Dynamics and mechanism of quasi-two-dimensional foam droplets under gravity from microscopic and macroscopic perspective

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K14431
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 13040:Biophysics, chemical physics and soft matter physics-related
• Research Institution: Tokyo Metropolitan University
• Principal Investigator: Tani Marie 東京都立大学, 理学研究科, 助教 (10822950)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: ソフトマター / 泡沫 / ピンチオフ

Outline of Final Research Achievements

Liquid foam is a state where air bubbles are confined in a liquid. We use foam in our daily life, taking advantage of its unique and high functional properties, which differs from the pure liquid or the pure gas state. However, macroscopic deformation of foam is usually coupled with the microscopic rearrangement of air bubbles, which significantly increases the difficulty of the problem. Therefore, the dynamic and the mechanism of the macroscopic deformation of foam have not been clarified yet.
Here, we focused on the dynamics of the macroscopic behavior of a foam droplet under gravity. We found "pinch-off mode" where liquid draining from the foam pinches off, and "no pinch-off mode". In addition, the mode boundary was explained experimentally and theoretically.

Free Research Field

ソフトマター

Academic Significance and Societal Importance of the Research Achievements

我々は日常生活で泡沫を利用した製品を多く使用している一方で，泡沫のマクロな挙動に関して，学術的には未解明なことが多くある．また，本研究課題により，滴状の泡沫から液滴がちぎれる条件が明らかになったことは，壁や窓，シンクの洗浄などのために鉛直壁に泡沫を吹き付ける際に溶液の流出を防ぐ方策につながり，産業的にも，環境問題の観点からも，意義のある成果だと考えられる．