Unraveling the Adsorption Mechanism and Anti-Corrosion Functionality of Dextrin and Inulin as Eco-Friendly Biopolymers for the Corrosion of Reinforced Steel in 1.0 M HCl: A Thermodynamic and Kinetic Approach

Abstract

Reinforcing steel (RS) is mainly used in building construction and many industries, but it suffers from corrosion problems, especially in acidic environments. Biopolymers are characterized by their unique chemical composition, as they contain a variety of functional groups that are capable of binding strongly to the metal surface and forming a protective layer on it. Herewith, two biopolymers, viz. dextrin (Dex) and inulin (Inu), were tested as eco-friendly inhibitors for the corrosion of RS in 1.0 M HCl medium at different temperatures. Various experimental tools were utilized in this research. The inhibition efficiencies (% IEs) of the tested polymeric compounds were improved by increasing their doses while reducing with rising temperature. The % IEs of Dex and Inu at a dose of 500 mg/L reached 85% and 93%, respectively. The examined biopolymers displayed cathodic/anodic behavior (mixed type) with a foremost anodic one. The acquired higher % IEs were demonstrated by intense adsorption of Dex and Inu on the RS surface fitting the Langmuir isotherm. The influence of rising temperature in the range of 288–318 K on the corrosion behavior was examined, and the evaluated thermodynamic and kinetic parameters sustained the mechanism of physical adsorption of the polymeric inhibitors. Additionally, the kinetics of corrosion, as well as its inhibition by Dex and Inu, were also investigated. The SEM micrographs of the RS surfaces were accorded with all utilized experimental tools. The results gained from all used tools were discovered to be in good agreement with each other.

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

“…265 The adsorption process is influenced by factors such as pH, temperature, polymer concentration, and surface charge. 266 By interacting with metal surfaces through electrostatic forces, hydrogen bonds, and other molecular interactions, biopolymers can prevent corrosive substances from penetrating the surface. Due to their distinct chemical makeup, some biopolymers also have inherent corrosion-inhibiting qualities.…”

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

“…Iron and its alloys are used as building materials in a range of industrial uses, including the petroleum, electricity, and chemical industries, due to its superior mechanical durability, ease of processing, and low production cost. , Due to its high mechanical qualities and thermal conductivity, mild steel (MSL) is one of the metallic materials used for a variety of purposes, including the production of drilling equipment, storage tanks, reactors, and other devices . Hydrochloric acid is generally used in the pickling processes of metals and alloys.…”

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

“…Carbon steel is commonly exposed to acids in a variety of operations, including industrial acid cleaning, oil well acidification, acid descaling, and metal acid pickling, especially in 1.0 M HCl solution. − In such hostile settings, heterocycles are commonly utilized as corrosion inhibitors due to their wide availability and diversity, which considerably slows metal corrosion. − Metal corrosion resistance varies based on how strongly organic molecules attach to metal surfaces and prevent corrosion. − Many bonds, aromatic rings, nitrogen, sulfur, and oxygen are typically found in the most effective inhibitors . However, traditional inhibitors have drawbacks such as toxicity.…”