Thermodynamic Parameters of Anionic Surfactant‐Quaternary Phosphonium Bromides Systems at the Cloud Point

The thermodynamics of clouding in an anionic surfactant, sodium dodecyl sulfate (SDS) and quaternary phosphonium bromides systems in the presence of glycerol are reported. The standard Gibbs energy change of solubilization (ΔsG°) for all of the additives was found to be negative. The standard enthalpy change (ΔsH°) and the standard entropy change (TΔsS°) values were found to be negative as well as positive depending upon the type and nature of the additive. The results were explained on the basis of their nature, effect on the water structure, and solubilization of these additives either in the micellar or aqueous phase.