标题：Aggregation behavior of 1-dodecyl-3-methylimidazolium bromide in aqueous solution: Effect of ionic liquids with aromatic anions
作者：Gu, Y.;Shi, L.;Cheng, X.;Lu, F.;Zheng, L.
作者机构：[Gu, Y] Key Laboratory of Colloid and Interface Chemistry, Shandong University, Ministry of Education, Jinan 250100, China;[ Shi, L] Key Laboratory of 更多
通讯作者地址：[Zheng, LQ]Shandong Univ, Key Lab Colloid & Interface Chem, Minist Educ, Jinan 250100, Peoples R China.
来源：Langmuir: The ACS Journal of Surfaces and Colloids
关键词：Aggregation behavior;aqueous solution;aromatic anions
摘要：The effects of ionic liquids (ILs), 1-butyl-3-methylimidazolium methylsulfonate (bmimMsa), 1-butyl-3-methylimidazolium benzenesulfonate (bmimBsa), and 1-butyl-3-methylimidazolium 2-naphthalenesulfonate (bmimNsa), on the aggregation behavior of 1-dodecyl-3-methylimidazolium bromide (C _(12)mimBr) in aqueous solution were investigated by surface tension, dynamic light scattering measurements, and 1H NMR spectroscopy. The ability to promote the surfactant aggregation is in the order bmimNsa > bmimBsa > bmimMsa. Nevertheless, only bmimNsa distinctly reduces both the CMC value and the surface tension at CMC. Due to the penetration of C _(10)H_7SO_3 -anions into the surfactant aggregate, bmimNsa is found to induce a phase transition from micelles to vesicles, whereas the other ILs only slightly increase the sizes of micelles. The combined effect of intermolecular interactions, such as hydrophobic effect, electrostatic attractions, and π-π stacking interactions, is supposed to be responsible for this structural transformation, in which π-π stacking plays an important role.