초록 |
Higher ordered structures of block copolymer have received much attention because of their unique structure. Among them, the design and synthesis of helical structures are becoming increasingly important because they are applied to the heterogeneous catalyst, optical sensor and plasmonic systems. In this work, we investigated, via SAXS and TEM, the morphologies of polystyrene-b-polyisoprene-b-polystyrene-b-poly(2-vinylpyridine) (S1IS2V, 100k) tetrablock terpolymer. Very interestingly, When the volume fractions were 0.668,0.12,0.077 and 0.135 respectively, We discovered helix-in-helix structure that consists of twisted core cylinder and a double-stranded helix surrounding it, and the twisted core cylinder and double-stranded helix are P2VP, PI respectively. The experimentally observed morphologies are in good agreement with the predicted equilibrium phases by self-consistent filed theory (SCFT). |