向列液晶预倾角与其弹性常量的相关性研究

向列液晶分子在基片上形成预倾角是液晶分子进行重新排列取向的过程,预倾角的大小会影响与取向相关的向列液晶的弹性变形行为.本文通过设置不同的预倾角,在不同的温度下用激光散射技术测量向列液晶的弛豫系数,从而获得液晶的弹性常量,并研究弹性常量随预倾角的变化规律.研究结果表明,当预倾角小于某一角度,由于向列液晶分子内部排列不规整而无法体现其整体的弹性变形特征;当预倾角达到一定的角度,向列液晶就表现出最大的弹性常量值,液晶特有的弹性变形行为得以充分的体现.

Study on the Relativity of Pretilt Angle of Nematic with the Elastic Constants

Nematic molecules produce pretilt angles on the orientation layer is a course of reorientation and rearrangement. The pretilt angles of nematic would affect the actions of elastic distortion. In this paper, the relaxation coefficient of E7 is measured by light laser scattering in different pretilt angles and temperatures and then the elastic constants of E7 is obtained. The change rule of the elastic constants with pretilt angles is studied. The results indicate that when the pretilt angle is less than some one, nematics cannot embody their characteristics of elastic distortion because of disorder arrangement of liquid crystal molecules, when the pretilt angle reaches certain one, nematics obtain the largest elastic constants, and characteristics of elastic distortion of nematics can embody adequately.