Project Leader, Institute of Theoretical Physics, University of Munster, Germany

Biography: Alexander Chervanyov is a project leader in the Institute of Theoretical Physics at the University of Munster, Germany. He currently works on theoretical modeling of thermodynamic, mechanical and electrical properties of selected polymer-based nanocomposites. Alexander obtained his PhD from Kharkov National University, and subsequently worked in Pittsburgh University (2002-2003) and the University of Virginia (2003-2005) as a research associate. After moving to Germany, Alexander worked in Leibniz Institute of Polymer Research Dresden, where he has held the positions of guest scientist (2005-2007), staff scientist (2007-2011), and senior scientist (2011-2014). In the recent years, Alexander has been working on the theoretical description of effective interactions between nano-fillers mediated by different polymer systems and their effect on properties of these systems.

Speech Title: Polymer-mediated interactions and their role in the selected static and dynamical properties of polymer nano-composites
Aims: The main goal of the present work is to investigate the effective interactions between fillers mediated by polymers in different practically important polymer-nanoparticle composites, such as filled polymer melts, polymer blends, and rubbers. The derivative goal of immediate practical interest is to quantitatively understand the role of the polymer mediated (PM) interactions in the static and dynamical properties of the selected polymer-particle composites. Specifically, we address the effect of PM interactions on the coagulation-fragmentation of fillers and its effect on dynamic moduli, and the role of PM interactions in the piezoresistance observed in CNT-rubber composites.

Methods: Methods we use in our work are the self-consistent field theory, liquid state theory, potential theory developed by the author, and computer simulations. Theoretical results are compared against experimental work.

Results: We calculate the potential of the PM interactions in a variety of polymer systems, ranging from semi-dilute solutions to dense polymer melts and blends. Using the obtained PM potential, we calculate, in particular, the equation of state of filled polymer composites, equilibrium size distribution of flocs formed as a result of the shear induced coagulation-fragmentation of fillers, piezoresistive effect caused by the deformations of a host rubber containing conductive fillers.

Conclusions: We prove that the PM interaction play a key role in the above mentioned static and dynamical properties of the polymer-particle composites. We show that through changing the polymer – particle interactions it is possible to drive the associated PM forces and thus affect the macroscopic properties of the polymer nano-composites of practical interest.