The second stage of experiments evaluates the relative effects of bulk demulsifier dosage, local maximum energy dissipation, mixing time, and the injection concentration of the demulsifier. Shaker table results did not compare well with results obtained using a stirred tank. A shear and sedimentation test cell (SSTC) was designed to conduct mixing and settling in the same vessel while providing a large ratio of impeller volume to tank volume. The SSTC provided a more uniform intensity of mixing over the volume of the tank, used a much smaller volume of sample (1 L) and allowed the sedimentation of the solids inside the tank.. The bulk concentration of demulsifier is the largest single effect, but favourable levels of local maximum energy dissipation, mixing time, and injection concentration can have an equal effect on the demulsifier performance.

84 ,

Physico-chemical Properties of Gemini Surfactants Containing Ester Bonds ,

Kabir ud-Din , Aligarh Muslim University , India.

In recent years, the demand to design new environmental friendly surfactants to replace conventional ones is receiving much attention. Further, in order to enhance their properties, surfactants in their application mode almost invariably require the presence of additives (thereby requiring smaller amount, which is yet another advantage toward cost reduction). With the above aspects in mind, we have synthesized ester-bonded geminis and studied the effect of inorganic and organic salts on the micelle formation and structural evaluation of micelles through tensiometric, 1H NMR, and flourimetric measurements. KCl, KNO3, KSCN, NaBenz and NaSal were used to probe the principal ionic effects influencing the micellization behavior of biodegradable ester bonded cationic gemini surfactants (ethane-1,2-diylbis(N,N-dimethyl-N-alkylammoniumacetoxy)dichloride, referred to as n-E2-n (CnHn+1(CH3)2N+(CH2COOCH2)2N+(CH3)2CnHn+1.2Cl-, n = 14, 16). By investigating the critical micelle concentration (CMC), free energy of micellization (DGom), free energy of adsorption (DGoads) and aggregation number (Nagg) of the gemini surfactants with the different types of salts, it has become

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possible to describe the effect of counter ions on the micellization behavior. The results, along with SANS and Cryo-TEM data, obtained with the pure surfactants, will be presented and discussed in regard to micellar morphology providing insight in understanding the effect of ions on the delicate balance of forces controlling aggregate morphology and solution properties of charged amphiphilic molecules.

85 ,

Soft Vesicles in the Synthesis of Hard Materials ,

Renhao Dong , Key Laboratory of Colloid and Interface Chemistry, Shandong University , China ,

Jingcheng Hao , Key Laboratory of Colloid and Interface Chemistry, Shandong University , China.

In the solution-phase synthesis of various inorganic or macromolecular materials, templating methods provide a powerful strategy to control the size, morphology, and composition of the resulting micro- and nanostructures. In comparison with hard templates, soft templates are generally constructed using amphiphilic molecules, especially surfactants and amphiphilic polymers. These types of compounds offer advantages including the wide variety of available templates, simple fabrication processes under mild conditions, and easy removal of the templates with less damage to the final structures. Researchers have used many ordered molecular aggregates such as vesicles, micelles, liquid crystals, emulsion droplets, and lipid nanotubes as templates or structure-directing agents to control the synthesis or assembly hard micro- and nanomaterials composed from inorganic compounds or polymers. In addition to their range of sizes and morphologies, vesicles present unique structures that can simultaneously supply different micro-environments for the growth and assembly of hard materials: the inner chamber of vesicles, the outer surface of the vesicles, and the space between bilayers. Two main approaches for applying vesicles in the field of hard materials have been explored: i) in situ synthesis of micro- or nanomaterials within a specific microenvironment by vesicle templating and ii) the assembly or incorporation of guest materials during the formation of vesicles. This talk provides an in-depth look at the research concerning the association of soft vesicles with hard materials by our laboratory and others. We summarize three main principles of soft vesicle usage in the synthesis of hard materials and detailed procedures for vesicle templating and the characterization of the synthetic mechanisms. Using these guiding principles, a variety of inorganic materials have been prepared, such as quantum dots, noble metal nanoparticles, mesoporous structures, and hollow capsules. Polymerization within the vesicle bilayers provides a strategy to enhance vesicle stability, and has been developed to synthesize hollow polymer materials. Since 2004, our group has pursued a completely different strategy in the synthesis of micro- and nanomaterials using vesicles as reactive templates. In this method, the vesicles act not only as templates but also as reactive precursors. Because of the location of metal ions on the bilayer membranes, such reactions are restricted to the interface of the vesicle membrane and solution. Finally, using the perspective of soft matter chemistry, we stress some basic criteria for vesicle templating.

86 ,

Effects of Palmitic Acid - Silica Nanoparticle Complexes on Liquid Interfaces ,

Libero Liggieri , CNR - Istituto per l'Energetica e le Interfasi, Genova , Italy ,

Eduardo Guzman , CNR - Istituto per l'Energetica e le Interfasi, Genova , Italy ,

Michele Ferrari , CNR - Istituto per l'Energetica e le Interfasi, Genova , Italy ,

Eva Santini , CNR - Istituto per l'Energetica e le Interfasi, Genova , Italy ,

Francesca Ravera , CNR - Istituto per l'Energetica e le Interfasi, Genova , Italy.

84 SIS2012

Surfactants are commonly utilised to modify the hydrophilic/hydrophobic character of solid particles in liquid environments. The utilisation of surfactants associated to particles for the modification of the surface properties of liquids is instead a new and little investigated topic that can bring to innovative concepts in relation to several practical applications. We have recently investigated the properties and the structure of different types of interfacial layers obtained from aqueous dispersions of nanometric silica and Palmitic acid (PA) - PA monolayers spread on the silica dispersions, interfacial layers of silica dispersions added with PA, liquid-liquid interfacial layer of silica dispersions and PA solutions in oil – have been investigated. A pool of complementary measurement methods and diagnostics have been used, in order to elucidate the role of the PA interaction with the particles, to investigate the surface-activity of the originated silica-PA complexes and their behaviour at the water-air and water-oil interfaces. A Langmuir trough was used to obtain compression isotherms of the mixed PA+silica surface layers and to measure the dilational viscoelasticity, providing information about the their phase behavior. The structure of these layers was directly investigated by Brewster Angle Microscopy and Ellipsometry. Drop Shape tensiometry was utilized to measure the dynamic surface and the interfacial tension and dilational viscoelasticity of the silica dispersions added by PA. In spite of the different conditions in which the PA and particles were interacting, combining the analysis of above results provided simple interpretations for the variety of observed behaviours, based on the adsorption of PA at the particle surface. In all cases, in fact, a threshold in the PA adsorption at the particles can be identified, above which the resulting nanoparticle-PA complexes abruptly change from hydrophilic to partially hydrophobic, promoting their incorporation into the interfacial layer. The tensiometric studies evidence a large surface-activity of these partially hydrophobic nanoparticle+PA complexes for the aqueous surface, comparable with the most efficient technical surfactant blends. It is remarkable in addition that the above threshold correspond to a very low fraction – about 0.005 - of the PA monolayer saturation. These features can be particularly attractive for practical purposes. On the contrary, the same complexes are only little surface active for the water-oil interface, where they break due to the large oleophilic character of PA, which transfer into the oil phase, while the naked particles return in the dispersion. Acknowledgements: - Italian Institute of Technology (IIT): project SEED 2009 NIPS-Nanoparticle Impact of Pulmonary Surfactant Interfacial Properties . - European Space Agency: (ESA) projects ‘‘FASES-Fundamental and Applied Studies in Emulsion Stability (AO-99-052) and PASTA-Particle Stabilized Emulsions and Foams (AO-2009-0813).

87 ,

Growth of Gold Nanoparticles using Cationic Gemini Surfactants: Effects of Structure Variations in Head and Tail Groups ,

Titoo Jain , Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100, Copenhagen, Denmark , Denmark ,


Kasper Norgaard , Department of Chemical and Biological Engineering, Chalmers University of Technology , Denmark ,

Krister Holmberg , Department of Chemical and Biological Engineering, Chalmers University of Technology , Sweden ,

Kasper Moth-Poulsen , Department of Chemical and Biological Engineering, Chalmers University of Technology , Sweden.

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Anisotropic noble metal nanostructures are of general interest due to their interesting optical and physical properties. Gold nanorods have found application in materials and optics, including polarizers, filters, and to improve the storage density in compact disks. In this study, a library of cationic gemini surfactants is employed to study surfactant directed anisotropic growth of gold nanoparticles. The variables in the chemical structure of these geminis were: (a) the alkyl chain length , (b) the spacer length, (c) the presence of an ester bond in the alkyl tail, and (d) the presence of a hydroxyl group in the spacer. The experiment showed that the anisotropic growth is highly susceptible to small changes in the chemical structure of the surfactant. The yield of rod-shaped gold nanoparticles for the majority of cationic gemini surfactants was above 55% with aspect ratios ranging between 1.5 and 2.5. Using ester-containing surfactants which are susceptible to alkaline hydrolysis is one approach to remove and replace the surfactant with another organic molecule on the surface of gold nanorods for delivery and other medical applications.

89 ,

Settling Properties of Aggregates in Paraffinic Bitumen Froth Treatment ,

Jan Zawala , Natural Resources Canada, Devon , Canada ,

Tadek Dabros , Natural Resources Canada, Devon , Canada.

Paraffinic solvent froth treatment (PSFT) is a relatively new method of bitumen extraction. In contrast to conventional treatment using naphtha solvent, PSFT significantly reduces the level of contamination (water, mineral particles) of bitumen products and also lowers the viscosity of the extracted bitumen through asphaltenes precipitation. During the extraction process, bitumen froth is mixed with paraffinic solvent at the required solvent-to-bitumen ratio (S/B), which results in the formation of aggregates of emulsified water droplets (WD), mineral solid particles (DS), and precipitated asphaltenes (PA). The aggregated contaminants are easy to separate in conventional settlers, which requires less energy than other techniques, including centrifugation. Recently it was found that the temperature of the PSFT process can be an important parameter influencing the efficiency of bitumen extraction. It was observed that, at elevated temperature, the rate of water rejection from the solvent-bitumen froth solution is enhanced and the aggregates formed are larger and tend to settle faster (by more an order of

86 SIS2012

magnitude). This increases the efficiency of the process and the quality of the extracted product. Although operating PSFT at higher temperature significantly improves bitumen extraction, the reasons for the observed aggregate behavior remained unknown. The present paper presents the results of studies on the structural parameters and settling rates of aggregates formed during PSFT at elevated temperature. Suitable amounts of bitumen froth and paraffinic solvent were combined and heated slowly to 80°C in autoclave. Mixing speed and duration were varied. Small samples of diluted froth were collected and diluted according to the dilution procedure elaborated. The structures of the resulting individual aggregates were investigated using light microscopy and the solid content of aggregates was estimated on the basis of image analysis. The settling velocity of the aggregates was measured in situ during autoclave experiments. The settling velocities and dimensions of individual aggregates in a glass column under ambient conditions were measured, as well. It was found that the amount of energy dissipated during the froth treatment process significantly influenced the DS content and the settling rate of the aggregates. Moreover, it was observed that the DS content and settling velocity of aggregates were correlated – higher DS concentration causes higher settling rate. When the amount of energy dissipated was increased proportionally to mixing speed and duration, the concentration of DS in the resulting aggregates increased from 10 wt% to about 65 wt%. Accordingly, the aggregates settling rates increased from about 50 mm/min to above 1000 mm/min, mainly as a result of increased aggregates density. The results of model runs were compared to the corresponding data obtained for real samples collected during semi-industrial PSFT processing. On this basis, it was concluded that aggregates formed at higher temperature have dense structure with negligible porosity and consist only of DS and PA. The high settling rates of the aggregates formed during PSFT at elevated temperature are a consequence of their relatively high densities (~ 2000 kg/m3).

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Comparison between a Monomeric and Gemini Cationic Surfactant for Corrosion Protection of Mild Steel in Sulfamic Acid ,

Milad Motamedi , Institute for Color Science and Technology, Tehran, Iran , Iran ,

Mohammad Mahdavian , Department of Polymer Engineering, Sahand University of Technology, Tabriz, Iran , Iran ,



The surface activity of cationic surfactants ‚ dodecyltrimethylammonium bromide (DTAB) and its gemini counterparts with a spacer containing 4 carbon atoms (12-4-12) ‚ in 1M sulfamic acid were investigated by means of surface tension. Also, their corrosion inhibition activity was measured by means of electrochemical impedance spectroscopy (EIS) during 6h immersion of mild steel specimens in the acid solutions containing mentioned surfactants. Results prove that corrosion inhibition of 12-4-12 is better than DTAB in sulfamic acid solution. It was observed that in various immersion times consist of 20, 80, 140,

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240, 300 and 360 min, with raising of immersion times to 360 min, values of surface coverage (%) and corrosion inhibition (IE%) of both surfactants are increased and reached to its maximum values. In addition, morphology of mild steel samples immersed in test solutions containing 1M sulfamic acid solution (blank solution), sulfamic acid containing 1 mM DTAB and acid solution containing 0.5 mM 12-4-12 was inspected by means of scanning electron microscope (SEM). The cmc of both cationic surfactants in distilled water and 1M sulfamic acid solution was determined by tensiometry. The presence of sulfamic acid has initiated the micellization of both surfactants in much lower concentrations in sulfamic acid compared to distilled water. The cmc value of 12-4-12 is almost 60 times lower than its monomeric counterpart, DTAB, in 1M sulfamic acid solution. The cationic gemini surfactant showed higher surface activity in 1M sulfamic acid solution in comparison to its monomeric counterpart due to the strong tendency of the gemini surfactant to self-assemble and micelle formation at very low concentrations.

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Interactions of hyaluronan with surfactants measured by HR-US ,

Andrea Kargerova , Faculty of Chemistry, BRNO UNIVERSITY OF TECHNOLOGY , Czech Republic ,

Miloslav Pekar , Faculty of Chemistry, BRNO UNIVERSITY OF TECHNOLOGY , Czech Republic.

Hyaluronan is natural biopolymer occurring in the human body and it is used as controlled drug delivery transport system, as a material for scaffold in tissue engineerings. In this work, as a polymeric carriers is used hyaluronan which is soluble in water or physiological solution and has specific receptors for the binding to the right molecules, for application of target delivery. Micelles, on the other hand, offer a core/shell structure, where can be inserted drug. Drug carriers should be stable in vivo for sufficiently long periods of time without provoke any biological reactions. Release of the drug should be started after contact with target tissues/cells and the components of the carrier (surfactant molecules) should be easily removed or biodegradable, in the case of hyaluronan, from the body when the therapeutic function is completed. When we speak about ultrasonic spectroscopy with high resolution (HR-US) we have in mind measurement of velocity that is measured with high resolution. HR-US allows real-time monitoring of molecular transformations without optical markers in transparent and opaque media. This technique is non-destructive, can be used in dilute and concentrated samples, and does not require large sample volumes (minimum 0.03 mL). The work is focused on the study of physico-chemical interactions of hyaluronan with cationic surfactants in the different molecular weight and concentration measured using uncommon technique named High resolution ultrasound spectroscopy. Interactions in these systems are important for the design of systems for targeted delivery, especially of drugs. The experiments was be made in water and sodium chloride solution. First aim was basic study of hyaluronan in dependence on its molecular weight and on elevated temperature (25-50°C) by measuring density and ultrasonic velocity on the densitometer DSA 5000M where we will obtain dependence density and ultrasonic velocity on the temperature (25-50°C) and on the concentration of hyaluronan. Second aim was to determine the critical micelle concentration (CMC) and aggregation concentration (CAC) of the surfactants in the absence and presence of hyaluronan of different molecular weight by method HRUS. The interactions between very low (10 30 kDa), low (about 100 kDa) and high (about 1.5 MDa) molecular weight hyaluronan (produced by Contipro holding, Czech Republic) and cationic surfactants (CTAB hexadecyltrimethylammonium bromide and TTAB tetradecyltrimethylammonium bromide) will be investigated. Cationic surfactants are selected because of the negative hyaluronan charge. Ultrasound velocity and attenuation at 25°C were measured. Critical aggregation concentration of CTAB in water was determined as 1 mmol/kg. Micelles were formed above CMC in water and in the solution with hyaluronan below this concentration there were not any free surfactant and above this concentration micelles were on the chain of hyaluronan.

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92 ,

Development of a new subphase multi-exchange pendant drop tensiometer for in-vitro digestion studies ,

Julia Maldonado-Valderrama , University of Granada , Spain ,

Juan Antonio Holgado-Terriza , University of Granada , Spain ,

Amelia Torcello-Gomez , University of Granada , Spain ,

Miguel Angel Cabrerizo-Vilchez , University of Granada , Spain.

The OCTOPUS is a newly designed Pendant Drop Tensiometer equipped with a subphase multi-exchange device which allows the exchange of the subphase of a pendant drop up to seven times. We have implemented a pendant drop tensiometer, which was fully designed and assembled in the University of Granada which was equipped with a single subphase exchange device where the normal capillary tip is substituted by an arrangement of two coaxial capillaries connected to one of the channels of a micro-injector which can operate independently (Spanish Patent, registration number P9801626)1. Now, we have built up the double capillary technique to achieve a fully automated subphase multi-exchange device by modification of the injection system and the computer program to a 9-vias valve. The OCTOPUS is completely automatic, non-invasive and requires very low amount of material. It is suitable for penetration studies, multilayer formation and automatic CMC measurements. It can be used to create soft interfacial nano-composites such as membranes and polyelectrolyte multilayers, to measure desorption kinetics and reversibility, to test enzymatic treatments on interfacial layers and to build polyelectrolyte assemblies. Also, we have designed an in-vitro digestion model which allows the simulation of the digestion process on interfacial layers. In this work we show the results of in-vitro digestion of protein layers. The conditions of each digestion step or compartment are met by subphase exchange. Then, the interfacial tension is monitored in-situ throughout the whole digestion process and the dilatational properties are measured after the end of each digestion step. This procedure allows investigation the interfacial aspects of protein digestion providing an easy platform to test treatments on the protein with the aim of modifying the digestion pattern. Reference: 1. M. A. Cabrerizo-Vílchez, H. A. Wege, J. A. Holgado-Terriza, A. W. Neumann. 1999. Axisymmetric drop shape analysis as penetration Langmuir balance. Rev. Scientific Instruments, 70, 2438-2444. 2. J. Maldonado-Valderrama, J. A. Holgado Terriza, A. Torcello Gomez, M. A. Cabrerizo Vilchez. Submitted.

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Effect of Salinity on Interfacial Tension of Model and Crude Oil Systems ,

Bikky Kumar , University of Calgary , Canada ,

Elaine Baydak , University of Calgary , Canada ,

Harvey Yarranton , University of Calgary , Canada.

The interfacial tension (IFT) between crude oil and water determines, in part, the height of an oil column in a reservoir. Therefore, it is necessary to estimate the IFT of crude oils and brines when evaluating exploration plays. Crude oils consist of millions of unknown components, some of which may be surface active. It has been observed that the IFT of a hydrocarbon versus brine increases with salt concentration; however, when a small amount of surfactant is present, the IFT can decrease with salinity. Hence, the IFT of crude oil versus brine is a complex function of salinity and surfactant concentration. The objective of this study is to investigate the effect of salinity on the IFT of hydrocarbons with and without added

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surfactants and then to apply the results to crude oil/brine systems. The following data were measured using a drop shape analyzer at ambient conditions: • IFT of pure hydrocarbons, mixtures of pure hydrocarbons, and three crude oils of varying density versus aqueous phases of different salinity. The pure hydrocarbons are toluene, n-heptane, 50 vol. % mixture of n-heptane and toluene (heptol), and cyclohexane. Salt solutions are sodium chloride, calcium chloride and sodium sulphate. Salinities were varied between 0 and 15 wt% in water. • IFT for the same hydrocarbon solutions with the addition of different surface active materials including sodium dodecylsulphate, cetyltrimethylammonium bromide, nonylphenol ethoxylate, Triton X-100, 5β-cholanic acid, and asphaltenes. As expected, the addition of salt increased the IFT for hydrocarbon/water systems. When a non-ionic surfactant was present, the surfactant decreased the IFT but salt addition increased IFT exactly as for the pure hydrocarbon/brine systems. When an ionic surfactant was present at low concentration, salt addition increased the IFT; however, at high surfactant concentration, salt addition decreased the IFT. Naphthenic acids and asphaltenes, which are naturally occurring surfactants found in crude oil, both behaved like weak ionic surfactants.The data were fit with a simple model combining Langmuir adsorption at the interface with the Gibbs isotherm. The effect of an ionic surfactant on the salt depletion near the interface was related to the fractional surface coverage of the surfactant. The application of these results to crude oil/water systems is also discussed.

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Washing diesel contaminated soils with microemulsion-precursor solutions for the removal of aromatics ,

Tereza Neuma Dantas , Federal University of Rio Grande do Norte , Brazil ,

Afonso Dantas Neto , Federal University of Rio Grande do Norte , Brazil ,

Ricardo Lima Leite , Federal University of Semiaride , Brazil ,

Jose Fabricio Melo , Federal University of Rio Grande do Norte , Brazil ,

Catia Rossi , Federal University of Rio Grande do Norte , Brazil.

The pollution of soils caused by refined petroleum products is a widespread recurring environmental problem. Among these petroleum products, diesel fuel, a complex mix of alkanes, naphtenes and aromatics hydrocarbons, is often found in soil matrices as the result of leakage from storage reservoirs and pipelines or accidental spills. The presence of aromatics hydrocarbons are frequently associated with high toxicity levels and ecological impacts observed in soils and groundwaters contaminated by diesel and others fossil fuels. In order to reduce the levels of pollution attributed to diesel contamination of soils and waters, continuous search for efficient treatments has instigated the testing of several groundbreaking technologies. As a result of this search, bioremediation, electro migration, chemical oxidation, vapor stripping, washing processes, among other techniques have been proposed to remediate the problem. Microemulsions, thermodynamically stable mixtures of aqueous and oily phases stabilized with surfactants and, in some instances, co-surfactants, can be employed to improve the lipophilicity of compounds in aqueous medium. This study aims to investigate the use of surfactant and co-surfactant solutions to enhance the solubility of aromatics present in diesel-contaminated soil by microemulsion formation. A central composite design was applied for modeling the removal of aromatics from diesel-contaminated soils. The effect of two variables were investigated, the concentration of surfactants (surfactant and co-surfactant), at range of 0 to 20% (m/m) and temperature, at a range of 28 to 50 oC, both considered as independents variables of the model. Diesel (30 g/kg of soil) was added directly to the sandy soil, constituted of 85% of coarse sand and 15% of medium sand, which was used in the experiments as synthetic contaminated soil. All removal experiments were performed in batch mode. The removal of aromatics from the soil was evaluated by previous extraction with hexane, followed by

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absorbance measurements at 256 nm (aromatic B-band) of the extracts. In the experiment, saponified coconut oil (SCO) and 1-butanol were used as surfactant and co-surfactant respectively. Pseudoternary phase diagrams of water/SCO/1-butanol/diesel systems were constructed at various C/S (co-surfactant/surfactant) ratios. A C/S ratio fixed at 4.0 was found to be the optimum value to obtain a more extensive microemulsion phase domain. A kinetic study showed that the near equilibrium state of removal was attained after 60 minutes of contact time. Approximately 85% of aromatics were removed from soil by water at 28 oC; however, more than 99% removal of these pollutants was reached using a solution with a concentration of 20% in surfactants at 50¬∞C. The experimental results showed that aromatics removal can be fitted by a quadratic model as function of surfactants concentration and temperature. The study also shows that no statistically significant effects of interactions between the variables were observed. Moreover, it was observed that surfactant concentration increase leads to a linear augmentation in aromatics removal, while temperature effects can be explained by the ideal solubility law model. These results corroborate with the fact that enhancement in aromatics removal observed when temperature raises is a result of the improvement, in aqueous solubility, of the lipophilicity of the pollutants and not from a mechanism of augmentation in surfactants micelles size.

95 ,

Hydrophobic Interactions between Polymer Surfaces: Using Polystyrene as a Model System ,

Ali Faghihnejad , University Of Alberta , Canada ,

Hongbo Zeng , University Of Alberta , Canada.

The hydrophobic interaction plays a critical role in a wide range of molecular phenomena in numerous biological and engineering systems. Using a surface forces apparatus (SFA) coupled with a top-view optical microscope, we have directly measured and visualized the interactions between two polystyrene surfaces in different electrolyte solutions (i.e., NaCl, CaCl2, HCl and CH3COOH). We found that the long-range hydrophobic interaction measured is due to bridging of microscopic and sub-microscopic bubbles on polystyrene surfaces. The range of the hydrophobic interaction decreases with increasing the electrolyte concentration for NaCl and CaCl2, but shows no significant change for HCl and CH3COOH, which is related to the formation and stability of bubbles on hydrophobic surfaces due to the ion specificity. The range of the hydrophobic interactions was reduced to about 10-20 nm by degassing the aqueous solutions, but gradually recovered when re-exposing the degassed solution to air. Our results indicate that dissolved gasses in solutions play a crucial role in the hydrophobic interactions of polymer surfaces, and support a three-regime hydrophobic interaction model proposed. Moreover, spontaneous cavitation of water between two interacting polystyrene surfaces was directly observed in degassed aqueous solution at a separation of ≤20 nm. The interfacial energy of polystyrene in various aqueous solutions was determined to be γ=42±5 mJ/m2, close to the values measured in air. Interesting fracture patterns associated with the separation of two hydrophobic polymer surfaces in aqueous solutions were further studied indicating hydrophobic force plays an important role in adhesion-induced fracture of polymer surfaces and thin films. Our study provides new insight into the basic hydrophobic interaction mechanism of polymers and biomacromolecules.

