侧链聚硅氧烷液晶的研究进展

介绍了侧链聚硅氧烷液晶的制备、表征、性能影响因素、应用以及前景。     

侧链液晶聚硅氧烷的合成及性能

介绍了带有性侧链液晶基团的聚硅氧烷的合成，系统论述了其链结构，取代度和相对分子质量与液晶相变温度，液晶相态温度范围，液晶态结构等之间的关系。铡链液晶聚硅 显著而稳定的热致液晶性，其液晶相态温度范围可宽至３０７℃，且可获得少见的柱状相液晶，其广角Ｘ射线衍射谱图在０．４３－０．４７ｎｍ和１．９６－３．３１ｎｍ处出现２个特征峰。     

侧链液晶聚硅氧烷的研究进展

侧链液晶聚硅氧烷是一类极具发展前景的新型功能材料,它具有独特的光学、电磁学、黏温特性及较好的机械性能,可用于色谱分离、生物材料、光电信息存贮材料等方面。综述了近年来国内外侧链液晶聚硅氧烷的研究进展,对几种主要类型的侧链液晶聚硅氧烷,即近晶型、向列型、胆甾型以及鱼骨型作了较全面的总结,并对其在色谱分离、生物材料、光电信息存贮材料等方面的应用进行了详细的介绍,最后对其目前的现状作了总结,并对其应用前景进行了展望。     

基于氢键自组装的侧链聚硅氧烷液晶的研究进展

通过与传统的侧链聚硅氧烷液晶的对比,阐述了氢键自组装侧链聚硅氧烷液晶独特的优点;简要介绍了羧基-羧基体系、羧基-吡啶体系、羧基-咪唑体系氢键自组装侧链聚硅氧烷液晶的研究现状,此外,还根据类似的非聚硅氧烷型液晶体系设想了羧基-氨基吡啶体系氢键自组装侧链聚硅氧烷液晶和酚羟基-吡啶体系氢键自组装侧链聚硅氧烷液晶;并概述了液晶常用的表征方法.     

侧链聚硅氧烷液晶弹性体的合成与性能研究

综述了国内侧链聚硅氧烷液晶弹性体的研究情况,并对不同类型的侧链聚硅氧烷液晶弹性体的分子结构、结构与性能之间的关系进行了总结。     

液晶高分子的分子设计

简单介绍了液晶高分子的结构特点，分类及其应用状况，详细介绍了主链型和侧链型液晶高分子设计的新进展，根据溶臻主链型液晶高分子和热臻主链型液晶高分子分子结构的不同，提出今后设计主链液晶高分子的主要任务，从主链结构，液晶基元类型和柔性间隔出发介绍了侧链液晶高分子分子设计的关键，最后介绍了液晶高分子分子设计的发展趋势。     

侧链改性聚硅氧烷的应用研究进展

综述了侧链改性聚硅氧烷在生物医学材料、色谱材料、聚合物催化剂和引发剂、涂层材料、消泡剂、离子萃取剂、聚合物电解液、粘合剂、陶瓷粉体材料、液晶上的应用研究进展,指出了其应用研究前景。     

液晶聚合物的研究进展

综述了近年来液晶聚合物的研究状况和合成技术进展,重点讨论了主链型液晶聚合物、侧链型液晶聚合物及甲壳型液晶聚合物的分子结构设计、合成方法及主要性能。同时对液晶聚合物的发展趋势及应用前景进行了分析和展望。     

主链液晶聚硅（氧）烷的液晶行为

综述了主链液晶聚硅烷和主链液晶聚硅氧烷（包括线型、环型和梯形结构）的热致和溶致液晶行为，指出主链液晶聚硅（氧）烷具有较稳定的热致液性能，其液晶相态温度范围最宽可达３７５℃，且多数在室温下 柱状液晶相态。带有表面活性苈团例链的线型聚硅烷以水为溶剂时，可形成溶致液晶，其呈现液晶行为的临界浓度约为３０％。液晶聚硅（氧）烷所具有的液晶行为膜使其成为一种新型的功能性硅橡胶。     

侧链液晶环氧树脂及其固化物的研究

本文以联苯单酚为介晶基元合成了单官能团环氧树脂，再与双酚A型环氧树脂和二元胺交联聚合制备了侧链型的液晶环氧网络材料，保持了较好的液晶织态。     

新型偶氮类聚硅氧烷液晶的合成及表征

通过对硝基苯胺和苯酚的重氮化反应合成了端基为硝基的刚性基元,再经醚化、加成、酯化反应,合成了偶氮类聚硅氧烷液晶.通过IR、1H NMR对该化合物的结构进行了鉴定,并用POM、DSC对其液晶行为进行了表征.结果表明,该化合物属于近晶A型液晶,相变区间为155.558～226.381℃.     

