DYNAMICS OF CROSSOVER FROM DIFFUSION GROWTH TO COARSENING IN QUENCHEDBINARY-MIXTURES

The effect of a high volume fraction on the dynamics of phase separati ons in off-critically quenched binary mixtures, such as binary alloys and polymer blends, is discussed from a new unifying point of view. Th ree characteristic stages are shown to exist after the nucleation stag e. The first is the early stage [E] where the droplets grow directly a nd independently from the solution by diffusion. The second is the int ermediate stage [I], where the growth is no longer independent due to the three kinds of interactions among droplets; the many-body interact ion, the coagulation, and the Ostwald ripening. The third is the coars ening stage [C] where the growth from the solution is over. The dynami cal behavior of phase separations is investigated analytically through the whole stages, including the dynamical scaling behavior, time expo nents, and crossover. The numerical simulation is also performed to co nfirm the theoretical prediction.