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Microemulsion systems with non-ionic surfactants for the solubilization of petroleum waste ,



Catia Rossi , Federal University of Rio Grande do Norte , Brazil.

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Microemulsion systems (MES) present three or more components (surfactant- S, aqueous phase- AP, oil phase- OP and/or co-surfactant- C). These systems are known for its properties, presenting high thermodynamic stability and high solubility power, which are key elements to applications in various industries such as the food industry, the environmental industry, the petrochemical industry, in soil remediation, and in catalytic cracking. Petroleum waste is an environmental passive that needs to be treated and removed in order to reuse the oil present in its composition. Based on the exposed, this work has the objective of attaining two microemulsioned systems using non-ionic surfactants to be used in the solubilization of petroleum waste from storage tanks. Thereby, a pseudoternary phase diagram was created to the determination of the points within the microemulsioned region (Winsor IV) of the MES1 with Untl L9, isoamyl alcohol, kerosene, and water. MES2 had the same components of MES1 only changing the surfactant by Rnx 11. Following the obtening of the pseudoternary phase diagrams, a specific point was chosen for both systems, with 25% C/S, 5% OP and 30% AP to be applied in the solubilization of petroleum waste studies. Both systems were characterized using the following techniques: density( Mettler-Toledo density meter), viscosity, (Haake-Mars rheometer), particle diameter (Zeta Plus) and surface tension( Kruss tensiometer). The petroleum waste solubilization process applied both microemulsioned systems (MES1 and MES2). The experiment was carried out under constant agitation using the waste: microemulsion ratio of 1:4, with time intervals of 30min and 110min. Following the conclusion of the experiment, the efficiencies of 65 and 78% were observed. And the best results were observed during in the samples that had a longer time of exposure. During the waste solubilization process a dark-colored residue was identified and characterized by fluorescence and X-ray diffraction techniques. Through the analysis of this data it was possible to identify the composition of the residue which was had high levels of inorganic materials, being rich in iron and sulfur, present in the form of Pyrites (FeS2), Mackinawite (FeS) and Magnetite (Fe3O4). The waste composition was determined by the Soxhlet extraction, obtaining the ratios of water (38.7%), organic (44%), and inorganic materials (17.3%). The level of API of the resulting oil, 13%, was determined. Such levels are consistent with the levels found in heavy fractions of petroleum, explaining the precipitation that occurred on the bottom of the storage tank. At last, after the removal of the inorganic materials present in the waste, the oil solubilization efficiency was calculated for the time of 110min, reaching a 90% efficiency level. MES1 presented a 93.45% recovery rate, proving that the action of non-ionic surfactants is an efficient alternative to oil recovery from petroleum waste.

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Chromium extraction from tannery sludge by Winsor II and Winsor III microemulsion systems ,



Keila Melo , Federal University of Rio Grande do Norte , Brazil ,

Maria Moura , Federal University of Rio Grande do Norte , Brazil.

The microemulsion systems have been used to remove heavy metals from industrial wastes (Castro Dantas et al., 2003). In this research chromium extraction from a chromium-rich solution obtained from acid digestion of tannery sludge was investigated by using Winsor II (bi-phase system) and Winsor III (tri-phase) systems. It was used coconut oil soap as surfactant. The tannery sludge was digested by using concentrated nitric acid and hydrogen peroxide, showing 97.5% waste digestion. First, it was obtained the pseudo-ternary phase diagram with all Winsor‚Äôs regions for the system composed by: coconut oil soap as surfactant (S), 1-butanol as co-surfactant (C), kerosene as apolar phase (OP), and chromium aqueous solution as polar phase (AP) ([Cr] = 616 ppm, pH adjusted to 3.7 with 0.01 N NaOH). Two microemulsion extraction methods were evaluated: Method A that uses two-phase systems (Winsor II ‚Äì WII - a microemulsion with water in excess) and Method B that uses three-phase systems (Winsor III ‚Äì WIII - a

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microemulsion with oil and water in excess). To compare the efficiency of chromium extraction, eight systems were chosen: 4 in WII and 4 in WIII. These systems were evaluated considering viscosity, effective droplet size and chromium removal efficiency. All systems showed a Newtonian behavior with viscosity ranging from 3.52 to 4.90 Pa.s. The effective droplet sizes for WII systems (from 6.68 to 15.32 nm) were smaller than for WIII systems (from 24.89 to 52.8nm) due to the bi-continuous micellar structures formed in W III systems. The extraction percentage obtained with the two methods were almost the same, with 99.76 for WII systems and 99.62 for WIII ones. Systems in WIII region were considered to be a more appropriate choice due to the small amount of active mater used (surfactant + cosurfactant), the possibility to recovery the excess oil, and the formation of a chromium-bearing microemulsion in lower volume.

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Physicochemical investigation of mixed reverse micellar systems in biocompatible oils: II. Microstructure by conductance and DLS studies ,

Kaushik Kundu , Indian Statistical Institute, Kolkata , India ,

Bidyut Paul , Indian Statistical Institute, Kolkata , India.

Temperature-induced percolation behavior in mixed reverse micellar systems comprising anionic surfactant, sodium bis(2-ethylhexyl) sulfosuccinate (AOT), and nonionic surfactant, polyoxyethylene(20) sorbitan trioleate (Tween-85) in biocompatible oils of different chemical structures and physical properties [ethyl oleate (EO), isopropyl myristate (IPM) and isopropyl palmitate (IPP)] have been studied at a total surfactant concentration (ST) of 0.25 mol dm-3. The threshold percolation temperature (Tp) of the mixed reverse micellar systems has been found to be dependent on water content (ω), content of nonionic (XTween-85), total surfactant concentration (ST), oil and concentration of added electrolyte (NaCl). The scaling laws for the temperature-induced percolation have been found to be obeyed but the equation parameters (s, t, k and µ) in pre and post-percolation regions differ in magnitude from what theory predicts. The activation energy, Ep has been estimated from Arrhenius plots for the percolation process of AOT-Tween-85 mixed reverse micellar systems. The standard free energy change (ΔG0cl), enthalpy change (ΔH0cl) and entropy change (ΔS0cl) of cluster formation have been evaluated at different physicochemical environments to underline the percolation process in the light of thermodynamics of droplet clustering. The estimated values of ΔG0cl for different compositions have been found to be negative, which indicates spontaneous formation of clusters for these systems. The values of ΔH0cl and ΔS0cl have been found to be positive accounting for a strong heat-absorbing step in the percolation process. The threshold percolation temperature, Tp has been determined for systems as referred above, in presence of additives of different molecular structures, physical parameters and/or interfacial properties. For this purpose acetyl modified amino acids (MAA) viz. N-acetyl-l-glycine (NAG), N-acetyl-l-leucine (NAL), N-acetyl-l-glutamic acid (NAGA) and N-acetyl-l-cysteine (NAC) have been exploited to investigate the effect on the percolation threshold in these mixed surfactant reverse micellar systems. All the additives have shown resisting effect on the percolation threshold value. The effect of MAA on the activation energy (Ep) of these reverse micellar systems have also been accounted. The concentration of additives influences the parameters both Tp and Ep for all investigated systems. A mathematical model has been proposed for the estimation of various structural parameters, that is, aggregation number (Ns), radius of droplet (Re), radius of water pool (Rw), surface number density of surfactant molecules (αs), the effective droplet number per unit volume of solution (Nd) and the interfacial area per surfactant molecules of the mixed reverse micellar systems, water/AOT/Tween-85/IPM. The size of the droplets increases with increase in ω and XTween-85, whereas droplet size decreases with increase in ST. Droplet dimensions have also been measured by dynamic light scattering studies (DLS). An attempt has been made to underline the microstructures of these systems in the light of percolation of conductance vis-à-vis thermodynamics of droplet clustering and structural parameters (evaluated using mathematical models and experimentally determined from DLS measurements).

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99 ,

Effects of Secondary Structures on Adsorption Behavior of Peptides ,

Mojtaba Binazadeh , University of Alberta , Canada , Hongbo Zeng , University of Alberta , Canada ,

Larry Unsworth , University of Alberta , Canada.

Effects of Secondary Structures on Adsorption Behavior of Peptides Mojtaba Binazadeh, Hongbo Zeng*, Larry D. Unsworth* Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, T6G 2G6, Canada Email: [email protected], [email protected] The adsorption of proteins on different solid surfaces has attracted much interest over the past two decades, which is directly related to numerous biomedical and bioengineering applications. Yet, the molecular interaction mechanisms between peptides and solid surfaces during the adsorption process remain limited. Much work is needed to elucidate the fundamentals of solid-binding kinetics of peptides and effects of peptide primary and secondary structures on their adsorption behavior. In this research, secondary structures (a-helix, b-sheet) were induced in Poly L-Lysine (PLL) via modulating solution pH and temperature. Circular Dichroism (CD) measurements confirmed the formation of these secondary structures which are stable for at least 8 hours in solution and persist upon adsorption on gold surfaces. The adsorption of PLL in α-helix and β-sheet conformations from physicochemically identical solution on gold surface was studied using a quartz crystal microbalance with dissipation (QCM-D). The QCM-D measurements revealed: (1) initial adsorption rate for α-helix was higher than β-sheet configuration; (2) the plateau adsorbed amount was ~4.7 times more for β-sheet than α-helix; and (3) the fitted viscosities based on the Voigt viscoelastic model indicate α-helix PLL forms a more rigidly bonded layer on Au. Under same solution conditions, the zeta potential of β-sheet PLL was higher than that of α-helix. Increase of solution ionic strength decreased the zeta potential values of both α-helix and β-sheet PLL, and also generally decreased the final adsorbed amount of peptides. The interaction energies between PLL (in α-helix and β-sheet conformations) and Au were analyzed using the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, which is in good agreement with the experimental results, indicating that the DLVO forces and peptide conformations play critical roles in the adsorption of PLL peptide on solid surfaces.

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Enhanced Gene Delivery through Gemini Surfactant Mediated Transfection of Linear Covalently Closed (lcc) Mini-Plasmids ,

Chi Hong Sum , School of Pharmacy, University of Waterloo , Canada ,

Nafiseh Nafissi , School of Pharmacy, University of Waterloo , Canada ,

Roderick Slavcev , School of Pharmacy, University of Waterloo , Canada ,

Shawn Wettig , School of Pharmacy, University of Waterloo , Canada.

Gene delivery by non-viral transfection vectors confers significant safety advantages over viral vectors as they inhibit immunostimulation and insertional mutagenesis. However, improvements to transfection efficiencies are vital for effective gene delivery suitable for gene therapy. Previous studies have implicated enhanced transfection efficiencies through the employment of novel derivatives of gemini surfactants. The application of an innovative linear covalently closed (lcc) mini-plasmid, in combination with DNA complexation by gemini surfactants, serves to generate effective vectors with enhanced transfection efficiencies. Lcc mini-plasmids are superior to traditional circular covalently closed (ccc) plasmids as they decrease particle size, permit optimal binding interactions with gemini surfactants, and improve

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encapsulation and protection by gemini surfactants. Such advantages, along with the incorporation of four SV40 enhancer elements in each lcc mini-plasmid, have demonstrated heightened transfection efficiencies and transgene expression as indicated by preliminary results from in vitro transfection assays.

101 ,

Synergistic interactions between macromolecules and surfaces provide enhanced lubrication and wear protection ,

Xavier banquy , University of California Santa Barbara , United States ,

Dong-woog Lee , University of California Santa Barbara , United States ,

Saurabh Das , University of California Santa Barbara , United States ,

Jing Yu , University of California Santa Barbara , United States ,

Jacob Israelachvili , University of California Santa Barbara , United States.

Articular joints have been reported to exhibit excellent lubricating and wear resistance properties. In synovial fluid, healthy cartilage surfaces slide on each other with extremely low friction coefficients of 0.0005-0.04 (at least initially), and showing little wear over the lifetime of a person [1]. Water is the major component of the cartilage tissue, composing about 70-80% of the cartilage by weight. In the remaining solid fraction , type II collagen is the most abundant component, constituting 50-80% of the dry weight. The remaining components are hyaluronic acid (HA), glycosolated proteins (known as proteoglycans, GAGs, and lubricin, LUB), and a complex mixture of lipids [2-3]. Different mechanisms have been proposed to explain the exceptional lubrication properties of cartilage. All the mechanisms reported so far do not consider the structure and synergistic interplay of the different components in synovial fluid and the superficial layer of articular joints, which are known to be extremely important under boundary lubrication conditions. Previous studies have focused on identifying the role of isolated components of the synovial fluid like HA, lubricin or even lipids in boundary lubrication. The main conclusion that can be drawn out of these studies is that none of the components studied so far is able to provide by itself good lubrication and/or wear resistance. This finding suggests that synergistic interactions between synovial fluid components and the collagen surfaces play a crucial role in the boundary lubrication and wear resistance mechanisms. During this presentation we will describe two novel lubrication and wear protection mechanisms recently identified that are the result of synergistic interactions between the different components of the synovial fluid and the cartilage matrix. These mechanisms involve the physical crosslinking of HA on the superficial layer of articular cartilage by lubricin (LUB) which provides enhanced wear protection and lubricating properties to the cartilage surface and also the trapping of HA molecules in the cartilage matrix during compression which provides effective boundary lubrication and wear protection to the surfaces.

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Folate-linked light-sensitive liposome incorporating 7-acetoxycoumarin responding to UV-irradiation for cancer therapy ,

Hee Jin Seo , Kangwon National University , Korea, Republic Of ,

Sung Kyeong Hong , Kangwon National University , Korea, Republic Of ,

Hyun Ju Cha , Kangwon National University , Korea, Republic Of ,

Jin-Chul Kim , Kangwon National University , Korea, Republic Of.

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Coumarin and its derivative have been used in the light-sensitive research because of their photo-chemical characteristic. 7-acetoxycoumarin monomer (ATCm) is dimerized by cyclobutane bridge

between coumarins at UV light at =365 nm and 7-acetoxycoumarin dimer (ATCd) is again formed

monomer by a UV light =254nm. An aim of our work is to develop multifunctional liposome that targets folate receptor of human carcinoma of the nasopharynx and release encapsulated drug by UV irradiation. In order to incorporate targetability and light-sensitivity, liposome was composed by light-sensitive lipid and the surface of the liposome was decorated by folate.

In this study, ATCm was derived from 7-hydroxycoumarin. First, 12.5g of 7-hydroxycoumarin, 9.5g sodium acetate and 45ml acetic anhydride were put into a three-neck flask. Three drops of pyridine were added in the mixture solution and heated at 144‚ÑÉ with a reflux for 7hr. After the reaction, mixture solution was cooled at room temperature. ATCm was washed with ice water (1L) and ethanol (1L) and filtrated using a filter paper (Whatman, grade2). After that it was dissolved in ethanol and recrystallized. For preparing ATCd, ATCm was irradiated UV light Œª= 365 nm (400W) for 24hr. It was washed using diethyl ether (1L) and recrystallized using acetic acid. ATCm and ATCd were analyzed by 1H-NMR and FT-IR. In order to conjugate folate to 1,2-distearoyl-sn-gylcero-3-phosphoehanolanime-N-[(polyethylene glycol) 2000]-amine (DSPE-PEG2000-amine), DSPE-PEG2000-amine (50mg), dicyclohexylcarbodiimide (DCC, 16.3mg) and pyridine (0.25ml) were added to the folate (12.5mg) in anhydrous DMSO (1ml) and reacted for 4hr at room temperature. The conjugation of DSPE-PEG2000-folate was confirmed by silica gel TLC method. The pyridine was removed by rotary evaporation. Distilled water (6.25ml) was added to the solution and filtrated for dialysis (M.W.C.O. 1,000). For preparing calcein-loaded multifunctional liposomes, DSPE-PEG2000-folate and egg phosphatidylcholine were dissolved in chloroform in a round bottom flask and the chloroform was evaporated using a rotary evaporator. Then, calcein solution (HEPES buffer 30mM, pH 8.0) was put into the dry lipid film. After hydrated, the multifunctional suspension was sonicated and filtrated using gel filtration. The multifunctional liposomes were characterized as different ratio of egg phosphatidylcholine, DSPE-PEG200-folate and ATCd by dynamic light scattering, transmission electron microscopy and quenching (%). In the release test, the liposome were irradiated by UV light Œª= 365 nm for 3 hr at the optimum ratio of egg phosphatidylcholine/DSPE-PEG200-folate/ATCd and released out calein were quantified by fluorescence measurement. And we evaluated cellular uptake efficiency and folate receptor targetability of the multifunctional liposome by confocal laser scanning microscope. Cytotoxicity of the liposome was determined by MTT(3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay.

When the multifunctional liposome is irradiated by UV light = 254 nm (6W), ATCd is cleaved to ATCm at liposomal membrane. Therethrough, liposomal membrane undergoes mechanical stress and calcein will be released from multifunctional liposome. The folated-linked multifunctional liposomes target cancer cells and deliver anticancer drug.

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Surfactant based self-assembled coatings to minimize protein adsorption at solid/liquid interface ,

Mahmoud F. Bahnasy , Department of Chemistry, University of Alberta , Canada ,

Charles A. Lucy , Department of Chemistry, University of Alberta , Canada.

The tendency of protein to adsorb to solid surfaces in an aqueous environment has its impact in many disciplines such as biology, chemistry, engineering and biomedicine. The main forces which govern adsorption at the solid-liquid interface are hydrophobic and electrostatic interactions between proteins and solid surfaces. Protein adsorption also depends on the chemical and physical characteristic of the solid surface. The hydrophilic negatively charged silica surface makes the electrostatic interaction is the dominant factor for protein adsorption. This is particularly true for the basic proteins. Approaches that minimize the protein adsorption are highly desirable. Two tailed cationic surfactants such as

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dioctadecyldimethylammonium bromide (DODAB) possesses the correct packing factor (i.e., a cylindrical geometry) to form self-assembled semi-permanent bilayer coatings on the silica surface. The DODAB coated surface effectively prevents adsorption of cationic proteins. Herein we show the applicability of the surfactant based coatings to optimize protein separations using capillary electrophoresis (CE). CE is a powerful analytical technique for large biomolecules like proteins. A common challenge is the adsorption of proteins onto the negatively charged surface of fused silica capillaries leading to poor CE separations. Currently, the most common way to minimize this adsorption is to coat the capillary inner surface. The structure of the capillary coating can be tailored according to the degree of resolution required for the separation. Either cationic surfactant alone or mixture of a cationic surfactant with a neutral polymer, poly-oxyethylene (POE), can be used to form the desired capillary coating. The applicability of the developed surfactant coatings as separation media of proteins is illustrated. The coating stability, ease of preparation and efficiency of separations of model proteins are used to assess these coatings.

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The surface tension of polyvinyl alcohol and Triton X-100 mixtures ,

Gulnur Alimbekova , Kazakh National Technical University after K.I.Satpaev , Kazakhstan ,

Saule Aidarova , Kazakh National Technical University after K.I.Satpaev , Kazakhstan ,

Zhanar Ospanova , Al-Faraby Kazakh National University , Kazakhstan ,


Reinhard Miller , Max-Planck Institute of Colloids and Interfaces , Germany.

The study of polymer, surfactants and their complexes attracted the attention of the uniqueness of their colloidal-chemical properties, but the research on their adsorption on various interfaces is not enough. The surface tension of polymers and polycomplexes at the water-air interface allow to obtain information about the features of adsorption, and it is an indirect method for studying the structure of adsorbed layers.

The present work is devoted to study the dynamic characteristics of the surface tension of aqueous solutions of nonionic polymer polyvinyl alcohol (PVA) with molecular weight M = 1 * 10

4 - 2,6*10

4 and its

binary mixtures with a nonionic surfactant - Triton X-100 (ethoxylated octylphenol, the average number of hydroxyethyl groups, n = 10 ECR 2.10

-4 mol / l).

The study of the surface tension of binary mixtures of PVA solution with surfactant proceed to the study of the surface tension of the individual components. The experiments isperformed on the device Profile Analysis Tensiometer PAT-1 (SINTERFACE Technologies, Berlin, Germany) in the laboratory ¬´Interfaces¬ª at the Max-Planck Institute. According to Trapeznikov-Zhigach method relaxation times of binary mixtures of polyvinyl alcohol with Triton X-100 are calculated. It is shown that an increase in the relative concentration of surfactant-polymer relaxation time increases, which is associated with increased concentrations of Triton X-100 in solution and its approximation to the CMC, which corresponds to a saturated monolayer of Triton X-100 on the surface. Also the kinetic parameters of adsorption layers formation of PVA and compositions Triton X-100-PVA at the water/ air interface are calculated.

The obtained values of the constants of surface adsorption layer formation allow to determine that the limiting stage of the binary mixtures adsorption of Triton X-100-PVA - PVA is the diffusion of molecules in the liquid/ gas interface. The values of the synergistic effect of reducing of surface tension, surface activity of the adsorbed layer compositions of Triton X-100 with PVA at the liquid/gas interface are calculated from the surface tension isotherms, suggest that the associates of Triton X-100 - PVA have more than the original substance surface activity. Binary mixtures of nonionic surfactant and polymer in aqueous

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solution, apparently, is due to hydrophobic interactions, stabilized by hydrogen bonds. As a result, the polymer coils can be compacted by increasing their rate of adsorption and surface tension reduction.

105 ,

Probing Interfacial Properties and Surface Forces of Comb-type Polymer Polystyrene-graft-Polyethylene oxide (PS-g-PEO) using a Surface Forces Apparatus ,

Ling Zhang , University of Alberta , Canada ,

Hongbo Zeng , University of Alberta , Canada ,

Qingxia Liu , University of Alberta , Canada.

Using a surface forces apparatus (SFA), we have directly measured the molecular and surface interactions of well-defined comb-type polymer polystyrene-graft-polyethylene oxide (PS-g-PEO). The interaction forces of end-functionalized –OH on PEO side chains were investigated in both symmetric (polymer vs. polymer) and asymmetric (polymer vs. mica) configurations. Long-range repulsive forces were measured between the swollen polymer brushes in aqueous solutions, which were shown to have a steric origin and could be well described using the Alexander-de Gennes model. Contact angle measurement showed the water contact angle on PS-g-PEO surface decreased by over 20 degrees in about one min after the water droplet in contact with the polymer surface, which indicates that the PEO side chains are able to extend into water due to the strong van der Waals forces and hydrogen bonding between hydrophilic PEO side chains and water. The extended PEO side chains act as a swollen brush, leading to the strong steric forces measured by SFA. Atomic force microscope (AFM) was also employed to provide complementary information regarding the surface morphology before and after the polymer was exposed to water. Solution ionic strength showed weak impact for the molecular interactions of the comb-type polymer. Our results provide important insights into the design and development of novel functional polymers and coatings with strong antifouling capabilities, i.e., preventing the non-specific binding of bacteria, cells and proteins with significant engineering and biomedical applications.

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Effect of surfactant chain length on the interfacial properties of polyallylamine hydrochloride/ sodium alkylsulphate mixtures at the water/hexane interface ,

Altynay Sharipova , Kazakh National Technical University after K.I.Satpaev , Kazakhstan ,


Reinhard Miller , Max-Planck Institute of Colloids and Interfaces , Germany.

Mixed solutions of olyelectolytes and oppositely charged surfactants are increasingly used in modern technologies; therefore, their interfacial behaviour is important to know. Previous work has mainly focused on bulk properties of aqueous polyelectrolyte/surfactant solutions and their surface properties, mainly at the water/air interface [1-3]. However, only very few papers were devoted to investigations of such polyelectrolyte/surfactant mixtures at water/oil interface [4-6]. The impact of surfactant chain length on dynamic surface properties of alkyltrimethylammonium bromide/polyacrylic acid solutions were studied in [7, 8] by surface tension and dilational rheology. It was shown that the increase of the surfactant’s hydrocarbon chain length leads to the formation of a more rigid structure of the adsorption layer which is characterized by a higher dilational elasticity. The decrease of the length of surfactant hydrocarbon chain leads to a deceleration of the adsorption layer formation [7]. The present work is

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devoted to the study of interactions in mixed solutions containing a cationic polyelectrolyte and anionic surfactants with different alkyl chain length from C10 to C 16 at the water/hexane interface. Interfacial tension, dilational rheology, zeta potential measurements and dynamic light scattering were used to describe features of polyallylamine hydrochloride (PAH) / sodium alkyl sulphate complexes. It is shown how the interfacial behavior of the polyelectrolyte -surfactant complex depends on the alkyl chain length. Interfacial tension isotherms of the complex of polyelectrolyte with sodium decylsulphate, dodecylsulphate and tetradecyl sulphate are shifted to the lower concentrations in comparison with the corresponding pure surfactants. The PAH/sodium decylsulphate, PAH/dodecylsulphate complexes are formed through electrostatic interactions which lead to a significant hydrophobicity of the complexes and the reduction of electrostatic free energy of polyions. For PAH/sodium tetradecylsulphate complex, electrostatic interactions prevail in low surfactant concentrations while with increasing surfactant concentration also hydrophobic interactions come into play. In the studied concentration range PAH/sodium hexadecylsulphate complex are formed through hydrophobic interactions which increases the hydrophilicity and increasing of hydrodynamic radius of the complex. This is supported by zeta-potential, dynamic light scattering and dilational rheology measurements. References: 1. K. Tonigold, I. Varga, T. Nylander, R.A. Campbell, Langmuir, 25 (2009) 4036-4046. 2. J. Penfold, I. Tucker, R.K. Thomas, J. Zhang, Langmuir, 21 (2005) 10061–10073. 3. R. Meszaros, L. Thompson, M. Bos, I. Varga, T. Gilanyi, Langmuir, 19 (2003) 609–615. 4. A.Sharipova, S. Aidarova, N. Mucic, R. Miller, Colloids and Surfaces A: Physicochemical and Engineering Aspects Vol.391 (2011) 130-134 5. Hong-Bo Fang, Colloid. Polym. Sci., 287 (2009) 1131–1137. 6. A.Sharipova, S.Aidarova, V.B.Fainerman, A.Stocco, P.Cernoch, R.Miller, Colloids and Surfaces A: Physicochemical and Engineering Aspects Vol.391 (2011) 112-118 7. A.G. Bykov, Shi-Yow Lin, G. Loglio, V.V. Lyadinskaya, R. Miller, B.A. Noskov, Colloids and Surfaces A: Physicochem. Eng. Aspects 354 (2010) 382–389 8. J. Penfold, I. Tucker, R. K. Thomas,D. J. F. Taylor, Langmuir 23 (2007) 3128-3136

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Influence of Additives in the Properties of a Microemulsion System and its Application in Enhanced Oil Recovery ,



Catia Rossi , Federal University of Rio Grande do Norte , Brazil ,

Ewerton Teixeira , Federal University of Rio Grande do Norte , Brazil ,

Yuri Santos , Federal University of Rio Grande do Norte , Brazil.

