Offer DescriptionOne of the key steps in material recycling is crushing or grinding them into finer elements, namely granular materials or powder for sorting and reuse. This applies to glass, which is melted (calcined) into production lines, plastics, aggregates from deconstruction, composite materials, or rubber waste. Since the crushing/grinding stage is already energy-intensive, there is an interest in recycling the crushed elements as directly as possible. In many cases, simple shaping using a binder, and potential post-treatment of the peripheral surfaces, could produce blocks for urban furniture and construction. One of the major practical difficulties in implementing these granular assemblies, whether recycled or not, is the dispersion of the binder at the contacts between the grains to produce binder bridges that will ensure the cohesion of the whole. This generally requires coating the grains with a thin layer of binder beforehand and then assembling and compacting the whole. The difficulty lies in the uniformity of the binder layer that needs to be deposited on the surface of all grains: this requires a lot of mixing, blending, and manipulation of the grains, especially if one aims to minimize the amount of binder. Another approach is to completely fill the porosity of the grain stacks with the binder, then desaturate the porosity by pushing air into it. In addition to being very binder-intensive, such an approach is known to pose problems of desaturation front instability, which can lead to a very uneven distribution of the liquid (binder).The starting point of this project is that a complex liquid foam (liquid foam loaded with a binding component) represents a top choice low-carbon binder precursor that can easily fill the voids offered by packings made of such grains, to shape the whole and impart significant mechanical strength to it. There is an expectation to greatly reduce the amount of binder required, thanks to the proportion of air (70-90%) introduced with the binder, while avoiding the instability problems mentioned earlier, due to the rheological properties of liquid foams.The manufacturing steps of controlled liquid foam (in terms of bubble size and air fraction) and loading this foam with various suspensions (such as soil or cement slurries, for example) are well mastered in the laboratory. In this project, the aim will be to fill the porosity of grain packings with such foams, study the distribution of the slurry in the porosity (X-ray tomography), and measure the mechanical strength of these assemblies after drying. This mechanical characterization will be performed both at the scale of the packing and at the scale of two grains bonded by solid foam.RequirementsResearch Field Physics Education Level Master Degree or equivalentSkills/QualificationsThe candidate will need to demonstrate knowledge in materials science. An initial background in physics or mechanics would be advantageous. A strong inclination towards experimentation is necessary, but an affinity for image processing (python, Fiji, matlab) would also be a plus.Languages ENGLISH Level GoodResearch Field Physics » Chemical physicsAdditional InformationWork Location(s)Number of offers available 1 Company/Institute Université Gustave Eiffel Country France GeofieldWhere to apply E-mailolivier.pitois@univ-eiffel.frContact State/ProvinceFRANCE CityChamps-sur-Marne WebsiteStreetBoulevard Newton Postal Code77420 E-Mailolivier.pitois@univ-eiffel.frSTATUS: EXPIRED