Numerical Studies of Phase Separation in Models of Binary Alloys and Polymer Blends

We review some recent results concerning numerical studies of the CahnHilliard equation in three dimensions to describe the phase separation process in a mixture after a quench within the coexistence curve. We focus on the late time behavior for two experimentally relevant systems: binary alloys and binary polymer blends. We find that, in both systems, dynamical scaling with a time dependent characteristic length R ( t ) holds at sufficiently late times and that the late-time behavior for R(r ) can be described by a modified Lifschitz-Slyozov law: R( t ) = c + d f , where n = 1/3. For polymer mixtures, the independence of the growth law exponent n of the quench temperature is in contradiction with some recent experiments on polymer systems.