C E N T E R S O F E X C E L L E N C ECenter for the Study of Polymer Systems

manias @psu.edu

Tailored Polyolefin/layeredTailored Polyolefin/layered--silicate silicate Nanocomposites with Novel Functionalities Nanocomposites with Novel Functionalities

Nanotechnology at ton quantities?Nanotechnology at ton quantities?

Evangelos ManiasEvangelos ManiasMaterials Science & Engineering deptMaterials Science & Engineering dept

Polymer Nanostructures Lab / CSPSPolymer Nanostructures Lab / CSPS

manias@psu.eduhttp://zeus.plmsc.psu.edu/

NanocompositesNanocomposites

A Definition1:

Polymer Nanocomposites The proper incorporation of nanoscale inorganic fillers to polymer matrices, so as to achieve novel (non-bulk) properties and multifunctionality(molecular hybrids or genuine nanocomposites 1 ).

Or (more common approach) design concurrent property improvements across a selected set of properties (nanofilled composites 1 ).

Today’s focus:

Polyolefin/Clay Nanocomposites Thermomechanicalenhancements and antimicrobial functionality

1 E. Manias, Nature Materials 6, 9-11 (2007)

Property Enhancements due to nm FillersProperty Enhancements due to nm Fillers

Concurrent Property Changes (cf. the respective pure polymers):improved novel mechanical propertiesdramatically reduced gas permeabilityincreased thermal stabilityincreased fire resistance(environmentally friendly FR additives)

AND Maintainrecyclability flexibility, optical claritylight weight, processability

Examples of “requests” in applications:non-permeable (to gasses/liquids), but flexible and light-weightstiff, but tough and flexible (even for thin films)synergy with conventional-fillers, high-volume, …, cheap (!!)

(in high(in high--performance performance nanofillednanofilled composites)composites)

Achieved with:extremely low filler content (typ. 1-5 wt%)simultaneous and non-trivial improvement in many propertieston-scale quantities

starting particle: agglomerate

• several μm in size (5-20 μm)

• millions of individual plateletsmorelikely

The Challenge: Achieving MiscibilityThe Challenge: Achieving Miscibility

desired

Courtesy: RA Vaia, AFRL, 2oo4

Thermodynamic ArgumentsThermodynamic Arguments

Designing miscible nanocomposites

introduce favorable excess interactionsi.e. polymer-clay interactions better than

clay-surfactant interactions

( )( ) ( )

fillerinorganic,surfactantpolymer,:,

2with

2

jijiji

ABij

LWj

LWi

LWijAB

ijLWijij

−−++ −−=

−=+=

γγγγγ

γγγγγγ

Vaia & Giannelis, Macromolecules, 30, 7990 (1997)

0<− fillersurffillerpol γγ

Structure of nanocompositesStructure of nanocomposites

For naturally occurring fillers (e.g. montmorillonite clay)there coexist intercalated/exfoliated filler structures

TEM A: intercalated layersB: exfoliated/disordered E. Manias et al, Chem. Mater. 13, 3516 (2001)

2D fillers2D fillers

eg. shown: PP/mmt

Mechanical property changesMechanical property changes

0 2 4 6 8 10600

800

1000

1200neat PP / C18H37 -MMT (conv. filler)neat PP / C18H37 & C8H4F13 -MMT

Mod

ulus

(MP

a)

inorganic concentration φ (wt %)

INSTRON; thin film ASTM protocol

0 2 4 6 8 100

200

400

600

800

1000

neat PP / C18H37-MMT (conv. filler)neat PP / C18H37 & C8H4F13 -MMT

Bre

ak s

trai

n (%

)

inorganic concentration φ (wt %)

0 2 4 6 8 1010

15

20

25

30

35

neat PP / C18H37-MMT (conv. filler)neat PP / C18H37 & C8H4F13 -MMTYi

eld

Stre

ss (M

Pa)

inorganic concentration φ (wt %)

“General” changes:tensile modulus 60% increase (small changes in yield stress)(small changes in break strain)

functionalizedfunctionalized0.5%0.5% PP / organoPP / organo--mmtmmt

E. Manias et al, Chem. Mater. 13, 3516 (2001)

Other Thermomechanical PropertiesOther Thermomechanical Properties

0 2 4 6 8 10

110

120

130

140

150

160

PP/ f-mmt (melt) PP/ f-mmt (extr) PP/ 2C18M (extr)

HD

T (o C

)

φ (wt %)E. Manias et al, Chem. Mater. 13, 3516 (2001)

PP heat deflection temperature

Similar trends for:

apparent Tgscratch resistancesurface moduluscompressive G’…

functionalizedfunctionalized0.5%0.5% PP / organoPP / organo--mmtmmt

Polar groups added as a block to PPPolar groups added as a block to PP

A single end-group(appropriately selected) can drive high miscibility.

