Electron tomography of nanoparticle clusters: Implications for atmospheric lifetimes and radiative forcing of soot

Poppel, Laura H. van; Friedrich, Heiner; Spinsby, J.; Chung, S. H.; Seinfeld, John H.; Buseck, Peter R.

doi:10.1029/2005gl024461

Cited by 99 publications

(90 citation statements)

References 29 publications

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“…2. Consistent with other authors (Adachi et al, 2007;van Poppel et al, 2005;Kis et al, 2006), primary particles are found with a size of about 30-40 nm aggregated in chains. Inspection by eye does not reveal changes in aggregation of the particles, which is supported by the evaluation of the fractal dimension revealing 1.84 (±0.03) for fresh and 1.85 (±0.05) for processed particles, respectively.…”

Section: Particle Morphology and Size Distributionsupporting

confidence: 81%

Aging induced changes on NEXAFS fingerprints in individual combustion particles

et al. 2011

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Abstract. Soot particles can significantly influence the Earth's climate by absorbing and scattering solar radiation as well as by acting as cloud condensation nuclei. However, despite their environmental (as well as economic and political) importance, the way these properties are affected by atmospheric processing of the combustion exhaust gases is still a subject of discussion. In this work, individual soot particles emitted from two different vehicles, a EURO 2 transporter, a EURO 3 passenger car, and a wood stove were investigated on a single-particle basis. The emitted exhaust, including the particulate and the gas phase, was processed in a smog chamber with artificial solar radiation. Single particle specimens of both unprocessed and aged soot were characterized using near edge X-ray absorption fine structure spectroscopy (NEXAFS) and scanning electron microscopy. Comparison of NEXAFS spectra from the unprocessed particles and those resulting from exhaust photooxidation in the chamber revealed changes in the carbon functional group content. For the wood stove emissions, these changes were minor, related to the relatively mild oxidation conditions. For the EURO 2 transporter emissions, the most apparent change was that of carboxylic carbon from oxidized organic compounds condensing on the primary soot particles. For the EURO 3 car emissions oxidation of primary soot particles upon photochemical aging has likely contributed as well. Overall, Correspondence to: M. Ammann (markus.ammann@psi.ch) the changes in the NEXAFS fingerprints were in qualitative agreement with data from an aerosol mass spectrometer. Furthermore, by taking full advantage of our in situ microreactor concept, we show that the soot particles from all three combustion sources changed their ability to take up water under humid conditions upon photochemical aging of the exhaust. Due to the selectivity and sensitivity of the NEXAFS technique for the water mass, also small amounts of water taken up into the internal voids of agglomerated particles could be detected. Because such small amounts of water uptake do not lead to measurable changes in particle diameter, it may remain beyond the limits of volume growth measurements, especially for larger agglomerated particles.

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Section: Particle Morphology and Size Distributionsupporting

confidence: 81%

Aging induced changes on NEXAFS fingerprints in individual combustion particles

et al. 2011

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“…13a and c). Most of the biological particles were likely spores or conidia of fungi (Wittmaack et al, 2005), but the detailed classification of these particles was beyond the scope of this work. There were also several angular C-rich particles without clearly characteristic morphology of biological particles ( Fig.…”

Section: Biological Particles and C-rich Fragmentsmentioning

confidence: 99%

“…In Finland, anthropogenic emissions of particles and their precursor gases are low (EMEP, 2001(EMEP, , 2002, and most of the PM 2.5 mass originates from long-range transport (Pakkanen et al, 2001;Vallius et al, 2003;Karppinen et al, 2004). In general, PM 2.5 concentrations are also low, the annual mean PM 2.5 concentration being only 5.8 µg m −3 at the rural station of Hyytiälä in southern Finland (Laakso et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

Changes in background aerosol composition in Finland during polluted and clean periods studied by TEM/EDX individual particle analysis

Niemi

Saarikoski

Tervahattu³

et al. 2006

Atmos. Chem. Phys.

