Title:

Direct observation of nanoscale liquid-gas interfacial phenomena using liquid phase electron microscopy.

Speaker:

Prof. Yoko Tomo

Affiliation:

Department of Mechanical Engineering, Kyushu University, Japan

When:

Thursday, October 20, 2022 at 11:00:00 AM   Add to Calendar

Where:

MRDC Building, Room 3515

Host:

Dr. Srinivas Garimella
sgarimella@gatech.edu
404-894-7479

Abstract

Liquid-gas interfacial phenomena are among the most important phenomena for various fluidics systems. When systems are scaled down to the nanoscale, the interfaces are strongly affected by atomic and molecular interactions and show unique behaviors. We have focused on developing a direct observation method for the liquid-gas interface using liquid phase electron microscopy to understand how the nanoscale interactions affect fluidic behaviors. Using liquid cells, we observed nanobubbles’ generation and growth processes. The initial stage of the bubble growth was influenced by the Ostwald ripening effect. Moreover, we observed the instability of ultrathin water films confined within one-dimensional nanochannels. We explained the observed unique behavior by a theoretical analysis considering the effect of the van der Waals interaction between the thin water film and the wall. We suggested that the interactions could considerably reduce the fastest-growing wavelength when the film became thinner than a few nanometers.

Biography

Dr. Yoko Tomo is an Assistant Professor of Mechanical Engineering at Kyushu University, Japan. She is also a JSPS Overseas Research Fellow/Visiting Scholar at the Department of Chemical Engineering, Stanford University. She received her B.S. (2016) in Mechanical and Aerospace Engineering, M.S. (2017), and Ph.D. (2019) in Aeronautics and Astronautics from Kyushu University. She was a Visiting Student at Rice University in 2016 and the University of Edinburgh in 2018. Following her education, she joined the Department of Mechanical Engineering at Kyushu University as an Assistant Professor. Her research interests are nanoscale interfacial phenomena and heat transfer in fluids and soft materials. She recently received Japan Society of Mechanical Engineering Young Engineers Award and Young Researcher Award of the Heat Transfer Society of Japan. She gave a keynote talk at the 2021 micro Flow and Interfacial Phenomena (µFIP) Conference and an invited talk at the 13th Asian Thermophysical Properties Conference (2022ATPC).