Properties of a Binary System Containing Anionic and Cationic Gemini Surfactants

Surface tension, fluorescence, and dynamic light scattering were used to investigate the properties of a binary surfactant system comprising an anionic gemini surfactant (DLMC) and cationic gemini surfactant (II-12-EO2). Surface tension measurements afforded the critical micelle concentration (cmc) of the mixture and the values are all lower than those of pure constituent surfactants. For the mixtures of II-12-EO2/DLMC, the micelle aggregation number decreases with the increase of II-12-EO2, and the micropolarity of the micelle is lowest when the molar fraction of II-12-EO2 is 0.5; the hydrodynamic radius (R (h)) of the mixed micelle first increases and then decreases with the addition of II-12-EO2, and larger micelles are obtained when the molar fraction of II-12-EO2 is 0.5 or 0.7.