Effect of dispersants on surface chemical properties of nano-zirconia suspensions

Surface charge and particle dispersion of zirconia in aqueous suspension with addition of different dispersants, such as ammonium polymethacrylic acid (Darvan C), polyethylene imine (PEI) and diammonium citrate (DAC) were investigated by measuring its zeta potential and particle size. It was found that the zero point of charges (zpc) of 3Y-TZP powder was determined to be pHzpc=6, surface charge of zirconia powder changed significantly and zpc shifted under different dispersion conditions. Zirconia particle was in monodispersed state far from zpc, while in a certain degree of agglomeration in the vicinity of zpc. The study illustrates how zeta potential and effective particle size can be utilized in the investigation and optimization of the properties of ceramic suspensions. ©