Direct method for measuring adsorption at the aqueous solution-gas interface based on the stabilization of foam films in hydrophobic tubes. The adsorption isotherm of sodium dodecyl sulfate

It was found that the hydrophobization of the inner surface of a tube offer s the stabilization of films of nonfoaming aqueous solutions closing the cr oss section of the tube. Based on this phenomenon, a modification of the kn own method of determining adsorption at the solution surface based on the s eparation of foam films from the solution was proposed for extending the po tentialities of this method to nonfoaming solutions. Adsorption of sodium d odecyl sulfate on the aqueous solution-air interface was investigated in th e range of low concentrations, which earlier was not easily accessible to m easurements by known methods.