Tanabe Takahiro, Ogasawara Takuto, Suematsu Nobuhiko J
Meiji Institute for Advanced Study of Mathematical Sciences (MIMS), Meiji University, 4-21-1 Nakano, Nakano-ku, Tokyo 164-8252, Japan.
Graduate School of Advanced Mathematical Sciences, Meiji University, 4-21-1 Nakano, Nakano-ku, Tokyo 164-8525, Japan.
Phys Rev E. 2020 Aug;102(2-1):023102. doi: 10.1103/PhysRevE.102.023102.
We focus on the self-propelled motion of an oil droplet within an aqueous phase or an aqueous droplet within an oil phase, which originates from an interfacial chemical reaction of surfactant. The droplet motion has been explained by mathematical models, which require the assumption that the chemical reaction increases the interfacial tension. However, several experimental reports have demonstrated self-propelled motion with the chemical reaction decreasing the interfacial tension. Our motivation is to construct an improved mathematical model, which explains these experimental observations. In this process, we consider the concentrations of the reactant and product on the interface and of the reactant in the bulk. Our numerical calculations indicate that the droplet potentially moves in the cases of both an increase and a decrease in the interfacial tension. In addition, the reaction rate and size dependencies of the droplet speed observed in experiments were well reproduced using our model. These results indicate the potential of our model as a universal one for droplet motion.
我们关注油滴在水相中的自驱动运动或水滴在油相中的自驱动运动，这种运动源于表面活性剂的界面化学反应。液滴运动已通过数学模型进行解释，这些模型需要假设化学反应会增加界面张力。然而，一些实验报告表明，化学反应使界面张力降低时也会出现自驱动运动。我们的动机是构建一个改进的数学模型，以解释这些实验观察结果。在此过程中，我们考虑了界面上反应物和产物的浓度以及本体中反应物的浓度。我们的数值计算表明，在界面张力增加和降低的情况下，液滴都有可能移动。此外，使用我们的模型很好地再现了实验中观察到的液滴速度对反应速率和尺寸的依赖性。这些结果表明我们的模型有潜力成为一个通用的液滴运动模型。
