Effect of Zn²⁺ doping on corrosion resistance of polyaniline film prepared by electrochemical synthesis

In order to improve corrosion resistance of polyaniline (PANI) film, in the system of aniline-sulfuric acid electrolytic fluid, the electrochemical constant current method was adopted to prepare PANI film on surface of stainless steel. The effect of Zn²⁺ doping on corrosion resistance of PANI film prepared by electrochemical synthesis was studied using electrochemical measurement technology, SEM and XRD. Results show that Zn²⁺ doping can change the microstructure morphology of PANI film from irregular flake into fibrous. The alternating-current impedance of PANI film increases markedly after doping modification, the corrosion potential moves towards the positive direction, and the corrosion current decreases. The 10wt% HCl drop corrosion time of the PANI film with doped Zn²⁺ is 320 s, and no rust appears after neutral salt mist experiment for 48 h.