Capillary imbibition in open-cell monodisperse foams
Résumé
Hypothesis: Although capillary imbibition of solid foams is involved in many industrial applications, general
theory for capillary imbibition has never been proved to apply for this specific class of porous materials.
Experiments: In order to compare accurately experiment and theory we produce solid foam samples
with monodisperse pore size distributions and tunable pore volume fraction, and we measure their permeability
(Darcy), their capillary pressure and their imbibition rate.
Findings: Our findings reveal that the imbibition velocity is qualitatively compatible with the
Washburn theory but it is one order of magnitude smaller than the predicted value. This deviation is
attributed to the excess time spent by the liquid-gas interface through connections between pores, for
which an empirical expression is provided as a function of pore size and solid volume fraction. Our results
provide the first step to understand deeply the imbibition process in foams and to predict imbibition
rates for various foamed materials.