Effects of chain architectures on the surface structures of conjugated rod-coil block copolymer brushes

Rod-coil block copolymers are of unique and interesting characteristics since their physical properties can be reversibly tuned in response to the external stimuli, such as change in solvent quality. In this study, dissipative particle dynamics is used to investigate the surface structures of rod-coil polymer brushes tethered onto a surface. When immersed in the selective solvent for the coil blocks, rod blocks tend to form aggregates. Our results show that linear and Y-shaped polymer brushes exhibit similar aggregative behavior. However, some of the surface structures can be acquired within experimentally attainable surface grafting density only for Y-shaped polymer brushes. On the other hand, comblike polymer brushes are found to possess more diverse aggregative manners than linear brushes. Surface structures with aggregates taking the forms of cones, cylinders, or layers of spheres are found. By controlling the aggregative structures, it is possible for us to adjust the physical properties, such as optical function, of the material.