Tanaka Shinpei, Nakata Satoshi, Nagayama Masaharu
Graduate School of Advanced Science and Engineering, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima 739-8521, Japan.
Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, 739-8526, Japan.
Soft Matter. 2021 Jan 22;17(2):388-396. doi: 10.1039/d0sm01500h.
We report herein experimental observations of the reciprocating motion of a self-propelled droplet floating on the surface of an aqueous surfactant solution and a simple reaction model capable of reproducing the observed behavior of the droplet. The reciprocating motion was observed in a quasi-one-dimensional annular channel, so the reciprocation was not caused by reflections at boundaries. To understand the reciprocation, our model assumes a reaction between the surface active substance emitted from the droplet and surfactants dissolved in the aqueous solution. This reaction invokes an inversion of the surface tension gradient and thus the droplet's reciprocation. We show that the model can reproduce experimental results semi-quantitatively using numerical simulations with realistic parameters.
我们在此报告了对漂浮在表面活性剂水溶液表面的自驱动液滴往复运动的实验观察结果，以及一个能够重现液滴观察到的行为的简单反应模型。往复运动是在准一维环形通道中观察到的，因此这种往复不是由边界处的反射引起的。为了理解这种往复运动，我们的模型假设从液滴中释放出的表面活性物质与溶解在水溶液中的表面活性剂之间发生反应。这种反应引发表面张力梯度的反转，从而导致液滴的往复运动。我们表明，该模型使用具有实际参数的数值模拟能够半定量地重现实验结果。
