C E N T E R S O F E X C E L L E N C E Center for the Study of Polymer Systems manias @ psu.edu Tailored Polyolefin/layered Tailored Polyolefin/layered - - silicate silicate Nanocomposites with Novel Functionalities Nanocomposites with Novel Functionalities Nanotechnology at ton quantities? Nanotechnology at ton quantities? Evangelos Manias Evangelos Manias Materials Science & Engineering dept Materials Science & Engineering dept Polymer Nanostructures Lab / CSPS Polymer Nanostructures Lab / CSPS [email protected]http://zeus.plmsc.psu.edu/
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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?
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
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 (!!!)