Chemical separations are crucial in refinery and reprocessing critical materials, such as platinum group metals, rare earths, and actinides. Typically, in these processes, the target metal ions adsorb or transfer across an aqueous interface, evident in solid/liquid interfaces in membranes and sorbents, and oil/water interfaces in liquid-liquid extraction (LLE). Despite the extensive use of these technologies for decades, our understanding of the molecular-scale mechanisms behind ion adsorption and transport at the interfaces is still limited. This lack of knowledge poses a challenge in meeting the rising demand for these critical materials, increasingly used in advanced technologies. However, recent advancements in surface-specific experimental and computational techniques are promising in addressing this gap, potentially revolutionizing next-generation separation systems. The model interfacial systems developed for studying chemical separations could have wide implications, aiding scientific inquiries beyond separations. In this talk, I will discuss some of these systems, including amphiphilic extractants and thin graphene oxide films at the air/water interface, and graphene electrodes under electrochemical control. These studies have provided crucial, molecular-scale insights into solute and solvent behaviors at aqueous interfaces.

Dr. Ahmet Uysal is a Chemist in the Chemical Sciences and Engineering Division of Argonne National Laboratory, USA. His research is focused on molecular-scale mechanisms in interfacial ion transfer, graphene-based 2D materials, ion–amphiphile interactions at aqueous interfaces, and chemical separations. He specializes in synchrotron X-ray scattering techniques and interface-specific nonlinear vibrational spectroscopy. He received his B.S., M.S., and Ph.D. degrees from Middle East Technical University, University of Pittsburgh, and Northwestern University, respectively. Uysal is a recipient of the US Department of Energy Early Career Award in 2019.