Early stages of particle formation in high temperature aerosol reactors
Aerosol science and technology enable continual advances in material synthesis and atmospheric pollutant control. Among these advances, one important frontier is characterizing the initial stages of particle formation by real time measurement of particles below 2 nm in size. Sub 2 nm particles play important roles by acting as seeds for particle growth, ultimately determining the final properties of the generated particles. Tailoring nanoparticle properties requires a thorough understanding and precise control of the particle formation processes, which in turn requires characterizing nanoparticle formation from the initial stages. The knowledge on particle formation in early stages can also be applied in quantum dot synthesis and material doping. This project pursued two approaches in investigating incipient particle characterization in systems with aerosol formation and growth: (1) using a high-resolution differential mobility analyzer (DMA) to measure the size distributions of sub 2 nm particles generated from high-temperature aerosol reactors, and (2) analyzing the physical and chemical pathways of aerosol formation during combustion.
Thermal remediation: unraveling the fate of per- and polyfluoroalkyl substances (PFAS) in contaminated soil during lab-scale incineration processes
Per- and Polyfluoroalkyl Substances (PFAS) are a large group of chemicals used in numerous industrial and consumer applications, and they have recently been identified as a major human health threat. Over 100 PFAS-contaminated sites have been identified in Florida, and many contaminated locations, such as firefighting training sites, military installations, and dry cleaners, are expected to require soil remediation. Traditional soil remediation technologies are ineffective for PFAS treatment; however, preliminary research into high-temperature thermal treatment has shown promise. In collaboration with the University of Florida, we aim to develop a mechanistic understanding of the (a) desorption and decomposition of PFAS from contaminated soil and (b) their destruction pathways utilizing lab-scale thermal treatment processes. The physicochemical properties of the particulate and gaseous components generated from the incineration processes will be obtained from controlled experiments performed in furnace and flame reactors. This data can then be used to design robust thermal treatment processes for deployment of effective and safe PFAS destruction methodology in large-scale soil remediation systems.
Combustion synthesis of functional nanoparticles for energy and environmental applications
Compared to conventional approaches for the manufacture of nanoparticles, gas-phase synthesis offers the advantages of high-throughput production, fast processing, and simplicity. Wide applications of these nanomaterials can be found in energy and environmental engineering, and new fields of nanomedicine and nanorobotics have emerged and are expected to flourish. Recent applications of gas-phase synthesized nanomaterials in energy conversion include solar cells, lithium batteries, CO2 photo-reduction, and catalytic combustion of volatile organic compounds. In these applications, the nanomaterials act as a medium for the transport of electrons and ions or as a catalyst promoting the reaction rates. Their properties are a strong function of their structures, and the successful application of gas-phase synthesis requires an adequate degree of tailoring and control of these structures. By controlling the synthesis method, temperature, composition, and reaction time, the structure of the nanomaterials can be fine-tuned for better performances in energy conversion applications. Modeling approaches are also developed to validate the synthesis techniques.
Conference presentations:
Titanium Dioxide and Silicon Dioxide Formation in Corona Discharge Assisted Combustion (2024)
Funded projects:
Ultrafine Inorganic Particle Formation in Plasma-Assisted Combustion (NSF: 2021-2024)
Thermal remediation: unraveling the fate of per- and polyfluoroalkyl substances (PFAS) in contaminated soil during lab-scale incineration processes (Florida Department of Environmental Protection: 2024 to 2025)
