Rheological Properties and Pressure Filtration of In2O3-SnO2 Suspensions

A polyacrylic ammonium (PAA) of molecular weight 10000 was used as a dispersant of aqueous suspensions for submicrometer-sized In2O3(90mass%)-SnO2(10mass%) powder with an isoelectric point pH 2.5. The adsorption of PAA on the particle surfaces at pH 9-10 approached a saturated value of 0.3-0.4mg/m2 at about 1.0mg/m2 of PAA addition. The apparent viscosity and the pressure filtration rate of suspensions with 35vol% solid, and density of the consolidated powder compacts were closely related to the relative amounts of adsorbed PAA chains and free PAA chains. A well-dispersed suspension, showing the lowest viscosity, was densely consolidated by filtration under a pressure of 196kPa.