OXIDE ELECTROLYTE INTERFACE - INTERPRETATION OF SUPPORTING ELECTROLYTE ADSORPTION DATA

Zeta potentials of silica and alumina in aqueous NaCl solutions can be estimated from sigma0 surface charge densities and the adsorption of supporting electrolyte using one value of x slipping plane distance in dependent of pH and ionic strength when a proper correction is introdu ced into apparent sigma0 directly calculated from titration data. The nature of the counterion strongly affects the adsorption data. Adsorpt ion on silica increases from Li to Cs but due to a parallel increase o f sigma0, zeta is independent of the cation. Contrary the adsorption o n alumina decreases froin Li to Cs while sigma0 and negative zeta pote ntials are little affected by the counterion.