磁性离子液体的应用研究

磁性离子液体是指能够吸附在磁铁上,在外加磁场作用下具有一定磁化强度的离子液体。本文综述了自2004年磁性离子液体概念提出至今在各领域的应用,其可以催化吡咯、3-甲基噻吩等单体合成导电高分子纳米微球,同时起到溶剂和模板的作用;还可以通过外加磁场调整产物的微观结构和形貌,从而得到不同的纳米结构;它也可以充当Lewis酸催化剂,催化傅克反应等一系列化学反应,并可以回收重复使用,而且回收有望通过磁场简单实现;与碳纳米管以共价键结合可以制备具有磁性的碳纳米管。除此之外,磁性离子液体在光控顺磁性超分子体系、吸收有机挥发物等领域的应用在近年也陆续有报道。     

离子液体支撑液膜分离CO2

支撑液膜是一种在湿法冶金、生物技术以及气体分离等多个领域都有应用的重要膜分离技术。本文回顾了支撑液膜技术分离CO2的研究进展,按照液膜相的不同,分类介绍了常规载体支撑液膜和离子液体支撑液膜,指出了常规载体支撑液膜分离CO2的局限性,重点介绍了离子液体支撑液膜分离CO2的发展,分析了气体在离子液体支撑液膜中的传质机理以及常规离子液体结构、含量和支撑膜材料等对分离效果的影响;讨论了离子液体的功能化方法以及功能化离子液体支撑液膜分离CO2的渗透率、选择性和液膜稳定性;介绍了两种新的离子液体支撑液膜改进方法:聚离子液体膜与凝胶化离子液体支撑液膜。最后指出了今后用于CO2分离的离子液体支撑液膜的发展方向。     

Supported ionic liquid catalysis--a new concept for homogeneous hydroformylation catalysis

The new concept of supported ionic liquid catalysis involves the surface of a support material that is modified with a monolayer of covalently attached ionic liquid fragments. Treatment of this surface with additional ionic liquid results in the formation of a multiple layer of free ionic liquid on the support. These layers serve as the reaction phase in which a homogeneous hydroformylation catalyst was dissolved. Supported ionic liquid catalysis combines the advantages of ionic liquid media with solid support materials which enables the application of fixed-bed technology and the usage of significantly reduced amounts of the ionic liquid. The concept of supported ionic liquid catalysis has successfully been used for hydroformylation reactions and can be further expanded into other areas of catalysis.     

Preparation of Ionic Liquid‐based Vilsmier Reagent from Novel Multi‐purpose Dimethyl Formamide‐like Ionic Liquid and Its Application

In continuation of research to explore the applied potential of DMF‐like ionic liquid, the ionic liquid version of N,N‐dimethyliminiumchloride (Vilsmier reagent) has been synthesized from DMF‐like ionic liquid and tested effectively for its capacity to achieve more useful organic transformations. The results show that DMF‐like ionic liquid is world's first task specific ionic liquid which has catalyzed numerous diverse type of reaction and is multipurpose in its application. Thus a new term for this DMF‐like ionic liquid has been coined that is DMF‐like "multipurpose" ionic liquid.     

Development of Ionic Liquids as Green Reaction Media and Catalysts

A brief review of the work carried out at Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences for development of ionic liquid as green reaction media and catalysts is presented. This includes the processes of ionic liquid to be used as catalyst, reaction media, development of functional ionic liquid and methods for synthesis of immobilized ionic liquid. In the end, some prospects for development of ionic liquid are also addressed.     

利用双水相分离回收离子液体的研究进展

研究离子液体的分离与回收对于减少离子液体对环境的影响、提高离子液体的利用效率、降低离子液体的应用成本、促进离子液体的工业应用具有重要的意义.本文重点综述了利用无机盐-离子液体双水相、糖-离子液体双水相、聚合物-离子液体双水相和CO2诱导的离子液体双水相技术分离回收离子液体的研究进展,分析了影响离子液体分离回收的关键因素,评价了不同离子液体双水相体系的优缺点,展望了该领域的发展方向及面临的挑战.     

Influence of water on the surface of the water-miscible ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate: a sum frequency generation analysis

Sum frequency generation spectroscopy (SFG) was used to study the influence of water on the surface of the water-miscible ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate. The orientation of the cation at the gas-liquid interface was analyzed as a function of ionic liquid concentration in water for concentrations from 0 to 1 mole fraction of the ionic liquid. The cation was found to be oriented with the imidazolium ring nearly parallel to the surface plane with a tilt angle > or = 70 degrees when the ionic liquid was dry. Furthermore, no noticeable change in the orientation was observed when high concentrations of water were mixed with the ionic liquid. The cation butyl chain is projecting into the gas phase with a CH(3) tilt angle of 54 +/- 2 degrees when the ionic liquid is dry and 46 +/- 4 degrees when mixed with water. Water is oriented at the surface only for concentration < or = 0.02 mole fraction of the ionic liquid. At higher ionic liquid concentrations (mole fractions > or = 0.05) the gas-liquid interface resembles that of the pure ionic liquid.     

