分子间自组装盘状液晶材料研究进展

综述了近十年来国内外报道的分子间自组装盘状液晶的研究进展;重点阐述了通过分子间氢键或金属离子配位键自组装的盘状液晶小分子和超分子液晶的液晶性能、掺杂了无机纳米粒子的通过氢键形成的液晶材料的光电性能及其在有机光伏器件中的应用;最后总结了不同类分子间自组装盘状液晶的性能优势。综合文献报道可知,引入分子间氢键或配位键可以更好地实现盘状液晶在特定功能材料中的应用,并且自组装的盘状液晶还可与纳米粒子形成复合物,得到具有特定功能的纳米复合材料。     

A Brief Review of Carbazole-Based Photorefractive Liquid Crystalline Materials

Liquid crystals are commonplace in technological devices, such as watch and computer displays and temperature and pressure monitors. Such materials are central to our technological lifestyles. Classically, liquid crystalline materials are based on a structural motif which could be classed as rod-like (e.g. biphenyl derivatives) and in more recent times as disc-like (e.g. triphenylene derivatives). The rod-like materials are very attractive in terms of their chemical stability and their response to electric fields, both of which are a prerequisite for display devices, whereas disc-like materials show promise as one-dimensional conducting materials. Increasing scientific and technological requirements mean that new materials are continually sought to surpass the liquid crystalline materials which are presently known. Carbazole derivatives are well-known interesting natural products. Several methods have been developed and reported in the literature for the synthesis of carbazole derivatives. There are several review articles published on the photorefractive properties of carbazole-based materials. Chemical modification of the carbazole moiety to create a new class of discotic, calamitic and banana-shaped liquid crystalline materials, which will have novel and enhanced photorefractive properties over the amorphous carbazole derivatives, will be discussed in this mini review.     

黏土及类黏土液晶材料的研究进展

黏土矿物(clay minerals)是组成黏土岩和土壤的主要矿物,它是一种含镁、铝为主的水合硅酸盐矿物.研究发现黏土矿物液晶与有机液晶材料相比,具有光、电、磁性能强,热稳定性好,价格低廉等优点.简要介绍了黏土矿物液晶材料的形成机理,概述了片层状黏土液晶材料、纤维型黏土液晶材料、类黏土矿物液晶材料的制备方法和研究现状,同时介绍了不同条件(浓度、离子强度、外电场作用、分散介质、重力作用)对黏土及类黏土分散体系相变的影响,并对黏土矿物液晶材料的应用发展前景进行了概述.     

液晶高分子及其应用

液晶高分子是一类较新的高分子材料,是一类大规模研究工作起步较晚的液晶材料,但由于其本身无与伦比的优点,以及与信息技术、新材料和生命科学相互促进作用,已成为世纪之交的热点之一。简要介绍了液晶高分子聚合物的类型、特性、主要应用以及液晶高分子设计的前景。     

Effect of polymer concentration on polarization switching in polysiloxane‐dispersed ferroelectric liquid crystals

Ferroelectric liquid crystal–polysiloxane composite films were prepared after dissolving them in diethyl ether as a solvent. The crosslinking was done by adding room temperature vulcanizer (mixture of tetra ethoxy silane and dibutyl tin dilaurate) as curing agent. These composite films show good electro‐optic properties with switching times on the order of few milliseconds. The preliminary results show that these systems can be useful as functional materials in electronic displays. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1209–1215, 2003     

溶致液晶模板法制备CuO纳米粒子

利用溶致液晶的有序结构特性,在不同的介观空间内组装不同性质的纳米粒子,从而获得具有特定功能的纳米材料。本文研究内容主要包括：利用非离子表面活性剂Brij58制备反六角相溶致液晶,以该反六角液晶为模板,以Cu（NO3）2水溶液代替体系中的水相制备铜纳米粒子。利用偏光显微镜、X射线衍射和粒度分析仪对样品进行表征。实验表明,不同浓度下形成不同相的液晶,在400℃下煅烧可得到CuO纳米材料。     

