Surface Modification and Electrochemical Metallization of Advanced Polymers for Energy Application

For some demanding applications the peculiar properties of polymers, as lightweight, flexibility and chemical resistance, need to be enriched with additional characteristics that are traditionally associated with metals, such as thermal and electrical conductivity, barrier to fluids, high hardness, tribological resistance and reflectivity. Applications, requiring this coupling of different properties, include flexible electronics, barrier layers and alternative energy^1–3. In these applications a thin layer of metal, on top of the polymeric substrate, is sufficient to assure the required properties. The main issue of these composites is the adhesion between the two materials and is related to the low surface energy of polymers⁴. To overcome adhesion issues between the polymeric and metallic layer, several dry and wet processes have been proposed^5–7 that imply the utilization of expensive tools or aggressive chemicals. We propose an alternative method to perform metallization of partially fluorinated polymers based on a two-step process: a) chemical functionalization of the substrate surface, for increased adhesion and b) activation and electroless metallization with Cu or Ni-P. After this process we have a continuous, adherent and conductive metallic layer that allows for surface finishing by electrodeposition. We produced continuous metallic thin layers of Cu and Ni-P on different partially fluorinated polymers achieving a 5B adhesion in the ASTM D3359 cross cut test. Considering the application of metallized polymeric films for solar thermodynamic, the electrodeposition of Al from air and water stable ionic liquids is being investigated.

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