Date/Time
Date(s) - 02/01/2024
1:55 pm - 2:55 pm
Location
Rhines Hall 125
Categories
Abstract
The development and application of nuclear energy have created new elements which would otherwise be unavailable for study. These include transuranic elements (Np, Pu, Am, and Cm), which, unlike the lanthanides that are redox inert (with few exceptions where oxidation states ranging from +2 to +4 are possible), can exist in oxidation states as high as +7 to as low as +2.
Real-world application of our understanding of f-electron interactions can be exploited to develop a single-cycle actinide separation scheme for used fuel reprocessing, where U, Np, Pu, and Am, can be concurrently separated (as AnO22+). The key holdout in this regard is the generation of Am(VI) which is challenging due to the high one-electron oxidation potential for Am(III) (E(AmIV/III) = 2.62 V).
Wide bandgap semiconductor metal oxide electrodes are good candidates to adjust actinide oxidation states. They can operate electrochemically through the use of Ligand Modified Electrodes (LME). This approach involves derivatizing the surface of transparent conductive oxide thin films with ligands that bind actinides and facilitate their redox transformation. The same transparent conductive oxides can also be used as photoelectrodes where direct band-gap excitation generates an oxidizing environment, which can quantitatively generate higher oxidation state actinides in acidic solutions. The work presented here demonstrates new ways to generate, maintain, and study actinides in unusual oxidation states.
Bio
Christopher Dares, Ph.D.
Associate Professor
Florida International University
Dr. Christopher Dares is an associate professor in the Alan Levin Department of Mechanical and Nuclear Engineering at Kansas State University. Bahadori is a Steve Hsu Keystone Research Faculty Scholar and holds the Hal and Mary Siegele Professorship in Engineering. He earned BS degrees in mechanical engineering with nuclear engineering option and mathematics from Kansas State University in 2008, an MS in nuclear engineering sciences in 2010 from the University of Florida, and a PhD in biomedical engineering in 2012 from the University of Florida.
Bahadori was employed at NASA’s Lyndon B. Johnson Space Center from 2010 to 2015, with work focused on astronaut radiation risk projection and assessment, space radiation dosimetry using active pixel detectors, and space radiation transport using deterministic and Monte Carlo-based codes. He returned to Kansas State University as an assistant professor in 2015 and was promoted to associate professor with tenure in 2021, where he teaches courses in nuclear/radiological engineering and conducts research with focus areas in radiation protection, radiation transport applications, and semiconductor detector modeling and simulation. Bahadori has been certified in the comprehensive practice of health physics by the American Board of Health Physics since 2015.