| 초록 |
We investigated thin films of binary mixtures of symmetric diblock copolymers having different molecular weights. In both PS-PMMA and PS-PVP cases, the preferential interaction of block components to substrate and air interfaces caused the mixture to organize into alternating lamellae parallel to the substrate. The morphology of thin films was confirmed by cross-sectional TEM. The lamellar period found in TEM images was increased linearly with the increase of fractions of large molecular weight copolymers, and was scaled with the number-average molecular weight as d ~ Mn0.65in PS-PMMA mixtures and d ~ Mn0.65 in PS-PVP mixtures. Variations of edge slopes in islands/holes on the film surface and in steps formed at the film edge were also carefully studied by AFM. In addition, we observed terraced islands on the film surface in the case of high fractions of large molecular weight copolymers. |
