节点文献

烷基咪唑体系离子液体的性质及红外光谱分析

Property and Infrared Spectrum Analysis of Alkylimidazolium Ionic Liquids

【作者】 魏来

【导师】 田鹏;

【作者基本信息】 沈阳师范大学 , 分析化学, 2011, 硕士

【摘要】 实验用溴代正烷烃和N-甲基咪唑合成了溴化1-烷基-3-甲基咪唑离子液体,进一步用溴化1-烷基-3-甲基咪唑离子液体和硝酸钠合成硝酸1-烷基-3-甲基咪唑离子液体,并用红外光谱仪对合成的溴化烷基咪唑离子液体和硝酸烷基咪唑离子液体进行红外光谱表征,表明合成了目标产物。测定了溴化1-烷基-3-甲基咪唑离子液体和硝酸1-烷基-3-甲基咪唑离子液体在273.15K-343.15K之间的密度,并将实验的测定值lnρ对(T-273.15)进行线性拟合,发现密度与温度具有很好的线性关系。由拟合方程求出离子液体的热膨胀系数进而求出摩尔体积、标准熵等有关体积性质的相关数值。并分别对这两个体系离子液体的密度进行整体分析,发现两体系都是随着咪唑环上碳链的逐渐增加密度在逐渐减小。又对溴化烷基咪唑离子液体和相应的硝酸烷基咪唑离子液体两体系的密度进行对比分析,发现溴化1-烷基-3-甲基咪唑离子液体的密度小于对应的硝酸1-烷基-3-甲基咪唑离子液体的密度。测定了溴化1-烷基-3-甲基咪唑离子液体和硝酸1-烷基-3-甲基咪唑离子液体在283.15K-313.15K之间的电导率,发现两体系的电导率都随温度的升高而明显升高,并将电导率测定值σ对(T-273.15)进行拟合得到拟合方程和相关系数,发现电导率与温度的关系符合VTF经验方程。分别对这两个体系离子液体的电导率进行整体分析,发现两体系都是随着咪唑环上碳链的逐渐增加离子液体的电导率在逐渐减小。在室温下分别测量溴化烷基咪唑离子液体和硝酸烷基咪唑离子液体在不同溶剂中不同浓度下的电导率,发现离子液体在不同的溶剂中电导率有很大的差异。又对溴化烷基咪唑离子液体和相应的硝酸烷基咪唑离子液体两体系的电导率进行对比分析,发现溴化1-烷基-3-甲基咪唑离子液体的电导率小于对应的硝酸1-烷基-3-甲基咪唑离子液体的电导率。用红外光谱法定量分析乙醇中硝酸1-烷基-3-甲基咪唑离子液体的含量,根据Lambert-Beer定律,可知吸光度值与浓度是呈线性关系的,可表示为方程A=kc+m。最佳的定量分析峰要求吸光度值随浓度的变化幅度较大,并且其吸光度值与浓度相关度较高。即A=kc+m的斜率和相关系数都较大,用最小二乘法计算各个波数下的斜率和相关系数,选择斜率和相关系数都比较大的峰作为分析峰,实验表明所选的分析峰的定量标准曲线的相关系数较高且加标回收率结果也比较好。

【Abstract】 In this paper, bromo-l-alkyl-3-methylimidazolium ionic liquids were synthesized by alkyl bromide and N-methyl-imidazole, and further nitric-1-alkyl-3-methylimidazolium ionic liquids were synthesized by bromide-1-alkyl-3-methylimidazolium ionic liquids and sodium nitrate, the synthesis of alkyl bromides and alkyl nitrate ionic liquid were analyzed by infrared spectrum, and the synthesis of ionic liquids were proved to be target products by infrared spectrum.The density of bromide-l-alkyl-3-methylimidazolium ionic liquids and nitric-l-alkyl-3-methylimidazolium ionic liquids were determined between 273.15K-343.15K, and the value of experimental determination lnp on (T-273.15) fit linear, the density and the temperature had a good linear relationship was discovered. The thermal expansion coefficient of ionic liquid was obtained from the fitting equation and then the molar volume, the standard entropy related to the nature of the relevant volume number was educed. The density of these two systems was respectively overall analyzed. With the two systems we found that on the carbon chain of imidazolium increasing the density decreases. The density of alkyl bromide ionic liquid and the corresponding alkyl nitrate ionic liquid were compared analyzed. We found that the density of bromide 1-alkyl-3-methylimidazolium ionic liquid was less than the density of the corresponding nitric-1-alkyl-3-methylimidazolium ionic liquid.The conductivity of bromide-1-alkyl-3-methylimidazolium ionic liquids and nitric-1-alkyl-3-methylimidazolium ionic liquids were determined between 283.15K-313.15K, the conductivity of the two systems were significantly higher with the temperature increases and the value of experimental determination on (T-273.15) was fitted, the regression equation and correlation coefficient were found, the conductivity and temperature was discovered accord with the VTF empirical equation. The conductivity of these two systems was respectively overall analyzed. With the two systems we found that on the carbon chain of imidazolium ionic liquids gradually increase the conductivity gradually decreases. The conductivity of these two systems in different solvents at different concentrations were measured at room temperature, ionic liquids in different solvents have very different electrical conductivity. The conductivity of alkyl bromide ionic liquid and the corresponding alkyl nitrate ionic liquid were compared analyzed. We found that the conductivity of bromide-1-alkyl-3-methylimidazolium ionic liquid was less than the conductivity of corresponding nitric-1-alkyl-3-methylimidazolium ionic liquid.The nitric-1-alkyl-3-methylimidazolium ionic liquids content in ethanol were quantitative analysis by infrared spectrum according to Lambert-Beer’s law, concentration and absorbance was assumed linear, and can be expressed as equation A=kc+m.The best quantitative analysis of peak requested absorbance with the concentration had big variations, the absorbance value and the concentration had higher correlation. The slope and correlation coefficients of A=kc+m were larger, used the least squares method to calculate the slope of each wave number and the correlation coefficient, selected the peak which slope and correlation coefficient larger than the other peaks, as the experiment proved that the correlation coefficient of the standard curve of the selected analysis peak was high and the recovery results were better.

节点文献中: 

本文链接的文献网络图示:

本文的引文网络