Pattern Evolution Induced by Periodic Temperature Modulation in a Binary Polymeric Mixture

摘要: The process of periodic phase separation is numerically studied based on Cahn-Hilliard-Cook theory for a binary polymer blend. model system quenched blow and above the critical point alternatively. And hierarchic morphologies consisting large small domains are observed. As proceeds, created destroyed periodically, whereas keep growing. Within first half each period, behavior similar to two-step separation. quench one-phase region during second period not only decreases peak intensity structure function domains, but also eliminates high-wave number corresponding domains. average order parameter under oscillatory quenches exhibits behavior. minimum in approaches its equilibrium value monotonously maximum increase early time regime decrease late regime. magnitude oscillation has considerable effects evolution structures. Small hinders formation morphologies. Moreover, slows down coarsening stage accelerates growth In addition, no scaling invariance could be observed net