Single chain in mean field (SCMF) simulation of flexible and semiflexible block copolymers

Abstract

Self-consistent field theory (SCFT) has been a popular tool for the study of equilibrium properties of block copolymer nanostructures. It is a mean field theory, and thus it has limitations in that fluctuation effects are ignored. One suggestion to incorporate fluctuations into the field theoretical calculation is the single chain in mean field (SCMF) simulation which performs explicit Monte Carlo simulation of polymer chains under quasi-instantaneously updated self-consistent field. In this research, we perform SCFT calculation and SCMF simulation of block copolymers in thin film morphology. For the symmetric block copolymers, the phase transition is suppressed when confined by two neutral walls, and the surface-perpendicular lamellar phase becomes slightly preferable to the surface-parallel one. We also perform SCMF simulation of semiflexible polymer chains by adopting angle dependent potential in both bead-spring and freely-jointed chain model, and our results reveal that stiffer chains exhibit higher tendency to self-assemble into ordered structures. For the confined system, it turns out that the surface-perpendicular lamellar phase becomes more stable as the stiffness of the chain increases.