Dispersion Properties of BaTiO ₃ Colloids with Amphoteric Polyelectrolytes

Abstract

An amphoteric water‐soluble copolymer, i.e., poly(acrylamide/(α‐ N,N ‐dimethyl‐ N ‐acryloyloxyethyl) ammonium ethanate) (PAAM/DAAE), was evaluated as a novel dispersant for aqueous BaTiO 3 (BT) slurries. The dispersing property of this copolymer was examined by means of rheology, sedimentation, particle size, green density, zeta potential, and leached Ba 2+ concentration measurements. The results indicate that PAAM/DAAE could reduce the viscosity of slurries greatly, cause BT particle sizes to shift to smaller values, and make green compacts more consolidated. Compared with a commercial dispersant, ammonium salt of poly(methacrylic acid) (PMAA‐NH 4 ), it is as effective or even better in preparing stabilized suspensions. More importantly, PAAM/DAAE could lessen the leached Ba 2+ concentration. This is related to the adsorption behavior of this copolymer onto BT particles, and the interaction between the adsorbed dispersant and dissolved barium ions.