Effect of methylimidazolium-based ionic liquids on vapor–liquid equilibrium behavior of tert-butyl alcohol + water azeotropic mixture at 101.3 kPa

Three ionic liquids(ILs),1-ethyl-3-methylimidazolium bromine([EMIM]Br),1-butyl-3-methylimidazolium bromine([BMIM]Br),and 1-hexyl-3-methylimidazolium bromine([HMIM]Br),were used as the solvent for separation of {tert-butyl alcohol(TBA)+ water} azeotrope.Vapor–liquid equilibrium(VLE)data for {TBA + water + IL}ternary systems were measured at 101.3 k Pa.The results indicate that all the three ILs produce an obvious effect on the VLE behavior of {TBA + water} system and eliminate the azeotropy in the whole concentration range.[EMIM]Br is the best solvent for the separation of {TBA + water} system by extractive distillation among the three ILs.The experimental VLE data for the ternary systems are correlated with the NRTL model equation with good correlations.Explanations are given with activity coefficients of water and TBA,and the experimental VLE-temperature data for {TBA or water + IL} binary systems.     

模板剂碳链长度对MCM-41晶体结构的影响

The mesoporous molecular sieve （MCM）-41 using ionic liquid as template has been prepared. The typical template of ionic liquid was [C16mim]X. In this article, the use of 1-alkyl-3-methylimidazolium （[Cnmim]Br, where n= 12,14,16,18,20） salts as templates in the synthesis of MCM-41 is reported. The results showed that the synthesized MCM-41 had uniform pore diameter, high surface area and stable framework. The largest surface area of MCM-41 was the one prepared with [C14mim]Br as template. When using [C18min]Br as template, the narrowest pore distribution sample was obtained and the effect of surface tension of template solution to MCM-41 was first discussed.     

Effects of imidazolium-based ionic liquids on the isobaric vapor–liquid equilibria of methanol + dimethyl carbonate azeotropic systems

The separation of methanol(MeOH) and dimethyl carbonate(DMC) is important but difficult due to the formation of an azeotropic mixture. In this work, isobaric vapor–liquid equilibrium(VLE) data for the ternary systems containing different imidazolium–based ionic liquids(ILs), i.e. MeOH + DMC + 1-butyl-3-methy-limidazolium bis[(trifluoromethyl)sulfonyl]imide([Bmim][Tf_2N]), MeOH + DMC + 1-ethyl-3-methyl-imidazolium bis[(trifluoromethyl)sulfonyl]imide([Emim][Tf_2N]), and MeOH + DMC + 1-ethyl-3-methylimidazolium hexafluorophosphate([Emim][PF6])) were measured at 101.3 kPa. The mole fraction of IL was varied from0.05 to 0.20. The experimental data were correlated with the NRTL and Wilson equations, respectively. The results show that imidazolium-based ILs were beneficial to improve the relative volatility of MeOH to DMC,and [Bmim][Tf_2 N] showed a much more excellent performance on the activity coefficient of MeOH. The interaction energies of system components were calculated using Gaussian program, and the effects of cation and anion on the separation coefficient of the azeotropic system were discussed.     

Measurement and modeling of vapor-liquid equilibrium for ternary system water + 2-propanol + 1-butyl-3-methylimidazoliumchloride简

Vapor-liquid equilibrium （VLE） data for water ＋ 2-propanol ＋ 1-butyl-3-methylimidazolium chloride （[bmim]Cl） were measured. Six sets of complete T, x, y data are reported, in which the 2-propanol mole fraction on IL-free basis is fixed separately at 0.1, 0.2, 0.4, 0.6, 0.8, and approximate 0.98, while the IL mass fraction is varied from 0.1 to 0.8, in an interval of 0.1. The non-random-two-liquid （NRTL） and electrolyte non-random-two-liquid （eNRTL） equations are used to correlate the experimental data with satisfactory results. The ternary VLE behavior is also modeled with the parameters obtained by correlating two data sets, in which the mole fraction of 2-propanol on IL-free basis is approximately 0.1 and 0.98. In this way, the six sets of data are reproduced satisfactorily. With the eNRTL model, the root-mean-square deviation for temperature is 0.82 K and that for vapor-phase mole fraction is 0.0078. The influences of IL on activity coefficients and relative volatility of the volatile components are also graphically illustrated.     

