室温离子液体1-丁基-3-甲基咪唑磷酸二丁酯的电导率研究

利用磷酸三丁酯与N-甲基咪唑在恒温150℃下一步合成了离子液体1-丁基-3-甲基咪唑磷酸二丁酯,考察了其在丙酮,水,DMF,乙酸溶剂中的电导率及摩尔电导率。实验发现该离子液体在不同溶剂中的电导率(κ)相差很大,其顺序为κa(水)>κb(DMF)>κc(丙酮)>κd(乙酸)。在相同温度下,电导率及摩尔电导率随浓度的增大而增大;在相同浓度下,电导率及摩尔电导率随温度的升高而增大。     

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。     

四种烷基咪唑磷酸酯离子液体的热力学性质

针对烷基咪唑磷酸酯离子液体的热物性数据较少的问题,本文在常压下测定了1-乙基-3-甲基咪唑磷酸二氢盐（[EMIM][DHP]）、1-乙基-3-甲基咪唑磷酸二甲酯盐（[EMIM][DMP]）、1-乙基-3-甲基咪唑磷酸二乙酯盐（[EMIM][DEP]）、1-丁基-3-甲基咪唑磷酸二丁酯盐（[BMIM][DBP]）四种烷基咪唑磷酸酯离子液体的密度、黏度（293.15～353.15K）和电导率（293.15～343.15K）,并且测定了四种离子液体的热稳定性。结果表明,离子液体的密度、黏度随温度的升高而减小,而电导率随温度的升高而增大。采用自然对数方程关联四种离子液体的密度,根据实验值计算到了离子液体体积性质;采用VFT方程关联离子液体黏度和电导率,其中密度与电导率的实验值与模型相关系数R2达到0.9999,黏度相关系数R2达到0.99999,实验测定的数据与模型一致;四种离子液体的热稳定性相近,分解温度均在271.9～278.6℃范围内;瓦尔登规则分析表明,四种烷基咪唑磷酸酯离子液体符合Walden规则,而[EMIM][DMP]和[EMIM][DEP]被归类为“good ionic liq...     

1-丁基-3-甲基咪唑四氟硼酸盐的合成研究

以1-溴丁烷和N-甲基咪唑为原料合成了中间体溴化1-丁基-3-甲基咪唑,以中间体与NaBF4进行复分解反应制备了离子液体1-丁基-3-甲基咪唑四氟硼酸盐。探讨了投料比、反应时间、反应温度对中间体和1-丁基-3-甲基咪唑四氟硼酸盐产率的影响,确定了最佳合成条件。在此工艺条件下,1-丁基-3-甲基咪唑四氟硼酸盐产率可达85%以上。     

1-(3-(N-胱胺)丙基)-3-甲基咪唑溴离子液体的合成与表征

以1,3-二溴丙烷与N-甲基咪唑为原料,制备1-溴丙基-3-甲基咪唑溴盐离子液体。采用二叔丁基二碳酸酯保护胱胺的单侧氨基,然后再与1-溴丙基-3-甲基咪唑溴盐发生取代反应生成1-(3-(N-胱胺)丙基)-3-甲基咪唑溴离子液体;分别用核磁、红外对中间体和产物进行表征,结果表明我们成功合成了新型氨基功能化离子液体。     

五种新合成酯基取代的咪唑类离子液体电导率的测定与分析

离子液体的电导率性质反映了离子液体的导电性能,与溶剂中的电离度以及离子的溶剂化能力密切相关。为了研究本实验室合成的5种酯基取代的离子液体的电导率,用DDS307电导率仪测定1-乙酸甲酯基-3-甲基咪唑双三氟甲基磺酰亚胺([MIMCH₂COOCH₃]NTf₂)、1-乙酸乙酯基-3-甲基咪唑双三氟甲基磺酰亚胺([MIMCH₂COOCH₂CH₃]NTf₂)、1-乙酸正丙酯基-3-甲基咪唑双三氟甲基磺酰亚胺([MIMCH₂COOCH₂CH₂CH₃]NTf₂)、1-对甲基苯甲酸甲酯基-3-甲基咪唑双三氟甲基磺酰亚胺([MIMCH₂C₆H₄COOCH₃]NTf₂)和1-对甲基苯甲酸乙酯基-3-甲基咪唑双三氟甲基磺酰亚胺([MIMCH₂C₆H₄COOCH₂CH₃]NTf₂)在二甲基亚砜、甲醇、乙腈和乙酸乙酯中的电导率数据。结果表明,其他条件不变时,在一定浓度范围内,离子液体的电导率随着其浓度的增大而增大;在一定温度范围内,随着温度的升高,离子液体电导率增大;4种溶剂相比电导率从小到大顺序依次为乙酸乙酯、二甲基亚砜、甲醇、乙腈,反映了带酯基的5种离子液体与乙酸乙酯的相互作用。     

