Research Activities >
Programs >
Complex Fluids 2007
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Thermodynamically guided atomistic Monte
Carlo simulation of polymer melts beyond
equilibrium
CSIC Building (#406),
Seminar Room 4122.
Directions: home.cscamm.umd.edu/directions
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Thermodynamically guided atomistic Monte Carlo
simulation of polymer melts beyond equilibrium
Professor
Vlasis Mavrantzas
FORTH-ICE/HT & Department of Chemical Engineering,
University of Patras, Patras, Greece
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Abstract:
We present a new simulation methodology which has a
great potential for investigating the
viscoelasticity of long chain polymeric liquids of
relevance even to systems and conditions used in
practical polymer processing operations. The main
idea of the new scheme is to combine two different
thermodynamically-founded simulation algorithms:
GENERIC (General Equation for the Nonequilibrium
Reversible-Irreversible Coupling) Monte Carlo (MC)1,2,3
and NEMD (Nonequilibrium Molecular Dynamics).4
With this new methodology, we are able to
relate properly chosen state variables representing
nonequilibrium states of the system of interest in
the frame of the GENERIC formalism to the
corresponding real, physical variables that directly
bring about the same nonequilibrium states. We
achieve this by taking first advantage of GENERIC MC
to drive quickly the simulated system to certain
nonequilibrium (but steady-) states of interest, and
by performing next NEMD simulations to obtain all
the important dynamical information of the
nonequilibrium states. As a simple test case, we
have applied this new scheme first to a relatively
short chain, linear polyethylene melt, and results
will be presented for its response to a given flow
field. More importantly, it is expected that our new
methodology (when properly incorporated within a
coarse-grained modeling scheme) would make it
possible to efficiently study the true reptation
regime of polymer melts.
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