Photochemical Grafting and Patterning of Metallic Surfaces by Organic Layers Derived from Acetonitrile

Metallic substrates are modified by a polymeric layer obtained under photochemical irradiation of acetonitrile. The reaction involves a photogenerated radical and leads to the covalent bonding of the organic layer to the metal. Different characterization techniques allow to unravel the structure of the layer: Substrate-CH₂-CH-(NH₂)[-CH₂-CH-(NH₂)-]_n-[CH₂-C(O)]_m. A mechanism is discussed that accounts for the formation of the layer. The method is quite easy to implement, it only necessitates a UV lamp and a very common solvent. Photografting is well suited to pattern surfaces with polymeric layers by irradiation through a mask, and finally, the patterning of copper at the micrometer scale is described as a proof of concept.