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Abstract.Aerosol samples were collected at a rural background site in southern Finland in May 2004 during pollution episode (PM 1 ∼16 µg m −3 , backward air mass trajectories from south-east), intermediate period (PM 1 ∼5 µg m −3 , backtrajectories from north-east) and clean period (PM 1 ∼2 µg m −3 , backtrajectories from northwest/north). The elemental composition, morphology and mixing state of individual aerosol particles in three size fractions were studied using transmission electron microscopy (TEM) coupled with energy dispersive X-ray (EDX) microanalyses. The TEM/EDX results were complemented with the size-segregated bulk chemical measurements of selected ions and organic and elemental carbon. Many of the particles in PM 0.2−1 and PM 1−3.3 size fractions were strongly internally mixed with S, C and/or N. The major particle types in PM 0.2−1 samples were 1) soot and 2) (ammonium)sulphates and their mixtures with variable amounts of C, K, soot and/or other inclusions. Number proportions of those two particle groups in PM 0.2−1 samples were 0-12% and 83-97%, respectively. During the pollution episode, the proportion of Ca-rich particles was very high (26-48%) in the PM 1−3.3 and PM 3.3−11 samples, while the PM 0.2−1 and PM 1−3.3 samples contained elevated proportions of silicates (22-33%), metal oxides/hydroxides (1-9%) and tar balls (1-4%). These aerosols originated mainly from polluted areas of Eastern Europe, and some open biomass burning smoke was also brought by long-range transport. During the clean period, when air masses arrived from the Arctic Ocean, PM 1−3.3 samples contained mainly sea salt particles (67-89%) with a variable rate of Cl substitution (mainly by NO porous (sponge-like) Na-rich particles (35%) with abundant S, K and O. They might originate from the burning of wood pulp wastes of paper industry. The proportion of biological particles and C-rich fragments (probably also biological origin) were highest in the PM 3.3−11 samples (0-81% and 0-22%, respectively). The origin of different particle types and the effect of aging processes on particle composition and their hygroscopic and optical properties are discussed.

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“…Visual scanning is rapid and can be used to select a relatively small number of particles that appear to be representative and, if appropriate, can then be subjected to detailed studies using electron tomography to determine their 3D shapes (van Poppel et al 2005;Adachi et al 2007). Morphology and mixing state strongly influence the scattering cross-sections of ns-soot.…”

Section: Associated Materials Coating Embeddingmentioning

confidence: 99%

Ns-Soot: A Material-Based Term for Strongly Light-Absorbing Carbonaceous Particles

Buseck

Adachi

Gelencsér

et al. 2014

Aerosol Science and Technology

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105

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The climate-change and environmental literature, including that on aerosols, is replete with mention of black carbon (BC) and soot. The terms are used interchangeably in much of the literature, although BC and soot commonly have operational and source-based definitions, respectively, and reliable reference samples and aerosol standards do not exist for either one. The uncertainty about their exact chemical nature and properties can be decreased by materials-based measurement techniques and terminology. Here, we discuss ambiguities in common uses of BC and soot and propose the term ns-soot, where "ns" refers to carbon nanospheres, for a characteristic constituent of BC and soot. Based on its composition, morphology, and structure, we define ns-soot as particles that consist of nanospheres, typically with diameters <100 nm, that possess distinct structures of concentrically wrapped, graphene-like layers of carbon and with grape-like (aciniform) morphologies. We additionally propose that, because of their importance for climate modeling and health issues, distinctions are made among bare, coated, and embedded ns-soot particles.

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Electron tomography of nanoparticle clusters: Implications for atmospheric lifetimes and radiative forcing of soot

Cited by 99 publications

References 29 publications

Aging induced changes on NEXAFS fingerprints in individual combustion particles

Aging induced changes on NEXAFS fingerprints in individual combustion particles

Changes in background aerosol composition in Finland during polluted and clean periods studied by TEM/EDX individual particle analysis

Ns-Soot: A Material-Based Term for Strongly Light-Absorbing Carbonaceous Particles

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