Abstract
The interaction between dissolved Ba 2+ and dissociated ammonium salt of poly(acrylic acid) (PAA-NH 4 ) in aqueous suspension has been studied. The dissolved Ba 2+ causes flocculation of dissociated PAA-NH 4 , thus degrading its dispersing effectiveness in aqueous BaTiO 3 suspensions. The concentration of PAA-NH 4 required to stabilize aqueous BaTiO 3 suspension increases with increasing Ba 2+ concentration at a given pH. A stability map, which is determined by a rheological study, is constructed to describe the amount of PAA-NH 4 required to have well-dispersed aqueous BaTiO 3 suspensions as a function of Ba 2+ concentrations at different pH values.