Abstract:

Effects of substrate materials on the properties of nanofibrous polyaniline(PANI) film prepared by the pulse galvanostatic method(PGM) were investigated. The chronopotentiograms of aniline polymerization in 0.3 mol/L aniline+1 mol/L HNO₃ aqueous solution showed that the anodic potential on Pt and Ru electrodes rised to 880 and 850 mV quickly when the mean current density was 1.0 mA/cm2 . The potential turned to 750 mV after about 40 s and kept constant until the experiment was over. When the aniline polymerization occurred on stainless steel(SS) and Al electrodes, the anodic potential climbed to 1100 and 1700 mV respectively, and after about 55 and 250 s it turned to 750 mV. The scanning electron microscopic images demonstrated that the PANI films on Pt, Ru, SS and Al prepared by PGM all exhibited a similar fibrous morphology with a diameter of 80-100 nm. Therefore, it can be considered that the PGM polymerization of aniline on different substrate materials was markedly distinct when the surface of electrode was not covered by PANI completely. The cyclic voltammograms and electrochemical impedance spectroscopy results showed that PANI films on various substrates presented different electrochemical reactivities in an aqueous aniline free solution of 1 mol/L HNO₃.

Key words: Polyaniline; Substrate material; Pulse galvanostatic method; Electrochemical behavior