Journal of Colloid and Interface Science, Vol.345, No.2, 392-401, 2010
Organization of amphiphiles. Part XI: Physico-chemical aspects of mixed micellization involving normal conventional surfactant and a non-ionic gemini surfactant
A systematic study on the behaviour of mixtures of p-phenyienediamine-tertiarybutyloxy-carbonyl-bis-glycamide (BAM) with ionic hexadecyl-trimethyl-ammonium bromide (CTAB), and sodium salt of dodecyl sulphate (SDS), and non-ionic surfactant (TritonX-100) in solution has been investigated through different physico-chemical measurements. The mixtures of BAM (0.0194 mM) with various amount of CTAB/SDS/TritonX-100 have been analyzed through absorbance, conductivity, surface tension and zeta potential measurements. The mixed system is found to be more surface active than the individual surfactants, the synergistic interaction being more prominent in system involving ionic surfactants compared to that of non-ionic surfactant. The mixed micellization behaviour is evidenced from the appearance/disappearance of the excimer of the fluorescent probe, maximum adsorption density at the interface, aggregation numbers of the surfactant mixtures and the surface charge of the conventional surfactants. A suitable interaction model, elucidating the organizational hierarchy of gemini-conventional surfactant at the micelle-water and air-water interface has been proposed. [GRAPHICS] . (C) 2010 Published by Elsevier Inc.
Keywords:Gemini surfactant;Zeta potential;Micropolarity;Surface charge;Mixed interaction;Interfacial adsorption energies;Maximum adsorption density