TY - JOUR
T1 - The Chamber Wall Index for Gas-Wall Interactions in Atmospheric Environmental Enclosures
AU - Brune, William H.
N1 - Funding Information:
I thank Ying Pan, Andrew Lambe, John Crounse, Jordan Krechmer, and Jose Jimenez for helpful conversations, Jena Jenkins and Devin Wang for insights into chamber design, and the anonymous reviewers for their comments. This work was supported by the US National Science Foundation grant AGS-1537009.
Publisher Copyright:
Copyright © 2019 American Chemical Society.
PY - 2019/4/2
Y1 - 2019/4/2
N2 - Secondary organic aerosol (SOA) particles, which are formed and aged in Earth's oxidizing atmosphere, influence climate and human health. Quantifying properties of SOA particles and oxidized organic compounds (OVOCs) requires controlled experiments in enclosures, but enclosures have walls that can alter the chemistry. Comparing wall effects for widely used large environmental chambers (ECs) and portable oxidative flow reactors (OFRs) is difficult. In this work, the Chamber Wall Index (CWI) is developed as the minimum ratio of the initial wall uptake time constant divided by the enclosure residence time. This index demonstrates that walls alter the chemistry less in OFRs than in ECs, due primarily to shorter residence times. Much shorter residence times may not be feasible because oxidation chemistry and microphysics need time to produce atmospherically relevant SOA and OVOCs. While all current OFRs have wall effects, it may be possible to develop a "wall-less" OFR.
AB - Secondary organic aerosol (SOA) particles, which are formed and aged in Earth's oxidizing atmosphere, influence climate and human health. Quantifying properties of SOA particles and oxidized organic compounds (OVOCs) requires controlled experiments in enclosures, but enclosures have walls that can alter the chemistry. Comparing wall effects for widely used large environmental chambers (ECs) and portable oxidative flow reactors (OFRs) is difficult. In this work, the Chamber Wall Index (CWI) is developed as the minimum ratio of the initial wall uptake time constant divided by the enclosure residence time. This index demonstrates that walls alter the chemistry less in OFRs than in ECs, due primarily to shorter residence times. Much shorter residence times may not be feasible because oxidation chemistry and microphysics need time to produce atmospherically relevant SOA and OVOCs. While all current OFRs have wall effects, it may be possible to develop a "wall-less" OFR.
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U2 - 10.1021/acs.est.8b06260
DO - 10.1021/acs.est.8b06260
M3 - Article
C2 - 30840441
AN - SCOPUS:85063105424
SN - 0013-936X
VL - 53
SP - 3645
EP - 3652
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 7
ER -