Applications and physicochemical characterization of nanomaterials in environmental, health, and safety studies

As commercially manufactured nanomaterials become more commonplace, they have the potential to enter ecological and biological environments during their lifecycle of production, distribution, use or disposal. Despite rapid advances in the production and application of nanomaterials, little is known about how they may interact with the environment or affect human health. This research investigates an environmental application of nanomaterials and characterizes physicochemical properties of commonly manufactured nanomaterials in environmental, health, and safety studies. Characterization of nanomaterials for applications and environmental health and safety studies is essential in order to understand how physicochemical properties correlate with chemical, ecological, or biological response or lack of response. Full characterization includes determining the bulk (shape, size, phase, electronic structure and crystallinity) and surface (surface area, arrangement of surface atoms, surface electronic structure, surface composition and functionality) properties of nanomaterials. This work investigates the selective catalytic reduction (SCR) of NO2 to N2 and O2 with ammonia on nanocrystalline NaY, Aldrich NaY and nanocrystalline CuY using in situ Fourier transform infrared (FTIR) spectroscopy. The kinetics of SCR were 30% faster on nanocrystalline NaY compared to commercial NaY due to an increase in external surface area and external surface reactivity. Nanocrystalline CuY showed an additional increase in the rate of SCR as well as distinct NO2 and NH3 adsorption sites associated with the copper cation. These superior de-NOx materials could contribute to a cleaner environment.