Self-assembly of T-shaped rod-coil block copolymer melts

Self-assembled behavior of T-shaped rod-coil block copolymer melts is studied by applying self-consistent-field lattice techniques in three-dimensional space. Compared with rod-coil diblock copolymers with the anchor point positioned at one end, the copolymers with the anchor point at the middle of the rod exhibit significantly different phase behaviors. When the rod volume fraction is low, the steric hindrance of the lateral coils prevents the rods stacking into strip or micelle as that in rod-coil diblock copolymers. The competition between interfacial energy and entropy results in the formation of lamellar structures and the increasing thickness of the lamellar layer with increasing rod volume fraction. When the rod volume fraction is high, the graft density of the planar interface is decreased, which results in space-filling requirements and stretching penalty, thus leading to the stability of nonlamellar structures with curing interface. Furthermore, our results also suggest that the effect of the chain architecture on the self-assembled behavior is remarkable when the rod volume fraction is low, whereas the effect is weak when the rod volume fraction is high.