Alignment of microdomain in structures of block copolymers by dip-coating method

Polyisoprene(I)-poly(2-vinylpyridine)(P) block copolymer films were prepared by dip-coating method from dioxane and toluene solutions, which are selective solvents for P and I components, respectively. Some of the thin films prepared from dioxane solution were subsequently dipped in toluene solution and then coated. Surface structures of the thin films were evaluated by atomic force microscopic observation. For the thin film prepared by a double dip-coating method using dioxane and toluene solutions, highly-ordered hexagonal packing of spherical domains were observed. This can be explained by existence of an overlayer of I component formed during the first step dip-coating and subsequent two-dimensional film developping in the second step.