Guest-host ferroelectric side-chain liquid crystalline polymeric materials with improved electro-optical properties

A ferroelectric side-chain liquid crystalline polysiloxane (FLCP) containing azobenzene dyes as guest molecules for electro-optics has been investigated. The intensity and frequency of the Goldstone mode for the FLCP were increased remarkably after doping with azobenzene dyes. Larger fluctuation of the spontaneous polarization vector in each smectic layer under an applied electric field can be brought about with the addition of a strong dipole-moment guest molecule. This leads to a larger spontaneous polarization and shorter response time. It was found that the doping of a suitable amount of a strong dipole-moment azobenzene dye in the LC phase of the FLCP is helpful for the improvement of the electro-optical properties.     

聚硅氧烷类液晶高分子的研究进展

综述了聚硅氧烷类液晶高分子的最新研究进展,对聚硅氧烷类液晶高分子的各种制备方法和性能进行了总结和评价,对其在液相色谱、光学工程、人工肌肉等方面的应用也作了介绍。     

四苯基乙烯室温液晶发光材料的制备与表征

发光液晶兼具发光性能和液晶的有序性,作为一种具有重要应用前景的功能材料而受到研究人员的广泛关注。本工作采用离子自组装法制备了一种兼具聚集诱导发光和液晶性质的四苯基乙烯衍生物(TPE-Chol)。通过吸收光谱、荧光光谱和X射线衍射等实验对TPE-Chol的光物理性质和液晶结构进行了详细研究。实验结果表明,TPE-Chol在室温状态下具有液晶结构,并且表现出典型的聚集诱导发光行为,是一种新型室温液晶发光材料,在液晶显示等领域具有潜在的应用价值。     

Gel formation and liquid crystalline order in cellulose triacetate solutions

The formation of a liquid crystalline state of cellulose triacetate solution in trifluoroacetic acid was studied using optical microscopy, polarimetry and circular dichroism measurements. Below a critical concentration of $\text{34}\text{g}\text{100}\text{ml}$ a clear isotropic solution was formed. Solutions more concentrated than this were in the cholesteric liquid crystalline state. If water was added to the solution, a gel phase was formed if the polymer concentration was above a critical value. We interpret our observations in terms of the Pincus-de Gennes theory and show that the formation of liquid crystalline order involves both inter-and intramolecular forces.     

香精在液晶乳液和织物柔顺剂中的分配特性

采用固相微萃取和气相色谱的分析技术测定顶空中挥发性物质的浓度随时间的变化,研究了层状液晶乳液体系在应用到织物柔顺剂中时其乳液结构及香精的极性对香精在应用基体中的分配特性的影响。结果发现由聚氧乙烯醚失水山梨糖醇脂肪酸酯、失水山梨糖醇脂肪酸酯、长链脂肪醇、油和水组成的球形层状液晶乳液LO相或者球形层状液晶乳液LO相与平面层状液晶乳液Lβ的混合相能够在应用过程中有效地延缓挥发性物质的释放平衡。具有不同的油相ClogP的液晶乳液,其缓释性也各不相同,含高极性香精的液晶乳液在水溶液中的缓释效果较好。     

Relation between molecular structure and electrorheological effects in liquid crystalline polymers

The influence of the molecular structure of homogeneous fluids comprised of liquid crystalline polysiloxanes (LCSs) diluted in polydimethylsiloxane (DMS), on the increase in their viscosity upon application of an electric field (electrorheological effect, or the ER effect) was investigated, particularly in relation to the degree of polysiloxane polymerization, the composition of their mesogenic side chains, and the composition of alkyl spacers inserted between these two components. A large ER effect was observed in LCSs having spacer length of 3 carbons (C3) and diluted with DMS, even though little such effect was observed with no DMS dilution. The ER effect generally increased with increasing DMS dilution and with increasing mesogenic group content, main chain length, and spacer length. At the same time, however, the miscibility of the DMS solvent with the LC polymer decreased, resulting in instability and difficulty in measuring the shear stress at temperatures up to 40°C or higher. When spacers containing an ether bond were employed, on the other hand, little or no polymer-solvent phase separation occurred, and the ER effect was strong and stable down to temperatures of 30°C or lower. With all of the LCSs, the ER effect was observed at temperatures above their isotropic phase transition temperature as measured by DSC. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 303–310, 1997