Non-aqueous foams: Current understanding on the formation and stability mechanisms

Anne-Laure Fameau (1) , Arnaud Saint-Jalmes (2)

1 BIA - Unité de recherche sur les Biopolymères, Interactions Assemblages
2 IPR - Institut de Physique de Rennes

Themost common types of liquid foams are aqueous ones, and correspond to gas bubbles dispersed in an aqueousliquid phase. Non-aqueous foams are also composed of gas bubbles, but dispersed in a non-aqueous solvent. In theliterature, articles on such non-aqueous foams are scarce; however, the study of these foams has recently emerged,especially because of their potential use as low calories food products and of their increasing importance in variousother industries (such as, for instance, the petroleum industry).Non-aqueous foams can be based on three differentfoam stabilizers categories: specialty surfactants, solid particles and crystalline particles. In this review, we onlyfocus on recent advances explaining how solid and crystalline particles can lead to the formation of non-aqueousfoams, and stabilize them. In fact, as discussed here, the foaming is both driven by the physical properties of theliquid phase and by the interactions between the foam stabilizer and this liquid phase. Therefore, for a given stabilizer,different foaming and stability behavior can be found when the solvent is varied. This is different fromaqueoussystems forwhich the foaming properties are only set by the foam stabilizer.We also highlight how these nonaqueousfoams systems can easily become responsive to temperature changes or by the application of light.

Keywords: oleogel; Non-aqueous Foam; solid particle; crystalline particle; contact angle; Foams; organogel

Domains: Physics [physics]; Condensed Matter [cond-mat]; Soft Condensed Matter [cond-mat.soft]

Anne-Laure Fameau, Arnaud Saint-Jalmes. Non-aqueous foams: Current understanding on the formation and stability mechanisms. Advances in Colloid and Interface Science, 2017, 247, pp.454 - 464. ⟨10.1016/j.cis.2017.02.007⟩. ⟨hal-01489745⟩