Thermodynamics of Solubilization of Polar Additives in Micellar Solutions
60Thermodynamic properties are very useful tools for the understanding the interactions governing mixed micelles formation. The main topic discussed in the present chapter concerns with the mathematical modeling of thermodynamic properties for water-surfactant-additive systems. The solubilizing effect of micelles toward polar additives are easily obtained by applying simple models to a given thermodynamic property of the additive as a function of the surfactant concentration at fixed and low additive concentration. From the measured property, the distribution constant of the additive between the aqueous and the micellar phases and the corresponding property for the additive in the micellar phase are simultaneously obtained. Information on micelle-additive interactions, which can be drawn from these properties, is briefly summarized as it depends on the nature of both the additive and surfactant.