UC Berkeley

The reaction of closed shell Cl2 molecules with sub-micron droplets composed of unsaturated molecules, oleic acid (OA), linoleic acid (LA), linolenic acid (LNA), or squalene (Sqe), are investigated in an atmospheric pressure flow tube reactor in conjunction with a vacuum ultraviolet photoionization aerosol mass spectrometer and a scanning mobility particle sizer. Cl2 is found to react with all particles, and the reactive uptake coefficients depend on the number of unsaturated reaction sites, e.g., γCl2Sqe = (0.66 ± 0.03) × 10-4 versus γCl2OA = (0.23 ± 0.01) × 10-4. In addition, the chemical evolution of squalene and its chlorinated products reveal that the reaction becomes slower for higher chlorinated products.