Phase partitioning of aerosol particles during crystallization

Ge, Zhaozhu; Wexler, Anthony S.; Johnston, Murray V.

doi:10.1016/b978-008042030-1/50110-4

Cited by 2 publications

(2 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is supported by single-particle analyses at rural and remote sites. For example, the accumulation of nitrate on the surface of sea salt particles and of sulfate on various types of particles, salt and SOA, has been observed ( − ).…”

Section: Contributions To the Gas-particle Partitioningmentioning

confidence: 99%

Adsorptive and Absorptive Contributions to the Gas-Particle Partitioning of Polycyclic Aromatic Hydrocarbons: State of Knowledge and Recommended Parametrization for Modeling

Lohmann

Lammel

2004

Environ. Sci. Technol.

303

228

View full text Add to dashboard Cite

Four contrasting descriptions of the gas-particle partitioning of SOCs are currently used: the Junge-Pankow adsorption model, the empirical Finizio organic matter (OM) absorption relationship, the Harner-Bidleman OM absorption model, and a dual black carbon (BC) adsorption and OM absorption model. Use of these four descriptions in a box model resulted in very different global fates, particularly for PAHs such as chrysene and benzo[a]pyrene. By reviewing published gas-particle distributions of PAHs, we found evidence for both absorptive and adsorptive contributions. Based on results from laboratory and controlled field studies we suggest that on average, octanol-air partitioning (Koa) is a good approximation for the OM absorption of PAHs. However, higher concentrations in particles than could be explained by OM absorption were found in selected gas-particle partitioning field studies, which were corrected for gaseous adsorption to the filter. We argue that adsorption onto BC is responsible for most of the additional sorption. Apparent adsorption coefficients to BC, K(BC-air), were derived from field studies and showed good agreement with those predicted by adsorption onto diesel soot. For atmospheric long-range transport models we suggestthe use of a dual OM absorption and BC adsorption model, with BC properties being approximated by diesel soot: Kp = 10(-12) (f(om) 1/rho(oct) Koa + fBC/rho(BC) K(soot-air) a(atm-BC)/a(soot)). We hypothesize that kinetic constraints related to shell-like particle structures might lead to deviations from sorption equilibrium and higher particle-borne fractions of PAHs in particular at remote sites.

show abstract

Section: Contributions To the Gas-particle Partitioningmentioning

confidence: 99%

Adsorptive and Absorptive Contributions to the Gas-Particle Partitioning of Polycyclic Aromatic Hydrocarbons: State of Knowledge and Recommended Parametrization for Modeling

Lohmann

Lammel

2004

Environ. Sci. Technol.

303

228

View full text Add to dashboard Cite

show abstract

“…In most laboratory studies of aerosol chemistry, standard techniques have been used to analyze collected aerosol samples (Robbins and Cadle, 1958;Daumer, Neissner, and Klockow, 1992;Forstner, 1997) or bulk materials employed as aerosol surrogates (Vogt and Finlayson-Pitts, 1994;Smith and Chughtai, 1996), or they have Aerosol Science and Technology 28:l January 1998 been used to measure gas uptake by droplets (Worsnop et al, 1989;Fried et al, 1994). Only a few techniques have the capability of differentiating between surface and bulk properties of suspended particles in real time, including photoelectric charging (Burtscher and Schmidt-Ott, 1986), spectroscopic or gravimetric analysis of single, levitated particles (Davis, 1996), and laser desorption/single-particle mass spectrometry, (Ge, Wexler, and Johnston, 1996;Middlebrook, Thomson, and Murphy, 1997).…”

Section: Introductionmentioning

confidence: 99%

Secondary Electron Yield Measurements as a Means for Probing Organic Films on Aerosol Particles

Ziemann¹,

McMurry²

1998

Aerosol Science and Technology

View full text Add to dashboard Cite

ABSTRACT. Secondary electron yields of salt particles (KC1 and NaCI) coated with organic films (dioctyl sebacate and octacosane) were measured by impacting aerosol particles with monoenergetic electrons (10-600 eV) inside a particle beam apparatus. The results demonstrate that secondary electron yield measurements can be used to obtain information on the structure of organic films on aerosol particles. The technique relies upon the large differences in the yields of organic compounds and certain salts in order to obtain a measurable contrast in the yields of clean and coated particles. Secondary electron yields measured as a function of primary electron energy and film coverage show that the probe depth of electrons increases with energy and is -10-20 nm for the range of energies investigated. The technique is sufficiently sensitive that submonolayer films can be detected. Measurements made within the rnonolayer regime suggest that vapor-deposited dioctyl sebacate (DOS) forms uniformly thick films, and that the thickness of one rnonolayer is -0.7 nm. Similar measurements made for octacosane suggest that multilayer films are formed by this compound, even below the nominal monolayer point. The utility of the technique for studies of aerosol chemistry is demonstrated in an investigation of the behavior of octacosane-coated NaCl particles subjected to a hydration-dehydration cycle.

show abstract

Phase partitioning of aerosol particles during crystallization

Cited by 2 publications

References 3 publications

Adsorptive and Absorptive Contributions to the Gas-Particle Partitioning of Polycyclic Aromatic Hydrocarbons: State of Knowledge and Recommended Parametrization for Modeling

Adsorptive and Absorptive Contributions to the Gas-Particle Partitioning of Polycyclic Aromatic Hydrocarbons: State of Knowledge and Recommended Parametrization for Modeling

Secondary Electron Yield Measurements as a Means for Probing Organic Films on Aerosol Particles

Contact Info

Product

Resources

About