Preprints
https://doi.org/10.5194/acpd-5-3847-2005
https://doi.org/10.5194/acpd-5-3847-2005
10 Jun 2005
 | 10 Jun 2005
Status: this preprint was under review for the journal ACP but the revision was not accepted.

Coagulation of combustion generated nanoparticles and their measurement behind vehicle engines: can they play a role as atmospheric pollutants?

H.-H. Grotheer, T. Gonzalez Baquet, M. Thierley, H. Pokorny, and M. Aigner

Abstract. Based on photoionisation mass spectrometry two types of experiments were carried out. (i) In a fast flow reactor coupled to a low pressure flame as a particle source, rate coefficients for the coagulation of primary nanoparticles were measured through variation of the reactor residence time. The results are kc (350K) = 3.5x10-10cm3/s and kc (573K) = 1.1x10-9cm3/s, i.e. very high rate coefficients. It was also shown that coagulated nanoparticles can have masses beyond 50ku, corresponding to equivalent diameters between 4 to 5nm. These particles are easily fragmented during photoionisation. (ii) Using a second and mobile photoionisation mass spectrometer equipped with a fast flow inlet system, measurements were carried out behind three different vehicle engines, a two-stroke scooter engine, a four-stroke motorbike engine and a DI (direct injection) gasoline research engine. In all cases ion signals around 1000u were found that are clearly dependent on engine conditions. In the case of the DI engine, they correlate with the smoke number. These signals cannot be explained by PAHs due to their low volatility at the respective masses. Major contributions of soot or droplet fragmentation were ruled out through additional experiments using a heated inlet line and a filter. Consequently, these signals are interpreted as fragments of coagulated nanoparticles.

H.-H. Grotheer, T. Gonzalez Baquet, M. Thierley, H. Pokorny, and M. Aigner
 
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
 
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
H.-H. Grotheer, T. Gonzalez Baquet, M. Thierley, H. Pokorny, and M. Aigner
H.-H. Grotheer, T. Gonzalez Baquet, M. Thierley, H. Pokorny, and M. Aigner

Viewed

Total article views: 1,966 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
1,125 734 107 1,966 103 106
  • HTML: 1,125
  • PDF: 734
  • XML: 107
  • Total: 1,966
  • BibTeX: 103
  • EndNote: 106
Views and downloads (calculated since 01 Feb 2013)
Cumulative views and downloads (calculated since 01 Feb 2013)

Saved

Latest update: 28 Mar 2024
Download
Altmetrics