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Observation of hydration of single, modified carbon aerosols
Author(s) -
Wyslouzil B. E.,
Carleton K. L.,
Sonnenfroh D. M.,
Rawlins W. T.,
Arnold S.
Publication year - 1994
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/94gl01588
Subject(s) - aerosol , relative humidity , mass fraction , sulfuric acid , nucleation , carbon fibers , fraction (chemistry) , adsorption , mass concentration (chemistry) , materials science , chemistry , analytical chemistry (journal) , environmental chemistry , inorganic chemistry , meteorology , chromatography , organic chemistry , composite number , composite material , physics
We have compared the hydration behavior of single carbon particles that have been treated by exposure to gaseous H 2 SO 4 with that of untreated particles. Untreated carbon particles did not hydrate as the relative humidity varied from 0 to 80% at 23°C. In contrast, treated particles hydrated under subsaturation conditions ; mass increases of up to 30% were observed. The mass increase is consistent with sulfuric acid equilibration with the ambient relative humidity in the presence of inert carbon. For the samples studied, the average amount of adsorbed acid was 14% ± 6% by weight, which corresponds to a surface coverage of ∼0.1 monolayer. The mass fraction of surface‐adsorbed acid is comparable to the soluble mass fraction observed by Whitefield et al. (1993) in jet aircraft engine aerosols. Estimates indicate this mass fraction corresponds to 0.1% of the available SO 2 exiting an aircraft engine ending up as H 2 SO 4 on the carbon aerosol. If this heterogeneous process occurs early enough in the exhaust plume, it may compete with homogeneous nucleation as a mechanism for producing sulfuric acid rich aerosols.