咪唑类含能离子液体的合成及性能研究

以N-甲基咪唑、1,2-二甲基咪唑和2-氯乙醇为原料,经季铵化、硝化和复分解反应,合成了一系列咪唑类含能离子液体.通过紫外可见光谱、红外光谱、质谱、核磁共振和元素分析等对结构进行了表征.研究了其在常用有机溶剂中的溶解性,结果表明所合成的咪唑类含能离子液体在极性溶剂中具有良好的溶解性.采用热重分析法和差示扫描量热法研究了其热性能,结果表明所合成的含能离子液体具有良好的热稳定性,其中N-硝酰氧乙基咪唑硝酸盐的分解温度均在160℃左右,而N-羟乙基咪唑离子盐的分解温度均超过了190℃.差示扫描量热技术(DSC)实验表明,1-(2-硝酰氧乙基)-3-甲基咪唑硝酸盐和N-羟乙基咪唑类离子盐在二次升温过程中均发生了玻璃化转变,表现出了离子液体的特有性质.采用Kamlet-Jacobs方程估算了合成的含能离子液体的爆速和爆压等爆轰参数.     

1-丁腈-3-甲基咪唑双三氟甲基磺酸亚胺的性质

制备了功能化离子液体1-丁腈-3-甲基咪唑双三氟甲基磺酸亚胺。在T为283.15-353.15 K温度范围内,测定了该功能化离子液体的密度、动力粘度、电导率及折光率。讨论了亚甲基的增减对该类功能化离子液体的密度、动力粘度、电导率及折光率等性质的影响,并与传统咪唑类、吡啶类离子液体物理化学性质的变化趋势进行了对比。通过经验方程计算了该功能化离子液体的热膨胀系数、分子体积、标准摩尔熵及晶格能等热力学性质参数。讨论了Vogel-Fulcher-Tamman (VFT)方程和Arrhenius方程的适用性,得出VFT方程适用于该功能化离子液体,而Arrhenius方程并不适用。有关研究对新型离子液体的合成及其工业化的应用具有十分重要的意义。     

微波辐照合成羟基功能化离子液体氯盐中间体

采用微波辐照法合成了4种羟基功能化离子液体中间体氯化1-甲基-3-羟乙基咪唑、氯化N-羟乙基吡啶、氯化1-甲基-3-(2,3-二羟基)丙基咪唑和氯化N-(2,3-二羟基)丙基吡啶,考察了微波功率、辐射方式和辐射时间对反应产率的影响。结果表明,利用常规加热方法合成这4种离子液体中间体耗时长达24～96h,而用微波方法只需110～390s,反应时间大大缩短,同时微波方法较常规加热方法产率也略有提高。     

过渡金属离子液体EMIFeCl3的性质研究

在干燥高纯氩气氛的手套箱内, 直接将摩尔比为1∶1的高纯无水FeCl3与氯化1-甲基-3-乙基咪唑(EMIC)混合, 得到棕色透明的离子液体EMIFeCl4. 在293.15~343.15 K温度范围内测定了该离子液体的密度和表面张力. 利用Glasser经验方程和空隙模型研究了EMIFeCl4的性质, 并与离子液体EMIAlCl4进行比较, 指出空隙模型具有一定的合理性.     

含氰基离子液体的合成、表征及流变性质研究

摘要合成、 表征了一系列新的含氰基咪唑类离子液体. 测定了该离子液体的密度、 熔点及溶解性等物理性质, 研究了其在稳态、 瞬态和动态条件下的流变行为. 结果表明, 当剪切速率在0.1～50 s^-1范围内时, 其粘度不随剪切速率的变化而变化, 但随温度升高而降低, 粘流活化能随取代基长度变化呈现规律性变化. 对于1-丁基-3-氰乙基咪唑六氟磷酸盐离子液体, 维持剪切速率不变时, 其剪切应力和粘度均不随时间变化, 且随着温度的升高而降低; 在动态条件下, 在线性粘弹区, 复合粘度和损耗模量G″ 随温度升高而降低. 关键词     

