离子液体对气体的溶解性研究进展

概述了不同离子液体对CO2,O2,SO2,CH4等以及烯烃和烷烃气体的溶解性。文献资料分析表明,气体在离子液体中的溶解性差别很大,离子液体中的阴离子对气体的溶解度影响较大,而阳离子的影响较小。大部分气体在离子液体中的亨利系数随温度的升高而增大。气体在[bmim][PF6]中的溶解度比在[bmim][BF4]中的稍大。低温时[bmim][PF4]离子液体对CO2气体的吸收效果较好;[hmim][Tf2N]离子液体对SO2气体的吸收较好。在将离子液体用于气体吸收时可优先考虑Tf2N^-阴离子和具有较长侧链的咪唑型离子液体。     

离子液体在气体吸附中的研究进展

综述了气体在离子液体中的溶解性能、影响因素及其传质机理;介绍了CO2、SO2等气体在离子液体中的吸附研究进展;总结了离子液体中气体分离、分析及有气体参与的化学反应等领域的研究现状,并展望了离子液体在气体吸附方面的应用前景。     

离子液体气体干燥技术的研究进展

离子液体（ionic liquids, ILs）被视为化工中传统溶剂的优良替代物,使用它们作为溶剂吸收可凝性气体时,具有溶剂损失少、无腐蚀和稳定性强等优点。一些ILs具有很强的吸水性,所以在气体干燥领域ILs受到了广泛关注。本文介绍了用于预测气体在ILs中溶解度的预测型分子热力学模型和气体在ILs中的实验测量方法,具体分析了ILs对CH₄、CO₂等气体的干燥机理和工艺,最后对ILs用于气体干燥的基础研究作出展望。     

咪唑类离子液体溶解纤维素的研究进展

纤维素作为一种最丰富的可再生自然资源具有很好的开发前景,但由于纤维素多氢键的超分子结构,致使其不溶于普通的有机溶剂,限制了其应用。而离子液体的出现为纤维素的应用提供了一个广阔的平台。本文综述了纤维素在咪唑类离子液体中的溶解性能及可能的溶解机理。总结指出阴离子为Cl-、CH3CHOO-和(MeO)RPO2-的离子液体对纤...     

离子液体在溶解方面的研究进展

离子液体作为一种新型的“绿色溶剂”,广泛应用于化学反应、萃取分离等化工过程。介绍了绿色溶剂——离子液体发展状况,详细讨论了离子液体在溶解方面的研究进展,包括离子液体在萃取分离方面的研究、离子液体作为反应过程中的溶剂以及离子液体作为高分子溶剂的研究。     

离子液体中天然纤维素的溶解研究进展

纤维素是广泛存在的自然资源,普遍应用于石油、医药、电子等行业。但是由于纤维素的本身化学性质使其难以加工。传统的黏胶法与铜氨法由于其生产条件严苛,污染环境,已经不再适合新时代对于绿色化学的要求。近年来,绿色高效的离子液体得到研究开发,为纤维素的发展提供一个新的平台。本文综述了当前纤维素的几种溶解体系及其概况,探讨了各个体系优缺点,并着重介绍了近年来离子液体的研究进展,提出了今后离子液体应用于纤维素的几个方向,以期为今后纤维素溶解及开发更多纤维素材料提供参考。     

离子液体支撑液膜技术及其在气体分离中的研究进展

分析离子液体支撑液膜的气体分离机理,总结目前离子液体支撑液膜的制备方法以及不同膜材料、不同离子液体及其亲疏水性对离子液体支撑液膜稳定性的影响。介绍离子液体支撑液膜在气体分离中的应用,对离子液体支撑液膜的工业化前景进行了展望。     

离子液体溶解木质纤维素及其组分研究进展

木质纤维素是地球上含量极丰富的可再生资源。用离子液体溶解木质纤维素材料及其组分进而生产生物质能源产品是一种新型环保的木质纤维素利用方法。对离子液体溶解木质纤维素材料及其组分的研究进展进行了综述,并对离子液体在生物质能源中的应用前景进行了展望。     

TATB在离子液体-DMSO复合溶剂体系中的溶解性实验研究

针对1,3,5-三氨基-2,4,6-三硝基苯(TATB)的分子结构特点,选择以下几种离子液体,阳离子主要包括三乙胺类、吡啶类和甲基咪唑类,阴离子包括Br-、NO3-、CF3COO-、CH3COO-,考察了TATB在离子液体-DMSO复合溶剂中的溶解性,并采用静置冷却法对TATB进行了重结晶,对重结晶后的TATB进行晶型观察、红外检测。结果表明,所选择的几种离子液体-DMSO的复合溶剂体系对TATB均有一定的溶解能力,其中丁磺酸甲基咪唑乙酸盐-DMSO对TATB的溶解能力最好,硝酸丁基三乙基季铵盐-DMSO对TATB的溶解效果最差。     