In this research it was evaluated the influence of additives (monomer a; polymer b) in surface tension and viscosity of a microemulsion system (MES) and its application in Enhanced Oil Recovery (EOR). The MES was composed by: Renex NP95 as surfactant (S), a blend of n-butanol + 5 wt.% of a hydrotrope as co-surfactant (C), kerosene as oil phase (OP), and distilled water as aqueous phase (AP). First, it was obtained the pseudoternary phase diagram. Three points with increasing percent by mass of active matter (co-surfactanrt/surfactant – C/S) were selected inside the microemulsion area (Winsor IV): Point 1 - 25 wt.% C/S, 75 wt.% AP, 2 wt.% OP; Point 2 - 30 wt.% C/S, 68 wt.% AP, 2 wt.% OP; Point 3 - 35 wt.% C/S, 63 wt.% AP, 2 wt.% OP. The additives a and b were inserted in these microemulsion points in varied concentrations (0.1 and 0.5 %) to evaluate its influence in surface tension and viscosity. The obtained

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results are shown in Table 1.

According to the results, it can be observed that the surface tension is reduced as the active matter in the system is increased. For systems with additive a, the reduction in surface tension with increasing C/S in the system was more significant, as compared with systems without additive (MES). It can also be observed that this reduction was enhanced with increasing amount of additive in the systems. For systems with additive b, a light increase in surface tension with 0.1% was observed as compared with MES and the same behavior with increasing C/S was observed, with 0.5 % there was an important increase in the surface tension of the system. For viscosity, it can be observed an increase in the values with increasing C/S percentile. It can also be observed, as compared with values for MES, that additive a decreased the viscosity of the systems and additive b increased it, in special when 0.5% of b was added. The microemulsion systems, with and without additives, were tested in EOR in a reservoir simulator, showing good results.

109 ,

Concentric drops studies for a quantitative analysis of stabilizing effects of emulsifiers in multiple emulsions ,

Juergen Kraegel , MPI Colloids and Interfaces , Germany ,


Multiple emulsions find different applications in industrial products, for example in food systems to improve sensory characteristics, taste masking, encapsulation of vitamins or in low calorie products. Multiple emulsions can be named as emulsions in an emulsion. To stabilize the different interfaces specific different emulsifiers are used (see a in Fig.1). In general the stability of multiple emulsions is low and poorly controllable, and therefore is a main problem with regard to the production and to the shelf life of a product. The stability of emulsions is controlled by very complex processes at the interface including mass transfer across the interfaces. Multiple emulsions contain more interfaces and are even more thermodynamically unstable than single emulsions. In addition they are very sensitive against shear forces.

The aim of the contribution is to present investigations with concentric drops produced by a special capillary system to analyse quantitatively the distribution of emulsifiers (see Fig. 1b). The capillary pressure technique is used to form concentric drops in a controlled manner. The technique is commonly in use for measurements of dynamic interfacial tension of small spherical single droplets. Two of such devices are used in an adapted version to form drop in drop systems as a model for multiple emulsions. To optimize the production of multiple emulsions information is important about the influence of the

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technological conditions on the stability of the internal phase, the transfer of matter within the complex systems, effective emulsifier systems and the distribution of emulsifiers in the system. A major role in these processes plays the adsorption behaviour of the emulsifiers. In the framework of the present studies model systems are investigated to understand the importance of the properties of the two different thin interfacial films for the overall multiple emulsion formation and stability. Another topic is how it is possible to influence the surfactant adsorption by a co‐adsorption of lipids or biopolymers to produce a kind of barrier function within the interfacial layer to influence the transfer of matter in order to improve the stability. Therefore the investigations focus mainly on the coalescence behaviour of W1/O/W2 double emulsions. Especially the coalescence processes of W1 droplets at the O/W2 interface are studied under material specific (e.g. used emulsifier) and technological specific (kind of flow regime) conditions which are closed to the production conditions of W1/O/W2 double emulsions

Fig.1: a.) Scheme of possible interactions between different surfactants in a W1/O/W2 double emulsion; b.) Example of a concentric drop of an oil/water/oil system

110 ,

Mixed Protein-Surfactant Adsorption Layers Formed in a Sequential and Simultaneous Way at the Water/Air and Water/Oil Interfaces ,

Juergen Kraegel , MPI Colloids and Interfaces , Germany ,


Protein‐surfactant interaction is an important topic of research in modern interfacial and biophysical science. The topic has direct relevance to various fields, such as pharmaceutics, cosmetics, food processing. Such interactions can influence the unfolding of proteins during their denaturation process. The complexes formed raise fundamental questions about the process mechanism that still remains to be fully understood. The interaction features are considered to be the combined manifestations of electrostatic and hydrophobic forces. It generally it depends on the nature of protein and surfactant. Mixed protein‐surfactant adsorption layers can be built up in two different ways. The classical way is when all components adsorb simultaneously from a mixed solution. Alternatively, the components adsorb one after another, i.e. in a sequential way. In the present work, the adsorption of the random coil protein

(W/A) and water/hexane (W/H) interfaces. The used experimental technique is a drop profile analysis tensiometer PAT‐1 especially equipped with a coaxial double capillary for drop volume exchange during the experiments. There are remarkable differences in the behavior of mixed adsorption layers for the two ways of protein‐surfactant complex formation, which are either formed in the bulk in case of simultaneous adsorption or in the surface layer in case of sequential adsorption. The dynamics of desorption of the mixed layers into the bulk solution induced by a washing off with a pure surfactant solution also deviate significantly, which is explained by the different nature and structure of the

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complexes. Compared to the W/A interface, at the W/H interface there is a different conformation of the preadsorbed protein molecules that allows to penetrate more into the oil phase. This favors obviously the interaction with the incoming surfactants, and stabilizes the complexes adsorbed at the interface. Whereas, in the competitive adsorption, the surfactants due to their higher affinity to the W/H interface, adsorb strongly at the interface in competition with the complexes formed already in the bulk. This leads to an increasing presence of freely adsorbed surfactant molecules at the interface, however, only at higher SDS concentrations.

111 ,

O/W suspo-emulsions containing technical surfactants as models of industrial oily wastewater ,

Simona Schwarz , Leibniz Institute of Polymer Research Dresden , Germany ,

Rosana Rojas , Leibniz Institute of Polymer Research Dresden , Germany ,

Sandra Schutze , Leibniz Institute of Polymer Research Dresden , Germany ,

Jorg Bohrisch , Fraunhofer Institut fur Angewandte Polymerforschung , Germany.

Wastewater in the oil recovery industry is usually an intricate system containing oil, water surfactants, as well as different kinds of solid inorganic particles. The treatment of oily wastewater is improving in order to reduce oil losses, to reuse water and protect the environment. Thus, the break-up of such emulsions is one of the major concerns for economic and environmental reasons. The objective of this study is to develop kerosene-in-water emulsions containing solid particles as well as pure and technical surfactants, respectively, able to serve as model wastewater systems by further break-up analysis with different polyelectrolytes. Different sized silica and clay particles have been investigated as stabilizer. The size of powder particles in dispersion was studied by dynamic light scattering with a Zetasizer Nano and Laser light diffraction with Mastersizer (Malvern, UK). The surface electrical properties of surfactant modified particles, leading to alteration of interfacial liquid properties, as well as phospholipid/protein complexation in solutions, were studied by charge compensating polyelectrolyte titration with a particle charge detector PCD 03 (Mütek, Germany). Particles/surfactant interactions leading to changing their collective properties, such as segregation, sedimentation, coalescence, flocculation were investigated by a novel centrifugal method with a LUMiSizer (L.U.M., Germany), which allows obtaining space- and time-resolved extinction profiles including valuable information about particle/surfactant interactions. The influence of different parameters such as the kerosene/water-ratio, a kind of surfactant (pure or technical), and particles size on the emulsion stability are reported.

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Fig. 1. Microscopic images of suspo-emulsions containing SDS with (a) 1% Aerosil OX50 particles and (b) 1% Aerosil 380

112 ,

Sticky removal from wastewater, characterized by dynamic surface measurements ,

Gudrun Petzold , Leibniz - Institut fur Polymerforschung Dresden e.V. , Germany ,

Lars Schonberger , Leibniz - Institut fur Polymerforschung Dresden e.V. , Germany ,

Sabine Genest , Leibniz - Institut fur Polymerforschung Dresden e.V. , Germany ,

Simona Schwarz , Leibniz - Institut fur Polymerforschung Dresden e.V. , Germany.

Modified starch with cationic as well as hydrophobic units can be used to remove negatively charged substances from paper recycling, so called stickies. The interactions between different types of starch and a negatively charged model suspension, obtained by cooking domestic newspaper, have been studied using polyelectrolyte titration, nephelometric turbidity measurement, and determination of the carbon content. In addition, we were able to show that the dynamic interface tension is a very suitable property to characterize the surface active compounds in the model suspension and so to receive additional information about the sticky content of the wastewater. Polyelectrolyte complexes were formed due to the addition of cationic starch to the anionically charged model suspension. At a certain mixing ratio their precipitation leads to a significant reduction of the turbidity and the carbon content whereas the surface tension increases due to sticky removal. Among starches with the same degree of cationic charge, those with the highest hydrophobicity were most effective.

113 ,

New microemulsion cleaners as replacement for solvents ,

Renate Beisser , FZ Julich , Germany ,

Jurgen Allgaier , FZ Julich , Germany ,

Jens Hillerich , Bernd Schwegmann GmbH & Co. KG , Germany.

Although cleaning processes nowadays are based to a large extent on aqueous systems, solvents still play a significant role. This is especially the case in the construction sector, where solvents are used as brush cleaners or for the removal of adhesive or sealing compound residues. It is obvious that aqueous cleaners are of limited use for such applications. The use of solvent based cleaners, however, is accompanied by severe health and environmental risks. The health aspect is of special relevance as such cleaning agents are used to a large extent in enclosed rooms and by persons who are not trained to work with hazardous substances. The newly developed cleaners are free from volatile organic compounds (VOC), and for this reason basically odourless. The organic phase entirely consists of readily biodegradable and non-hazardous ester oils. Compared to state-of-the-art cleaners the new formulations do not require other co-solvents to improve the cleaning power or the microemulsion stability. In addition, they are stable over a wide temperature range, even at low surfactant contents. The combination of anionic and non-ionic surfactants allows lowering the surfactant concentration below 5 % and still keeping the temperature window for microemulsion stability at least between 5 °C and 40 °C. Besides minimizing the costs, low surfactant concentrations are the key to the formulation of non-hazardous cleaners. Although the new formulations contain water as the main component, their cleaning properties are essentially similar to conventional solvent cleaners. Cleaning experiments were carried out to test the use as brush cleaner. In

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this application the paint removal was similar for the new and the conventional cleaners. However the cleaning process was slower for the microemulsions, which can be attributed to the visibly higher viscosity. On the other hand, the microemulsions could remove dry paint from the brushes, what was only partially successful in case of the conventional cleaners. Further cleaning experiments were carried out in order to remove adhesives and silicon sealing compounds. Again similar results were obtained for the different cleaners. In the frame of these experiments it turned out that because of the low volatility, the microemulsion cleaners are superior to solvent cleaners if longer exposure times are required. In summary the new microemulsion cleaners are ideally suited as replacement for solvent cleaners in areas where fully aqueous systems are useless. Besides the environmental advantages, the new microemulsions are classified non-hazardous.

115 ,

The investigation of liquid films by the LIFT Tensiometer ,

Libero Liggieri , CNR-Istituto per l'Energetica e le Interfasi, Genova , Italy ,

Francesca Ravera , CNR-Istituto per l'Energetica e le Interfasi, Genova , Italy ,

Eva Santini , CNR-Istituto per l'Energetica e le Interfasi, Genova , Italy ,

Michele Ferrari , CNR-Istituto per l'Energetica e le Interfasi, Genova , Italy ,

Jurgen Kregel , Max Planck Institute of Colloids and Interfaces , Germany ,

Georgi Gochev , Max Planck Institute of Colloids and Interfaces , Germany ,

Reinhard MIller , Max Planck Institute of Colloids and Interfaces , Germany ,

Alexander V. Makiesvki , Sinterface Technology - Berlin , Germany ,

Boris A. Noskov , St.Petersburg State University - Dept. Colloid Chemistry , Russian Federation.

The chemico-physical properties of liquid films (LF) play an important role in different natural phenomena and technologies, particularly those concerned with emulsions and foams. Today different surface active species are utilised to stabilise the LF, such as surfactants, proteins, polymers and solid particles, which strongly affects the surface tension and the dilational rheology of the film interfaces. The behaviour of LF results however quite differently from that of single interfaces, due to its volume finiteness and small thickness, which limits the exchange of molecules with the bulk and makes the adsorption layers at the two sides of the films to interact. Based on an application of Capillary Pressure tensiometry, the Liquid Film Tensiometer (LIFT) has been conceived as an instrument for an accurate investigation of spherical films that will provide the measurement of dynamic film tension and dilational film rheology, associated with measurements of the thickness evolution. Here we will provide an overview of the technique with some exemplifications. The LIFT concept has been adopted to develop with the support of the Italian Space Agency a special apparatus for the investigation of LF onboard the International Space Station. Weightlessness conditions are in fact useful to study the properties of the film only subject to capillary drainage and will also allow investigating these properties in the wet film regime. Such instrument will also include enhanced optical techniques for the simultaneous measurement of the film thickness. References: 1. Y.H. Kim, K Koczo, D. T. Wasan, J. Colloid Interface Sci.,187 (1997) 29 2. V.I. Kovalchuk; J. Krägel, A.V. Makievski, F. Ravera, L. Liggieri, G. Loglio, V.B. Fainerman, R. Miller, J. Colloid Interface Sci., 280 (2004) 498. 3. R. Gabrieli, G. Loglio, P. Pandolfini , A. Fabbri, M. Simoncini, V.I. Kovalchuk, B.A. Noskov, R. Miller, F.

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Ravera, L. Liggieri. Spherical Cap-Shaped Emulsion Films: Thickness Evaluation at the Nanoscale Level by the Optical Evanescent Wave Effect. Colloids and Surfaces A, submitted 2012. Acknowledgements: - Italian Space Agency, project LIFT-Liquid Film Tensiometer , Call Opportunity 2007 . - Selex-Galileo, Campi Bisenzio (Italy) - European Space Agency, project PASTA-Particle Stabilised Emulsions (AO-2009 0813).

116 ,

Dilational Rheology, Structure and Phase Behavior of Mixed Lipid-Nanoparticle Monolayers ,

Francesca Ravera , CNR-Istituto per l'Ebergetica e le Interfasi , Italy ,

Eduardo Guzman , CNR-Istituto per l'Ebergetica e le Interfasi , Italy ,

Eva Santini , CNR-Istituto per l'Ebergetica e le Interfasi , Italy ,

Michele Ferrari , CNR-Istituto per l'Ebergetica e le Interfasi , Italy ,

Libero Liggieri , CNR-Istituto per l'Ebergetica e le Interfasi , Italy.

Lipid monolayers spread on aqueous phases have been extensively investigated in recent years because of their well recognized appropriatness as models for studying biologicacally relevant systems sucg as cellmembrane and lung surfactant. Moreover, studying the interaction of these layers with nanoparticles (NP) is of great importance as a first approach to understand the interaction of NP with living systems and more generally to develop innovative biomaterials. The here presented work focuses on the interaction between NP of different chemical nature (silica, carbon, titania) and mixtures of lipids mimicking the surface behaviour of the pulmonary surfactants (DPPC, DOPC, Palmic acid). The effects of the NP on the interfacial properties of such layers were investigated by using a set of complementary techniques. Langmuir trough was utilized to investigate the modifications induced by NPs on the phase behavior of spread lipid layers. Such information were complemented by those on the lateral and vertical structure of the mixed layers accessed by Brewster Angle Microscopy and Ellipsometry. Moreover, the mechanical features of these mixed layers were investigated by the Oscillating Barrier method in the Langmuir trough and by the Oscillating Bubble method in a drop shape tensiometer. These latter rheological studies were especially effective to evaluate surface re-organization processes involving lipid molecules and NP. Depending on the NP characteristics and concentration, the results have evidenced a variety of complex interactions between particles and lipids, such as lipid sequestration via adsorption at the particle surface or particle incorporation in the monolayer. In particular, the formation of NP-lipid complexes incorporated in the monolayers induces changes in their phase behaviour and structure as well as in the dynamical response to area perturbation. Regards the effects of NP on the simulated pulmonary surfactant, these studies provided the definition of parameters which could be suitably utilised to score NPs for their potential adverse impact on the respiratory physiology. References: 1. E. Guzmán, L. Liggieri, E. Santini, M. Ferrari, F. Ravera, Soft Matter, 8 (2012), 3938-3948 2. E. Guzmán, L. Liggieri, E. Santini, M. Ferrari, F. Ravera, Effect of Hydrophilic and Hydrophobic Nanoparticles on the Surface Pressure Response of DPPC Monolayers. J. Phys. Chem. C 115 (2011), 21715-21722. 3. E. Guzmán, L. Liggieri, E. Santini, M. Ferrari, F. Ravera, Influence of silica nanoparticles on phase behavior and structural properties of DPPC—Palmitic acid Langmuir monolayers. Colloids Surf. A, 2012, doi: 10.1016/j.colsurfa.2011.11.023.

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117 ,

Separable Chelating Agents ,

Hakan Edlund , Mid Sweden University , Sweden ,

Ida Hogberg , Mid Sweden University , Sweden ,

Susanne Boija , Mid Sweden University , Sweden , Gerd Persson , Mid Sweden University , Sweden ,

Magnus Norgren , Mid Sweden University , Sweden.

In this study we have investigated separable chelating agents that can be regenerated and reused, and the metal ions can be recovered in a second step. The chelating agents were synthesized with multiple chelating sites, represented by carboxyl units and tertiary amines, whereby coordination complexes with metal ions can be formed. We report on the physicochemical characterisation of chelates, chelating surfactants and their metal complexes.

118 ,

Atomic Force Microscopy studies on Langmuir-Blodgett Films of Lipids-Nanoparticles Mixed Systems ,

Eduardo Guzman , CNR-Istituto per l'Energetica e le Interfasi , Italy ,

Michele Ferrari , CNR-Istituto per l'Energetica e le Interfasi , Italy ,

Libero Liggieri , CNR-Istituto per l'Energetica e le Interfasi , Italy ,

Eva Santini , CNR-Istituto per l'Energetica e le Interfasi , Italy ,

Francesca Ravera , CNR-Istituto per l'Energetica e le Interfasi , Italy.

The study of the interaction of nanoparticles (NP) with lipid monolayers is a topic of great interest since these systems can be used as in vitro models to evaluate potential toxicological alterations, induced by nanoparticulate materials in biological relevant systems (lung surfactant, cellular membranes). Recent studies have pointed out that the presence of nanoparticles produces significant modifications in the equilibrium and mechanical properties of lipid monolayers, affecting strongly the physico-chemical physiologically relevant parameters (collapse pressure, equilibrium elasticity or linearity of the response to oscillatory deformations). These modifications are observed independently of the nanoparticles nature [1].

In this work, the structural effects of different types of nanoparticles (hydrophilic and hydrophobic silica, hydrophobic carbon black) on mixed lipid monolayers, with DPPC (Dipalmitoylphosphatidylocholine) as major component, have been investigated using Atomic Force Microscopy (AFM). For this purpose, different Langmuir-Blodgett films, deposited at different degrees of monolayers compression, have been analyzed. The results pointed out that the effect of the nanoparticles is mediated by the penetration of these to the lipid monolayers that disrupts the film structure, affecting the packing of the lipids molecules and consequently reducing the cohesion interactions in the monolayer, corroborating the results of previous studies [2, 3]. In addition to the structural characterization, preliminary essays were carried out according to the colloidal probe method, aimed at elucidating how the penetration of nanoparticles can change the adhesion properties of lipids layers and consequently some physiological functionality.

References:

1. E. Guzman, L. Liggieri, E. Santini, M. Ferrari, F. Ravera, J. Phys. Chem. C 115 (2011) 21715.

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2. E. Guzman, L. Liggieri, E. Santini, M. Ferrari, F. Ravera, Colloids Surf. A (2012) doi:10.1016/j.colsurfa.2011.12.059. 3. E. Guzman, L. Liggieri, E. Santini, M. Ferrari, F. Ravera, Soft Matter 8 (2012) 3938.

Acknowledgements:

- Italian Institute of Technology (IIT): project SEED 2009 ‚ NIPS-Nanoparticle Impact of Pulmonary Surfactant Interfacial Properties

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Effect of the frother overdosage on kinetics of the three-phase contact formation at hydrophobic surfaces ,

Dominik Kosior , Institute of Catalysis and Surface Chemistry PAS , Poland ,

Jan Zawala , Institute of Catalysis and Surface Chemistry PAS , Poland ,

Kazimierz Malysa , Institute of Catalysis and Surface Chemistry PAS , Poland.

Presence of the surface active substances has significant implication in mineral processing, e.g. effective flotation without flotation reagents is almost impossible. Flotation frothers main tasks are to: form a froth layer of a desirable stability, increase a degree of the gas phase dispersion (smaller bubbles), prevent coalescence of the bubbles formed and facilitate the three-phase contact (TPC) formation. Frothers are surface active substances adsorbing preferentially at solution/gas interface. Their adsorption at the bubble surface causes lowering of the bubble rising velocity (up to over 50%), what leads to prolongation a time of the bubble and grain collision. Timescale of the TPC formation process is affected by many factors and hydrophobicity of the solid surface is one of the most important. As affinity to air is a typical feature of all hydrophobic surfaces, therefore, air can be always present at such surface (in a form of micro- and nano-bubbles) and affect the kinetics of the TPC formation and attachment of the colliding bubble. The paper presents results of studies on influence of frothers (n-octanol and α terpineol) concentration on kinetics of the TPC formation and attachment of the colliding bubble to Teflon surfaces of different roughness. The roughness of Teflon plates was varied from ca. 1-100 µm and high-speed camera (1040 frames per second) was used to monitor the rapid phenomena occurring at the collisions. As motion induces non uniform coverage over surface of the rising bubbles (dynamic adsorption layer (DAL) formation), so experiments were also carried out for the Teflon plates located in distance L= 3 mm and 250 mm from the capillary. For L= 3 mm the bubble is at the acceleration stage, its velocity is much smaller than terminal one and the bubble adsorption coverage is still almost uniform [1]. Generally, larger roughness of the Teflon surface resulted in a significant shortening the time of the TPC formation (tTPC). For example in clean water, the increase of the Teflon surface roughness from ca. 1 to 80 μm caused shortening the tTPC values from 105 to a few milliseconds only. At low α-terpineol and n-octanol concentrations the tTPC values were systematically smaller for all Teflon surface roughness, due to lowering by the frothers the bubble impact velocity. However, at high frothers concentrations the time of TPC formation tTPC was prolonged, despite that the bubble impact velocities did not change. For example at smooth (1µm) Teflon surface, located 250 mm from capillary the tTPC increased from 47 to 129 ms when n octanol concentration increased from 3e-5M to 1e-3M. Similar effect was observed also in α terpineol solutions. The prolongation of the tTPC at high frothers concentration indicates that air (micro- and/or nano-bubbles) was present at the Teflon surfaces and the TPC was formed as a result of rupture of the liquid (foam) films separating the colliding bubble and air pockets at the Teflon surface. Reference: 1. M. Krzan, J. Zawala, K. Malysa, Colloids & Surfaces A:, 298 (2007) 42-51.

