Controlling the lifetime of antibubbles.

An antibubble is a liquid droplet wrapped by a thin layer of gas, inside a bulk liquid usually of the same composition. The lifetime of an antibubble is governed by the drainage of the gas between the two liquid-gas interfaces populated by surfactants. Depending on the relative magnitude of surface viscosity and elastic moduli, which directly depend on or are determined by the nature of surfactants, the lifetime of an antibubble may vary a lot, from few seconds to few minutes. While such a difference can be predicted with models that include the role of interfacial properties, they were not observed experimentally in previous studies, due to important sources of dispersion. In this review, the main sources of dispersion are identified, such as (i) the initial amount of gas embedded in the antibubble, (ii) the level of saturation of gas in the bulk liquid, (iii) the presence of dust particles (<0.5 μm) in the gas, and (iv) three-dimensional flow effects. By accounting for these various effects, we obtain a coherent view on the lifetime of an antibubble, as a function of its radius and the surface rheology, with excellent consistency between experiments and modeling. Results thus demonstrate that controlling the size and lifetime of antibubbles is achievable. Unlabelled Image • Surface elasticity plays a dominant role in antibubble lifetime for small surfactant molecules; • Above a threshold, the lifetime is almost independent on the bulk concentration of surfactants; • Accounting precisely for gas dissolution in the liquid is crucial to obtain qualitative agreement with modeling. • The antibubble lifetime increases with the radius; • In controlled conditions, the antibubble collapse is shown to be a deterministic process; [ABSTRACT FROM AUTHOR]