skip to main content

SciTech ConnectSciTech Connect

Title: Formation and aging of secondary organic aerosol from toluene: changes in chemical composition, volatility, and hygroscopicity

Secondary organic aerosol (SOA) is transformed after its initial formation, but this chemical aging of SOA is poorly understood. Experiments were conducted in the Carnegie Mellon environmental chamber to form secondary organic aerosol (SOA) from the photo-oxidation of toluene and other small aromatic volatile organic compounds (VOCs) in the presence of NOx under different oxidizing conditions. The effects of the oxidizing condition on organic aerosol (OA) composition, mass yield, volatility, and hygroscopicity were explored. Higher exposure to the hydroxyl radical resulted in different OA composition, average carbon oxidation state (OSc), and mass yield. The OA oxidation state generally increased during photo-oxidation, and the final OA OSc ranged from -0.29 to 0.16 in the performed experiments. The volatility of OA formed in these different experiments varied by as much as a factor of 30, demonstrating that the OA formed under different oxidizing conditions can have a significantly different saturation concentration. There was no clear correlation between hygroscopicity and oxidation state for this relatively hygroscopic SOA.
 [1] ;  [2] ;  [3] ;  [3] ;  [2] ;  [4]
  1. Univ. of Texas, Austin, TX (United States); Carnegie Mellon Univ., Pittsburgh, PA (United States)
  2. Carnegie Mellon Univ., Pittsburgh, PA (United States)
  3. Georgia Inst. of Technology, Atlanta, GA (United States)
  4. Carnegie Mellon Univ., Pittsburgh, PA (United States); Univ. of Patras, Patras (Greece)
Publication Date:
OSTI Identifier:
Grant/Contract Number:
Published Article
Journal Name:
Atmospheric Chemistry and Physics (Online)
Additional Journal Information:
Journal Name: Atmospheric Chemistry and Physics (Online); Journal Volume: 15; Journal Issue: 14; Journal ID: ISSN 1680-7324
European Geosciences Union
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23); EPA STAR Program; National Science Foundation (NSF). Major Research Instrumentation; Wallace Research Foundation
Country of Publication: