Polymer-dispersed liquid crystal nanocomposites comprising montmorillonite clay modified by conducting pentamerous oligoaniline
Polymer-dispersed liquid crystal nanocomposites comprising montmorillonite clay modified by conducting pentamerous oligoaniline
复制标题
DOI：
10.1039/c2jm31379k
复制
发表时间：
2012-06
影响因子：
--
通讯作者：
T. Tsai;Chun-yi Lee;Chen Ju Lee;M. Lin;Wei Lee
中科院分区：
文献类型：
--
作者：
T. Tsai;Chun-yi Lee;Chen Ju Lee;M. Lin;Wei Lee
采用硫酸对五聚苯胺（POA）进行质子化，制备了翠绿亚胺盐（ES），并将其插层到蒙脱土（MMT）CL 120中，制备了功能性导电有机层状材料。通过广角X射线衍射（WAXD）分析改性粘土CL 120/ES-POA的层间距d，通过傅里叶变换红外（FTIR）光谱分析改性粘土CL 120/ES-POA中苯胺齐聚物官能团，并通过高分辨热重分析（TGA）确定改性剂在粘土中的理论插层量。通过离子交换反应成功地将ES-POA插层到蒙脱土中。在特定的情况下，将1wt%的改性粘土负载到49wt%光敏单体和50wt%液晶（NLC）的混合物中，制备了聚合物分散液晶（PDLC）复合材料，从而得到新型的功能性纳米复合材料。CL 120/ES-POA的杂交明显改善了PDLCs的电光性能。在这项工作中，掺杂1wt%的CL 120/ES-POA有利地降低了近70%的驱动电压，将透射对比度提高了五倍，并在25 Vrms下将响应时间从4.6 ms缩短到0.7 ms，但牺牲了视角特性。
Pentamerous oligoaniline (POA) was protonated with sulfuric acid to form emeraldine salts (ES) and then intercalated in montmorillonite (MMT) CL120 to develop a functional conductive organo-layered material. The characteristics of the modified clay CL120/ES-POA were analyzed by wide-angle X-ray diffraction (WAXD) to find the d-spacing of the MMT layer distance, and by Fourier transform infrared (FTIR) spectroscopy for the oligoaniline functional group in CL120/ES-POA, and high-resolution thermogravimetric analysis (TGA) to determine the theoretical intercalation capacity of the modifying agent in the clay. We successfully intercalated the ES-POA into the MMT by ionic exchange reaction. Polymer-dispersed liquid crystal (PDLC) composites were prepared from the modified clay of 1 wt% loaded in the mixtures of 49 wt% photosensitive monomer and 50 wt% nematic liquid crystal (NLC), in a specific case, so as to generate novel functional nanocomposites. The hybridization of CL120/ES-POA clearly improved the electro-optical properties of the PDLCs. In this work, doping CL120/ES-POA at 1 wt% beneficially lowered the driving voltage by almost 70%, increased the transmission contrast ratio by five times and reduced the response time from 4.6 to 0.7 ms at 25 Vrms at the expense of the viewing-angle properties.