University of Oulu

Hyttinen, N., Elm, J., Malila, J., Calderón, S. M., and Prisle, N. L.: Thermodynamic properties of isoprene- and monoterpene-derived organosulfates estimated with COSMOtherm, Atmos. Chem. Phys., 20, 5679–5696, https://doi.org/10.5194/acp-20-5679-2020, 2020

Thermodynamic properties of isoprene- and monoterpene-derived organosulfates estimated with COSMOtherm

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Author: Hyttinen, Noora1; Elm, Jonas2; Malila, Jussi1;
Organizations: 1Nano and Molecular Systems Research Unit, University of Oulu, P.O. Box 3000, 90014 Oulu, Finland
2Department of Chemistry and iClimate, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 4.9 MB)
Persistent link: http://urn.fi/urn:nbn:fi-fe2020061644588
Language: English
Published: Copernicus Publications, 2020
Publish Date: 2020-06-16
Description:

Abstract

Organosulfates make significant contributions to atmospheric secondary organic aerosol (SOA), but little is known about the thermodynamic properties of atmospherically relevant organosulfates. We have used the COSMOtherm program to calculate both the gas- and condensed-phase properties of previously identified atmospherically relevant monoterpene- and isoprene-derived organosulfates. Properties include solubilities, activities and saturation vapor pressures, which are critical to the aerosol-phase stability and atmospheric impact of organosulfate SOA. Based on the estimated saturation vapor pressures, the organosulfates of this study can all be categorized as semi-volatile or low-volatile, with saturation vapor pressures 4 to 8 orders of magnitude lower than that of sulfuric acid. The estimated pKa values of all the organosulfates indicate a high degree of dissociation in water, leading in turn to high dissociation-corrected solubilities. In aqueous mixtures with inorganic sulfate, COSMOtherm predicts a salting-out of both the organosulfates and their sodium salts from inorganic co-solutes. The salting-out effect of ammonium sulfate (less acidic) is stronger than of ammonium bisulfate (more acidic). Finally, COSMOtherm predicts liquid–liquid-phase separation in systems containing water and monoterpene-derived organosulfates. The COSMOtherm-estimated properties support the observed stability of organosulfates as SOA constituents and their long-range transport in the atmosphere but also show significant variation between specific compounds and ambient conditions.

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Series: Atmospheric chemistry and physics
ISSN: 1680-7316
ISSN-E: 1680-7324
ISSN-L: 1680-7316
Volume: 20
Pages: 5679 - 5696
DOI: 10.5194/acp-20-5679-2020
OADOI: https://oadoi.org/10.5194/acp-20-5679-2020
Type of Publication: A1 Journal article – refereed
Field of Science: 116 Chemical sciences
114 Physical sciences
Subjects:
Funding: This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program, Project SURFACE (grant agreement no. 717022). Nønne L. Prisle, Noora Hyttinen, Jussi Malila, and Silvia M. Calderón also gratefully acknowledge the financial contribution from the Academy of Finland (grant nos. 308238 and 314175). Jonas Elm is grateful for financial support from the Swedish Research Council Formas (project number 2018-01745-COBACCA).
EU Grant Number: (717022) SURFACE - The unexplored world of aerosol surfaces and their impacts.
Academy of Finland Grant Number: 308238
314175
Detailed Information: 308238 (Academy of Finland Funding decision)
314175 (Academy of Finland Funding decision)
Dataset Reference: Supplement
  https://www.atmos-chem-phys.net/20/5679/2020/acp-20-5679-2020-supplement.pdf
Copyright information: © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License.
  https://creativecommons.org/licenses/by/4.0/