液晶SmC■相的螺距与手征中心分布

THE PITCH AND CHIRAL CENTER DISTRIBUTION IN SmC * LIQUID CRYSTALS

选用双轴性并含有多个手征中心的分子作用势，引入手征中心分布结构因子ζχ，采用格胞模型，求得液晶ＳｍＣ相的螺距表达式和螺旋性反转条件．计算了ＴＤＯＢＡＭＢＣＣ，ＦＬＣ，ＰＡＣＭＢ和Ｈ６／１０等４种典型ＳｍＣ相液晶的螺距随温度的变化及其受ζχ的影响．结果与实验相符．

Abstract  An expression concerning the variation of the pitch of SmC * liquid crystals is obtained by using the cell model in statistical mechanics with the introduction of the distribution factor ζ χ of the chiral centers in the interaction potential between biaxial molecules containing multiple chiral centers.It shows the condition for inversion of helicity of the liquid crystals.With proper choice of the values of parameters involved we have calculated the variation of the pitch with temperature for liquid crystals TDOBAMCC,FLC,PACMB and H6/10.The calculated results agree well with the experimental data. 