Interaction between Dissolved Ba2+ and PAA‐NH4 Dispersant in Aqueous Barium Titanate Suspensions

Abstract

The interaction between dissolved Ba2+ and dissociated ammonium salt of poly(acrylic acid) (PAA‐NH4) in aqueous suspension has been studied. The dissolved Ba2+ causes flocculation of dissociated PAA‐NH4, thus degrading its dispersing effectiveness in aqueous BaTiO3 suspensions. The concentration of PAA‐NH4 required to stabilize aqueous BaTiO3 suspension increases with increasing Ba2+ concentration at a given pH. A stability map, which is determined by a rheological study, is constructed to describe the amount of PAA‐NH4 required to have well‐dispersed aqueous BaTiO3 suspensions as a function of Ba2+ concentrations at different pH values.