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120 ,

Surfactant solutions and dispersed systems at superhydrophobic surfaces in air and liquid environment ,

Michele Ferrari , CNR - Istituto per l'Energetica e le Interfasi, Genova , Italy ,

Eva Ravera , CNR - Istituto per l'Energetica e le Interfasi, Genova , Italy ,

Eva Santini , CNR - Istituto per l'Energetica e le Interfasi, Genova , Italy ,

Guzman Eduardo , CNR - Istituto per l'Energetica e le Interfasi, Genova , Italy ,

Libero Liggieri , CNR - Istituto per l'Energetica e le Interfasi, Genova , Italy.

Amphiphilic molecules and dispersed systems in contact with highly water-repellent solid surfaces play key roles in research and technology, with increasing interest in different fields. Nevertheless, the wetting properties of aqueous surfactant solutions, non aqueous liquids or immiscible phases as in foams and emulsions on such superhydrophobic (SH) solid surfaces have been so far rarely investigated.[1] From self-cleaning materials to microfluidic devices many applications can exploit the wetting characteristic of nature-inspired surfaces showing contact angle above 150° and a very small hysteresis. In this work the SH surfaces were prepared by a mixed inorganic-organic coating on different substrates and studied in presence of different systems. Depending on the preparation SH surfaces show different aging resistance due to the composition and thickness of the hydrophobizing coating layer. Surfactant adsorption results in a switch between a Cassie-Baxter and a Wenzel regime for superhydrophobic surfaces at water-air. The partitioning features of surfactants strongly affect the oil-water interface wetting properties resulting in a switch between a Wenzel and a Cassie-Baxter regime.[2] Reference: [1] Ferrari M. Aqueous and Non-Aqueous Liquids on Superhydrophobic Surfaces:Recent Developments in Contact Angle, Wettability and Adhesion, Volume 6 Ed.K. L. Mittal, Brill- VSP (The Netherlands) 269 (2009). [2] Ferrari M., Ravera F. Surfactants and wetting at superhydrophobic surfaces: Water solutions and non aqueous liquids. In: Advances in Colloid and Interface Science, vol. 161 (1- 2) pp. 22 - 28. Physico-chemical and flow behaviour of droplet based systems. V.M. Starov, R. Miller, S. Guido (eds.).Elsevier B.V,2010

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Properties of interfacial layers formed by gelatin-polysaccharide complexes ,

Svetlana Derkach , Murmansk State Technical University , Russian Federation ,

Nikolay Voronko , Murmansk State Technical University , Russian Federation ,

Alexandra Maklakova , Murmansk State Technical University , Russian Federation ,

Lyudmila Petrova , Murmansk State Technical University , Russian Federation ,

Tatyana Dyakina , Murmansk State Technical University , Russian Federation.

Structure formation of the thin layers formed at an interface between aqueous phase and gas in gelatin-containing systems in the presence of anionic polysaccharides has been studied. Investigations of properties, structure and formation regularity of interfacial layers in multicomponent systems are of great importance in connection with emul¬¬sion stability, in particular, for the food technologies and producing food emulsion products. Surface phenomena in the systems studied is significantly determined by

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properties (hydrophilic- hydrophobic balance, mobility gelatin segments, lifetime, sizes of particles) of the macromolecular complexes of gelatin with anionic polysaccharide forming in the aqueous phase, which can be considered as a new type of high-molecular-weight surfactants. Moreover modification of gelatin due to the complex formation with different polysaccharides can be considered as an effective way for the regulation of the sol-gel transition within the thin adsorption interfacial layers. Surface rheology of quasi two-dimensional (2D) adsorption layers formed by macromolecular complexes of gelatin with anionic polysaccharides carrageenan and alginate at the interface of aqueous phase/gas has been investigated. Rheological parameters (viscosity, elasticity modulus, yield stress) of interfacial layers are measured under shearing strain. The rheological investigations are considered as a key to understanding process of forming interfacial layers of gelatin-anionic polysaccharide complexes. Under the definite concentrations of gelatin and polysaccharide electrostatic interactions of these charged polyelectrolytes lead to formation of soluble macromolecular complexes in the aqueous phase. Effective radius and z-potential of the complexes’ particles forming in the bulk under the different components mass ratio have been determined. Polysaccharide content increase more than definite value resulted in the dramatic rise of particles’ size. Investigation of thermodynamic properties of gelatin-polysaccharide complexes shows that these ones are surface-active. Adsorption of gelatin-polysaccharide complexes, in consequence of its surface activity, at the interface results in formation of a thin interfacial layer that is related to phase transition. The elasticity modulus of the layers indicates the creation of gel as a third phase being in equilibrium with the aqueous (gelatin-polysaccharide sol) phase. Process is accompanied by an increase in surface viscosity. The rheological properties of the interfacial layers are time-dependent that can be explained by gel-like structure formation upcoming in time. The influence of anionic polysaccharide additions on rheological behavior of the gelatin interfacial layers as a sensitive parameter for changes has been studied. In the case of polysaccharide, elasticity modulus and viscosity increase sharply and principally depend on the polysaccharide /gelatin mass ratio. Analysis of the experimental data and influence of gelatin-carrageenan complexes’ structure (size and z-potential of particles) forming in the aqueous phase on the rheological behavior of adsorption interfacial layers has been carried out. Changing the composition and charge of the gelatin-anionic polysaccharide complexes upon the different mass component ratio and pH it is possible to produce adsorption interfacial layers of different rheological properties. The work is supported by the Russian Foundation for Basic Research (the project N 10-03-00310-а).

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Understanding Structures of Athabasca Bitumen at air/water interfaces by Brewster Angle Microscopy (BAM) of Langmuir films ,

Yujuan Hua , CanmetENERGY,Natural Resources Canada , Canada ,

Chandra W. Angle , CanmetENERGY, Natural Resources Canada , Canada.

Bitumen films formed on water surfaces have negative effects for both environment and economy. CanmetENERGY has put emphasis and effort into understanding the structures of the bitumen films on water as a necessary step before optimization of bitumen for extraction. Detailed structures of the adsorbed molecules, especially the role of asphaltene molecules at the interfaces are still under scrutiny and debate. In the present study, in order to achieve a clearer understanding of bitumen film structures we compare bitumen and asphaltenes films as they are compressed and expanded to various surface pressures. We have used a customized NIMA Langmuir trough interfaced to a Brewster Angle microscope and CCD camera (Accurion, previously Nanofilm Gmbh) to study the images of bitumen films at the air/ water interface. The bitumen film appeared uniform with high reflectivity in the liquid expanded (LE) phases (5-18 mN/m) after which it exhibited a coarse pebble like interface with decreased reflectivity in the liquid condensed (LC) phase (18-35 mN/m). During the first cycle of compression asphaltenes films showed well defined phase transitions and a smooth interfacial uniformity in the liquid condensed phase

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between 9 mN/m to 35 mN/m. However, folding or buckling occurred at surface pressures from 35 to 44 mN/m. On expansion asphaltene films appeared to break into islands. The hysteresis of the pressure–area isotherm was much larger than that for bitumen. In both compression and expansion cycles BAM images for bitumen films appeared to be more reproducible than that of the asphaltenes films at the same surface pressures. Asphaltenes films occupied larger areas than the bitumen at similar surface pressures. The resins in bitumen played an important role in determining interfacial properties of bitumen films.

123 ,

From superhydrophobic to superamphiphobic coatings ,

Doris Vollmer , Max Planck Institut for Polymer Research , Germany ,

Xu Deng , Max Planck Institut for Polymer Research , Germany ,

Lena Mammen , Max Planck Institut for Polymer Research , Germany ,

Periklis Papadopoulos , Max Planck Institut for Polymer Research , Germany ,

Hans-Jurgen Butt , Max Planck Institut for Polymer Research , Germany.

124 ,

Phase behaviour of microemulsions with weak and strong surfactants ,

Doris Vollmer , Max Planck Institut for Polymer Research , Germany ,

Harsha Paroor , Max Planck Institut for Polymer Research , Germany.

Microemulsions are thermodynamically stable, isotropic mixtures of water, oil and surfactant. Depending on the temperature and concentration, surfactant molecules associate into a micellar, lamellar, hexagonal or sponge like bicontinous structure. To quantitatively predict the phase behavior we proposed a modified Helfrich equation describing the morphologies. It assumes that within a well-defined temperature interval two spontaneous curvatures coexist. To investigate the validity of this assumption we investigate the phase boundaries by various measurements. The spontaneous curvature is calculated from fitting the emulsification boundaries. Experimentally determined values for the phase transition temperatures and specific heat have been successfully fitted to the unified model.

125 ,

Effect of phase separation on the properties of lipid monolayers ,

Svetlana Baoukina , University of Calgary , Canada ,

Eduardo Mendez-Villuendas , University of Calgary , Canada ,

D. Peter Tieleman , University of Calgary, Canada.

We used computer simulations to study the effect of phase separation on the properties of lipid monolayers. This is important for understanding lipid-lipid interactions underlying lateral heterogeneity (rafts) in biological membranes, and the role of domains in regulation of surface tension by lung surfactant. Molecular dynamics simulations with the coarse-grained force field MARTINI were employed to achieve large length (100 nm in lateral dimension) and time (tens of microseconds) scales. Lipid

110 SIS2012

mixtures containing saturated and unsaturated lipids and cholesterol were investigated under varying surface tension and temperature. Compositional lipid de-mixing and coexistence of liquid-expanded and liquid-condensed phases, as well as liquid-ordered and liquid-disordered phases was reproduced. Formation of the more ordered phase was induced by lowering the surface tension or temperature. Phase transformations occurred via either nucleation or spinodal decomposition. Using cluster analysis combined with Voronoi tessellation we characterized in detail the structure and dynamics of monolayers with domains. Partial areas of lipids in each phase, phase composition, boundary length, and line tension were characterized as a function of surface tension. At low surface tensions, the monolayers rich in cholesterol manifest spontaneous curvature of domains. Lateral diffusion of lipids is significantly slower in the more ordered phase, as expected. The calculated growth exponents indicate that upon nucleation the growth of a more ordered phase is controlled by Ostwald ripening at early stages, followed by Brownian coagulation. We also simulated lipid monolayers connected to bilayer reservoirs in water, which are relevant for the function of lung surfactant. The distribution of phases between the monolayers and bilayers was determined, confirming the modified squeeze-out mechanism. Nucleation of bilayer folds upon monolayer collapse occurs in the more disordered phase in the case of flat domains, and at the phase boundary in the case of domains with curvature. The latter also facilitate monolayer collapse from the interface.

126 ,

Study of interactions in aqueous solutions between a surfactant nonionic and added electrolyte: Effect on cloud point. ,

LISBETH GIESURIN , C.A. Venezolana de Pinturas. Valencia, Venezuela , Venezuela ,

HUGO PARRA , C.A. Venezolana de Pinturas. Valencia, Venezuela , Venezuela ,

JUAN PINTO , C.A. Venezolana de Pinturas. Valencia, Venezuela , Venezuela ,

JUAN PEREIRA , Laboratorio de Petroleo, Hidrocarburos y Derivados, Departamento de Quimica, Facultad Experimental de Ciencias y Tecnologia, Universidad de Carabobo, Valencia , Venezuela.

Nonionic surfactants are useful in many indrustrial emulsions 1. They show ability to design the required degree of solubility into the molecule by the careful control of the size of the hydrophilic group. An interesting characteristic of the polyoxyethylene (POE) family is that they exhibit an inverse temperature‚Äìsolubility relationship; The temperature at which components of the POE surfactant begin to precipitate from solution is defined as the cloud point (CP). In this work were measured cloud points of nonionic surfactant in the presence of different electrolytes. The aim was to study the interactions between the surfactant and the different ions with different charge densities. The electrolytes were evaluated: NaCl, CaCl2, Al2(SO4)3, CaSO4, AlCl3, MgCl2, MgSO4, Na2SO3, Na5P3O10. Here, experiments were carried out keeping the concentration of surfactant constant, 1% mass/volume, and varying the electrolyte concentration. Usually, it was observed that increasing the concentration of each electrolyte showed a decreasing in CP. For electrolyte concentration equals 2 mol/L sodium chloride (NaCl) showed a decreasing of temperature in 45.40%; calcium chloride CaCl2, temperature decreasing in 29.26%. For polyelectrolyte decreasing was in 26.47% at a concentration of 0.01 mol/L. The above results suggest that exists an influence of the nature and concentration of electrolytes on the hydrophilicity of the surfactant micelles in aqueous solution. This phenomenon might influence the action of surfactants in interfacial properties such as dispersion and wettability2. In addition, have been investigated the different surfactants aqueous solutions, with and without electrolytes, by use of differential scanning calorimetry (DSC), to correlate the results of CP and phase transitions in each system.

127 ,

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Role of asphaltenes in stabilizing W/O emulsions ‚ A thin liquid film study ,

Plamen Tchoukov , Dept. of Chemical and Materials Eng., University of Alberta, Edmonton , Canada ,

Fan Yang , Dept. of Chemical and Materials Eng., University of Alberta, Edmonton , Canada ,

Zhenghe Xu , Dept. of Chemical and Materials Eng., University of Alberta, Edmonton , Canada ,

Tadeusz Dabros , CanmetENERGY, Natural Resources Canada, Devon , Canada ,

Jan Czarnecki , Dept. of Chemical and Materials Eng., University of Alberta, Edmonton , Canada ,

Johan Sjoblom , Ugelstad Laboratory, Department of Chemical Engineering, Norwegian University of Sciences and Technology (NTNU), Trondheim , Norway.

Formation of stable W/O emulsions is inevitable and highly undesirable in the petroleum industry. Emulsified water, in the form of micron size water droplets, carry salts and causes severe corrosion problems for downstream refineries and transporting pipelines. Among other crude oil and bitumen fractions, the asphaltenes are recognized to be the main stabilizing agent of W/O emulsions. However, the mechanisms of asphaltene contribution to the emulsion stability are not fully understood. Properties of the thin oil films that separate approaching water droplets play a key role for the stability of emulsions. Microinterferometric thin liquid film technique is used to study drainage kinetics, thicknesses and stability of water-in-oil thin films. Intervening thin liquid films formed from asphaltenes-, maltenes- (deasphalted bitumen) and bitumen- (without solids) in toluene solutions between two water droplets are compared. The results show that asphaltenes stabilize thin films at much lower concentrations of 0.5 g/L than corresponding concentrations for maltenes and bitumen of above 10 g/L. The drainage of intervening liquid films formed from asphaltene in toluene solutions is significantly slower than films formed from maltenes and bitumen in toluene solutions. The difference cannot be explained with variations of interfacial tension or bulk viscosity of the solutions. The films of 40 - 90 nm stabilized by asphaltenes are much thicker than the films of 11 nm thick stabilized by maltenes. Such large difference in the film thicknesses points to different operative surface forces and mechanisms of film stabilization. Buildup of 3D network in the film with characteristic length well beyond reported in the literature gives rise to long-range repulsive forces and modifies the rheological properties of the film liquid, resulting in slower drainage kinetics, and thicker and more stable intervening thin liquid films that separate water droplets in W/O emulsions.

128 ,

Effect of thermal substrate conductivity on the evaporation mode of droplets of colloidal suspensions ,

Vahid Bazargan , University of British Columbia , Canada ,

Boris Stoeber , University of British Columbia , Canada.

The evaporation of sessile droplets of colloidal suspensions in still air has been studied by several different groups [1-9]. The presence of particles in the fluid has been shown to have a strong effect on the interfacial forces and hence the behavior of the contact line [1]. Based on this, two evaporation modes of droplets have been identified; evaporation with pinned and de-pinned contact line. The actual evaporation of the droplets is believed to be a combination of these modes of evaporation [6]; when the evaporation starts the droplet is at its equilibrium contact angle with a contact line of constant radius (pinned mode) followed by a second phase of radius shrinkage with a fixed contact angle (de-pinned mode). Evaporation with a pinned contact angle is known to be responsible for the coffee ring phenomenon during the evaporation of a colloidal suspension [1, 2, 4-8] where a fixed contact line is associated with an outward flow inside the droplet that deposits the solutes near the contact line [Hu and

112 SIS2012

Larson].

For small droplets the rate of evaporation is limited by the diffusion rate at which vapour dissipates into the ambient environment [8]. The latent heat of evaporation is conducted through the droplet and the substrate. The vapour diffusion and heat transfer rates directly influence the total evaporation time of the droplet and the pinning/de-pinning transition point during the evaporation. The effect of vapour diffusion on this process has recently been studied [3, 9]. However while the experimental results confirm the effect of the thermal conductivity of the substrate and the droplet [10, 11], the effect of the substrate conductivity has not been investigated yet. In this study, this effect of thermal conductivity of the substrate has been determined using a numerical model, and the results have been confirmed by experiments.

References: [1] R. D. Deegan, O. Bakajin, T. F. Dupont, G. Huber, S. R. Nagel and T. A. Witten, Contact line deposits in an evaporating drop, Physical Review E, vol. 62, pp. 756-765, 2000. [2] H. Masoud and J. D. Felske, Analytical solution for inviscid flow inside an evaporating sessile drop, Physical Review E, vol. 79, pp. 016301, 2009. [3] H. Hu and R. G. Larson, Evaporation of a sessile droplet on a substrate, The Journal of Physical Chemistry B, vol. 106, pp. 1334-1344, 2002. [4] H. Hu and R. G. Larson, Analysis of the microfluid flow in an evaporating sessile droplet, Langmuir, vol. 21, pp. 3963-3971, 2005. [5] Y. Y. Tarasevich, Simple analytical model of capillary flow in an evaporating sessile drop, Physical Review E, vol. 71, pp. 027301, 2005. [6] R. Picknett and R. Bexon, The evaporation of sessile or pendant drops in still air, J. Colloid Interface Sci., vol. 61, pp. 336-350, 1977. [7] L. Y. Barash, T. Bigioni, V. Vinokur and L. Shchur, Evaporation and fluid dynamics of a sessile drop of capillary size, Physical Review E, vol. 79, pp. 046301, 2009. [8] V. A. Kuz, Fluid dynamic analysis of droplet evaporation, Langmuir, vol. 8, pp. 2829-2831, 1992. [9] E. Widjaja and M. T. Harris, Numerical study of vapor phase-diffusion driven sessile drop evaporation, Comput. Chem. Eng., vol. 32, pp. 2169-2178, 2008. [10] G. Dunn, S. Wilson, B. Duffy, S. David and K. Sefiane, The strong influence of substrate conductivity on droplet evaporation, J. Fluid Mech., vol. 623, pp. 329-351, 2009. [11] W. Ristenpart, P. Kim, C. Domingues, J. Wan and H. Stone, Influence of substrate conductivity on circulation reversal in evaporating drops, Phys. Rev. Lett., vol. 99, pp. 234502, 2007.

129 ,

Xanthation modified polyacrylamide in sulfide mineral flotation and its mechanism investigation ,

Lei Wang , University of Alberta , Canada ,

Kaipeng Wang , University of Alberta , Canada ,

Qi Liu , University of Alberta , Canada.

Polymer depressant with high molecular weight has the potential to be used in fine particle flotation due to its dual function: selective depressive effect and flocculation effect. In this study, a novel xanthation modified polyacrylamide, named PAM-X, was synthesized from non-ionic polyacrylamide (with molecular weight of ~5,000,000) and tested in single sulfide mineral flotation. It was found that PAM-X and PAM exhibited unique but opposite selectivity in alkaline solution: while PAM can depress sphalerite but not galena, PAM-X can only depress galena. The adsorption mechanism was investigated by ATR-FTIR, showed that PAM-X had different band shifts when adsorbed on to galena and sphalerite surface. Zeta potential tests showed that PAM-X and PAM could differently change the electrokinetic property of galena and

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sphalerite, indicating they have different formation when adsorbed on mineral surface. Photometric Dispersion Analyzer (PDA) was used to measure the degree of flocculation. It was found that galena, sphalerite and their mixture all can get flocculated by PAM-X/PAM but have different degree of flocculation. PAM-X and PAM could be potentially used in differential sulfide mineral separation to replace traditional hazardous inorganic depressants.

130 ,

Mixing Characterization and Scale-up of Additive Performance: Comparison of a Bench Scale Stirred Tank with the Shear and Sedimentation Test Cell (SSTC) ,

Marcio Machado , University of Alberta , Canada ,

Suzanne Kresta , University of Alberta , Canada.

The addition of solids or liquids into solutions is a very important issue in industrial processes such as oil sands, drinking water treatment, cosmetics and personal care products, and paints and coating. The effectiveness of these industrial processes is improved if efficient dispersion and dissolution of the additives is achieved. It is known that current bench scale tests do not always represent the the industrial scale behavior. Having a bench scale stirred tank operating in the fully turbulent regime instead of transitional flow is a critical step for process scale-up, since a tank operating in transitional flow at the bench scale cannot be reliably scaled-up.

It is well established in the literature that a stirred tank is operating in fully turbulent flow when the Reynolds number is over 20,000, but this assumption is based on data for the impeller discharge stream. The present work considers two tank geometries to study if they are operating in turbulent regime in different Reynolds numbers: a standard stirred tank widely used in the mixing research area (H = T = 24 cm) and a Shear and Sedimentation Test Cell (SSTC) that has been developed by this research group (T = 7.6 cm, H = 3T). The SSTC (T=7.6 cm, H=3T) provides more uniform intensity of mixing over the volume of the tank, uses a much smaller volume of sample than the traditional stirred tank, and allows for the possibility of a sedimentation step after the mixing step with no sample transfer required. The unique geometry of the SSTC allows a more uniform turbulence distribution, which is not obtained in the other bench scale tests. Mean velocity profiles were measured at different axial positions of the tank using a Laser Doppler Velocimeter. Several impeller shapes, impeller diameters and fluids were used in order to check their effect in the flow. Several velocity profiles for each geometry were taken and the regime was considered turbulent in a particular Reynolds number if the correspondent velocity profile was self-similar to others collected in different Reynolds numbers. The results showed that for the standard stirred tank, the upper third of the tank drops into the transitional flow regime at Re = 20,000. Larger Reynolds numbers are necessary to keep the flow in the fully turbulent regime close to the surface of the liquid. The recirculation part of the tank, where the fluid is moving back towards the impeller, is usually operating in transitional regime, even at Reynolds numbers much larger than 20,000.On the other hand, the SSTC was able to keep the flow turbulent even at Re < 10000. These results have implications both for scale-up and for many industrial applications with surface feed or with dip pipes in the top third of the tank.

131 ,

Modeling Contact Angles of Surfactant Solutions on Smooth and Rough Heterogeneous Surfaces ,

Andrew J. B. Milne , University of Alberta - Mechanical Engineering , Canada ,

Janet A. W. Elliott , University of Alberta - Chemical and Materials Engineering , Canada ,

114 SIS2012

Alidad Amirfazli , University of Alberta - Mechanical Engineering , Canada.

Using Gibbs’ adsorption equation, the Cassie Equation, and a literature isotherm, a new model has been derived, describing the effect on equilibrium contact angles of surfactant adsorption at the liquid-vapor (l-v), solid-liquid (s-l), and solid-vapor (s-v) interfaces for surfactant solutions on smooth and rough heterogeneous surfaces. The inclusion of the s-v adsorption terms allows the model to successfully predict experimental data for contact angle on surfaces displaying the autophobic effect with surfactant solutions. Using representative values for the coefficients describing adsorption to each interface, model

predictions for contact angles as a function of m

f parameters (area fractions, actual wetted area of

material m divided by total projected area under the drop) and surfactant concentration are made for heterogeneous surfaces made up of different materials.

On heterogeneous smooth surfaces, it is seen that the m

f parameters serve as weighting factors

determining how to combine the effects of surfactant adsorption on each material to predict the behavior on the heterogeneous surface. The combination leads to more complicated predictions of contact angle

versus concentration for surfactant solutions wetting a nearly homogeneous surface (one m

f value high,

another low) than for a perfectly homogeneous surface. Specifically, at a given concentration the inclusion of a small amount of material that is hydrophobic at that concentration has a greater effect on a

hydrophilic material than vice versa. This is because the m

f factors act on the concentration dependent

cosine of the contact angles for surfactant solutions on each material, so that a small change in the cosine at low contact angles has a large effect. The level of complexity in model predictions increases with the number of different materials present on the surface and with more equal weighting of different materials.

Rough heterogeneous surfaces are seen to behave similarly to previous work1. However, the combination

of roughness and heterogeneity adds an additional variable, indicating that the contact angle of surfactant solutions on rough heterogeneous surfaces can take a rich variety of values. In penetrated

(Wenzel mode) wetting, roughness (

m

mf 1 ) is seen to amplify the effects of surfactants. This

amplification leads to higher contact angles on hydrophobic surfaces, lower contact angles on hydrophilic surfaces, and increased variation in contact angle as concentration changes. Conversely, in unpenetrated wetting, the air remaining below the drop acts as an additional material making up the heterogeneous surface. Increasing fair (decreasing solid fraction), leads to an attenuation of the effect of surfactant adsorption. This decreases the variation in contact angle as concentration changes, and further leads to high contact angles (due to the 180° contact angle for liquid ‘on’ air).

The possible complexity of surfactant solution contact angle behavior on heterogeneous surfaces points to the importance of characterizing the heterogeneities of any surface under consideration. With proper characterization, the models described in this paper will allow for prediction of contact angles on such surfaces.

Reference:

1. Milne, A. J. B.; Elliott, J. A. W.; Zabeti, P.; Zhou, J.; Amirfazli, A. Physical Chemistry Chemical Physics 2011, 13, 16208.