基于双醛基功能化离子液体构建电化学免疫传感器

合成了含双醛基的离子液体,此离子液体一端的醛基与修饰在电极表面的氨基发生共价键作用,将离子液体修饰在电极表面,另一端的醛基可用来固定抗体,构建电化学免疫传感器,实现对心肌肌钙蛋白I(cTnI)的检测。离子液体通过共价键作用固定在电极表面,不仅减少了从电极表面向检测溶液的渗透,提高传感器的稳定性,而且还可以直接固定抗体,不需要使用其他交联试剂;同时,离子液体可增强传感界面的导电性,提高传感器的灵敏度。在优化的实验条件下,传感器的线性范围为0.1~40 ng/mL,检出限为0.06 ng/mL。     

固定化离子液体在有机合成中的应用

固定化离子液体是将离子液体通过物理吸附或化学键合等方法与固载材料结合而成,不仅保持了离子液体稳定性好、挥发性低、结构可优化等特点,还提高了离子液体的催化活性和重复利用性。固定化离子液体广泛应用于缩合、偶联及不对称合成等反应中。本文介绍了固定化离子液体的制备、固载材料的分类、结合方式及固定化离子液体在有机合成中的应用进展。     

Interfacial tension and wetting behavior of air/oil/ionic liquid systems

We measured the interfacial tension and the density of air/n-hexane, n-decane, 1-perfluorohexane/1-hexyl-3-methyl-imidazolium hexafluorophosphate systems as a function of temperature. From the air/ionic liquid surface tension values, it was suggested that Coulombic interaction between imidazolium cations and counter anions are not so much different between the surface and bulk. The density values indicated that the decrease of surface tension by saturating organics was closely correlated to the mutual solubility between ionic liquid and organics. Interfacial tension at the oil/ionic liquid interfaces suggested that ionic liquid molecules were more ordered at the oil/ionic liquid interfaces compared to the air/ionic liquid interfaces, but the decrease of the entropy due to the interfacial orientation of ionic liquid was compensated by the increase of the entropy due to the contact of different chemical species. The initial spreading coefficients and the Hamaker constants indicated that all the oil phases spread at the air/ionic liquid interfaces spontaneously, and form the complete wetting films.     

离子液体催化制备5-羟甲基糠醛的研究进展

本文综述了离子液体催化制备5-羟甲基糠醛的研究进展。运用离子液体作为反应溶剂和催化剂,与常规合成HMF的方法相比,其反应在常压、低温下进行,更易于操作控制;副反应数量明显减少,HMF的产率稳定,可达90%;离子液体催化活性稳定,可重复利用,减少了有机溶剂的使用量;利用离子液体作为媒介,能将反应原料从单一的果糖扩展到葡萄糖和纤维素等廉价原料,降低了生产成本。由此可见,运用离子液体催化制备HMF将是今后研究的重点和发展的必然趋势。     

聚苯胺在离子液体/水体系中的微乳液法合成

通过乳化剂OP-10的乳化作用,将油相为溶有苯胺单体的1-丁基-3-甲基咪唑六氟磷酸盐([bmim]PF6)离子液体与水形成了水包油型微乳液.利用该微乳液制备了纳米粒径的导电聚苯胺颗粒.红外光谱和能量散射谱分析结果表明,离子液体负离子已掺杂进入聚苯胺分子链,所得聚苯胺颗粒热稳定性和电化学稳定性好,且具有良好的充放电性能.     

咪唑类离子液体结构与熔点的构效关系及其基本规律

熔点是界定、研究离子液体及其使用过程的一个重要参考指标,因此研究离子液体分子结构与熔点之间的构效关系及其基本规律有特别重要的意义。本文以从近两百遍文献及Beilstein Gmelin网络数据库中收集的约900种咪唑类离子液体中的384种咪唑类离子液体的熔点数据为依据,考察了离子液体分子结构与熔点之间的构效关系及其基本规律,这对离子液体的设计合成及应用有指导作用。     

Influence of the ionic liquid/gas surface on ionic liquid chemistry

Applications such as gas storage, gas separation, NP synthesis and supported ionic liquid phase catalysis depend upon the interaction of different species with the ionic liquid/gas surface. Consequently, these applications cannot proceed to the full extent of their potential without a profound understanding of the surface structure and properties. As a whole, this perspective contains more questions than answers, which demonstrates the current state of the field. Throughout this perspective, crucial questions are posed and a roadmap is proposed to answer these questions. A critical analysis is made of the field of ionic liquid/gas surface structure and properties, and a number of design rules are mined. The effects of ionic additives on the ionic liquid/gas surface structure are presented. A possible driving force for surface formation is discussed that has, to the best of my knowledge, not been postulated in the literature to date. This driving force suggests that for systems composed solely of ions, the rules for surface formation of dilute electrolytes do not apply. The interaction of neutral additives with the ionic liquid/gas surface is discussed. Particular attention is focussed upon H(2)O and CO(2), vital additives for many applications of ionic liquids. Correlations between ionic liquid/gas surface structure and properties, ionic liquid surfaces plus additives, and ionic liquid applications are given.     

