RUI: Thermodynamics of Secondary Aerosol Formation: The Role of Binary and Ternary Nucleation

Bucknell University, Lewisburg PA

Investigators

Abstract

The Environmental Chemical Sciences Program in the Chemistry Division at the National Science Foundation supports the research of Professor George C. Shields at Bucknell University for an NSF-RUI program to support four undergraduates in a summer research experience for three summers and a postdoctoral research associate for three years. In an effort to understand the initial stages of secondary aerosol formation, the proposed research will study the most important binary system in the atmosphere, H2SO4-H2O. Combining molecular dynamics sampling and high level quantum chemical methods, the minimum energy structures and the thermodynamics of formation of small molecular clusters will be determined. The critical cluster size and abundance of the clusters will be calculated for conditions relevant to the atmosphere. As the binary H2SO4-H2O itself is not sufficient to explain aerosol formation rates in the atmosphere, the same methodology will be applied to the ternary H2SO4-ammonia-H2O, H2SO4-amine-H2O, and H2SO4-ammonia-amine-H2O systems, which have been shown to enhance the formation of aerosols. The calculated trends in thermodynamics of cluster formation will be compared with nucleation rates provided by the principle investigator's experimental collaborator. A significant number of undergraduates, including women students and minorities, will have the opportunity to work side-by-side with the principle investigator on meaningful research projects in a highly mentored environment. Students will receive and benefit from intensive training in computational chemistry, and from this experience will develop skill sets and understanding of the research process that will serve them well in their scientific careers. A postdoctoral associate will learn how to develop a meaningful and productive research program with undergraduate research students and as the only computational chemist in the department, Professor Shields will expand the exposure and scope of research and collaborative opportunities for students and faculty in the department.