Simulation of Chain Exchange Between Ordered Block Copolymer Micelles: Influence of Chain Architectures

We examine kinetics of chain exchange of block copolymers between body-centered cubic ordered spherical micelles, focusing on the influence of chain architectures. We compare linear AB, ABA and BAB block copolymers using dynamical self-consistent field theory simulations. We connect equilibrium properties such as micelle aggregation number, unimer fraction and micelle volume to chain exchange kinetics. The effects of different equilibrium structures on chain exchange are found by measuring the chain exchange of labelled chains and chain self-diffusion for pure melts of each chain architecture. To eliminate influences of equilibrium structure on dynamics, we perform simulations of tracer triblocks in a constant array of micelles formed by AB diblocks. Comparisons of the tracer diffusion coefficients show that BAB triblocks diffuse faster, due to the looping of the core block at the micelle core-corona interface, than AB diblocks while ABA triblocks diffuse slower than AB diblocks due to the additional core block.