Zeta potential of various oxide particles and the charging mechanism

The charging behavior of various oxide particles was investigated using the zeta potential, which is affected by the electronegativity of the metal io n in an oxide and the properties of the solvents. Acetone, methylethylketon e, cyclohexanone, ethanol (EtOH), 1-propanol (1-PrOH) and 1-butanol (1-BuOH ) were used for the bath. In the case of the I-2-added ketone bath, the Hion concentration increased with increasing I-2 content. The zeta potential of the various oxide particles was changed to positive. The zeta potential of the oxides was large in the high H+ ion concentration bath. Accordingly , the positive charged oxide particles were attributed to the adsorption of H+ ion onto the particles. In the case of alcohol, included H2O generates H+ and OH- by electrolytic dissociation. Therefore, the zeta potential beco mes large in the case when the electronegativity of the metal ion in oxide is low, and the H+ ion behaves as a potential determining ion.