Monte Carlo study of phase separation in critical polymer blends

Dynamics of phase separation in a polymer blend of critical composition is studied by Monte Carlo simulation of a microscopic lattice model. We find that dynamical scaling is obeyed by both the correlation function and the structure factor at late enough times, and that the asymptotic domain growth exponent is given by a modified Lifshitz-Slyozov law. We also compare the shape of the scaling function to the one previously obtained in a numerical study using a phenomenological Flory--Huggins--de Gennes free-energy functional.