咪唑离子液体氯化物水溶液的密度、折光率和体积性质

常压下,测定了咪唑离子液体氯化物([C_2mim]Cl、[C_4mim]Cl、[C_6mim]Cl、[C_8mim]Cl)与水的二元混合溶液在288.15K、298.15K、308.15K下的密度和折光率,计算获得了过量摩尔体积和折光率偏差,并用Redlich-Kister方程对衍生性质数据进行拟合,通过过量摩尔体积研究了二元混合溶液中离子液体与水分子之间的相互作用,同时采用多项式方程对二元混合溶液的密度及折光率随组成的变化进行了拟合。结果表明,二元混合溶液的密度和折光率随离子液体质量分数的增加而增大,随离子液体阳离子烷基链的增长、温度的升高而减小;二元混合溶液的过量摩尔体积为负值而折光率偏差为正值;离子液体与水分子之间具有较强的相互作用。     

离子液体在银杏叶黄酮分离纯化中的应用

目的:本文就银杏叶中银杏黄酮的分离纯化进行研究,建立了离子液体/盐双水相体系分离纯化银杏黄酮的新方法,为银杏黄酮的开发应用提供了科学依据。方法:将银杏叶进行粗提取,测定其黄酮总量。应用溴化1-辛基-3-甲基咪唑[C_8mim]BF_4和溴化1-丁基-3-甲基咪唑[C_4mim]BF_4分别与(NH_4)_2SO_4组成的双水相体系纯化银杏黄酮,探讨离子液体与盐浓度、体系温度对银杏黄酮萃取效率的影响。结果:以槲皮素作对照品用高效液相定性测定,发现离子液体并没有改变银杏黄酮的化学结构。结论:离子液体双水相体系实现了对银杏黄酮粗提取物的分离、纯化。     

一个物理化学设计实验的探讨与改进——离子液体溶液平均活度系数的测定

文章制备了溴化1-十二烷基-3-甲基咪唑[C12mim]Br和1-十二烷基-3-甲基咪唑四氟硼酸盐[C12mim][BF4]两种离子液体。在不同温度下,测定了两种离子液体水溶液的电导率,根据电导率-浓度曲线转折点求出了两种离子液体水溶液的临界胶束浓度。由Debye-Hücker和Osager-Falk-enhangen公式计算出离子液体的平均活度系数。结果表明：[C12mim]Br和[C12mim][BF4]的水溶液临界胶束分别为5.75×10-3 mol·L-1和6.00×10？3 mol·L-1。25℃下,平均活度系数随浓度的增大而降低。     

甲基咪唑胺类离子液体的合成及其对ATRP反应的影响

以N-甲基咪唑为骨架引入1,2-二氯乙烷合成中间体氯化1-氯乙基-3-甲基咪唑([CeMIM]Cl),再与1,3-丙二胺反应合成了氯化1-(丙基氨基)乙基-3-甲基咪唑离子液体([N_2C_3MIM]Cl)。通过FT-IR、1 H NMR对[N_2C_3MIM]Cl进行分析测试,确证了其化学结构。通过循环伏安法测得[N_2C_3MIM]Cl具有较低的氧化还原电势,为-0.522V,与有机配体相比[N_2C_3MIM]Cl具有较好的配位性能。将[N2C3MIM]Cl与CuBr配位用于催化甲基丙烯酸甲酯(MMA)的原子转移自由基聚合(ATRP)反应,经凝胶渗透色谱法(GPC)测试证明[N_2C_3MIM]Cl对ATRP反应具有较好的可控性。原子吸收光谱测定聚合产物PMMA中Cu~(2+)的残留量仅为270mg·kg~(-1),表明与传统有机配体相比,[N_2C_3MIM]Cl有利于催化剂与聚合产物的分离。     

磁性离子液体1-甲基-3-烷基咪唑四卤化铁盐的合成及其物性表征

合成了4种1-甲基-3-烷基咪唑四氯化铁盐[Cnmim]FeCl4(n=2, 4, 6, 8)及3种1-甲基-3-丁基咪唑四卤化铁([C4mim]FeX4, X=Cl, Br)磁性离子液体,光谱结果表明,[Cnmim]FeCl4及[C4mim]FeBr4中阴离子单一,而[C4mim]FeClBr3及[C4mim]FeCl3Br中的阴离子为FeBr4-, FeBr3Cl-, FeCl2Br2-, FeCl3Br-, FeCl4-的混合物. 测定了其密度、粘度、电导率,磁性离子液体密度较大,25℃时为1.25~1.94 g/cm3;粘度较小,25℃时为21~65 mPa×s;电导率较大,30℃时为0.23~1.37 S/m. 并研究了其物性随温度及结构的变化规律.     

