AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Atmospheric Aging of Fullerene Nanoparticles
DHRUV MITROO, Peter Colletti, Michael Walker, Jiewei Wu, John Fortner, Brent Williams, Washington University in St. Louis
Abstract Number: 308 Working Group: Carbonaceous Aerosols in the Atmosphere
Abstract Rapid growth of industrial scale nanomaterial production underpins rising concerns regarding the eventual fate and possible inadvertent impacts of these materials on the health and function of natural systems. While there have been a number of studies regarding the environmental chemistry of engineered nanomaterials in water and soils, the role of atmospheric processes and chemistries of such materials has not been thoroughly investigated. Carbon based nanoscale materials, in particular fullerenes and carbon nanotubes, have been widely proposed for a variety of applications and are now being produced at the industrial scale. An understanding of how such materials behave once released in the atmosphere (or exposed to atmospheric processes) is critical for accurate risk assessments and effective management of waste disposal practices and release scenarios. To date, studies regarding fullerene environmental fate, transport, and effects have centered on aqueous available forms, either as aqueous stabilized nanoscale colloids (termed nC$_(60) or nanoC$_(60)) or with pre-characterized, water-soluble derivatives (such as hydroxylated fullerenes or other commercially available materials). While insightful, the vast majority of these studies fail to incorporate the significant potential for a number of naturally occurring atmospheric-based (photo)reaction scenarios, which could fundamentally change fullerene physicochemical behavior and environmental impact (i.e. altering aggregate stability, monomer solubility, and effective toxicity).
To systematically evaluate atmospheric nC$_(60) (photo)reactions, we developed a setup for introducing an aerosol stream of pure nC$_(60) into the Potential Aerosol Mass (PAM) reactor for oxidative aging studies ranging from OH-dominated to O$_3-dominated regimes under UV irradiation. Chemical and physical identification of nC$_(60) and its oxidation reaction products, as well as preliminary kinetics, are presented for various model atmospheric aging conditions.