Solubilization of an Ionic Liquid,l-Butyl-3-methylimidazolium Hexafluorophosphate,in a Surfactant-Water System

The amphiphilic association structures were determined in the system; water, Laureth 4 (approximately C₁₂(EO) ₄), and the ionic liquid l-butyl-3-methylimidazolium hexafluorophosphate ([bmim[PF₆]), using visual observation and small angle x-ray diffraction. The system showed a lamellar liquid crystal solubilizing the ionic liquid ([bmim[PF₆]) to a maximum of 15%, an isotropic surfactant solution dissolving the ionic liquid to a maximum of 39%, an isotropic ionic liquid solution with less than 0.5% of water and surfactant and finally, an aqueous solution with only traces of surfactant and ionic liquid. The small angle x-ray diffraction results showed the ionic liquid to be solubilized into the lamellar liquid crystal without changing the dimensions of the amphiphile layer or the interlayer spacing dependence on the water content.     

Poly(ethylene glycol)-lipase complexes that are highly active and enantioselective in ionic liquids

Lipase-catalyzed alcoholysis between vinyl acetate and 2-phenyl-1-propanol was investigated in dialkylimidazolium-based ionic liquids. Although native lipase powder exhibited very low activity in an ionic liquid, forming a poly(ethylene glycol)(PEG)-lipase complex improved the lipase activity in the ionic liquid. The activity of the PEG-lipase complex was higher in ionic liquids than in common organic solvents (n-hexane, isooctane and dimethylsulfoxide). Fluorescence measurements using 4-aminophthalimide revealed that the ionic liquids were more hydrophilic than the organic solvents used for non-aqueous enzymology. A kinetic study of lipase-catalyzed alcoholysis in an ionic liquid ([Bmim][PF6]) revealed that the Michaelis constant (Km) for 2-phenyl-1-propanol in the ionic liquid was half that in n-hexane, suggesting that the ionic liquid stabilized the enzyme-substrate complex. Finally, we carried out enantioselective alcoholysis of 1-phenylethanol in ionic liquids employing the PEG-lipase complex, and obtained high enantioselectivity, comparable to that in n-hexane.     

CO(2) as a separation switch for ionic liquid/organic mixtures

A novel technique to separate ionic liquids from organic compounds is introduced which uses carbon dioxide to induce the formation of an ionic liquid-rich phase and an organic-rich liquid phase in mixtures of methanol and 3-butyl-1-methyl-imidazolium hexafluorophosphate ([C4mim][PF6]). If the temperature is above the critical temperature of CO2 then the methanol-rich phase can become completely miscible with the CO2-rich phase, and this new phase is completely ionic liquid-free. Since CO2 is nonpolar, it is not equipped to solvate ions. As the CO2 dissolves in the methanol/[C4mim][PF6] mixture, the solvent power of the CO2-expanded liquid is significantly reduced, inducing the formation of the second liquid phase that is rich in ionic liquid. This presents a new way to recover products from ionic liquid mixtures and purify organic phases that have been contaminated with ionic liquid. Moreover, these results have important implications for reactions done in CO2/ionic liquid biphasic mixtures.     

PEG型酸性温控离子液体中芳香酸和醇的酯化反应

报道了该催化体系在芳香酸和醇酯化反应中的应用. 研究发现, 该离子液体具有优良的催化性能, 产品易分离, 催化剂可循环使用且活性不降低, 催化剂不易流失, 实现了均相催化剂的高效回收和再利用.     

染料敏化纳米薄膜太阳电池中离子液体基电解质的研究进展

综述了离子液体基电解质在染料敏化纳米薄膜太阳电池中的研究及应用进展，详细论述了多种离子液体基电解质系统对染料敏化纳米薄膜太阳电池性能的影响，并比较了这些系统的优缺点. 根据胶凝剂的不同分别论述了离子液体基电解质的固化及其对电池性能的影响. 评述了离子液体基电解质在大面积电池中的应用，并对离子液体基电解质未来发展方向进行了展望.     

Incorporation of ionic liquid into porous polymer monoliths to enhance the separation of small molecules in reversed‐phase high‐performance liquid chromatography

An ionic liquid was incorporated into the porous polymer monoliths to afford stationary phases with enhanced chromatographic performance for small molecules in reversed‐phase high‐performance liquid chromatography. The effect of the ionic liquid in the polymerization mixture on the performance of the monoliths was studied in detail. While monoliths without ionic liquid exhibited poor resolution and low efficiency, the addition of ionic liquid to the polymerization mixture provides highly increased resolution and high efficiency. The chromatographic performances of the monoliths were demonstrated by the separations of various small molecules including aromatic hydrocarbons, isomers, and homologues using a binary polar mobile phase. The present column efficiency reached 27 000 plates/m, which showed that the ionic liquid monoliths are alternative stationary phases in the separation of small molecules by high‐performance liquid chromatography