Abstract: Porous organosilicas with specific surface chemistries were developed as adsorbents for the selective removal of either perfluoroalkyl surfactants (PFASs) from water. Swellable organically modified silica (SOMS) materials were created that incorporated cationic and fluoroalkyl groups with the hypothesis that intermolecular interactions specific to PFASs would improve adsorption affinity and capacity. SOMS materials are useful in adsorbent design since they possess: i) the ability to swell to creates a continuous mesoporous structure, ii) a surface chemistry that can be tailored through synthesis or incorporation of polymer coatings to the pores, and iii) chemical stability to allow for regeneration in place. Adsorption kinetics, adsorption isotherms, and column breakthrough experiments were used to measure performance for a range of PFASs with variable chain length and chemical identity (PFDA, PFNA, PFOA, PFHpA, PFHxA, PFOeA, PFBA, PFOSA, PFxHs, PFOSA, and PFOSaAm). Organosilica materials show promise for allowing rational design of adsorbents used for remediation of PFAS impacted water.
Adsorption mechanisms unique to SOMS will be presented in the context of treatment of wide range of water solutes for those with general interest in water purification technology.
Biography: Paul Edmiston, the Theron and Dorothy Peterson Professor of Chemistry, is an analytical chemist at The College of Wooster (Ohio). His specialized area of research involves advanced materials for chemical separations as applied to environmental engineering. Dr. Edmiston has received several grants from the National Science Foundation including a NSF-CAREER award for research into the detection of explosives via molecularly engineered organosilica materials. Overall, Dr. Edmiston has received over $4.4 million in grant funding over the past 15 years. He was a Research Fellow at Georgia Tech working in collaboration with scientists at the GTRI Electrooptical Systems Laboratory integrating responsive organosilica sorbents with optical detection methods. He has served on the Committee of Visitors for the Chemistry Directorate at the National Science Foundation and was elected as a working group participant for the Materials Genome Initiative and is a member of National Science Foundation Advisory Committee (MPS) on the Nexus of Water and Agriculture. He is a member of the American Chemical Society and is Co-Chair of the ACS Division of Analytical Chemistry Graduate Fellowship Committee. He holds a BS in Chemistry from Pepperdine University and PhD in Analytical Chemistry from the University of Arizona.
Dr. Edmiston was also Chief Science Officer of ABS Materials Inc. from 2008-2016, a company he co-founded commercializing organosilica sorbents under the tradename Osorb®. There he helped commercialize materials developed for the analysis and treatment of flow back water and produced water with SBIR funding from the U.S. Department of Energy and NSF. Dr. Edmiston has 40 publications and 11 granted patents resulting from his work.