CHARACTERIZATION OF POLYACRYLONITRILE FILMS GRAFTED ONTO NICKEL BY ELLIPSOMETRY, ATOMIC-FORCE MICROSCOPY AND X-RAY REFLECTIVITY

The thickness and roughness of polyacrylonitrile films electrografted on a nickel surface have been measured by ellipsometry atomic force mi croscopy and X-ray reflectivity. From combined ellipsometry and X-ray reflectivity measurements, accurate values for the refractive indices of polyacrylonitrile and nickel have been derived at a 6328-Angstrom w avelength. Dependence of the film thickness on the monomer concentrati on has been quantified for the first time. Furthermore, the thickness of the polyacrylonitrile (PAN) film is related to the nature of the so lvent, depending on whether it is a good solvent for PAN (dimethylform amide; DMF) or not (acetonitrile; ACN). (C) 1997 Elsevier Science S.A.