Dispersion properties of BaTi4O9/Ba2Ti9O20 colloids with amphoteric polyelectrolytes

An amphoteric water-soluble copolymer, i.e., polyacrylamide/(α-N,N-dimethyl-N-(3-(β-carboxylate)acrylamino)propyl) ammonium ethanate (PAM/DAE) was synthesized and used as a dispersion agent for BaTi4O9/Ba2Ti9O20 (BT4/B2T9) particles. PAM/DAE was prepared from acrylamide and (α-N,N-dimethyl-N-(3-(β-carboxylate)acrylamino)propyl) ammonium ethanate in a basic condition through a free radical polymerization. The dispersing property of this copolymer was examined by means of rheology, particle size, and leached Ba2+ concentration measurements. The results indicate that PAM/DAE could reduce the viscosity of slurries greatly, and cause BT4/B2T9 particle sizes a shift to smaller values. Compared with a commercial dispersant, ammonium salt of poly(methacrylic acid) (PMAA-NH4), PAM/DAE is as effective in preparing dispersed suspensions. More importantly, PAM/DAE could lessen the leached Ba2+ concentration.