Thinning air-water films stabilized by bacterial particles——the Online First Article of Acta Mechanica Sinica

Journal Tittle: Acta Mechanica Sinica

Article Tittle: Thinning air-water films stabilized by bacterial particles

Author: Wu, Song; Yang, Yuehua; Jiang, Hongyuan

Novelty/impact/significance

1.      Develop a novel device to prepare free liquid films.

2.      Reveal two distinct film evaporation dynamics.

3.      Prove that the evaporation dynamics of film are not affected by the active motility of bacteria.

Scientific question

We have answered how the concentration of the bacterial solution affects the evolution of the shapes and stabilities of liquid films.

Key of how

The dynamic movements of bacterial particles on free liquid films during evaporation is quantified by direct microscopic observation. To reveal the mechanism of bacterial movement, the lateral capillary force of particles at different positions on the liquid film is theoretically analysed.

Major points

1.       We find that the liquid film with a low bacterial concentration exhibits a drainage and rupture process similar to pure water.

2.       We find that bacteria form a single-layer array in the center region of the film and greatly enhance the stability of the liquid film when the bacterial concentration is high.

3.       We find that the two distinct film evaporation dynamics are caused by the difference in the lateral capillary force of the particles at different positions on the liquid film.

4.       We show that the stability of the liquid film and the evaporation dynamics of film are not affected by the active motility of bacteria.

Funding of the work

1.       The National Natural Science Foundation of China (Grants No. 11872357, 11622222, and 12002338);

2.       The Fundamental Research Funds for the Central Universities, the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB22040403);

3.       The National Postdoctoral Program for Innovative Talents (Grants No. BX20190318), the China Postdoctoral Science Foundation (Grants No. 2019M662188);

4.       The USTC Research Funds of the Double First-Class Initiative (Grants No. YD2480002001);

5.      The Anhui Provincial Natural Science Foundation (Grants No. 2008085QA24).

Please go to the website to read this article: http://ams.cstam.org.cn/EN/abstract/abstract157344.shtml#