Self-Association, Mixed Micellization, and Thermodynamic Studies of Sodium Dodecyl Sulfate (SDS) and Hexanediyl-1,6-Bis(Dimethylcetylammonium Bromide) (16-6-16)

The self-association, mixed micellization, and thermodynamic studies of a conventional anionic surfactant, sodium dodecyl sulfate (SDS), and a cationic gemini surfactant, hexanediyl-1,6-bis(dimethylcetylammonium bromide) (16-6-16), have been reported in the present investigation. The critical micelle concentration (CMC) of pure and mixed (SDS, 16-6-16, and SDS+16-6-16) surfactants was measured by electrical conductivity and dye solubilization measurements. The CMC values were found to increase with increasing temperature. The thermodynamic parameters (viz., the standard Gibbs energy (Delta G(m)(0)), the standard enthalpy change (Delta H-m(0)) and the standard entropy change (Delta S-m(0)) of the micellar and mixed micellar systems were evaluated.