Research

Role of Material Properties and Environmental Conditions on Nanoparticle Aggregation and Dissolution- FT-1

Research team:
Arturo Keller, Dongxu Zhou

The overall goal of this project is to understand the mechanisms and environmental factors that control aggregation and dissolution of nanoparticles (NPs). NP aggregation is important because it determines their mobility in the environment, which is key for determining their bioavailability. The aggregation state of the NPs will affect how long they may keep suspended in water column, and at what size they will interact with aquatic organisms.

TEM image of Meliorum ZnO nanoparticle

For several NPs, their dissolution and shedding of ions can be an important factor determining their toxicity and the ultimate fate of the NP. Specifically, the aims of the project are to: (1) determine the effect of solution chemistry on NP aggregation rates; (2) correlate NP properties (e.g., composition, size, morphology, crystal structure, and capping agents) and their tendency to aggregate or remain stable; (3) study the interactions between NPs and suspended particles; and (4) determine the rate of dissolution of metal and metal oxide NPs in natural waters. We work with metal (Ag, Pd and Pt) and metal oxide (TiO2, CeO2, ZnO, CuO and Fe2O3) NPs provided by Theme 1.

Overall, the outcome of this project is contributing to (1) identify critical environmental and material parameters affecting NP aggregation, which will help to predict the behavior of these NPs when released in the environment; (2) provide detailed information to ecotoxicologists in Themes 4 and 5 regarding (a) particle size and aggregation/disaggregation process they should expect when conducting toxicology studies; (b) rate of NP dissolution and availability of dissolved metal ions; and (c) improvements to the dispersion protocols of these metal and metal oxide NPs. In addition, the experimental aggregation data will be important input and validation components for the environmental modeling endeavor of Theme 6.