Institut Charles Sadron Event

The aim of this thesis is to create new materials by modifying the geometry and topology of foams (shape, size and connection of bubbles) through the introduction of fibres. The first part of the thesis focuses on a model experiment enabling the quantification of the equilibrium forms of foam/elastic ribbon systems, with excellent agreement between theory and experiment, and highlighting the competition between elasticity and capillarity. The second part of the thesis develops the elaboration of solid foams from a liquid precursor, formed using a bubbling through nozzles. The fibres are then introduced into the foams in the liquid state, i.e., allowing the bubbles and fibres to organise themselves spontaneously before the solidification stage. Different formulations were studied, focusing on alginate hydrogel and polyurethane foams. Finally, the third part of the thesis analyses the impact of rigid and ordered fibres on the structural modification of foams. A characterisation protocol was developed using X-ray tomographic images. All this work shows that by selecting the foaming technique, the formulation of the foam constitutive material and the geometry of the fibres, it is possible to produce composite materials with unique structures, considerably modified by the inclusion of fibres and promising in terms of mechanical properties. Keywords: Foam, Alginate, Polyurethane, Elastocapillarity, Composite, X-ray tomography