新型离子液体用于芳烃、烯烃与烷烃分离的初步研究

The separation of aromatic hydrocarbons or olefins from paraffins is very important in chemical industry. The volatile organic solvents used are usually harmful to environment and human health. As green solvents, room temperature ionic liquids are potential substitutes for the separation of hydrocarbon products. Activity coefficients at infinite dilution of hydrocarbon solutes, such as alkanes, hexenes,alkylbenzenes and styrene, in 1-butyl-3-methyl imidazolium hexafluorophosphate ( [BMIM] [PF6]), 1-allyl-3-methylimidazolium tetrafluoroborate ( [AMIM] [BF4] ), 1-isobutenyl-3-methylimidazolium tetrafluoroborate ( [MPMIM] [BF4]) and [MPMIM] [BF4] AgBF4 were determined by gas-liquid chromatography. The measurements were carried out at different temperatures between 298.15 K and 318. 15 K. The separation effects of these ionic liquids for olefin/paraffin, alkanes/benzene and hexene isomers were discussed.     

Removal of mercaptans from light oils using ionic liquid–NaOH aqueous solution as extractants

The application of ionic liquids as alternatives to conventional organic solvents in the extraction process has been investigated. In the present study, fourteen species of imidazolium-based ionic liquids were added into the Na OH(aq) to remove the mercaptans. The influences of anion species and cation alkyl chain length of the imidazolium-based ionic liquids on the performance of mercaptan removal from light oils have been discussed.The efficiency of extraction for mercaptans exhibited the order of [Ac]~-N [OH]~-≈ [Br]~-N [BF4]~-. The longer alkyl chain imidazolium-based ionic liquids contributed to enhance desulfurization rate of 1-butyl mercaptan.100% desulfurization rate of 1-butyl mercaptan was achieved by the anion of Ac-ionic liquids and Na OH(aq)at a volume ratio of 40:1(V(oil):V(ionic liquid)) and a short equilibrium time within 10 min.     

Dissolution of antibiotics mycelium in ionic liquids: Performance and mechanism

Antibiotics mycelium, byproduct of pharmaceutical industry, contains high percentage of proteins, polysaccharides and lipids, while, the low solubility in traditional solvents limits its utilization. The dissolution process of penicillin mycelium was investigated using ionic liquids(ILs) as solvent. Quantitative correlation of solubility and ILs structure and dissolution mechanism were determined. About 91.45% of penicillin mycelium was dissolved in 1-butyl-3-methylimidazolium acetate([Bmim]Ac) under the condition of 120.0 ℃ and [Bmim]Ac/mycelium(m/m) ratio of 3.90:1. Synergistic effect of ILs and DMSO was confirmed with the DMSO/[Bmim]Ac(v/m) ratio in the range of 0.0-1.0. At 25.0 ℃, the dissolution of penicillin mycelium increased from 69.74% to94.50%, with the ratio of DMSO to [Bmim]Ac(v/m) as 1:1. The room temperature dissolution of mycelium provides a novel and energy-saving process for its high-valued utilization. The NMR and FT-IR spectra showed that hydrogen bonds are the dominant driving force for the dissolution in ILs. Quantitative study on the effects of anions and cations of ILs on dissolution using Kamlet-Taft model showed that there was a linearly positive correlation between solubility of penicillin mycelium and(3 parameter of the ILs. The solubility of mycelium increased with increasing hydrogen bond accepting ability of anions and donating ability of cations.     

Molecular Simulation on Microstructure of Ionic Liquids in Capture of CO_2

Molecular dynamic simulation is used to study the microstructure of four kinds of ionic liquids (ILs), [Emim]PF6, [Emim][Tf2N], [PC6,6,6,14]PF6 and [PC6,6,6,14][Tf2N] in the capture process of CO2. Radial distribution function (RDF) and spatial distribution function (SDF) are used to analyze the microscopic properties of these systems. The calculated results show that the space distribution of CO2 around ILs determines the capability of ionic liquids for capturing CO2. Based on the analysis of SDF, CO2 and PF6- are overlapped partially around [Emim]+ in [Emim]PF6-CO2 mixture. When the anion is [Tf2N]-, cations are mainly distributed on one side of [Tf2N]- near N atom, and CO2 is concentrated on two sides near the fluoroalkylgroup (?CF3), and there is little overlapped district between cation and CO2. In [PC6,6,6,14]PF6-CO2 mixture, layered structure is found and CO2 is much nearer to PF6- than [PC6,6,6,14]+. Based on the analysis of RDF, in the phosphonium-based ILs, the highest distribution densities of anions and CO2 around cations are about 6 and 3 times as their average ones respectively, while in the imidazolium-based ILs, they are about 3 and 2 respectively, this means that the distributions of CO2 and anions around the imidazolium-based ILs are more evenly distributed than those around the phosphonium-based ILs.     

