REACTIVE UPTAKE AND HYDRATION EXPERIMENTS ON AMORPHOUS-CARBON TREATEDWITH NO2, SO2, O-3, HNO3, AND H2SO4

The reactivity and hydration properties of amorphous carbon were studi ed in a low-pressure Knudsen cell reactor at room temperature (298 K). Reactions of NO2 (gamma = 0.11 +/- 0.04) and HNO3 (gamma = 0.038 +/- 0.008) were observed and may be important for nitrogen partitioning in the atmosphere. Water uptake was measured before and after exposure t o various gases. Treating the amorphous carbon with NO2 and O-3 does n ot alter the H2O uptake, while treatment with SO2, HNO3, and H2SO4 Sig nificantly increases the H2O uptake. The experimental results support current assumptions in jet aircraft plume models that sulfuric acid co ndensation is involved in the activation of soot particles as condensa tion nuclei.