Particle Formation and Growth
An understanding of the initial stages of particle formation are critical in controlling particle formation processes. To map out the mechanisms of particle formation, an ability to measure the size resolved chemistry is required. A high resolution differential mobility analyzer has been used to measure newly detected sub 2nm clusters during the combustion synthesis of metal oxide nanoparticles. In addition, a tandem DMA-MS system has been developed to elucidate the initial stages of particle formation through electrical mobility separation of ions during combustion synthesis. Comparisons of measured electrical mobility with theoretical predictions of ion mobility allows for the detailed study of gas molecule interactions with ions and more precise predictions of collision cross-sections for different types of ions in the transition regime.
Isolated graphene crystals, which demonstrate exceptional electronic properties, extreme surface-area-to-volume ratio, and broad functionalization possibilities, are now being applied to a number of environmental technologies. By 'crumpling' graphene and graphene oxide via a simple aerosol method, it has been observed that the resulting three-dimensional (3D) structures have improved properties for environmental applications. The focus of this work is on developing an understanding of the fundamental mechanisms of aerosol synthesis of crumpled 3D graphene based materials. Through this understanding, materials are being developed for applications in CO2 photoreduction and water treatment membranes. Specifically, applications of graphene and TiO2 nanocomposites are being explored for CO2 photoreduction. In addition, the functionalization of water treatment membranes using crumpled graphene oxide-based nanomaterials is being undertaken. These systems are also being modeled to enable a better understanding of the system and optimization of the processes.
Another are of focus for environmental technology is smart water infrastructure. This research work focuses on developing multi-scale models to monitor water quality throughout drinking water distribution systems. Novel modeling techniques were developed for the transport phenomena and chemical reactions that result in bacterial growth and loss of disinfectant residuals in water distribution networks. The formation and transport of particulate matter and how it affects drinking water quality and user satisfaction is also being studied.