Dispersion of Barium Titanate in Aqueous media and Its Influence on Green Microstructure

Abstract

Various processing parameters affecting aqueous BaTiO3 tape casting were investigated in order to fabricate homogeneous green tapes by controlling interparticle forces between colloidal BaTiO3 particles. The dispersion properties of aqueous BaTiO3 suspensions were characterized by electrokinetic sonic amplitude(ESA), the agglomerates size, the amount of Ba2+ dissolution, polymer adsorption and rheological measurements. The role of electroacoustic analysis in aqueous BaTiO3 tape casting will be given both for a characterization and process control applications. Some issues which will be considered include measurements in solids loading concentrations, amount of Ba2+ dissolution and reprecipitation from/on BaTiO3, background electrolyte contributions, and the addition of dispersant and binder. The adsorption characteristics and Ba2+ dissolution of BaTiO3 suspensions were correlated with the dispersion stability of BaTiO3 and green microstructure. Green tapes produced by aqueous tape casting were evaluated in terms of physicochemical property of 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.