Smart Foams: Switching Reversibly between Ultrastable and Unstable Foams

Abstract

6 pagesInternational audienceUltrastable foams with an optimal foamability have been obtained using hydroxyl fatty acids tubes. The stabilization results from the adsorption of monomers at the air-water interface preventing coalescence and coarsening and from the presence of tubes in the Plateau borders limiting the drainage. Upon heating, tubes transit to micelles, which induces foam destabilization. Such foams are thus the first to have a temperature tunable stability

Responsive self-assemblies based on fatty acids

“…Recently, some studies have focused on the use of the structural transformations of self-assemblies based on fatty acids occurring at the mesoscopic level to finely control the physical properties at the macroscopic scale. Original macroscopic properties have been found, such as thermoresponsive foams and interfaces [4][5][6], which cannot be achieved by conventional low molecular weight synthetic surfactants.…”

“…Recently, responsive foams reacting to external stimuli and made from solutions containing self-assemblies based on fatty acids have been reported. These foams are based on the structural transitions occurring both in bulk and at the interface with temperature in a few seconds [5,56]. Thermoresponsive foams have been obtained from the 12-HSA tubes described previously.…”

“…Thermoresponsive foams have been obtained from the 12-HSA tubes described previously. Foams produced from these 12-HSA tubes solution are outstandingly stable over months and described as "ultra-stable" [5]. The origin of this stability comes from both the presence of tubes in the foam liquid channels and at the air/water interface, which prevent the foam destabilization by reducing drainage, coalescence and coarsening [5].…”

Effect of polyelectrolytes on (de)stability of liquid foam films

“…For instance "blocking of Plateau borders" was also used to switch the foam stability by using thermosensitive vesicles, which can change the shape. 46,47 In addition, networklike structure at the surface leads to higher surface elasticity which stabilizes the lm due to easier reduction of local uc-tuations. In addition, larger protein aggregates at the lm surface contribute stronger to electrostatic repulsion and therefore to lm stability than small aggregates.…”

Les acides gras hydroxylés : agro-tensioactifs aux propriétés moussantes originales

“…De façon surprenante, le volume de mousse ainsi que l'aspect de la mousse ne change pas pendant plus de 6 mois (figure 6). Ces mousses sont donc incroyablement stables, contrairement aux tensioactifs classiques dont la stabilite des mousses n'excede pas quelques heures (Fameau et al, 2011d). Ceci provient de la formation d'une monocouche dense et tres elastique de monomeres d'acides gras a l'interface air/eau, via des liaisons hydrogene entre les groupements hydroxyles des monomeres d'acide gras 12-hydroxystearique.…”