Abstract

Elastic interactions between neighboring bubbles in a foam are of fundamental importance for the rheological behavior and osmotic pressure of this material (1,2). In many recent simulations these interactions have been modeled by a potential, depending on the distance between neighboring bubble centers. Previous surface evolver studies and experiments strongly suggest that this potential is anharmonic, depending on local packing topology (2,3). In contrast, a recent confocal microscopy study of emulsions concludes that the potential should to a good approximation be harmonic (4). We compare new 3D Surface Evolver simulations of wet foams to these various previous results and discuss to what extent bubble interactions are accurately represented in terms of a potential. We also discuss on this basis how osmotic pressure and capillary pressure in foams scale with liquid fraction in the vicinity of the jamming transition.

(1) M. Le Merrer, S. Cohen-Addad, R. Hohler, PRL 2012 . Cohen-Addad, Hohler, Pitois, Annual Review of Fluid Mechanics 2013. (2) A. Maestro, W. Drenckhan, E. Rio, R. Hohler, Soft Matter, 2013. Hohler,Cheung Sang, Lorenceau, Cohen-Addad, Langmuir 2008 (3) Mason et al PRE 1997 (4) Jorjadze, Pontani, Brujic PRL 2013