苯并菲类高分子液晶材料的研究进展

苯并菲类衍生物因其优异的柱状相液晶性质和良好的自组装能力,被广泛应用于光电材料,并得到有机合成和光电材料工作者的广泛关注和深入探究。作为苯并菲类衍生物的一个重要分支,高分子液晶材料受到了越来越多的关注。简单介绍了苯并菲类高分子液晶的分类、性质以及各类高分子结构对其液晶性质的影响,对苯并菲类液晶高分子材料的发展历程做简单的综述。     

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。     

五种新型高分子液晶研究进展及应用前景

阐述了高分子液晶的形成条件,综述了纤维素液晶、甲壳素液晶、铁电液晶、盘状液晶、卤代液晶等五种新型高分子液晶材料的结构、性能及其应用前景,并对高分子液晶的发展方向进行了展望。     

Studies on electro‐optical properties of polymer matrix/LC/SiO2 nanoparticles composites

Polymer‐dispersed liquid crystal (PDLC) films were prepared by ultraviolet light‐induced polymerization of photopolymerizable monomers in nematic liquid crystal (LC)/monomers/SiO₂ nanoparticles composites, and the effect of SiO₂ nanoparticles on the electro‐optical properties of PDLC films was studied. The observed effect showed that by the adjustment of the SiO₂ nanoparticles content, the refractive index ratio of the LC and polymer could be modulated, and the electro‐optical properties of the polymer matrix/LC/SiO₂ nanoparticles composites could be optimized. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis and properties of vinylic copolymers with fluorescent moieties as optical brighteners for liquid crystals

The synthesis and characterization of new side‐group copolymers of styrene or methylmethacrylate with fluorescent 1,8‐naphthalimide derivatives are described. Basic photophysical characteristics of produced low molar and polymeric fluorescent brighteners are reported. The utility of the brighteners in liquid crystalline displays of the guest‐host type is discussed on the basis of their spectral properties and their effect on the behavior of nematic liquid crystal ZLI 1840 (Merck, Darmstadt, Germany) at phase transition. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 151–157, 1999     

苯并菲类液晶高分子合成及应用

苯并菲类材料能够组装为柱状相,因此在光电材料、信息存储以及功能分子膜中得以广泛应用。主要是探讨苯并菲类液晶高分子合成及应用,希望能够对相关人员起到参考性价值。     

Dielectric and Electro-Optical Properties of Antiferroelectric Liquid Crystalline Materials

Antiferroelectric liquid crystals (AFLCs) are a recent class of materials in the family of liquid crystals which have high prospect of application in displays with better results as compared to conventional nematic displays. Beside technological applications, AFLCs are very interesting from the point of view of basic studies in soft condensed matter systems as these materials are showing various new sub-phases, viz. SmC_α^*, SmC_β^*, SmC_γ^* and many others with distinct macroscopic properties in a narrow temperature region in addition to the most common wide-range low-temperature SmC_a^* phase. In the present article, we report the structure of various sub-phases of AFLCs, their dielectric behaviour and the electro-optical response of some of the materials studied by our group.     

Liquid Crystalline Inorganic Nanosheet Colloids Derived From Layered Materials

Inorganic layered crystals such as clay minerals, layered niobates, and graphite are exfoliated in solvents to form colloidal dispersions of extremely thin inorganic nanosheets. Recently, the liquid crystal phases of these “nanosheet colloids” have been rediscovered and are attracting interest as new types of inorganic liquid crystals. The huge anisotropy of the mesogenic nanosheets compared to other liquid crystal systems is an important feature of the nanosheet liquid crystals for fundamental studies in the fields of colloid science and soft matter physics. In addition, the rich functionalities intrinsic to inorganic materials open a variety of applications such as smart colloids and composite materials with structural regularity. In this article, the recent progress of the emerging new materials of inorganic nanosheet liquid crystals is reviewed with a focus on the behaviors of each system, alignment by external field, and theoretical aspects.     

