离子液体表面活性剂的合成与应用(Ⅴ)——离子液体表面活性剂的聚集热力学和状态

Synthesis and application of ionic liquid surfactants(Ⅴ) Thermodynamics and behavior of surfactant aggregation

离子液体表面活性剂聚集形成胶束的ΔG^0、ΔH^0和ΔS^0数据表明,聚集过程为熵驱动;离子液体表面活性剂的聚集数与传统表面活性剂相似,一般在40~160之间,其表观流体力学直径(D_h)为数纳米,高浓度形成囊泡时D_h可达100 nm;胶束表面反离子电离度在0.15~0.6之间;离子液体表面活性剂在水和有机溶剂中的聚集状态有差异,在水中的聚集状态与传统表面活性剂相似。

Aggregation of ionic liquid surfactants in aqueous solution is an entropy driven process, according to the data of its ΔG0, ΔH0 and ΔS0. Aggregation number of ionic liquid surfactants is similar to that of traditional surfactants ,40 - 160 in general. The apparent hydrodynamic diameter （Dh） of surfactant aggregation is several nanometers;but in case the concentration of the ionic liquid surfactant is high as forming vesicles, Oh may achieve 100 nm. Ionization degree of counter ions at the surface of surfactant micelles is about 0. 15 - 0. 6. Aggregation behavior of ionic liquid surfactants in water is similar to that of traditional surfactant, but the aggregation behavior of ionic liquid surfactants in water is different with that in organic solvents.