Effect of zeta potential on the stabilization of zirconia microparticles suspension using nanoparticle halo mechanism

In many industrial processes, in the middle stages of production, the final product or residuals contains aqueous suspensions. The instability of suspensions is one of the main challenges towards the mentioned processes. Present study is the result of an experimental investigation that analyzed the effect of Silica nanoparticles on the stabilization of Zirconia microsuspension. The effect of Zeta potentialof micro and nanoparticles on theperformance of the stabilization method by generation of nanoparticle halos were studied experimentally. The turbidity of microparticle suspension, was measured before and after addition of nanoparticles at different PH values. The results of experiments shows that for all PH values, the addition of nanoparticles increases the stability of the suspension.The achieved stability is due to the formation of nanoparticle halos that has been observed using a scanning electron microscope (SEM). Nanoparticle halos decreases the Wan der Waals attractive force and increases the electrostatic charge of microparticles and consequently increases the stability of the resultant suspension.The strength of the stability varies with PH values due to the difference in the electric charge. The maximum stability occurs at the isoelectric point of Zirconia microparticles. When microparticles have relatively low electric charge, the potential sink around them are deeper and thus more nanoparticles form halos. The minimum stabilization also occurs when the microparticles have relatively high electric charge that increases the repulsive force between micro and nanoparticles.