乙腈+[C4mim][Cl]、乙腈+[C4mim][BF4]、乙腈+[C6mim][Cl]的气液平衡测定与关联（英文）

Vapor pressures were measured for acetonitrile+1-butyl-3-methylimidazolium chloride ([C4mim][Cl]),+1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim][BF4]) and+1-hexyl-3-methylimidazolium chloride ([C6mim][Cl]) at temperatures of 313 to 353 K by a quasi-static method. The experimental data for the binary sys-tems were correlated by the non-random two liquid (NRTL) equation with an average absolute relative deviation (AARD) of within 1.84%. The results indicate that the three ionic liquids (ILs) can result in a negative deviation from the Raoult's law for the binary solutions containing acetonitrile, and the affinity between ILs and acetonitrile mole-cules fol ows the order [C4mim][BF4]+acetonitrile N [C4mim][Cl]+acetonitrile N [C6mim][Cl]+acetonitrile.     

离子液体1-乙基-3-甲基咪唑醋酸盐对酿酒酵母AY93161的毒性及其酒精发酵过程的影响

为了考察离子液体在由木质纤维原料制备可发酵糖中的残留对后续酒精发酵过程的影响,对离子液体1-乙基-3-甲基咪唑醋酸盐([Emim]Ac)对酿酒酵母AY93161的毒性及其酒精发酵过程的影响进行研究。通过亚甲基蓝染色,利用OLYMPUS CX41显微镜观察不同[Emim]Ac浓度下对数生长期酵母细胞的形态结构,出芽情况及代谢活性,发现在[Emim]Ac浓度高于5 g·L^-1时,酵母细胞的形态结构会发生变化,在[Emim]Ac浓度高于0.1 g·L^-1时,随着[Emim]Ac浓度的增加,酵母的出芽速率及代谢活性降低。通过平板培养和液体悬浮培养测得[Emim]Ac对酵母的半有效浓度EC50和半抑制浓度IC50分别为4.45、7.70 g·L^-1。通过测定不同[Emim]Ac浓度下酵母酒精发酵的过程数据,发现在[Emim]Ac浓度低于0.1 g·L^-1时,对酵母酒精发酵过程几乎无影响,在[Emim]Ac浓度高于0.1 g·L^-1时,对酵母酒精发酵有抑制作用,[Emim]Ac对酵母酒精发酵的抑制作用主要是由其对菌体生长的抑制所致。     

以功能化离子液体为溶剂的多酸脱硫性能

合成了5种功能化离子液体（[CPL][TBAB],[CPL]BF₄,[Bmim]HCO₃,[Bmim]OAc和[Bmim]Im）以及含有相同阳离子的多酸离子液体[CPL]₃PMo₁₂O₄₀和[Bmim]₃PMo₁₂O₄₀,构建了以功能化离子液体为溶剂的多酸液相氧化脱硫体系,优选出最佳脱硫剂,并考察了不同吸收温度、气体流量下最优脱硫剂的脱硫性能。结果表明[Bmim]₃PMo₁₂O₄₀-[Bmim]HCO₃脱硫效率最高,优化的吸收条件为温度高于40℃、气体流量为100 ml·min^-1;[Bmim]₃PMo₁₂O₄₀-[Bmim]HCO₃可以简单地用空气再生。     

[NH2-emim]Br/[Bmim]BF4离子液体中二氧化碳的电化学还原

以2-溴乙胺氢溴酸和N-甲基咪唑盐为原料合成了氨基功能化离子液体1-（2-胺乙基）-3-甲基咪唑溴盐（[NH₂-emim]Br）,用¹H NMR和IR对所制备的离子液体进行了表征,测得25℃下[NH₂-emim]Br的黏度26.691 Pa·s、电导率0.1130 mS·cm^-1,CO₂的溶解饱和度82%（摩尔分数）,将不同含量的[NH₂-emim]Br与[Emim]BF₄、[Bmim]BF₄、[Bmim]PF₆组成二元复合离子液体,并用于CO₂电化学还原研究,循环伏安研究表明,CO₂在[NH₂-emim]Br（0.5%）-[Bmim]BF₄复合离子液体中的还原峰电位较[Bmim]BF₄正移0.4 V,还原峰电流增大9倍,黏度降低为0.08227 Pa·s,电导率增大至1.317 mS·cm^-1,是一种较好的CO₂电化学还原离子液体体系。     

Vapor pressure measurement and correlation of acetonitrile+1-butyl-3-methylimidazolium chloride,+1-butyl-3-methylimidazolium tetrafluoroborate,and+1-hexyl-3-methylimidazolium chloride

Vapor pressures were measured for acetonitrile+1-butyl-3-methylimidazolium chloride ([C4mim][Cl]),+1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim][BF4]) and+1-hexyl-3-methylimidazolium chloride ...     

