A practical guide to versatile photoalignment of azobenzenes
A practical guide to versatile photoalignment of azobenzenes
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DOI：
10.1080/02678292.2020.1825842
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发表时间：
2020-10-26
期刊：
影响因子：
2.2
通讯作者：
Zappe, Hans
中科院分区：
文献类型：
--
作者：
Folwill, Yannick;Zeitouny, Zouheir;Zappe, Hans
光对准是指一种用光定义液晶取向的技术。这种方法的基础是使用吸收或触发化学反应的材料，其各向异性取决于光的偏振。偶氮苯在研究应用中是一种公认的液晶排列方法。尽管它们很受欢迎，但公开的过程细节很少。我们在这里考虑使用二色性染料灿烂黄的光对准过程的优化。研究了其在不同溶剂中的溶解度；定向度随曝光时间和强度的变化；不同阶段湿度的影响；以及在环境光存在下过程的稳定性。此外，还对二色性染料刚果红和大黄酚进行了测试，以增加可用光取向材料的组合。
Photoalignment refers to a technique for the definition of the orientation of liquid crystals using light. The approach is based on the use of materials that either absorb or trigger a chemical reaction with an anisotropy that depends on the polarisation of light. Azobenzenes are a well-established for aligning liquid crystals in research applications. Despite their popularity, only few details of the process are publicly available. We consider here the optimisation of the photoalignment process using the dichroic dye Brilliant Yellow. Its solubility in various solvents; the alignment quality as a function of exposure time and intensity; the influence of humidity at various stages; and the stability of the process in the presence of environmental light are investigated. Additionally, the dichroic dyes Congo Red and Chrysophenine are tested to increase the portfolio of available photoalignment materials.