Inhibitive effect of different solvent fractions of bamboo shoots extract on the corrosion of mild steel in 0.5 mol/L H2SO4 solution

Unveiling green corrosion inhibitor of Aloe vera extracts for API 5L steel in seawater environment

This study evaluated Aloe vera extract as a green inhibitor to prevent corrosion in seawater environments. A. vera extract was produced by maceration with methanol-water at room temperature. Electrochemical techniques were used to evaluate the corrosion inhibitor effectiveness of the A. vera extract. The morphology of the corrosion products was analyzed by FE-SEM equipped with EDS and AFM. FT-IR and LCMS characterized the functional and structural groups in this extract. The electrochemical measurements show that A. vera extract could effectively reduce the corrosion of API 5L steel in seawater environments. Inhibition efficiency (IE) increases with increasing concentration. Optimal corrosion inhibition efficiency of around 83.75% (PDP) and 88.60% (EIS) was obtained by adding 300 mg L-1 of extract at 310 K. Furthermore, the higher the concentration of A. vera extract, the greater the activation energy (Ea), with the highest activation energy being 48.24 kJ mol-1 for the concentration of 300 mg L-1. Conversely, increasing the temperature and exposure duration reduces the corrosion inhibition efficiency (IE) values; the best exposure period was 30 min with 88.34% IE by a concentration of 300 mg L-1 at 300 K. This corrosion inhibition is achieved by the adsorption process of A. vera bioactive on metal surfaces with a mixed inhibitor through a physisorption-chemisorption mechanism. This finding was confirmed by the smoother surface morphology of the steel treated with A. vera extract than without. This unveiling investigation found that A. vera extract has the potential to be an environmentally friendly corrosion inhibitor in the seawater environment.

Corrosion resistance and antibacterial activity of procyanidin B2 as a novel environment-friendly inhibitor for Q235 steel in 1 M HCl solution

Flavonoids, alkaloids, glucosides and tannins with good corrosion inhibition are the main natural components in plants. In this work, procyanidin B2 (PCB2), a natural flavonoid, was firstly isolated from Uncaria laevigata. Corrosion inhibition, chemical reactivity and adsorption of PCB2 on Q235 carbon steel were described by experimental and theoretical studies. The inhibition performance of PCB2 as a green corrosion inhibitor was evaluated by electrochemical and gravimetric tests. The binding active sites and activities thereof on the steel surface were illustrated by quantum chemistry, and the equilibrium configuration was predicted by molecular dynamics simulation. PCB2 exhibits good corrosion inhibition on Q235 steel over a wide temperature range. The electrochemical results show that PCB2 is a mixed inhibitor, and its inhibition efficiency increases with the addition of PCB2 concentration. Moreover, the protective film is formed on the steel and the active corrosion sites are blocked significantly by surface analysis. Additionally, the theoretical calculation proves a strong interaction between PCB2 molecule and carbon steel. Besides, the antimicrobial activity was also preliminarily studied. This suggests that PCB2 exhibits better antimicrobial activity against many Gram-positive and Gram-negative bacteria. As a novel green corrosion inhibitor and antimicrobial agent, PCB2 is worthy of further exploitation.

Corrosion Inhibition in Acidic Environments: Key Interfacial Insights with Photoelectron Spectroscopy

In many engineering scenarios, surface-active organic species are added to acidic solutions to inhibit the corrosion of metallic components. Given suitable selection, such corrosion inhibitors are highly effective, preventing significant...