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Dilational Interfacial Rheology for Increasingly Deasphalted Bitumens and n-C5 Asphaltenes in Toluene/NaHCO3 solution ,

Chandra W. Angle , CanmetENERGY, Natural Resources Canada , Canada ,

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Yujuan Hua , CanmetENERGY, Natural Resources Canada , Canada.

The current understanding of the properties and molecular structures of diluted bitumenl/water interfaces are being revised as new data are presented. Knowledge of the properties and behaviors of these interfaces under stresses are important in bitumen extractions, especially for remediating emulsions problems in production. In this paper we studied dilational interfacial rheology of toluene diluted, mineral free Athabasca bitumen, partially deasphalted Athabasca bitumen, and n-pentane (n-C5) asphaltenes derived from the same bitumen source. Partially deasphalted bitumens were prepared by adding increasing mass ratios of n-heptane (n-C7)-to-bitumen in order to precipitate asphaltenes. Both solvent free deasphalted bitumens and precipitated n-C7 asphaltenes were recovered. The soluble n-C5 asphaltenes remaining in the partially deasphalted bitumens were also characterized. Number average molecular weights of all oils and asphaltene samples were measured in toluene using Vapor Pressure Osmometry. Dilational interfacial rheological measurements were made by low deformation periodic oscillation of pendant drops previously aged in NaHCO3 solution. Dynamic interfacial tensions were measured independently during ageing. Gibbs surface excess properties and the critical amphiphiles concentration (CAC) were determined. Results showed that for all frequencies studied interfacial viscoelasticity of the Athabasca bitumen-in-toluene reached a maximum at 0.0019 mol•kg-1 (0.1wt%) then declined as the bitumen concentrations increased. For all drop oscillation frequencies, the n-C5 asphaltenes-in-toluene made up at the same concentrations as they occur in the diluted bitumen showed higher elastic and viscous moduli than those for the diluted bitumen. Both systems showed linear dependence and a rise of viscoelasticities when plotted against logarithm of frequencies of droplet oscillation. The n-C5 asphaltenes showed a higher gradient than that for the bitumen. For the partially deasphalted bitumens the interfacial viscoelasticity values showed a dependence on not only droplet oscillation frequency, but also on the bitumen molecular weights, the molecular weights of the soluble n-C5 asphaltenes, as well as resins/asphaltenes (R/A) mass ratios in the samples. At increased oscillation frequencies, the elastic modulus vs. MWt of bitumen followed second order polynomial relationships, and frequency isolines changed from concave to nearly linear and to convex at high frequencies. Similarly polynomial fits of elastic modulus vs. R/A mass fractions changed from concave to convex frequency isolines, but the high R/A of bitumens correlated with reduced elasticity. The similar fits for elastic modulus vs. MWt of soluble asphaltenes were less convex for higher frequency isolines. These results indicate that the concentrations and MWt of bitumens and consequently soluble n-C5 asphaltenes, and dilational frequency were all crucial to the interfacial tension and elasticity of the bitumen/water interfaces. Distinct differences between asphaltenes and bitumen in-toluene-water interfacial properties were observed. Oil composition is shown to be quite important in determining the interfacial behaviors of crude oils.

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Characterization of Biocompatible Polymerized Diyne PC Surfactant ,

Lei Pei , Department of Chemistry, University of Alberta , Canada ,

Charles Lucy , Department of Chemistry, University of Alberta , Canada.

Phospholipids such as phosphorylcholines (PC) form supported planar bilayers (SPB) on surfaces such as silica, making the surface biocompatible. Unfortunately such SPB are not very stable. Planar supported lipid bilayers can be stabilized through polymerization of the mono lipids [1][2] such as Dienoyl, Sorbyln Acryloyl surfactants and the diacetylene 1,2-bis (10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine (Diyne PC). The polymerization of the diacetylene group proceeds as a 1.4- addition reaction under UV radiation, which gives a fully conjugated structure to stabilize the bilayer membranes. Here we will present the polymerization of Diyne PC lipid both in aqueous solution and on a fused-silica surface. The conjugated structure and morphologic study after polymerization were characterized using UV-vis spectrum, fluorescence spectrum, capillary electrophoresis and AFM.

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134 ,

The velocity field near the moving contact line in an evaporating drop ,

Prashant Rakhmaji Waghmare , Micro and Nano-scale Transport Laboratory Department of Mechanical Engineering University of Alberta , Canada ,

Siddhartha Das , Micro and Nano-scale Transport Laboratory Department of Mechanical Engineering University of Alberta , Canada ,

Sushanta Kumar Mitra , Micro and Nano-scale Transport Laboratory Department of Mechanical Engineering University of Alberta , Canada.

One of the major factors that affect the dynamics of an evaporating drop is the instantaneous topography of the contact line and the flow field in its vicinity. In this study we employ Micro Particle Image Velocimetry (µ-PIV) to observe the flow field near the contact line in an evaporating drop under different system conditions, and delineate the unique flow characteristics at the contact line that dictate the contact line singularities quintessential in describing an evaporating drop.

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Chemical Trapping in Surfactants with Amino Acid Headgroups. Developing Protocols for Chemical Determination of Protein Topologies at Membrane Interfaces ,

Laurence Romsted , Rutgers, The State University of New Jersey , United States ,

Yongliang Zhang , Rutgers, The State University of New Jersey , United States.

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136 ,

Study of dynamic interfacial tension of sodium octyl benzenesulfonate at the water/hexane interface ,

Juan Pereira , University of Carabobo , Venezuela ,

Victor Coronel , VENOCO , Venezuela ,

Marceli Sanchez , VENOCO , Venezuela ,

Deynis Quevedo , VENOCO , Venezuela ,

Reinhard Miller , Max Planck Institute of Colloids and Interfaces , Germany ,

Aliyar Javadi , Max Planck Institute of Colloids and Interfaces , Venezuela.

Linear alkyl benzene sulfonates (ABS) are an important class of commercial surfactants, used in many industrial applications1. There is an important correlation between the surfactant structure and its adsorption behavior. The formation of micelles, aggregation in bulk and liquids crystals, are also subjects of interest. These behaviors are important from a practical perspective, as the ability of surfactants to reduce interfacial tension is often the key parameter to their performance. The ABS used in this work was synthesized from olefins linear of high purity. Using the drop Profile Analysis Tensiometer PAT -1 (SINTERFACE Technologies Berlin, Germany), dynamic interfacial tensions were measured for an anionic surfactant at the water-hexane interface. Experimental data obtained with constant surface area are advantageous for a quantitative data analysis. Typically, only the adsorption time and the interfacial tension are needed, sometimes, however, also the interfacial tension response due caused by drop area and volume changes with time are essential. Two samples of the surfactants sodium octyl benzenesulfonate NaC14H23SO3 (MW= 260.63 g/mol) from Aldrich, also synthesised in VENOCO industries and respectively re-crystallized, were studied. All experiments were performed at room temperature of 22 ◦C. Before doing the experiment hexane was saturated with the respective surfactant

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solution for 5 h and then the bulk phases separated for the measurements. This protocol is typical for studies at water/oil interfaces because surfactant can be soluble in both phases and this time is enough to transfer from one phase to another to establish the distribution equilibrium. Equilibrium interfacial tension values reported in terms of an isotherms, have been measured after a sufficient adsorption time to reach plateau values. This adsorption time depends on the surfactant concentration and was 1 h for the highest concentrations close to the CMC and 6 h for the lowest concentrations. The interfacial tension isotherms are described by thermodynamic models for single surfactants which allow consideration of different adsorption models2. The experimental data are very well described by the model and the resulting characteristic parameters are discussed. References 1. J.-G. Ma, B. J. Boyd, C. J. Drummond, Langmuir 22 (2006) 8646-8654. 2. V.B. Fainerman, E.V. Aksenenko, S.V. Lylyk, J.T. Petkov, J. Yorke, R. Miller, Langmuir 26 (2010) 284–292.

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Thermodynamics Insight into Surfactant Supported Ultrafiltration of Wastewater ,

Sakhawat Shah , Hazara University Mansehra, Khyber Pakhtunkhwa , Pakistan ,

Muhammad Arshad Khosa , Quaid-i-Azam University Islamabad , Pakistan.

Surfactants have property to form micelles when their concentration in aqueous solution goes beyond the critical micelle concentration (CMC). At this concentration, Stern layer of micelles attracts oppositely charged metal ions on the surface by columbic force. In addition, the organic colored dyes accumulate in the core of micelles through hydrophobic-hydrophobic interaction. This principle of micellization was employed to remove zinc ions and few organic dyes in our study. Methylene Blue (MB) and Reactive Black 5 (RB5) dyes were removed with help of oppositely charged surfactants SDS and CTAB; whereas, simultaneous separation of Alizarin Red S (ARS) and zinc ions from aqueous solution was carried out by using the idea of chelation and micellization. Thermodynamics of micellar enhanced ultrafiltration (MEUF) was discussed and thereafter, physical parameters such as rejection percentage and permeate flux that control the separation process, were determined during this study by using the membranes of variable pore size.

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The Rheology of Water-in-Oil Emulsions and the Relationship to Emulsion Stability ,

Merv Fingas , Spill Science , Canada ,

Ben Fieldhouse , Environment Canada , Canada.

Fifteen years of studies on the stability of water-in-oil emulsions have yielded extensive data on water-in-oil emulsions. The key measurement parameter has been found to be the rheology of the resulting water-in-oil product. The rheological data from a series of stress experiments were used to create stability indices for the emulsions. A stress sweep from 100 to 10,000mPa at a frequency of one reciprocal second was performed on more than 400 water-in-oil emulsion samples. The rheological properties are reported for the linear viscoelastic range. The viscoelastic properties have been found to discriminate in the types of water-in-oil emulsions. Particularly, the ratio of the elastic and viscous components of the complex modulus can be used as a discrimination parameter. It has been found that emulsions can be grouped into three categories: stable, unstable and meso-stable. Each of these has distinct physical properties. For example, the viscosity of a stable emulsion at a shear rate of one reciprocal second is at least three

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orders-of-magnitude greater than that of the starting oil. An unstable emulsion usually has a viscosity no more than two orders-of-magnitude greater than that of the starting oil. The zero-shear-rate viscosity is at least six orders-of-magnitude greater than the starting oil for a stable emulsion. For an unstable emulsion, it is usually less than two or three orders-of-magnitude greater than the viscosity of the starting oil. And finally, a stable emulsion has a significant elasticity, whereas an unstable emulsion does not. The stability of emulsions has been studied by examining their asphaltene content and secondarily, their resin content. Results are reported showing that asphaltenes and resins are responsible for stability. It is also shown that the content of other materials such as waxes is irrelevant to the basic formation process. The stability of any emulsion can be predicted by its asphaltene content and, to a secondary degree, by its resin content. It is noted that given the correct chemical composition, primarily asphaltenes, a minimum of sea energy is needed. The composition is related to the rheological properties of the emulsion after formation.

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Surface rheology of layers at the surface of water ,

Gabriel Espinosa , University Morelia , Mexico ,

Laura Arriaga , University Harvard , United States ,

Francisco Monroy , Universidad Complutense de Madrid , Spain ,

Dominique Langevin , Universite Paris Sud 11 , France.

In many circumstances, the interfacial dynamics of liquid-gas or liquid-liquid systems is analysed considering the surface tension only. It is however clear that other parameters play a role, such as surface elasticity and viscosity. The correct analysis is difficult. First there are two couples of surface parameters, one for compression and one for shear. Second, the viscoelastic surface parameters frequently depend on frequency and on the amplitude of deformation. As a result, the analysis of the interfacial dynamics requires an extensive experimental study of surface rheology. Despite these difficulties, surface rheology is increasingly investigated nowadays, due to the availability of new commercial instruments, based on oscillating bubbles/drops or making use of accessories of standard bulk rheometers (bicone, du Nouy rings). In this presentation, we will give examples of determinations of surface viscoelastic properties first for adsorbed surfactant monolayers and then for more complex layers : lipid monolayers, mixture of surfactants (lipids) and polymers, nanoparticles. We will present in particular data on shear rheology of monolayers of nanoparticles and of mixed layers made with DNA and surfactant on water. The data are strickingly similar to those for 3D soft solids such as foams, concentrated emulsions or dense colloidal dispersions. Depending on the compaction degree, the layers can behave as brittle or plastic solids. If time permits, we will show data on polymer monolayers on water, where a glass transition has been evidenced, the glass transition temperature Tg being smaller than the bulk value.

141 ,

Microemulsion Flow in Porous Medium for Enhanced Oil Recovery ,

Vanessa Santanna , Federal University of Rio Grande do Norte , Brazil ,



Ana Cristina Silva , Federal University of Bahia , Brazil ,

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Horacimone Lopes , Federal University of Bahia , Brazil ,

Francisco Sampaio Neto , Federal University of Bahia , Brazil.

Injection of microemulsion is a chemical technique of enhanced petroleum recovery. With the implementation of this technique, oil recovery is enhanced by increasing the viscosity of the microemulsion systems, and reducing the interfacial tension between oil and water in a porous medium. In this work, injection assays have been carried out with fluids comprising microemulsion-based commercial anionic surfactants, oil from the Quiambina Field (mature field in the Brazilian State of Bahia) and brine (2 % KCl). The experiments basically consisted on the injection of fluids into cylindrical plug samples from the Botucatu formation by means of conventional (injection of water or brine) and enhanced (injection of microemulsion) recovery techniques. During water and microemulsion flooding, samples were collected as a function of time, after which the volume of oil recovered was obtained. Parameters like mobility ratio, volume of displaceable oil, volume of displaced oil and displacement efficiency have been obtained as results. It was verified that lower mobility ratios were acquired with the injection of microemulsion than with injection of water, thereby favoring oil recovery. The volume of oil displaced by the microemulsion corresponded to 75 % of the total displaceable oil, which is a much higher yield than that observed in conventional recovery procedures. The results showed that, when microemulsion flooding is applied, the displacement efficiency is 21.5 %, whereas with the conventional method the efficiency is 41 %. It could be concluded that the use of microemulsion in enhanced oil recovery is efficient to provide higher levels of extraction due to the higher viscosity of the microemulsion and to the decrease in the interfacial tension between the fluids in the porous medium.

142 ,

Study Of The Properties of Foam of Sodium Octyl Benzenesulfonate, Sodium Decyl Benzenesulfonate and Sodium Dodecylsulfate ,

Victor Coronel , Industrias VENOCO , Venezuela ,

Marceli Sanchez , Industrias VENOCO , Venezuela ,

Juan C. Pereira , Universidad de Carabobo , Venezuela.

The Alkyl Benzene Sulfonates (ABS) represents an important volume of the consumption of anionic surfactants world wide, they are used in several industrial, cosmetics, domestic and many other applications, to know their behavior is essential to define the field of application, in this sense; the properties of foamability represent a parameter very important of such conduct. A comparative study of the dynamic behavior of aqueous solutions of Sodium Octylbenzene sulfonate (OBSS 97.70%) and sodium Decylbenzene sulfonate (DBSS, 80.41%) obtained industrially from Industrias VENOCO, and sodium dodecyl sulfate (SDS 99,00%) grade reagent from Sigma Aldrich, is conducted using a methodology developed to measure the foaming characteristic based on the theories of Bikerman 1953, Breul 1987 [1] and using as references Lunkenheimer 2003 [2] and the standard ASTM D 1881-1997 [3] .The method consists to blown an a portion of the solution at 25 C with air at a constant rate of 300 cc/min for 5 minutes through a spherical standardize gas diffuser stone. During the test, the volume of foam is recorded every one minute, until reaching the 5 minutes, at the end of this period the air flow is shut off and the volume of foam recorded immediately, this volume represents the foaming tendency (VfE). Continue recording the foam volume every ten minutes for 60 minutes, the volume of foam remnant at the end of this period represent the stability of the foam (VeE). These measurements provide also some features of the foams which we defined as a: speed of formation (υE), density of the foam (ρE) and factor of foamability of the surfactant (FES). The solutions of surfactant were prepared at different concentrations: below, at, and above the value of the critical micelle concentration (CMC) to evaluate the variation of foamability with the CMC. All the evaluation was performed according to the developed

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methodology. The experimental data are very well described and the resulting characteristic parameters are discussed.

143 ,

Harnessing Kinetics to Estimate Antioxidant Distributions in Emulsions Composed of Cationic and Anionic Surfactants and Demonstrate a Surprisingly Modest Sensitivity of Observed Rate Constants on Emulsion Droplet Size from Nano to Micro. ,

Laurence Romsted , Rutgers, The State University of New Jersey , United States ,

Qing Gu , Rutgers, The State University of New Jersey , United States.

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144 ,

Role Of Surfactants in Water-Proofing Of Buildings, Making Better Roads, Reducing Water Loss From Soil and Enhancing Plant Growth ,

Dinesh O. Shah , Shah-Schulman Center for Surface Science and Nanotechnology, Dharmsinh Desai University, Nadiad, Gujarat , India ,

Prakash Mehta , Zydex Industries, Vadodara, Gujarat , India ,

Ajay Ranka , Zydex industries, Vadodara, Gujarat , India ,

Bharat Gupta , DDU, Chem Engg Dept, Nadiad, Gujarat , India ,

R. S. Fougat , AUA, Anand, Gujarat , India.

Organosilicon compounds containing alkyl groups can react with –OH groups on the surface of sand, clay, soil, concrete, plaster or bricks. This reaction will add a monolayer of alkyl groups on the surface rendering the surface hydrophobic or water repellent. Such a monolayer chemically bonded with the surface will be stable for 25 to 30 years under normal environmental conditions. Such films can be used for water proofing of buildings, can be used for compaction of soil and preventing clay swelling, or water penetration under roads. It can be used to improve adhesion of asphalt with the aggregate surface if the aggregates have been treated with such organosilicone compounds with alkyl chains. In general, agricultural soil surfaces being hydrophilic in nature get easily wetted by water. The water beneath the soil moves through capillary effect and comes to the surface of the soil and thereafter evaporates into the surrounding air due to atmospheric conditions such as Sunlight, wind current, temperature and relative humidity. In countries depending entirely on rain water for its agricultural crops, often the seeds are planted by the farmers after first rain but if the second rain does not come in a timely manner then saplings die without additional water as most water from the soil evaporates during this time and hence the farmer has to replant the seeds resulting into financial burden on the farmers and more labor. To lower the water loss from soil, an experiment was designed in which a layer of hydrophobic soil was laid on the surface of ordinary hydrophilic soil. The top soil was made hydrophobic by treating with organosilicone surfactants which makes the soil permanently hydrophobic. This presumably pushes the menisci deeper into the soil away from the top surface. This technique strikingly decreased loss of water from the soil. The results indicated that the evaporation rate significantly decreased and 90% of water was retained in the soil in 83Hrs/3.5days by the hydrophobic soil layer of 2cm thickness without influencing oxygen transport into the soil. A greater retention of water in the soil by this approach can promote the growth of plants, which was confirmed by growing chick pea (Cicer arietinum) plants and it was found that the length of roots, height of shoot, number of branches, number of leaves, number of secondary roots, biomass etc. were significantly increased upon covering the surface with hydrophobic soil in comparison to uncovered ordinary hydrophilic soil of identical depth. This approach can decrease the water consumption by the plants particularly grown indoors in residential premises, green houses and poly-houses etc. This approach can be very useful to prevent water loss and enhance growth of vegetation in semi-arid regions This approach can be extended to developing the hydrophobic coatings that can be biodegraded in four to eight weeks and hence leave the surface unaltered for the next rainy season to absorb the water. However, such coatings can save the water for the very crucial period of four to six weeks after planting the seeds. The topology of the soil can be engineered (five-spot pattern) such that rain water can drain into the foot prints of the plants or fruit trees like lemon and oranges. Conceptually, this approach will involve spraying the solution of biodegradable de-wetting agents or surfactants after planting the seeds that would make the soil particles hydrophobic for a few weeks and also reduce the evaporation rate of water from soil by pushing menisci away from the surface deeper into the soil. This approach of saving water in the soil can substantially improve the crop productivity.

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145 ,

Sensitivity Enhancement of Quenchofluorimetric Methods for the Determination of Selected Analytes via Micellar Amplification ,

Aamna Balouch , National Centre of Excellence in Analytical Chemistry, University of Sindh , Pakistan ,

Willie L Hinze , Department of Chemistry, Salem Hall, Wake Forest University , United States.

The feasibility of utilizing surfactant micelles to enhance the dynamic quenching observed between anions (as well as one cation and one neutral organic molecule) and different fluorescent probe molecules were examined. Namely, the fluorescence intensity observed from such aromatic molecules as fluoranthene, naphthalene, anthracene, lucigenin, N- methylacridone, acridine and 3-aminophthalate in aqueous solution and in micelle solution in the absence and then presence of different anions (or other analytes) was determined as a function of the analyte ion. It was found that if the fluorescent probe molecules are in a cationic micelle, then anions are attracted to the cationic micelle surface and their quenching effect if magnified relative to that observed in water alone in the absence of micelles. Thus, cationic micelles were used to enhance the fluorescence quenching effect of anions. The corresponding Stern-Volmer quenching plots serve as a means of calibration. The effect of variation of the different experimental factors (the nature of the fluorescent probe molecule, type of surfactant and its concentration and analyte ion concentration) were evaluated. Using such approach under optimized conditions, the detection limits observed for the other ions examined were lower in the cationic micelle system relative to water. Thus, the presence of the micelle enhances the sensitivity of this quenching method by over an order of magnitude.. This work demonstrated that simple noncovalent quenching can be employed to determine anions or cations provided the proper micelle forming surfactant is selected.

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Is kinetics of micelles related to miceller catalysis? ,

Manu Vashishtha , Shah-Schulman Center for Surface Science and Nanotechnology, Faculty of Technology, Dharmsinh Desai University, College Road, Nadiad ‚Äì 387 001, Gujarat, India , India ,

Manish Mishra , Shah-Schulman Center for Surface Science and Nanotechnology, Faculty of Technology, Dharmsinh Desai University, College Road, Nadiad ‚Äì 387 001, Gujarat, India , India ,

Dinesh Shah , Department of Chemical Engineering and Department of Anesthesiology, University of Florida, Gainesville, Florida, USA.

The effect of micellar stability or kinetics on miceller catalysis was studied on base (NaOH) catalysed cross aldol condensation of benzaldehyde (1) and cyclohexanone (2) to α,ά-bis (benzylidene) cyclohexanone (3) as model reaction (Scheme 1) in aqueous miceller solutions of cationic surfactants. The pure quaternary ammonium surfactants (QAS; having C10, C12, C14, C16 and C18 alkyl substituents) and the mixed QAS solutions (with 10 mol% of different fatty alcohols; C10 to C18 alcohols) as well as alkyl (C12 and C16) pyridinium salts aqueous solutions were used as reaction medium to study the influence of stability of micelles on the miceller catalysis. It was found that the stable micelles produced by higher QAS (C16 and C18) in pure form as well as their mixed form with C16 and C18 alcohols gave highest yield (>95%) of desired product (3) with negligible amount of monocondensation by-product (4) with faster reaction rate in comparison of less stable micelles of lower QAS, mixed micelles of higher QAS (C16 and C18) with lower fatty alcohols and alkyl (C12 and C16) pyridinium surfactants solutions. It was observed that stable micelles produce selectively α,ά-bis (benzylidene) cyclohexanone (3) whereas less stable micelles reduce the yield of the desired product (3) giving monocondensation product (4) as major product. We did not

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observe the formation of self condensation product from cyclohexanone, which shows that miceller catalysis selectively catalyze the cross aldol condensation.

147 ,

Phase Characteristics of Langmuir Monolayers ,

Dieter Vollhardt , Max Planck Institute of Colloids and Interfaces , Germany.

Rapid progress in understanding the molecular organization of condensed monolayer phases is demonstrated. The combination of Π-A isotherms with mesoscopic BAM imaging and GIXD information about the 2D lattice structure is optimal for the experimental phase characterization of amphiphilic monolayers. The development of new equations of state allows the theoretical description of the fluid/condensed phase transition region decisive for the features of the monolayer.

New mesoscopic length scale characteristics of monolayer material are available, such as morphology and textural features of the domains, equilibrium and non-equilibrium states, chiral discrimination effects, molecular recognition of non-surface active species dissolved in the aqueous subphase. An unsuspected morphological variety of condensed phase domains has been found that were formed in Langmuir monolayers and in adequate molecular recognition systems. In all these systems, shape and size of the monolayer domains as well as their textural features depend sensitively on the chemical structure of the amphiphiles and the monolayer state determined mainly by surface pressure and temperature. The inner textures of domains can be explained by consideration of their geometry and lattice in dependence of the tilt angle of the alkyl chains and can be described by a geometric concept on the basis of the molecular packing.

The high sensitivity of the morphological features of the condensed phase domains to the specific stereochemistry has been visualized by impressive chiral discrimination effects. Both homo- and heterochiral preference for chiral interaction has been observed depending on the intermolecular interaction of the amphiphilic molecules.

Molecular recognition at the air-water interface by assembly between monolayer components and guest materials dissolved in the aqueous subphase is one of the most important research topics in this field. At interfacial molecular recognition the Langmuir monolayer formed by receptor molecules binds non-surface-active target molecules dissolved in the aqueous subphase by complementary hydrogen bonding or/and acid–base interaction.

148 ,

New insight into colloid-solvent interactions analyzed by Thermal field-flow fractionation ,

Kyriakos Alexandros Eslahian , BAM Federal Institute for Materials Research and Testing , Germany ,

Michael Maskos , Institut fur Mikrotechnik Mainz , Germany.

