Microphase separation in block copolymers

Block copolymers have been the focus of intense scientific and commercial development because of their ability to organize into precise structures on the scale of ten to one hundred nanometers. The wide variety of morphologies exhibited by linear block copolymers made from two chemically distinct monomers has been extensively studied over many years and is now fairly well understood. Three extensions of these studies have uncovered new classes of structures and new relations between copolymer composition and morphology. These include block copolymers with a nonlinear chain architecture, linear terpolymers with three chemically different blocks, and mixtures of linear diblocks with molecular weight or compositional differences. These results have greatly expanded the range of domain sizes and types of morphology that can be found in block copolymer materials.