Dynamics of phase separation in a binary polymer blend of critical composition

Abstract

We report results of a detailed numerical study of the phase separation process in a three dimensional model of polymer blends. The model system considered by us is described by Flory–Huggins–de Gennes free-energy functional. For a critical quench, we numerically integrate the corresponding time evolution equation for the conserved order parameter based on the above free-energy functional. We study the time dependence of the characteristic domain size as well as the pair correlation function and the structure factor for several quench temperatures. The results indicate that the growth law for the characteristic domain size is given by a modified Lifshitz–Slyozov law and the growth law exponent is independent of the quench temperature. We also find that both the pair correlation function and the structure factors show dynamical scaling at late times.