Experimental study on zeta potential and streaming potential of advanced ceramic powders

Zeta potential as measured with the electrokinetic sonic amplitude (ESA) method has been compared to streaming potential as measured with the particle charge detection (PCD) method. The measurements have been carried out on identical suspensions of α-Al2O3, SiC and Si3N4 with a solids volume fraction of 1% and 10%. Zeta potential and streaming potential are related by a linear function. The correlation coefficients for this relationship are better than 0.99 for the suspensions with 1% solids loading. For the suspensions with 10% solids loading, correlation coefficients are slightly lower due to the influence of increasing viscosity. Regardless of lower correlation at the higher solids loading, the isoelectric pH is constant within the limits of accuracy of the pH measurements.