Preparation of amphiphilic triblock copolymer brushes for surface patterning

摘要

This paper describes the formation of poly(methyl methacrylate)b-poly(dimethylamino ethylmethacrylate)-b-poly(methyl methacrylate) (PMMA-b-PDAEMA-b-PMMA) and poly(methyl acrylate)-b-poly(methyl methacrylate)-b-poly(hydroxyethyl methacrylate) (PMA-b-PMMA-b-PHEMA) brushes and phase segregation by these materials upon exposure to a poor solvent for the outer block. Synthesis of the brushes employs room-temperature atom-transfer radical polymerization from a surface, and formation of multiblock copolymers simply involves changing the monomer solution that surrounds the substrate. Phase segregation by both types of triblock brushes in the presence of a poor solvent for the outer block results in surface domains that are about 50 nm in diameter. Sizes of domains are more uniform with PMMA-h-PDAEMA-b-PMMA than PMA-b-PMMA-b-PHEMA, but this may be specific to the solvent treatments employed for the two polymers. Formation of nanodomains by triblock copolymers appears to be a widespread phenomenon.