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This chapter is dedicated to the surface properties of mixed protein/surfactant adsorption layers, formed by two different experimental approaches, i.e. by sequential and simultaneous adsorption, respectively. A special modification of a drop profile analysis tensiometer, consisting of a coaxial double capillary, provides a unique protocol for studies of mixed surface layers formed by sequential adsorption of the individual components in addition to the traditional simultaneous adsorption from their mixed solution. A CFD simulation allowed to optimize the drop exchange process performed with the special double capillary arrangement. The experiments show that properties of sequentially formed... 

Mixed protein-surfactant adsorption layers can be built up in two different ways. The classical way is when all components adsorb simultaneously from a mixed solution. Alternatively, the components adsorb one after another, i.e. in a sequential way. In the present work, the formation of such surface layers has been studied with the random coil protein β-casein in the presence of added anionic surfactant SDS and compared for two different interfaces: the water-air (W-A) and water-hexane (W-H) interfaces. The used experimental technique is a drop profile analysis tensiometer PAT-1 specially equipped with a coaxial double capillary for drop volume exchange during the experiments. The results... 

The influence of the addition of the nonionic surfactants C12DMPO, C14DMPO, C10OH, and C10EO5 at concentrations between 10-5 and 10-1 mmol/L to solutions of β-casein (BCS) and β-lactoglobulin (BLG) at a fixed concentration of 10-5 mmol/L on the dilational surface rheology is studied. A maximum in the viscoelasticity modulus |E| occurs at very low surfactant concentrations (10-4 to 10-3 mmol/L) for mixtures of BCS with C12DMPO and C14DMPO and for mixtures of BLG with C10EO5, while for mixture of BCS with C10EO5 the value of |E| only slightly increased. The |E| values...