Insight into the role of initial concentration and mixing patterns in rapid crystallization outcome: An ethanol-antisolvent crystallization process of precursor for 8YSZ nano-powders

Abstract

A novel precursor of 8YSZ nano-powders was precipitated from aqueous solutions using an antisolvent crystallization technique. Water was used as a solvent and ethanol was used as an antisolvent. During this experiment, the effect of initial concentration and mixing pattern on solid-state properties, such as microstructure particle size, agglomeration, and particle size distribution, of precursors and 8YSZ nano-powders were investigated. A series of analyses of as-obtained precursors and 8YSZ nano-powders showed that the lower initial concentration and injection mixing patterns, which provided a high supersaturation level and a stronger effect of ethanol as a dispersant, resulted in well-dispersed and small-sized powders. Further investigating the sintering and electrical properties of sintered 8YSZ ceramics, it was found that these properties were a strong function of particle sizes changed by various initial concentrations and mixing patterns. The density and conductivity of the sintered ceramics first increased and then decreased with the increasing particle size of 8YSZ nano-powders, which may be because of the as-obtained appropriate particle size (55–60 nm) from the optimal operating parameter (injection mixing patterns with high initial concentration) in favor of preventing grain coarsening in the sintering process. This work showed the potential to prepare the desired solid-state properties of 8YSZ nano-powders by changing operating parameters via an antisolvent crystallization technique.