CAREER: Influence of Microplastics on Aerosol Processes

With support from the Environmental Chemical Sciences (ECS) program in the Chemistry Section, Professor Alison Bain at Oregon State University is investigating the impact of atmospheric micro- and nanoplastics on the physical properties of mixed-phase aerosol droplets. Field studies now routinely find micro- and nanoplastics in atmospheric aerosol samples. However, the impacts of these plastics on aerosol-phase properties and processes are not well understood. Professor Bain and her students will conduct macroscopic and aerosol droplet-scale experiments utilizing plastics of different chemical structures and morphologies to systematically study the impacts of the timescale of environmental aging on the surface morphology and chemistry of micro- and nanoplastics; the uptake of water and other chemical species; and the mixing of micro- and nanoplastics with existing aerosols. Their studies could establish a fundamental understanding of the impact of micro- and nanoplastics on aerosol physical properties, which could significantly contribute to the scientific understanding of the interactions between atmospheric plastics and other aerosols. The educational efforts of this project include training undergraduate students to efficiently handle large datasets common in analytical and environmental chemistry, and developing science lessons investigating microplastics for students in rural Oregon. This project will investigate how plastic type and the changing surface chemistry and morphology during environmental aging impact aerosol properties and processes. Using a wide variety of plastics commonly found in the environment, such as polyethylene, polystyrene, and nylon, Professor Bain and her team will age plastics in the lab and investigate the sorption of water and surface-active organic molecules to and from plastic surfaces. Additionally, they will develop new instrumentation to investigate the physical processes of mixed plastic-aqueous aerosol at the single particle level. Specifically, this project will investigate where these nano- and microplastics are located in mixed-phase systems, and how they might alter aerosol hygroscopicity and the partitioning of surface-active molecules. The education efforts will integrate technical computing into undergraduate analytical chemistry, where students will learn to work with large datasets and leverage AI to efficiently develop code for data analysis. Additionally, in collaboration with the SMILE (Science & Math Investigative Learning Experiences) program, a hands-on science lesson characterizing microplastics will be developed for middle and high school students. 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.