Electrokinetic sonic amplitude measurement of concentrated alumina suspensions: Effect of electrosteric stabilization

Abstract

This paper describes a convenient and rapid colloidal measuring process of electrokinetic (ζ-potential, ESA signal) properties of the relatively concentrated aqueous suspensions of a submicron -αAl2O 3 powder with the anionic polyelectrolyte (Dolapix CE64) dispersant by applying of an advanced electrokinetic sonic amplitude "ESA" technique without dilution. In addition to ESA measurement, the following measurements were also applied: the viscosity, sedimentation, Bingham yield value and prticle size distribution. Very good agreement is observed from the relationship between the electrokinetic (ζ, ESA) values, the viscosity and its pH dependence for each concentrated α-Al2O3 suspension with different amounts of dispersant. The results indicate that the amount of 0.4 mass% Dolapix CE64 is the optimum amount of dispersant that can cause electrosteric effect and decreases mean (d50) particle size of different concentrated (2 vol% and 45.68 vol%) α-Al2O 3 suspensions near to the original size. Finally, the study illustrates that Dolapix CE64 is an effective dispersant at all solid loading conditions. ©2008 The Ceramic Society of Japan. All rights reserved.