Emergence and Stability of a Hybrid Lamella–Sphere Structure from Linear ABAB Tetrablock Copolymers

The self-assembly of linear A₁B₁A₂B₂ tetrablock copolymers is studied using the self-consistent field theory, aiming to target the formation of stable hybrid structures composed of lamellar and spherical domains of the same component, i.e., the lamella-sphere (LS) phase. Two types of lamellar morphologies, regular (L) and sandwich-like (L'), are observed, and their transition is identified as first-order. The formation of L' is a prior …