Thermodynamic parameters and counterion binding to the micelle in binary anionic surfactant systems

摘要: Abstract Competitive counterion binding of sodium and calcium to micelles, mixed micellization have been investigated in the systems dodecylsulfate (NaDS)/sodium decylsulfate (NaDeS) NaDS/sodium 4-octylbenzenesulfonate (NaOBS) order accurately model activity relevant species solution. The critical micelle concentration (CMC) equilibrium compositions mixtures these anionic surfactants, which is necessary for determining fractional measurements, thermodynamically modeled by regular solution theory. ideal (the parameter βM = 0) NaDS/NaOBS system, while NaDS/NaDeS has βM = −1.05 indicating a slight synergistic interaction. Counterion influenced ion concentration, vice versa. However, total degree essentially constant at approximately 0.65 charge negation micelle’s surface. coefficients can be quantitatively using simple relating concentrations bound unbound counterions.