单臂液晶冠醚LB膜的研究

首次研究了４种单液晶冠醚（１～４）的ＬＢ膜成膜特性，实验发现它们在气－液界面均可形成单分子膜，但４的稳定性较差，３易转移到玻璃基片上形成Ｙ型膜。４种化合物与硬脂酸以１：１混合形成稳定的Ｙ型ＬＢ膜。小角Ｘ射线衍射证实了膜的有序结构。用ＣＰＫ原子模型对成膜分子构型和面积进行了估算，其结果与实验一致。并讨论了分子结构对成膜性能的影响。     

液晶冠醚LB膜的制备及其性质研究

本文首次研究了五种新合成的液晶冠醚ＬＢ膜的成膜特性。实验发现，其中的单臂胆甾型液晶冠醚在气－液界面易形成稳定的单分子膜，但不易累积形成ＬＢ膜；芳香酯类的单臂液晶冠醚膜的稳定性与链的长短有关；而双臂芳香酯型二氮杂１８－冠－６易形成稳定的膜，且具有特殊的相变性质。膜的特性与物质的化学结构有关，借助ＣＰＫ分子模型，对成膜后分子构型进行了估算，理论计算与实验一致。对纯组分以及单臂液晶冠醚与硬脂酸的混合膜结构，用表面压－面积曲线以及小角Ｘ衍射等进行了表征，并对其中的双臂液晶冠醚作了离子识别功能研究。     

含液晶基团的冠醚LB膜研究

合成了含有联苯介晶基团的长链冠醚,并首次制成含液晶基团的冠醚LB膜,由LB膜的荧光光谱研究发现,与其单体在CHCl_3稀溶液中的荧光光谱相比,LB膜的荧光光谱向长波方向移动,表明分子均以缔结状态存在,XRD结果表明,LB膜具有良好的有序结构,单分子膜厚2.6nm。     

液晶聚合物的单层与Langmuir-Blodgett膜

系统研究了手性液晶聚硅氧烷和光致变色液晶聚硅氧烷两个毓的侧链液晶聚合物在空气/水界面的单层行为和Langmuir-Blodgett(LB)膜沉积特性,对LB膜结构与存在的聚集现象进行了系统的表征,并初步探讨了LB膜中液晶聚合物表现的功能性。     

冠醚和卟啉与花生酸混合单分子膜行为研究

本文将3'-正十五烷基苯并15-冠-5和六种无脂链难于直接成膜的四苯基卟啉与花生酸混合形成单分子膜。结果表明, 冠醚被嵌进而卟啉被挤出花生酸单分子层。卟啉-花生镉LB膜的可见吸收光谱指出卟啉分子成团聚集。扫描电镜观察了卟啉-花生酸镉混合LB膜的表面形貌, 在膜表面上无金涂层时直接测到了混合膜的相分离。     

单臂冠醚结构与液晶性质

设计并合成了4个单臂冠醚液晶,考察了冠醚环与亲酯性结构单元之间的桥键与液晶性质的关系,中心桥键对单臂冠醚液晶的熔点影响不大,而对液晶热稳定性有较大的影响.     

镶嵌血卟啉的硬脂酸LB膜研究

制备了嵌有血卟啉的硬脂酸LB膜, 结果表明, 血卟啉分子镶嵌在硬脂酸间分子膜内, 在混合LB膜中血卟啉分子之间未发生强的相互作用, 其大环平面为倾斜取向。     

单臂冠醚的结构与液晶性质

设计并合成了３个低温冠醚液晶－单臂脂环冠醚液晶，考察了冠醚结构与液晶性质的关系，单臂冠醚液晶分子具有液晶蛋白质应满足长径比大于３，分子具有一定的平面特性和能通过引入手性基团使单臂冠醚液晶分子产生手性近晶相等条件。     

具有不同取代链长的卟啉衍生物LB膜的结构研究

本文研究了三种羧酸取代的四苯基卟啉衍生物在空气/Cd^2^+水溶液界面上所形成的单层膜及LB膜。这三种卟啉衍生物中, 一种没有脂链, 另外两种具有不同长度的脂链。由π-A等温线得到的平均表观分子面积相差很大。紫外-可见光谱表明, LB膜中卟啉的Soret吸收带相对于溶液的吸收均红移, 但红移程度不同。LB膜的偏振紫外-可见光谱表明, LB膜中三种卟啉衍生物的卟啉环具有基本一致的取向。运用亚相降低法得到了三种卟啉衍生物单层LB膜, 其紫外-可见光谱与用垂直提拉法得到的LB膜的紫外-可见光谱具有一致的特征。这些结果表明: 卟啉衍生物有无取代链及取代链长的不同对平均表观分子面积的大小和膜中环间的距离有影响, 但对环的取向没有影响。环的取向由环本身及环上的亲水取代基来确定。气/液界面上三种卟啉衍生物的单层膜中环也具有一致的取向, 且与LB膜中环的取向相差不大。提拉不会对膜中环的取向及膜的结构造成大的改变。     

