초록 |
Block copolymers in a dilute solution of a solvent selective for one block self-assemble into nanometer-sized spherical micelles, consisting of insoluble cores and soluble coronas. We investigated various complex nanostructures in thin films of micellar mixtures of PS-P4VP and PS-P2VP diblock copolymers by solvent vapor treatment. When the micellar film of mixtures was exposed to THF vapor, which is a selective solvent for the PS block in PS-P4VP copolymers and a neutral solvent for both blocks in PS-P2VP copolymers, the PS-P2VP micellar structure was converted to the cylindrical nanostructure but the PS-P4VP micellar structure remained without structural alteration. We were able to induce various complex nanostructures of PS-P4VP and PS-P2VP by controlling of size and weight ratios of two copolymers. Nanostructures in thin films were visualized by atomic force microscopy and transmission electron microscopy. |