Universal inhibitors for lightweight alloys protection – UnILAP

In the transport field, structural lightening has become a major challenge in order to reduce greenhouse gas emissions and fight global warming and its ecological, economic and societal consequences. Light alloys (aluminum alloys) are commonly used as structural materials. Their corrosion resistance is mainly ensured by treatments based on hexavalent chromium, a toxic compound whose use is regulated until it is banned in 2024. It is therefore becoming urgent to develop alternative solutions.
The aim of this project is to develop a new family of corrosion inhibitors ensuring a high level of protection for a a wide range of aerospace alloys. To achieve this, we intend to rely on a new surface chemical engineering approach based on carbene chemistry and designed to respond to three major requirements: i) strong anchoring with the various alloys, ii) multi-functionalization of the ligand and iii) a green process. Since the 1990s, NHCs (for N-heterocyclic carbenes) have been attracting a great deal of attention in the field of materials, thanks to the robustness of the carbon-metal bond and their great modularity. Their use could be a promising, as yet unexploited, way to improve the durability of metallic materials. Alloy protection will be ensured by two combined effects: i) a specific action of the functional groups of the NHCs and ii) the formation of a three-dimensional layer obtained from the grafted NHCs in order to limit the diffusion of aggressive species at the interface.
This multidisciplinary project will focus on 3 areas: i) the synthesis and functionalization of NHCs, ii) the optimization of grafting and the growth of the three-dimensional layer and iii) the characterization of the systems and their reactivity