1-烷基-3-甲基咪唑磺胺醋酰盐离子液体的合成

以甲基咪唑为原料,合成1-烷基-3-甲基咪唑溴盐中间体,与磺胺醋酰银反应,合成1-烷基-3-甲基咪唑磺胺醋酰盐离子液体,并研究其抑菌性能。考察投料比、反应温度对1-丁基-3-甲基咪唑溴盐中间体产率的影响;烷基碳原子数量对中间体的合成、离子液体的合成及其抑菌性能的影响。结果表明,n(N-甲基咪唑)∶n(溴代正丁烷)=1∶1.3,反应温度90℃时,1-丁基-3-甲基咪唑溴盐产率最高;烷基碳原子数量增加,中间体的产率逐渐变低,对离子液体合成产率及其抑菌性能影响较小。     

1-烷基-3-甲基咪唑磺胺醋酰盐离子液体的合成

以甲基咪唑为原料,合成1-烷基-3-甲基咪唑溴盐中间体,与磺胺醋酰银反应,合成1-烷基-3-甲基咪唑磺胺醋酰盐离子液体,并研究其抑菌性能。考察投料比、反应温度对1-丁基-3-甲基咪唑溴盐中间体产率的影响;烷基碳原子数量对中间体的合成、离子液体的合成及其抑菌性能的影响。结果表明,n(N-甲基咪唑)∶n(溴代正丁烷)=1∶1.3,反应温度90℃时,1-丁基-3-甲基咪唑溴盐产率最高;烷基碳原子数量增加,中间体的产率逐渐变低,对离子液体合成产率及其抑菌性能影响较小。     

离子液体1-甲基-3-乙基咪唑四氟硼酸盐和1,2-二甲基-3-乙基咪唑四氟硼酸盐的热力学和电导性质研究

在室温下合成了离子液体1-甲基-3-乙基咪唑四氟硼酸盐([Emim]BF4)和1,2-二甲基-3-乙基咪唑四氟硼酸盐([Dmeim]BF4),通过红外光谱对其进行了结构表征。分别测定了两种离子液体在不同温度下的密度、表面张力、粘度和电导率,发现当咪唑环2位碳上增加甲基取代基后其密度、表面张力和电导率均呈下降趋势,而粘度呈上升趋势且变化较大,如在298.15 K时[Emim]BF4的粘度为842 mPa.s,[Dmeim]BF4的粘度为8 293 mPa.s。并根据特定的经验方程估算了两种离子液体的热膨胀系数、摩尔体积、标准熵和晶格能等重要的性质参数。     

咪唑类离子液体的合成与表征

通过两步法合成了阳离子含亲水性咪唑离子基和疏水烷基链结构、阴离子相同的1-乙基-3-甲基咪唑醋酸盐([Emim]Ac)、1-丁基-3-甲基咪唑醋酸盐([Bmim]Ac)、1-己基-3-甲基咪唑醋酸盐([Hmim]Ac)3种离子液体。利用红外光谱对其进行结构表征,并探究温度对pH的影响;考察温度、离子液体质量浓度、有机溶剂对电导率的影响;测定临界胶束浓度和溶解性。结果表明,[Emim]Ac、[Bmim]Ac、[Hmim]Ac碱性递减,其在不同溶剂中的电导率随温度(28～60℃)的升高、离子液体质量浓度(6～20 g/L)的增加而增大,且受溶剂性质影响;临界胶束浓度分别为11.46、9.92 g/L和9.72 g/L;其溶解性随溶剂极性的增强、侧链烷基的伸长而增大。     

Enhancement of Electrical Conductivity of Polyethylene Terephthalate (PET) Fabrics via Ionic Liquids

In this study, polyethylene terephtalate (PET) fabrics were treated with two types of ionic liquids, 1-ethyl-2,3-dimethylimidazolium ethyl sulfate (EIL) and methyl-tri-n-butylammonium methyl sulfate (BIL), resulting in noticeably better long-term electrical conductivity of treated PET fabrics. Thermal conductivity, thermal stability, surface morphology and chemical structure were also explored. The effects of concentration of EIL (2, 6, 10 w/v %) and BIL (10, 15, 20 w/v %) ionic liquids were discussed. With the given set up, surface resistivities of the PET fabrics decreased with treatment application of the ionic liquids. Besides, BIL treatment provided higher electrical conductivity as compared with EIL. Moreover, surface resistivity presented diminishing tendency with increasing the concentration. It is also found that thermal degradation temperatures of the PET fabrics decreased with ionic liquids treatment. A coating layer was observable on surface of the fabric and in the gaps of the yarns with the ionic liquids treatment. This work provided a novel method for obtaining enhanced electrically conductive PET fabrics for textile industry.     

