Suspension stability and consolidation behavior of ultrafine BaTiO3 particles in nonazeotropic solvent system

The effects of nonazeotropic toluene/ethanol and toluene/n-butanol solvents on the suspension stability and consolidation behavior of the 100 nm BaTiO3 particulate suspensions were investigated. The BaTiO3 suspensions showed a similar level of dispersion stability in both solvent mixtures. However, the BaTiO3 suspension prepared in the toluene/n-butanol solvent yielded a better green microstructure than that in the toluene/ethanol solvent, which was indicated by the higher packing density and homogeneity of the suspension prepared in the toluene/n-butanol solvent. The inconsistency between the suspension stability and green-body properties was attributed to the physicochemical properties of solvent mixtures such as composition and different vapor pressure. The mixing of n-butanol having low vapor pressure into toluene facilitated particle rearrangement along the solvent flow during casting and drying, thus developing a more uniform and homogeneous microstructure.