Phase separation process and its dynamics play an important role in the preparation of many polymeric materials (such as high-impact plastics and synthetic membranes for separations). They affect the morphology, which, in turn, influences ultimate material properties. Over the last three decades, increasing attention has been paid to this subject, the majority of research concentrating on initial stages of phase separation using the linearized Cahn-Hilliard model. Such an analysis cannot provide the full answer; it ignores the later stages of phase separation, which in many cases is crucial for the determination of the resulting structure. Using the nonlinear Cahn-Hilliard theory and fluid dynamic methods, the investigator will study primarily the later processes, such as coarsening (Ostwald ripening) and hydrodynamic flow, with the earlier stages serving to generate the initial conditions for the later ones. The roles of nucleation and thermal random force in the phase-separation process will also be studied. The recent progress in handling the phase equilibria of ternary and higher systems, and the access to supercomputers to simulate the time-demanding multidimensional diffusion and hydrodynamic processes involved, will make it feasible to carry out this complex task.
