Recent patents and industrial applications
Résumé
In this chapter, we will show how it is possible to modify the properties of material surfaces, thanks to the chemistry of aromatic diazonium salts applied to their functionalization. Overall, it is sufficient to play with the fragility of the C–N bond between the aromatic and the diazonium (–N2+ ) group. This bond breaks during a reduction reaction and leads to the formation of an extremely reactive aryl radical, which can react with a surface and form a covalently grafted coating by successive additions or initiate a radical polymerization reaction. This diazonium salt chemistry is simple, inexpensive, works in water and does not require energy input. It can be adapted to many substrates and is thus particularly suitable for industrial developments. We will see through the three following examples how to take advantage of these reactions to confer new properties to the surface of materials as varied as those encountered to biocompatibilize surgical implants (example 1), to make a robust optical sensor (example 2) or to treat light alloys for aeronautics (example 3).