Stabilization of aqueous BaTiO3 suspensions with ammonium salt of poly(acrylic acid) at various pH values

Ammonium salt of poly(acrylic acid) (PAA-NH4) has been used to stabilize aqueous BaTiO3 suspensions at various pH values. Adsorption of PAA-NH4 causes the zeta potential to become more negative, although this effect becomes less dramatic as the pH increases. The concentration of PAA-NH4 required to stabilize aqueous BaTiO3 suspensions decreases with increasing pH. The critical amount of PAA-NH4 as a function of pH is plotted in a stability map, as determined by adsorption, rheology, and sedimentation studies.