1-甲氧基乙基-3-甲基咪唑甘氨酸离子液体的物理化学性质的研究

由于氨基酸基的独特性质,我们以甘氨酸作为阴离子,醚基咪唑基团作为阳离子合成了一种新型离子液体1-甲氧乙基-3-甲基咪唑甘氨酸[MOEMIM][Gly],并经过核磁共振氢谱、核磁共振碳谱和差示扫描量热进行表征。由于离子液体和水之间形成氢键导致传统的方法不能去除水的影响,所以在实验测定中,选用标准加入法在温度范围为298.15–338.15 K,每隔5 K测定离子液体[MOEMIM][Gly]的密度和表面张力。利用密度数据,计算得到离子液体[MOEMIM][Gly]的摩尔体积,并且摩尔体积随着温度的升高而增加,同时得到了热膨胀系数。根据离子液体[MOEMIM][Gly]的摩尔表面Gibbs自由能,改进了传统的Eötvös经验方程,使得方程具有更明确的物理意义,即截距C₀代表摩尔表面焓,它是一个与温度无关的常数,斜率则为摩尔表面熵,这表明改进的Eötvös方程不仅是一个经验方程,而且还是严格的热力学方程。另外,结合摩尔表面Gibbs自由能和改进的Eötvös方程,估算了离子液体的[MOEMIM][Gly]的表面张力,并与实验值进行比较,发现两者很好的一致。     

1-烷基-3-甲基咪唑系列室温离子液体表面张力的研究

合成了系列1-烷基-3-甲基咪唑四氟硼酸盐([C_2～7mim]BF₄)及六氟磷酸盐([C_4～7mim]PF₆)室温离子液体, 并通过核磁氢谱、红外光谱、质谱等手段对其进行了结构表征; 采用Wilhelmy白金板法, 在293～338 K范围内测定了离子液体的表面张力, 测试结果显示, 同类离子液体表面张力γ随温度的升高而线性下降, 同种离子液体的表面张力呈现出较宽的变化范围, 如293 K下, 表面张力值从[C₂mim]BF₄的50.4 mJ/m²到[C₇mim]BF₄的36.1 mJ/m². 最后对离子液体的表面性能进行了讨论.     

1-甲氧基乙基-3-甲基咪唑甘氨酸离子液体的物理化学性质的研究（英文）

由于氨基酸基的独特性质,我们以甘氨酸作为阴离子,醚基咪唑基团作为阳离子合成了一种新型离子液体1-甲氧乙基-3-甲基咪唑甘氨酸[MOEMIM][Gly],并经过核磁共振氢谱、核磁共振碳谱和差示扫描量热进行表征。由于离子液体和水之间形成氢键导致传统的方法不能去除水的影响,所以在实验测定中,选用标准加入法在温度范围为298.15–338.15K,每隔5 K测定离子液体[MOEMIM][Gly]的密度和表面张力。利用密度数据,计算得到离子液体[MOEMIM][Gly]的摩尔体积,并且摩尔体积随着温度的升高而增加,同时得到了热膨胀系数。根据离子液体[MOEMIM][Gly]的摩尔表面Gibbs自由能,改进了传统的E?tv?s经验方程,使得方程具有更明确的物理意义,即截距C0代表摩尔表面焓,它是一个与温度无关的常数,斜率则为摩尔表面熵,这表明改进的E?tv?s方程不仅是一个经验方程,而且还是严格的热力学方程。另外,结合摩尔表面Gibbs自由能和改进的E?tv?s方程,估算了离子液体的[MOEMIM][Gly]的表面张力,并与实验值进行比较,发现两者很好的一致。     

具有表面活性的功能化离子液体N-(三甲氧硅丙基)-N-甲基-2-吡咯烷酮盐酸盐的合成与表征

以N-甲基-2-吡咯烷酮和3-氯丙基三甲氧基硅烷单体为原料,利用SN2亲核取代反应合成具有一定表面活性的功能化离子液体N-(三甲氧硅丙基)-N-甲基-2-吡咯烷酮盐酸盐.通过元素分析、红外光谱和核磁共振对功能化离子液体进行表征,并测定了其表面张力和导电率.结果表明,合成的产物结构与其理论结构基本一致,具有较宽的液体温度范围和较低的表面张力,并具有较高的电导率,随着温度的升高,电导率逐渐增高.     

