Effect of Particle Size Distribution on the Accuracy of Electroacoustic Mobilities

Abstract

The measurement of electrokinetic mobilities in concentrated dispersions (>1% v/v) using the electrokinetic sonic amplitude (ESA) technique at a frequency of 1 MHz is considered. The correlation of such measurements to mobilities measured using classical techniques such as microelectrophoresis rests in the theoretical ratio of the high frequency or dynamic mobility (μe) and the electrophoretic mobility (μω). This ratio varies greatly as a function of particle radius at constant frequency. We report an overview of the predictions of the theory of O'Brien (J. Fluid Mech. 1988,190, 71) and the correlation of measurements for both colloidal silica and titania where the particle size distribution..