1，3-二烷基咪唑类离子液体的合成研究

通过N-烷基化反应制备了中间产物氯化-1-丁基-3-甲基咪唑[BMIM]Cl离子液体,得到较佳的制备条件。引入微波辅助改进了[BMIM]Cl合成方法。同时在超声波辅助下,通过离子交换制备了亲水性离子液体1-丁基-3-甲基咪唑四氟硼酸盐[BMIM]BF4以及憎水性离子液体1-丁基-3-甲基咪唑六氟磷酸盐[BMIM]PF6。结果发现,微波辅助和超声波辅助可以加速反应速度。产物结构用IR和1H NMR进行表征。     

溶析结晶法在离子液体[ C5mim][OAc]合成中的应用

研究了用溶析结晶法辅助合成一种新型的碱性离子液体:1-甲基-3-戊基咪唑醋酸盐([C5mim] [OAc]),并通过1HNMR进行了表征.合成[c5mim][ OAc]所需中间体溴代1-甲基-3-戊基咪唑[C5mim][ Br],因其凝固点很低给重结晶纯化带来了难度.基于这一点,本文提出了用二次去离子水作为析出剂进行离...     

离子液体[AMIM]Cl的合成及对木质素的溶解性研究

本文研究了离子液体1-烯丙基-3-甲基咪唑氯盐([AMIM]Cl)的合成,考察了反应时间、反应温度、原料配比对[AMIM]Cl收率的影响,确定最佳反应时间为8h,最佳反应温度为80℃,原料氯丙烯与1-甲基咪唑最佳物质的量比为1∶3。另外,考察了[AMIM]Cl对木质素的溶解性能,确定80℃时木质素在离子液体[AMIM]Cl中的溶解度为最佳。     

离子液体催化2-氯噻吩氯甲基化反应研究

以2-氯噻吩、多聚甲醛为原料,以离子液体[C2mim]Br、[C3mim]Br、[C4mim]Br、[C5mim]Br、[C6mim]Br、[C7mim]Br、[C8mim]Br、[C12mim]Br、[Bmim]PF6、[Bmim]BF4、[Bmim]C4F9SO3和[Bmim]Cl为催化剂进行氯甲基化反应,得到产物2-氯-3-氯甲基噻吩。研究表明,离子液体可以促进2-氯噻吩的氯甲基化反应,具有相转移催化剂的效果,并且以[C4mim]Br和[C8mim]Br的催化效果为佳。反应最佳条件为:离子液体[C8mim]Br摩尔分数为5%(相对于2-氯噻吩),温度40℃,反应时间8h,产物产率可达92.1%。     

负载硅离子液体的合成及其催化性能

首先合成了氯代1-(2-羟乙基)-3-甲基咪唑离子液体[He MIM]Cl、溴代1-乙胺基-3-甲基咪唑离子液体[Ae MIM]Br和氯代1-羧乙基-3-甲基咪唑离子液体[Ce MIM]Cl 3种功能化咪唑离子液体,然后将这3种离子液体分别与正硅酸乙酯通过溶胶凝胶法制备了3种负载硅型离子液体[He MIM]Cl-Si、[Ae MIM]Br-Si和[Ce MIM]Cl-Si,并利用红外与XRD对其化学结构与结晶结构进行测定。再利用制备的离子液体催化环氧乙烷与二氧化碳合成碳酸乙烯酯。结果表明,离子液体负载硅后其催化性能明显提高,在较温和的条件下即可高效完成催化过程,且无聚酯或聚醚等副产物生成。其中,[Ce MIM]Cl-Si催化性能最好,在110℃、1.6 MPa催化条件下得到的转化率为99.2%,选择性为96.4%,产率为97.6%。     

