Effects of Confinement on Polymer Structure and Dynamics: The Case of Polymer Nanocomposites

 

 1 Institute of Electronic Structure and Laser / Foundation for Research and Technology-Hellas, Heraklion Crete, Greece

2 Department of Chemistry, University of Crete, Heraklion Crete, Greece

 

Abstract

The behavior of polymers restricted in space or close to surfaces/interfaces can be very different from that in the bulk. In this work, we investigate the morphology and thermal properties of hydrophilic polymers in nanohybrids containing either layered silicates or silica nanoparticles. Mixing polymers with layered silicates can lead to intercalated hybrids when the interactions between the constituents are appropriate; these can serve as model systems for the investigation of the static and dynamic properties of macromolecules in nano-confinement.  On the other hand, using silica particles of largely different sizes is an attempt to bridge the case of polymers confined within the galleries of layered silicates with that of polymer / single nanoparticle nanocomposites. Confinement is shown to modify the polymer structure, e.g., its crystallinity [1], with the effect being qualitatively different for different types of confinement.  The behavior in systems containing different ratios of large-to-small silica nanoparticles is found intermediate between that of PEO/montmorillonite and that of PEO/silica with single-size particles; this behavior can be tuned by varying the ratio of large to small nanoparticles [2].  The dynamics of the confined polymer is probed by dielectric spectroscopy and quasi-elastic neutron scattering [3].  The very local dynamics of the confined chains show similarities with those in the bulk, whereas the segmental dynamics depend very strongly on the polymer/inorganic interactions [4] varying from much faster to much slower or even frozen dynamics [5] as the strength of the interactions increases.

#       This research has been co-financed by the General Secretariat for Research and Technology (Action KRIPIS), the European Union (NFFA Europe -grant agreement No. 654360) and the COST Action MP0902-COINAPO.

¥       In collaboration with K. Chrissopoulou, H. Papananou, K. Androulaki, S. Bollas, S. Fotiadou, E. Perivolari, I. Tanis, K. Karatasos, B. Frick, K. Andrikopoulos, G. A. Voyiatzis, M. Labardi, D. Prevosto

References

[1]     K. Chrissopoulou, K. Andrikopoulos, S. Fotiadou, S. Bollas, C. Karageorgaki, D. Christofilos, G. Voyiatzis and S. H. Anastasiadis, Macromolecules 2011, 44, 9710-9722.

[2]     H. Papananou, E. Perivolari, K. Chrissopoulou and S. H. Anastasiadis, in preparation (2017)

[3]     K. Chrissopoulou and S. H. Anastasiadis, Soft Matter 2015, 11, 3746-3766.

[4]     K. Androulaki, K. Chrissopoulou, D. Prevosto, M. Labardi and S. H. Anastasiadis, ACS Appl. Mater. Interfaces 2015, 7, 12387–12398.

[5]     S. Fotiadou, C. Karageorgaki, K. Chrissopoulou, K. Karatasos, I. Tanis, D. Tragoudaras, B. Frick and S. H. Anastasiadis, Macromolecules 2013, 46, 2842–2855.

 

Summary of academic career

Spiros H. Anastasiadis is a Professor of Polymer Science and Engineering at the Department of Chemistry of the University of Crete and the Director of the Institute of Electronic Structure and Laser of the Foundation for Research and Technology - Hellas. He holds a Diploma in Chemical Engineering (Aristotle University of Thessaloniki, 1983) and a Ph.D. in Chemical Engineering (Princeton University, 1988). He has been a Visiting Scientist at the IBM Almaden Research Center in 1988-1989 whereas he has been a Professor of Materials at the Department of Physics of the University of Crete (1993-2005) and a Professor of Materials Science and Engineering at the Aristotle University of Thessaloniki (2005–2008).  He was awarded the John H. Dillon Medal of the American Physical Society in 1998 and was elected Fellow of the American Physical Society in 2000.  He has received the Materials Research Society Graduate Student Award in 1987 and the Society of Plastics Engineers - Plastics Analysis Division Best Paper Award during ANTEC 1985.  He has been an Editor of the Journal of Polymer Science, Part B: Polymer Physics (5/2006-7/2010).  He served as a Consulting Editor for AIChE J. (8/2012-12/2016).  He is appointed as a Member of the Editorial Advisory Board of Macromolecules (1/2015-).  He is elected President of the European Polymer Federation for the period 2018-2019.  His research interests are in the areas of polymer surfaces/interfaces and thin films, polymer blends and homopolymer/copolymer blends, organic/inorganic nanohybrid materials, nanoparticulate catalysts within polymer matrices and responsive polymer systems.