Grain boundary defects in block copolymer systems: Bulk and thin film results

Abstract

Abstract Ordered periodic morphologies are the hallmark of most discussions of the microphase‐separated state in block copolymer systems yet actual materials contain a myriad of defects. Perhaps the most important of these defects are those which constitute the regions between ordered grains. Transmission electron microscopy (TEM) is used to investigate the grain boundary morphology of diblock copolymers in both bulk and thin film geometries. These experiments show that constant mean curvature (CMC) surfaces are often useful descriptors, not only for the equilibrium morphology of microphase‐separated copolymers, but also for the microphase‐separated morphology within grain boundaries.