离子液体复合催化剂催化松节油聚合反应的研究

用三氯化铝、三氯化锑与卤化1-烷基-3-甲基咪唑盐〔[Cnm im]X〕制备了3种酸性离子液体复合催化剂{[C2m im]B r-A lC l3/SbC l3、[C4m im]C l-A lC l3/SbC l3和[C8m im]C l-A lC l3/SbC l3},并用于催化松节油聚合反应,结果表明,以[C4m im]C l-A lC l3/SbC l3的催化活性为佳。以[C4m im]C l-A lC l3/SbC l3为催化剂,考察了m(松节油)∶m(甲苯)∶m{[C4m im]C l}∶m(A lC l3)∶m(SbC l3),反应温度和反应时间等条件对反应结果的影响。在m(松节油)∶m(甲苯)∶m{[C4m im]C l}∶m(A lC l3)∶m(SbC l3)=15∶15∶2∶3∶1.5,反应温度-10℃,反应时间4~5 h较佳工艺条件下,固体树脂产物的收率为64%,软化点为104℃。     

离子液体改性无机材料制备橡胶导热助剂

通过研究[C4mim]Br、[C7mim]Br、[C8mim]Br、[BPy]Br共4种离子液体对白炭黑、膨润土、高岭土、硅藻土、珍珠岩（深、浅色）共6种不同无机材料进行改性,并对改性前后的无机材料进行了FT-IR、TG和氮气吸附-脱附比表面积分析。应用改性后的无机材料与橡胶混炼制胶,测定其导热系数。结果表明,无机材料经离子液体改性后均比未改性的导热系数有所提高,其中,[C4mim]Br改性无机材料的导热系数提高幅度最大,[C4mim]Br改性的高岭土的导热系数高达0.389W/(m?K),与改性前的导热系数相比提高了89.76%。     

蒙脱土负载［C14mim］+有机阳离子催化合成柠檬酸三丁酯

通过咪唑基离子液体和蒙脱土在甲苯溶液中的离子交换反应，将热稳定性高的咪唑基有机阳离子［C₁₄mim］⁺交换吸附进入蒙脱土片层间，制备了蒙脱土负载的有机阳离子固体催化剂［C₁₄mim］⁺/MMT。利用XRD和TGA对催化剂的结构与性能进行了表征和测定，研究了蒙脱土负载有机阳离子固体催化剂的催化性能，初步考察了其稳定性及再次使用效率。研究结果表明，［C₁₄mim］⁺/MMT在合成无毒增塑剂柠檬酸三丁酯的酯化反应中表现出较高的催化活性，可循环使用。与未负载的C₁₄mimBF₄相比，［C₁₄mim］⁺/MMT具有催化活性高、稳定性好和易分离的特点。     

Raman Microscopic Study of Japanese Beech (Fagus crenata) As Treated with the Ionic Liquid, 1-Ethyl-3-Methylimidazolium Chloride

The chemical changes in various morphological regions of Japanese beech (Fagus crenata) upon treatment with the ionic liquid 1-ethyl-3-methylimidazolium chloride ([C2mim][Cl]), which preferentially dissolves cellulose, have been investigated by Raman microscopy. The reactivity of polysaccharides and lignin with [C2mim][Cl] differed depending on the types of wood tissues. Chemical components in parenchyma cells showed higher resistance to degradation upon [C2mim][Cl] treatment than wood fiber and vessel. In addition, the lignin structure was partially degraded or modified by [C2mim][Cl] treatment, and its binding mode was complicated; nevertheless, lignin was stable in [C2mim][Cl].     

Electrical conductivities for four ternary electrolyte aqueous solutions with one or two ionic liquid components at ambient temperatures and pressure

Thiswork provides amethod to explore the transport property of the electrolyte aqueous solutionswith one or two ionic liquids, especially focus on their electrical conductivity. The conductivities were measured for the ternary systems NaCl–[C₆mim][Cl] (1-hexyl-3-methylimidazolium chloride)–H₂O, [C₆mim][BF₄]–[C₆mim][Cl]–H₂O, NaNO₃–[C₆mim][BF₄](1-hexyl-3-methylimidazolium tetrafluoroborate)–H₂O, and [C₄mim][BF₄] (1-butyl-3- methylimidazolium tetrafluoroborate)–[C₆mim][BF₄]–H₂O, and their binary subsystems NaNO₃–H₂O, NaCl–H₂O, [C₆mim][BF₄]–H₂O, [C₆mim][Cl]–H₂O, and [C₄mim][BF₄]–H₂O, respectively. The conductivities of the ternary systems were also determined using generalized Young's rule and semi-ideal solution theory in terms of the data of their binary solutions. The comparison showed that the two simple equations provide good predictions for conductivity of mixed electrolyte solutions and the mixed ionic liquid solutions based on the conductivity of their binary subsystems.     

