Abstract View
Surface Tension Depression of Aqueous-Phase Glyoxal/Ammonium Sulfate Hanging-Droplet Aerosol Mimics via Direct Photochemistry
Daphna Fertil, JOSEPH WOO, Lafayette College
Abstract Number: 280
Working Group: Aerosol Chemistry
Abstract
Carbonyl-containing volatile organic compounds (CVOCs) are present in a wide range of atmospherically relevant contexts and can contribute significant portions of water-soluble organic carbon in aqueous aerosols, forming a variety of heterocyclic and/or oligomeric products under dark conditions. However, condensed-phase chemistry is much less understood, resulting in potential increases and decreases to extent of CVOC oligomerization. This study reports in-situ surface tension measurements of glyoxal/ammonium sulfate hanging-droplet aqueous aerosol mimics, exposed to direct UV-induced photochemistry. While dark chemistry products of glyoxal and ammonium sulfate do not exhibit significant surfactant properties, direct photochemistry results in the immediate formation of products capable of statistically significant surface tension depression. Extent of surface tension depression is measured across multiple bulk-phase concentrations and exposure times, and compared to mimic solution bulk-phase UV/visible absorbance under similar conditions.