Thermodynamics of the formation of sulfuric acid dimers in the binary (H2SO4-H2O) and ternary (H2SO4-H2O-NH3) system

Autor(en)

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, Gerhard Steiner, A. Tome, G. Tsagkogeorgas, Paul Wagner, D. Wimmer, U. Baltensperger, Markku Kulmala, D. R. Worsnop, J. Curtius

Abstrakt

Sulfuric acid is an important gas influencing atmospheric new particle formation (NPF). Both the binary (H

₂SO

₄-H

₂O) system and the ternary system involving ammonia (H

₂SO

₄-H

₂O-NH

₃) 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 H

₂SO

₄·NH

₃ 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 H

₂SO

₄·NH

₃ 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.

Organisation(en)

Aerosolphysik und Umweltphysik

Externe Organisation(en)

Johann Wolfgang Goethe-Universität Frankfurt am Main, Paul Scherrer Institute, Eidgenössische Technische Hochschule Zürich, European Organization for Nuclear Research (CERN), University of Helsinki, Universidade de Lisboa, Carnegie Mellon University, University of Leeds, California Institute of Technology (Caltech), Russian Academy of Sciences, Leibniz-Institut für Troposphärenforschung, Aerodyne Res Inc, Leopold-Franzens-Universität Innsbruck

Journal

Atmospheric Chemistry and Physics

Band

15

Seiten

10701-10721

Anzahl der Seiten

21

ISSN

1680-7316

DOI

https://doi.org/10.5194/acp-15-10701-2015

Publikationsdatum

05-2015

Peer-reviewed

Ja

ÖFOS 2012

103037 Umweltphysik, 103039 Aerosolphysik

Schlagwörter

ASJC Scopus Sachgebiete

Atmospheric Science

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/6dbd3701-3808-4068-b903-a1d6ebc70708