Separation of methyl linolenate and its analogues by functional mixture of imidazolium based ionic liquid-organic solvent-cuprous salt

Methyl linolenate was separated from its analogues by a new extraction system constructed by solvent,imidazolium based ionic liquids and cuprous salt. Firstly, the effect of ionic liquid on the dissolution of CuCl in acetonitrile, N,N-dimethylformamide(DMF), methanol and water was evaluated by visual observation. [C_4Mim][Cl]can improve the dissolution of CuCl in acetonitrile. Then, for the new system as acetonitrile-ILs-CuCl, extraction equilibrium, distribution ratio and selectivity of methyl linolenate and its analogues were determined by gas chromatography analysis and the mass balance. The extraction time, IL structures and CuCl concentrations were investigated. Distribution ratio decreased slightly, but selectivity increased significantly with the addition of CuCl, [C_4Mim][Cl] or [C_4Vim][NTF_2] into acetonitrile. [C_4Vim][NTF_2] had higher selectivity than [C_4Mim][Cl].But the selectivity of the system combining CuCl with [C_4Vim][NTF_2] was much lower than with [C_4 Mim][Cl].For the CuCl-[C_4Mim][Cl]-acetonitrile, the extraction efficiency was better than CuCl-acetonitrile, increasing Cu~+ concentration effectively improved the separation selectivity when ratio of CuCl/[C_4Mim][Cl] was less than 1. Compared with previous aqueous AgNO_3 extractions, the method of using CuCl is a much cheaper and practical way to enrich unsaturated fatty acid.     

Study on Dissolution and Regeneration of Poplar Wood in Imidazolium-Based Ionic Liquids

Abstract

We tested dissolution and regeneration of poplar wood using 1-butyl-3-methylimidazolium chloride ([C₄mim]Cl) and 1-butyl-3-methylimidazolium acetate ([C₄mim]OAc). When 5wt% of poplar sawdust in [C₄mim]OAc was stirred at 130°C, 96wt% of added poplar was dissolved in [C₄mim]OAc, whereas 25.3wt% of poplar dissolved in [C₄mim]Cl at the same reaction condition. Fourier transform infrared spectroscopy (FT-IR) and lignin content analysis revealed that poplar was partially delignified during the dissolution and regeneration processes. X-ray diffraction (XRD), thermal gravimetric analysis (TGA), and microscopy were used to characterize raw poplar sawdust, undissolved poplar, and regenerated wood from the poplar-ionic liquid solution. The direct acetylation of poplar-[C₄mim]OAc solution using acetyl chloride was also performed in the absence of any organic solvent. FT-IR analysis of the resulting wood sample revealed the formation of partially delignified acetylated-poplar.     

Deep Desulfurization of Gasoline Fuel using FeCl3-Containing Lewis-Acidic Ionic Liquids

The FeCl₃-containing Lewis-acidic ionic liquids (ILs) [C₆mim]Cl/FeCl₃(1:1.5), [C₆mim]Cl/FeCl₃(1:2), [C₈mim]Cl/FeCl₃(1:1.5), and [C₈mim]Cl/FeCl₃(1:2) were used as extractants for desulfurization of model fuel and gasoline fuel, respectively. The results demonstrate that these ILs are effective for the removal of sulfur compounds from model fuel under different mass ratio of IL to model fuel (1:1, 1:3, 1:5, 1:10) at 25°C. The extractive performance of ILs increased as the molar ratio of FeCl₃ to [C_nmim]Cl(n = 6, 8) varied from 1:1 to 1:2. The selectivity of sulfur compounds by extraction process followed the order of dibenzothiophene (DBT)>benzothiophene (BT) > 4,6-dimethyldibenzothiophene (4,6-DMDBT). The sulfur removal of gasoline fuel containing sulfur content of 440.3 ppmw could be up to 85.8%; that is to say that the sulfur content of gasoline fuel varied from 440.3 ppmw to 62.4 ppmw after one extraction stage. Moreover, the [C₆mim]Cl/FeCl₃(1:2) can be recycled for at least 4 times with a little decrease in the desulfurization activity.