A NEXAFS Study of Thin Polyacrylonitrile Films Electrochemically Deposited on Ni: The Effect of the Film Thickness and Annealing Treatment

Polyacrylonitrile (PAN) thin films electrochemically deposited on Ni have been studied by near edge x-ray absorption fine structure, as a function of the film thickness and annealing treatment. For 20Å thick films, the polymer chains are oriented perpendicular to the surface with the C=N groups parallel to it. Below a few angstroms, no polymerization occurs but molecules are adsorbed perpendicular to the surface. Annealing at 300°C results in the loss of the majority part of the N content of the film in contrast with the admitted mechanism for bulk PAN.