Corrosion Protection of Mild Steel by Polyaniline/Tin-Doped Titania Nanocomposite

This study applied the template -free chemical oxidative polymerization method to synthesize polyaniline (PANI) and polyaniline/tin-doped titania (PANI/Sn-doped TiO 2 ) nanocomposite as corrosion inhibitors. FT-IR and XRD were utilized to characterize the chemical composition of the prepared samples. TEM and FESEM microscopy validated the presence of the PANI and that the Sn-doped TiO 2 nanoparticle were successfully incorporated into PANI to form the nanocomposite. The synthesized materials were mixed in the polyvinyl butyral (PVB) binder, coated onto mild steel substrates and exposed to 3.5 wt.% NaCl solution for 30 days. Altogether, three coating systems were tested, i.e., pure PVB, PVB + PANI and PVB + PANI/Sn-doped TiO 2. The corrosion parameters were measured via EIS and Tafel polarization techniques. Overall, the PANI/Sn-doped TiO 2 nanocomposite as a corrosion inhibitor effectively inhibited the corrosion of the mild steel, and its corrosion rate was 3.484 x 10 -7 mm/year.