Abstract
The aim of this thesis is to develop silica-based hybrid materials for selective extraction of Uranium from acidic and highly complexing media, such as ore leaching solutions or effluents generated in manufacturing plants of nuclear fuel cycle.The research project has several axes:• Study of the performance of different organic ligands (with nitrogen and phosphorus) for the extraction of uranium on solid.• Study of the influence of the link between the material and the ligand on the Uranium extraction performance.• Influence of the functionalization method (adsorption, grafting) and the adsorption surface on uranium extraction performances and mechanisms (EXAFS study)• Development of a method for the synthesis of silica-based hybrid materials with template effect adapted to the Uranium ores dissolution media.In each of the parts the approach goes from synthesis of the materials to evaluation of the materials performances for Uranium extraction, the solid characterization and the extraction mechanism comprehension.