Structure and energy of liquid foams

Abstract

a b s t r a c t a r t i c l e i n f oWe present an overview of recent advances in the understanding of foam structure and energy and their dependence on liquid volume fraction. We consider liquid foams in equilibrium for which the relevant energy is surface energy. Measurements of osmotic pressure can be used to determine this as a function of liquid fraction in good agreement with results from computer simulations. This approach is particularly useful in the description of foams with high liquid content, so-called wet foams. For such foams X-ray tomography proves to be an important technique in analysing order and disorder. Much of the discussion in this article is also relevant to bi-liquid foams, i.e. emulsions, and to solid foams, provided that the solidification preserves the structure of the initially liquid foam template.

Statistics and topological changes in 2D foam from the dry to the wet limit

“…For these we can benefit from both straightforward models and reliable F o r P e e r R e v i e w O n l y numerical methods. More recently, attention has moved to the case of wet foams [2,3], which pose new challenges.…”

The role of biofoam in shielding spittlebug nymphs (Insecta, Hemiptera, Cercopidae) against bright light

“…Inferences based on the bulk distributions of the surface bubbles have been shown to allow reliable estimates of average foam bubble sizes (Cheng & Lemlich, 1983;Drenckhan & Hutzler, 2015). After 3 days, the foams produced by nymphs of the various instars were photographed together with a scale using a digital camera (Canon EOS 60D) coupled with a macro photo lens (Canon MP-E 65 mm).…”

Analytical Geometrical Model of Open Cell Foams with Detailed Description of Strut‐Node Intersection

“…A new geometrical model of open cell foams is herein proposed, which is fully derived analytically starting from the following hypotheses: adoption of the Kelvin cell as the foam unit cell, approximated with a tetrakaidecahedron in the mathematical derivation; four struts converging in each node according to Plateau rules forming an angle γ , expressed in Eq. struts with circular or triangular cross section, converging in nodes with truncated sphere and tetrahedral geometry, respectively; parabolic profile of the lateral surface of the strut; C 1 continuity of the profile at the strut‐node intersection. …”