Fate of Environmental Contaminants and Materials Research through Computational Chemistry Approaches

Shukla, Manoj (US Army ERDC)

Advanced Materials Development

This presentation will highlight our computational chemistry research on the development of polymer nanocomposite materials, fate of contaminants in the environment and vital role played by HPC resources on our research. Further, this presentation will also highlight our current effort in understanding complex environmental factors that will contribute to Army's potential operations in the complex urban environments. Polyamide 6 (PA6) also known as nylon 6 is a semi-crystalline thermoplastic material. It is used in several applications due to high strength, good chemical resistance, and excellent wear/abrasion resistance. Carbon nanomaterials such as graphene (G) and carbon nanotube (CNT), due to their excellent physical and mechanical properties, are considered as an excellent reinforcing filler for the development of high-performance polymer nanocomposites. We used molecular dynamics (MD) simulations to predict the mechanical properties PA6-CNT/G nanocomposites as a function of CNT/G loading. Our calculation predicted that graphene could be used as a natural dispersant of carbon nanotube in the development of polymer nanocomposite. Per- and polyfluoroalkyl substances (PFASs) have been used heavily in military as aqueous film forming foams (AFFF) for fire training and emergency response purposes. The Department of Defense (DoD) has potential $2 billion estimated liability associated with PFAS contaminated sites. Munitions compounds once in the environment through various activities can degrade and resulting daughter products could be potentially more hazardous than the parent compound. Using computational chemistry approaches, we studied potential degradation of PFAS compounds and role of graphene oxide for PFAS removal from the water. This presentation will also discuss our work on the adsorption of some munitions compounds on α-alumina and iron(III) oxide surfaces. We found that solar energy would enhance the environmental degradation of munition compounds.