新型侧链液晶聚合物的双轴向向列相。

Novel biaxial nematic phases of side-chain liquid crystalline polymers.

机构信息

Department of Bioscience and Bioinformatics, Faculty of Computer Science and Systems Engineering, Kyushu Institute of Technology, Kawazu 680-4, Iizuka, Fukuoka 820-8502, Japan.

出版信息

J Chem Phys. 2012 Dec 14;137(22):224906. doi: 10.1063/1.4771592.

DOI:10.1063/1.4771592

PMID:23249031

Abstract

We present a mean field theory to describe biaxial nematic phases of side-chain liquid crystalline polymers, in which rigid side-chains (mesogens) and rigid-backbone chains favor mutually perpendicular orientations. Taking into account both excluded volume and attractive interactions between rigid rods, novel biaxial nematic phases are theoretically predicted. We calculate uniaxial and biaxial orientational order parameters as a function of temperature and the length of backbone chains. We find a first-order biaxial-biaxial phase transition and a first (or second)-order uniaxial-biaxial one, depending on the length of mesogens and backbone chains.

摘要

我们提出了一个平均场理论来描述侧链液晶聚合物的双轴向列相，其中刚性侧链（介晶基元）和刚性主链倾向于相互垂直的取向。考虑到刚性棒之间的排斥体积和吸引力相互作用，理论上预测了新的双轴向列相。我们计算了单轴和双轴取向有序参数作为温度和主链长度的函数。我们发现存在一级双轴-双轴相转变和一级（或二级）单轴-双轴相转变，这取决于介晶基元和主链的长度。