Multiscale equilibration of highly entangled isotropic model polymer melts

Abstract

We present a computationally efficient multiscale method for preparing equilibrated, isotropic long chain model polymer melts. As an application we generate Kremer-Grest melts of $1000$ chains with $200$ entanglements and $25000$-$2000$ beads per chain, which cover the experimentally relevant bending rigidities up to and beyond the limit of the isotropic-nematic transition. In the first step, we employ Monte Carlo simulations of a lattice model to equilibrate the large-scale chain structure above the tube scale while ensuring a spatially homogeneous density distribution. We then use theoretical insight from a constrained mode tube model to introduce the bead degrees of freedom together with random walk conformational statistics all the way down to the Kuhn scale of the chains. This is followed by a sequence of simulations with carefully parameterized force-capped bead-spring models, which slowly introduce the local bead packing while reproducing the larger scale chain statistics of the target Kremer-Grest system at all levels of force-capping. Finally we can switch to the full Kremer-Grest model without perturbing the structure. The resulting chain statistics is in excellent agreement with literature results on all length scales accessible in brute-force simulations of shorter chains.

Revised manuscript. Submitted to Journal of Chemical Physics

References in corpus (8)

• Representability problems for coarse-grained water potentials
• Intramolecular long-range correlations in polymer melts: The segmental size distribution and its moments
• Viscoelasticity and primitive path analysis of entangled polymer liquids: From f-actin to polyethylene
• Equilibration of High Molecular-Weight Polymer Melts: A Hierarchical Strategy
• Intramolecular Form Factor in Dense Polymer Systems: Systematic Deviations from the Debye formula
• Local loop opening in untangled ring polymer melts: A detailed "Feynman test" of models for the large scale structure
• One size fits all: equilibrating chemically different polymer liquids through universal long-wavelength description
• Facile equilibration of well-entangled semiflexible bead-spring polymer melts

Cited by in corpus (1)

• DNA supercoiling in bacteria: state of play and challenges from a viewpoint of physics based modeling