Aggregation behavior of a fluorinated surfactant in 1-butyl-3-methylimidazolium ionic liquids

作者：Li Na; Zhang Shaohua; Zheng Liqiang^*; Wu Jiapei; Li Xinwei; Yu Li

来源：Journal of Physical Chemistry B, 2008, 112(39): 12453-12460.

DOI：10.1021/jp8054872

The aggregation behavior of a fluorinated surfactant (FC-4) was studied by surface tension measurements in 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]) and hexafluorophosphate ([bmim][PF6]) at various temperatures. A series of surface properties, including adsorption efficiency (pC(20)), effectiveness of surface tension reduction (Pi(CAC)), maximum surface excess concentration and minimum surface area/molecule (A(min)) at the air-water interface were estimated. By comparing the fluorinated surfactant with traditional surfactants, we deduced that the surface activity of the fluorinated surfactant in ILs was superior to the activity of other surfactants. From the CAC values and their temperature dependence, we estimated the thermodynamic parameters of aggregate formation. The thermodynamic parameters indicate that the aggregate of FC-4 in [bmim][BF4] is a traditional micelle, while the aggregate of FC-4 in [bmim][PF6] is nanodroplets composed of FC-4 molecules segregated from the solution phase. These results were further confirmed by H-1 NMR measurements.

• 出版日期2008-10-2
• 单位山东大学