open access

https://doi.org/10.14943/doctoral.k14640

https://hdl.handle.net/2115/83460

界面活性溶液上の自走油滴の集団運動に対する反応拡散-粒子モデルの研究

英語

2021-09-24

Hokkaido University

87p

We experimentally and numerically investigate collective behaviors of oil droplets floating on a surfactant solution in a narrow circular channel. A closed environment where a glass cover is placed on the channel shows that ethyl salicylate droplets on the surface of sodium dodecyl sulfate solution exhibit transient oscillatory dynamics, leading to the formation of a single cluster via the merging of sub-clusters. When the glass cover is removed, oscillatory behavior resumes, and the cluster breaks up. To understand these experimental findings, we introduce a mathematical model that combines equations of motion for droplets with a reaction-diffusion system, where droplet dynamics and the chemical reactions are considered on the one-dimensional surface, and the diffusion of chemicals in the air phase and the water phase is treated in the two-dimensional region. Our model successfully reproduces transient oscillations and the characteristics of cluster formation, and the effect of the glass cover. We argue that the long-range attractive interaction due to the global concentration profile of the solution suffices for the cluster formation.

2021-09-24

甲第14640号

博士(理学)

(主査) 教授 長山 雅晴, 教授 栄 伸一郎, 准教授 田﨑 創平

理学院（数学専攻）

博士論文

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