Journal of Biochemistry International

The micellar and interfacial behavior of mixtures of the nonionic dodecyl, tetradecyl, hexadecyl poly glucoside surfactants with cationic cetyl trimethyl ammonium bromide were studied by surface tension measurements. Various physico chemical properties such as surface activity parameters (CMC, γCMC, A_min), the micellar and interfacial composition (X^m, X^σ), interaction parameters (β^m, β^σ) and activity coefficients (f₁^m, f₂^m, f₁^σ, f₂^σ) were evaluated. The micellar mole fractions were always higher than ideal values indicating high contributions of cationics in mixed micelles. Activity coefficients were less than unity indicating synergism in micelles. The negative free energies of mixing showed the stability of the mixed micelles of the surfactants. The wetting and foaming properties of mixed surfactant systems were also studied and they exhibit enhanced wetting and foaming properties.