Abstract The thin film morphology of binary blends of triblock copolymers (poly(isoprene - block - styrene - block - (2-vinylpyridine)) ISP after solvent vapor annealing (SVA) was investigated using AFM, GISAXS and TEM. Although bulk samples of binary ISP blends exhibit tetragonal pattern, thin films led either to tetragonal pattern or hexagonal pattern, depending on the annealing time. These transitions were attributed to the formation of non-synchronized wetting layers of I and P, leading to a variation of the inner composition in I and P during SVA. Surprisingly, the hexagonal morphology exhibited centered hexagons of I and surrounding hexagons of P, which is not predicted nor observed for neat block copolymer samples. Although the system must adopt the lowest P/S interface, our results suggest that the effect of chain length with marked difference in the studied blends is playing a major role. Particularly, the presence of long chains of I favors the formation of I domains with bigger size, in order to keep their conformation entropy loss as small as possible.

中文翻译：

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不同链长 ABC 嵌段共聚物二元共混物中四方和六方图案之间的过渡

我们的结果表明，在所研究的混合物中具有显着差异的链长的影响起着主要作用。特别是，I 长链的存在有利于形成更大尺寸的 I 结构域，以保持它们的构象熵损失尽可能小。