Mixed Micellization and Surface Properties of Ionic Liquids/Triton X-100 Mixture System in Aqueous Media

Abstract

Abstract Two binary systems of nonionic surfactant Triton X-100 and imidazolium ionic liquid surfactants with different carbon chain: C12mimBr (1-dodecyl-3-methylimidazolium bromide) and C14mimBr (1-tetradecyl-3-methylimidazoliumbromide) have been studied in this paper. The micellization and surface properties of the binary systems were determined by surface tension and conductivity methods, respectively. The critical micelle concentration (CMC), the maximum surface excess (Γmax), minimum area per molecule (Amin) and surface pressure at the CMC (ΠCMC) of single and mixed systems were obtained. Rubingh's theory was used to calculate the composition of the mixtures, and the molecular interaction parameter β. Negative value of β indicates synergism in mixed micelle formation. The order of absolute value of β and average β: C12mimBr/Triton X-100 > C14mimBr/Triton X-100. The values of ΔG0 m and ΔG0 ads have also been calculated, and both of them were found to be negative in all pure and mixed surfactants, indicating the spontaneity of micellization and adsorption of the surfactants.