Adsorption of hen egg-white lysozyme at the air–water interface in presence of sodium dodecyl sulphate

The mixed adsorption layers of hen egg-white lysozyme/SDS for fixed protein concentration and varying surfactant concentrations at the air/water interface have been studied using bubble and drop profile analysis tensiometry and ellipsometry. The set of equilibrium and kinetic data are compared with thermodynamic and adsorption kinetic models developed recently. The parameters used for the mixed system are essentially those parameters obtained for the individual components. For a lower SDS concentrations the agreement with the model is good while in the transition region to a mainly surfactant controlled surface layer is poor.