Self-Consistent Field Theory Predicts Universal Phase Behavior for Linear, Comb, and Bottlebrush Diblock Copolymers

We use self-consistent field theory (SCFT) to map phase boundaries between periodic microphases for linear, comb-like, and bottlebrush diblock copolymers with continuous Gaussian, discrete Gaussian, and freely jointed chain statistics. By using a properly defined asymmetry parameter, composed of a variety of architectural parameters including side-chain length and segment length, we obtain a universal phase diagram for sphere phases that include A15 and sigma phases. We do not observe a transition from comb-like to bottlebrush scaling with architectural parameter variation, which we attribute to the mean field approximation of SCFT.