Chemical interaction at copper/polyaniline interfaces

The chemical interaction between copper and the emeraldine salt of polyanil ine as deposited from a commercially produced dispersion has been investiga ted using x-ray photoelectron spectroscopy. On clean copper foil in vacuum the green conductive form remains stable, but upon exposure to air it is tr ansferred within 20 s to the blue non-conductive emeraldine base form and a t the same time Cu gets oxidized to Cu(I). Upon prolonged exposure to air a lso Cu(II) oxide formation is observed. Copper deposited onto the emeraldin e salt of polyaniline does not chemically change the polyaniline and due to the weak metal/polymer interaction initially small copper islands are form ed on the polyaniline which grow in size upon further copper deposition.