Experimental evidence of reduced sticking of nanoparticles on a metal grid

Coen van Gulijk, Evert Bal, Andreas Schmidt-Ott

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

Filtering of NaCl, CaCl2, (NH4)2SO4 and NiSO4 aerosol particles 7-20 nm in diameter by a stainless steel grid was studied in order to find out if there is perfect sticking or partial rebound. Our experiment used particles from a spray-drying process, the majority of which were electrically neutral. Penetration through the grid was measured by comparing the concentration downstream of the grid with the upstream concentration under otherwise identical conditions. Size selection was done with a scanning mobility particle sizer (SMPS). Filter penetration P as function of the particle diameter dp was expressed by - ln (P (dp)) = C dp- x. The values of x determined were smaller than the theoretical value of 1.29, indicating enhanced penetration of small particles and deviation from the classical filtration model. Because of possible systematic errors in the size selection, we focus on the differences of x from material to material, which indicate different sticking probabilities. We apply a statistical test, which yields a 90% confidence level for the result. There is a sticking probability of <100% at least for NaCl particles and even more so for NiSO4. This result is in contrast to former findings using metal and/or charged particles, and we speculate that the discrepancy is due to the smaller Hamaker constant of salts and that particle charge is important for the sticking probability.

LanguageEnglish
Pages362-369
Number of pages8
JournalJournal of Aerosol Science
Volume40
Issue number4
Early online date30 Dec 2008
DOIs
Publication statusPublished - Apr 2009
Externally publishedYes

Fingerprint

Metals
Nanoparticles
metal
Spray drying
Statistical tests
Systematic errors
Stainless Steel
size selection
Charged particles
penetration
Aerosols
Particles (particulate matter)
Stainless steel
Salts
Scanning
nanoparticle
particle
spray
Experiments
steel

Cite this

van Gulijk, Coen ; Bal, Evert ; Schmidt-Ott, Andreas. / Experimental evidence of reduced sticking of nanoparticles on a metal grid. In: Journal of Aerosol Science. 2009 ; Vol. 40, No. 4. pp. 362-369.
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Experimental evidence of reduced sticking of nanoparticles on a metal grid. / van Gulijk, Coen; Bal, Evert; Schmidt-Ott, Andreas.

In: Journal of Aerosol Science, Vol. 40, No. 4, 04.2009, p. 362-369.

Research output: Contribution to journalArticle

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