侧链液晶聚硅氧烷langmuir膜的原子力显微镜观察

通过原子力显微镜观测了含手性基团侧链液晶聚硅氧烷在空气/水界面上的单层膜,观测了成膜物在界面形成微畴结构以及表面压力升高时微畴聚集、重排过程,分析了纳米级微畴形成、聚集和重排的机理和规律。     

Use of a long-spacer-side-chain liquid crystalline polysiloxane containing a crown ether as a stationary phase for capillary gas chromatography

A new kind of side chain liquid crystalline polysiloxane containing a crown ether with a longer spacer (PSC-11) has been prepared and coated on a fused silica capillary column. The main chroma-tographic characteristics including efficiency, polarity, and selectivity have been examined. The phase exhibits the retention properties of both liquid crystal and crown ether stationary phases and possesses higher efficiency and better selectivity than PSC-3, which has a shorter spacer between the main polysiloxane chain and liquid crystalline side chain.     

The Mixed LB film of Crowned Phthalocyanine and Picrate

Phthalocyaninesareexcellentpigmentswithgo0dthermalandchemicalstability.TheypossessanumberofcharacteristicsthatmakethemsuitableforaPplicahonsinthefieldofmolecularelectronicsl.LBfilmsofphtalocyanineshavebeenwidelystudiedinthepastdecades2'3.PreviouslywereportedthefabricationofmixedLBfilmsofanamphiphilicphthalocyanineandhydrophobicporphyrin4.Herewereportthedepositionandcharacterizationofthemixedfilm0fphthalcyaninehavingapendantcr0wnethergroupandnacceptor(picrate)basedonhost-guestcomPlexation.Mo…     

From crown ethers to zeolites: Reaction of EtAlCl2 with crown ethers

In contrast to aluminum alkyls, alkyl aluminum halides such as EtAlCl₂ react with crown ethers to form cation-anion pairs which exhibit the liquid clathrate effect. Specifically, [12-C-4·AlCl₂][AlCl₃Et] and [18-C-6·AlCl₂][AlCl₃Et] have been isolated and characterized by X-ray diffraction techniques. The cations show aluminum in an octahedral environment made up of four of the oxygen atoms from the crown and two chlorine atoms. The 12-C-4 derivative crystallizes in the monoclinic space group P2₁/c with cell constants of a=7.497(4), b=22.121(8), c=12.339(5) Å, =94.99(3)^o, and Z=4 for =1.43 g cm^–3. Least-squares refinement based on 1413 observed reflections led to a final conventional R value of 0.093. The 18-C-6 complex belongs to the triclinic space group P1 with a=8.414(4), b=12.193(6), c=12.394(6) Å, =73.14(4), =86.07(4), =81.52(4)^o, and Z=2 for =1.45 g cm^–3. Refinement based on 2605 observed reflections led to R=0.063. The complex aluminum-containing species are related to a class of compounds called aluminoxanes.     

In-depth analysis on thermal phase transition mechanism of main-chain phosphorus-containing thermotropic liquid crystal copolyester

In order to surmount drawbacks of the infrared spectroscopy (IR) itself during investigating the mesophase-transition behaviours and mechanism of the thermotropic liquid crystalline polymers (TLCPs), the elemental phosphorus as an internal marker was introduced into the main-chain TLCPs. The detail mechanism of the glass transition and mesophase phase transition of the phosphorus-containing aromatic liquid crystalline copolyester (poly(-hydroxybenzate-co-DOPO-benzenediol dihydrodiphenyl ether terephthalate) [PHDDT]) was revealed through tracing the internal marker with the perturbation correlation moving window 2-dimensional correlation and 2-dimensional correlation analysis (2DCOS) correlation IR spectra. The results showed that the phosphorus-containing unit did not participate in the glass transition of the PHDDT. The results of the 2DCOS showed that the PHDDT mesophase phase transition took place through adjustment of the phosphorus-containing units. Simultaneously, the adjustment of the phosphorus-containing unit also can induce the motion of the other groups, and the sequential orders of the spectral changes were Ar–O–Ar → ester C–O → C=O. However, the sequential orders of the spectral changes were converse during the PHDDT glass transition.     