Chemical and physical properties of colloids in aqueous dispersions are dominated by their surface properties caused by the large surface to mass ratio. Investigation of interactions at the particle-solvent interface provides information about the particle surface. In addition, slight variations of the particle-solvent interface generate substantial alteration of thermophoresis, which itself is still a not completely understood phenomenon[1]. This phenomenon is studied in thermal field-flow fractionation (ThFFF), a quasi-chromatographic technique to fractionate colloids with respect to their thermophoretic mobility[2].

We present the influence of zeta potential and type of electrolyte on retention behavior in ThFFF[3]. A relation to theoretical models of thermophoresis is revealed by observation of thermoelectric effects. The

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capability of ThFFF to separate particles with equal hydrodynamic size, as determined by dynamic light scattering (DLS) and asymmetrical flow field-flow fractionation (AF-FFF), is demonstrated. In addition, we discuss the potential to determine particle surface properties by thermophoretical investigations.

Reference:

[1] A. Wurger, Rep. Prog. Phys. 2010, 73, 126601. [2] S. J. Jeon, M. E. Schimpf, A. Nyborg, Anal. Chem. 1997, 69, 3442. [3] K. A. Eslahian, M. Maskos, Colloids and Surfaces A: Physicochemical and Engineering Aspects 2012, 10.1016/j.colsurfa.2012.02.003.

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Superhydrophobic surfaces with multiscale roughness made from raspberry particles ,

Lena Mammen , Max Planck Institute for Polymer Research , Germany ,

Xu Deng , Max Planck Institute for Polymer Research , Germany ,

Maria D'Acunzi , Max Planck Institute for Polymer Research , Germany ,

Doris Vollmer , Max Planck Institute for Polymer Research , Germany.

Superhydrophobicity requires roughness on the micro- and nanometer scale combined with a low-energy surface. Our superhydrophobic surfaces consist of raspberry-like particles that are micrometer sized polystyrene colloids covered with a rough silica shell [1]. Films are prepared by dip-coating or solvent evaporation. After silanization with a semi-fluorinated silane the films show static contact angles for water above 160° and roll-off angles below 5°. Mechanical stability is induced by chemical vapour deposition of tetraethoxysilane (TES) to create silica bridges between neighboring particles (Fig. 1. A) as well as between the particles and the substrate [2]. Besides, silica synthesis from TES vapour leads to the formation of covalently bonded 5-20 nm sized silica hemispheres (Fig. 1. B). Their size can be tuned by the duration of chemical vapour deposition. This hemispherical nano-roughness reduces the pinning sides and improves the sliding angles. Also polymer lattices such as polystyrene (PS) or polymethylmethacrylate (PMMA) particles (Fig. 1. C) or can be decorated with silica hemispheres. Therefore we report a general method to tune the nanoscale roughness of a surface. Figure 1. A) Neighboring raspberry particles connected by a silica bridge (TEM image). B) Raspberry particle and C) PMMA particles are decorated with small silica hemispheres after 24 h chemical vapour deposition of TES (SEM images).

Reference:

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[1] M. D’Acunzi, L. Mammen, M. Singh, X. Deng, M. Roth, G. Auernhammer, H.-J. Butt and D. Vollmer: Superhydrophobic surfaces by hybrid raspberry-like particles, Faraday Discuss. 2010, 146, 35. [2] X. Deng, L. Mammen, Y. Zhao, P. Lellig, K. Müllen, C. Li, H.-J. Butt, and D. Vollmer: Transparent, thermally stable and mechanically robust superhydrophobic surfaces made from porous silica capsules, Adv. Mat. 2011, 23, 2962.

150 ,

Transparent silica nano- and microchannels for microfluidic devices ,

Lena Mammen , Max Planck Institute for Polymer Research , Germany ,

Xu Deng , Max Planck Institute for Polymer Research , Germany ,

Kathrin Friedemann , Max Planck Institute for Polymer Research , Germany ,

Daniel Crespy , Max Planck Institute for Polymer Research , Germany ,

Periklis Papadopoulos , Max Planck Institute for Polymer Research , Germany ,

Hans-Jurgen Butt , Max Planck Institute for Polymer Research , Germany ,

Doris Vollmer , Max Planck Institute for Polymer Research , Germany.

Nano- and microchannels are attractive model systems for fundamental studies like filling kinetics [1,2], diffusion processes or transport phenomena. In this work transparent nano- and micrometer-sized silica channels were prepared by coating different polymer fiber templates with silica performing a modified St√∂ber synthesis and subsequent removal of the organic material by calcination. As templates either polystyrene electrospun or spider silk fibers were used. The channels have a spherical cross section with uniform diameter and smooth surface. We measured the capillary filling speed of water and glycerol/water mixtures using laser scanning confocal microscopy (LSCM) what is a convenient technique to observe the filling velocities close to the channel entrance. By comparing our results with the theoretically predicted values according to the classical Washburn kinetics [3] we found a deviation for small filling times (< 0.1 s) from the power law.

Figure: Top: transparent micrometer-sized silica channel with spherical cross section and uniform diameter; Bottom: LSCM image of a channel filled with a dyed glycerol/water mixture (80 % v/v glycerol).

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Reference(s) [1] A. Han et al., J Colloid Interf Sci, 293, 151 (2006) [2] N. Tas et al., Appl Phys Lett, 85, 3274 (2004) [3] E. W. Washburn, Phys Rev, 17, 273 (1921)

151 ,

The Influence of molecular interactions on foaming properties from surfactant systems ,

Gabriela Camacaro , University of Carabobo , Venezuela ,

Victor Perez , University of Carabobo , Venezuela ,

Juan Pereira , University of Carabobo , Venezuela.

Foams occur as end products or during the processing of products in a wide range of areas including the paints, detergent, food, cosmetic and petroleum industries. Stability of foams can play an important role in scientific and practical applications. Surfactants molecules cover the air/liquid interfaces to prevent collapse of the foam, are generally effective in increasing the foam stability1. The relationship between the phase behavior of equilibrated surfactant-oil-water (SOW) systems and dynamic surfactants systems, like emulsions and foams, attained upon stirring has been established a lot of years ago and has been corroborated for many different systems since then2. This research is aimed towards understanding effect of the formulation variables of surfactant-oil-water systems on the dynamical properties of foams. The study of the foaming properties was carried out on the aqueous phases formulated systems. The surfactants used were: SDS (sodium dodecyl sulfate), SDBS (sodium dodecyl benzenesulfonate) and NPEs (nonylphenol ethoxylates) with EON (ethylene oxide number), between 4 and 20 moles. The aqueous phase used was sodium chloride solution and Kerosene as oil phase. The optimal formulation was reached for three-phase systems of volumes of oil and aqueous phase were equal. Here, was used the water to-oil ratio (WOR) equal to unity. Then, the aqueous phases of these systems were tested for foamability by mechanical agitation and Ross-Miles methods. Preliminary results show a decreasing trend for the foamability in biphasic systems with increasing salinity and approach the optimal formulation. It was found that when the water to-oil ratio (WOR) is near unity, dynamic surfactant systems type essentially depends on the physicochemical formulation2. By contrast, in biphasic systems, above the optimum formulation is a trend to decrease the foamability. The results obtained suggest that the molecular interactions of surfactant influence the properties of the foam. The salt concentration in the aqueous phase modifying the hydrophilicity of the surfactant. Then, it is intended to establish a correlation between the formulation of surfactant-oil-water systems and its foaming properties.

Reference

1. R.J. Pugh. Foaming, foam films, antifoaming and defoaming. Adv. Colloid Interface Sci. 64 (1996) 67‚Äì142.

2. J-L. Salager, N. Moreno, R. Ant√≥n, and S. Marfisi. Apparent Equilibration Time Required for a Surfactant-Oil-Water System to Emulsify into the Morphology Imposed by the Formulation. Langmuir 18 (2002) 607-611.

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152 ,

Controlling emulsion stability by using charged silica nano-particles ,

Glenda Noboa , Universidad de Los Andes , Venezuela ,

Laura Marquez , Universidad de Los Andes , Venezuela ,

Juan Lopez , Universidad de Los Andes , Venezuela.

In this research we found how silica nano-particles can be used to control emulsion stability. Emulsions were mechanically formed, using three different surfactants, anionic, cationic and non-ionic, all of them with lauryl tail. Silica particles and different HCl volumes were added to some of those emulsions. The stability was monitored by measuring mean drop size and aqueous phase level. Results shows that interaction between particle presence-HCl volume factors destabilize emulsions formed with anionic surfactant, stabilize those formed with cationic and does not affect those formed with non-ionic surfactant. A mass transfer, at molecular-microscopic level, mechanism explains quite well how the observed emulsion destabilization phenomenon works.

153 ,

Formulation of Surfactant-Oil-Water (Sow) Systems for the Removal of Petroleum Contaminated Soils. Effect of Different Alcohols ,

Ana Garcia , University of Carabobo , Venezuela ,

Yoleida Navarro , University of Carabobo , Venezuela ,

Victor Perez , University of Carabobo , Venezuela , Juan Pereira , University of Carabobo , Venezuela.

Contamination of soil with hydrocarbons is a serious problem and is spread all over the world. Oil spills may cause severe environmental impacts and remediation procedures are necessary to restore soil quality. Surfactants solutions have been used by the petroleum industry to increase oil recovery in reservoirs. The use of such fluids for the remediation of contaminated soils has been investigated by many authors. In the present study was evaluated the influence of different alcohols on the Surfactants-Oil-Water systems (SOW) for use in removing oil from contaminated soils. Usually these systems are formulated with alcohols, which have a double function: on the one hand act as co-surfactants, reducing or eliminating the structures of gels or liquid crystals tend to form pure the surfactants, and on the other, co-solvents having influence on the balance of affinity between the surfactant and physicochemical environment. In this study, formulated systems were developed with SDS (sodium dodecyl sulfate) 1% w/v, using a Kerosene as oil phase. the systems were formulated with respectively 5.2% v/v alcohol (1-pentanol, 1-butanol, 1 - hexanol, 1-propanol). The SOW systems evaluated were put in contact with the ground, shaking mechanically. Performance is achieved greater than 90% removal of total crude oil soil, the initial content of crude (10.0% w / w) determined previously in ours laboratory. The results were visually observed by comparing the soil treated with SOW, against the reference and polluted. Gravimetric analysis was performed to determine the system performance and confirmed by infrared spectroscopy technique, with which were characterized as well, the soil samples before and after treatment with SOW the systems.

The influence of the alcohols in formulated the systems, it is important to further knowledge in the application of the emulsions and microemulsions in order to achieve low interfacial tensions and high solubilization of oil contained in a solid substrate.

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The contribution of each alcohol was a function of chain length of the corresponding branching or any of its affinity for the aqueous or organic phases.

154 ,

Reverse Ostwald Ripening: A mass transfer mechanism which can be present during the first few minutes of foams life ,

Juan Lopez , Universidad de Los Andes , Venezuela ,

Liliana Fernandez , Universidad de Los Andes , Venezuela ,

Asdrubal Canache , Universidad de Los Andes , Venezuela.

In this research, foam stability was evaluated during the first 20 minutes by measuring foam level and by monitoring the pressure difference between two cells, one with foam and the reference with water. The experiments were carried out in a Nishioka Ross cell. Foams were formed with sodium dodecyl sulphate, SDS, in water at different concentrations. The results suggest that mass transfer occurs against the common intuition; mass flows from phases at “high pressure” to one at low pressure, we call this phenomenon as Reverse Ostwald Ripening.

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Wettability evaluation of reservoir rocks under ASP injection from different techniques: Amott-Harvey, RMN and XPS. ,

Daniela Rodriguez , Intevep - PDVSA , Venezuela ,

Alida Veliz , Intevep - PDVSA , Venezuela ,

Yefrenck Castro , Intevep - PDVSA , Venezuela.

The necessity of increasing heavy and extra heavy oil production and recovery efficiency has led to researching and development of new technologies, which will be applied in fields that have been exploited through secondary recovery schemes by waterflooding or gas injection. It is justified because approximately 80% of the oil in place remains trapped inside the reservoir due to several factors, such as adverse conditions of wettability and capillary forces among others. Nowadays, a great importance has been given to the recovery of this kind of oil by presenting new recovery methods that has proven drastic interfacial tension reduction, during chemical injection. In this research, laboratory studies of phase behavior and interfacial tension were carried out at reservoir temperature for different ASP formulations, to define its optimal concentration able increase the recovery factor. This kind of process alters the wet condition of the rock surface. The objective of this research is to evaluate the wettability changes of rocks surface from different Venezuelan oil reservoirs by using three different techniques: Amott-Harvey, NMR (Nuclear Magnetic Resonance) and XPS (X-ray Photoelectron Spectroscopy) that occur when they are subjected to injection of alkali-surfactant-polymer (ASP) mixtures as a recovery strategy that maximizes the oil recovery factor. From the techniques evaluated it was found that XPS is the most efficient and fastest method to predict wettability changes, whereupon it was found that the ASP optimal formulation changes the core wet condition. Finally, it was confirmed through displacement tests at reservoir conditions (P and T) that the ASP optimized formulation changes the wettability of the rock surface, making it not to have preference for any particular fluid (intermediate wetting), and achieves an increase in the oil recovery of about 20% after injecting of the ASP formulation.

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156 ,

Salt-free catanionic surfactants in water: role of chain-length mismatch on multifaceted aggregation behavior ,

Eduardo Marques , University of Porto , Portugal.

Swelling bilayer-forming amphiphiles are relevant materials inter alia for the building of biomimetic membrane systems and the formulation of microemulsions, multilayered films, nanoreactors and molecular transporters. If these molecules also show some type of stimuliresponsive aggregation, further practical relevance is added, e.g. in the rheological control of colloidal materials. Salt-free catanionic surfactants, or ion-paired amphiphiles, are complex salts of the Cm +Cn - type, where the two amphiphilic ions of opposite charge act as counterions to each other [1-3]. They are a versatile class of swelling compounds, with their self-assembly being easily tunable by the choice of molecular structure, and variables such as temperature and ionic strength. In this talk, we will address recent investigations on the aqueous phase behavior and microstructure of a series of salt-free catanionics with varying chain length mismatch, m ≠ n [3-5]. Compared to the more general catanionic mixtures (Cm+X-/ Cn-Y+/water systems), these compounds have neither inorganic salt present nor excess of ionic amphiphile. Thus, any surface charge density (σ) on the catanionic film will arise solely from differences in the individual solubilities of the two ions, leading to long screening lengths and modulations of spontaneous curvature [3].

This solubility mismatch results in some peculiar features of aggregation, including the coexistence of lamellar phases, intermediate phase formation, temperature-dependent vesicle-to-micelle transitions, fusion and fission of bilayers and (in ternary systems) to microemulsion formation [3-5]. For instance, on the dilute region of the binary phase diagrams, spontaneous formation of vesicles is observed for most of the systems, and interestingly many of these vesicles undergo a (reversible) transition to elongated micelles with temperature, via a bilayer fusion-fission mechanism.

Reference: [1] T Zemb, M Dubois, Aust. J. Chem. 2003, 56, 971. [2] JC Hao, H Hoffmann, Cur. Op. Colloid Interface Sci. 2004, 9, 279. [3] BFB Silva, EF Marques, P Linse, U Olsson, J. Phys. Chem. B 2009, 113, 10230. [4] BFB Silva, EF Marques, U Olsson, R Pons, Langmuir 2010, 26, 3058. [5] BFB Silva, EF Marques, U Olsson, Soft Matter 2011, 7, 225.

157 ,

Fixing of gathering dust surface of the Aral Sea by interpolymer complexes of polyethylenimine ,

Neyla Bekturganova , Kazakh National Technical University after K.I.Satpaev , Kazakhstan ,



Moldir Kerimkulova , Al-Faraby Kazakh National University , Kazakhstan.

Now it is known, that the extensive areas of naked sea-bottom of Aral are covered by adjournment of the marine salt mixed with mineral fertilizers and other toxic compounds. Carried away by wind and water, this poisonous dust is transferred on hundreds kilometers. Inhalation of a poisonous dust undermines health of the person, reduces of immunity, leads to allergic and many other diseases.

Desiccation of the Aral Sea has also lead to some change of a local climate. During the past years the Aral climate has been changed from Continental. At that moment the measures undertaken by the scientists and different organizations to improve of ecological condition of the Aral region are not able to stop

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global ecological accidents. Therefore the urgency of research and elimination of the problem do not cause doubts. From our points of view, carrying out complex researches including structurization of soil by fixing of its superficial layer to prevent the land from erosion process and to improve of ecological condition such as reduction of negative influence on –∞ero- and hydrosphere of eroded soil is needed.

The main goal of the present work to determinate regularities of structurization of eroded soils of Aral Sea by polyethylenimine and its composion with sodium humate. The concept about soil as about disperse system with complex microheterogeneous structure allows to apply regularities of physical and chemical mechanics to processes of structurization of soil dispersions. In the given work the wind erosion is simulated as a set of the interconnected processes of separation, carrying and depositing of soil particles by wind. Previously we investigated the optical density, viscosity, electrokinetic potential and the plastic strength of soil suspension. Such correlation of physical and chemical parameters has allowed to use the given polymers and their interpolymer complexes (IPC) to increase antierosion stability of mineral dispersion.

The detected phenomena at studying of soil suspensions plastic strength have proved to use of IPC data for increasing of antierosion stability of soil suspension upon wind erosion. Growth of concentration and molar ratios of reagents leads to decreasing of deflation of soil particles. Intensity of polymers and IPC deflation is nearly 5-6 and 2-3 % respectively that testifies about formation of durable soil units.

Investigation of influence of IPC deposition method on soil surface has shown an insignificant difference in fixing of superficial layer. Amount of fixing at spraying of prepared IPC is 91,4-92,6%. Amount of fixing at consecutive deposition is 92,29-92,78% and is 92,31-92,77% at consecutive fixing. The difference in fixing of soil superficial layer is 1,4%.

It is established that the fixing of soil dispersion by IPC has been proceeded by the formation of associates stabilized by Coulomb and hydrophobic interactions, van der Waals forces, as well as coordination and hydrogen bonds. Fixing effect of IPC is reduced to electrostatic interactions with the soil surface, penetration into the interior of a polydisperse system and binding the soil colloids by hydrophobic interactions and hydrogen bonds. As a result the strong soil structure, which has good anti-erosion properties, has been formed.

158 ,

Molecular behavior of lubricants/additives under lubricating condition ,

Koji Miyake , AIST , Japan ,

Seiya Watanabe , Tokyo University of Science , Japan ,

Miki Nakano , AIST , Japan ,

Shinya Sasaki , Tokyo University of Science , Japan.

Fourier Transform Infrared Spectroscopy (FT-IR) equipped with pin-on-disk tribometer, which realizes the simultaneous measurement of friction force, normal load, and IR spectrum, was used for analyzing molecular behavior of lubricants/additives under lubricating condition, and sum frequency generation (SFG) spectroscopy was used to obtain static information on the molecular structure of the boundary layer. Self-assembled monolayers (SAMs) of hexadecanethiol (HDT) and 16-mercaptohexadecanoic acid (MHDA) were used to vary the surface chemical properties, and oleic acid (OA) was used as a lubricant in order to clarify the effect of surface chemical properties on the frictional property. In addition, we used 1-metyl-3-butylimidazolium trifluoromethanesulfonate ([BMIM]OTf) and 1-metyl-3-butylimidazolium tetrafluorophosphate ([BMIM]PF6) as lubricants in order to evaluated the influence of water on the tribo-chemical reaction of room-temperature ionic liquids (RTIFs). From the SFG and FT-IR results, the relationship between surface chemical properties and chemical properties of lubricants is considered to

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affect the boundary layer structures, and the difference in the interaction between the types of SAMs and lubricants is considered to affect the frictional properties of SAMs lubricated with each lubricant. Namely, the amount of water contained in RTILs as well as window material has a significant effect on the tribo-chemical reaction of RTILs.

159 ,

Pseudo-dewetting Driven Pillar Formation from Drying Polymer Droplets ,

Kyle Baldwin , Nottingham Trent University , United Kingdom ,

David Fairhurst , Nottingham Trent University , United Kingdom.

Unlike the familiar "ring-stain" formed when droplets of spilt coffee are left to dry, liquids containing high molecular weight polymer molecules leave a range of other deposit patterns. In particular, we observe that aqueous solutions of the common polymer poly(ethylene oxide)(PEO) dry to form a tall central pillar. We identify four stages in the drying process, including a pseudo-dewetting liquid stage which appears to be driven by the formation of solid precipitate at the 3 phase contact line. The growing solid deposit eventually lifts the droplet from the surface, resulting in the final central deposits. To investigate this phenomenon, we have varied experimental factors including: atmospheric temperature, humidity and pressure; molecular weight and concentration of the polymer solution; volume and contact angle of the initial droplet. We find a region in parameter-space for which the central pillars form, favouring fast drying conditions, high contact angle droplets, high conentration solutions and intermediate range of molecular weight. We show that a dimensionless Péclet-type number Pe, which compares the relative effects of evaporation and diffusion on the polymer motion, successfully predicts the final deposit shape. We attempt to incorporate the effect of molecular weight by considering molecular diffusion in the various concentration regimes known to exist in polymer solutions: from slow diffusion in semi-dilute solutions to faster network diffusion for entangled polymers.

160 ,

Self Assembled Monolayers: Fundamental Aspects and Applications to M/NEMS Technology ,

Roya Maboudian , University of California at Berkeley , United States ,

Carlo Carraro , University of California at Berkeley , United States.

Amphiphilic self-assembly has long been exploited to produce monolayer molecular films at the air-water interface and, more recently, on solid substrates (self-assembled monolayers, SAMs). A class of widely used SAMs is based on n-alkyltrichlorosilane precursor molecules, which, through hydrolysis and polymerization, produce self-assembled alkylsiloxane films on many hydrophilic substrates. In this talk, we will present an overview of what is known about the kinetics and dynamics of self-assembly process involved with this class of SAMs. The effects of temperature and surface roughness on the SAMs formation will also be discussed. In practical applications, SAMs must survive a variety of conditions, including high temperature and varied relative humidity. The effects of these parameters on SAMs stability will be addressed. Next we will turn to the application of SAMs as boundary lubricants and passivating coating in micro-/nanoelectromechanical systems (M/NEMS). Despite much progress in these technologies, adhesion, friction and wear (tribology) remain key issues, severely limiting the reliability of many M/NEMS devices. The various classes of SAMs explored for M/NEMS will be reviewed, along with a discussion of their current shortcomings.

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161 ,

Graphene@Mn3O4 Hybrid Composites for Supercapacitor Electrodes Application ,

Jeong Woo Lee , Korea Advanced Institute of Science and Technology (KAIST) , Korea, Republic Of ,

Jong-Duk Kim , Korea Advanced Institute of Science and Technology (KAIST) , Korea, Republic Of.

Graphene/Mn3O4 composites were prepared by a simple hydrothermal process from KMnO4 using ethylene glycol as a reducing agent. Mn3O4 nanorods of 100 nm‚Äí1 Œºm length were observed to be well dispersed on graphene sheets. To assess the properties of these materials for use in supercapacitors, cyclic voltammetry and galvanostatic charging-discharging measurements were performed. Graphene/Mn3O¬≠4 composites could be charged and discharged faster and had higher capacity than free Mn3O4 nanorods. The capacitance of the composites was 100 % retained after 10,000 cycles at a charging rate of 5 A/g.

162 ,

The Theory of Brownian Coagulation ,

Lee R. White , University of South Australia , Australia.

The theory of Brownian coagulation is 95 years old. In 1916, von Smoluchowski published his theory of rapid coagulation in which the rate of depletion of singlet particles in a dispersion that has been de-stabilised by the removal of repulsive barriers between the particles was calculated by considering the process as the mutual diffusion of the particles towards one another. The theory of slow Brownian coagulation was developed by Fuchs in 1934 and later by Vervey and Overbeek in 1948 in which the residual presence of a repulsive barrier to coagulation controlled the mutual diffusion process. The conventionally accepted theory of slow coagulation was developed following the suggestion of Derjaguin in 1966 that the rate of coagulation was significantly affected by the repulsive hydrodynamic drainage forces that each particle exerted on the other during the final stages of approach. This effect was variously treated by invoking the concept that the mutual diffusion coefficient is a strong function of particle separation in the close approach regime. The modern conventional theory relies on the attractive component of the inter-particle pair potential being infinitely attractive at contact to counter the infinite drag on two approaching particles there and thus ensuring the production of contact doublets. We examine the consequences of the attractive potential being finite at contact and construct a new theory of slow Brownian coagulation which attempts to account for the experimentally observed features of coagulation which are at variance with theoretical prediction. A simple result for the stability of suspensions is derived and discussed with some numerical predictions with respect to the peculiar insensitivity of coagulation rate with particle size observed experimentally.

163 ,

Synergism in Spreading of Hydrocarbon-Chain Surfactants on Highly Hydrophobic Surfaces ,

Yongfu Wu , Kemira R&D Centre , United States ,

Amir Mahmoudkhani , Kemira R&D Centre , United States ,

Mohan Nair , Kemira R&D Centre , United States.

