Modification in light absorption cross section of laboratory-generated black carbon-brown carbon particles upon surface reaction and hydration
Abstract : Recent reports indicate that the absorption enhancement of black carbon (BC) and brown carbon (BrC)
particles is determined by the evolution of morphology and mixing state during the atmospheric processing.
In this study, laboratory-generated BC-BrC mixture particles (BC-BrC) were exposed to sulfuric
acid, ammonia/triethylamine, and water vapor sequentially to investigate the alteration in light absorption,
morphology and mixing state during simulated atmospheric processing. Condensation of sulfuric
acid and exposure to ammonia or triethylamine at 5% relative humidity decreased light absorption
cross section of BC-BrC by 13%e26%, but subsequent hydration at 85% relative humidity led to an increase
by 5%e20%. Our results show that surface reactions and hydration can significantly alter the light absorption
cross section of BC-BrC. Our observation suggests that the restructuring of BC-BrC induced by
neutralization reactions on the BC-BrC surface was responsible for the reduction in light absorption cross
section at low relative humidity. On the other hand, the formation of an aqueous coating through water
uptake by the hydrophilic inorganic coating at high relative humidity caused an absorption
enhancement.
Cited literature [25 references]
https://hal-insu.archives-ouvertes.fr/insu-01174615
Contributor : Nathalie Pothier <>
Submitted on : Wednesday, September 2, 2015 - 3:43:13 PM
Last modification on : Wednesday, March 20, 2019 - 1:20:20 AM
Document(s) archivé(s) le : Wednesday, April 26, 2017 - 2:40:54 PM
Contributor : Nathalie Pothier <>
Submitted on : Wednesday, September 2, 2015 - 3:43:13 PM
Last modification on : Wednesday, March 20, 2019 - 1:20:20 AM
Document(s) archivé(s) le : Wednesday, April 26, 2017 - 2:40:54 PM
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BC-BrC 20150616.pdf
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