Dynamical Coarse-Graining of Highly Fluctuating Membranes under Shear Flow

TL;DR

This paper investigates how strong shear flow influences highly fluctuating lamellar membranes, revealing a shear-dependent tension effect that impacts their stability and dynamics.

Contribution

It introduces a novel dynamical coupling term in the coarse-grained theory, showing how shear flow modifies membrane stability through a wavevector-dependent tension.

Findings

Shear flow induces a non-linear, wavevector-dependent tension in membranes.

The new tension term affects the stability of lamellar phases under shear.

Flow alters membrane dynamics, potentially leading to phase destabilization.

Abstract

The effect of strong shear flow on highly fluctuating lamellar systems stabilized by intermembrane collisions via the Helfrich interaction is studied. Advection enters the microscopic equation of motion for a single membrane via a non-linear coupling. Upon coarse-graining the theory for a single bilayer up to the length scale of the collision length, at which a hydrodynamic description applies, an additional dynamical coupling is generated which is of the form of a wavevector-dependent tension that is non-linear in the applied shear rate. This new term has consequences for the effects of strong flow on the stability and dynamics of lamellar surfactant phases.