Abstract: Concentrated Y-TZP aqueous suspensions(～50vol%) were prepared by employing poly acrylate(NaPAA and NH₄PAA) as dispersant. Zeta potential
of the suspensions was displaced to pH 2.2 by the adsorption of RCOO^- group released by PAA salts in aqueous solution. The viscosity was at its lowest
point when NaPAA content was 1.8 wt%. Solids loading and particle size significantly influenced the rheology of Y-TZP suspensions. Concentrated
suspensions(>35vol%)were typical Bingham fluid, second newtonian plateau was observed at high shear rate. Plastic viscosity and yield value
demonstrated sharp ascension in 50 vol% suspension under a shear rate of 20s^-1. The appropriate particle size for preparing high solids loading
Y-TZP suspensions was about 350 nm.

Key words: zirconia, suspensions, rheology, viscosity, dispersant