Gelation of liquid crystals with self-assembled fibers.
Gelation of liquid crystals with self-assembled fibers.
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DOI：
10.1007/b107176
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发表时间：
2005
影响因子：
8.6
通讯作者：
Takashi Kato;Norihiro Mizoshita;Masaya Moriyama;Tetsu Kitamura
中科院分区：
文献类型：
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作者：
Takashi Kato;Norihiro Mizoshita;Masaya Moriyama;Tetsu Kitamura
用低分子量凝胶剂对液晶进行物理凝胶化，可以形成一类新型的各向异性凝胶，这些凝胶在光学、电学和光功能材料方面具有很大的潜力。液晶（LC）物理凝胶是由液晶和自组装固体纤维组成的微相分离的各向异性复合材料。对于这些材料，各向同性各向异性转变由于液晶和溶胶-凝胶转变由于胶凝剂可逆地和独立地发生。通过组分的选择和组合来调节LC凝胶的热、光学和电学性质，这决定了微相分离结构。基于室温向列型液晶的LC凝胶显示出扭曲向列型和光散射模式的电光切换。在纤维添加剂的存在下，可以改善电光性能。用作空穴传输材料的分散液晶已被用作各向异性凝胶的LC组分。所述分散凝胶表现出比单独的液晶更高的空穴迁移率。用功能部分对胶凝剂进行化学修饰是LC凝胶功能化的另一种通用方法。已经开发了具有光可切换偶氮苯部分的氢键胶凝剂并与液晶复合。所得的光响应性LC凝胶显示光诱导的结构变化，这是适用于光信息记录。
Physical gelation of liquid crystals with low molecular weight gelators leads to the formation of a new class of anisotropic gels that have great potentials for optical, electrical, and photofunctional materials. The liquid crystalline (LC) physical gels are microphase-separated anisotropic composites consisting of liquid crystals and self-assembled solid fibers. For these materials, the isotropic–anisotropic transitions due to liquid crystals and the sol–gel transitions due to gelators occur reversibly and independently. The thermal, optical, and electrical properties of the LC gels are tuned by the selection and combination of the components, which determine the microphase-separated structures. LC gels based on room temperature nematic liquid crystals show electro-optical switching on twisted nematic and light scattering modes. The electro-optical properties can be improved in the presence of fiber additives. Discotic liquid crystals that function as hole transport materials have been used as LC components of anisotropic gels. The discotic gels exhibit hole mobilities higher than those of the liquid crystal alone. Chemical modification of gelators with functional moieties is another versatile approach for functionalization of LC gels. Hydrogen-bonded gelators with photoswitchable azobenzene moieties have been developed and complexed with liquid crystals. The resultant photoresponsive LC gels show light-induced structural changes, which are applicable to rewritable information recording.