Self-Assembly of Polymer Droplets in Nematic Liquid Crystal at Phase Separation
Self-Assembly of Polymer Droplets in Nematic Liquid Crystal at Phase Separation
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相分离向列液晶中聚合物液滴的自组装
DOI：
10.1103/physreve.77.041702
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
M. Ichikawa and Y. Kimura
中科院分区：
文献类型：
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作者：
K. Kita;M. Ichikawa and Y. Kimura
我们研究了聚合物和向列液晶二元混合物在稀释聚合物浓度下的相分离。除了先前报道的直链外，还观察到各种类型的聚合物液滴的规则自组装，如支链和之字形链。自组装的动力学过程主要是由伴随液滴的拓扑缺陷的转变以及液滴的简单生长所决定的。从环缺陷（土星环缺陷）到点缺陷（偶极子缺陷）的自发转变是形成大小相同的液滴直链的必要过程。我们还发现，变形是由附近有点缺陷的液滴引起的。这导致液滴在链簇中的大尺寸分布，从而形成支链。用静电类比讨论了链机制的不同。我们还澄清了组装中的对称性破缺是由包含二元混合物的单元被摩擦的方向决定的。
We have studied the phase separation of a binary mixture of a polymer and a nematic liquid crystal at a dilute polymer concentration. Various types of regular self-assemblies of polymer droplets such as branched chains and zigzag chains have been observed in addition to the previously reported straight chains. The kinetic process of the self-assembly is dominated by the transformations of a topological defect accompanied by a droplet in addition to the simple growth of the droplet. The spontaneous transformation from a ring defect (Saturn-ring defect) to a point defect (dipole) is an essential process in forming a straight chain composed of droplets with the same size. We also find that the transformations are induced by a nearby droplet with a point defect. This leads to a wide size distribution of droplets in a chain cluster and results in a branched chain. The difference in the chaining mechanisms is discussed using an electrostatic analogy. We also clarify that the symmetry breaking in the assembly is governed by the direction in which the cell containing the binary mixture is rubbed.