NSF Award
2308858
This award supports a collaborative project between North Carolina State University, Clarkson University, and Texas A&M University to explore chemical reaction pathways in low temperature plasmas. The field of low temperature plasmas (LTPs) encompasses applications ranging from microelectronics fabrication and human implants to lasers and solar cell manufacturing. The success of the development of these technologies relies on the reactions of plasma-generated ions and free radicals. While extensive work has been conducted to identify and quantify reactive oxygen and nitrogen species, the generation mechanisms and subsequent reactions of non-oxidative species such as ions and metastable atoms produced by the plasma are largely unknown. These species have been proposed to be deployed for a range of unique plasmochemical transformations, including the removal of toxic per- and polyfluoroalkyl substances (PFAS) known as ''forever chemicals'' from water using multiphase gas-liquid plasma reactors. This project aims to accelerate the development and scale up of plasma reactors to degrade and destroy PFAS, and is supported under the ECosystem for Leading Innovation in Plasma Science and Engineering (ECLIPSE) and Critical Aspects of Sustainability (CAS): Innovative Solutions to Sustainable Chemistry (CAS-SC) programs. <br/><br/>The project seeks to elucidate non-oxidative chemical reaction mechanisms and pathways of photons, metastables, radicals, and charged particles generated by atmospheric pressure plasmas in contact with liquid water. The central approach for achieving these objectives involves measuring removal rates of four nonoxidizable fluorinated compounds in three gas-liquid plasma reactors of well-defined hydrodynamics and correlating them to the fluxes delivered from two different atmospheric pressure plasma jet devices. The central hypothesis of this effort is that solvated electrons and hydrogen radicals are the key species involved in non-oxidative chemical transformations. The mechanisms underlying the degradation of short-chain PFAS are of particular interest, as these compounds have proven to be extremely challenging to treat. This project involves students at all levels, from K-12 to graduate, including those from under-served communities. Major activities include development of a portable plasma-water demonstration setup for high school students, organization of a Chemical Engineering Workshop at a local children’s museum, participation in plasma summer schools, and utilizing social media platforms to create a series of exciting and engaging technical videos to encourage public interest in science.<br/><br/>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.
