Determination of the Critical Micelle Concentration of Imidazolium Ionic Liquids in Aqueous Hydrogen Peroxide.

The critical micelle concentrations (CMCs) of several imidazolium-based ionic liquids (ILs) in aqueous HO (50 wt % in HO) were determined by tensiometry, conductometry, and the rate of catalytic epoxidation of -cyclooctene. CMC values in aqueous HO were significantly lower compared to values in pure water. In both HO solution and water, the CMC of all ILs decreases with an increasing alkyl chain length and increases with a rising temperature. The degree of micelle ionization of 1-methyl-3-octylimidazolium tetrafluoroborate ([OMIM][BF]) was calculated by conductometry in a temperature range of 22-70 °C.