Eremin Alexey, Nádasi Hajnalka, Kurochkina Margarita, Haba Osamu, Yonetake Koichiro, Takezoe Hideo
Otto von Guericke University, Institute of Physics , 39016 Magdeburg , Germany.
Department of Organic Materials Science , Yamagata University , 4-3-16 Jonan , Yonezawa , Yamagata 992-8510 , Japan.
Langmuir. 2018 Dec 4;34(48):14519-14527. doi: 10.1021/acs.langmuir.8b02823. Epub 2018 Oct 16.
We report on the structure and optical manipulation of the director configurations in emulsions of liquid-crystalline droplets of a compound exhibiting the nematic (N) and the twist-bend nematic (N) phases. We demonstrate a decrease in the ratio of the bent elastic constant K to the splay constant K by nearly 2 orders of magnitude with decreasing temperature in the N phase. The director structures in liquid-crystal droplets doped with a photoswitchable surfactant without and under ultraviolet (UV) light are discussed in light of the strong elastic anisotropy of the investigated compound. We also compare our findings with the results obtained in doped nematic droplets of a conventional 4-cyano-4'-pentylbiphenyl (5CB) liquid crystal. The dynamics of droplets in the N phase by UV light irradiation are also studied using polarizing and confocal microscopies.
我们报告了一种呈现向列相（N）和扭曲向列相（N）的化合物的液晶液滴乳液中指向矢构型的结构及光学操控。我们证明，在向列相（N）中，随着温度降低，弯曲弹性常数(K)与展曲常数(K)之比下降了近两个数量级。鉴于所研究化合物具有很强的弹性各向异性，我们讨论了未掺杂和掺杂了光开关表面活性剂的液晶液滴在紫外光照射下的指向矢结构。我们还将我们的研究结果与在传统的4-氰基-4'-戊基联苯（5CB）液晶的掺杂向列液滴中获得的结果进行了比较。此外，我们还利用偏光显微镜和共聚焦显微镜研究了紫外光照射下向列相（N）中液滴的动力学。
