Anti-corrosion characteristics of electrodeposited self-doped polyaniline films on mild steel in low acidity

Abstract

Without the addition of inorganic acids, 2,5-Diaminobenzenesulfonic acid (DABSA) molecules form an acid environment, and are then electrochemically copolymerized with AN monomers to generate a self-doped polyaniline (SPAN) film on mild steel substrates. These SPAN deposition films are employed to test the protection efficiency for mild steel in a corrosion environment of HCl and NaCl, respectively. Electrochemical impedance spectroscopy (EIS) and polarization were used to determine the charge transfer resistance (Rct) and corrosion current (Icorr), respectively. The above two parameters Rct and Icorr are combined to evaluate the protection efficiency of SPAN film on mild steel. Experimental results show that the SPAN thin film with the AN/DABSA ratio of 8.8 has the optimal corrosion resistance in 1 M HCl and 1 M NaCl aqueous solutions, respectively.