Date: Wednesday, October 1
Time: 9:30-10:30AM
Location: Health Science Technology Building (HST), Forum Room 101
This event features Enrique Gomez, who will talk about "Cryo-EM Reveals Structure and Assembly of Polymer Mixed Conductors" as part of the Lehigh University Chemical and Biomolecular Engineering's Colloquium Seminar Series.
Abstract
Polymeric mixed ion-electron conductors are emerging as key materials for a variety of electrochemical devices, including bioelectronics. The ability to transport both ions and electrons often requires an intricate and multiscale structure, but characterization of that structure remains a challenge. Our work has focused on electron microscopy, complemented by X-ray scattering, to reveal chain packing and mesoscale assembly of mixed conductors used in biodevices and biosensors. High resolution transmission electron microscopy reveals chain packing of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) in solution and in films that are dry or hydrated. This approach reveals how solution aggregates lead to intricate microstructures in films, and how swelling affects morphology. 3D reconstructions from electron tomography reveal new aspects of the out-of-plane structure, including layering that can be perturbed through salt additives. Altogether, our work shows how the multiscale structure impacts various key properties, including mechanical response and charge transport.
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