A Review on Plants and Biomass Wastes as Organic Green Corrosion Inhibitors for Mild Steel in Acidic Environment

Thiol-ene Click Chemistry Synthesis of L-Cysteine-Grafted Graphene Oxide As a New Corrosion Inhibitor for Q235 Steel in Acidic Environment

l-cysteine, as an eco-friendly and nontoxic corrosion inhibitor, was directly covalently linked to the carbon/carbon double bonds of the GO flakes by a thiol-ene click reaction to avoid decreasing the number of hydrophilic oxygen-containing polar functionalities. The corrosion inhibition performances of Cys-GO toward Q235 steel (QS) in diluted hydrochloric acid were studied by electrochemical methods. The corrosion was a charge transfer-controlled process, and Cys-GO manifested as a mixed-type corrosion inhibitor. The corrosion inhibition efficiency (η) for QS showed a first-increase-and-then-decrease trend with increasing Cys-GO concentrations. The optimum concentration of Cys-GO was 15 mg L-1, and the according η value was up to 90%. The Cys-GO adsorbed on the QS surface to form a protective barrier was responsible for the efficient corrosion inhibition. Langmuir adsorption isotherm model was fitted well with the experiment data, indicating a monolayer adsorption. Furthermore, the coordinate covalent bonds, π-back-donation effect, and electrostatic attraction were responsible for the Cys-GO adsorption on the QS surface.

Greenly synthesized zeolites as sustainable materials for corrosion protection: Design, technology and application

The progress and use of effective and economic anticorrosive resources are in high mandate due to huge safety and economic concerns about corrosion. Significant advancements have already been achieved that help in minimizing corrosion costs up to US $375 to US $875 billion annually. The use of zeolites in anticorrosive and self-healing coatings is well-studied and documented in many reports. The self-healing property of zeolite-based coatings is attributed to their ability to provide anticorrosive protection in the defected areas through forming protective oxide films i.e. passivation. The synthesis of zeolites from the traditional hydrothermal method is associated with several drawbacks including their high cost and discharge of harmful gases such as oxides of nitrogen (NO_x) and greenhouse gases (CO₂ and CO). In view of this, some green approaches such as solvent-free, organotemplate-free, use of safer organic templates, green solvents (e.g. ILs) and energy efficient (MW and US) heating, one-step reactions (OSRs) etc. are adopted in the green synthesis of zeolites. Recently, the self-healing properties of greenly synthesized zeolites are documented along with their mechanism of corrosion inhibition.

Date Palm Seed Extract for Mild Steel Corrosion Prevention in HCl Medium

The inhibition effects of the date palm seed extract corrosion of mild steel in 0.5 M HCl at different concentrations are investigated by potentiodynamic polarisation (PDP), electrochemical impedance spectroscopy (EIS) and weight loss tests. Additionally, this study provides a fundamental understanding of aromatic adsorption on iron (Fe) surfaces. Furthermore, the surface morphology and the extracts are performed using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The maximum inhibition efficiency of 95, 96, and 91% were realised at 1400 mg/L for PDP, EIS, and weight loss, respectively. The inhibitive action of the DPS extract against mild steel corrosion in an acid solution has been supported by SEM analysis. The FTIR showed that the extract contained hydroxyl (−OH) and methoxyl (−OCH3) functional groups. The DFT depicted the adsorption sites at the oxygen (O) and carbon (C) atoms as deduced from the Fukui functions, Mulliken atomic charge, and the highest occupied molecular orbital-lowest occupied molecular orbital (HOMO-LUMO) analysis. The DPS preferred to form chemical bonds by donating electrons to the Fe surface. The coordinate bonds between the O and C atoms and the metal surface resulted in a high inhibition efficiency value. In conclusion, date palm seed extract is an effective inhibitor to protect mild steel from corrosion in an acidic medium.

Experimental and Theoretical Studies on Acid Corrosion Inhibition of API 5L X70 Steel with Novel 1-N-α-d-Glucopyranosyl-1H-1,2,3-Triazole Xanthines

A series of novel 1-N-α-d-glucopyranosyl-1H-1,2,3-triazole xanthines was synthesized from azido sugars (glucose, galactose, and lactose) and propargyl xanthines (theophylline and theobromine) using a typical copper (I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition. The corrosion inhibition activities of these new carbohydrate-xanthine compounds were evaluated by studying the corrosion of API 5 L X70 steel in a 1 M HCl medium. The results showed that, at 10 ppm, a 90% inhibition efficiency was reached by electrochemical impedance spectroscopy. The inhibitory efficiency of these molecules is explained by means of quantum chemical calculations of the protonated species with the solvent effect, which seems to better represent the actual situation of the experimental conditions. Some quantum chemical parameters were analyzed to characterize the inhibition performance of the tested molecules.

Review on the Recent Development of Fatty Hydrazide as Corrosion Inhibitor in Acidic Medium: Experimental and Theoretical Approaches

In recent years, numerous research work has been conducted in order to find the most practical and cost-effective solution for corrosion issues in the oil and gas industry. Several studies have revealed that fatty hydrazide derivatives are the most suitable corrosion inhibitor for the application in the said industry. These compounds can also act as effective corrosion inhibitors in acidic medium with inhibition efficiency greater than 95%. This review summarizes and discusses the recent corrosion inhibitor development in acidic media from 2017 until 2021, focusing on fatty hydrazide derivatives. The significant findings and mechanisms of inhibition have been elucidated. In addition, intake on the computer simulation studies of fatty hydrazide inhibition properties is also included in this review. Finally, some suggestions for future research on corrosion inhibitors have been recommended.