[bmim][BF_4]、[bmim][PF_6]离子液体及其与DMF二元体系在293.15～338.15K下的粘度

为获得离子液体与有机物物理性质的数据,常压下,293.15～338.15 K温度范围内,分别测定了1-丁基-3-甲基咪唑四氟硼酸盐（[bmim][BF4]）、1-丁基-3-甲基咪唑六氟磷酸盐（[bmim][PF6]）2种咪唑类离子液体以及它们和N,N-二甲基甲酰胺（DMF）构成的2个二元体系的粘度,采用Vogel-Tamman-Fulcher（VFT）方程和Arrhenius-like方程对所测粘度数据进行关联。结果表明,同一温度下,3种纯溶液粘度大小顺序依次为：DMF〈[bmim][BF4]〈[bmim][PF6]。[bmim][BF4]、[bmim][PF6]离子液体及其与DMF构成的二元体系的粘度均随着温度的升高和DMF摩尔分率的增加而降低。实验条件下,DMF＋[bmim][BF4]和DMF＋[bmim][PF6]二元体系的粘度变化范围分别为1.26～125.5 MPa·s和1.11～165.7 MPa·s。VFT方程对于DMF-[bmim][BF4]与DMF-[bmim][PF6]体系的关联结果比Arrhenius-like方程较好,其总平均绝对误差、总平均相对误差、以及总平均标准方差分别为0.561 9 MPa·s和0.918 6 MPa·s、0.026 8 MPa·s和0.020 9 MPa·s、0.725 5 MPa·s和1.125 1 MPa·s。     

Cation and anion sizes influence in the temperature dependence of the electrical conductivity in nine imidazolium based ionic liquids

In this paper we present experimental data on the temperature dependence of the electrical conductivity, σ, in nine different imidazolium based ionic liquids. We have measured four 1-(alkyl chain)-3-methyl imidazolium tetrafluoroborate (C_nMIM-BF₄) ionic liquids, with C_n representing ethyl, butyl, hexyl and octyl chains, to study the dependence of σ with the cation length. Moreover, to study the influence of the anion size in the electrical conductivity, we measured six different EMIM-X, with X being, from smaller to bigger sizes, Cl⁻, Br⁻, BF₄⁻, PF₆⁻, ethyl sulfate and tosylate. The measurements were performed at atmospheric pressure, and the studied temperature range covers the liquid phase of the analyzed compounds. We have fitted the electrical conductivity data of the nine ionic liquids using a Vogel-Tamman-Fulcher (VTF) equation with high precision. We observe from the measured data that the electrical conductivity decreases its value as the alkyl chain of the cation increases. In contrast, we do not observe that dependence with the anion size, where there seems to be an optimal size (that of BF₄⁻) for which σ reaches its maximum value, being lower for smaller or bigger anion sizes. Finally, if we plot the natural logarithm of σ versus the distance in temperature to the glass transition one for each IL, we observe that the resulting straight lines are ordered with the anion (or cation) sizes for all nine compounds measured, i.e., lower σ values for bigger sizes.     

Solvent-free chemical functionalization of hydrogen-terminated boron-doped diamond electrodes with diazonium salts in ionic liquids

This paper reports on green chemical functionalization of hydrogen-terminated boron-doped diamond (BDD) surfaces with aryldiazonium salts in the presence of ionic liquids. The reaction takes place at room temperature in air without any external bias in either hydrophobic (1-butyl-3-methylimidazolium hexafluorophosphate) or hydrophilic (1-butyl-3-methylimidazolium methyl sulfate) ionic liquids. The resulting surfaces were characterized using X-ray photoelectron spectroscopy and electrochemical measurements.     

Ionic liquids containing an alkyl sulfate group as potential electrolytes

Various types of ionic liquid (IL) containing an alkyl sulfate group are synthesized and their physical and electrochemical properties are investigated. The temperature dependency of dynamic viscosity and ionic conductivity are measured for these ILs. The low temperature phase behaviour of the ethylsulfate salts is investigated using differential scanning calorimetry. Three ethylsulfate-containing ionic liquids exhibit wide electrochemical windows of about 5.0 V, and one pyrrolidinium-containing ionic liquid shows a conductivity of 3.8 mS cm⁻¹. The various cations of alkylsulfate-containing ionic liquids are shown to greatly influence viscosity, density, and conductivity. Absorbance solvatochromic probe, Nile Red is used to investigate the relative polarity of alkylsulfate base ionic liquids compared with several organic solvents. The electrochemical and thermal stabilities of these ILs make them promising electrolytes for use in electrochemical devices.     

