离子液体参与构建的胶束

离子液体参与构建的有序组合体,以其独特的物理化学性质及在众多领域的应用潜能而引起广泛关注。本文结合我们的研究工作,对离子液体参与构建的胶束体系的主要研究成果进行了综述,重点介绍了传统表面活性剂在离子液体中胶束的形成、表面活性离子液体在水溶液中的聚集行为、离子液体作为添加剂对传统表面活性剂胶束的影响。在此基础上,归纳了部分体系胶束形成的机理和规律,并展望了离子液体构建的胶束体系研究和发展的方向。     

混合离子液体对聚甲基丙烯酸甲酯分子链缠结及松弛行为的影响

首先通过两步法合成了具有双咪唑环阳离子结构的离子液体(DIL),并将其与单咪唑环离子液体(MIL)进行混合以调控黏度变化,混合离子液体(ILs)的黏度符合对数混合规则且随温度变化呈现Arrhenius型流体行为.进一步通过动态流变、示差扫描量热(DSC)、电化学测试等方法研究了混合离子液体中DIL比例对聚甲基丙烯酸甲酯(PMMA)链缠结和松弛行为的影响,并讨论了PMMA/ILs体系热稳定性、玻璃化转变及离子电导率等的变化.结果表明,DIL独特的双咪唑环结构可与PMMA分子形成更多相互作用位点,从而导致凝聚缠结的形成,很大程度上限制了PMMA分子链的运动和松弛.随DIL含量增加,PMMA/ILs体系的松弛时间、热分解温度、玻璃化转变温度等参数均呈增大趋势,但其离子电导率有所损失,这与DIL较大的分子尺寸和运动能力有关.     

咪唑类离子液体的研究进展

咪唑类离子液体以其独特的物理化学性质和在众多领域的巨大应用潜能而引起广泛的关注.本文结合我们的研究工作,对近期国际上关于咪唑类离子液体的气-液和液-液平衡、咪唑类离子液体的表面活性剂行为、传统表面活性剂在咪唑类离子液体中聚集体的形成、表面活性剂/水(油)/咪唑类离子液体三元体系超分子自组装体形成等方面的一些主要研究成果进行了综合评述.在此基础上,提出了进一步开展非传统表面活性剂/离子液体体系超分子自组装体及离子液体结构对聚集体形成、结构、性质影响等研究的设想.     

室温离子液体中的有序分子组合体

评述了室温离子液体中形成有序分子组合体包括液晶、胶束、囊泡、微乳液和乳状液的研究进展,展望了这种新型有序体系的研究发展趋势.     

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评述了室温离子液体中形成有序分子组合体包括液晶、胶束、囊泡、微乳液和乳状液的研究进展．展望了这种新型有序体系的研究发展趋势。     

非水溶剂中囊泡等分子有序组合体的形成

总结了各类表面活性剂在乙醇等非水及混合溶剂中的囊泡、胶束等聚集体的形成规律,着重讨论了非水体系中介电常数改变对正负离子表面活性剂混合体系中聚集体形成的影响.对反胶束等不同分子有序组合体在非水体系中的形成情况也进行了概述.     

不同离子液体反应介质在生物催化中的应用研究进展

离子液体(ILs)因其独特物理化学性质成为新型反应溶剂和催化剂,在生物催化反应中有着广阔的应用前景。根据不同ILs的水溶性,其与水可形成4种反应介质,即微水ILs单相体系、亲水性ILs-水单相体系、疏水性ILs-水两相体系和ILs微乳液体系。本文分别介绍了不同ILs反应体系中生物催化剂的催化活性、稳定性和选择性,综述了这些体系中的生物催化反应研究进展。     

