Dependence of the disorder-lamellar stability boundary of a melt of asymmetric wormlike AB diblock copolymers on the chain rigidity

We study the disorder-order transition boundary of wormlile AB diblock copolymers on the basis of the wormlike chain formalism aided by a self-consistent mean-field treatment. We examine the influence of the persistency on the phase diagram and properties of the phase transition as a function of the volume fraction, Flory-Huggins parameter, and relative chain rigidity, covering a broad regime spanning from the Gaussian chain to rigid rodlike chain. On the one hand, we demonstrate that the results from a Gaussian-weight-based theory can be recovered in the long-chain limit and, on the other hand, we display that significant revisions to the phase diagram, due to the persistency effects, exist for shorter chains. A split-step numerical algorithm is designed for the computational task.