离子液体中结晶分离熊果酸和齐墩果酸研究

为拓展结晶溶剂的范围和提高结晶分离熊果酸和齐墩果酸的性能,引入离子液体作为结晶溶剂。测定了熊果酸和齐墩果酸在六种离子液体+乙醇溶液中的溶解度数据,根据该数据,选取1-辛基-3-甲基咪唑六氟磷酸+乙醇混合溶液作为溶剂对熊果酸和齐墩果酸进行了结晶分离,并采用单因素实验对结晶工艺进行了初步优化。结果表明:在1-辛基-3-甲基咪唑六氟磷酸质量分数5%,熊果酸和齐墩果酸质量比1.5∶1,结晶温度30℃,结晶时间14 h的条件下,结晶产物中齐墩果酸的质量分数可以达到85%左右。     

Study of the conductivity behavior of pyridinium-based ionic liquids

In this work, ionic conductivity data as a function of temperature in the pyridinium-based ionic liquids 1-butylpyridinium tetrafluoroborate, 1-butylpyridinium triflate, 1-butyl-2-methylpyridinium tetrafluoroborate, 1-butyl-3-methylpyridinium tetrafluoroborate, 1-butyl-4-methylpyridinium tetrafluoroborate, 1-butyl-3-methylpyridinium dicyanamide, and 1-octyl-3-methylpyridinium tetrafluoroborate, are reported. A comparison of results for this series of ionic liquids has been used to evaluate the influence of the ionic structural characteristic in this transport property. Temperature dependence of experimental values has been fitted by means of the Vogel-Fulcher-Tammann equation, and from their parameters, maximum conductivity and activation energy for conduction have been derived. From conductivity parameters and the glass transition temperature, a detailed analysis has been performed in fragility terms. Finally, the classical Walden rule has been used to classify the ionic liquids depending on the relationship between conductivity and fluidity.     

咪唑型离子液体热物理性质测量

利用自行搭建的热线法液体热导率和热扩散系数装置测试了两种咪唑型离子液体([C₆mIm][BF₄]和[C₄mIm][BF₄])在不同温度下的热导率和热扩散系数。根据文献报道的密度数据获得了样品的比热容。结果表明:两种离子液体的热导率与温度的相关性不大;两种阳离子结构相似的离子液体热扩散率相近, 热扩散率随温度的升高有明显的变化, 本文认为离子液体内部的离子动量分布与温度紧密相关, 离子间的动量交换随温度的升高而增加, 离子动量分布随温度升高逐渐趋于一致, 离子间碰撞产生的动量交换不再明显改变离子的动量, 导致热扩散率的变化随温度升高而减小。     

Development of Conductivity of Acrylic Polymer Using Ionic Liquids Incorporated with Zinc Oxide Nanoparticles

In this study, we synthesized antistatic and ultraviolet-resistant acrylic films with a combination of ionic liquids and ZnO nanoparticles for the prevention of static electricity and ultraviolet instability. ZnO and two different ionic liquids such as 1-ethyl-2,3-dimethylimidazolium ethyl sulfate and methyl-tri-n-butylammonium methylsulfate were preferred to achieve conductive and ultraviolet-resistant acrylic films. To obtain the highest ultraviolet protection factor and the lowest surface resistivity for the acrylic film, the combined effect of ZnO nanoparticles and the ionic liquids was utilized. The surface resistivity, thermal conductivity and effusivity, thermogravimetric analysis, and ultraviolet resistivity of the films were investigated. Surface morphology of the films and distribution of ZnO were also observed by scanning electron microscopy. The acrylic polymer exhibits higher ultraviolet resistance and lower transmission even in the low content of ZnO nanoparticles as compared with the neat polymer. The film consisting of methyl-tri-n-butylammonium methylsulfate ionic liquid showed the highest electrical conductivity performance even after 150 days. Consequently, ZnO nanoparticles are determined to be influential on ultraviolet-resistant properties, whereas ionic liquids are efficient on electrical conductivity performance of the acrylic polymer.     

Ionic-tagged catalytic systems applied to the ethenolysis of methyl oleate

A novel high selective ionophilic Hoveyda-type complex for the methyl oleate ethenolysis was prepared from Grubbs first generation catalyst. Ethenolysis under classical biphasic systems in ionic liquids showed to be mass-transference limited. This drawback was successfully solved by the catalyst dispersion on high specific surface area inorganic supports through a thin layer of ionic liquids (ILs). The supported ionic liquid phase (SILP) catalyst properties were patterned by the support type, IL cation and support/IL mass ratio. The SILP prepared with the IL 1-isopentyl-3-methylimidazole hexafluorophosphate and silica showed a turnover number higher (up to 2350) than that of biphasic systems (up to 1045).