Environmental Engineering Implications and Applications of Carbon-Base Nanomaterials
Speaker: Debora F. Rodrigues, University of Houston, TX
Series: CEE Departmental Seminars
Location: Bowen Hall Auditorium
Date/Time: Monday, February 17, 2014, 12:00 p.m. - 2:00 p.m.
Carbon-based nanomaterials, such as carbon nanotubes, graphene, and graphene oxide, have unique antimicrobial, physical, chemical, electrical, optical and mechanical properties that make them very valuable materials for materials science, high-energy physics, and a wide range of technological applications. In fact, the market for carbon-based nanomaterial products is projected to reach nearly $675 million by 2020. If nanomaterials are to be widely utilized, they will find their way into the environment through human activities, wastewater discharge, industrial effluents, and runoff from nearby contaminated land. Aquatic systems are expected to be the ultimate repository for nanomaterials, which poses a special concern because aquatic systems are composed of diverse microorganisms that keep the aquatic environment ecologically balanced. These microorganisms are also responsible for removing unwanted wastes released into the wastewater treatment system through various biogeochemical cycles, such as nitrogen, phosphorous, sulfur, and carbon cycles. The theme of my research is to understand the toxicological mechanisms and effects on microbial biogeochemical cycles of emerging graphene-based nanomaterials. Additionally, I investigate alternative solutions to reduce the use of these nanomaterials, and therefore reduce their release into the environment. The approach used by my research group is the utilization of polymers, such as polyvinyl-N-carbazole (PVK), to develop nanocomposites. These nanocomposites contain small amounts of carbon-based nanomaterials as fillers within the polymer matrix. The PVK polymer was selected to generate carbon-based nanocomposites since it stabilizes the dispersion of the nanomaterials in any solution chemistry due to π - π interaction of the PVK carbazole group with the aromatic rings of the carbon-based nanomaterials. The well-dispersed nanocomposite can, then, be easily used to modify membranes for water purification. These modified membranes are much more efficient in the inactivation and removal of viruses and bacteria from water than unmodified ones. In this study, we demonstrate that it is possible to reduce the amount of nanomaterials whithin a polymer matrix and still produce more efficient water purification systems.
Debora F. Rodrigues received her BS and MS in Biology and Microbiology, respectively, from the University of Sao Paulo, Brazil, and her PhD in Microbiology and Molecular Genetics from Michigan State University in 2007 under the supervision of Prof. James Tiedje. In her MS research she demonstrated the presence of genes involved in the degradation of polychlorinated biphenyls (PCBs) and hydrocarbons in Brazilian estuaries. Her PhD work focused on the physiology and diversity of microorganisms in the Siberian permafrost. She was a postdoctoral associate in the Environmental Engineering Program at Yale University in the group of Prof. Menachem Elimelech from 2007 to June 2010. Her research at Yale dealt with toxicity of carbon nanotubes to microorganisms as well as the effect of bacterial surface structures on bacterial adhesion and biofilm formation and maturation. She is currently an Assistant Professor at the University of Houston in the Department of Civil and Environmental Engineering. Her research interests involve investigation of the toxicological effects of carbon-based nanomaterials and polymer nanocomposites to wastewater microbial communities and their potential applications for water treatment and corrosion prevention.