Calorimetric investigations of gemini and conventional cationic surfactants at two silica-solution interfaces

The importance of calorimetric methods in the study of colloidal phenomena is illustrated here by analysis of the enthalpies of adsorption, at 35 degr eesC, of two gemini and conventional cationic surfactants (12-2-12 and DTAB , respectively) on the surfaces of two silicas with different chemical prop erties. The values of the differential molar enthalpies of adsorption, corr ected for the contribution of the dilution of the surfactant in solution, a llow precise description of the adsorption process of the surfactants at th e solid-solution interface. (C) 2001 Published by Elsevier Science B.V.