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Mode Selection in the Spontaneous Motion of an Alcohol Droplet

Ken Nagai·Yutaka Sumino·Hiroyuki Kitahata·Kenichi Yoshikawa
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Abstract

An alcohol (pentanol) droplet exhibits spontaneous agitation on an aqueous solution, driven by a solutal Marangoni effect. We found that the droplet's mode of motion is controlled by its volume. A droplet with a volume of less than $0.1 μ\rm{l}$ shows irregular translational motion, whereas intermediate-sized droplets of $0.1-200 μ\rm{l}$ show vectorial motion. When the volume is above $300 μ\rm{l}$, the droplet splits into smaller drops. These experimental results regarding mode selection are interpreted in terms of the wave number selection depending on the droplet volume.

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Ken Nagai, Yutaka Sumino, Hiroyuki Kitahata, Kenichi Yoshikawa. 2005-04-21. Mode Selection in the Spontaneous Motion of an Alcohol Droplet. https://doi.org/10.1103/physreve.71.065301

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