ICARUS Chamber Experiment: Caltech Atmospheric Chamber_20150208_METHACROLEIN/Methyl nitrite/10102-44-0_Hydroxyl radical_Ammonium sulfate_RH85%

Goals: This experiment was done to study the Methacrolein high NO2 photooxidation in the presence of fully deliquesced ammonium sulfate (AS) seeds at RH 85%, since the other experiments were done at low RH and without seed particles. The hypothesis is that particle liquid water will decrease SOA formation because water will hydrolyze HMML instead of allowing it to oligomerize on the particle surface. This liquid water is also hypothesized to liberate 2-methylgycleric acid (2MGA) from the aerosol to the gas phase.Summary: Gas-phase 2MGA is significantly enhanced and aerosol mass is significantly decreased compared to the dry experiments.Organization: Caltech Atmospheric Chamber Lab Affiliation: California Institute of Technology, Pasadena, CA Chamber: Near/Far Bag 2012-2015 (Tran)Experiment Category: Gas phase chemical reaction, Aerosol formation Oxidant: Hydroxyl radical Reactants: METHACROLEIN, Methyl nitrite, 10102-44-0 Reaction Type: Photooxidation Relative Humidity: 85 Temperature: 25 Seed Name: Ammonium sulfate Pressure: 750 Torr