Anti-Corrosion Coating Formation by a Biopolymeric Extract of Artemisia herba-alba Plant: Experimental and Theoretical Investigations

In this modest work, a local biopolymer (CHA), biodegradable, non-toxic, and soluble in acidic media, was extracted from the plant Artemisia herba-alba located in the eastern region of Morocco, and characterized by FT-IR, in order to valorize it as a corrosion inhibitor of mild steel in 1 M HCl medium. The electrochemical tests show that the extract is an excellent corrosion protective agent, reaching a maximum value of 96.17% at the concentration of 800 mg/L in the inhibitor. The potentiodynamic polarization (PDP) curves indicate the mixed behavior of the extract, to reduce the current density from 3.445 mA/cm(2) to 0.104 mA/cm(2) in the presence of 800 mg/L in the inhibitor. The biopolymer CHA of the extract of Artemisia herba-alba undergoes the Langmuir adsorption isotherm, whose adsorption energy is -20.75 kJ/mol, which is attributed to the presence of electrostatic and covalent bonds. In addition, the visualization of the metal surface by a scanning electron microscope (SEM) indicates the formation of a protective layer formed by the extracts of Artemisia herba-alba, which confirms the protective characteristic of the extract used. Theoretical investigations by DFT, MD, and MC confirm previous experimental results.

Automated summary

In this study, a biopolymer (CHA) was extracted from Artemisia herba-alba plant in Morocco and characterized. The extracted CHA exhibited excellent corrosion inhibition properties for mild steel in 1 M HCl medium, with a maximum inhibition efficiency of 96.17% at a concentration of 800 mg/L. The Langmuir adsorption isotherm was observed for CHA, indicating the presence of electrostatic and covalent bonds. The protective layer formed by the extract on the metal surface was confirmed by SEM analysis.