Spreading of aqueous solutions on hydrophobic surfaces is important for applications ranging from the cleaning of greasy industrial and automotive equipment and parts to the washing of oil fume-covered automobile windshields, to the shampooing of body oil-coated hair, to the coating and printing operations on polyethylene and other hydrophobic plastics, to the spreading of insecticides and herbicides on plant

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leaves that generally are covered with a natural wax. The spreading ability of surfactant aqueous solution on a solid surface can be measured by the spreading factor, which is defined as the ratio of the spreading area of surfactant solution to the spreading area of the same volume of solvent under the same experimental conditions.

On highly hydrophobic surfaces, however, many hydrocarbon-chain surfactants are not suitable for this purpose, since their aqueous solutions do not spread well on these surfaces. In this presentation, results of our research of the spreading of aqueous solutions of some cationic, anionic hydrocarbon-chain surfactants and their mixtures will be presented. It has been found that certain mixtures of hydrocarbon-chain ionic surfactants have the ability to increase dramatically the spreading of their aqueous solution on hydrophobic surfaces, such as polyethylene and ParafilmÂ®. Aqueous solutions of the individual ionic surfactants investigated at concentration of 1.00 g/L do not spread at all on polyethylene film. When some of them are mixed properly at the same total concentration, the spreading factors can be increased dramatically, up to 400 times that of the individual surfactant solutions.

Therefore, a strong synergistic effect on the spreading of the mixed surfactant solution has been observed, which makes spreading of the conventional hydrocarbon-chain surfactants comparable to or even better than that of super-spreading normally obtainable from trisiloxane-based surfactants. It indicates that a strong attractive interaction exists between the surfactants at the interface of polyethylene and surfactant aqueous solution. In some cases, due in part to the incompatibility of these conventional surfactants, the cationic and anionic surfactants must be applied in a two-step procedure.

To date, various theories have been proposed to explain the super-spreading behavior of the surfactant aqueous solution on low-energy hydrophobic surfaces, a great deal of work has been done, and a considerable number of papers have been published. However, very few papers have been published related to the synergism in the spreading of aqueous solutions of hydrocarbon chain surfactants on hydrophobic. Consequently, the mechanism of such synergism is not yet understood. In this paper, a mechanism for this synergism of spreading is proposed.

164 ,

Application of Hydrophobically Modified Inulin Polymeric Surfactant for Stabilization of Emulsions, Nano-Emulsions and Latexes ,

Tharwat Tadros , 89 Nash Grove Lane Wokingham, Berkshire RG40 4HE, , United Kingdom.

Hydrophobically modified inulin (INUTEC SP1) is a graft copolymer consisting of inulin (linear polyfructose with degree of polymerization > 23) on which several alkyl (C12) chains are grafted. It is an excellent stabilizer for oil-in-water (O/W) emulsions and nano-emulsions as well as for latexes. The principles of stabilization of these disperse systems when using INUTEC SP1 are summarized : (i) Strong adsorption of the graft copolymer by multi-point attachments with several alkyl chains. (ii) Strongly hydrated loops and tails of polyfructose that provide effective steric stabilization. O/W emulsions with paraffinic or silicone oil as the disperse phase could be prepared using low levels of INUTEC SP1 (2% based on the oil phase). Emulsions were prepared both in aqueous media and solutions containing high electrolyte concentrations (> 2 mol dm-3 NaCl) and these emulsions showed no coalescence for a period of more than 1 year at 50oC. This high stability in high electrolyte concentrations and high temperature could be attributed to the strong hydration of the polyfrucose loops and tails. Evidence for this strong hydration was obtained from cloud point measurements. A strong evidence for the high stability of the emulsions was obtained from disjoining pressure measurements. The results showed the formation of a Newton black film that did not ruptures after application of a pressure in excess of 45 KPa. The same graft copolymer could be used to prepare nano-emulsions using high pressure homogenization. The results showed absence of Ostwald ripening (which is the main instability process of nano-emulsions) and plots of the cube of the radius versus time gave a very low Ostwald ripening rate when compared with nano-emulsions prepared using simple non-ionic surfactants of the ethoxylate type. This reduction in Ostwald ripening is due to the strong adsorption of the graft copolymer (and lack of desorption) as well as the high interfacial elasticity

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produced by the adsorbed polymer. The graft copolymer was also applied for the preparation of latexes of polystyrene, poly(methylmethacrylate) and poly(butyl/methacrylate). The most remarkable result was the low INUTEC SP1 concentration required for the preparation of the latexes by emulsion polymerization. The stability of the latex dispersions was determined by measuring the critical coagulation concentration (CCC) using CaCl2 as electrolyte. Evidence for the high stability of the latexes when using INUTEC SP1 was obtained using atomic force microscopy (AFM) measurements. For this purpose the interaction forces were measured between adsorbed INUTEC SP1 layer on hydrophobized glass spheres and the same adsorbed layer on a hydrophobized glass plate. The results shows strong repulsion between the adsorbed layers when these reached a surface-to-surface distance that is smaller than twice the adsorbed layer. This repulsive interaction was maintained up to 1.5 mol dm-3 Na2SO4.

165 ,

Time scales of spontanoues spreading of drops on soft viscoelastic surfaces ,

Longquan Chen , Technische Universitat Darmstadt , Germany ,

Elmar Bonaccurso , Technische Universitat Darmstadt , Germany ,

Martin E.R. Shanahan , Univ. Bordeaux , France.

It is known that liquid droplets spreading on a soft, viscoelastic surface can be slowed down considerably by the formation of a wetting ridge, or protrusion of the substrate near the triple phase contact line (TPCL) due to capillary forces. Viscoelastic dissipation in the solid surface can prevail over viscous dissipation in the liquid and dominate the spreading process. In this contribution we show that a short, rapid spreading stage does exist after the contact of a drop and a viscoelastic surface. The requisite balance determining speed of motion of the TPCL is initially between capillary forces and inertial effects. As spreading proceeds, inertia lessens while the lower spreading speed allows for viscoelastic effects to emerge. We study the transition between inertial and viscoelastic regime by high-speed video microscopy and explain it by a simple theory.

166 ,

Overview of SAGD Water Treatment Processes ,

David Pernitsky , Suncor Energy , Canada.

This presentation gives an overview of the major oil separation and water treatment processes used in Steam Assisted Gravity Drainage (SAGD) operations in the Athabasca Oilsands. General process configurations for diluent-based and high temperature bitumen/water separation processes, and softening and evaporator-based water treatment operations will be discussed. Waste disposal approaches will also be presented.

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167 ,

Thermodynamics of Microdrop Concentrating Processes ,

Fatemeh Eslami , University of Alberta , Canada ,

Janet Elliott , University of Alberta , Canada.

In microfluidic systems, microdrops may be used to manipulate very small amounts of solutes such as ultra-small sub-cellular materials. The microdrops act like a reaction vessel

1 providing appropriate means

for solutes to be concentrated and controlled.

It has been proposed2 to use a hygroscopic oil phase to remove water from an aqueous microdroplet

containing solutes, thereby concentrating them. In this project, by means of thermodynamic calculations, we provide designing factors for concentrating solutes in micro droplets by this process.

Here, we have studied two kinds of solutes: glycerol as an unlimited solubility solute, and sodium chloride as a limited solubility solute. We investigated the equilibrium system properties including final concentration and final size for microdroplets which contain these solutes and compare their behaviour with each other and with experiments where available. It is found that the solubility limit characteristic of the solutes affects the equilibrium of the process considerably. This research was funded by the Natural Sciences and Engineering Research Council (NSERC) of Canada. J. A. W. Elliott holds a Canada Research Chair in Thermodynamics.

References (1) Chiu, D. T. Micro- and nano-scale chemical analysis of individual sub-cellular compartments. TrAC - Trends in Analytical Chemistry 2003, 22, 528-536. (2) He, M.; Sun, C.; Chiu, D. T. Concentrating Solutes and Nanoparticles within Individual Aqueous

Microdroplets. Anal. Chem. 2004, 76, 1222-1227.

168 ,

Probing Structure-Nanoaggregation Relations of Polyaromatic Surfactants in the Bulk Phase and at the Oil/Water Interface: A Molecular Dynamics Simulation ,

Robel B. Teklebrhan , Department of Chemical & Materials Engineering, University of Alberta , Canada ,

Lingling Ge , Department of Chemical & Materials Engineering, University of Alberta , Canada ,

Subir Bhattacharjee , Department of Mechanical Engineering, University of Alberta , Canada ,

Zhenghe Xu , Department of Chemical & Materials Engineering, University of Alberta , Canada ,

Johan Sjoblom , Department of Chemical Engineering, Ugelstad Laboratory , Norway.

It is well-known that polyaromatic associations in crude oil leads to precipitation and deposition of the condensed polyaromatic fraction of the crude oil during transportation and production, which results in blocking of reservoir rocks and transport pipes. Furthermore, the accumulation of these interfacially active polyaromatic molecules adsorbed from the bulk oil phase through the various intermolecular interactions promote the formation of cross-linked viscoelastic interfacial films, which stabilize water‐in‐oil emulsions. In this study, five well-defined polyaromatic surfactants (PA) based on perylene bisimide moieties were used as building blocks to probe structure-nanoaggregation relationship in the bulk and at the oil/water interface through Molecular dynamics (MD) simulations and light scattering experiments. The results indicate that variation in the structure of side chains and polarity of functional groups leads to significant variations in molecular association, dynamics of molecular nanoaggregation and structure of nanoaggregates at the bulk phase. The aromatic solvent is shown to

hinder molecular association by weakening - stacking, demonstrating the control of molecular aggregation by tuning solvent properties. Depending on the nature of side chains attached, the stacking

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distributions and aggregate sizes were obtained. The radial distribution function and density profiles of the system also show that PA surfactants tend to adsorb at the oil/water interface much more in heptane than in toluene. Charged molecules show a high tendency to adsorb at the oil/water interface through the deprotonated functional group. These deprotonated PA surfactants also slightly lower the interfacial tension of the o/w interface in both heptane and toluene.

169 ,

AC Electric Actuation of Hydrogels Employing Dielectric Coated Electrodes

Joseph Ryan Saunders, Department of Mechanical Engineering, University of Alberta, Canada,

Walied Moussa, Department of Mechanical Engineering, University of Alberta, Canada.

Hydrogels are a type of polymer that responds to environmental stimuli such as; pH gradients, temperature, electric fields, and light. Their stimulation creates an expansion and contraction which has been previously employed in microfluidic valves, pumps, and mixers. Traditionally focus has been on pH and temperature stimulation; however, these mechanisms have long response times and research is expanding into electrical stimulation. Current electrical stimulation research has been limited to low voltage regimes or has been hampered by electrolysis of electrolyte and electrochemical reactions. In this work, a thin film dielectric barrier has been introduced between the hydrogel actuator and stimulating coplanar electrodes. This dielectric barrier prevents any electrolyte electrolysis and electrode corrosion, but also negates the possibility of DC actuation due to electrostatic shield caused by mobile ions in the surrounding electrolyte. Therefore, AC electrical signals must be implemented to overcome electrostatic shielding and allow for electrical hydrogel stimulation. This work presents an analytical model based on electric double layer theories to obtain operational zones for AC frequency-dependent actuation of anionic hydrogels. This critical AC actuation frequency is a function of the dielectric thin film thickness and electrolyte concentration, and is examined for a two and three order of magnitude range, respectively. In addition, this work examines the channel height and electrode spacing’s effect on the effective electrode width and the dielectric film thickness’s effect on the effective electric potential applied across the media/hydrogel. Also, it is shown that for the range of electric potentials and dielectric film thicknesses examined breakdown of the dielectric would not occur. To verify the proposed analytical model, experiments were undertaken examining hydrogel electrical actuation for a specific set of conditions generated by the model. For the experimental examination, the co-planar electrodes had 2 mm spacing; channel height (hydrogel height) was 250 microns; hydrogel diameter was 1 mm; electrolyte concentration was 1 mM KOH; and the dielectric film thickness was 1 micron. These system parameters translate into a theoretical critical frequency of 70 kHz, with minimal loss of electric potential across the dielectric layer. In addition, the unique microchip fabrication will be overviewed which incorporates co-planar electrodes, Parylene-N thin film deposition, in-situ hydrogel lithography, and the hydrogel equilibrium states before electrical actuation. Fabrication challenges associated with the dielectric thin film will be briefly addressed. Lastly, experimental results for critical frequency are compared against the theoretical predictions, and the resultant deformation and response time of the hydrogel is shown. The hydrogel’s were then cyclically actuated above the critical frequency utilizing a pulse width modulation technique to show a swelling and deswelling cycle. This work demonstrates the cyclical electrical actuation of hydrogels employing dielectric coated electrodes utilizing AC electrical signals and pulse width modulation. Future work will examine the effect of increased applied electric potential and electrolyte concentration on actuation response time and deformation for applications in microfluidic valving or pumping systems.

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170 ,

Interfacial characteristics and role of a biodegradable ethylcellulose in demulsification of water in heavy oil emulsions

Zhenghe Xu, Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada, T6G 2V4,

Jun Hou, Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada, T6G 2V4,

Xianhua Feng, Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada, T6G 2V4,

Jacob Masliyah, Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada, T6G 2V4.

Interfacial properties of an environmentally friendly and commercially available polymer, ethylcellulose (EC) in the absence and presence of natural surface active components of heavy oil was studied by measuring interfacial tension and Langmuir isotherm of EC at toluene- or naphtha-water interface. EC addition was found to significantly reduce toluene-water interfacial tension, while the pressure−area isotherms of Langmuir interfacial films indicated displacement of natural surface active components by EC from the interface. Micropipette measurement indicated flocculation and coalescence of stable water-in-diluted bitumen emulsion droplets at low and high concentrations of EC in naphtha. From imaging of Langmuir-Blodgett interfacial film, EC was found to destabilize water-in-diluted bitumen emulsions by displacement of the original stable interfacial films, creating EC domains which allow for coalescence of water droplets upon contact. The effective demulsification of water-in-diluted bitumen emulsions was confirmed by standard laboratory bottle tests.

171 ,

Surfactants for size Selective Synthesis of Metal Nanoparticles (NPs)

Tarasankar Pal, Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India

Amongst innumerable applications of surfactants, face selective capping of metal nanoparticles has been demonstrated recently in black and white. As a result of which size selective nanoparticle (NP) synthesis is possible. The best possible synthetic strategy to obtain spherical gold-NPs has so far been discussed is citrate reduction reaction.

1 Because of the nobility of gold, relating to standard reduction potential of Au

(III)/Au (0) [1.50V], it becomes possible to exploit very many reductants.2 It is known that the general

sequence of surface energy for different crystallographic Au fcc planes follows the trend (111) < (100) < (110). Experimentally a different order [(111) < (110) < (100)] has often been observed in the solution phase.

3 Thus respective surface energies of Au crystals can be significantly altered by the adsorption of

capping agents and by performing the reaction within micelles. The research began with gold nanorod (NR) synthesis via seed mediated method.

4 However, in cetyltrimethylammonium bromide (CTAB)

solution in presence of AgNO3, Au NR has been produced.5 Careful selection of capping agents can

facilitate morphology change in nanoparticle synthesis and eventual purification to make the particles useful for very specific purpose.

6 Au is a ‘soft’ metal and also a non-toxic metal. Interestingly Au NPs bear

a rich Plasmon band (λmax~520 nm) in the visible. Thus Au NPs of different size and shape find wide number of applications in different fields of applied research including catalysis.

7 Similarly other metals

are being produced using face selective capping agents. There surfactants play a major role for selective capping producing particles of various sizes and shapes leaving aside stabilization of metal NPs in surfactants.

8

Reference:

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1. Frens, G. Nature (London), Phys. Sci. 1973, 241, 20. 2. Pal, T.; Ganguly, A.; Maity, D. S. Analyst 1986, 111, 691. 3. Wang, Z. L.; Mohamed, M. B.; Link, S.; El-Sayed, M. A. Surface Sc. 1999, 440, L809. 4. Jana, N.R., Gearheart, L., Murphy, C. J. J. Phys. Chem. B 2001, 105, 4065. 5. Jana, N. R. Small 2005, 1, 875. 6. Sun, Y.; Gates, B.; Mayers, B.; Xia, Y. Nano Lett. 2002, 2, 165. 7. Murphy, C. J.; Gole, A. M.; Stone, J. W.; Sisco, P. N.; Alkilany, A. M.; Goldsmith, E. C.; Baxter, S. C.

Acc. Chem. Res. 2008, 41, 1721. 8. Pradhan, M.; Sarkar, S.; Sinha, A. K.; Basu, M.; Pal, T. J. Phys. Chem. C 2010, 114, 16129.

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Immobilized Surfactant on Solids for environmental remediation

Anjali Pal, Department of Civil Engineering, Indian Institute of Technology, Kharagpur 721302, India.

Surfactants have many fold application and it has enormous ability to cover solid surfaces. Sometimes, the interaction of surfactant with solid surfaces may be electrostatic in nature. Then surfactant covered solid surfaces are termed as ‘modified solids’. The solid surface in association with surfactant exhibits widely different stability under varied solution condition viz., pH, temperature, electrolyte concentration etc. Again solution pH is capable of offering different surface charge to the solid surfaces. Sometimes the surface charge of the solid may be positive, negative or zero i.e., neural. There a new term, ‘zero point charge’ (zpc) for a chosen solid arises for neutral pH. The positive or negative charge of the solids in question carries enough stability to the surfactant modified solid. Under such a situation the modified solid surfaces become a host that invites guest molecules. The guest molecules may be different water pollutants, organic molecules and even another surfactant. Thus the host-guest interaction interplays in the environmental remediation. The modified surfaces become a well defined host for removal of different dye molecules. It has been shown that under neutral pH (7.0) condition water insoluble solid alumina binds to anionic surfactant like sodium dodecyl sulfate, SDS. Thus SDS modified alumina by the dint of inherent negative charge of SDS invites cationic dyes like crystal violet (CV), malachite green (MG) etc. In turn dye molecules are solubilized onto the modified alumina surfaces through a process called ‘adsolubilization’. This has shown a viable technique for environmental process technology.

Interestingly the surfactant modified alumina has been used for dye speciation (concentration and removal). Thus dye finds a newer route for further use after desorption from the surfactant modified alumina. There comes waste management and a new upcoming field ‘zero waste’ generation. Thermodynamic parameters have been evaluated and ‘adsolubilization’ has gained a firm ground.

References 1) A. Adak & Anjali Pal, “Removal of Phenol from Aquatic Environment by SDS-modified Alumina: Batch and Fixed Bed Studies”, Sep. Purif. Technol. 2006, 50(2), 256-262 2) A. Adak, Anjali Pal & M. Bandyopadhyay, Removal of Phenol from Water Environment by Surfactant-modified Alumina Through Adsolubilization, Coll. Surf. A. 2006, 277, 63-68. 3) A. Adak, M. Bandyopadhyay & Anjali Pal, Fixed Bed Column Study for the Removal of Crystal Violet (C. I. Basic Violet 3) Dye from Aquatic Environment by Surfactant-Modified Alumina, Dyes and Pigments, 2006, 69, 245-251. 4) A. Adak, M. Bandyopadhyay & Anjali Pal, “Removal of Crystal Violet Dye from Wastewater by Surfactant-Modified Alumina”, Sep. Purif. Technol., 2005, 44, 139-144.

140 SIS2012

173 ,

Polymers in Action: Nontraditional Waste Water Treatment Methods in Oilfield Applications Amir Mahmoudkhani, Kemira R&D Centre, Atlanta, GA, USA.

Many phases of the extraction/production process use large volumes of clean fresh water and produce significant amounts of contaminated water as a by-product. Water produced during oil and gas extraction constitutes the industry’s most important waste stream on the basis of volume. Typically, costly operations are needed to bring in clean water for use and transport the contaminated water to an off-site or in-site facility for treatment and disposal. The oil and gas industry produces more than 250 million barrels of water per day. Government restrictions are put on the quality of water-discharge, but the self-imposed corporate guidelines provided by the oil-companies are often more stringent. As a result, a water treatment process running smoothly with a fitting structure adaptable to the present infrastructure is essential in reaching this goal. When selecting produced water treatment technologies, one should focus on reducing the major contributors to the total environmental impact. Among contaminants present in produced water, soluble and semi-soluble organics and toxic inorganic species are often found to be difficult and costly to treat. Polymer coagulation and flocculation methods have been extensively used in other industries for the removal of dissolved and suspended organic and inorganic species from water and wastewater streams. However, conventional approaches were unsuccessful to provide adequate performance in some challenging oilfield applications. We are presenting some non-traditional methods where polymers can be used for treatment of samples from offshore platforms, refineries and process water. Results from our studies indicate the viability of nontraditional polymer treatment for water management in production facilities with minimum or no need for capital equipment.

174 ,

Advanced Oxidation Processes in Water Treatment Kaj Jansson, Kemira Oyj, Helsinki, Finland.

Since 1987 Advanced Oxidation Technology (AOT) and Advanced Oxidation Processes (AOP) has been tried to treat several kinds of waters. The heart of this technology is to use OH° - radicals to split/destroy difficult molecules, typically phenolic molecules, to be treated with common technologies as coagulation or biological treatments. Because of it reactiveness, the OH° - radicals has to be produced in the water where it supposed to do the work. During the years there has been variety of methods on how to produce it on site, as well as comparison with different other oxidative chemistries. In early days people put high hopes in removing basically all organics from waste waters with this technologies, but found it both very expensive and difficult to achieve the target. Today’s focus is on using it mainly as tertiary treatment step, in which the most recalcitrant organic and inorganic contaminants can be eliminated by more economical way. In Kemira we have been looking and using these technologies since those times, trying to learn the chemistries and what can be achieved in waste water treatment with these technologies in different industry waters. Everything from raw- , process- and waste waters has been tried with these technologies. This presentation includes background on AOP technologies and results achieved from laboratory-, pilot- and full-scale trials.

175 ,

Chemical additives: Future opportunities for bitumen exploitation

Uriel Guerrero, Suncor Energy, Calgary, Alberta, Canada.

Almost 30 years have past since the beginning of the development of steam assisted gravity drainage (SAGD) for bitumen extraction. However no major developments have occurred since SAGD became

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commercial. The injection of chemical additives for oil extraction is a technique that has been in the oil industry for almost a century, however it's success in steam based environments is limited. The purpose of this talk is to open a window into the great number of opportunities that the chemical injection can found in the steam base bitumen extraction processes. The challenges and questions that remain unanswered will be outlined with the objective of steering research towards those areas and closing the gap between concept and commercial reality.

