Synergistic Behavior of Binary Mixed Micellar Solution

Conductivity measurement has been used to study the properties of aqueous solutions of the nonionic polyoxyethylene sorbitan(20)monooleate (T80) and the cationic 1,1′ lauryl amido propyl ammonium chloride (LAPACl) and their mixtures in the presence of 0.1 M HCl and at 303 K. The values of the critical micelle concentration (CMC) of the individual surfactants and their mixtures were determined from the conductometric measurements. Based on Rubingh's theory (approximation of the theory of regular solutions), the compositions of micelles (X1), and the parameters of interaction between the molecules of cationic and nonionic surfactants (β) were calculated for mixture of systems LAPACl+α T80 and T80+α LAPACl. The mixture LAPACl+α T80 showed synergistic interactions up to α=0.2 whereas those of T80+α LAPACl registered antagonistic behavior. The study disclosed that for cationic/nonionic surfactants mixtures, the priority is for mixtures of cationic base with small mole fraction of nonionic surfactant and not th...