Seminar Date: Tuesday, March 12, 2024
Time: 11:00 am
Location: 67-3111 & Zoom
Talk Title: Electron videography for soft, biological, and energy matter
Zoom recording (available for 30 days)
Abstract:
I will discuss my group’s recent progress on adapting a suite of electron microscopy 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 phase behaviors of nano-sized building units as they are dispersed in solution. As a proof-of-concept, we directly image the crystallization pathways of nanosized colloids into superlattices, where the discreteness and multi-scale coupling effects complicate the free energy landscape. Single particle tracking and simulations combined unravel a series of interesting pathways at this length scale, such as non-classical crystallization, size-dependent crystal growth habits of superlattices, 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 real-time “fingering” fluctuations, which we attribute to dynamic rearrangement of lipid molecules wrapping the proteins. The conformational coordinates of protein transformation obtained from the movies are used as inputs in our molecular dynamics simulations, to verify the driving force underpinning the function-relevant fluctuation. In the third direction, we further push direct imaging to separation membranes and multivalent ion batteries, where the strain embedded heterogeneously within leads to morphogenesis and distinct charge transport properties. We foresee our suite of “electron videography” tools to provide crucial and complementary insights in various materials systems, with the common theme of imaging and manipulating materials in space and time at the nanoscale.
Bio:
Prof. Qian Chen is currently an Associate Professor and Racheff Scholar in the Materials Science and Engineering Department at University of Illinois at Urbana-Champaign (UIUC). She obtained her PhD from the same department with Prof. Steve Granick (2012), did her postdoc with Prof. Paul Alivisatos at
UC Berkeley under Miller Fellowship, and joined the faculty of UIUC in 2015. The research in her group focuses on imaging, understanding, and engineering materials at the nanoscale, including systems such as colloidal self-assembly, protein transformation, advanced battery devices, metamaterials, and energy-efficient separation membranes. Her group has received awards based on their research work such as Forbes 30 under 30 Science List (2016), AFOSR YIP award (2017), NSF CAREER award (2018), Sloan Research Fellow (2018), Unilever award in ACS (2018), the Hanwha-TotalEnergies IUPAC Young Scientist Award on Polymer Science (2022), the Soft Matter lectureship (2023), the Provost’s Award for Excellence in Graduate Student Mentoring (2024), and the Outstanding Early Career Investigator Award in MRS (2024).
