Behavior of surface-active substances in aqueous solution and on solid surfaces

The interactions of cationic (CSA), anionic (ASA), and nonionic surfactants (NSA) with each other in aqueous solution and on solid surfaces are studied. To establish the mechanism of the adsorption of ASA and NSA from aqueous solutions onto layered silicates, modified with CSA, data on the interaction of corresponding surfactants in aqueous solutions of binary mixtures were used. It was shown that interactions between CSA and ASA led to the formation of cationic surfactants both in solution and on the surfaces of modified aluminosilicates. It was concluded that by analogy with solutions of binary mixtures of NSA on modified silicate surfaces, interaction occurs only with physically adsorbed CSA. With cations of modifier, chemically bonded to the active centers of the silicates, NSA reacts via a hydrophobic mechanism. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 45, No. 3, pp. 180–184, May–June, 2009.