title: The effect of shear flow on the Helfrich interaction in lyotropic lamellar systems.
abstract: We study the effect of shear flow on the entropic Helfrich interaction in lyotropic surfactant smectic fluids. Arguing that flow induces an effective anisotropic surface tension in bilayers due to a combination of intermonolayer friction, bilayer collisions and convection, we calculate the reduction in fluctuations and hence the renormalised change in effective compression modulus and steady-state layer spacing. We demonstrate that non-permeable or slowly permeating membranes can be susceptible to an undulatory instability of the Helfrich-Hurault type, and speculate that such an instability could be one source of a transition to multilamellar vesicles.
authors.affiliation: Polymer IRC and Department of Physics & Astronomy, University of Leeds, Leeds LS2 9JT, UK. physwm@irc.leeds.ac.uk
authors.forename: S W
authors.initials: SW
authors.lastname: Marlow
authors.forename: P D
authors.initials: PD
authors.lastname: Olmsted