Ju Changha, Park Chanhyuk, Kim Taehyung, Kang Hyo
Department of Chemical Engineering, Dong-A University 37 Nakdong-Daero 550 beon-gil, Saha-gu Busan 49315 Republic of Korea
RSC Adv. 2019 May 8;9(25):14188-14193. doi: 10.1039/c9ra02629k. eCollection 2019 May 7.
To investigate the alignment behavior of liquid crystal (LC) molecules, we synthesized a series of vanillin derivative-substituted polystyrene films (PVAN#, # = 20, 40, 60, 80, and 100), where # is the substitution ratio (%) of the vanillyl butyl ether (VAN) moiety as one of the bio-renewable vanillin derivatives. In general, a vertical LC alignment was observed in the LC cell fabricated using the polymer film having a higher molar content of VAN. Moreover, the surface energies of these polymer films were strongly related to the vertical LC alignment behavior. For example, a uniform vertical alignment was observed when the polar surface energy of the polymer was lower than approximately 2.05 mJ m, induced by the nonpolar and long carbon groups in the plant-based vanillin moiety. The LC cell fabricated using PVAN100 had good electrooptical characteristics such as voltage holding ratio and residual direct-current voltage and stable alignment under extreme external conditions.
为了研究液晶（LC）分子的排列行为，我们合成了一系列香草醛衍生物取代的聚苯乙烯薄膜（PVAN#，# = 20、40、60、80和100），其中#是作为生物可再生香草醛衍生物之一的香草基丁醚（VAN）部分的取代率（%）。一般来说，在使用具有较高摩尔含量VAN的聚合物薄膜制备的LC盒中观察到垂直的LC排列。此外，这些聚合物薄膜的表面能与垂直LC排列行为密切相关。例如，当聚合物的极性表面能低于约2.05 mJ/m²时，观察到均匀的垂直排列，这是由植物基香草醛部分中的非极性长碳基团引起的。使用PVAN100制备的LC盒具有良好的电光特性，如电压保持率和残余直流电压，并且在极端外部条件下排列稳定。
