Single Crystal Engineering of Diblock Copolymer Brushes

In the past two decades, research of polymer brushes have been substantially progressed not only due to scientific interest but also because of its potential application. Usually, physical absorption, ``grafting to'' and ``grafting from'' methods have been used to fabricate them on solid substrate. During these processes, how to achieve uniform tethering density and narrow molecular weight distribution of the tethered chains are always challenges for the experimental efforts. Recently we have proposed a novel method by using amorphous-crystalline block copolymers. Here I would like to report another system of triblock copolymer with one crystalline block at one end, PMMA-PS-PLLA. By using self-seeding technique, we can create tethered diblock copolymer PMMA-PS brushes on the basal planes of PLLA single crystal. The morphology changes of the diblock copolymer brushes with treatments by different solvents and tethering densities which can be precisely controlled by changing crystallization temperature and quality of solvents have been studied. Furthermore, the surface topologies can be enhanced by etching PMMA blocks away using UV light.