Elias Nakouzi

Pauling Fellow
Pacific Northwest National Laboratory

Title: “Direct observation of nanoparticle-solution interfaces and interactions help predict the outcomes of aggregation”

Abstract: One of the challenges of modern physical and materials chemistry is to build a predictive understanding of nanomaterial growth, attachment, aggregation, and assembly in solution. Two key knowledge gaps towards this goal are: 1) visualizing crystal-solution interfaces that create ion distributions and chemical potential gradients, and 2) measuring the contribution and scaling of various inter-particle forces. In this context, we investigated the solution structure at the boehmite–aqueous interface using a recently developed 3D atomic force microscopy capability. Our data show structuring of water layers extending to ~1 nm from the surface, with subnanometer features templated by the underlying crystal lattice–which is validated by molecular dynamics simulations. These results are complemented by measurements of the interaction potentials using direct observations of particle attachment from liquid phase electron microscopy. Our studies provide a platform for understanding the role of crystal interfaces and interactions in determining the pathways of nanoparticles in solution.