The effect of salts on micellization in C12mimBr/Triton X-100 aqueous mixtures and on the surface properties of the solutions

Herein, we report our studies on the mixed aqueous solutions of 1-dodecyl-3-methylimidazolium bromide (C12mimBr) and Triton X-100 in the presence of sodium bromide and sodium chloride by surface tension and conductivity measurement methods. The critical micelle concentration and several other parameters such as maximum surface excess, minimum area per molecule and surface pressure at the CMC were calculated from the data of surface tension investigation. The critical micelle concentration values decreased with the increase of salt concentration. Rubingh’s theory was applied to calculate the mole fraction (X 1) of C12mimBr in the mixed systems. The results showed that X 1 increased most significantly with the concentration of the salt in the presence of NaBr. The values of standard Gibbs energies of micellization and interfacial adsorption have also been calculated; both were found to be negative for all systems, indicating the spontaneity of micellization and adsorption of the surfactants.