Ion extraction applications of bilayer-structured hybrid silicas†
The self-assembly behaviour of amino-undecyl-triethoxysilane, which can be considered as an amphiphilic organosilane, has been used for the preparation of nanostructured materials. Due to the possibilities offered by this approach, lamellar hybrid materials bearing amine groups can be achieved. In this study, the reactive amino groups at the surface of the hybrid silica were modified for introducing ligands. For this purpose, various glycolamic acid groups have been introduced at the interface between two bilayers on the hybrid material obtained after condensation of silylated amines. The availability of the amino groups and the efficiency of the chemical immobilization of amic acid ligands onto the materials were followed by FTIR, NMR and TGA analysis, and the structural modifications induced by grafting were evaluated by SAXS experiments. The resulting materials exhibit a large number of amic acid groups. The adsorption capacities for rare earth elements were also investigated.