空间各向异性色散两体势向列相液晶形变研究

Study of Distortions in Nematic Liquid Crystal Based upon the Dispersion Force Pair Potential with Spatial Anisotropy

基于空间各向异性色散力势能,用简单的立方格子模型研究具有n层液晶分子所组成的向列相液晶形变。理论处理中假定具有理想向列序,这意味着分子长轴取向方向与液晶指向矢是一致的,而总自由能等于相互作用能。文中以解析形式研究了三种基本的Fredericksz转变,给出了三个弹性常数,在近似下它们是相同的,且与连续体理论比较可以得到k13。

Distortions in a nematic liquid crystal composed of n molecular layers is investigated using a simple cubic lattice model, based upon the dispersion force pair potential with spatial anisotropy. The perfect nematic order is assumed in the theoretical treatment, which means the orientation of the molecular long axis coincides with the director of liquid crystal and the total free energy equals to the total interaction energy. Three kinds of the basic Fredericksz transition are investigated analytically. We give the three elastic constants, in terms of the potential parameters, they are same in our approximation, and get the by compared with the continuum theory.