一种新型偶氮染料在扭曲向列相液晶显示取向中的应用

研究了一种新型偶氮材料sy03在光控取向中的应用。将sy03加入聚酰亚胺SE-3310(Nissan)与N,N-二甲基甲酰胺(DMF)的混合溶液中作为90°扭曲向列相液晶显示(Twisted nematic liquid crystal display,TN-LCD)的光取向材料,测量由它作为取向膜的扭曲向列型盒的电光特性与仅用SE-3310取向的扭曲向列型盒电光特性比较,发现sy03偶氮的加入使得扭曲向列型盒的响应时间短到98 ms、阈值电压也降低到1.7 V左右。而且随曝光时间的增加,响应时间和衬比度都有所提高,电光响应曲线也更为陡峭。加热到150℃后,其电光特性并没有明显变化,证明了它良好的热稳定性。最后通过测量偏振紫外吸收光谱,分析得出液晶分子易取向方向与激发光源偏振方向垂直。

Application of New Azo-Dye in the Photoalignmet of Twisted Nematic Liquid Crystal Display

A new azo-dye sy03 is introduced as photoalignment material of twist nematic liquid crystal (TN-LCD). sy03 is added into the mixture composed of polyimide SE-3310 and N,N-dimethylformamide for photoalingment of 90° TN-LCD. And the electro-optic perfermance of the cell aligned by it is measured, and then compared with that of the cell photoaligned with PI SE-3310 only. Apparently, the former is better than the latter for shorter raction time and lower threshold voltage with 98 ms reaction time and 1.7 V threshold voltage. Stability and contrast are improved, and the electrooptic response curve is sharper. After the cell is heated to 150 ℃, obvious change for its electro-optic performance does not occur, which proves its favorable thermal stability. By measuring the polarized UV absorption spectra, it is proved that the easy direction of liquid crystal director is perpendicular to the polarization direction of irradiation ultraviolet light.