添加离子液体会对表面活性剂在水溶液中的聚集行为产生重要影响.本文研究了吐温-20在中低浓度离子液体四氟硼酸1-丁基-3-甲基咪唑鎓([bmim][BF4])中的胶束化行为.随着[bmim][BF4]浓度(cIL)从0增加到0.2mol·L-1,吐温-20的临界胶束浓度逐渐增大.相比cIL＜0.05mol·L-1,在cIL＞0.05mol·L-1时加入[bmim][BF4]使吐温-20临界胶束浓度增大得更加显著.吐温-20胶束聚集数随着离子液体浓度的增加而逐渐减小,这一结果也说明加入离子液体会对吐温-20胶束的生成有抑制作用.吐温-20胶束化热力学研究表明,吐温-20在不同浓度离子液体中的胶束化是熵、焓共同驱动,并具有熵-焓补偿性.随着离子液体浓度的增加,吐温-20胶束平均粒径和胶束微粘性均表现出先增大后减小的变化,在cIL =0.05mol·L-1时达到最大值.%The presence of ionic liquids (ILs) has a significant impact on the aggregation behavior of surfactants in aqueous solution.In this article,micellization of non-ionic surfactant Tween-20 with the presence of middle and low concentration of hydrophilic ionic liquid [bmim] [BF4] (1-butyl-3-methylimidazolium tetrafluoroborate) was investigated.Critical micellization concentration (CMC) of Tween-20 showed an upward trend while increasing concentration of [bmim] [BF4] from 0 to 0.2 mol· L-1.Aggregation number of Tween-20 micelles decreased with increasing the concentration of [bmim] [BF4],which also indicated that the presence of [bmim][BF4] had great effect on hindering the micellization of Tween-20.Thermodynamic investigation demonstrated that the micellization of Tween-20 was driven by both entropy and enthalpy,and also showed entropy-enthalpy compensation.Meanwhile,average particle size and micro-viscosity of Tween-20 micelles increased first and then decreased with increasing concentration of [bmim] [BF4] from 0 to 0.2 mol· L-1,reaching the peak values at cL =0.05 mol·L-1.
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