磺酸功能化离子液体催化3-羟基丙酸甲酯酯交换聚合反应

以磺酸功能化咪唑离子液体为催化剂,以3-羟基丙酸甲酯为原料,采用自身酯交换法合成了具有生物可降解性能的聚羟基脂肪酸酯.系统考察了离子液体种类、反应温度以及聚合反应时间对反应性能的影响,同时采用红外、核磁、热分析等手段对产物进行表征.研究结果表明:阴离子为CF3SO-3的磺酸功能化离子液体在120℃的低温下催化聚合反应所得聚酯Mw可达10 159,收率82.1%;通过水洗方法可有效去除产物中的离子液体催化剂,从而避免催化剂污染产物.     

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.     

Effect of tri-n-butyl phosphate on physical properties of dodecane–nitric acid system

Extraction power of solvent depends upon the physical properties of the system. Tri-n-butyl phosphate (TBP) in dodecane is a versatile solvent used in the nuclear fuel reprocessing like PUREX process. The study of physical properties like density, viscosity, interfacial tension and solubility for TBP–nitric acid–dodecane system will be helpful in carrying out different extraction studies during PUREX process. Thus, physical properties like density, viscosity, interfacial tension and solubility have been measured for TBP–nitric acid–dodecane system using pycnometer, viscometer, pendant drop method and high performance liquid chromatography respectively. It has been observed that density and viscosity increases but interfacial tension and solubility decreases with the concentration of TBP in dodecane–nitric acid system. Physical properties of 30 % TBP–nitric acid–dodecane system have also been studied in detail. All these studies will also be useful in stripping out dissolved TBP from the nuclear waste.     

Physicochemical characterization of n-butyl-3-methylpyridinium dicyanamide [corrected] ionic liquid

The room temperature ionic liquid n-butyl-3-methylpyridinium dicyanamide has been characterized. Physicochemical properties such as density, speed of sound, refractive index, surface tension, and kinematic viscosity of the studied liquid have been experimentally measured in a wide range of temperatures. From results, coefficients of thermal expansion, molar refractions, dynamic viscosities and entropies and enthalpies of surface formation per unit surface area at the studied temperatures have been derived. We have analyzed the achieved results for evaluating the effect of the anionic structure in these properties, getting interesting results which lead us to a better understanding of the behavior of the ions in the fluids. Moreover, thermal properties of several pyridinium-based ionic liquids have been investigated. Finally, from both dynamic viscosity values and glass transition temperature of the studied liquids, a detailed analysis of the behavior in fragility terms has been performed.     

Preparation and characterization of amino or carboxyl-functionalized ionic liquids

New functionalized ionic liquids,1-carboxylmethyl-3-methylimimidazolium hexafluorophosphate or fluoborate and 1-ami- noethyl-3-methylimimidazolium hexafluorophosphate or fluoborate have been synthesized and investigated.The obtained amino or carboxyl-functionalized ionic liquids were all characterized by FT-IR,~1H NMR and MS(ESI)and their properties such as freezing point,viscosity,solubility,specific gravity,surface tension,and interracial tension were also determined.     

Preparation and characterization of new room temperature ionic liquids

A new series [C(n)O(m )mim][X] of imidazolium cation-based room temperature ionic liquids (RTILs), with ether and alcohol functional groups on the alkyl side-chain has been prepared. Some physical properties of these RTILs were measured, namely solubility in common solvents, viscosity and density. The solubility of LiCl, HgCl(2) and LaCl(3) in room temperature ionic liquids was also determined. The features of the solid-liquid phase transition were analysed, namely the glass transition temperature and the heat capacity jump associated with the transition from the non-equilibrium glass to the metastable supercooled liquid. These properties were compared with those reported for the 1-n-alkyl-3-methylimidazolium [C(n )mim][X] series. While the density and solid-liquid phase transition properties are similar for both series, the new RTILs present a considerably lower viscosity and an increased ability to dissolve HgCl(2) and LaCl(3) (up to 16 times higher).     

