Non-lamellae structures of coil–semiflexible diblock copolymers

Abstract

We investigate the self-assembly of coil–semiflexible block copolymers in 2D positional space by using self-consistent field theory (SCFT) based on the wormlike chain model for the semiflexible block and the Gaussian chain model for the coil block. A highly accurate and efficient operator splitting pseudospectral algorithm is adopted to cope with the computational intricacy of solving modified diffusion equations for the propagators of wormlike chains. Within the framework of anisotropic Maier–Saupe orientational interactions and isotropic Flory–Huggins interactions, the phase diagram including isotropic, smectic-C, and further appended non-lamella structures is constructed for the coil–semiflexible block copolymers in the region of coil volume fractions from 0.6 to 0.8. Hexagonal packed pucks and rhombic pucks formed by the semiflexible block with major orientation perpendicular to their nearest neighbors in the latter are discovered at relatively high coil fractions and strong orientational interactions. We also study the influence of chain rigidity on the phase behavior of coil–semiflexible block copolymers.