Abstract
When cooled down, emulsion droplets stabilized by a frozen interface of alkane molecules and surfactants have been observed to undergo a spectacular sequence of morphological transformations: from spheres to faceted liquid icosahedra, down to flattened liquid platelets. While generally ascribed to the interplay between the elasticity of the frozen interface and surface tension, the physical mechanisms underpinning these transitions have remained elusive, despite different theoretical pictures having been proposed in recent years. In this Letter, we introduce a comprehensive mechanical model of morphing emulsion droplets, which quantitatively accounts for various experimental observations, including the size scaling behavior of the faceting transition. Our analysis highlights the role of gravity and the spontaneous curvature of the frozen interface in determining the specific transition pathway.
- Received 14 September 2020
- Accepted 1 December 2020
DOI:https://doi.org/10.1103/PhysRevLett.126.038001
© 2021 American Physical Society
Physics Subject Headings (PhySH)
synopsis
The Strange Shapes of Cooling Droplets
Published 21 January 2021
Researchers uncover the mechanism that makes some oil droplets change shape from spheres to icosahedrons to flattened plates.
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