Side Chain Induced Morphology Changes in Brush-Linear Diblock Copolymers
발표자
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초록
내용
Brush-linear block copolymer is interesting class of material as they exhibit complex phase morphology. In this study, we investigate the self-assembly of brush-linear block copolymers where both the brush side chain density and chain length are systematically varied. A poly(pentafluorophenyl acrylate-b-styrene) (PPFPA-b-PS) block copolymer is prepared. The PPFPA block is reacted with amine-functionalized poly(ethylene glycol) (PEG) to create brush-linear block copolymers, (PPFPA-g-PEG)-b-PS. Different degrees of PEG substitution are conducted, and the morphology of resulting brush-linear block copolymers are examined by small-angle X-ray scattering. As the degree of PEG substitution increases, block copolymer morphology is found to transition from lamellae to a newly formed frustrated lamellae then to hexagonally-packed cylinder. When longer PEG chains are used, the same morphology transition is observed while these transitions occur at even lower degrees of side-chain substitution.