Adsorption of conventional and gemini cationic surfactants in nonswelling and swelling layer silicate

The adsorption of conventional (cetyltrimethylammonium bromide) and its corresponding gemini cationic surfactant [ethanediyl-alpha,beta-bis(cetyl dimethyl ammonium bromide)] in both swelling (montmorillonite) and nonswelling (kaolinite) layer silicates was investigated by adsorption isotherms and X-ray diffraction techniques. Adsorption studies showed that the adsorption of gemini surfactant was more efficient than that of the corresponding conventional surfactant on both kaolinite and montmorillonite. The adsorption amount of both surfactants on montmorillonite was much higher than on kaolinite, which was related to the nature of the clays. Although the molar adsorption amount of both surfactants on the same clay were almost identical, there existed some differences in the microstructure of adsorption layer revealed by X-ray diffraction experiments. (C) 2007 Elsevier B.V. All rights reserved.