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List of Authors

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Author Name Institution Country

A. Khanal Carnegie Mellon University United States

A. S SARPAL Indian Oil Corporation, R&D, Centre, Faridabad India

Aamna Balouch National Centre of Excellence in Analytical Chemistry, University of Sindh

Pakistan

Abeer Al-Bawab Hamdi Mango Research Center, University of Jordan Jordan

Afonso Dantas Neto Federal University of Rio Grande do Norte Brazil

Aijaz Ahmad Dar Department of chemistry, University of Kashmir India

Ajay Ranka Zydex industries, Vadodara, Gujarat India

Ala'a Eftaiha University of Saskatchewan Canada

Alexander V. Makiesvki Sinterface Technology - Berlin Germany

Alexandra Maklakova Murmansk State Technical University Russian Federation

Ali Faghihnejad University Of Alberta Canada

Ali Reza Tehrani Bagha Department of Chemical and Biological Engineering, Chalmers University of Technology

Sweden

Alida Veliz Intevep - PDVSA Venezuela

Alidad Amirfazli University of Alberta - Mechanical Engineering Canada

Aliyar Javadi Max Planck Institute of Colloids and Interfaces Germany

Alma Mendoza Universidad Complutense Spain

Altynay Sharipova Kazakh National Technical University after K.I.Satpaev Kazakhstan

Amanda Schober Firmenich Inc. United States

Amelia Torcello-Gomez University of Granada Spain

Americo Boza Troncoso University of Toronto Canada

Amir Mahmoudkhani Atlanta R&D Center, Kemira, Atlanta, GA United States

Ana Cristina Silva Federal University of Bahia Brazil

Ana Forgiarini Universidad de Los Andes Venezuela

Ana Garcia University of Carabobo Venezuela

Anand Subramaniam Firmenich Inc. United States

Andrea Kargerova Faculty of Chemistry, BRNO UNIVERSITY OF TECHNOLOGY Czech Republic

Andrew J. B. Milne University of Alberta - Mechanical Engineering Canada

Andrew Woodside ConocoPhillips, Bartlesville, OK United States

144 SIS2012

Anjali Pal Department of Civil Engineering, Indian Institute of Technology, Kharagpur 721302

India

Anoop Sonker Indian Institute of Technology Madras India

Antonin Marchand ESPCI Paris France

Aparna Raju Sagi Rice University United States

Ardak Sapieva Astana Medicinal University Kazakhstan

Artur Valente Dept. Chemistry, University of Coimbra Portugal

Asami Aoki LION Corporation Japan

Asdrubal Canache Universidad de Los Andes Venezuela

Atsushi Takahara IMCE、Kyushu University and JST ERATO Takahara Soft Interfaces Project

Japan

Axel Böttcher BASF Personal Care and Nutrition GmbH Germany

Ayat Bozeya Hamdi Mango Research Center, University of Jordan Jordan

Azymbek Kokanbayev Al-Faraby Kazakh National University Kazakhstan

Ben Fieldhouse Environment Canada Canada

Benoît Liberelle École Polytechnique de Montréal Canada

Bharat Gupta DDU, Chem Engg Dept, Nadiad, Gujarat India

Bidyut Paul Indian Statistical Institute, Kolkata India

Bikky Kumar University of Calgary Canada

Birendra Kumar School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur Chhattisgarh India 492010

India

Björn Klotz BASF Personal Care and Nutrition GmbH Germany

Björn Lindman University of Coimbra Portugal

Boris A. Noskov St.Petersburg State University - Dept. Colloid Chemistry Russian Federation

Boris Stoeber UBC Canada

Brendan Miller UW-Milwaukee United States

Brian Grady Institute for Applied Surfactant Research and School of Chemical, Biological & Materials Engineering, University of Oklahoma, Norman, OK

United States

Brigitte Papahadjopoulos-Sternberg

NanoAnalytical Laboratory United States

Bruno Andreotti ESPCI Paris France

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C.G. van Ginkel Akzo Nobel Chemicals Research, 6800 SB Arnhem, The Netherlands

Netherlands

Carlo Carraro University of California at Berkeley United States

Carmen Boeriu Wageningen University and Research Centre Netherlands

Carmen L. Moraila-Martínez University of Granada Spain

Catherine Whitby Ian Wark Research Institute, University of South Australia Australia

Catia Rossi Federal University of Rio Grande do Norte Brazil

Chan Woo Park KAIST Korea, Republic Of

Chandra W. Angle CanmetENERGY, Natural Resources Canada Canada

Charles A. Lucy Department of Chemistry, University of Alberta Canada

Charles Thomas Tiorco United States

Chi Hong Sum School of Pharmacy, University of Waterloo Canada

Christelle Tisserand Formulaction France

Ciro Semprebon MPI-DS Germany

Clara morita Tokyo University of Science Japan

Clarence Miller Rice University United States

D. Peter Tieleman University of Calgary

Dalia Mahmoud Applied Surfactant Laboratory, Petrochemicals Department, Egyptian Petroleum Research Institute

Egypt

Daniel Crespy Max Planck Institute for Polymer Research Germany

Daniel Herde MPI-DS Germany

Daniela Rodríguez Intevep - PDVSA Venezuela

David Fairhurst Nottingham Trent University United Kingdom

David Pernitsky Suncor Energy Canada

Dawid Podolak Lublin University of Technology Poland

Deepti Tikariha School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur Chhattisgarh India 492010

India

Deynis Quevedo VENOCO Venezuela

Diat Olivier Institute for Separative Chemistry of Marcoule France

Dieter Vollhardt Max Planck Institute of Colloids and Interfaces Germany

Dinesh O. Shah Shah-Schulman Center for Surface Science and Nanotechnology, Dharmsinh Desai University, Nadiad, Gujarat

India

146 SIS2012

Dominik Kosior Institute of Catalysis and Surface Chemistry PAS Poland

Dominique Langevin Université Paris Sud 11 France

dong-woog Lee University of California Santa Barbara United States

Doris Vollmer Max Planck Institut for Polymer Research Germany

E. Peterson Carnegie Mellon University United States

Edgar Acosta University of Toronto Canada

Eduardo Guzmán CNR - Istituto per l'Energetica e le Interfasi, Genova Italy

Eduardo Marques University of Porto Portugal

Eduardo Mendez-Villuendas University of Calgary

Edward Mączka Lublin University of Technology Poland

Edward Martínez PDVSA Intevep Venezuela

Elaine Baydak University of Calgary Canada

Elmar Bonaccurso Technische Universität Darmstadt Germany

Erik van der Linden Wageningen University Netherlands

Eshu Middha Indian Institute of Technology Madras India

Eugene Aksenenko Institute of Colloid Chemistry and Chemistry of Water Ukraine

Eva Ravera CNR - Istituto per l'Energetica e le Interfasi, Genova Italy

Eva Santini CNR-Istituto per l'Energetica e le Interfasi, Genova Italy

Ewerton Teixeira Federal University of Rio Grande do Norte Brazil

F. Gao Carnegie Mellon University United States

Fan Yang Dept. of Chemical and Materials Eng., University of Alberta, Edmonton

Canada

Fatemeh Eslami University of Alberta Canada

Fernando Martinez Pedrero Universidad Complutense Spain

Filipe Antunes University of Coimbra Portugal

Francesca Ravera CNR-Istituto per l'Energetica e le Interfasi, Genova Italy

Francisco Monroy Universidad Complutense de Madrid Spain

Francisco Ortega Universidad Complutense Spain

Francisco Sampaio Neto Federal University of Bahia Brazil

Franklin Quintero PDVSA Intevep Venezuela

Gabriel Espinosa University Morelia Mexico

Gabriela Camacaro University of Carabobo Venezuela

Gaelle Martin-Gassin Institute for Separative Chemistry of Marcoule France

Gaugin Gyanendra Singh Indian Institute of Technology Madras India

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George Hirasaki Rice University United States

Georgi Gochev Max Planck Institute of Colloids and Interfaces Germany

Gerd Persson Mid Sweden University Sweden

Gerrard Marangoni St. Francis Xavier University Canada

Girma Biresaw Bio-Oils Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service

United States

Glenda Noboa Universidad de Los Andes Venezuela

Grigor Bantchev Bio-Oils Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service

United States

Guangzhe Yu Institute for Applied Surfactant Research and School of Chemical, Biological & Materials Engineering, University of Oklahoma, Norman, OK

United States

Gudrun Petzold Leibniz - Institut für Polymerforschung Dresden e.V. Germany

Guillermo Smart Formulaction Inc United States

Gulnur Alimbekova Kazakh National Technical University after K.I.Satpaev Kazakhstan

Gulzhan Seit Al-Faraby Kazakh National University Kazakhstan

Guzman Eduardo CNR - Istituto per l'Energetica e le Interfasi, Genova Italy

Håkan Edlund Mid Sweden University Sweden

Hans Oskarsson Department of Chemical and Biological Engineering, Chalmers University of Technology

Sweden

Hans-Jörg Mögel TU Bergakademie Freiberg Inst. Phys. Chem. Germany

Hans-Jürgen Butt Max Planck Institut for Polymer Research Germany

Hans-Martin Haake BASF Personal Care and Nutrition GmbH Germany

Harsha Paroor Max Planck Institut for Polymer Research Germany

Harvey Yarranton University of Calgary Canada

Hee Jin Seo Kangwon National University Korea, Republic Of

Hee-Man Yang KAIST Korea, Republic Of

Henk Schols Wageningen University Netherlands

Hezekiah Agogo Universidad Complutense Spain

Hida Hasinovic Ashland, Inc. United States

Hiroshi Endo Tokyo University of Science Japan

Hongbo Zeng University Of Alberta Canada

148 SIS2012

Horacimone Lopes Federal University of Bahia Brazil

HUGO PARRA C.A. Venezolana de Pinturas. Valencia, Venezuela Venezuela

Hyun Ju Cha Kangwon National University Korea, Republic Of

Ian Pleasant Institute for Applied Surfactant Research and School of Chemical, Biological & Materials Engineering, University of Oklahoma, Norman, OK

United States

Ibrahima Ba Université de Montréal Canada

Ida Högberg Mid Sweden University Sweden

Jacco Snoeijer University of Twente Netherlands

Jack Ackrell NanoAnalytical Laboratory United States

jacob israelachvili University of California Santa Barbara United States

Jacob Masliyah Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta,

Canada

James Kwan Colorado University - Boulder United States

Jan Czarnecki Dept. of Chemical and Materials Eng., University of Alberta, Edmonton

Canada

Jan Zawala Natural Resources Canada, Devon Canada

Jan Zawala Jerzy Haber Institute of Catalysis and Surface Chemistry PAS

Poland

Jan-Erik Löfroth Department of Chemical and Biological Engineering, Chalmers University of Technology

Sweden

Janet A. W. Elliott University of Alberta - Chemical and Materials Engineering Canada

Janet Elliott University of Alberta Canada

Javed Akbar University of Waterloo Canada

Jean-Louis Salager Universidad de Los Andes Venezuela

Jeffrey Harwell Institute for Applied Surfactant Research and School of Chemical, Biological & Materials Engineering, University of Oklahoma, Norman, OK

United States

Jens Hillerich Bernd Schwegmann GmbH & Co. KG Germany

Jeong Woo Lee Korea Advanced Institute of Science and Technology (KAIST)

Korea, Republic Of

Jin-Chul Kim Kangwon National University Korea, Republic Of

jing yu University of California Santa Barbara United States

SIS2012 149

Jingcheng Hao Key Laboratory of Colloid and Interface Chemistry, Shandong University

China

Joachim Koetz University of Potsdam Germany

Joakim J. Kärnbratt Department of Chemical and Biological Engineering, Chalmers University of Technology

Sweden

Johan Sjöblom Ugelstad Laboratory, Department of Chemical Engineering, Norwegian University of Sciences and Technology (NTNU), Trondheim

Norway

Johnny Bullon Universidad de Los Andes Venezuela

Jonathan Kwan ConocoPhillips United States

Jong-Duk Kim KAIST Korea, Republic Of

Jong-Duk Kim Korea Advanced Institute of Science and Technology (KAIST)

Korea, Republic Of

Jörg Bohrisch Fraunhofer Institut für Angewandte Polymerforschung Germany

José Fabricio Melo Federal University of Rio Grande do Norte Brazil

José González PDVSA Intevep Venezuela

Joseph Ryan Saunders Department of Mechanical Engineering, University of Alberta

Canada

Juan Antonio Holgado-Terriza

University of Granada Spain

Juan C. Pereira Universidad de Carabobo Venezuela

Juan López Universidad de Los Andes Venezuela

JUAN PEREIRA Laboratorio de Petróleo, Hidrocarburos y Derivados, Departamento de Química, Facultad Experimental de Ciencias y Tecnología, Universidad de Carabobo, Valencia, Venezuela

Venezuela

JUAN PINTO C.A. Venezolana de Pinturas. Valencia, Venezuela Venezuela

Juergen Kraegel MPI Colloids and Interfaces Germany

Julia Maldonado-Valderrama


Juliette Cayer-Barrioz LTDS-CNRS UMR5513-Ecole centrale de Lyon France

Jun Hou Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta,

Canada

Jürgen Allgaier FZ Jülich Germany

Jürgen Krägel Max Planck Institute of Colloids and Interfaces Germany

Kabir ud-Din Aligarh Muslim University India

150 SIS2012

Kaipeng Wang University of Alberta Canada

Kaj Jansson KemiraOyj, P.O.Box 330 FIN-00101Helsinki Finland

kallol K Ghosh School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur Chhattisgarh India 492010

India

Kasper Moth-Poulsen Department of Chemical and Biological Engineering, Chalmers University of Technology

Sweden

Kasper Nørgaard Department of Chemical and Biological Engineering, Chalmers University of Technology

Denmark

Kathrin Friedemann Max Planck Institute for Polymer Research Germany

Kaushik Kundu Indian Statistical Institute, Kolkata India

Kazimierz Malysa Jerzy Haber Institute of Catalysis and Surface Chemistry PAS

Poland

Keila Melo Federal University of Rio Grande do Norte Brazil

Kenichi Aburai Tokyo University of Science Japan

Ko Higashitani Kyoto University Japan

Koji Miyake National Institute of Advanced Industrial Science and Technology (AIST)

Japan

Krister Holmberg Department of Chemical and Biological Engineering, Chalmers University of Technology

Sweden

Krister Holmberg Akzo Nobel Chemicals Research, 6800 SB Arnhem, The Netherlands

Sweden

Krister Holmberg Department of Chemical and Biological Engineering, Chalmers University of Technology

Sweden

Kuan-Hung Cho National Taiwan University Taiwan

Kuanyshbek Musabekov Al-Faraby Kazakh National University Kazakhstan

Kuralay Korzhynbayeva Al-Faraby Kazakh National University Kazakhstan

Kyle Baldwin Nottingham Trent University United Kingdom

Kyle Karinshak Institute for Applied Surfactant Research and School of Chemical, Biological & Materials Engineering, University of Oklahoma, Norman, OK

United States

Kyriakos Alexandros Eslahian

BAM Federal Institute for Materials Research and Testing Germany

Larry Unsworth University of Alberta Canada

Lars Nordstierna Department of Chemical and Biological Engineering, Chalmers University of Technology

Sweden

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Lars Schönberger Leibniz - Institut für Polymerforschung Dresden e.V. Germany

Laura Arriaga University Harvard United States

Laura Bonales Universidad Complutense Spain

Laura Márquez Universidad de Los Andes Venezuela

Laurence Romsted Rutgers, The State University of New Jersey United States

Lee R. White University of South Australia Australia

Lei Pei Department of Chemistry, University of Alberta Canada

Lei Wang University of Alberta Canada

Lena Mammen Max Planck Institute for Polymer Research Germany

Leonard Sagis Wageningen University Netherlands

Li-Jen Chen National Taiwan University Taiwan

Libero Liggieri CNR - Istituto per l'Energetica e le Interfasi, Genova Italy

Liliana Fernández Universidad de Los Andes Venezuela

Ling Zhang University of Alberta Canada

Lingling Ge Department of Chemical & Materials Engineering, University of Alberta

Canada

Lisa Lotte Ian Wark Research Institute, University of South Australia Australia

LISBETH GIESURIN C.A. Venezolana de Pinturas. Valencia, Venezuela Venezuela

Longquan Chen Technische Universität Darmstadt Germany

Luis Alves University of Coimbra Portugal

Luis Marcano PDVSA Intevep Venezuela

Lyudmila Petrova Murmansk State Technical University Russian Federation

M Kamil AMU Aligarh India

M Suhail AMU Aligarh India

Mabya Fechner University of Potsdam Germany

Magnus Norgren Mid Sweden University Sweden

Magnus Nydén Department of Chemical and Biological Engineering, Chalmers University of Technology

Sweden

Mahmoud F. Bahnasy Department of Chemistry, University of Alberta Canada

Makoto Yuasa Tokyo University of Science Japan

Manish Mishra Shah-Schulman Center for Surface Science and Nanotechnology, Faculty of Technology, Dharmsinh Desai University, College Road, Nadiad – 387 001, Gujarat, India

India

152 SIS2012

Manu Vashishtha Shah-Schulman Center for Surface Science and Nanotechnology, Faculty of Technology, Dharmsinh Desai University, College Road, Nadiad – 387 001, Gujarat, India

India

Manuel Velarde Universidad Complutense Spain

Marcel Krzan Jerzy Haber Institute of Catalysis and Surface Chemistry PAS

Poland

Marceli Sanchez Industrias VENOCO Venezuela

Marcio Machado University of Alberta Canada

Marek Kosmulski Lublin University of Technology Poland

Maria D'Acunzi Max Planck Institute for Polymer Research Germany

Maria Moura Federal University of Rio Grande do Norte Brazil

Mark Borden Colorado University - Boulder United States

Markus Biesalski Laboratory for Macromolecular Chemistry and Paper Chemistry,Department of Chemistry, Petersenstrasse 22, 64287 Darmstadt, TU Darmstadt

Germany

Markus Bussmann Mechanical and Industrial Engineering, University of Toronto

Canada

Martin Brinkmann MPI-DS Germany

Martin E.R. Shanahan Univ. Bordeaux France

Mathias Fleury Formulaction France

Matthew Paige University of Saskatchewan Canada

Maura Puerto Rice University United States

Mehdi Salehi Tiorco United States

Melinda Krebsz Ian Wark Research Institute, University of South Australia Australia

Meriem Jabnoun Schwan-Stabilo Cosmetics Germany

Merv Fingas Spill Science Canada

Michael Maskos Institut für Mikrotechnik Mainz Germany

Michele Ferrari CNR - Istituto per l'Energetica e le Interfasi, Genova Italy

Miguel A. Rodríguez-Valverde


Miguel Angel Cabrerizo-Vilchez


Miki Nakano National Institute of Advanced Industrial Science and Technology (AIST)

Japan

Milad Motamedi Institute for Color Science and Technology, Tehran, Iran Iran

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Miloslav Pekar Faculty of Chemistry, BRNO UNIVERSITY OF TECHNOLOGY Czech Republic

Mirco Wahab TU Bergakademie Freiberg Inst. Phys. Chem. Germany

Mohammad Mahdavian Department of Polymer Engineering, Sahand University of Technology, Tabriz, Iran

Iran

Mohan Nair Kemira R&D Centre United States

Mojtaba Binazadeh University of Alberta Canada

Moldir Kerimkulova Al-Faraby Kazakh National University Kazakhstan

Motoyasu Kobayashi JST ERATO Takahara Soft Interfaces Project Japan

Muhammad Arshad Khosa Quaid-i-Azam University Islamabad Pakistan

Nabel Negm Applied Surfactant Laboratory, Petrochemicals Department, Egyptian Petroleum Research Institute

Egypt

Nafiseh Nafissi School of Pharmacy, University of Waterloo Canada

Nail Abdulin St.Petersburg University Russian Federation

Naser Tavakoli Isfahan Medical University Iran

Natalia Kochurova St.Petersburg University Russian Federation

Nenad Mucic Max Planck Institute of Colloids and Interfaces Germany

Neyla Bekturganova Kazakh National Technical University after K.I.Satpaev Kazakhstan

Nikolay Voronko Murmansk State Technical University Russian Federation

Nina Kovalchuk Institute of Bio-Colloid Chemistry Ukraine

Norio Tobori LION Corporation Japan

Octavio Furlong National University of San Luis Argentina

Olga Borozenko Université de Montréal Canada

Olivier Diat Marcoule Institute for separative Chemistry France

Olle Söderman Physical Chemistry 1, Lund University Sweden

Paolo Sabatino Ghent University Belgium

Patrick Laplante University of Alberta Canada

Paulina Zychowska Jerzy Haber Institute of Catalysis and Surface Chemistry PAS

Poland

Periklis Papadopoulos Max Planck Institut for Polymer Research Germany

Peter Schiller TU Bergakademie Freiberg Inst. Phys. Chem. Germany

Pierre-Marie Gassin Institute for Separative Chemistry of Marcoule France

154 SIS2012

Plamen Tchoukov Dept. of Chemical and Materials Eng., University of Alberta, Edmonton

Canada

Poorya Ferdowsi Mechanical and Industrial Engineering, University of Toronto

Canada

Prakash Mehta Zydex Industries, Vadodara, Gujarat India

Prashant Rakhmaji Waghmare

Micro and Nano-scale Transport Laboratory Department of Mechanical Engineering University of Alberta

Canada

Qi Liu University of Alberta Canada

Qing Gu Rutgers, The State University of New Jersey United States

Qingxia Liu University of Alberta Canada

R. Kalita Carnegie Mellon University United States

R. S. Fougat AUA, Anand, Gujarat India

R. Sharma Carnegie Mellon University United States

R. Tilton Carnegie Mellon University United States

Radomir Slavchev Sofia University, Department of Physical Chemistry, Sofia Bulgaria

Rajdeep G. Singh Department of Chemical and Biological Engineering, Chalmers University of Technology

Sweden

Ramon Rubio Universidad Complutense Spain

Raquel Chulia Jordan Universidad Complutense Spain

Raquelisa Arellano PDVSA Venezuela

Reinhard Miller Max-Planck Institute of Colloids and Interfaces Germany

Renate Beisser FZ Jülich Germany

Renhao Dong Key Laboratory of Colloid and Interface Chemistry, Shandong University

China

Ri Li University of British Columbia Canada

Ricardo Lima Leite Federal University of Semiaride Brazil

Robel B. Teklebrhan Department of Chemical & Materials Engineering, University of Alberta

Canada

Robert Li Shell United States

Roderick Slavcev School of Pharmacy, University of Waterloo Canada

Rosana Rojas Leibniz Institute of Polymer Research Dresden Germany

Roya Maboudian University of California at Berkeley United States

Ryo TSUBOI Tokyo University of Science Japan

S. Garoff Carnegie Mellon University United States

Sabine Genest Leibniz - Institut für Polymerforschung Dresden e.V. Germany

SIS2012 155

Sagdat Tazhibayeva Al-Faraby Kazakh National University Kazakhstan

Sajan Daniel George Institute for Nano- and Microfluidics, Center of Smart Interfaces, Petersenstrasse 32, Darmstadt 64287

Germany

Sakhawat Shah Hazara University Mansehra, Khyber Pakhtunkhwa Pakistan

Salah Tawfik Petrochemicals Department, Egyptian Petroleum Research Institute

Egypt

Samson Ng Syncrude Research Center Canada

Sandra Schütze Leibniz Institute of Polymer Research Dresden Germany

Sasan Mehrabian University of Toronto Canada

Saule Aidarova Kazakh National Technical University after K.I.Satpaev Kazakhstan

saurabh Das University of California Santa Barbara United States

Seiya Watanabe Tokyo University of Science Japan

Seong H. Kim Pennsylvania State University United States

Sergey Semenov Loughborough University United Kingdom

Shawn Wettig School of Pharmacy, University of Waterloo Canada

Shinya Sasaki Tokyo University of Science Japan

Siddhartha Das Micro and Nano-scale Transport Laboratory Department of Mechanical Engineering University of Alberta

Canada

Silvia van Kempen Wageningen University Netherlands

Simona Schwarz Leibniz - Institut für Polymerforschung Dresden e.V. Germany

Soumen Ghosh Jadavpur University India

Steffen Hardt Institute for Nano- and Microfluidics, Center of Smart Interfaces, Petersenstrasse 32, Darmstadt 64287

Germany

Stephan Herminghaus MPI-DS Germany

Stig E. Friberg Ugelstad Laboratory, NTNU Norway

Subir Bhattacharjee Department of Mechanical Engineering, University of Alberta

Canada

Subramanyan Namboodiri Varanakkottu

Institute for Nano- and Microfluidics, Center of Smart Interfaces, Petersenstrasse 32, Darmstadt 64287

Germany

Sujit Bhattacharya Syncrude Research Center Canada

Sung Kyeong Hong Kangwon National University Korea, Republic Of

Susanne Boija Mid Sweden University Sweden

156 SIS2012

Sushanta Kumar Mitra Micro and Nano-scale Transport Laboratory Department of Mechanical Engineering University of Alberta

Canada

Susy Varughese Indian Institute of Technology Madras India

Suzanne Giasson Université de Montréal Canada

Suzanne Kresta University of Alberta Canada

Svetlana Baoukina University of Calgary Canada

Svetlana Derkach Murmansk State Technical University Russian Federation

T. Corcoran University of Pittsburgh United States

T. Przybycien Carnegie Mellon University United States

Tadeusz Dabros CanmetENERGY, Natural Resources Canada, Devon Canada

Tahahiro KOYAMA Tokyo University of Science Japan

Takahiro Sagawa Tokyo University of Science Japan

Takeshi Kawai Tokyo University of Science Japan

Takeshi Kondo Tokyo University of Science Japan

Taku Ogura LION Corporation Japan

Tarasankar Pal Department of Chemistry, Indian Institute of Technology, Kharagpur 721302

India

Tatyana Dyakina Murmansk State Technical University Russian Federation

Tereza Neuma Dantas Federal University of Rio Grande do Norte Brazil

Tharwat Tadros 89 Nash Grove Lane Wokingham, Berkshire RG40 4HE, United Kingdom

Theodorus G.M. van de Ven Department of Chemistry, McGill University, Montreal, QC Canada

Titoo Jain Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100, Copenhagen Ø, Denmark

Denmark

Tobias Baier Institute for Nano- and Microfluidics, Center of Smart Interfaces, Petersenstrasse 32, Darmstadt 64287

Germany

Uriel Guerrero Suncor Energy, Calgary, Alberta Canada

Vahid Bazargan UBC Canada

Valery Normand Firmenich Inc. United States

Vanessa González PDVSA Intevep Venezuela

Vanessa Santanna Federal University of Rio Grande do Norte Brazil

SIS2012 157

Victor Coronel Industrias VENOCO Venezuela

Victor Perez University of Carabobo Venezuela

Victor Starov Loughborough University United Kingdom

Victoria Dutschk University of Twente, Faculty for Engineering Technology, Engineering Fibrous Smart Materials (EFSM) research group, Enschede

Netherlands

Vincent Pradines Laboratoire de Chemie de Coordination France

Walied Moussa Department of Mechanical Engineering, University of Alberta

Canada

Wilfred Tysoe UW-Milwaukee United States

Willie L Hinze Department of Chemistry, Salem Hall, Wake Forest University

United States

Wolfgang von Rybinski University of Duesseldorf Germany

Won-Hee Hong KAIST Korea, Republic Of

xavier banquy University of California Santa Barbara United States

Xavier Banquy University of California Santa Barbara United States

Xianhua Feng Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta,

Canada

Xiomara Gutiérrez PDVSA Intevep Venezuela

Xu Deng Max Planck Institut for Polymer Research Germany

Yanguang Shan University of Shanghai for Science and Technology China

Yefrenck Castro Intevep - PDVSA Venezuela

Yoleida Navarro University of Carabobo Venezuela

Yongfu Wu Kemira R&D Centre United States

Yongliang Zhang Rutgers, The State University of New Jersey United States

Yoshiro Imura Tokyo University of Science Japan

Yu-Hao Yeh National Taiwan University Taiwan

Yujuan Hua CanmetENERGY,Natural Resources Canada Canada

Yuri Santos Federal University of Rio Grande do Norte Brazil

Yuriko KONDO Tokyo University of Science Japan

Zhanar Ospanova Al-Faraby Kazakh National University Kazakhstan

Zhenghe Xu Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta,

Canada

158 SIS2012

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