Multi-chain slip-spring simulations with various slip-spring densities

TL;DR

This study systematically investigates how slip-spring density affects multi-chain slip-spring simulations of entangled polymers, revealing universal behaviors in diffusion and viscoelasticity that align with experimental data.

Contribution

It demonstrates that the MCSS model exhibits universal behavior across various slip-spring densities, allowing flexible coarse-graining similar to the Rouse model.

Findings

Universal superposition of diffusion and viscoelasticity results across slip-spring densities

Good agreement with literature data for molecular weight dependence

Universality persists under mild shear conditions

Abstract

Although it has been established that the multi-chain slip-spring (MCSS) model can reproduce entangled polymer dynamics, the effects of model parameters have not been fully elucidated yet. In this study, we systematically investigated the effects of slip-spring density. For the diffusion and the linear viscoelasticity, the simulation results exhibited universality. Namely, the results from the simulations with various slip-spring densities can be superposed with each other by the conversion factors for the bead number per chain, unit of length, unit of time, and modulus. The diffusion and the viscoelasticity were in good agreement with the literature data for the standard bead-spring simulations, including the molecular weight dependence. The universality among the MCSS simulations with various slip-spring density also held under mild shear if the slip-spring density was not significantly high. The results imply that the level of coarse-graining for the MCSS model can be arbitrarily chosen as in the Rouse model.