Property And Infrared Spectrum Analysis Of Alkylimidazolium Ionic Liquids

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.