期刊
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
卷 302, 期 1-3, 页码 150-156出版社
ELSEVIER
DOI: 10.1016/j.colsurfa.2007.02.012
关键词
ionic liquids; micelle formation; dicationic ionic liquids; gemini surfactants; cationic surfactants; critical micelle concentration; surface tensiometry
The critical micelle concentration (CMC) values of an extensive class of 18 different monocationic and dicationic imidazolium-based ionic liquids (IL) were determined using surface tensiometry. An impressive correlation between the headgroup substituent chain length and the CMC value was obtained for a variety of structurally-related monocationic ILs. In one homologous series of ILs, a 3400-fold decrease in the CMC value was obtained by simply increasing the chain length of a fixed butylimidazolium headgroup. The CMC values of different classes of dicationic ionic liquids resembling gemini and bolaform surfactants were found to be highly dependent on the length of the employed linkage chain connecting the two headgroups as well as the nature of the free alkyl side chain. Dicationic ILs studied in this work containing longer alkyl linkage chains were found to produce modest decreases in the CMC whereas free alkyl chains appended onto the imidazolium cation provided over a 100-fold decrease in the CMC value. Dicationic ILs possessing hydrophilic and hydrophobic moieties analogous to structurally-related monocationic ILs exhibited much higher efficiencies at lowering the surface tension. (C) 2007 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据