Abstract
Aggregation behavior of the anionic surfactant sodium dodecyl sulfate (SDS) and the cationic surfactant dodecyltrimethylammonium chloride (DTAC) has been studied by conductivity measurement in aqueous/urea/NaCl medium. The deviation of experimentally executed critical micelle concentration (cmc) from their respective ideal values (cmcid) signifies the interaction between the studied surfactants. The experiments were performed at different temperatures in order to estimate different thermodynamic parameters. The negative values of Gibbs free energy (ΔGmo) point out the feasibility of the micellization behavior of the mixed systems as well as validate the feasibility of SDS‐DTAC interactions. The micellar mole fraction (X1) and the activity coefficients (f1 and f2) on the basis of different proposed model (Rubingh, Motomura, & Rodenas) and ideal mole fraction (Xid) were estimated, and obtained results illustrate the high contribution of DTAC in the mixed micellization, which exacerbates with the increase of the mole fraction of the DTAC. The interaction parameter (β) has also been investigated to get detailed insights of the interactions between the surfactants by concerning theoretical model proposed by Rubingh. The ΔGex values were attained to be negative at all α1 and temperatures, showing that mixed micelles are more stable than micelles of individual surfactants.
Aggregation behavior of two surfactant mixtures has been studied by conductivity measurement in aqueous/urea/NaCl medium at different temperatures. The deviation of experimentally executed critical micelle concentration (cmc) from their respective ideal values (cmcid) signifies the interaction between the surfactants. The values of micellar mole fraction (X1) and activity coefficients illustrate the high contribution of DTAC in the mixed micelles. The ΔGex values showing that mixed micelles are additional stable than micelles of individual surfactant.