To characterize the environmental transport and health risks of CeO 2 nanoparticles (NPs), it is important to understand their aggregation behavior. This study investigates the aggregation kinetics of CeO 2 NPs in KCl and CaCl 2 solutions using timeresolved dynamic light scattering (TR-DLS). The initial hydrodynamic radius of CeO 2 NPs measured by DLS was approximately 95 nm. Attachment efficiencies were derived both from aggregation data and predictions based on the Derjaguin-Landau-Verwey- Overbeek (DLVO) theory. The deviations of the DLVO predictions were corrected by employing the extended DLVO (EDLVO) theory. The critical coagulation concentration (CCC) of CeO 2 NPs at pH = 5.6 is approximately 34 mM for KCl and 9.5 mM for CaCl 2. Furthermore, based on the EDLVO theory and the von Smoluchowski's population balance equation, a model accounting for diffusion-limited aggregation (DLA) kinetics was established. For the reactionlimited aggregation (RLA) kinetics, a model that takes fractal geometry into account was established. The models fitted the experimental data well and proved to be useful for predicting the aggregation kinetics of CeO 2 NPs.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics
- Modeling and Simulation
- Materials Science(all)
- Condensed Matter Physics
- Modeling and simulation