Inhibitory properties of walnut shell extract for steel 20 in neutral and acidic environments

Keywords

eco-inhibitor, walnut shell, extract, low carbon steel, corrosion rate, protection degree, potential, surface tension.

Cite as

Korniy S. A., Slobodyan Z. V., Kupovych R. B., Mahlatyuk L. A., and Rizun Yu. Ya. Inhibitory properties of walnut shell extract for steel 20 in neutral and acidic environmentsм. Physicochemical Mechanics of Materials. 2026. 62(3), 5-12.

Abstract

The method of obtaining walnut shell extract was developed. Gravimetric and electrochemical methods of investigation established that the extract exhibited inhibitory properties of 20 steel in tap water, citric and hydrochloric acids. In the temperature range of 298–333 K, maximum corrosion protection is observed in 5% HCl at a temperature of 313 K, which may be associated with the hydrolysis of glycosidic bonds in an acidic environment and a corresponding change in the nature of adsorption processes. In the studied media, the inhibitor inhibits both partial electrode reactions. The calculated activation energy values indicate that the energy factor influences its anti-corrosion effect. The decrease in surface tension, angular angles and increase of thermodynamic work of adhesion with increasing inhibitor concentration in the studied media confirms its surface activity.