Chemical Metallization of Insulating Polymeric Surfaces Through Simple Diazonium-Based Covalent Amination

Electroless plating or autocatalytic deposition on insulating polymeric substrates via surface amination is currently of potential interest since the grafted amine functionalities significantly decrease the total quantity of noble metal catalyst and offer good adhesion between the polymer substrate and the deposited films. Among various wet-chemical amination strategies available in the literature, diazonium-induced anchoring process appears to be very promising due to many advantages: one-step aqueous chemical process, provides covalent grafting of amine-terminated groups, carried out in open air and at room temperature. This work covers our recent studies on the grafting of aminophenyl and vinylpyridine groups through diazonium chemistry onto various polymers. We discuss the ability of these amine-terminated functionalities towards the chemisorption of acidic palladium chloride activators, which subsequently initiate autocatalytic deposition process. Our studied polymers functionalized with these palladium complexes perfectly suit the subsequent electroless nickel plating process. The covalently grafted amine groups provide excellent adhesion of the deposited nickel film on polymers. SEM, AFM, EDX and XPS techniques are used to characterize the electrolessly deposited metallic film.