聚丙烯酸水凝胶对氯化-1-丁基-3-甲基咪唑离子液体的吸附热力学和动力学研究

通过水溶液聚合法制备了聚丙烯酸水凝胶（polyacrylic acid,PAA）,研究了溶液酸碱度和温度对聚丙烯酸水凝胶吸附氯化1-丁基3-甲基咪唑离子液体的影响。结果表明,水凝胶对氯化1-丁基3-甲基咪唑离子液体的吸附量随溶液pH值增大而逐渐增大,pH=2～4时增幅明显,而pH大于4时变化趋于缓慢;随温度的升高而逐渐降低。该等温吸附行为基本符合Langmuir吸附等温式,由二级吸附动力学模型获得的吸附过程活化能（Ea=52.470 kJ/mol）可以看出,PAA对氯化1-丁基3-甲基咪唑的吸附属于化学吸附范畴。

Thermodynamic and kinetic studies of adsorption of 1-butyl-3- methylimidazole chloride ionic liquid onto PAA hydrogel

A super absorbent of PAA hydrogel was prepared by solution polymerization method. The pH value and the temperature of solution had an effect on the adsorption of 1-butyl-3-methylimidazole chloride ionic liquid onto PAA hydrogel. The results showed that the adsorption capacities of 1-butyl-3-methylimidazole chloride ionic liquid increased with increasing pH value. When pH=2~4, the adsorption capacities increased significantly,while pH was 4, it increased slowly with increase of pH. The adsorption capacities of ionic liquid decreased with increasing temperature. The adsorption behavior of 1-butyl-3-methylimidazole chloride could be described reasonably well by Langmuir isotherm. Chemical adsorption may be inferred by the activation energy E_a (E_a=52.470 kJ/mol)of adsorption obtained from the pseudo-second-order kinetic model.