Stringlike structure formed in thin films of a lamella-forming diblock copolymer.
Thin films of a lamella-forming polystyrene-block-poly(2-vinylpyridine) diblock copolymer, PS-P2VP, were annealed by a tetrahydrofuran (THF) vapor treatment. The thin films immediately developed a multilayered lamellar structure, similar to those known for conventional heat treatment. However, in the case of the vapor treatment, the steps moved over a significantly larger distance than the case of the heat treatment. This process strikingly developed stringlike objects (strings) that appeared near the steps. The strings were found to be cylindrical domains of poly(2-vinylpyridine) blocks (P2VP) partitioned from P2VP lamella during the step motion and sandwiched by the polystyrene phase that results in perforating the P2VP lamella. The string formation seemed to be associated with the motion of the step, which was considerably faster in the vapor treatment process than in the heat treatment process.
Fukunaga
Kenji
K
UBE Industries, Ltd. 8-1 Goi-minamikaigan, Ichihara, Chiba 290-0045, Japan. 28658u@ube-ind.co.jp
Hashimoto
Takeji
T