Soluble nanoparticles (NPs) of metallic and mineral oxide constituents are a class of nanomaterials now widely produced for commercial purposes. Despite their significance, the transformations controlling dissolution rates are not well understood. Dissolution rates of these NPs are likely to be affected by interlinked reactions including aggregation, deposition, and metal complexation by ligands. Synthetic surface coatings, often used to stabilize NPs and reduce aggregation, will also affect dissolution. Each of these processes will influence NP persistence and exposure in the environment and may do so in synergistic or antagonistic ways that determine subsequent reactivity, bioavailability, and toxicity. In this project the PIs seek to understand how two critical processes affecting NP transport and fate aggregation and dissolution combine to regulate the persistence and exposure of NPs through impacts on metal speciation and availability to target organisms. The work will investigate at a fundamental level the individual and collective effects of dissolution, aggregation, metal ion complexation and uptake resulting from NP exposure. In particular, the interactions between the surfactant coatings and natural organic ligands will be examined. The outcome of this work will be disseminated through scientific publications and conferences. Broader outreach to the public will occur through existing programs including a nationwide nanoscience education initiative with science museums and a local science and engineering education program for elementary school girls. The proposed work will directly support the education of graduate, undergraduate, and high school student researchers.