2,6-二甲氧基苯酚在1-丁基-3-甲基咪唑四氟硼酸盐水溶液中溶解行为的红外光谱分析

利用衰减全反射红外光谱(ATR-IR)和二维相关红外技术研究2, 6-二甲氧基苯酚(2, 6-DMP)在1-丁基-3-甲基咪唑四氟硼酸盐([C₄mim]BF₄)水溶液(离子液体摩尔分数x_IL=1.0～0.02)中的溶解行为。随着水量增大, 2, 6-DMP溶解度先增大而后急剧减小, 对应的x_IL阈值为0.1。2, 6-DMP与[C₄mim]BF₄之间存在强相互作用, 2, 6-DMP上的甲氧基是重要作用位点之一;当少量的水加入[C₄mim]BF₄(x_IL=0.1～1.0), 致密的离子簇结构被解离, 2, 6-DMP容易与[C₄mim]BF₄作用, 溶解度增大;随着大量水加入(0.02IL<0.1), 离子簇完全解离为大分子水簇包围的离子对, 憎水的2, 6-DMP与[C₄mim]BF₄作用困难, 溶解度减小。这种由于水量改变引起的[C₄mim]BF₄水溶液微观结构变化影响2, 6-DMP溶解行为。     

High capacity absorption of SO2 using imidazole ionic liquid mixtures

The capture of sulfur dioxide (SO₂) with readily available and cost-effective ionic liquids (ILs) is one of the challenges for the application of ILs. Here, we synthesized the ILs mixtures with different molar ratios (3∶1, 2∶1, 1∶1, 1∶2, and 3∶1) of 1-ethyl-3-methylimidazolium chloride ([Emim][Cl]) and 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]) to study their SO₂ absorption capacities. The SO₂ solubilities in these mixtures were investigated under different conditions. The SO₂ absorption capacities of [Emim][Cl]_x[OAc]_1-x at different temperatures and SO₂ partial pressure were measured. The results show that ILs can effectively capture SO₂. There exists a synergistic promotion effect between [Emim][Cl] and [Emim][OAc], resulting in quite high SO₂ absorption capacity. The [Emim][Cl]_0.33[OAc]_0.66 mixture can capture SO₂ (1.34±0.08) and (0.74±0.05) g/g at 1.0 and 0.2 atm(1 atm=101325 Pa), respectively. Comparing with the reported data, [Emim][Cl]_x[OAc]_1-x mixtures show obvious advantage for SO₂ capture. In addition, these ionic liquid mixtures have good reversibility for the absorption and desorption of sulfur dioxide.     

咪唑类离子液体混合物用于二氧化硫高效吸收

开发易制备、价格便宜、面向SO₂气体高效分离的离子液体（ILs），是当前ILs从实验探索迈向工业应用的难点与重大挑战。合成了不同摩尔比（3∶1、2∶1、1∶1、1∶2和1∶3）的1-乙基-3-甲基咪唑氯盐（[Emim][Cl]）和1-乙基-3-甲基咪唑乙酸盐（[Emim][OAc]）的离子液体混合物[Emim][Cl]_x[OAc]_1-x， 在测定其密度、黏度、热稳定性等基本物性数据的基础上，研究了[Emim][Cl]_x[OAc]_1-x混合物在不同温度和SO₂分压下的SO₂吸收能力。结果表明，[Emim][Cl]_x[OAc]_1-x能够有效地捕获SO₂。[Emim][Cl]与[Emim][OAc]之间存在协同促进作用，有利于实现SO₂高效吸收。[Emim][Cl]_0.33[OAc]_0.66混合液在1.0和0.2 atm（1 atm=101325 Pa）下捕获SO₂量分别为（1.34±0.08）和（0.74±0.05） g/g，与现有结果相比，混合物在SO₂捕获方面有明显优势。此外，这些离子液体混合物对二氧化硫的吸收和解吸具有良好的可逆性。     

