Surface Properties and Mixed Micellization of Cationic Gemini Surfactants with Ethyleneamines

Herein, we report the Surface properties and mixed micellization of cationic gemini surfactants (butanediyl-1,4-bis(dimethylcetylammonium bromide), pentanediyl-1,5-bis(dimethylcetylammonium bromide), and hexanediyl-1,6-bis(dimethylcetylammonium bromide), respectively referred to as 16-4-16, 16-5-16, and 166-16) in the presence of different mole fractions of ethyleneamines (ethylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine) at 303 K. The surface properties (critical micelle concentration (CMC), C-20 (surfactant concentration required to reduce the Surface tension of the solvent by 20 mN.m(-1)), Gamma(max) (maximum surface excess), Amin (minimum surface area per molecule), and interaction parameter beta (for mixed monolayer formation at the aqueous solution/air interface (beta(sigma)) and for mixed micelle formation in aqueous medium (beta(m))) are reported. A synergistic effect has been observed in all instances that were found to be correlated with the chain length of ethyleneamines. The CMC Values of 16-s-16 decreased with increasing amine concentrations, and the extent of the effect followed the sequence; tetraethylenepentamine > triethylenetetramine > diethylenetriamine > ethylenediamine and 16-6-16 > 165-16 > 16-4-16. The standard Gibbs energies of adsorption (Delta G(ads)(0)) and the excess free energies of micellization (Delta G(ex)) of 16-s-16 with the airlines were also evaluated.