| Title: | "Secondary Organic Aerosol (SOA) from Nitrate Radical Oxidation of Monoterpenes: Effects of Temperature, Dilution, and Humidity on Aerosol Formation, Mixing, and Evaporation" |
| Author(s): | Boyd CM; Nah T; Xu L; Berkemeier T; Ng NL; |
| Address: | "School of Chemical and Biomolecular Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States. School of Earth and Atmospheric Sciences, Georgia Institute of Technology , Atlanta, Georgia 30332, United States" |
| ISSN/ISBN: | 1520-5851 (Electronic) 0013-936X (Linking) |
| Abstract: | "Nitrate radical (NO(3)) oxidation of biogenic volatile organic compounds (BVOC) is important for nighttime secondary organic aerosol (SOA) formation. SOA produced at night may evaporate the following morning due to increasing temperatures or dilution of semivolatile compounds. We isothermally dilute the oxidation products from the limonene+NO(3) reaction at 25 degrees C and observe negligible evaporation of organic aerosol via dilution. The SOA yields from limonene+NO(3) are approximately constant ( approximately 174%) at 25 degrees C and range from 81 to 148% at 40 degrees C. Based on the difference in yields between the two temperatures, we calculated an effective enthalpy of vaporization of 117-237 kJ mol(-1). The aerosol yields at 40 degrees C can be as much as 50% lower compared to 25 degrees C. However, when aerosol formed at 25 degrees C is heated to 40 degrees C, only about 20% of the aerosol evaporates, which could indicate a resistance to aerosol evaporation. To better understand this, we probe the possibility that SOA from limonene+NO(3) and beta-pinene+NO(3) reactions is highly viscous. We demonstrate that particle morphology and evaporation is dependent on whether SOA from limonene is formed before or during the formation of SOA from beta-pinene. This difference in particle morphology is present even at high relative humidity ( approximately 70%)" |
| Keywords: | *Aerosols *Air Pollutants Humidity *Monoterpenes Temperature; |
| Notes: | "MedlineBoyd, Christopher M Nah, Theodora Xu, Lu Berkemeier, Thomas Ng, Nga Lee eng 2017/06/20 Environ Sci Technol. 2017 Jul 18; 51(14):7831-7841. doi: 10.1021/acs.est.7b01460. Epub 2017 Jul 6" |
