Semidilute Polymer Solutions at Equilibrium and under Shear Flow

TL;DR

This paper uses mesoscale simulations to study the behavior of semidilute polymer solutions at equilibrium and under shear flow, revealing how concentration affects polymer properties and flow responses.

Contribution

It introduces a combined molecular dynamics and multiparticle collision dynamics approach to analyze polymer solutions, providing new insights into their flow and equilibrium properties.

Findings

Good agreement with scaling predictions for equilibrium properties

Polymer alignment and deformation depend on concentration under shear

Shear thinning linked to flow alignment and polymer extensibility

Abstract

The properties of semidilute polymer solutions are investigated at equilibrium and under shear flow by mesoscale simulations, which combine molecular dynamics simulations and the multiparticle collision dynamics approach. In semidilute solution, intermolecular hydrodynamic and excluded volume interactions become increasingly important due to the presence of polymer overlap. At equilibrium, the dependence of the radius of gyration, the structure factor, and the zero-shear viscosity on the polymer concentration is determined and found to be in good agreement with scaling predictions. In shear flow, the polymer alignment and deformation are calculated as a function of concentration. Shear thinning, which is related to flow alignment and finite polymer extensibility, is characterized by the shear viscosity and the normal stress coefficients.