ChBE Seminar: Revealing Materials Kinetics for Energy Applications by Synchrotron X-ray...
Speaker: Karen Chen-Wiegart, Assistant Professor, Materials Science & Chemical Engineering at Stony Brook University
Title: Revealing Materials Kinetics for Energy Applications by Synchrotron X-ray Nano-tomography and Multimodal Characterizations
Understanding the kinetics evolution of materials is crucial for designing materials for desired functions and properties. This includes studying materials for energy applications, which play a critical role in our modern energy technologies, spanning a wide range in functional materials such as in energy storage and conversion, as well as in structural materials such as in nuclear energy power plants. Multi-modal and multi-dimensional characterization with synchrotron X-rays can provide unprecedented information for complex, heterogeneous materials system. A multi-modal approach combines multiple synchrotron techniques to gain complementary structural, chemical and morphological information. These capabilities are particularly powerful when used to study complex structures with morphological and chemical heterogeneity.
In the seminar we will discuss how we use this synchrotron X-ray analysis in understanding two categories of materials systems: nano-/mesoporous metals created by dealloying; and batteries as energy storage materials. Synchrotron X-ray nano-tomography with operando analysis and chemical sensitivity helps us to fundamentally understand the processing-structure-property relationship in these complex materials. Dealloying, a selective etching process, can fabricate a variety of nano-/meso-porous metals with a characteristic bi-continuous structure with promising applications in catalysis, energy storage and bio-sensing. Synchrotron X-ray analysis has offered insights on understanding the morphological evolution of different dealloying systems, from solid-state interfacial dealloying to chemical dealloying and vapor phase dealloying. Most recently the method was also applied to understand the dealloying phenomena in molten salt corrosion. In energy storage materials, novel systems with nanoporous electrodes, lithium and beyond-lithium-ion batteries and aqueous batteries, will be discussed. The X-ray diffraction, spectroscopy and nano-tomography techniques together provide critical insights to connect the morphological changes in the batteries with the electrochemical processes and chemical reactions and structural evolution in the systems.
Prof. Chen-Wiegart, a professor of materials science and chemical engineering at Stony Brook University, emphasizes applying state-of-the-art x-ray imaging and spectroscopic techniques to study novel functional materials. Her current interests include energy storage and conversion, nano-/meso-porous materials, thin film & surface treatment, and cultural heritage. She also holds a Joint Appointment with National Synchrotron Light Source – II (NSLS-II) at Brookhaven National Laboratory (BNL), coordinating the efforts of multi-modal research approach.
Before joining the Department of Materials Science and Chemical Engineering at Stony Brook University, Chen-Wiegart served as beamline scientist at the Sub-Micron Resolution X-ray Spectroscopy (SRX) Beamline of NSLS-II. Prior to that she was a postdoctoral fellow at the National Synchrotron Light Source at BNL, where she participated in the commissioning of the new high-resolution x-ray transmission microscope and in establishing the new associated research program. Her PhD research at Northwestern University focused on the study of the dealloying and coarsening behaviors of nanoporous metal which has numerous potential applications, co-funded by Advanced Photon Source, Argonne National Laboratory. While continuing to develop cutting-edge x-ray tools, Chen-Wiegart is exploring new opportunities in functional materials. She has also been active in out-reach programs at NSLS-II and SBU, organizing events such as “Bring Our Children to Work Day” for the Photon Sciences Division at BNL, volunteering for educational and outreach events, and teaching courses in Women in Science & Engineering program at SBU.