AGS-PRF: Characterizing the Physicochemical Properties of Primary and Secondary Ultrafine Particles from Brake Emissions

In this Postdoctoral Research Fellowship project, the PI will join a team of researchers at the University of California Irvine in order to study the properties of ultrafine aerosol emissions from brake wear via laboratory experiments and a small-scale filter-based field campaign. Aerosol emissions from brake wear has recently been identified as a major contributor to non-exhaust related emissions from the transportation sector and with the ongoing shift to electric vehicles, the relative important of non-exhaust emissions are of growing importance. The PI will additionally collaborate with a local nonprofit organization working towards improved air quality and cleaner air as well as collaborate with filmmakers in order to produce bilingual (English and Spanish) science education videos related to this research. The work includes three research questions: (1) What are the physiochemical properties of ultrafine particles formed from break wear? (2) How do these properties change after undergoing secondary atmospheric processing including oxidation and photodegradation? (3) Are ultrafine particles from brake wear present in ambient samples from Santa Ana, California? There are three main research approaches: (1) laboratory experiments on the formation of ultrafine particles from brake emissions; (2) the use of an oxidation flow reactor to characterize the formation of secondary species; and (3) the collection of ultrafine particles generated from brake wear emissions on filters within Santa Ana, California, and the study of their chemistry via exposure to ultraviolet radiation. Multiple instruments will be used during this project including various mass spectrometers as well as a transmission electron microscope. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.