Study on the interfacial phenomenon inside the nanoscale space.

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K23490
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0301:Mechanics of materials, production engineering, design engineering, fluid engineering, thermal engineering, mechanical dynamics, robotics, aerospace engineering, marine and maritime engineering, and related fields
• Research Institution: Kyushu University
• Principal Investigator: Tomo Yoko 九州大学, 工学研究院, 助教 (70844273)
• Project Period (FY): 2019-08-30 – 2021-03-31
• Keywords: ナノフルイディクス / 液中TEM観察 / 気液界面 / ナノバブル / 透過型電子顕微鏡 / その場観察

Outline of Final Research Achievements

We investigated the nanoscale interfacial phenomena using liquid-phase transmission electron microscopy. Inside a carbon nanotube (CNT) or a graphene nanoscroll (GNS), the interfacial morphology depends on the solid surface's wettability and structure. Moreover, we observed that the annular liquid layer adhered to the GNS became unstable and broke down into bumps at regular intervals. We found that the interfacial instability could be affected by the van der Waals more than the surface tension when the film thickness was less than a few nanometers.
We also observed nanobubble coalescence on a silicon nitride membrane. We developed an image analysis that reconstructs two-dimensional TEM images into three-dimensional images. Using the technique, we found that the liquid film between bubbles kept its width, and the bubbles began to marge from the solid surface.

Free Research Field

熱工学

Academic Significance and Societal Importance of the Research Achievements

本研究は、ナノスケールで発現する流体現象を利用した電子機器向けの冷却システムの高効率化を目指し、その基礎的な物理機構を明らかにすることを目的とした。本研究により、これまで見ることができなかったナノスケールの流体現象の直接観察に成功し、気液界面現象について一定の知見を得た。さらに、本研究では、透過型電子顕微鏡像を三次元的に構築する新しい画像手法も開発し、今後の幅広い応用が期待される。