Ozonolysis of fatty acid monolayers at the air–water interface: organic films may persist at the surface of atmospheric aerosols

• Published in: Atmospheric chemistry and physics 2021-02, Vol.21 (2), p.1325-1340
• Main Authors: Woden, Benjamin, Skoda, Maximilian W. A, Milsom, Adam, Gubb, Curtis, Maestro, Armando, Tellam, James, Pfrang, Christian
• Format: Article
• Language: English
• Subjects: Aerosols; Air; Air temperature; Air-water interface; Atmospheric aerosols; Atmospheric conditions; Atmospheric models; Climate models; Cloud formation; Clouds; Coefficients; Dielectric films; Fatty acids; Life cycle; Life cycles; Low temperature; Monolayers; Monomolecular films; Monounsaturated fatty acids; Oleic acid; Oxidation; Ozonolysis; Physical properties; Reaction products; Room temperature; Surface films; Surface tension; Temperature; Temperature effects; Thin films
• ISSN: 1680-7324; 1680-7316; 1680-7324
• DOI: 10.5194/acp-21-1325-2021

Ozonolysis of fatty acid monolayers was studied to understand the fate of organic-coated aerosols under realistic atmospheric conditions. Specifically, we investigated the effects of temperature and salinity on the degradation of oleic acid at the air-water interface and the persistence of the aged surfactant film at the surface. The presence of a residual film is of atmospheric importance, as surface monolayers affect the physical properties of the droplets and because of the role they play in cloud formation. This occurs via several effects, most notably via surface tension reduction. The interplay between atmospheric aerosol loading and the formation, nature, and persistence of clouds is a key uncertainty in climate modelling.