Polymer Crystallization Confined in Hard Spherical Microdomains of Diblock Copolymers

We report dynamic Monte Carlo simulations of crystallization under hard confinement of spherical diblock copolymers. We compared the parallel results of blocks with short chains made by breaking block,junctions. We observed that blocks crystallize faster but harvest lower crystallinity than short chains, which is in agreement with recent experiments. We found that the fast crystallization can be assigned to the slightly stretched blocks, and the lowered crystallinity is mainly attributed to the frozen block junctions near interfaces. In addition, homogeneous crystal nucleation at low temperatures switches Avrami indexes of both cases from one (first-order kinetics) to 0.5 and meanwhile ruins uniform crystal orientations inside each microdomain. Our present results may facilitate our better understanding of the fabrication of polymer nanocrystals through self-assembly of diblock copolymers.