Surface properties of silicon nitride powders

The surface charge densities of silicon nitride powders in NaNO3 solutions of various concentrations were investigated by the potentiometric acid–base titration method. The points of zero charge, pHpzc, of silicon nitride powders were determined by the batch equilibration method. The site-binding model was applied to calculate the intrinsic acidity constants describing association–dissociation of silicon nitride surface groups.