标题：Surface adsorption and micelle formation of surface active ionic liquids in aqueous solution
作者：Dong B;Li N;Zheng LQ;Yu L;Inoue T
作者机构：[Dong, B] Key Laboratory of Colloid and Interface Chemistry (Shandong University), Ministry of Education, Jinan 250100, China;[ Li, N] Key Laboratory 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
摘要：Aqueous solutions of three kinds of surface active ionic liquids composed of the 1-alkyl-3-methylimidazolium cation have been investigated by means of surface tension and electrical conductivity measurements at room temperature (298 K). The surface tension measurements provided a series of parameters, including critical micelle concentration (cmc), surface tension at the cmc (gamma(cmc)), adsorption efficiency (pC(20)), and effectiveness of surface tension reduction (Pi(cmc)). In addition, with application of the Gibbs adsorption isotherm, maximum surface excess concentration (Gamma(max)) and minimum surface area/molecule (A(min)) at the air-water interface were estimated. The effect of sodium halides, NaCl, NaBr, and NaI, on the surface activity was also investigated. It was found that both the pC(20) and the Pi(cmc) were rather larger than those reported for traditional ionic surfactants and the cmc values were somewhat lower than those for typical cationic surfactants, alkyltrimethylammonium bromides, and comparable to typical anionic surfactants, sodium alkyl sulfates. These results demonstrate that the surface activity of long-chained imidazolium IL is somewhat superior to that of conventional ionic surfactants.