离子液体及其吸收机理的研究进展

介绍了近几年常用于吸收二氧化碳的几类离子液体,分别阐述了每种离子液体的特点,综述了国内外离子液体吸收二氧化碳的研究结果。对胺类离子液体吸收二氧化碳时的反应机理加以总结,分类介绍每种机理的特性。最后,针对离子液体现有的状况提出建议,并对未来的研究方向做了展望。     

离子液体水溶液临界胶束浓度的研究进展

离子液体作为表面活性剂或反应介质已引起人们的广泛关注。本文介绍了离子液体在水溶液中的自聚合行为,尤其是离子液体水溶液临界胶束浓度的确定。并介绍了几种不同确定离子液体水溶液的临界胶束浓度的方法。     

COSMO-RS:An ionic liquid prescreening tool for gas hydrate mitigation

Recently ionic liquids(ILs) are introduced as novel dual function gas hydrate inhibitors. However, no desired gas hydrate inhibition has been reported due to poor IL selection and/or tuning method. Trial error as well as selection based on existing literature are the methods currently employed for selecting and/or tuning ILs. These methods are probabilistic, time consuming, expensive and may not result in selecting high performance ILs for gas hydrate mitigation. In this work, COSMO-RS is considered as a prescreening tool of ILs for gas hydrate mitigation by predicting the hydrogen bonding energies(E_(HB)) of studied IL inhibitors and comparing the predicted E_(HB) to the depression temperature(?) and induction time. Results show that, predicted EHBand chain length of ILs strongly relate and significantly affect the gas hydrate inhibition depression temperature but correlate moderately(R = 0.70) with average induction time in literature. It is deduced from the results that, ? increases with increasing IL EHBand/or decreases with increasing chain length. However, the cation–anion pairing of ILs also affects IL gas hydrate inhibition performance. Furthermore, a visual and better understanding of IL/water behavior for gas hydrate inhibition in terms of hydrogen bond donor and acceptor interaction analysis is also presented by determining the sigma profile and sigma potential of studied IL cations and anions used for gas hydrate mitigation for easy IL selection.     

Facilitated-transport supported ionic liquid membranes for the simultaneous recovery of hydrogen and carbon monoxide from nitrogen-enriched gas mixtures

Off-gases with high content of carbon monoxide and hydrogen are often generated after a partial combustion of hydrocarbons in some industrial processes performed in reductive conditions. In these mixtures, both gases are usually accompanied by nitrogen. The selective recovery of these valuable compounds, H₂ and CO, employing an efficient membrane technology is sought as a means to reduce the environmental footprint of the industrial activity. In this respect, this work provides fundamental knowledge on the transport properties of H₂ through supported ionic liquid membranes (SILMs) prepared with an imidazolium-based room-temperature ionic liquid (RTIL) combined with either a chloride or a chlorocuprate(I) anion; this latter anion has already proved to enhance CO permeability across these SILMs due to a facilitated transport mechanism. Results showed that H₂ is more permeable than CO and N₂ through these RTILs due to its higher diffusivity. The H₂/N₂ and H₂/CO selectivities through the chloride-based RTIL are 11 and 6, respectively. However, when the RTIL with the chlorocuprate(I) anion is employed instead of the chloride anion, the H₂/N₂ selectivity does not change whereas the H₂/CO selectivity decreases, hence allowing obtaining a gas permeate stream with high content of both H₂ and CO, and very low content of N₂.     

Improved ionic conductivity of nitrile rubber/ionic liquid composites

Polymer electrolytes with high ionic conductivity and good elasticity were prepared by mixing nitrile rubber (poly(acrylonitrile-co-butadiene) rubber; NBR) with ionic liquid, N-ethylimidazolium bis(trifluoromethanesulfonyl)imide (EImTFSI). The NBR/EImTFSI composites were obtained as homogeneous and transparent films when the ionic liquid content was less than 60 wt%. Raman spectroscopy suggested the interaction between nitrile group of NBR and TFSI anion. Sample with ionic liquid content of 50 wt% showed the ionic conductivity of 1.2×10⁻⁵ S cm⁻¹ at 30 °C. Addition of lithium salt to this NBR/EImTFSI composite further enhanced the ionic conductivity to about 10⁻⁴ S cm⁻¹ without spoiling mechanical properties. DSC studies showed two glass transition temperatures for composites indicating microphase separation.     

Ionic liquids for acetylene and ethylene separation: Material selection and solubility investigation

Potential applications of ionic liquids (ILs) for the green separation process of acetylene in ethylene and for the storage of acetylene were investigated. To deal with this proposal, the solubilities of the unsaturated hydrocarbons in various ionic liquids were evaluated. The solubility of ethylene shows a solubility parameter-dependent behavior as indicated by the proportional relationship between the natural log value of Henry's law constant and the inverse molar volume of ILs. This correlation suggests the most important role of voids formation within IL to accommodate the solutes and the applicability of regular solution theory to model the solubility behavior. Whereas, in addition to the free-volume contribution of ILs, the solubility of acetylene is largely controlled by a specific solute–solvent interaction as a result from the association of the acidic hydrogen character in acetylene and the relative basicity of the anion. Those two different solubility behaviors result in a high absorption selectivity of acetylene over ethylene in the basic ILs. ¹H NMR experiment clearly demonstrated the presence of a substantial interaction between the acetylene and the anion of IL. Interestingly, this solute–solvent interaction is reversible as indicated by the absorption–desorption test of acetylene in [BMIM][Me₂PO₄].     

