Nano-silica enhanced liquid-crystalline composite gels

被引：0
|
作者：
Li Q. [1 ]
Bi S. [1 ]
Zhao D. [1 ]
Liao Y. [1 ,2 ]
Xie X. [1 ,2 ]
机构：
[1] Key Laboratory of Material Chemistry for Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan
[2] National Anti-counterfeit Engineering Research Center, Huazhong University of Science and Technology, Wuhan
来源：
Kexue Tongbao/Chin. Sc. Bull. | / 19卷 / 2155-2162期
关键词：
Electro-optical properties; Liquid crystalline gel; Nano-silica; Self-supporting ability;
D O I：
10.1360/N972016-00004
中图分类号：
学科分类号：
摘要：
Soft micro-environment is one of the most important requirements for fast responses of liquid crystals (LCs) to external stimuli; however, the drawback of poor mechanical properties for LCs limits their further applications. In this work, the storage modulus (G') of the LC physical gels, nematic 4-pentyl-4'-cyanobiphenyl (5CB) and 1,3:2,4-di-O-benzylidene- D-sorbitol (DBS), has been greatly enhanced by the addition of nano-silica into physical gels. The composite gels are formed through the synergistic effects of the nanoparticle and the gelator. The phase transition behaviors, morphologies, dynamic rheological behaviors and electro-optical properties of the composite gels were investigated using differential scanning calorimeter, polarized optical microscope and field emission scanning electron microscope, rheometer and LCD parameter tester, respectively. Compared with the LC physical gel without nano-silica, with the increase of nano-silica content from 0.1wt% to 4.0wt% at a fixed DBS content of 2.0wt%, the network texture of composite gels was changed from nano-fibrillar to spherulite-like. The G' increased firstly and then decreased with a maximum value of 1.5×105 Pa at the nano-silica content of 2.0wt%. The threshold voltage (Vth) and the off time (τoff) increased within 1 time and 2 times, respectively. When the amount of nano-silica was only 0.5wt%, the G' of the composite gel was improved to 105 Pa, an order of magnitude higher than the gel without nanoparticles. Meanwhile, its Vth and τoff only increased 46% and 63%, respectively. This work opens a new window to the applications of LCs with excellent self-supporting ability and fast switch responses. © 2016, Science Press. All right reserved.
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页码：2155 / 2162
页数：7
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