Exploiting elastocapillarity in the mechanical self-assembly of drops and bubbles
Wiebke DRENCKHAN et Aurélie HOURLIER-FARGETTE
CNRS/Université de Strasbourg
The mechanical assembly of bubbles or drops in a liquid carrier matrix generates foams or high internal phase emulsions. With increasing packing density, their morphology ranges from neatly packed spherical objects at jamming (A) to space-filling polyhedra (B). Since the geometrical and topological features of the resulting morphologies are dictated by minimisation of interfacial area (i.e. by capillarity), they obey fairly strict rules. In polyhedral packings, for example, these are called Plateau’s rules: three films meet at 120° in “Plateau borders” and four Plateau borders meet in vertices of tetrahedral symmetry. Such tight constraints on foam/emulsion morphology put equally tight constraints on their physical properties, in particular, when they are used as templates for cellular materials. In the search for a wider range of morphologies it is therefore of great interest to establish mechanisms which allow to interfere with the mechanical self-assembly process in a controlled manner. A powerful tool arises from working with elastic interfaces (C) or elastic intruders (D), whose deformation adds additional elastic contributions to the system’s overall energy – and hence to the architectures obtained in mechanical equilibrium. We will provide a short state-of-the-art of the subject, illustrated by examples of emulsions whose drops are covered with elastic skins and foams mixed with elastic fibres/ribbons.
[1] W. Drenckhan & S. Hutzler, Structure and energy of liquid foams, Adv. Colloid Interface Sci., 224, 1–16 (2015).
[2] A. Giustiniani, S. Weis, C. Poulard, P. H. Kamm, F. Garcia-Moreno, M. Schröter & W. Drenckhan, Skinny emulsions take on granular matter, Soft Matter, 4, 7310–7323 (2018).
[3] M. Jouanlanne, A. Egelé, D. Favier, W. Drenckhan, J. Farago & A. Hourlier-Fargette, (2022). Elastocapillary deformation of thin elastic ribbons in 2D foam columns, Soft Matter (2022).
IMAGES
Vague en étoile (plus de détails...)
CONFÉRENCES
New Challenges in Turbulence Research VII, École de Physique des Houches, 10 Février 2025
New Challenges in Turbulence Research VII, École de Physique des Houches, 10 Février 2025
New Challenges in Turbulence Research VII, École de Physique des Houches, 10 Février 2025