Expérimental
Fibrous media are ubiquitous in natural and engineered systems, due to their versatility, flexibility and functionality. Nonwovens (i.e. entangled fibrous networks), and especially natural fibre -based materials such as paper or flax mats, are heavily used for a variety of applications, and could be largely developed as a sustainable alternative for fossil-based plastics. The first limitation of their widespread use is their response to humidity, wetting or drying, which is unavoidable in many applications, and is a key step of their manufacturing processes. When a textile is placed in contact with a liquid, the liquid can spontaneously wick in between or inside the fibres; the liquid advances in the pores owing to a reduction of pressure at a curved front meniscus, or within the fibre through swelling. The goal of this internship/thesis is to characterize the imbibition dynamics using model systems, from pore-scale models of a few fibres to lab-produced model fibrous sheets, but also with large scale industrially produced nonwovens. We will also study the effect of swelling of individual fibres on the imbibition dynamics. Furthermore, the swelling can lead to large scale deformation that strongly depend on the orientation and arrangements of the fibers, which we can study with model systems.