Fe-based surface activator for electroless nickel deposition on polyester: Application to electromagnetic shielding

The activation of the polyester (PET) by the solution of ferrous compound was examined as a palladium-free activation process. The principle of the process is based on the adsorption of Fe2 + on the substrate surface, reduction of Fe2 + into elementary substance Fe0, which is served as the catalyst for electroless plating. The Ni/PET composite can be obtained in three steps, namely: (i) the grafting of amino groups onto PET surface, (ii) the iron Fe0 seeding of the PET surface, and (iii) the nickel metallization using electroless plating bath. XPS, XRD, and AFM were used to characterize each step of the process. Adhesion of the nickel coating on PET was evaluated by a Scotch® tape test. Corrosive resistance of the Ni/PET composite was examined by a salty solution. The electromagnetic shielding effectiveness of the Ni/PET composite was more than 50 dB at frequency ranging from 100 to 1000 MHz. Comparing Fe2 + with Ni2 + as the metallic resource of the catalyst for electroless plating via the same process: the former resulting in a quicker nickel deposition rate and better nickel adhesion performance.