Abstract
We investigate the 3D structure and drying dynamics of complex mixtures of emulsion droplets and colloidal particles, using confocal microscopy. Air invades and rapidly collapses large emulsion droplets, forcing their contents into the surrounding porous particle pack at a rate proportional to the square of the droplet radius. By contrast, small droplets do not collapse, but remain intact and are merely deformed. A simple model coupling the Laplace pressure to Darcy’s law correctly estimates both the threshold radius separating these two behaviors, and the rate of large-droplet evacuation. Finally, we use these systems to make novel hierarchical structures.
- Received 29 July 2009
DOI:https://doi.org/10.1103/PhysRevLett.104.128303
©2010 American Physical Society
Synopsis
Drying out in 3D
Published 2 April 2010
As aqueous emulsions containing colloidal particles dry, two very different behaviors are observed.
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