Congrong Yang,Suli Wang,Wenjia Ma,Luhua Jiang,Gongquan Sun
The alkaline stability of 1,2-dimethylimidazolium with various N3-substituents (including butyl, benzyl and vinylbenzyl) and corresponding quaternary ammonium small molecular compounds, and the 1,2-dimethylimidazolium- and quaternary ammonium-based membranes are systemically studied in the same condition. The spectroscopy (such as NMR, FT-IR, XPS and mass spectrum) results of the two kinds of small molecular compounds indicate that the quaternary ammonium cations are more stable than 1,2-dimethylimidazolium cations in 3 M KOH at elevated temperature, especially at 80 °C. Moreover, the alkaline stability of the 1,2-dimethylimidazolium cations would be influenced by the N3-substitutions of the imidazolium, and N3-butyl substituted cation shows a better alkaline stability. The quaternary ammonium-based membrane are also more stable than the 1,2-dimethylimidazolium-based membrane in 1 M KOH at 60 °C. In addition, the performance of the alkaline direct methanol fuel cell using quaternary ammonium-based membrane (22 mW cm −2 ) is much better than that of the fuel cell using 1,2-dimethylimidazolium-based membrane (0.04 mW cm −2 ).
The thermal conductivities of 1-butyl-3-methylimidazolium l-tryptophan ([BMIM][l-trp]), water, ethanol, [BMIM][l-trp] + water, [BMIM][l-trp] + ethanol, water + ethanol, and [BMIM][l-trp] + water + ethanol were investigated from 283.15 to 333.15 K covering the whole scale of concentration at atmospheric pressure with the transient hot wire method. The thermal conductivities of pure [BMIM][l-trp] decease linearly from 0.180 to 0.177 W·m–1·K–1 with increasing temperature. The uncertainty of the measurement was less than 2% at the 0.95 confidence level. The experimental data of binary and ternary mixtures were correlated by a second-order Scheffé polynomial as a function of composition and temperature. The average relative deviation of the calculated values with experimental data was 0.58%.
Xiaocai Meng,Jianying Wang,Haichao Jiang,Xinle Shi,Yongqi Hu
A functional 2-ethyl-4-methylimidazole alanine ([Emim][Ala]) ionic liquid was synthesized. Its density, viscosity, and surface tension were measured at the temperature range from 293.15 to 343.15 K at atmosphere pressure. The solubility of SO2 in pure [Emim][Ala] ionic liquid and the binary mixture of [Emim][Ala] and water was also investigated. The absorption\desorption mechanism of SO2 was proposed on the basis of 13C nuclear magnetic resonance and Fourier transform infrared spectroscopy. Results showed that SO2 was captured as ammonia sulfonic acid ester by pure [Emim][Ala], while for the binary mixture of [Emim][Ala] and water, the final product of SO2 absorption is alanine and [Emim]+[HSO3]−/[Emim]+2[SO3]2–.
危险品化学品经营许可证（带存储）