侧链液晶弹性体在向列溶剂中三阶段体积相转变。

Three stage-volume phase transitions of a side-chain liquid crystalline elastomer immersed in nematic solvents.

机构信息

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

出版信息

J Chem Phys. 2010 Mar 14;132(10):104903. doi: 10.1063/1.3353611.

DOI:10.1063/1.3353611

PMID:20232986

Abstract

We theoretically study volume phase transitions of a side-chain liquid crystalline elastomer (LCE) immersed in nematic solvents. Six different uniaxial nematic phases (N(1 parallel), N(1 perpendicular), N(2 parallel), N(2 perpendicular), N(3 parallel), and N(3 perpendicular)) are defined by using orientational order parameter S(m) of a side-chain mesogen, S(b) of a backbone chain, and S(0) of a nematic solvent inside the gel. We derive the free energy of a side-chain LCE dissolved in nematic solvents and calculate the swelling behavior of the LCE, the order parameters, and the deformations of the LCE as a function of temperature. We find various phase transitions of the LCE, such as the isotropic (I)-N(1 parallel)-N(3 perpendicular) and the I-N(2 parallel)-N(3 parallel), etc., accompanied by volume phase transitions. These results present new concepts in the structure of a side-chain LCE dispersed in nematic solvent molecules.

摘要

我们从理论上研究了侧链液晶弹性体（LCE）在向列溶剂中的体积相转变。通过使用侧链介晶的取向序参量 S(m)、主链的 S(b)和凝胶内部向列溶剂的 S(0)，定义了六种不同的单轴向列相（N(1 平行)、N(1 垂直)、N(2 平行)、N(2 垂直)、N(3 平行)和 N(3 垂直)）。我们推导出了侧链 LCE 溶解在向列溶剂中的自由能，并计算了 LCE 的溶胀行为、序参量和 LCE 的变形作为温度的函数。我们发现了 LCE 的各种相转变，例如各向同性（I）-N(1 平行)-N(3 垂直)和 I-N(2 平行)-N(3 平行)等，伴随着体积相转变。这些结果提出了在侧链 LCE 分散在向列溶剂分子中的结构中的新概念。