Solubilization of <em>n</em>-alkane solubilizates &ndash; Part II: Solubilization in ionic surfactants

Abstract

In the present study we have investigated the solubilisation phenomena of <em>n</em>-alkane solubilizates into the micellar core of ionic surfactants. The particular system chosen is sodium dodecyl sulphate and the solubilizates are <em>n</em>-alkanes. The present study incorporates the cavity forming free energies of the monomer into water and in the micellar core as a major driving force. This model generalizes our previous theory for non-ionic solubilisation [<em>Indian J Chem</em>, 35 A (1996) 625]. The merit of thr model is that the extent of solubilisation, i.e. the mole fraction of solubilizate within the core can be calculated without using any adjustable parameter. The free energies of transfer of some n-alkanesolubilizates (octane to dodecane) from water to the micellar core of the corresponding n-alkyl sulphates (octyl to dodecyl) have also been calculated from the present theory. The results are in good agreement with the experimental data.