The compaction of soot particles generated by spark discharge in the propene ozonolysis system

The compaction of soot aggregates generated by spark discharge is reported in the propene ozonolysis experiment. Since propene is not an organic aerosol precursor, the compaction cannot be explained by an earlier hypothesis attributing the compaction to the capillary forces of condensed organic matter in the small angle cavities of the aggregates [Saathoff, Naumann et al. (2003). Coating of soot and (NH4)2 SO4 particles by ozonolysis products of alpha-pinene. Journal of Aerosol Science, 34, 1297–1321]. Several species among the gas-phase products from propene ozonolysis are proposed to contribute to the structural change of soot particles. As the compaction would directly change the morphology and the size distribution of soot particles, it is expected to induce important changes to the soot particles’ physical and chemical properties, which in turn would have significant atmospheric implications.