Oxygenated Interface on Biomass Burn Tar Balls Determined by Single Particle Scanning Transmission X-ray Microscopy

Alexei V Tivanski; Rebecca J Hopkins; Tolek Tyliszczak; Mary K Gilles

doi:10.1021/jp070155u

Back

Oxygenated Interface on Biomass Burn Tar Balls Determined by Single Particle Scanning Transmission X-ray Microscopy

Journal article

Open access

Oxygenated Interface on Biomass Burn Tar Balls Determined by Single Particle Scanning Transmission X-ray Microscopy

Alexei V Tivanski, Rebecca J Hopkins, Tolek Tyliszczak and Mary K Gilles

The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory, Vol.111(25), pp.5448-5458

06/01/2007

DOI: 10.1021/jp070155u

PMID: 17542565

Files and links (1)

url

https://doi.org/10.1021/jp070155uView

Published (Version of record) Open Access

Abstract

Carbonaceous particles originating from biomass burning can account for a large fraction of organic aerosols in a local environment. Presently, their composition, physical and chemical properties, as well as their environmental effects are largely unknown. Tar balls, a distinct type of highly spherical carbonaceous biomass burn particles, have been observed in a number of field campaigns. The Yosemite Aerosol Characterization Study that took place in summer 2002 occurred during an active fire season in the western United States; tar balls collected during this field campaign are described in this article. Scanning transmission X-ray microscopy and riear-edge X-ray absorption fine structure spectroscopy are used to determine the shape, structure, and size-dependent chemical composition of ∼150 individual spherical particles ranging in size from 0.15 to 1.2 μm. The elemental composition of tar balls is ∼55% atomic carbon and ∼45% atomic oxygen. Oxygen is present primarily as carboxylic carbonyls and oxygen-substituted alkyl (O-alkyl-C) functional groups, followed by moderate amounts of ketonic carbonyls. The observed chemical composition, density, and carbon functional groups are distinctly different from soot or black carbon and more closely resemble high molecular weight polymeric humic-like substances, which could account for their reported optical properties. A detailed examination of the carboxylic carbonyl and O-alkyl-C functional groups as a function of particle size reveals a thin oxygenated interface layer. The high oxygen content, as well as the presence of water-soluble carboxylic carbonyl groups, could account for the reported hygroscopic properties of tar balls. The presence of the oxygenated layer is attributed to atmospheric processing of biomass burn particles. © 2007 American Chemical Society.

Details

Title: Subtitle: Oxygenated Interface on Biomass Burn Tar Balls Determined by Single Particle Scanning Transmission X-ray Microscopy
Creators: Alexei V Tivanski - Chemical Science Division and Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720
Rebecca J Hopkins - Chemical Science Division and Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720
Tolek Tyliszczak - Chemical Science Division and Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720
Mary K Gilles - Chemical Science Division and Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720
Resource Type: Journal article
Publication Details: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory, Vol.111(25), pp.5448-5458
DOI: 10.1021/jp070155u
PMID: 17542565
NLM abbreviation: J Phys Chem A
ISSN: 1089-5639
eISSN: 1520-5215
Language: English
Date published: 06/01/2007
Academic Unit: Chemistry
Record Identifier: 9984216564602771

Metrics

13 Record Views

86 Times Cited - Web of Science