Sign up & Download
Sign in

Evolution of particle composition in CLOUD nucleation experiments

by H. Keskinen, a. Virtanen, J. Joutsensaari, G. Tsagkogeorgas, J. Duplissy, S. Schobesberger, M. Gysel, F. Riccobono, J. G. Slowik, F. Bianchi, T. Yli-Juuti, K. Lehtipalo, L. Rondo, M. Breitenlechner, a. Kupc, J. Almeida, a. Amorim, E. M. Dunne, a. J. Downard, S. Ehrhart, a. Franchin, M. K. Kajos, J. Kirkby, a. Kürten, T. Nieminen, V. Makhmutov, S. Mathot, P. Miettinen, a. Onnela, T. Petäjä, a. Praplan, F. D. Santos, S. Schallhart, M. Sipilä, Y. Stozhkov, a. Tomé, P. Vaattovaara, D. Wimmer, a. Prevot, J. Dommen, N. M. Donahue, R. C. Flagan, E. Weingartner, Y. Viisanen, I. Riipinen, a. Hansel, J. Curtius, M. Kulmala, D. R. Worsnop, U. Baltensperger, H. Wex, F. Stratmann, a. Laaksonen show all authors
Atmospheric Chemistry and Physics ()


Sulphuric acid, ammonia, amines, and oxidised organics play a crucial role in nanoparticle formation in the atmosphere. In this study, we investigate the composition of nucleated nanoparticles formed from these compounds in the CLOUD (Cosmics Leaving Outdoor Droplets) chamber experiments at CERN (Centre europeen pour la recherche nucleaire). The investigation was carried out via analysis of the particle hygroscopicity, ethanol affinity, oxidation state, and ion composition. Hygroscopicity was studied by a hygroscopic tandem differential mobility analyser and a cloud condensation nuclei counter, ethanol affinity by an organic differential mobility analyser and particle oxidation level by a high-resolution time-of-flight aerosol mass spectrometer. The ion composition was studied by an atmospheric pressure interface time-of-flight mass spectrometer. The volume fraction of the organics in the particles during their growth from sizes of a few nanometers to tens of nanometers was derived from measured hygroscopicity assuming the Zdanovskii-Stokes-Robinson relationship, and compared to values gained from the spectrometers. The ZSR-relationship was also applied to obtain the measured ethanol affinities during the particle growth, which were used to derive the volume fractions of sulphuric acid and the other inorganics (e. g. ammonium salts). In the presence of sulphuric acid and ammonia, particles with a mobility diameter of 150 nm were chemically neutralised to ammonium sulphate. In the presence of oxidation products of pinanediol, the organic volume fraction of freshly nucleated particles increased from 0.4 to similar to 0.9, with an increase in diameter from 2 to 63 nm. Conversely, the sulphuric acid volume fraction decreased from 0.6 to 0.1 when the particle diameter increased from 2 to 50 nm. The results provide information on the composition of nucleated aerosol particles during their growth in the presence of various combinations of sulphuric acid, ammonia, dimethylamine and organic oxidation products.

Cite this document (BETA)

Readership Statistics

24 Readers on Mendeley
by Discipline
by Academic Status
29% Ph.D. Student
21% Post Doc
17% Student (Master)
by Country
4% Germany
4% United Kingdom
4% United States

Sign up today - FREE

Mendeley saves you time finding and organizing research. Learn more

  • All your research in one place
  • Add and import papers easily
  • Access it anywhere, anytime

Start using Mendeley in seconds!

Sign up & Download

Already have an account? Sign in