Electrokinetic and adsorption characteristics of (hydr)oxides and oxide nanostructures in 1:1 electrolytes

The electrokinetic and the adsorption characteristics of silica, titanium oxide, aluminium and ferric hydroxides were studied as a function of pH on the background of 1:1 electrolytes. Surface reaction constants and ion adsorption potentials were calculated within the framework of 2-pK model. The oxide Si-, Al-, Ti- and Fe-oxo-layers were synthesized onto silica substrates by the molecular chemical modification from the gas phase. The surface parameters of oxide nanostructures were compared with characteristics of substrate and corresponded (hydr)oxides. It was shown that the properties of oxide nanostructures are not dependent on the type of silica substrate. It was also obtained that the isoelectric point (IEP) of oxide nanostructure and the corresponding metal (hydr)oxide have different values except for Al. (C) 2001 Elsevier Science B.V. All rights reserved.