Anticorrosive Performance of Nano ZnS Reinforced Polyaniline Coatings on Q235 Carbon Steel

Abstract

Nano-ZnS was prepared by hydrothermal method and polyaniline was prepared by chem- ical oxidation respectively, which then were blended to prepare a series composite materials of polyaniline modified by nano-ZnS. Finally the relevant composite coatings were applied on Q235 carbon steel. The acquired composite materials and coatings were characterized by scanning elec- tron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The electrochemical corrosion performance of the compos- ite coatings in 3.5% (mass fraction) NaCl solution was investigated by potentiodynamic polariza- tion and electrochemical impedance. The results showed that the nano-ZnS was uniformly dis- persed in the polyaniline matrix and therewith the anticorrosive performance of the coatings was improved significantly. Among others the coating with 50% (mass fraction) ZnS exhibited the best anticorrosive performance with a protection efficiency 99.9% after immersion in 3.5%NaCl solu- tion for 7 d. Besides, after immersion for 30 d, the coating surface morphology changed obserious-