Oxidation and replacement of oleic acid at the air/water interface to understand fat-coated aerosols

COLL 13

Laura F. Voss, lvoss@chemistry.ohio-state.edu, Kandice L. Harper, kharper@chemistry.ohio-state.edu, Mohamad F. Bazerbashi, Christopher M. Hadad, hadad.1@osu.edu, and Heather C. Allen, allen@chemistry.ohio-state.edu. Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210
Field studies of marine and continental aerosols find that fatty acid films form on aqueous tropospheric aerosols. Oxidation of the acyl chains is thought to be key to aerosol growth. Using vibrational sum frequency generation spectroscopy and reflection absorption infrared spectroscopy, we present a molecular-level investigation of the interfacial structure of fatty acid monolayers at the air-water interface and explore reactions with atmospheric oxidants by these model systems. Results include reaction of oleic acid with atmospheric oxidants and subsequent replacement of the products at the interface by less soluble species from the aqueous subphase.