Coarsening transitions of wet liquid foams under microgravity conditions

Marina Pasquet; Nicolo Galvani; Alice Requier; Sylvie Cohen-Addad; Reinhard Höhler; Olivier Pitois; Emmanuelle Rio; Anniina Salonen; Dominique Langevin

arXiv · 2304.11206

Coarsening transitions of wet liquid foams under microgravity conditions

Marina Pasquet·Nicolo Galvani·Alice Requier·Sylvie Cohen-Addad·Reinhard Höhler·Olivier Pitois·Emmanuelle Rio·Anniina Salonen·Dominique Langevin

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Abstract

We report foam coarsening studies which were performed in the International Space Station (ISS) to suppress drainage due to gravity. Foams and bubbly liquids with controlled liquid fractions $\phi$ between 15 and 50\% were investigated to study the transition between bubble growth laws previously reported near the dry limit $\phi \rightarrow 0$ and the dilute limit $\phi \rightarrow 1$ (Ostwald ripening). We determined the coarsening rates; for the driest foams and the bubbly liquids, they are in close agreement with theoretical predictions. We observe a sharp cross-over between the respective laws at a critical value $\phi^*$. At liquid fractions beyond this transition, neighboring bubbles are no longer all in contact, like at a jamming transition. Remarkably $\phi^*$ is significantly larger than the random close packing volume fraction of the bubbles $\phi_{\text{rcp}}$ which was determined independently. We attribute the differences between $\phi^*$ and $\phi_{\text{rcp}}$ to a weakly adhesive bubble interaction that we have studied in complementary ground-based experiments.

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Marina Pasquet, Nicolo Galvani, Alice Requier, Sylvie Cohen-Addad, Reinhard Höhler, Olivier Pitois, Emmanuelle Rio, Anniina Salonen, Dominique Langevin. 2023-04-21. Coarsening transitions of wet liquid foams under microgravity conditions. https://arxiv.org/abs/2304.11206

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