Determination of Particle Size Distribution by Laser Diffraction of Doped-CeO_2 Powder Suspensions:Effect of Suspension Stability and Sonication

摘要

The particle size distributions (PSDs) of metal oxide powders are often determined by analyzing suspensions of powders using laser diffraction (e.g.Malvern Master-Sizer 2000).Particle agglomeration can effectively bias the resulting distribution towards "unrealistic" particle sizes.Solutions to avoid this problem must be found if a particle distribution based on the elemental or primary particle sizes is desired. In this work,the particle size distribution of doped-CeO_2 powders was studied.These powders show a crystalline single phase structure of controlled stoichiometry as determined by X-ray diffraction and ICP analysis.The apparent size distribution was found to be a strong function of suspension stability.Dispersant agents (PBTCA and phosphonoacetic acid) and suspension pH affected stability as characterized by zeta potential measurements.Sonication of the suspensions further enhanced particle de-agglomeration.Finally,only the combined effect of a dispersant agent,pH adjustment of the suspension and sonication provided a primary particle size distribution.The results presented in this work can be used in the analysis of similar ceramic powders in which strong particle agglomeration is present.