4-氨基邻苯二甲酰亚胺衍生物作为荧光探针的应用

介绍了近年来4-氨基邻苯二甲酰亚胺(AP)类荧光探针在主-客体化学、金属离子测定、溶剂化动力学及各种有序分子聚集体(如胶束、反胶束)性质研究方面的进展。     

CO2/离子液体体系热力学性质的分子动力学模拟

超临界CO2和离子液体(ILs)是两种绿色溶剂. 离子液体可以溶解超临界CO2, 而超临界CO2不能溶解离子液体. 由此设计构成的CO2/IL二元系统, 同时具备了超临界CO2和离子液体的许多优点: 既可以降低离子液体的粘度, 还便于相分离, 是新型的耦合绿色溶剂. 其物理化学性质对于设计反应、分离等过程非常重要. 因此, 本文以CO2/IL二元系统为研究对象, 通过选择合适的分子力场和系综, 运用分子动力学(MD)模拟方法研究了CO2/[bmim][PF6]、CO2/[bmim][NO3]等体系的热力学性质. 结果表明, CO2对ILs膨胀度的影响非常小, 当CO2摩尔分数为0.5时, ILs膨胀仅为15%. CO2/ILs的扩散系数远小于CO2膨胀甲醇、乙醇溶液的扩散系数. 随着CO2含量的增加, ILs的扩散系数提高, 粘度显著下降, 表明CO2能有效地改善ILs扩散性, 减小其粘度. 因此CO2可用以改善离子液体溶剂体系的传递特性, 增强反应分离过程在其中的进行.     

关于限域离子液体吸附CO_2的密度泛函理论(DFT)的研究

近年来,温室效应日趋严重,因此吸收CO_2的材料受到了广泛的关注.采用了密度泛函理论(DFT)研究以SiO_2为载体的限域离子液体对CO_2的吸附.对比纯净离子液体(ILs)以及限域离子液体与CO_2的相互作用情况,在这两种状态下两种体系的吸附情况大不相同.从几何结构、相互作用以及电荷分析等方面对ILs、 SiO_2以及ILs/SiO_2复合结构进行研究.计算结果表明,载体、离子液体和CO_2之间都存在较强的相互作用.离子液体的负载不仅改变了SiO_2载体的结构,而且受载体的影响阴阳离子之间的相互作用力也发生了改变.计算结果为进一步深入限域离子液体对CO_2的吸附打下了理论基础.     

Anionic surfactant ionic liquids with 1-butyl-3-methyl-imidazolium cations: characterization and application

For the first time a series of anionic surfactant ionic liquids (SAILs) has been synthesized based on organic surfactant anions and 1-butyl-3-methyl-imidazolium cations. These compounds are more environmentally friendly and chemically tunable as compared to other common ionic liquids. A detailed investigation of physicochemical properties highlights potential applications from battery design to reaction control, and studies into aqueous aggregation behavior, as well as structuring in pure ILs, point to possible uses in electrochemistry.     

Recent advances in surface-active ionic liquid-assisted self-assembly systems for drug delivery

Surface-active ionic liquids (SAILs) are receiving growing interest as environmentally friendly designer surfactants for various applications, including drug formulation and delivery. The use of SAILs in the pharmaceutical industry has the potential to address the challenges associated with conventional surfactants. The tunable formation of complementary ion pairs from a diverse range of ions enables the task-specific optimization of SAILs. SAILs comprising second and third-generation cations and anions have been used to design biocompatible self-assembled systems including micelles, microemulsions, vesicles, liposomes, and nanoparticles for drug delivery carriers. Compared with conventional surfactant-based carriers, SAIL-based systems offer better pharmacokinetic and pharmacodynamic properties. This mini-review highlights recent findings on the formation of ionic liquid-based self-assembled systems and their potential applications in drug delivery.     

