Limonene and its derivatives are naturally occurring volatile organic compounds (VOCs) that largely contribute to the formation of secondary organic aerosol (SOA). SOA contributes to particle growth and also affects cloud formation and human health. Understanding the growth and formation of SOA improves our understanding of VOC oxidation. This is important for predicting air quality, SOA formation, and the impacts on the environment. We study the formation of SOA particles in a flow reactor by measuring the growth of a seed particle in the presence of limonene (or one of its derivatives) and the gas phase oxidant OH, generated via photolysis of HONO. We also consider how the acidity of the seed particle affects SOA generation. Initial results show an increase in the SOA yield with the oxidation of the limonene derivative. Our data shows another SOA mechanism, a chemical or physical uptake of some organics onto sulfuric acid seed particles without OH radicals.

Electron donor-acceptor (EDA) complexes are defined by their ability to absorb visible light. A single-electron transfer event in the complex, triggered by light excitation, generates radical ion intermediates. The formation of EDA complexes is of interest, as it generates radicals in mild conditions without the use of expensive photocatalysts using bench-stable substrates. This research began by employing density functional theory (DFT) to calculate steric and electronic descriptors of synthetically relevant molecules, such as Katritzky salts. A machine learning model, using a classification algorithm, then predicted the formation of EDA complexes. These predictions were verified experimentally to improve the efficacy of the model. Overall, this project investigated the formation of EDA complexes from Katritzky salts using a model with future widespread scientific use to aid the design of new reactions in organic chemistry.

Polymers, or plastics, typically fall into two categories: thermosets, which are strong and heat-resistant but non-recyclable, and thermoplastics, which are recyclable but mechanically weaker. In the past decade, researchers have developed a new class of polymers—Covalent Adaptable Networks (CANs)—that combine the strengths of both. CANs maintain the durability of thermosets while allowing reshaping and recycling like thermoplastics. In this ongoing project, we explore a novel synthesis method that uses formamide-functionalized methacrylate (FEMA) to create polyimine CANs. This approach broadens monomer compatibility and enables more convenient and versatile fabrication of CANs.

Structurally engineered for their unique chemical properties, per- and polyfluoroalkyl substances (PFAS) are widely used in industrial and consumer applications. However, the same properties that make them commercially valuable, such as thermal stability, hydrophobicity, lipophobicity, and surfactant behaviors, also contribute to poorly understood consequences. These range from environmental persistence to system-wide biological disruption. Their bioaccumulation and competitive binding behaviors are largely attributed to their fluorinated alkyl structure, which confers exceptional conformational stability and long biological half-lives. Now detected in the bloodstreams of nearly all Americans, it is imperative to understand how their molecular architecture governs receptor interactions and binding before large-scale health effects become irreversible. In particular, their capacity to disrupt signaling pathways mediated by peroxisome proliferator-activated receptors (PPARs) has linked them to thyroid dysfunction, hepatotoxicity, and carcinogenesis. To better understand their biological and toxicological implications, this study employs ab initio quantum mechanical calculations and free energy perturbation methods to characterize PFAS-PPAR interactions. The objective of the project is to generate and refine molecular mechanics force field parameters informed by quantum mechanical data to support accurate molecular dynamics simulations.