Adsorption layer characteristics of multi-component surfactants solutions

An approximate model is derived for calculating the surface pressure, adsorption and rheological characteristics of multi-component surfactant mixtures from the adsorption parameters of the individual compounds. The proposed theory is validated with exact theoretical values and experimental data of equilibrium surface tensions and dilation rheology of binary mixtures of reorientable surfactants. It was shown that the given approximation for two, three and more components provides good agreement with the exact model for binary mixtures. The bubble profile analysis tensiometry is applied for studying the equilibrium surface tension and the rheological behaviour of mixed ternary C14EO8, C12EO5 and C10EO5 solutions in a wide range of total concentrations and surface oscillation frequencies. By comparison of experimental data with the calculated results it is possible to show that the proposed theoretical approach allows an accurate description of the adsorption and dilational rheological behaviour of the studied ternary surfactant mixtures.