ADSORPTION OF NONIONIC SURFACTANTS FROM WATER AND N-DECANE ON SILICONAND ALUMINUM-OXIDES

The adsorption of nonionic surfactants - isononylphenol ethoxylates wi th average degrees of ethoxylation n = 4, 6, and 10 - n from solutions in water and n-decane on silicon oxides with various specific surface and activated aluminum oxides was investigated. The equilibrium limit ing adsorption of nonionic surfactants and the minimum area per surfac tant molecule in a saturated adsorption layer were determined. It was established that within the range of nonionic surfactant concentration s studied, a monolayer of surfactant is formed on the surface of the o xides; in this case the orientation of the ethoxyl chains relative to the surface of silicon oxide depends on the surfactant concentration a nd varies from horizontal in the region of low surfactant concentratio ns to vertical at concentrations above 0.1 CMC in aqueous systems.