Interfacial effects and topological architecture synergistically govern three-dimensional self-assembly morphology of polyethylene-based block copolymers.

Abstract

While block copolymers (BCPs) readily achieve 1D/2D architectures through crystallization-driven self-assembly (CDSA) in solution, assembling of 3D nanostructures faces thermodynamic and kinetic constraints. To address this, we optimized thermodynamic parameters and kinetic protocols in solvent vapor annealing (SVA) for high-melting polyethylene-based BCPs, enabling investigation of synergistic interfacial and topological roles in phase separation and crystallization pathways. A systematic comparison of the topological structures indicates that substrate-induced interfacial energy minimization is a driving force for the formation of multilayered equilibrium structures, whereas chain topology dictates both chain mobility and interfacial interaction strength. Atomic force microscopy further demonstrates that prolonged single-step annealing yields 3D lamellae dominated by the influence of interfacial effects. Conversely, multi-cycle annealing facilitates morphological evolution from low-dimensional aggregates to 3D cubical crystallites under combined topology/interface effects, establishing a pathway for hierarchical structure control.