Compositional domain dynamics in two-coupled lipid monolayer: A mean field approximation approach

Abstract

A continuum model for artificial membrane was developed by treating the upper and lower layers of the membrane as a pair of coupled Ising monolayers. Linear coupling between the layers was included. Linear stability analysis was used to predict the phase diagram. The dependence of the phase-separated regions on inter-layer coupling is determined. We numerically solve the Cahn-Hilliard type equations to obtain domain evolutions for both layers. The estimations of the coupling strengths between the bilayers are determined from simulations. The dynamic scaling of the characteristic domain sizes for the symmetric and asymmetric cases are also evaluated from the simulations. Unique domain-growth scaling is reported in both cases. Key words: Lipid bilayers, domain coarsening dynamics, mean-field approximation, inter-layer coupling estimation.