Binary Blends of Diblock Copolymers: An Effective Route to Novel Bicontinuous Phases

Abstract The formation of various bicontinuous phases from binary blends of linear AB diblock copolymers (DBCPs) is studied using the polymeric self‐consistent field theory. The theoretical study predicts that the double diamond and the “plumber's nightmare” phases, which are metastable for neat DBCPs, could be stabilized in block copolymers with designed dispersity, namely, binary blends composed of a gyroid‐forming DBCP and a homopolymer‐like DBCP. The spatial distribution of different monomers reveals that these two types of DBCPs are segregated such that the homopolymer‐like component is localized at the nodes to relieve the packing frustration. Simultaneously, the presence of a local segregation of the two DBCPs on the AB interface regulates the interfacial curvature. These two mechanisms could act in tandem for homopolymer‐like DBCPs with proper compositions, resulting in larger stable regions for the novel bicontinuous phases.