Matsuyama Akihiko
Department of Bioscience and Bioinformatics, Faculty of Computer Science and Systems Engineering, Kyushu Institute of Technology, Kawazu 680-4, Iizuka, Fukuoka 820-8502, Japan.
J Chem Phys. 2014 Nov 14;141(18):184903. doi: 10.1063/1.4901085.
We present a mean field theory to describe phase behaviors in mixtures of a polymer and a cholesteric liquid crystal under an external magnetic or electric field. Taking into account a chiral coupling between a polymer and a liquid crystal under the external field, we examine twist-untwist phase transitions and phase separations in the mixtures. It is found that a cholesteric-nematic phase transition can be induced by not only the external field but also concentration and temperature. Depending on the strength of the external field, we predict cholesteric-paranematic (Ch+pN), nematic-paranematic (N+pN), cholesteric-nematic (Ch+N) phase separations, etc., on the temperature-concentration plane. We also discuss mixtures of a non-chiral nematic liquid crystal and a chiral dopant.
我们提出一种平均场理论来描述在外部磁场或电场作用下聚合物与胆甾型液晶混合物中的相行为。考虑到外部场作用下聚合物与液晶之间的手性耦合，我们研究了混合物中的扭曲 - 解扭曲相变和相分离。结果发现，胆甾相 - 向列相转变不仅可由外部场引发，还受浓度和温度影响。根据外部场的强度，我们预测了在温度 - 浓度平面上的胆甾相 - 准向列相（Ch + pN）、向列相 - 准向列相（N + pN）、胆甾相 - 向列相（Ch + N）相分离等情况。我们还讨论了非手性向列型液晶与手性掺杂剂的混合物。