Synthesis and Characterization of Surface-Active Ionic Liquids Used in the Disruption of Escherichia Coli Cells

Twelve surface-active ionic liquids (SAILs) and surface-active derivatives, based on imidazolium, ammonium, and phosphonium cations and containing one, or more, long alkyl chains in the cation and/or the anion, were synthetized and characterized. The aggregation behavior of these SAILs in water, as well as their adsorption at solution/air interface, were studied by assessing surface tension and conductivity. The CMC values obtained (0.03–6.0 mM) show a high propensity of these compounds to self-aggregate in aqueous media. Their thermal properties were also characterized, namely the melting point and decomposition temperature by using DSC and TGA, respectively. Furthermore, the toxicity of these SAILs was evaluated using the marine bacteria Aliivibrio fischeri (Gram-negative). According to the EC₅₀ values obtained (0.3–2.7 mg L⁻¹), the surface-active compounds tested should be considered “toxic” or “highly toxic”. Their ability to induce cell disruption of Escherichia coli cells (also Gram-negative), releasing the intracellular green fluorescent protein (GFP) produced, was investigated. The results clearly evidence the capability of these SAILs to act as cell disruption agents.     

Anionic surfactants and surfactant ionic liquids with quaternary ammonium counterions

Small-angle neutron scattering and surface tension have been used to characterize a class of surfactants (SURFs), including surfactant ionic liquids (SAILs). These SURFs and SAILs are based on organic surfactant anions (single-tail dodecyl sulfate, DS, double-chain aerosol-OT, AOT, and the trichain, TC) with substituted quaternary ammonium cations. This class of surfactants can be obtained by straightforward chemistry, being cheaper and more environmentally benign than standard cationic SAILs. A surprising aspect of the results is that, broadly speaking, the physicochemical properties of these SURFs and SAILs are dominated by the nature of the surfactant anion and that the chemical structure of the added cation plays only a secondary role.     

Extraction of organic compounds with room temperature ionic liquids

Room temperature ionic liquids are novel solvents with a rather specific blend of physical and solution properties that makes them of interest for applications in separation science. They are good solvents for a wide range of compounds in which they behave as polar solvents. Their physical properties of note that distinguish them from conventional organic solvents are a negligible vapor pressure, high thermal stability, and relatively high viscosity. They can form biphasic systems with water or low polarity organic solvents and gases suitable for use in liquid–liquid and gas–liquid partition systems. An analysis of partition coefficients for varied compounds in these systems allows characterization of solvent selectivity using the solvation parameter model, which together with spectroscopic studies of solvent effects on probe substances, results in a detailed picture of solvent behavior. These studies indicate that the solution properties of ionic liquids are similar to those of polar organic solvents. Practical applications of ionic liquids in sample preparation include extractive distillation, aqueous biphasic systems, liquid–liquid extraction, liquid-phase microextraction, supported liquid membrane extraction, matrix solvents for headspace analysis, and micellar extraction. The specific advantages and limitations of ionic liquids in these studies is discussed with a view to defining future uses and the need not to neglect the identification of new room temperature ionic liquids with physical and solution properties tailored to the needs of specific sample preparation techniques. The defining feature of the special nature of ionic liquids is not their solution or physical properties viewed separately but their unique combinations when taken together compared with traditional organic solvents.     

Design of functional guanidinium ionic liquid aqueous two-phase systems for the efficient purification of protein

A series of novel cationic functional hexaalkylguanidinium ionic liquids and anionic functional tetraalkylguanidinium ionic liquids have been devised and synthesized based on 1,1,3,3-tetramethylguanidine. The structures of the ionic liquids (ILs) were confirmed by ¹H nuclear magnetic resonance (¹H NMR) and 13C nuclear magnetic resonance (13C NMR) and the production yields were all above 90%. Functional guanidinium ionic liquid aqueous two-phase systems (FGIL-ATPSs) have been first designed with these functional guanidinium ILs and phosphate solution for the purification of protein. After phase separation, proteins had transferred into the IL-rich phase and the concentrations of proteins were determined by measuring the absorbance at 278 nm using an ultra violet visible (UV–vis) spectrophotometer. The advantages of FGIL-ATPSs were compared with ordinary ionic liquid aqueous two-phase systems (IL-ATPSs). The proposed FGIL-ATPS has been applied to purify lysozyme, trypsin, ovalbumin and bovine serum albumin. Single factor experiments were used to research the effects of the process, such as the amount of ionic liquid (IL), the concentration of salt solution, temperature and the amount of protein. The purification efficiency reaches to 97.05%. The secondary structure of protein during the experimental process was observed upon investigation using UV–vis spectrophotometer, Fourier-transform infrared spectroscopy (FT-IR) and circular dichroism spectrum (CD spectrum). The precision, stability and repeatability of the process were investigated. The mechanisms of purification were researched by dynamic light scattering (DLS), determination of the conductivity and transmission electron microscopy (TEM). It was suggested that aggregation and embrace phenomenon play a significant role in the purification of proteins. All the results show that FGIL-ATPSs have huge potential to offer new possibility in the purification of proteins.     

