Mission of the project
In this project we propose the combination of selective UO22+ binding chemistry with materials chemistry, to create materials with a large sorption capacity for uranium, and also a large selectivity towards uranium vs. various divalent and trivalent cations. These materials will be suitable for mining uranium directly from seawater or from a desalination plant and as sensors for the detection and determination of UO22+. The application is in the areas of environmental technology and sustainable development.
Objective 1
The synthesis of organic multi-metal and/or luminescent chelators for the selective binding and sensing of metal ions based on both the hard-soft properties and the geometric preference for the coordination sphere around each metal ion. The basic cores of the ligands, known from the literature, the bis-hydroxylamine triazine for the ligation of hard metal ions, have been used by us in the past for the binding of VIV/V, MoVI and UVI ions. This type of ligands is not toxic and has extraordinary stability and selectivity for UO22+ complexation compared to other hard metal ions that are present in the sea; the same donor atoms are proposed for the new ligands in this project. Except from the ligands exhibiting the bis-hydroxylamine triazine ligating group a new bis-hydroxylamine bis-triazine compound will be synthesized. This new ligating group is expected to be even stronger binder for hard metal ions than bis-hydroxylamine triazine.
Objective 2
Novel complexes of these ligands with UO22+ will be synthesized and their structural and the spectroscopic properties will be characterized. The formation stability of the complexes will be determined for the first time. In addition, the selectivity and sensitivity for the UO22+ binding based on luminescence of the complexes will be determined.
Objective 3
Novel functionalized derivatives containing these ligands as well as their complexes with the target metal ions will be synthesized, and subsequently characterized. Removal of the metal ion from the polymerized complexes will leave empty sites specifically allocated for the coordination to the same target metal ions, exhibiting optimized metal-binding selectivity. All of the materials chemistry involved is novel, as - to the best of our knowledge - these ligands have never been used before in polymerization processes or in grafting reactions.
Objective 4
State of the art techniques (Lederer-Manasse reaction, sol-gel) will be used for the first time in order to prepare nanostructured (nanofibers, nanoparticles) polymeric materials for the adsorption of uranyl from seawater and wastewater. The project will develop both organic polymers and inorganic mesoporous silicates. It is the first time that the same underlying complexation chemistry of UO22+ is used for the same application simultaneously on two different platforms, one organic and one inorganic.
