Enhanced Anti-corrosive Properties of Electrosynthesized Polyaniline/zeolite Nanocomposite Coatings on Steel

Abstract

The preparation of polyaniline/zeolite nanocomposite coating on 304 stainless steel (304 SS) surface has studied via the galvanostatic method. The electro-generated coating was characterized by Fourier transform infrared spectroscopy (FT-IR), UV-visible absorption spectroscopy, X-ray diffraction (XRD) patterns and scanning electron microscopy (SEM). The anticorrosion property of polyaniline/zeolite nanocomposite coating was explored in 0.5 M hydrochloric acid solution by Tafel polarization method and electrochemical impedance spectroscopy (EIS). The effect of variable parameters such as the applied current density and deposition time on the corrosion protection of the electro-generated coatings was also considered. The corrosion rate of coated-304 SS was releazied about 36 times lower than bare 304 SS. Potential of corrosion also changed from -0.411 V to -0.279 V versus Ag/AgCl for un-coated and coated-304 SS electrodes, respectively. Electrochemical measurements indicate that polyaniline/zeolite nanocomposite coated on 304 SS has remarkable inhibitive properties with protection effectiveness of ~97% at 2.5 mA cm-2 current density used on 304 SS in acidic medium. The outcomes of this research obviously find out that the polyaniline/zeolite nanocomposite has an outstanding possible to defend 304 SS against corrosion in an acid environment.

Keywords

• coating
• corrosion
• electrosynthesis
• polyaniline/zeolite nanocomposite
• 304 stainless steel