[Bmim][BF4]/MEA混合水溶液的CO2汽液平衡和解吸能耗分析

搭建汽液平衡实验台,对液液分相CO₂吸收剂1-丁基-3-甲基咪唑四氟硼酸盐（[Bmim][BF₄]）/乙醇胺（MEA）混合水溶液与CO₂的汽液平衡进行了实验测量与分析,并对该吸收剂解吸能耗进行计算。结果表明,随着温度的升高,相同担载量溶液对应的CO₂分压升高,[Bmim][BF₄]质量分数的改变对汽液平衡的影响不明显。与传统有机胺溶液30%（质量）MEA相比,该吸收剂在能耗方面主要优势在于解吸过程中显热和潜热的减小。其反应热在担载量大于0.45之后明显减小,潜热的减小主要由于解吸塔内H₂O气相分压和摩尔分数的减小,当[Bmim][BF₄]质量分数大于30%时,显热可以减少30%以上,减少的原因主要为比热容的降低和富液胺浓度的提升。     

Modified g-C3N4 derived from ionic liquid and urea for promoting visible-light photodegradation of organic pollutants

In this work, modified g-C₃N₄ was fabricated successfully by calcination of ionic liquid (IL) and urea. The addition of IL changed the polymerization mode of urea, induced the self-assembly of urea molecules, modified the morphological structure of the tightly packed g-C₃N₄, and extended the electron conjugation system. When using 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) as a modifier, the heteroatom Cl could be inserted into the g-C₃N₄ to optimize the electronic structure. The results of characterizations indicate that the unique structure of modified g-C₃N₄ has an expanded electron delocalization range, introduces an interlayer charge transmission channel, promotes the charge transmission, reduces the band gap, enhances the absorption of visible light, and inhibits electron-hole recombination. Modified g-C₃N₄ showed excellent photocatalytic performance for the degradation of rhodamine B and tetracycline. Furthermore, the effect of different anions in 1-butyl-3-methylimidazolium salts ([Bmim]Cl, [Bmim]Br, [Bmim][BF₄], and [Bmim][PF₆]) on the structure and function of g-C₃N₄ are discussed.     

离子液体对溶菌酶晶体形态和活性的影响

以鸡蛋清溶菌酶为模型蛋白,采用冷却结晶法结晶以及浊度法测定酶活性,研究了分别添加4种亲水性离子液体(1-丁基-3-甲基咪唑四氟硼酸盐([C₄mim]BF₄)、1-丁基-3-甲基咪唑氯盐([C₄mim]Cl)、1-丁基-3-甲基咪唑溴盐([C₄mim]Br)和1,3-二甲基咪唑碘化物([dmim]I))条件下溶菌酶晶体形态和晶体活性的变化。利用光学显微镜对溶菌酶结晶过程的晶体形态进行分析,结果表明添加离子液体会影响溶菌酶的晶体形态和尺寸。离子液体[C₄mim]BF₄介导的溶菌酶形成棒状晶体。与未添加离子液体相比,[C₄mim]Cl和[C₄mim]Br均未改变溶菌酶晶体形态,均呈块状晶体,但[C₄mim]Cl和[C₄mim]Br促进溶菌酶晶体生长,晶体尺度均增加。而添加[dmim]I,溶菌酶呈现针状晶体。采用浊度法测定溶菌酶晶体活性,结果表明不同的离子液体对溶菌酶晶体的活性...     

离子液体混合溶剂预处理后孟宗竹的热解

使用1-丁基-3-甲基咪唑氯化盐([Bmim]Cl)、1-丁基-3-甲基咪唑四氟硼酸盐([Bmim]BF₄)和1-丁基-1-甲基吡咯烷氯化物([Bmpy]Cl)与水并添加固体酸催化剂Nafion^®NR50组成的混合溶剂对孟宗竹进行预处理比较研究,分析了处理后孟宗竹的成分含有量、结晶结构和表面形貌等变化。把处理后的孟宗竹应用于热解研究中,通过TG-DTA和GC-TCD的分析,发现[Bmim]Cl离子液体的混合溶剂处理后的孟宗竹更易于热解反应;此外热解产物更多地从焦炭转化成气体产物;其中添加固体酸的混合溶剂预处理后的1.0 g孟宗竹样品中,在热解反应后焦炭含量为0.19 g,低于未处理样品的0.24 g;生成约0.12 g气体产物大于未处理样品的0.04 g。并探讨了离子液体混合溶剂作为一种新型前处理溶剂应用于生物质热解研究中的潜力和问题。