The real environment is full of gas-solid and gas-liquid phase interfaces, and these processes influence our environment in many different ways. Atmospheric chemists have been interested in surface-mediated chemical reactions since the late 1980's, when this type of chemistry was found to play an important role in forming the Stratospheric Ozone Hole. While research has continued to illustrate the influence of heterogeneous chemistry on the composition of the atmospheric gas phase, larger questions about the the impact of multiphase reactions on the condensed (solid or liquid) phase remain. Many studies to date have probed the chemical reaction of one trace gas with one solid or liquid chemical component. Real environmental surfaces can contain thousands of compounds (throughout all phases). Our group is advancing scientific knowledge by working with increasingly complex chemical films, investigating temporally dynamic alterations to surface film composition, and exploring the impact of reactive gas mixtures in contact with organic surface films.
We are currently applying our approaches to studying questions relevant to the chemistry of indoor environments, especially as they pertain to recent changes in disinfection behavior and air cleaning. We are interested in how disinfection processes could introduce new multiphase chemistry to indoor spaces and potentially transform the chemical exposure profile for those who inhabit the space. Our studies are fundamental in their approach and therefore can also educate our understanding of atmospheric aerosol particles, the inner surfaces of our lungs, the human skin surface, the ocean surface (air-sea interface), and other biospheric surfaces relevant to ecosystem and human health.
For more information about environmental chemistry at gas-liquid interfaces, see the tutorial book chapter, "Gas-Liquid Interfaces in the Atmosphere: Impacts, Complexity, and Challenges" by Prof. Collins and Prof. Vicki Grassian (UC San Diego), found in Physical Chemistry of Gas-Liquid Interfaces (J.E. House and J.A. Faust, eds).
For background on the connections between indoor and outdoor atmospheric chemistry, see the book chapter entitled "Indoor Air Quality throught the Lens of Outdoor Atmospheric Chemistry" by Prof. Jon Abbatt (U of Toronto) and Prof. Collins, found in the Handbook of Indoor Air Quality (Y. Zhang, P.K. Hopke, C. Mandin, eds).
Pennsylvania's history and economy is inextricable with resource extraction. For centuries, anthracite coal has been actively mined in regions to the east of where Bucknell is located. While some mining activities continue today, many areas in the Coal Region bear the marks of abandoned coal mine lands. Public health outcomes for residents of the Coal Region are remarkably disparate from the surrounding communities; rates of heart disease, asthma, and cancer are among the highest in the state, and life expectancies are among the lowest. In a collaborative effort with Prof. Dabrina Dutcher (Chemistry & Chemical Engineering) and Dr. Shaunna Barnhart (Place Studies Program Director, BCSE), we are partnering with local community organizations, governments, and school districts to deploy a sensor network to make some of the first publicly available, continuous air quality measurements in the Coal Region. Through community partnerships we will engage in outreach and educational activities to build understanding and capacity in making environmental measurements in support of public health.
We are leveraging our community-engaged work on long-standing partnerships built through Coal Region Field Station, managed through the Bucknell Center for Sustainability and the Environment.
A team of Computer Science students have joined in for the Senior Design project to build out a database and public-facing dashboard for the air quality sensor network. At the end of the 2025-26 academic year, the data-centric efforts will blend into a student/faculty project guided by the Dominguez Center for Data Science.
While many people are familiar with the flashing signal produced by nocturnal fireflies in the summer, many related firefly species lack the ability to produce light and use other means to find mates. In a multi-disciplinary collaboration with Prof. Lower (Bucknell, Biology) and Prof. Pask (Middlebury College, Biology), our group is working to understand the nature of volatile and surface-bound chemical signaling agents in fireflies.
We use a variety of analytical techniques in our group, but our research is centered mostly around using mass spectrometry to study chemically complex environmental systems. Samples may be generated through laboratory experiments or may be collected from field sites out in the real world. Our lab is also developing new ways to introduce samples to mass spectrometers. Bucknell has an impressive suite of instrumentation that we use to conduct our research, including:
Liquid Chromatograph/Ion Mobility Quadrupole-Time-of-Flight Tandem Mass Spectrometer (Agilent 6560; LC-IM-Q-ToF)
Liquid Chromatograph/High-Resolution Mass Spectrometer (Thermo Scientific Exactive Orbitrap; LC-HRMS)
Thermal Desorption coupled to Gas Chromatograph/Mass Spectrometer (Agilent 8860/5977B; TD-GC-MS)
Atmospheric Solids Analysis Probe coupled to Quadrupole Mass Spectrometer (Advion expressIon-L; ASAP-MS)