Self-assembly in conjugated diblock copolymer in melt

The structural changes of a series of rod-like diblock copolymers with different conjugation lengths of oligo(pheneylene vinylene) and oligothiophene were studied by small-angle x-ray scattering. These rod-rod types of diblock copolymers self-assemble into the different lamellar structures on the nanometer scale, depending upon the conjugation lengths of OPV block. The results demonstrate that the thermal treatment plays a significant role in determining the structures for each copolymer. More specifically, it is shown that the annealing time required for each copolymer to reach the equilibrium state depends on the length of OPV block. The length of OPV block is a key parameter in controlling the long-range feature in OPV-OT diblock copolymers as well.