Mesoscale Simulations of Liquid Crystalline Diblock Copolymers

Side-chain liquid crystal (SCLC) diblock copolymers possess the characteristics of both block copolymers and liquid crystalline polymers, a combination that makes them useful for membrane separation applications and as responsive materials. Currently, there are a lack of coarse-grained molecular models that effectively capture block copolymer self-assembly and ordering of liquid crystals. We have developed a mesoscale model that we are using to study both isotropic-to-nematic and order-disorder phase transitions of SCLC diblock copolymers. We have studied the interference between the order to disorder transition of the block copolymer phases and the isotropic to nematic transition of the liquid crystal phases, finding that the nematic phase suppresses the formation of phases without at least one direction of symmetry. Additionally, we characterize how the chain conformations change as we move through the phase transitions, finding that the orientation of the chains relative to the nematic director changes as a function of the polymer composition.