Experimental and Computational Exploration of Chitin, Pectin, and Amylopectin Polymers as Efficient Eco-Friendly Corrosion Inhibitors for Mild Steel in an Acidic Environment: Kinetic, Thermodynamic, and Mechanistic Aspects

Abstract

Herein, the inhibition impacts of chitin, pectin, and amylopectin as carbohydrate polymers on the corrosion of mild steel in 0.5 M HCl were researched utilizing various experimental and theoretical tools. The acquired outcomes showed that the inhibition efficiencies (% IEs) of the tested carbohydrate polymers were increased by raising their concentrations and these biopolymers acting as mixed-kind inhibitors with major anodic ones. The acquired % IEs values were reduced with rising temperature. The higher % IEs of the tested polymers were inferred via powerful adsorption of the polymeric molecules on the steel surface and such adsorption obeyed the Langmuir isotherm. The computed thermodynamic and kinetic quantities confirmed the mechanism of physical adsorption. The kinetics and mechanisms of corrosion and its protection by polymeric compounds were illuminated. The results obtained from all the techniques used confirmed that there was good agreement with each other, and that the % of IEs followed the sequence: chitin > amylopectin > pectin.

Effect of Adsorption and Interactions of New Triazole-Thione-Schiff Bases on the Corrosion Rate of Carbon Steel in 1 M HCl Solution: Theoretical and Experimental Evaluation

“…The high K ads values in Table show that Schiff base inhibitors have a high capacity for adsorption on the surface of carbon steel. Using the relationship shown below, the standard free energy of adsorption (Δ G ads o ) was calculated: K ads = 1 55.5 exp ( − Δ G ads normalo R T ) where 55.5 represents the concentration of water in the solution (in mol/L), R represents the universal gas constant (8.314 J/mol K), and T represents the absolute temperature (in Kelvin).…”

Cysteine as an Eco-Friendly Anticorrosion Inhibitor for Mild Steel in Various Acidic Solutions: Electrochemical, Adsorption, Surface Analysis, and Quantum Chemical Calculations

“…Fe inh (15) The signs χ in and χ Fe , respectively, symbolize the final electronegativity values for Cys. and MSL.…”

“…When present in the corrosive medium at an appropriate concentration, inhibitors, which function at the interface of the corrosive media and the metal surface, slow the pace of metal corrosion. Numerous organic compounds with long carbon chains or aromatic rings including hetero atoms like nitrogen, oxygen, sulfur, and phosphorus have been used as potential corrosion inhibitors in acid solutions. − The physicochemical characteristics of the inhibitor, such as the functional groups, steric factors, aromaticity, electron density at the donor atoms, the π-orbital nature of donating electrons, the structure of the molecule, the corrosion environment, and the charge and nature of the metal, are what primarily determine the inhibitor’s ability to inhibit. , Amino acids are naturally occurring, biodegradable, relatively inexpensive, and synthesized with a high purity level of greater than 99%. They also represent a family of nontoxic, water-soluble chemical compounds .…”

Principles and theories of green chemistry for corrosion science and engineering: design and application

“…Multiple research studies have provided compelling evidence of the anti-corrosive capabilities of chitosan, particularly in safeguarding mild steel and various other metal types. 713,714 Research into the functionalization of chitosan has unveiled a remarkable enhancement in its anti-corrosive properties. Chitosan derivatives have undergone comprehensive examination as aqueous corrosion inhibitors across various solutions and for diverse metal types, consistently demonstrating exceptional %IE values that outweigh its pure forms.…”