Dresden 2017 – wissenschaftliches Programm
CPP 16.1: Poster
Montag, 20. März 2017, 18:30–21:00, P1C
Kinetic properties of liquid crystals from coarse-grained and atomistic molecular dynamics simulations — •Svenja Wörner, Joseph Rudzinski, Kurt Kremer, and Tristan Bereau — Max-Planck-Institut für Polymerforschung, Mainz, Germany
Liquid crystals display liquid-like behavior while maintaining a long-range crystalline order, giving rise to unique material properties. To understand macroscopic processes, e.g. phase transitions, large systems need to be studied on time scales not accessible by atomistic models. Coarse grained models make these sizes and time scales accessible.
In this work we investigate the liquid crystal mesogen 8AB8, containing a stiff, photoisomerizable azobenzene core with flexible alkyl tails. Mukherjee et al. have previously developed a coarse-grained model of 8AB8, which displays the correct thermodynamic and structural properties. Not only is it able to form a smectic phase, the model also reproduces the transition temperature of the disordered to smectic phase transition of the underlying atomistic model. Reducing the degrees of freedom usually leads to a non-trivial modification of the timescales for different processes sampled by the coarse-grained model. Two well-characterized translocation pathways in the smectic A phase are studied in detail, utilizing a Markov state model framework to systematically assess the differences in the transport kinetics between the coarse-grained and atomistic models. Investigating the precise source of the discrepancies between the two models implicates an approach for reparametrization of the coarse-grained model.