Effect of shear flow on Wormlike micelles

TL;DR

This study introduces a hybrid simulation method combining MPCD and molecular dynamics to analyze how shear flow influences the structure and phase transition of Wormlike micelles, revealing chain length variations and shear-induced breaking.

Contribution

The paper presents a novel hybrid simulation approach that captures hydrodynamic interactions and shear effects on equilibrium polymers at a mesoscopic scale.

Findings

Shear rate affects the order of the Iso-Nem transition.

Polymer chains initially grow longer with shear, then break at higher shear rates.

The method can be used to study shear banding and other properties of Wormlike micelles.

Abstract

We use a hybrid method that combines the Multiparticle collision dynamics (MPCD) for solvent particles with the molecular dynamics for equilibrium polymers to simulate the shearing of the equilibrium polymers (or Wormlike micelles) at a mesoscopic length scale. The MPCD method incorporates the hydrodynamic interaction with the polymeric chains. We show successful implementation of the method on the model equilibrium polymers (or Wormlike micelles) and observe that the order of the Iso-Nem transition of the polymeric system is affected by the shear rate. Moreover, the chains of the equilibrium polymers first increase in their average length with the increase in shear rate but then show a decrease in their average length after crossing a particular value of the shear rate which shows the breaking of chains due to shear stress when their nematic order remains unchanged. This model and method can be further used to investigate the shear banding in Wormlike micelles or other interesting properties of such systems.