Dr. Nathalie A. Wall, Professor in the Department of Materials Science and Engineering at the University of Florida will give a seminar titlled "Synthesis and Characterization of Organoclays for the Sequestration of Technetium and Iodine" to the interested faculty and students at Discovery Park.

Abstract

Clay buffer materials serve as engineered barriers in nuclear waste repo helping to limit radionuclide transport following the degradation of waste canisters. Bentonite, primarily composed of crystalline smectite-group clay minerals such as montmorillonite, effectively sequesters cationic fission products due to its low zero point of charge (pHPZC). However, to capture anionic species like pertechnetate, iodide, and iodate, bentonite must be functionalized to modify its surface charge. This study explores the behavior of organoclays functionalized with alkylammonium cations of varying sizes and their applications in radionuclide sequestration, with a focus on technetium and iodine immobilization. Experimental results indicate that organometallic and iron-functionalized clays significantly enhance pertechnetate sequestration, presenting promising solutions for environmental remediation. By characterizing the structural and chemical properties of these modified clays, we demonstrate how targeted functionalization improves retention efficiency.

Bio

Nathalie A. Wall is a Tenured Professor and Interim Director of the Nuclear Engineering Program at the University of Florida. Her research focuses on the environmental behavior of radionu-clides, with applications in the nuclear fuel cycle and nuclear forensics. A Fellow of the Ameri-can Association for the Advancement of Science, she has been an active member of the ACS Nuclear Chemistry Division for many years.

Originally from France, Wall earned an undergraduate degree in Physical Sciences and a doctor-ate in radiochemistry from the University of Paris, followed by a postdoctoral research appoint-ment at Florida State University. She has worked in the Department of Nuclear Waste Manage-ment at the Commissariat à l’Énergie Atomique (CEA, the French Alternative Energies and Atomic Energy Commission) and as a staff scientist at Sandia National Laboratories. Before join-ing the University of Florida in 2019, she was a faculty member in the Chemistry Department at Washington State University.