Hierarchically ordered microstructures self-assembled from comb-coil block copolymers.

Using the real-space implemented self-consistent field theory, we undertook an investigation on the hierarchical self-assembly behaviors of comb-coil block copolymers. The comb-coil block copolymers can self-assemble into hierarchical microstructures with two different length scales. Various structure-within-structure morphologies, such as parallel and perpendicular lamella-within-lamella, cylinder-within-lamella, lamella-within-cylinder, and cylinder-within-cylinder, were observed. In the hierarchical structures, the large-length-scale structures are produced by segregation between the coil blocks and comb blocks, and the small-length-scale structures are formed by microphase separation within the comb blocks. Effects of interaction strength and coil block length on the hierarchical phase behaviors were studied, and the phase diagram was mapped out accordingly. Furthermore, the large-length-scale lamellar period as a function of interaction strength was examined. It was found the lamellar periods are greatly dependent on interaction strengths.