含Gemini表面活性剂的PVA分散液晶的微结构与性能  

MICROSTRUCTURE AND PERFORMANCES OF PVA DISPERSED LIQUID CRYSTALS CONTAINING GEMINI SURFACTANT

作　　者：毕曙光[1] 彭海炎[1] 廖永贵[1] 杨亚江[1] Bogumil Brycki 解孝林[1,3] 

机构地区：[1]华中科技大学化学与化工学院、材料化学与服役失效湖北省重点实验室,武汉430074 [2]波兹南密茨凯维奇大学化学系,波兹兰波兰 [3]华中科技大学国家防伪工程技术研究中心,武汉430074

出　　处：《高分子学报》2012年第6期628-632,共5页Acta Polymerica Sinica

基　　金：国家杰出青年基金(基金号50825301);科技部国际合作项目(项目号2009DFA52530)资助

摘　　要：采用N,N'-二(十二烷基)-N,N,N',N',N″-五甲基-1,4,7-三氮杂双碘化氨为Gemini表面活性剂,液晶为4-正戊基-4'-氰基联苯(5CB),通过微胶囊法制备了聚乙烯醇(PVA)分散液晶薄膜,着重研究Gemini表面活性剂对PVA分散液晶薄膜的微结构、电光特性的影响.结果表明,加入Gemini表面活性剂仅略微增加了PVA与5CB液晶的相容性,PVA分散液晶仍保持较高的相分离程度,但是Gemini表面活性剂使液晶微滴尺寸明显变小,液晶相均匀分散地于PVA基体中,液晶指向矢构型由两极型变化为径向型,PVA分散液晶薄膜的对比度和响应速度明显提高,同时保持较低的驱动电压.By means of encapsulation method, poly （vinyl alcohol） （PVA） dispersed liquid crystal films （PDLCs） have been prepared with 4-pentyl-4＇-cyanobiphenyl （5CB） as a liquid crystal （LC） phase and N, N＇-didodecyl-N, N, N＇, N＇, N＂- pentamethyl-1,4,7-triazaheptane diiodide as a Gemini surfaetant. The effects of Gemini surfactant with a concentration slightly larger than its critical mieelle concentration （CMC） on the microstructures and electro-optical properties of PDLCs have also been investigated. The addition of Gemini surfactant slightly enhances the compatibility between PVA and LC. The PDLC films still retain high degree of phase separation,/, e. ,0.85, in comparison with 0.92 for PDLCs without any surfactant. The LC phases are uniformly dispersed in PVA matrix, but the size of LC droplets decreases greatly from 2 - 30 μm without surfaetant to 2 -5 μm with the addition of Gemini surfactant. Moreover, the configuration of LC director changes to be radial from bipolar. Additionally,the addition of Gemini surfactant increases the contrast and the response speed of PDLCs, and retains a low driving voltage of 4.6 V. The transparency under zero voltage, switch-on time and switch-off time are 51.8% ,18 ms and 14.2 ms for the PDLCs without surfactant,10.2% , 1.5 ms and 10.5 ms for the PDLCs with Gemini surfactant,respectively.

关 键 词：聚合物分散液晶 GEMINI表面活性剂 微结构 电光特性 

分 类 号：O753.2[理学—晶体学]