Poly(N-vinyl carbazole)-TiO2 composite coating for protection of steel

Abstract

In this study, poly(N-vinyl carbazole)-TiO2 composite coatings (PNVC-TiO2) were electrochemically synthesized on the surface of 304 stainless steel (304-SS) using cyclic voltammetry from N-vinyl carbazole, tetrabutylammonium perchlorate and TiO2 containing non-aqueous acetonitrile solution. PNVC films were synthesized in the presence of different amounts (0.05%, 0.10% and 0.15%) of TiO2 and the optimum TiO2 amount was determined by comparison of potentiodynamic polarization curves of the stainless steel electrodes coated with these PNVC-TiO2 films. The synthesized PNVC-TiO2 films were characterized by ATR-FTIR and SEM investigations. Corrosion performances of PNVC-TiO2 coated stainless steel electrodes (SS/PNVC-TiO2) were investigated by Eocp-time curves, potentiodynamic polarization (PP) and electrochemical impedance spectroscopy (EIS) in 1 M H2SO4 corrosive test solution and compared with the data of SS-PNVC electrode. It has been found that the PNVC-TiO2 coating exhibited better protection performance than the PNVC coating and provides 97% protection efficiency against corrosion of 304-SS in a highly acidic corrosive environment.