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

The electrokinetic and the adsorption characteristics of silica, titanium o xide, aluminium and ferric hydroxides were studied as a function of pH on t he background of 1:1 electrolytes. Surface reaction constants and ion adsor ption potentials were calculated within the framework of 2-pK model. The ox ide Si-, Al-, Ti- and Fe-oxo-layers were synthesized onto silica substrates by the molecular chemical modification from the gas phase. The surface par ameters of oxide nanostructures were compared with characteristics of subst rate and corresponded (hydr)oxides. It was shown that the properties of oxi de 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.