| 초록 |
Hexagonally perforated lamellar (HPL) phase appears at a narrow composition range of block copolymers between the lamellar and hexagonal cylinder phase. It is generally accepted that the HPL phase is meta-stable and HPL ↔ double gyroid (DG) phase transition is irreversible. In this study, we investigated the phase behavior of polystyrene-block-polyisoprene block copolymers at the thin film state. In thin films, layered structures are well-aligned parallel to the substrate plane. Consequently, we were able to obtain large grain morphology of the HPL phase and other phases epitaxially transformed from the HPL phase. In addition, upon quenching from the disordered state, we observed that HPL phase formed first and fully developed before the final conversion to the stable phase such as DG. It indicates that HPL phase could be a kinetically favored state despite its meta-stabiltiy in thermodynamic sense. |
