Characterization of surface functional groups present on laboratory-generated and ambient aerosol particles by means of heterogeneous titration reactions

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Version: Author's accepted manuscript
Serval ID
serval:BIB_B477DBDA9F10
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Characterization of surface functional groups present on laboratory-generated and ambient aerosol particles by means of heterogeneous titration reactions
Journal
Journal of Aerosol Science
Author(s)
Setyan Ari, Sauvain Jean-Jacques, Riediker Michael, Guillemin Michel, Rossi Michel J.
ISSN
0021-8502
Publication state
Published
Issued date
2009
Peer-reviewed
Oui
Volume
40
Number
6
Pages
534-548
Language
english
Notes
SAPHIRID:79161
Abstract
A Knudsen flow reactor has been used to quantify surface functional groups on aerosols collected in the field. This technique is based on a heterogeneous titration reaction between a probe gas and a specific functional group on the particle surface. In the first part of this work, the reactivity of different probe gases on laboratory-generated aerosols (limonene SOA, Pb(NO3)2, Cd(NO3)2) and diesel reference soot (SRM 2975) has been studied. Five probe gases have been selected for the quantitative determination of important functional groups: N(CH3)3 (for the titration of acidic sites), NH2OH (for carbonyl functions), CF3COOH and HCl (for basic sites of different strength), and O3 (for oxidizable groups). The second part describes a field campaign that has been undertaken in several bus depots in Switzerland, where ambient fine and ultrafine particles were collected on suitable filters and quantitatively investigated using the Knudsen flow reactor. Results point to important differences in the surface reactivity of ambient particles, depending on the sampling site and season. The particle surface appears to be multi-functional, with the simultaneous presence of antagonistic functional groups which do not undergo internal chemical reactions, such as acid-base neutralization. Results also indicate that the surface of ambient particles was characterized by a high density of carbonyl functions (reactivity towards NH2OH probe in the range 0.26-6 formal molecular monolayers) and a low density of acidic sites (reactivity towards N(CH3)3 probe in the range 0.01-0.20 formal molecular monolayer). Kinetic parameters point to fast redox reactions (uptake coefficient ?0>10-3 for O3 probe) and slow acid-base reactions (?0<10-4 for N(CH3)3 probe) on the particle surface. [Authors]
Keywords
Vehicle Emissions , Aerosols , Particulate Matter , Oxidative Stress , Reactive Oxygen Species , Biological Markers , Surface Properties , Occupational Exposure
Web of science
Open Access
Yes
Create date
19/01/2010 17:30
Last modification date
20/08/2019 15:22
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