Liquid Phase Behavior in Systems of 1-Butyl-3-alkylimidazolium bis{(trifluoromethyl)sulfonyl}imide Ionic Liquids with Water: Influence of the Structure of the C5 Alkyl Substituent

In the present paper a study of the liquid phase behavior in aqueous systems of imidazolium-based ionic liquids (ILs) with the bis{(trifluoromethyl)sulfonyl}imide anion is addressed. To highlight the influence of the C5 alkyl side group structure on their properties, a series of ILs with linear, branched, and cyclic substituents was studied. As was already shown in our previous work, very subtle changes in the cation structure at the molecular scale can have a significant and unexpected impact on the bulk properties. Therefore, in this work, the mutual solubilities of 1-butyl-3-alkylimidazolium bis{(trifluoromethyl)sulfonyl}imide ionic liquids and water were studied, both experimentally and by modeling, at atmospheric pressure as a function of temperature from 293.15 to 328.15 K. The solubilities of the ionic liquids in water are very low, typically around 10^?5 mole fraction units and were measured by a direct analytical method, making use of UV–Vis spectrophotometry. The solubilities of water in the ionic liquids were found to be around 0.20 mole fraction units and were measured using the cloud-point method. In addition to the experimental data, the liquid–liquid equilibria in the systems were modeled using the COSMO-RS methodology. Phase diagrams and the critical solution points were also estimated by applying the universal scaling laws based on the 3D Ising model, taking into account the non-linearity of the diameter and crossover to mean-field behavior.     

离子液体表面活性剂1-丁基-3-甲基咪唑烷基硫酸酯的合成及其在水溶液中的聚集行为

采用离子交换法,由1-丁基-3甲基咪唑氯盐（C4mimCl）和烷基硫酸钠合成了一系列无卤素的阴离子表面活性离子液体—1-丁基-3-甲基咪唑烷基硫酸酯[C4mim][CnH2n 1SO4](n=8,12,16),利用表面张力仪、稳态荧光光谱等手段考察了表面活性离子液体在水溶液表面及体相中的聚集行为,结果表明,与传统无机反离子相比,有机咪唑阳离子[C4mim] 作为反离子的离子液体型表面活性剂具有较高的表面活性,[C4mim] 产生的氢键引起的抑制分子规则排列的作用小于其促进分子有序排列的疏水作用。长烷基链的阴离子是界面膜及胶束的主要组成成分,阴离子疏水烷基碳链的增长虽然可促进胶束的形成,但却在一定程度上抑制[C4mim] 离子参与界面或胶束的形成;阴离子所带烷基链越长,越不利于阳离子[C4mim]＋参与界面膜或胶束的形成,界面膜或胶束中表面活性剂排布越松散,即界面张力越大,体系中胶束聚集数较小。     

Controlling the aqueous miscibility of ionic liquids: aqueous biphasic systems of water-miscible ionic liquids and water-structuring salts for recycle,metathesis, and separations

Hydrophilic ionic liquids can be salted-out and concentrated from aqueous solution upon addition of kosmotropic salts forming aqueous biphasic systems as illustrated by the phase behavior of mixtures of 1-butyl-3-methylimidazolium chloride ([C4mim]Cl) and K3PO4.     

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.