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Seminar: Nanoscale Control of Density Inhomogeneity is Crucial to Optimize Polymer Membranes for Aqueous Separations

Speaker: Enrique D. Gomez, Professor of Chemical Engineering and Materials Science and Engineering, Pennsylvania State University

Host: Michael Toney

Tuesday, April 5, 2022 - 2:45 p.m. MT
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Seminar Abstract

Reverse osmosis modules comprised of composite polymer membranes represent a leading technology in desalination and purification of brackish water.Ìý Nanoporous polymeric membranes are key for prefiltering of such reverse osmosis systems, as well as for purification of biopharmaceutical products, such as monoclonal antibodies.Ìý The field has relied on intricate control of membrane properties through systematic perturbations to membrane chemistries and processing, yet many fundamental questions remain on the mechanisms that govern water transport and separations. We have leveraged advances in multi-modal electron microscopy to generate new insights on membrane structure and function.Ìý For example, we have combined the focused ion beam with scanning electron microscopy through serial sectioning to reconstruct a 3D representation of ultrafiltration membranes using for virus removal from biopharmaceutical streams.Ìý In addition, we have combined energy-filtered transmission electron microscopy with electron tomography from scanning transmission electron microscopy images to map the variation in density of polyamide films used in reverse osmosis membranes.Ìý Quantitative analyses of imaging products are key to extract mechanistic details that govern water transport and separations.Ìý Furthermore, we image membranes challenged with model and common foulants, to ascertain initial conditions and mechanisms for degradation of filtration performance.

Biosketch

Enrique D. Gomez received a B.S. in Chemical Engineering from the University of Florida in 2002, received a Ph.D. in Chemical Engineering from the University of California, Berkeley in 2007, and spent a year and a half as a postdoctoral research associate at Princeton University.Ìý Dr. Gomez joined the faculty at the Pennsylvania State University in August of 2009, where he is now a Professor of Chemical Engineering and Materials Science and Engineering. He also serves as the Associate Head for Diversity, Equity and Inclusion in the Department of Materials Science and Engineering. Research activities of Dr. Gomez are focused on connecting the chemical structure soft materials to macroscopic properties.Ìý To this end, the Gomez group pushes the limits of X-ray scattering and electron microscopy to refine descriptions of the microstructure of soft materials. The current emphasis of his research group is on the relationship between microstructure and electrical properties in the active layers of organic thin film transistors and photovoltaics, on elucidating the key factors that govern aqueous transport through water filtration membranes, and in the development of microstructure control to enable sustainable materials.Ìý Enrique has received multiple awards, including a Visiting Scientist Fellowship from the National Center for Electron Microscopy, the Ralph E. Powe Junior Faculty Award by the Oak Ridge Associated Universities, the National Science Foundation CAREER Award, the Rustum and Della Roy Innovation in Materials Research Award, the Penn State Engineering Alumni Society Outstanding Research Award, and the Arthur K. Doolittle Award of the American Chemical Society. He was also elected Fellow of the American Physical Society in 2021.