What you see here, despite appearances, is not a soap film. On the contrary, this is a thin vertical film made up of melted polymers. Like a soap film, it is extremely thin, varying from a few nanometers at its thinnest to several hundred nanometers at the thickest point. But unlike a freestanding soap film, this polymer film can last for more than a day before the film breaks. Researchers attribute the long life of the films to structural forces inside the fluid.
They observed that the films remain highly stratified, varying smoothly in thickness from their thinnest point at the top to the thickest point at the bottom. They hypothesize that the geometry of the film preferentially traps the polymer’s molecules in preferred orientations, which reinforces the stratification and helps stabilize the film. For more, check out the research paper. (Image credit: T. Gaillard et. al., source; via KeSimpulan)