Stability of a sharp uniaxial–isotropic phase interface

Abstract

We use a recently developed set of boundary conditions to study the stability of an interface between the uniaxial and isotropic phases of a nematic liquid crystal. In particular, we require satisfaction of director- and configurational-momentum balances imposed on the interface. Using linear analysis, we determine a stability condition for the moving interface and analyze the relevant marginal stability curves. We also study the effect of the front velocity and the stabilizing influence of the various dissipative mechanisms entering the theory on the perturbation growth-rate and wave-numbers. Cut-off wave-numbers arising from the analysis provide a short wave-length boundary for growing perturbations. The proposed theory describing instabilities of a uniaxial–isotropic interface in a system without impurities provides the limiting case for diffusion models driven by impurity gradients in the nematic and isotropic phases.