Rheological properties and pressure filtration of In2O3-SnO2 suspensions

A polyacrylic ammonium (PAA) of molecular weight 10000 was used as a disper sant of aqueous suspensions for submicrometer-sized In2O3 (90 mass%)-SnO2 ( 10 mass%) 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 0.3-0.4 m g/m(2) at about 1.0 mg/m(2) of PAA addition. The apparent viscosity and the pressure filtration rate of suspensions with 35 vol% solid, and density of the consolidated powder compacts were closely related to the relative amou nts of adsorbed PAA chains and free PAA chains. A well-dispersed suspension , showing the lowest viscosity, was densely consolidated by filtration unde r a pressure of 196 kPa.