Effects of Solids Loading, pH, and Polyelectrolyte Addition on the Stabilization of Concentrated Aqueous BaTiO 3 Suspensions

Colloidal stability of concentrated aqueous BaTiO 3 suspensions with ammonium salts of poly(acrylic acid) (PAA‐NH 4 ) and poly(methacrylic acid) (PMAA‐NH 4 ) as a function of pH and solids loading is investigated. For suspensions with solids loading less than 40 vol%, the required polyelectrolyte concentration to stabilize aqueous BaTiO 3 suspensions decreases with increasing pH, but remains relatively unchanged with increasing solids loading. As the solids loading continuously increases (e.g., >50 vol%), the required amount of polyelectrolyte increases, but exhibits a minimum at pH ∼ 9.2. The critical amount of polyelectrolyte needed to achieve colloidal stability of aqueous BaTiO 3 suspensions as a function of pH and solids loading is summarized in a three‐dimensional stability map.