Fractals/Dendrites and the Dissolving of Phenoxyethanol in Water

[nik282000]

TL;DR

Phenoxyethanol (1-Hydroxy-2-phenoxyethane) forms fractal patterns as it dissolves in water. I don't know why, do you?

I shot some high speed footage of phenoxyethanol dissolving into water and observed some fractal/dendrite like patters at the edge of thin droplets that float on the surface of the water.

I suspect that the water under the droplet becomes saturated very quickly as the phenoxyethanol is not extremely soluble and that the surface tension of the water around the droplet is lowered by the phenoxyethanol. This would mean that the only way more phenoxyethanol could dissolve is if unsaturated water is drawn up from below the droplet towards the edges and that the length of that edge determines the rate of dissolving. Forming a fractal/dendrite pattern would maximize the edge length and rate at which the phenoxyethanol dissolves but I'm not sure why this would happen instead of a uniform smooth edge or any other profile.

In the video you can see that the fractal/dendrite edge is reduced or disappears completely when two droplets approach which supports the idea that the water becomes locally saturated and that surface tension changes as the phenoxyethanol dissolves. However, I am not a scientist and would love to know if this is an already known/named phenomena.

 

[Klystron]

Thanks for showing this interesting effect. Even if the images only resemble fractals / dendrites, they capture a certain liveliness reminiscent of waterborne life forms such as paramecium.

 

[nik282000]

Thanks for showing this interesting effect. Even if the images only resemble fractals / dendrites, they capture a certain liveliness reminiscent of waterborne life forms such as paramecium.

View attachment 298987

Yes! The little arms look very much like they are covered in cilia! When I set the camera up again I'll try to see how small they really get. The largest wiggle around 50-100hz and the smaller ones seem to go even faster, I might have to crank my camera up to the max to see the smallest features.