Self-assembled phases of block copolymer blend thin films.
Self-assembled phases of block copolymer blend thin films.
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DOI：
10.1021/nn504977r
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发表时间：
2014-10
期刊：
影响因子：
17.1
通讯作者：
K. Yager;E. Lai;C. Black
中科院分区：
文献类型：
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作者：
K. Yager;E. Lai;C. Black
聚苯乙烯-b-聚甲基丙烯酸甲酯嵌段共聚物自组装薄膜形成的模式既可以是空间均匀的单一纳米结构，也可以是分离的、柱状和片状共存的区域，这取决于共混组分的分数组成和分子量比。在具有不同分子量的嵌段共聚物共混物中，较小分子量组分的形态更强烈地决定了所得到的图案。虽然分子尺度链的混合会使纯组分的微畴特征长度尺度发生扭曲，但即使共存的形态也表现出相同的畴间距。我们使用平衡链扭曲能量和混合熵的物理热力学模型，定量地解释了柱状和片状薄膜混合物的相行为。
The patterns formed by self-assembled thin films of blended cylindrical and lamellar polystyrene-b-poly(methyl methacrylate) block copolymers can be either a spatially uniform, single type of nanostructure or separate, coexisting regions of cylinders and lamellae, depending on fractional composition and molecular weight ratio of the blend constituents. In blends of block copolymers with different molecular weights, the morphology of the smaller molecular weight component more strongly dictates the resulting pattern. Although molecular scale chain mixing distorts microdomain characteristic length scales from those of the pure components, even coexisting morphologies exhibit the same domain spacing. We quantitatively account for the phase behavior of thin-film blends of cylinders and lamellae using a physical, thermodynamic model balancing the energy of chain distortions with the entropy of mixing.