Corrosion inhibition of mild steel using naphthalene disulfonic acid

The corrosion inhibition of mild steel is the subject of tremendous technological importance due to the increased industrial applications of this material. This paper reports the results of mass loss and potentiodynamic polarization measurements on the corrosion inhibition of mild steel in 0.5 M H2SO4 in the temperature range 30–60 °C using sodium naphthalene disulphonic acid (NDSA) as an inhibitor. The inhibition efficiency increased with the increase in concentration of NDSA till a critical value which is independent on temperature. The adsorption of inhibitor at 30 °C followed Flory–Huggins adsorption isotherm and the value of standard free energy of adsorption suggests that it is chemisorption.