Electrochemical Study and Spectroscopic Methods used for Self Assembling Nanofilm Formed by Polyacrylic Acid on Mild Steel in Aqueous Environment

Inhibition of mild steel corrosion in 60 ppm chloride medium by Polyacrylic acid (PAA), Trisodium citrate (TSC) and Zn²⁺ ions was investigated by weight loss measurement, potentiodynamic polarization, electrochemical impedance studies (EIS), Fourier transform infrared spectroscopy (FT-IR), Scanning electron spectroscopy (SEM), Energy dispersive X-Ray spectroscopy (EDS) and Atomic force microscopy (AFM). The results indicated that the TSC acts as an optimum in the inhibition efficiency (95%) is observed for a concentration close to 100 ppm, addition to increase in TSC concentration decrease the inhibition efficiency. Potentiodynamic polarization studies inferred that this mixture functions as a cathodic inhibitor. EIS studies of the metal/solution interface indicated that the surface film is highly protective against the corrosion of mild steel. Surface characterization techniques (FT-IR, SEM, EDS and AFM) are also used to ascertain the nature of the protective film. The mechanical aspect of corrosion inhibition is proposed.