Solubilisation of two-component oil mixtures by micellar surfactant solutions

Abstract

Single-component oils are solubilised in different amounts and at different rates by a given micellar surfactant solution, the differences originating in the size and chemical nature of the solubilising oil molecule. This paper examines theoretically the case where solubilisation without fractionation occurs in a binary oil/single-component (micellar) surfactant solution. The amounts solubilised at intermediate bulk phase compositions are shown to depend on the ratio of the values for the two composition extremes and also on packing in the micelle. The rate of solubilisation is calculated using the expressions for the amounts solubilised. The theoretical predictions have been compared with some recent experimental data. The theory is shown to give a reasonable fit to both equilibrium and kinetic solubilisation data.