A NUMERICAL STUDY OF THE LONG-TIME DYNAMI CS OF PHASE-SEPARATION DURING SPINODAL DECAY IN A BINARY POLYMER BLEND

The process of two-dimensional spinodal decay in a binary polymer blen d was studied by numerically solving the corresponding nonlinear diffu sion equation with a preset initial inhomogeneity. Evolution of the fr ee energy, composition distribution, and structural factor was analyze d for both a regular initial distribution (with the Fourier expansion containing a smalt number of harmonics) and a random distribution (mod eling typical inhomogeneities occurring in the system as a result of t hermal fluctuations), It is demonstrated that the formation of kinetic ally stable structures (characteristic of the one-dimensional case) in the two-dimensional case is encountered only in as narrow class of th e Initial distributions, In most cases of random realizations of the i nitial inhomogeneity, the evolution of inhomogeneity proceeds rather s moothly.