Reverse Micelle Formation of C12-EOx-C12 · 2Br in n-Heptane

With n-hexanol as the cosurfactant, quaternary ammonium Gemini surfactants C12-EOx-C12 · 2Br (x = 1, 2, 3) formed the reverse micelles in n-heptane. The critical reverse micelle concentrations (cmch) were determined using the absorption spectrum method with iodine as the probe. All values were less than the corresponding critical micelle concentration (cmcaq) in aqueous solution, where C12-EOx-C12 · 2Br formed the normal micelles. The cmch increased with increasing x, which was similar to the variation of cmcaq with x. The saturated amount of water solubilizated by the reverse micelles was enhanced by either increasing x or raising the temperature.