Nanoparticles networking using ionic linkers

The 2D or 3D linking of metal or metal oxide nanoparticles is still a challenge, as well as research concerning the association of ionic species with nanoparticles. The originality of this fundamental chemistry proposal lies in the combination of nanoparticles organization and concomitantly the introduction of ionic species. Furthermore, it is a new and original method for letting modified nanoparticles react with one another. This will result in covalently linking nanoparticles by means of an ionic linker. The cationic groups will be part of the network formed by linked nanoparticles, while the anion is still free in the network and should induce ionic conductivity. For this project we will focus on the synthesis of the new hybrid materials and on the evaluation of the ionic conductivity and ion exchange properties. With this aim we propose the investigation of the scope of the new preparative approach with regard to modifying the nature of the ionic bridge as well as the nature and size of the nanoparticles. These modifications will be correlated with the ionic conductivity and ion exchange properties of the materials. The innovation of this proposal concerns the proposed method, which is very promising and should be very efficient and general.

Nanoparticle assemblies are very challenging and highly promising structures for material science. In this project we have developed an original and controllable synthesis pathway to prepare nanoparticle assemblies. The assembling process is based on the reaction of the ligands attached to the surface of the nanoparticles. This reaction leads to the formation of inter- particle imidazolium species. The presence of the imidazolium species delivered tailorability to the material. Indeed the imidazolium can easily be modified, as well as the counter anion can be exchanged. Such modifications are strongly influencing the affinity of the material and its physico-chemical properties. The newly obtained materials were fully characterized. For the characterizations solid-state analyses were carried out: as energy dispersive X-ray analysis to get access to the composition of the material; small angle X-ray scattering to collect structural information on the ordering of the building blocks; thermal analysis which indicated a material with a high thermal stability, up to 300C under air; and luminescence spectroscopy. The excellent results obtained from the analyses of the materials have conducted to deep investigation first, of the luminescence properties and second, of the catalytic activity of the materials.