Evaluation of inhibition efficiency of oak galls extract as a green corrosion inhibitor of archaeological iron artifacts in the atmospheric environment

Abstract

The aim of this work is to investigate the effectiveness of oak galls extract (OGE) as a green corrosion inhibitor from natural resources to prevent the corrosion of archaeological iron artifacts in atmospheric environments. The inhibition efficiency has been evaluated by measuring the weight loss of the treated coupons after exposure to 85% RH in a humidity chamber, Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. Also, the morphology of an adsorbed film on the surface was investigated by scanning electron microscopy and optical microscope. The influence of OGE on changing the original appearance of the surface was also evaluated using visual examination and colorimetric measurements. The measurements results revealed that OGE gave high inhibition efficiency reaching approximately 95% of 6% concentration. Based on the study results, OGE can be proposed as an efficient green inhibitor for iron artifacts.