应用于325 nm波段高透过低降解液晶材料

High transmittance and low degradation liquid crystal materials applied in the 325 nm wavelength range

液晶空间光调制器通过改变驱动电压强度控制液晶分子排布实现对光的调制。紫外区域可用的液晶空间光调制器随光聚合式3D打印等应用的兴起,重要性日益显现。然而绝大多数液晶材料都是有机物,在紫外波段存在光吸收和光反应。为了拓宽液晶材料的应用波段,本文通过选择在应用波段不发生紫外吸收和光反应的官能团,设计了一类可在325~400 nm波段应用不发生光吸收和光反应的液晶材料,并对液晶材料的紫外-可见光光谱进行仿真以验证设计的合理性。将耐紫外液晶化合物配置成混合液晶材料后与常见的两种混合液晶材料的紫外稳定性进行比较。在经过120 min的325 nm紫外光源的辐照后,液晶材料的吸光度和相变温度几乎不变,双折射率变化0.04%,阈值电压变化1.39%,响应时间变化0.32%。

By controlling the arrangement of liquid crystal molecules,liquid crystal spatial light modulators(LC-SLM)modulate light through changing external voltage intensity.Recently,the importance of LC-SLM applicable in ultra-violet region continuously increases due to multiple applications such as photo-polymerization 3D printing.However,the vast majority of liquid crystal materials are organic compounds that absorb light and react in ultraviolet band.To expand the application band of liquid crystal materials,this paper designs a class of liquid crystal materials that do not absorb or react to light in the 325~400 nm band by selecting functional groups that do not absorb or react to light in the application band and simulating the ultraviolet-visible spectrum of the liquid crystal materials to verify the rationality of the design.The ultraviolet stability of the liquid crystal materials is compared with that of two common mixed liquid crystal materials after the ultraviolet-resistant liquid crystal compound is configured into a mixed liquid crystal material.After being irradiated by a 325 nm ultraviolet light source for 120 min,the absorbance and phase transition temperature of the liquid crystal material hardly change,the birefringence changes by 0.04%,the threshold voltage changes by 1.39%,and the response time changes by 0.32%.