胆甾液晶二氮杂冠醚-Eu(Ⅲ)配合物LB膜和荧光性质研究

研究了胆甾液晶二氮杂冠醚N,N'-双[胆甾-5-烯-3β-氧羰甲基]-1,10-二氮-4,7,13,16-四氧环十八烷(1)及其与Eu³⁺的配合物(2)、2与苯甲酸的混配物(3)的LB膜和荧光性质.结果表明:1、2和3都在水溶液亚相液面形成稳定的单分子膜,但只有1的单分子面积受亚相pH的影响.1、2和3的单分子膜都容易转移到石英基片上形成LB膜,其中2和3为X型,转移比分别为0.6和1.0.在LB膜中,在2的荧光激发波长范围比在溶液中的宽,荧光强度也比在溶液中的强得多.在2中添加苯甲酸形成3可改善LB膜中分子有序排列,荧光强度增强到无苯甲酸时的2.0倍.所有这些LB膜,即使添加了苯甲酸的,都不是很稳定.     

冠醚-离子液体体系对水相中锶离子的萃取研究

本文研究了以一系列离子液体作为介质时,萃取剂二环己基18冠6（DCH18C6）对水相中Sr^2＋的萃取行为．研究结果表明,DCH18C6／离子液体体系对Sr^2＋的萃取性能优于相应的DCH18C6／JE辛醇萃取体系,一定条件下其萃取Sr^2＋的分配比可达10^3量级．同时,体系对Sr^2＋的萃取性能随着离子液体的结构不同而有所差别．在离子液体萃取体系中,随着水相初始硝酸浓度的增加,对Sr^2＋的萃取性能下降．水相中Na^＋、K^＋等离子的存在也会对体系萃取Sr^2＋产生直接影响．本文还验证了离子液体体系萃取Sr^2＋的机理,即以阳离子交换机理为主实现对Sr^2＋的萃取．     

Thermal transition of a wholly aromatic thermotropic liquid crystalline copolyester

A copolyester was prepared from p-hydroxybenzoic acid (HBA), 2,6-naphthalene dicaboxylic acid (NDA), and hydroquinone (HQ). Thermal transition behavior and the crystal structure of this copolyester were investigated by using polarized light microscopy (PLM), differential scanning calorimetry (DSC), and wide-angle X-ray diffraction (WAXD) after annealing at solid-phase polymerization conditions. A glass transition or newly ordered structure in the 270–290°C range was observed on annealing at 260°C, which increased with annealing time, attributed to mobility and reactive rearrangement in amorphous regions. Broad and unclear WAXD profiles and multimelting behaviors were found on annealing at 280°C, and explained by hexagonal and orthorhombic lattice formation and transformation. A large increase in melting temperature was observed only on annealing at a temperature (320°C) near the crystal–nematic transition, suggesting annealing temperatures near the melting point are required for sufficient mobility to afford crystalline rearrangement via transesterification. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3763–3769, 1999     

Effect of cholesteric liquid crystalline elastomer with binaphthalene crosslinkings on thermal and optical properties of a liquid crystal that show smectic A‐cholesteric phase transition

A side‐chain polysiloxane cholesteric liquid crystalline elastomer (ChLCE) with binaphthalene derivate as crosslinkings and cholesterol derivate as liquid crystalline monomers was designed and synthesized. A binaphthyl chiral dopant (CD) was synthesized as well. The chemical structures and liquid crystalline properties of the ChLCE and the CD were characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, element analyses, differential scanning calorimetry and polarizing optical microscopy measurements. The helical twisting power of the ChLCE exhibited a turning point with changing temperature and was smaller than that of the CD. In addition, the effect of the ChLCE on phase transition temperatures and thermal‐optical properties of a liquid crystal that show smectic A (SmA)‐cholesteric (Ch) phase transition was studied. Worthily, the testing of the reflection wavelength with changing temperature suggested that the adding of the ChLCE in liquid crystals that show SmA‐Ch phase transition can expedite their SmA‐Ch transition. In addition, the network structure of the ChLCE may play a significant role in the accelerating of the transition. These properties provided theoretical and experimental foundations for applying ChLCE in thermally sensitive liquid crystal devices requiring fast response, such as thermally controllable windows, materials and displays. Copyright © 2012 John Wiley & Sons, Ltd.