| 초록 |
We synthesized polystyrene-[polystyrene-b-poly(2-vinylpyridine)]3 miktoarm star copolymer [PSL-(PSS-b-P2VP)3] where PSL and PSS are long and short PS chains, respectively, by the combination of anionic polymerization, ATRP, and click reaction. We changed the volume fraction of PS block (ƒPS) and the chain asymmetry of PS chain (τ=ƒPS,L/(ƒPS,L+ƒPS,S). Phase behavior of PSL-(PSS-b-P2VP)3 was investigated by TEM and SAXS. Inverted gyroids consisting of PS chains were formed at ƒPS=0.64 and τ=0.65, while, asymmetric lamellae were observed at ƒPS=0.81 and τ=0.79. Interestingly, the phase behavior was greatly affected by τ at a fixed ƒPS. For instance, at a fixed ƒPS (0.64), inverted gyroid was formed at τ=0.65, while asymmetric lamellae was observed at τ=0.46. With decreasing τ (or the difference of molecular weight between PSL and PSS becomes smaller), interfacial curvature is not expected, because all PSS-b-P2VP chains have no need to arrange into the same direction. |
