低黏度离子液体的合成、表征及性能研究

合成了两种以二氰胺根为阴离子的低黏度离子液体1-羟乙基-3-甲基咪唑二氰胺盐和1-丁基-3-甲基咪唑二氰胺盐,采用~1H NMR,FTIR,ESI-MS方法对其结构进行了表征。对两种离子液体的密度、黏度、溶解性、熔点和热稳定性等物化性质及热力学性质进行了考察,初步探讨了它们吸收CO_2的性能,并与实验室常用的离子液体1-丁基-3-甲基咪唑四氟硼酸盐(Bmim]BF_4])进行了对比。实验结果表明,二氰胺根的引入可降低离子液体的黏度,在阳离子上引入羟基可增加离子液体的水溶性,两种离子液体吸收CO_2的性能均优于Bmim]BF_4]。该研究结果为进一步探讨低黏度离子液体在CO_2捕集中的应用提供了基础数据。

Synthesis,Characterization and Properties of Low Viscous Ionic Liquids

Two low viscous ionic liquids 1-(2-hydroxyethyl)-3-methyl-imidazolium dicyanamide and 1-butyl-3-methylimidazolium were synthesized and characterized by means of ~1H NMR,FTIR and ESI-MS.Their physicochemical and thermodynamic properties,namely density,viscosity, solubility in some solvents,melting point,thermal stability and entropy,were studied.Their performance for CO_2 capture was discussed and compared with that of 1-butylimidazolium-3-methy terafluoroborate(Bmim]BF_4]).The introduction of dicyanamide groups can decrease the viscosity of the ionic liquids and the introduction of hydroxyl group can increase their water solubility.The performance of the two ionic liquids for CO_2 capture are better than that ofBmim]BF_4].