Effect of temperature and composition on the density,viscosity, surface tension,and thermodynamic properties of binary mixtures of N-octylisoquinolinium bis{(trifluoromethyl)sulfonyl}imide with alcohols

Density and viscosity were determined for the binary mixtures containing the ionic liquid N-octylisoquinolinium bis{(trifluoromethyl)sulfonyl}imide ([C₈iQuin][NTf₂]) and 1-alcohol (1-butanol, 1-hexanol, and 2-phenylethanol) at five temperatures (298.15, 308.15, 318.15, 328.15, and 338.15) K and ambient pressure. The density and viscosity correlations for these systems were tested by an empirical second-order polynomial and by the Vogel–Fucher–Tammann equation. Excess molar volumes were described by the Redlich–Kister polynomial expansion. The density and viscosity variations with compositions were described by polynomials. Viscosity deviations were calculated and correlated by the Redlich–Kister polynomial expansions. The surface tensions of pure ionic liquid and binary mixtures of [C₈iQuin][NTf₂] with 1-hexanol were measured at atmospheric pressure at three temperatures (298.15, 308.15, and 318.15) K. The surface tension deviations were calculated and correlated by the Redlich–Kister polynomial expansion. The surface thermodynamic functions such as surface entropy and enthalpy were derived from the temperature dependence of the surface tension values. The critical temperature, parachor, and speed of sound for pure ionic liquid were described. A qualitative analysis on these quantities in terms of molecular interactions is reported. The obtained results indicate that ionic liquid interactions with alcohols are strong dependent on the special trend of packing effects and hydrogen bonding of this ionic liquid with hydroxylic solvents. As previously observed, an increase by a 1-alcohol carbon chain length leads to lower interactions on mixing.     

The effect of the anion on the physical properties of trihalide-based N,N-dialkylimidazolium ionic liquids

Low viscosity, high density trihalide-based 1-n-butyl-3-methylimidazolium ionic liquids have been prepared and characterised. Key physical properties (density, conductivity, melting point, refractive index, surface tension and diffusion coefficient) of the ionic liquids have been determined and are compared with those of other 1,3-dialkylimidazolium molten salts. The relationship between anion identity and the physical properties of the ionic liquids under investigation is discussed.     

水饱和离子液体中萘普生的酶法拆分

 考察了五种水饱和离子液体反应介质中固定化脂肪酶催化外消旋萘普生甲酯的水解. 结果表明,这些具有不同阴阳离子组合的咪唑基离子液体作为反应介质都能促进水解反应的有效进行,但在水饱和1-正丁基-3-甲基咪唑六氟磷酸盐(［bmim］PF6)中,反应进行得更快,转化率更高. 这些离子液体对脂肪酶均有一定的溶解作用并使溶解的脂肪酶失活. 脂肪酶在离子液体中的溶解度与其剩余活性之间有一定的相关性. 为了解决脂肪酶在离子液体中的溶解问题,使用非极性、高比表面积的无定形多孔硅胶YWG-C6H5对脂肪酶进行了固定化. 在水饱和［bmim］PF6中使用固定化脂肪酶催化反应,反应72 h的转化率为28.3%, 产物的对映体过量值为98.2%, 继续进行反应,转化率将增加,但产物的对映体过量值明显下降. 利用离子液体有别于传统有机溶剂的特性,对离子液体的循环使用、产物的回收和水的补充方法进行了研究. 在反复批式反应中,固定化脂肪酶连续使用五次,活性仅略微下降.     

Evidence of change in the molecular organization of 1-n-butyl-3-methylimidazolium tetrafluoroborate ionic liquid solutions with the addition of water

Physico-chemical properties of ionic liquids like density, viscosity, conductivity, surface tension and excess molar volume are strongly dependent on their concentration in aqueous solutions. 1-n-Butyl-3-methylimidazolium tetrafluoroborate/water solutions, at 25 °C, shows two clearly distinguished behaviors, corresponding to a water-rich and a salt-rich region, with distinct physico-chemical properties. It is shown that [BMIm][BF₄] exhibits surfactant properties. The results obtained are discussed in terms of the interactions between cations and anions of the ionic liquid and the water molecule. IR studies show that the addition of water modifies the organization of the ionic liquid molecules. The data collection reported is helpful for a variety of different technological applications and in particular for electrochemical applications, as capacitors, batteries and fuel cells among others.