室温离子液体的制备及物化性能研究

Study on preparation and physical chemistry properties of room temperature ionic liquids

合成了[bm im]B r和[bm im]BF4室温离子液体,考察了其在不同溶剂中的溶解性能及导电性能,同时对离子液体在不同溶剂中的紫外吸收进行了测定。结果表明,离子液体在水、乙醇、乙酸、丙酮中可以较好的溶解,而在乙醚、苯、正己烷中不溶解;离子液体的电导率随浓度的增大和温度的升高而增大,在不同的溶剂中的电导率K不同,而且相差很大,其顺序为K(水作溶剂)>K(乙醇作溶剂)>K(乙酸作溶剂)。溶剂的极性对离子液体的紫外吸收影响较大,最大吸收波长的顺序为:λm ax(水为溶剂)<λm ax(乙醇为溶剂)<λm ax(乙酸为溶剂)。

Room temperature ionic liquids including 1-butyl-3-methylmimdazolum bromide （[ bmim ] Br） and 1-butyl-3-methyl mimdazolum tetrafluoroborate acid （ [ bmim ] BF4 ） were synthesized. Their solution and electric ability as well as ultraviolet absorption were measured in different solvents. The results showed that ionic liquids can dissolve better in water, ethanol, acetic acid and acetone, but not dissolve in ethyl ether,benzene and hexane. Electric conductivity（K） of ionic liquids increases with the increase of concentration and temperature. Electric conductivity has greater difference in different solvents and the gradation is K（ water as solvent） 〉 K（ ethanol as solvent） 〉 K（ actic acid as solvent）. The polarity of solvents has greater influence on UV absorption of ionic liquids and the gradation of the most absorption wave length（λmax） is λmax（water as solvent） 〈 λmax（ethanol as solvent） 〈 λmax（ actic acid as solvent）.