Physics of Foamed Suspensions_Drainage

Foam-based materials are promising micro-structured materials with interesting thermal and acoustical properties. The control of the material morphology requires counteracting all the destabilizing mechanisms during their production, starting with the drainage process, which remains to be understood in the case of the complex fluids that are commonly used to be foamed. During the PhD thesis of Benjamin Haffner (2012-2015) we performed measurements for the drainage velocity of aqueous foams made with granular suspensions of hydrophilic monodisperse particles and we showed that the drainage behavior is entirely controlled by two parameters: the volume fraction of particles in the suspension (φp) and the confinement parameter (λ), that compares the particle size to the size of passage through constrictions in the foam network. We reported data over wide ranges for those two parameters and we identified all the regimes and transitions occurring in the φp-λ diagram. In particular, we highlighted a transition which refers to the included / excluded configuration of the particles with respect to the foam network, and makes the drainage velocity evolve from its minimal value (fully included particles) to its maximal one (fully excluded particles). We also determined the conditions (φp,λ) leading to the arrest of the drainage process.

Related Papers:

– The drainage of foamy granular suspensions, B. Haffner, Y. Khidas, O. Pitois, Journal of colloid and interface science (2015) 458, 200-208

– Foam clogging, F. Rouyer, B. Haffner, N. Louvet, Y. Khidas, O. Pitois, Soft Matter (2014) 10, 6990-6998

– Capture-induced transition in foamy suspensions, Y. Khidas, B. Haffner, O. Pitois, Soft Matter (2014) 10, 4137-4141

– Flow and jamming of granular suspensions in foams, B. Haffner, Y. Khidas, O. Pitois, Soft Matter (2014) 10, 3277-3283