Inhibition Performance of Self-assembled Polydopamine Film on the Surface of 316L Stainless Steel

Polydopamine film was fabricated by dipping 316L stainless steel(316L SS) substrate into an aqueous alkaline dopamine solution, and the adsorption behavior of the film and its corrosion inhibition performance for 316L SS in 0.9% NaCl solution were studied by potentiodynamic scanning, electrochemical impedance spectroscopy(EIS), attenuated total reflectance fourier transform infrared spectrum (ART-FTIR) and scanning electron microscopy (SEM). The results showed that the polydopamine membranes formed by oxidation and polymerization reaction of dopamine molecules were adsorbed onto the surface of 316L SS by the combination between oxygen and metal atoms. The assembling in low dopamine concentration acceleratee the corrosion of 316L SS,but could inhibit the corrosion in the concentration above 10 g/L. And the best corrosion inhibition performance was obtained under the conditions of 20 g/L concentration and 24h assembling time.