聚合离子液体的研究进展

随着对离子液体研究的深入,离子液聚合物IF成为新的研究热点.简单综述了近年来聚合离子液的合成方法,主要包括自由基引发聚合、辐射聚合以及与其他物质共聚等.其中,自由基引发聚合操作简便,易于监测,是目前制备聚合离子液体的常用方法.     

微波辅助离子液体液-液微萃取分析水溶性化妆品中防腐剂的含量

采用微波辅助离子液体分散液-液微萃取对水溶性化妆品中的对羟基苯甲酸酯类防腐剂进行预处理,并结合高效液相色谱-紫外检测对其分析。考察了离子液体用量、分散剂种类及用量、微波时间、萃取时间、离心时间和盐效应对离子液体微萃取效果的影响。在最佳实验条件下,3种酯的富集因数为68.3～124.5,标准曲线在0.1～50 mg/L呈线性相关,线性相关系数r>0.9989,相对标准偏差(RSD,n=3)为4.9%～5.1%。3种物质的检测限为0.6～1.2μg/L。     

New high permeable polysulfone/ionic liquid membrane for gas separation

In this study, the effects of 1-Ethyl-3-methylimidazolium tetrafluoroborate ionic liquid on CO₂/CH₄ separation performance of symmetric polysulfone membranes are investigated. Pure polysulfone membrane and ionic liquid-containing membranes are characterized. Field emission scanning electron microscopy (FE-SEM) is used to analyze surface morphology and thickness of the fabricated membranes. Energy dispersive spectroscopy (EDS) and elemental mapping, Fourier transform infrared (FTIR), thermal gravimetric (TGA), X-ray diffraction (XRD) and Tensile strength analyses are also conducted to characterize the prepared membranes. CO₂/CH₄ separation performance of the membranes are measured twice at 0.3 MPa and room temperature (25 °C). Permeability measurements confirm that increasing ionic liquid content in polymer-ionic liquid membranes leads to a growth in CO₂ permeation and CO₂/CH₄ selectivity due to high affinity of the ionic liquid to carbon dioxide. CO₂ permeation significantly increases from 4.3 Barrer (1 Barrer=10^-10 cm³(STP)·cm·cm^-2·s^-1·cmHg^-1, 1cmHg=1.333kPa) for the pure polymer membrane to 601.9 Barrer for the 30 wt% ionic liquid membrane. Also, selectivity of this membrane is improved from 8.2 to 25.8. mixed gas tests are implemented to investigate gases interaction. The results showed, the disruptive effect of CH₄ molecules for CO₂ permeation lead to selectivity decrement compare to pure gas test. The fabricated membranes with high ionic liquid content in this study are promising materials for industrial CO₂/CH₄ separation membranes.     

Solubility and diffusion coefficient of oxygen in 1-ethyl-1-methylpyrrolidinium fluorohydrogenate room temperature ionic liquid at 298–373 K

Solubility (C) and diffusion coefficient (D) of oxygen in 1-ethyl-1-methylpyrrolidinium fluorohydrogenate (EMPyr(FH)_1.7F) room temperature ionic liquid (RTIL) have been determined at 298–373 K by the combination of linear-sweep voltammetry and hydrodynamic chronocoulometry with a rotating disc electrode (RDE). The solubility was 0.409 mmol dm⁻³ at 298 K and decreased with an increase in temperature. The solubility was compared with other RTILs and the difference was explained by the free volume estimated from the observed molar volume and the calculated molar volume. The diffusion coefficient was 1.59 × 10⁻⁵ cm² s⁻¹ at 298 K. The activation energy of diffusion was estimated to be 24.5 kJ mol⁻¹ from the slope of the Arrhenius plot. The permeability of oxygen (C × D) was compared with those in other RTILs, 0.5 M H₂SO₄ aqueous solution and Nafion^® in water to discuss the oxygen cross-over in fuel cell application.     

Separation of light hydrocarbons with ionic liquids: A review

Light hydrocarbons(C_1–C_4) are fundamental raw materials in the petroleum and chemical industry. Separation and purification of structurally similar paraffin/olefin/alkyne mixtures are important for the production of highpurity or even polymer-grade light hydrocarbons. However, traditional methods such as cryogenic distillation and solvent absorption are energy-intensive and environmentally unfriendly processes. Ionic liquids(ILs) as a new alternative to organic solvents have been proposed as promising green media for light hydrocarbon separation due to their unique tunable structures and physicochemical properties resulting from the variations of the cations and anions such as low volatility, high thermal stability, large liquidus range, good miscibility with light hydrocarbons, excellent molecular recognition ability and adjustable hydrophylicity/hydrophobicity. In this review, the recent progresses on the light hydrocarbon separation using ILs are summarized, and some parameters of ILs that influence the separation performance are discussed.