The Influence of Disorder on Thermotropic Nematic Liquid Crystals Phase Behavior

We review the theoretical research on the influence of disorder on structure and phase behavior of condensed matter system exhibiting continuous symmetry breaking focusing on liquid crystal phase transitions. We discuss the main properties of liquid crystals as adequate systems in which several open questions with respect to the impact of disorder on universal phase and structural behavior could be explored. Main advantages of liquid crystalline materials and different experimental realizations of random field-type disorder imposed on liquid crystal phases are described.     

热致液晶聚酯—热塑性塑料合金的性能和应用前景

热致液晶聚酯(TLCP)—热塑性塑料(TP)合金是近年开发的新型高性能材料之一。本文介绍了该类合金的流变性能、加工特点、以及组成、温度、剪切速率、拉伸比、加工方式等对力学性能的影响。指出,该合金从性能和成本两方面看,是一种具有良好应用前景的新型高性能材料。     

Porosity reduction of polyethylene glycol phase change materials by using nanoscale thermal‐energy‐conducting medium during crystallization process

Poly(ethylene glycols) (PEGs) are phase change materials (PCMs) that exhibit undesirable heat transfer properties, which restrict their industrial utility. Apart from the intrinsic material properties, a large quantity of micropores in the crystalline PEG polymers cause poor heat transfer performance. In this work, the formation and growth of micropores are reported through in situ characterization. The addition of a nanoscale thermal‐energy‐conducting medium into PCMs has been proposed for reducing their porosity. The mechanism for reducing porosity is reported for prepared composite PCMs. The intrinsic causes are thought to be the following. Metal oxide nanoparticles can migrate with the liquid PEG flow, which can reduce the thermal stresses in the crystal growth process. In addition, the nanoscale medium promotes heterogeneous nucleation. The results of this study show that reducing the porosity of the polymer crystals is an important approach for improving the heat transfer properties of the PEG PCMs. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45446.     

溶致液晶模板法制备纳米材料研究进展

主要综述了复合溶致液晶模板和真溶致液晶模板对于纳米材料结构的调控作用。首先讨论了不同复合溶致液晶体系制备介孔材料的方法,并总结了研究介孔材料形貌变化的最新理论成果;而对于真溶致液晶模板,则重点阐述了其对纳米颗粒、纳米棒、纳米线、纳米管和介孔材料的调控作用;最后展望了液晶模板法制备纳米材料的发展趋势。     

液晶显示上游材料中国专利分析

通过对中国发明专利进行数据挖掘和专利计量分析,总结了中国液晶显示上游产业发展趋势和整体情况,分析结果表明中国的液晶产业具有良好的发展前景,少数几个国家拥有大部分的中国专利,企业申请了大量的专利。研究了重点专利持有企业在液晶介质、液晶取向材料、光增亮膜用材料三个技术领域的专利布局 情况。     

含氟盘状液晶研究进展

近年来，在分子中引入氟原子进行改性成为材料研究的热点之一。分子中引入氟原子后，可以影响其热性能、电荷输运性能以及液晶的相行为等，最终改善材料的热、光、电和磁等性质。含氟盘状液晶由于具有较高的载流子迁移率，其合成方法和性质得到了广泛的关注。在含氟盘状液晶分子的平面核上、外围侧链或桥体上取代的氟原子均能显著改变液晶的相变性质，如提升液晶相的热稳定性和柱状相的有序度等。该文综述了近十年来具有代表性的利用氟原子改性盘状液晶的研究进展，进一步证实了氟化有利于改善液晶性质，并进一步归纳了含氟盘状分子在其他领域的应用。盘状液晶氟化后所表现出的优异性能，有助于启发科研工作者在药物合成、无机材料等领域引入含氟材料。