Corrosion Protection Efficiency of Bilayer Porphyrin-Polyaniline Film Deposited on Carbon Steel

Summary Polyaniline (PANI) based composites and multilayers as well as porphyrin derivatives have been previously reported as efficient anti-corrosion coatings. In our studies, 5,10,15,20-tetra(4-methylphenyl)-21H,23H-porphyrin (TMP) was adsorbed on carbon steel surface before PANI electrodeposition, in order to improve the corrosion protection of PANI films on steel. The corrosion behavior of the TMP-PANI bilayer carbon steel modified electrodes was investigated in 0.1 M H2SO4 solution using electrochemical tehniques. It was found that TMP-PANI coatings can provide a good protection against carbon steel corrosion. The corrosion rate for the composite coated steel was significantly lower than that of the bare steel, and exhibited an inhibition efficiency of ∼80%.