EFFECT OF PAA-NH_4 DISPERSANT ON DISPERSIB1LITY OF AQUEOUS Pb(Zr,Ti)O_3 SLURRIES AND PIEZOELECTRIC PROPERTIES OF RESULTANT SINTERED BODIES

摘要

The effect of poly ammonium acrylate (PAA-NH4) dispersant on the dispersibility of Pb(Zr,Ti)O_3 (PZT) slurries and the piezoelectric properties of resultant PZT sintered bodies was investigated for the establishment of environmentally friendly aqueous processing. The dispersion state and viscosity of PAA-NH_4-added PZT aqueous slurries strongly depended on the slurry pH. Well-dispersed PZT slurries with negligibly small Pb~(2+) dissolution were obtained in the alkaline side due to the electrostatic steric hindrance effect of adsorbed polyelectrolyte dispersant molecules with a high dissociation ratio of carboxylic acid groups. The homogeneous dense microstructure and the enhancement of the piezoelectric properties of PZT ceramic bodies were achieved by preparingt'he aqueous PZT slurry with an optimum amount of dispersant.