PLASMA-POLYMERIZED POLYANILINE FILMS - SYNTHESIS AND CHARACTERIZATION

The radio-frequency plasma polymerization technique was used to polyme rize aniline onto polymer substrates including perfluorinated ethylene propylene copolymer. The plasma-polyaniline films were characterized by ultraviolet/visible absorption spectroscopy, Fourier transform infr ared spectroscopy, electron spin resonance, X-ray photoelectron spectr oscopy, scanning electron microscopy, and contact angle measurements. Preliminary conductivity measurements were also carried out. It was de monstrated that the chemical and physical characteristics of the plasm a-polymerized polyaniline films changed significantly with discharge c onditions, indicating the possibility for tailoring the structure and properties of the polyaniline films by optimizing the discharge condit ions. In particular, the contents of quinoid sequences and aliphatic c rosslinking moieties were found to increase with increasing power inpu t and/or discharge duration. By contrast, the number of free radicals trapped in the polyaniline films and their mobility were shown to incr ease with decreasing the power input and/or discharge duration within the plasma conditions covered in this study. Furthermore, a correlatio n was found between surface hydrophilicity of the resultant plasma-pol yaniline films and the atomic ratio of C to N. (C) 1998 John Wiley & S ons, Inc.