Tensile Modulus 60%HDT 30oC

Z-M. Wang, H. Nakajima, E. Manias , and T.C. Chung, Macromolecules 36, 8919 (2003)

500nm

H CH2 CH CH2 CH2 NH3

CH3n

endend--functionalized PP / organofunctionalized PP / organo--mmtmmt

Technology leased toMitsubishi, Japan

Tensile Modulus

(MPa)

Tensile Strength (MPa)

Elongation at break

(%) unfilled

(0% Clay)

306 (±15)

24 (±1)

324 (±11) unfilled-TS*

(0% Clay)

329 (± 5)

24 (±1)

291 (± 5)

3% Clay 587 (± 9) 23 (±1) 325 (±11) 6% Clay 825 (±17) 24 (±1) 396 (± 6)

met

hod

A

9% Clay 1120 (±25) 23 (±1) 295 (±23)

3% Clay 581 (±32) 22 (±1) 316 (±17) 6% Clay 842 (±33) 25 (±1) 400 (± 1)

met

hod

B

9% Clay 1106 (±66) 22 (±1) 294 (±13)

Mechanical property changes (LDPE)Mechanical property changes (LDPE)

Heat Deflection TemperatureHeat Deflection Temperature

HDT (oC)

Neat 64.5

3%-Clay 70.5

met

hod

A

9%-Clay 87.0

Neat 63.0

3%-Clay 68.1

met

hod

B

9%-Clay 84.3

E. Manias, J. Zhang, et al., Macromolecular Rapid Comm., 30, 17-23 (2009)

Origin of thermomechanical behaviorOrigin of thermomechanical behavior

30 40 50 60 70 80 90 100 110

0

50

100

150

200

250

300

LDPE film (control) 3% MMT (B, o.66 gauge) 3% MMT (A, o.66 gauge) 3% MMT (B, o.60 gauge) 3% MMT (A, o.60 gauge) 3% MMT (B, o.50 gauge) 3% MMT (A, o.50 gauge)

6% MMT (B, o.60 gauge) 6% MMT (A, o.60 gauge)

Stor

age

Mod

ulus

(G',

MPa

)

Temperature (0C)

Origin of thermomechanical behaviorOrigin of thermomechanical behavior1 10 100

400

600

800

1000

1200

1400

1600

1800

2000

2200

2400

2600

Sto

rage

Mod

ulus

(MP

a)

1 10 100 1 10 100

1 10 100

40 0C0 0C 20 0C-20 0C

F requency (H z)

1 10 100

50

100

150

200

250

300

350

400

450

500

1 10 100

100 0C80 0C60 0C

1 10 100

DMA vs. freq(torsion mode)

LDPE (black) 6% MMT (red) 3mm flex-bars

Barrier propertiesBarrier properties

0.0

0.2

0.4

0.6

0.8

1.0

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Volume Fraction Silicate

Rel

ativ

e Pe

rmea

bilit

y

Nanocomposite(PCL Nanocomposites)

Conventionally filled systems

AB

Data adopted from Giannelis et al., 1994

Origins:path tortuosity

“General” Trend:(amorphous polymers)PDMS PU PUUPS Elastomers...(few semi-crystalline) PVA polyamides

PermeabilityPermeability--Structure RelationStructure Relation

R. Xu, E. Manias, A.J. Snyder & J. Runt Macromolecules, 34, 337-339 (2001)

0

0.005

0.01

0.015

0.02

0.025

0.03

0 200 400 600 800 1000 1200 1400

Extension (%)

PUU

0.3%

0.8%

2%

3.8%

5.9%vol% silicate

Microtensile die (ASTM D1708-93)

PUU Nanocomposites:PUU Nanocomposites:elastomeric character retainedelastomeric character retained

R. Xu, E. Manias, A.J. Snyder & J. Runt Macromolecules, 34, 337-339 (2001)

Still Highly Rubbery !!Still Highly Rubbery !!

barrier incr. bybarrier incr. by 500%500%modulus incr. modulus incr. 500%500%strength incr.strength incr. 400%400%

‘Tortuous Path’

Macromolecules 2001, 34, 9189

effective α alignment

PermeabilityPermeability--Structure RelationStructure Relation

Strategies to orient nanofillersStrategies to orient nanofillers

Sd = 0.8 @ mg systemsabove 20mg sample aligned

with 1500VAC for 10min @ AFRL

Sd = 0.6 @ kg/h systems

above at 50–150 lb/h two independent blow molding lines*

(2D nanoparticles)(2D nanoparticles)Electric-field AlignmentEpoxy/MMTEpoxy/MMT

Flow-induced AlignmentHDPE/MMTHDPE/MMT

* E. Manias, J. Zhang, MM Jimenez-Gasco, et al. Macrom. Rapid Comm., 30, 17-23 (2009)

