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| Titel |
Thermodynamics of the formation of sulfuric acid dimers in the binary (H₂SO₄–H₂O) and ternary (H₂SO₄–H₂O–NH₃) system |
| VerfasserIn |
A. Kürten, S. Münch, L. Rondo, F. Bianchi, J. Duplissy, T. Jokinen, H. Junninen, N. Sarnela, S. Schobesberger, M. Simon, M. Sipilä, J. Almeida, A. Amorim, J. Dommen, N. M. Donahue, E. M. Dunne, R. C. Flagan, A. Franchin, J. Kirkby, A. Kupc, V. Makhmutov, T. Petäjä, A. P. Praplan, F. Riccobono, G. Steiner, A. Tomé, G. Tsagkogeorgas, P. E. Wagner, D. Wimmer, U. Baltensperger, M. Kulmala  , D. R. Worsnop, J. Curtius |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 18 ; Nr. 15, no. 18 (2015-09-25), S.10701-10721 |
| Datensatznummer |
250120058
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| Publikation (Nr.) |
 copernicus.org/acp-15-10701-2015.pdf |
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| Zusammenfassung |
| Sulfuric acid is an important gas influencing atmospheric new particle
formation (NPF). Both the binary (H2SO4–H2O) system and the
ternary system involving ammonia (H2SO4–H2O–NH3) may be
important in the free troposphere. An essential step in the nucleation of
aerosol particles from gas-phase precursors is the formation of a dimer, so
an understanding of the thermodynamics of dimer formation over a wide range
of atmospheric conditions is essential to describe NPF. We have used the
CLOUD chamber to conduct nucleation experiments for these systems at
temperatures from 208 to 248 K. Neutral monomer and dimer concentrations of
sulfuric acid were measured using a chemical ionization mass spectrometer
(CIMS). From these measurements, dimer evaporation rates in the binary system
were derived for temperatures of 208 and 223 K. We compare these results to
literature data from a previous study that was conducted at higher
temperatures but is in good agreement with the present study. For the
ternary system the formation of H2SO4·NH3 is very
likely an essential step in the formation of sulfuric acid dimers, which
were measured at 210, 223, and 248 K. We estimate the thermodynamic
properties (dH and dS) of the H2SO4·NH3 cluster
using a simple heuristic model and the measured data. Furthermore, we report
the first measurements of large neutral sulfuric acid clusters containing as
many as 10 sulfuric acid molecules for the binary system using chemical
ionization–atmospheric pressure interface time-of-flight (CI-APi-TOF) mass
spectrometry. |
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