Atmospheric Reactivity of Fullerene (C₆₀) Aerosols

Rapid growth and adoption of nanomaterial-based technologies underpin a risk for unaccounted material release to the environment. Carbon-based materials, in particular fullerenes, have been widely proposed for a variety of applications. A quantitative understanding of how they behave is critical for accurate environmental impact assessment. While their aqueous phase reactivity, fate, and transport have been studied for over a decade, aerosol phase reactivity remains unexplored. Here, the transformation of C₆₀, as nanocrystal (nC₆₀) aerosols, is evaluated over a range of simulated atmospheric conditions. Upon exposure to UV light, gas-phase O₃, and ^•OH, nC₆₀ is readily oxidized. This reaction pathway is likely limited by diffusion of oxidants within/through the nC₆₀ aerosol. Further, gas-phase oxidation induces disorder in the crystal structure without affecting aerosol (aggregate) size. Loss of crystallinity suggests aged nC₆₀ aerosols will be less effective ice nuclei, but an increase in surface oxidation will improve their cloud condensation nuclei ability.