Phase separation in binary mixtures confined in a strip geometry

Abstract

We study the kinetics of phase separation of a model binary fluid confined within a narrow strip in two dimensions by numerically integrating the Cahn-Hilliard-Cook equation. We explore the systematics of the time evolution of domain shapes as a function of temperature and wetting field. The domains exhibit similar configurations as seen in recent Monte Carlo simulations of a related lattice model. We provide a quantitative estimate of the breakdown of power-law growth of domains once the domain size becomes comparable with the strip width, and show the relevance of the model to domain growth in Vycor glasses. Next we argue for the incorporation of an anisotropic kinetic coefficient in the coarse-grained dynamical equations. We find that even the slightest amount of anisotropy modifies the shapes of domains drastically and allows for complete phase separation.