Aging of soot by interaction with organic compounds

Atmospheric aerosols have been known to act as cloud condensation nuclei (CCN) and can indirectly affect the global radiation balance through cloud formation. Soot particles are an important category of atmospheric aerosol constituents, but the hydrophobic nature of fresh soot likely prohibits them from acting as CCN. In the atmosphere soot is expected to experience aging through contacting with oxygenated organic compounds to become hydrophilic enough to promote water uptake. In this study we have measured the interaction between a number of carboxylic acids and soot from different fuel sources. We will characterize the heterogeneous uptake and discuss its possible mechanism. Atmospheric implications from our findings will be discussed.