10:30 - 11:00 a.m. Coffee with speaker | 11:00 a.m. - 12:00 p.m. Seminar
"Transport and Local Dynamics in Hydrated Polymer Networks: Advanced NMR Approaches to Ion and Water Motion"
Oscar Nordness, Assistant Professor, Department of Earth and Environmental Engineering, Columbia University
Abstract: Polymeric membranes are essential materials for a diverse range of separation processes, from reverse osmosis to pharmaceutical purification. Yet, despite their ubiquity, the vast majority of conventional polymeric membrane materials lack the requisite selectivity to tackle emerging separation challenges posed by the treatment of nontraditional source waters, including urban wastewater, produced water, and mining leachate. In this context, the development of next-generation polymer membranes hinges on a comprehensive understanding of molecular-level interactions that cannot be readily characterized using traditional measurements. NMR spectroscopy provides a powerful, non-invasive approach for characterizing the transport and local dynamics within a variety of materials. In this seminar, we will explore how advanced NMR techniques, including pulsed-field gradient (PFG) NMR and NMR relaxometry, can be used in conjunction with traditional measurements to elucidate ion, water, and polymer behavior in a series of model polymer systems spanning the aqueous oligomers used in molecular dynamics simulations to crosslinked polymeric membranes, establishing a direct experimental bridge between the molecular length scales accessible to simulation and the macroscopic transport of a working membrane.
Bio: Oscar Nordness is an Assistant Professor in the Department of Earth and Environmental Engineering at Columbia University. Prior to joining Columbia in 2023, he received his PhD in Chemical Engineering from the University of Texas at Austin and worked as a postdoctoral fellow at UC Santa Barbara. His research focuses on elucidating the chemical mechanisms underpinning the behavior of complex electrolytes, including ionic liquids, polymer electrolytes, and polymer membranes. To accomplish this, the Nordness lab employs advanced NMR spectroscopy techniques including pulsed-field gradient NMR, NMR relaxometry, and electrophoretic NMR in conjunction with data science and machine learning approaches.