Dispersion of Barium Titanate in Aqueous media and its influence on microstructural evolution

Abstract

The dispersion properties of aqueous BaTiO3 suspensions for fabricating homogeneous green tapes were characterized by measuring the electrokinetic sonic amplitude (ESA), the agglomerate size, the amount of Ba2+ dissolution, polymer adsorption and rheology. The role of electroacoustic analysis in aqueous BaTiO3 tape casting will be given both for characterization and process control applications. Some issues which will be considered include measurements in solids loading concentrations, amount of Ba2+ dissolution and reprecipitation from/onto BaTiO3, background electrolyte contributions, and the addition of dispersant and binder. The additive adsorption characteristics and Ba2+ dissolution were correlated with the dispersion stability and green microstructure. Green tapes produced by aqueous tape casting were evaluated in terms of the physicochemical property of the BaTiO3 surface, particle packing characteristics, lamination performance, and binder burnout. Attempts were made to draw a correlation between green tape characteristics and the slurry characteristics.