Multiscale modeling of simple and polymeric liquids

Martin Kroeger

Institute for Polymers ETH Zurich, Switzerland

A) I will offer an introduction to the so-called beyond-equilibrium molecular dynamics method which requires and recognizes a separation of time scales. The method is of particular use for the study of nonequilibrium molecular dynamics subject to weak external fields, a regime usually difficult to access using brute-force simulation approaches.

B) A method similar in spirit, the so called quasi equilibrium approximation, will be used to obtain 'macroscopic' equations for the theoretical description of ferrofluids and liquid crystals starting from a 'mesoscopic' description. For these systems, we also discuss on how closure relationships with correct tensorial symmetry lead to closed nonlinear equations for the orientation tensor, and offer a nonequilibrium phase diagram.

C) As long as there will be no overlap with the presentations by Vlasis Mavrantzas or Ronald G. Larson, I will report on recent developments in the identification and analysis of 'tubes' from atomistic and mesoscopic simulations of polymer melts.

D) Eventually, I may present some recent modifications of the smooth particle dynamics method to incorporate viscoelasticity by treating the stress tensor as a dynamical variable.