NANOSCALE CLUSTERS AND URANIUM SOLUBILITY

Nanoscale cage clusters assembled from uranyl ions have been shown to self-assemble in aqueous solution under ambient conditions. This occurs under laboratory conditions when uranyl ions are combined with peroxide ligands, or potentially in natural systems where peroxide is produced by the alpha-radiolysis of water. Where uranyl nanoclusters occur in a system containing uranyl minerals, the solubility of the minerals will not only be impacted by the aqueous speciation of uranyl in solution, but also by the properties of the nanoclusters. This presentation will focus on the formation, persistence, aggregation, and properties of selected uranyl nanoclusters in aqueous solution. We demonstrate that incorporation of uranyl into nanoclusters in solutions containing various uranyl minerals increases the uranium concentration in solution by orders of magnitude, in comparison to systems lacking the nanoclusters.