Dispersion studies of sub-micron zirconia using Dolapix CE 64

In this paper, the effect of a commercial carbonic acid based polyelectrolyte, Dolapix CE 64, on stabilization of sub-micron size zirconia suspension is reported. The effect of pH, concentration of polyelectrolyte and solids loading on the dispersion of zirconia has been evaluated by zeta-potential studies, sedimentation, capillary suction time (CST) measurements and viscosity measurements. Zeta-potential measurements showed that adsorption of polyelectrolyte shifted the iso-electric point (IEP) of zirconia from 5.4 to 3.3 and made the surface more electronegative indicating strong interaction. Sedimentation tests showed that zirconia suspensions were stable up to 24 h in alkaline pH range. Capillary suction time measurements and viscosity tests revealed that about 8 mg of dispersant per gram of zirconia was the optimum dosage and solids loading of about 60 wt% could be achieved at pH 8.