Analytical Rescaling of Polymer Dynamics from Mesoscale Simulations

TL;DR

This paper introduces an analytical method to accurately rescale the artificially accelerated dynamics in coarse-grained polymer simulations, aligning them with real-world behavior by accounting for entropy and dissipation effects.

Contribution

The authors develop a general, transferable analytical rescaling approach that corrects polymer dynamics from mesoscale simulations to match experimental data.

Findings

Quantitative agreement with united atom simulations

Successful application to polyethylene melts

Effective correction for entropy and dissipation effects

Abstract

We present a theoretical approach to scale the artificially fast dynamics of simulated coarse-grained polymer liquids down to its realistic value. As coarse-graining affects entropy and dissipation, two factors enter the rescaling: inclusion of intramolecular vibrational degrees of freedom, and rescaling of the friction coefficient. Because our approach is analytical, it is general and transferable. Translational and rotational diffusion of unentangled and entangled polyethylene melts, predicted from mesoscale simulations of coarse-grained polymer melts using our rescaling procedure, are in quantitative agreement with united atom simulations and with experiments.