The adsorption of surfactants at the air-liquid interface from complex mixtures, measured by specular neutron reflection

The specular reflection of neutrons, in combination with isotopic labeling, has been shown to be a powerful technique for the study of surfactant absorption at the air-liquid interface. It can be used to obtain adsorbed amounts in complex multicomponent systems and to determine the structure of the adsorbed monolayer. The adsorption of the alkyl polyoxyethylene nonionics surfactant and mixtures of anionic and cationic surfactants with the nonionic surfactants is described. The effects of temperature, electrolyte, and less polar solvents (the addition of sorbitol) to the adsorption and structure are discussed.