The maximum solid loading and viscosity estimation of ultra-fine ZnO-Al_2O_3 mixed powders aqueous suspensions

摘要

The rheological behavior of sub-micron zinc oxide and alumina mixture powders aqueous suspension has been investigated over a wide range of volumetric solids loading (Φ = 0.2-0.55), in which polyacrylic acid (PAA) was used as a dispersant. The dependence of relative viscosity (η_r)-solids loading (Φ) determined experimentally was compared with models. The experimental results showed that the suspension apparent viscosity (η) reached a minimum as the dispersant addition reached 0.2 wt%, the viscosity increased with the solids loading and the rheological behavior of the suspension was content basically with the model proposed by Liu. From η_r-Φ relationship the maximum solid loading (Φ_M) was estimated to be 0.55, which was in accord with our experimental results.