Please join Yale Chemistry for a Silliman Seminar in Materials Chemistry with Qian Chen, Professor of Chemistry and Racheff Faculty Scholar in the Department of Materials Science and Engineering, University of Illinois Urbana-Champaign (UIUC).
Abstract: My group studies the spatiotemporal heterogeneity of materials and addresses the associated science and technological questions of how to image it, quantify it, understand it, and engineer it for new properties, from the finest atomic and molecular scale to the particle assembly and composite scale. Specifically, we adapt a suite of electron videography methods (e.g., liquid-phase TEM, electron tomography, 4D-STEM) and machine-learning based data-mining to synthetic soft, biological, and energy related systems. In the first direction, we focus on the synthesis and phase behaviors of colloidal nanoparticles. We image the crystallization pathways in solution, examining effects such as discrete molecular interaction and multi-scale coupling, which complicate the potential energy surface. By combining single particle tracking and simulations, we discover interesting chemical phenomena, such as non-classical nucleation, size-dependent crystal growth habits, and moiré patterning, enabling advanced crystal engineering. In the second direction, we study membrane proteins in their native lipid and liquid environment at the nanometer resolution. The proteins exhibit dynamic “fingering” due to the rearrangement of lipid molecules interacting with the proteins. The conformational changes obtained from videography inform our molecular dynamics simulations, which probe lipid-protein interactions. In the third direction, we further push direct imaging to separation membranes synthesized from interfacial polymerization as well as multivalent ion batteries, where microstructure heterogeneity leads to morphogenesis and distinct charge transport properties. Our studies on these systems reveal unified presence and importance of spatiotemporal heterogeneity in morphology, composition, structure, and function. Our suite of “electron videography” tools is foundational for imaging and manipulating materials in space and time at the nanoscale.
More information on Prof. Chen’s research can be found here: Chen Group
Faculty Host: Prof. Hailiang Wang
This seminar can be viewed online here: Panopto
This seminar is generously sponsored by the Mrs. Hepsa Ely Silliman Memorial Fund.