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Microstructure, Morphology, and Lifetime of Armored Bubbles Exposed to Surfactants
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posted on 2006-07-04, 00:00 authored by Anand Bala Subramaniam, Cecile Mejean, Manouk Abkarian, Howard A. StoneWe report the behavior of particle-stabilized bubbles (armored bubbles) when exposed to various classes and
concentrations of surfactants. The bubbles are nonspherical, which is a signature of the jamming of the particles on
the interface, and are stable to dissolution prior to the addition of surfactant. Armored bubbles exposed to surfactants,
dissolve, and exhibit distinct morphological, microstructural, and lifetime changes, which correlate with the concentration
of surfactant employed. For low concentrations of surfactant, an armored bubble remains nonspherical while dissolving,
whereas for concentrations close to and above the surfactant cmc a bubble reverts to a spherical shape before dissolving.
We propose a microstructural interpretation, supported by our experimental observations of particle dynamics on the
bubble interface, that recognizes the role of interfacial jamming and stresses in particle-stabilization and surfactant-mediated destabilization of armored bubbles.