100μm

Poly(ethylene oxide)Poly(ethylene oxide) PolypropylenePolypropylene syndiosyndio--PolystyrenePolystyrene

PEO/3 wt% mmtPEO/3 wt% mmt PP/3 wt% mmtPP/3 wt% mmt sPSsPS/3 wt% mmt/3 wt% mmt

Nanofillers and polymer crystal morphologyNanofillers and polymer crystal morphologynegative contributions to barrier performance

Antimicrobial ActivityAntimicrobial Activity

Our best performing* nanocomposites, which canbe/are used for flexible packaging, are based on commercial organo-nanofillers and are not antimicrobial

How can we design a nanofiller that affords antimicrobial activity?

Employ surfactants that are promoting dispersion andhave antimicrobial activity !

(in collaboration with Plant Pathology/PSU)

* High-barrier flexible films, Peelable heat-sealants, etcE. Manias, J. Zhang, MM Jimenez-Gasco, et al. Macrom. Rapid Comm., 30, 17-23 (2009)

J. Zhang, E. Manias, C.A. Wilkie, J. Nanoscience and Nanotechnology, 8, 1597 (2008)

Antimicrobial ActivityAntimicrobial Activity(in collaboration with Plant Pathology/PSU)

Polymer/Organo-Filler ActivityActivity retained even when organofillers are

encapsulated in polymer at very low loadings (3% and 6%)

Ponusa Songptiya, M.M. Jimenez–Gasco, E. Manias

Beyond Dispersion Control of Hierarchy of Structurese.g. alignment, house of cards, control at the μm scale, preferential dispersion in one phase or at the interphase

what can be done tomorrow…

PET

PC

Future Outlook: A Personal Perspective Future Outlook: A Personal Perspective

Design and Incorporate Multiple Desired FunctionalitiesAdded beyond barrier + stiffness, cf. antifouling, biodegradable, (di)electrical or radiation, heat-sealing, independently manipulate and tailor specific properties…

Design and Incorporate an Adaptive CharacterIncorporate responses to environmental or chemical changes (not just sensors, but ‘smart’ stimuli-responses)…

Bioinspired Nanostructured Polymers and CompositesHere the opportunities are almost limitless… Look at nature’s examples of structural materials, skins, structures with specific processes, and imagine if we could make synthetic equivalents of such systems/structures…

what can be in the near future…

what can be in the not-so-near future…

Future Outlook: A Personal Perspective Future Outlook: A Personal Perspective

Concluding RemarksConcluding Remarks

Nanotechnology is not nanobots or Star-Trek gadgets !!It can be a polymer nanocomposite that you may already use (e.g. medical/food packaging, automotive, construction,…).

Polymer/inorganic nanocomposites can afford high-impact real-life applications:(1) by affording substantial improvements in performance, overcome property trade-offs of conventional composites (cf.nanofilled polymers new materials, disruptive technologies).(2) by affording new and novel functionalities (cf. genuine nanocomposites transformative research, radically new materials & applications)

Polymer/Inorganic nanocomposites are a viable technology for many “new” materials for near-future structural applications.However, they are not the solution to all problems (!!!)

Collaborators:Collaborators:E. Giannelis (Cornell)

T.C. Chung (PSU)J. Runt (PSU)R. Krishnamoorti (UH)R. Vaia (AFRL)C. Wilkie (Marquette)M. Jimenez-Gasco (PSU)D. Macdonald (PSU)J. Genzer (NCSU) J. Floros (PSU)C. Randall (PSU)

Fuel-Cells:Zijie Lu Hungoo ChoA. Karatrantos Y. Chang

Grad. students:Grad. students:... Jie ChenKen StrawheckerZhiming WangVikram KuppaSung Woo WeeAlexei KisselevMatt HeideckerGreg HogsheadTheresa FoleyPonusa SongptiyaNgoh ManokruangRomesh Patel Financial Support:Financial Support:NIST NSF PDA DoE ONR AFOSR

Air Products UTC/IFC BAYER MATSCCoca-Cola Asahi-Kasei Arrow-BioMedSumitomo Chem PPG Samsung Kraft

Postdocs:Postdocs:Lixin Wu Yang JiangHiroyoshi NakajimaM. RackaitisS. ChowdhuryJin-Huh YoungGeorge PolizosJinguo ZhangK.S. Andrikopoulos

AcknowledgementsAcknowledgementsall cited papers (full-text) here:

http://zeus.plmsc.psu.edu/want a copy of the presentation?

manias@psu.eduManias groupManias group

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