Wall-anchored semiflexible polymer under large amplitude oscillatory shear flow

TL;DR

This study uses mesoscale simulations to explore how tethered semiflexible polymers respond to large amplitude oscillatory shear flow, revealing nonlinear conformational changes and unique frequency doubling effects.

Contribution

It provides new insights into the nonlinear dynamics and conformational behavior of wall-anchored semiflexible polymers under oscillatory shear, using a combined bead-spring and multiparticle collision dynamics model.

Findings

Polymers stretch and form U-shapes at high strains.

A frequency doubling occurs in properties normal to the wall.

Nonlinear conformational changes dominate at large strains.

Abstract

The properties of semiflexible polymers tethered by one end to an impenetrable wall and exposed to oscillatory shear flow are investigated by mesoscale simulations. A polymer, confined in two dimensions, is described by a linear bead-spring chain, and fluid interactions are incorporated by the Brownian multiparticle collision dynamics approach. At small strains, the polymers follow the applied flow field. However, at high strain, we find a strongly nonlinear response, with major conformational changes. Polymers are stretched along the flow direction and exhibit U-shaped conformations while following the flow. As a consequence of confinement in the half-space, a frequency doubling in the time-dependent polymer properties appears along the direction normal to the wall.