We demonstrate the structural reorganization of microdomain arrays toward the perpendicular orientation of lamellar morphology in high-molecular-weight PS-b-PMMA films using a combinational approach by solvent-vapor and sequential thermal annealing processes. Solvent annealing with a PMMA-selective acetone vapor induced a cylindrical morphology. However, the sequential thermal annealing of block copolymer (BCP) films led to structural reorganization to an equilibrium lamellar morphology, where the lamellar microdomains were oriented to normal to the film surface. This technique suggests an efficient route for directing orientation and structural reorganization of microdomain arrays in the thin films of high-molecular-weight BCP self-assembly.
Giant Gyroid and Templates from High-Molecular-Weight Block Copolymer Self-assembly
