Effect of acids and bases on electrophoretic deposition of alumina and zirconia particles in 2-propanol

The effects of acids (monochloroacetic, dichloracetic, trichloroacetic and sulfuric acids) and bases (diethanolamine, triethanolamine, piperidine) on electrophoretic mobility and electrophoretic deposition (EPD) of particles of amphoteric Al2O3 and ZrO2 in anhydrous 2-propanol were studied. It was found that the ζ-potential of Al2O3 and ZrO2 particles had in acidic and alkaline 2-propanol media opposite charge to that in aqueous medium. This phenomenon was explained by the low dissociation constants of acids and bases in 2-propanol. This enables electrosteric stabilization of Al2O3 and ZrO2 particles by acid anions and base cations. Similar electrophoretic behaviour of Al2O3 and ZrO2 particles in 2-propanolic dispersions stabilized by MCAA allowed the preparation of compact, regular layered laminates with high cohesion at the interface of layers.