Antibubbles are millimetric drops encapsulated in a spherical thin film of gas, within a liquid medium. The hydrostatic pressure within the thin film is higher at the bottom of the antibubbles than at the top, which leads the upwards drainage of the gas. This process results in a thinner film at the bottom, that gets more fragile and eventually bursts. The ephemeral nature of antibubbles constitutes a challenge towards their use in potential applications such as drug delivery or microreactors. I will present two strategies addressing this challenge, the study of which led to results more general than antibubbles stabilization. The first one consists in replenishing the thin film through the vaporisation of the liquid core in a heat-transfer-limited process, that we call ‘thermal antibubble’. It helps to understand the important contribution of droplet thermalization on the early stage of the Leidenfrost phenomenon. The second one deals with the dissolved atmospheric gasses transfer from the surrounding bulk to the gas shell, that counteracts drainage. I will present the so-called antibubble column used to quantify this mass transfer and discuss its advantages.
Accès Petit amphi du bâtiment Pascal (530); retransmission zoom