Identification of Polymers as Major Components of Atmospheric Organic Aerosols

• Published in: Science (American Association for the Advancement of Science) Vol. 303; no. 5664; pp. 1659 - 1662
• Main Authors: Kalberer, M., Paulsen, D., Sax, M., Steinbacher, M., Dommen, J., Prevot, A. S. H., Fisseha, R., Weingartner, E., Frankevich, V., Zenobi, R., Baltensperger, U.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 12-03-2004; The American Association for the Advancement of Science
• Subjects: Acetals; Aerosols; Applied sciences; Atmospheric aerosols; Atmospheric chemistry; Atmospheric pollution; Average linear density; Chemical properties; Earth, ocean, space; Exact sciences and technology; External geophysics; Irradiation; Meteorology; Monomers; Organic chemicals; Organic Chemistry; Oxidation; Particle mass; Particles and aerosols; Photooxidation; Pollutants physicochemistry study: properties, effects, reactions, transport and distribution; Pollution; Polymerization; Polymers; Urban Areas; Switzerland; Reaction product; Pollutant formation; Troposphere; Polymerization; Secondary pollutant; Volatile organic compound; Photochemical reaction; Aldehyde; Experimental study; Ketone; Precursor; Atmospheric chemistry; Aerosols; Reaction mechanism; Air pollution; Oxidation
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1092185

Results from photooxidation of aromatic compounds in a reaction chamber show that a substantial fraction of the organic aerosol mass is composed of polymers. This polymerization results from reactions of carbonyls and their hydrates. After aging for more than 20 hours, about 50% of the particle mass consists of polymers with a molecular mass up to 1000 daltons. This results in a lower volatility of this secondary organic aerosol and a higher aerosol yield than a model using vapor pressures of individual organic species would predict.