Supramolecular Self-assembly Behaviors of Asymmetric Diblock Copolymer Blends with Hydrogen Bonding Interactions between Shorter Blocks Modelled by Yukawa Potentials

We employed the extended self-consistent field theory to investigate the supramolecular self-assembly behaviors of asymmetric diblock copolymer blends (AB/B ' C) with hydrogen bonding interactions between shorter B and B ' blocks. The hydrogen bonding interactions are described by Yukawa potentials, where the hydrogen bonding donors and acceptors were modelled as two blocks smeared with opposite screened charges. The hierarchical microstructures with parallelly packed lamellae-in-lamellae (Lam) and 4.8.8 Archimedean tilting pattern (4.8.8) were observed at lower and higher hydrogen bonding density (theta), respectively. The hierarchy of Lam and 4.8.8 were demonstrated by the one- and two-dimensional density profiles and the underlying order of the large-length-scale and small-length-scale microstructures were also clarified. It was found that the 4.8.8 is favorable to the stronger hydrogen bonding density or interactions. As theta increases, the microphase transition from Lam to 4.8.8 occurs at theta=0.34, which is mainly attributed to the optimization of the electrostatic energy and conformational entropy with sacrificing the interfacial energy. This work can provide a new strategy to understand the supramolecular self-assembly as well as the mechanism behind the formation of complex hierarchical microstructures.