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L-Glutathione reduced (GSH) is a small molecule peptide found in large quantities in living organisms, particularly in animal liver cells. Its unique structure gives it great potential to act as an environmentally friendly and efficient corrosion inhibitor. The inhibition properties of GSH for mild steel in simulated concrete pore solutions (SCPS) containing chlorine was investigated by electrochemical tests and SEM-EDS surface analysis. According to the experimental results, GSH mainly blocked the cathodic corrosion reaction and has a corrosion inhibition efficiency of up to 92.3% at room temperature, enhancing the corrosion resistance of mild steel. The isothermal adsorption results indicate that the adsorption behavior of GSH on the surface follows the Langmuir isothermal adsorption model. Both quantum chemical calculations (QC) and molecular dynamics simulations (MD) show that GSH can be effectively adsorbed onto mild steel substrates, thus protecting the surface from erosion. Finally, the results of the above experiments and theoretical calculations are combined to elucidate the inhibitive mechanism: GSH molecules binds to the iron surface via the sulfur, nitrogen and oxygen atoms in the molecule, thus adsorbing to the iron surface in a tiled manner and forming a protective film to prevent the corrosive material from contacting the iron surface. [ABSTRACT FROM AUTHOR]

Corrosion presents a substantial hurdle in the oil and gas industry, and corrosion inhibitors represent an economically viable strategy for control and prevention. As operating conditions in oil and gas extraction become increasingly harsh, factors such as cost, availability, and service temperature significantly influence inhibitor selection. While there is a wealth of literature on organic corrosion inhibitors, many exhibit a notable decrease in effectiveness at elevated temperatures, hindering their industrial application. To address this issue, we synthesized a novel Schiff base derivative, 1-((E)-(4-chlorophenylimino)methyl)naphthalen-2-ol (E4CMN), and investigated its effectiveness in inhibiting corrosion on Q235 immersed in a 1 M HCl. E4CMN adsorbs onto the surface by forming strong π-d interactions with Fe through the delocalized π electrons in its conjugated structure, effectively blocking the attack of corrosive particles towards the metal surface and consequently suppressing metal corrosion. Our study demonstrates that E4CMN exhibits maximum efficiencies of 96.9 % at a concentration of 250 mg L−1. Importantly, E4CMN shows insensitivity to service temperature, maintaining an 84.4 % corrosion inhibition efficiency even when exposed to 75 °C. This work provides novel insights into mechanism of inhibition of mild steel corrosion by Schiff base derivatives in acidic environments and offers valuable considerations for the development and selection of corrosion inhibitors for high-temperature applications. • E4CMN synthesized via a nucleophilic addition-elimination reaction. • E4CMN achieves a maximum inhibition efficiency of 96.9 % at 250 mg L−1. • E4CMN inhibits carbon steel corrosion in 1 M HCl with 84.4 % efficiency at 75 °C. • Strong π-d interactions between E4CMN and Fe atoms elucidate its adsorption mechanism. [ABSTRACT FROM AUTHOR]

• Synthesized and evaluated two isoindigo derivatives as corrosion inhibitors. • Derivatives were effective corrosion inhibitors on carbon steel in acidic conditions. • Protective film is formed on the steel surface by the interaction of N and Fe atoms. • Offers new insights into inhibitors development and broadens the use of isoindigo. This investigation synthesized two isoindigo derivatives (IIDBr-NBr and IIDBr-MBr). These derivatives were then applied as green corrosion inhibitors for mild steel in a 1 mol L−1 HCl aqueous solution. The study investigated the corrosion inhibition performance of IIDBr-NBr and IIDBr-MBr through electrochemical and weight loss (WL) measurements, as well as surface analysis (SEM, AFM and XPS). The results showed that both IIDBr-NBr and IIDBr-MBr exhibited excellent corrosion inhibition performance (inhibition efficiency of 96.27 % for IIDBr-NBr and 96.46 % for IIDBr-MBr). Quantum chemical calculations based on density functional theory (DFT) and molecular dynamics (MD) were used to reveal the adsorption mechanisms of IIDBr-NBr and IIDBr-MBr at the steel/solution interface. [Display omitted] [ABSTRACT FROM AUTHOR]

When using HCl to remove oxidation from metal surfaces, there is a risk of significant corrosion to the metal substrate. As a common industrial practice, organic or polymer coatings in corrosive environments protect metals from corrosion by providing a barrier on the metal surface within the corrosive medium. However, the limited solubility of polymers in aqueous corrosive mediums restricts their effectiveness. Herein, a highly water-soluble polyfluorene derivative, Poly(9,9-bis{3′-[(N , N -dimethyl)- N -ethylammonium}-propyl]-2,7-fluorene dibromide) (PFDN-Br), was synthesized as a HCl corrosion inhibitor to solve the corrosion problem of Q235 steel. The protective performance of the synthesized coatings was evaluated through electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) curves. The results of electrochemical testing demonstrate that the addition of PFDN-Br significantly reduces the corrosion rate of mild steel compared to the results without PFDN-Br. The average inhibition efficiency is 92.7 %. Additionally, the results of PDP indicate that PFDN-Br acts as a mixed-type corrosion inhibitor, with its adsorption on the surface of carbon steel following the Langmuir adsorption isotherm model. Quantum chemistry calculations (QC) and molecular dynamics simulations (MD) were employed to investigate the interaction mechanism between PFDN-Br and the surface. The excellent inhibitory performance of PFDN-Br may be attributed to its high-density side chains. This study provides insights into the development of polymer coatings with high water solubility and superior corrosion resistance. • Synthesized a highly water-soluble cationic Polyfluorene PFDN-Br. • PFDN-Br coating protects metals from acid corrosion. • After 10 h of immersion, PFDN-Br maintains a corrosion inhibition rate of 93 %. • The adsorption mechanism of PFDN-Br was elucidated through theoretical calculations. [ABSTRACT FROM AUTHOR]