Corrosion protection of Q235 steel in acidic-chloride media using seed extracts of Piper guineense

Aromaticity of Heterocyclic Compounds and Their Corrosion Inhibition Property: Experimental and Theoretical Analysis

Heterocycle derived moieties, namely, N-(4-methoxyphenyl)-1-(1H-pyrrol-2-yl)methanimine (MPM), 1-(furan-2-yl)-N-(4-methoxyphenyl)methanimine (FMM), and N-(4-methoxyphenyl)-1-(thiophen-2-yl)methanimine (MTM), were synthesized followed by analysis of their structural aspects using FTIR and 1H NMR spectroscopic techniques. The corrosion retarding abilities of the same were distinguished by gravimetric and certain electrochemical measures for mild steel in 0.5 M H2SO4, and MTM was obtained with maximum inhibition efficiency of 97.93% at 250 mg L-1 concentration; the thermodynamic and activation parameters were recorded in this regard. The results were further seen to be supported by various surface studies: SEM-EDS, XPS, AFM, contact angle, and UV-visible spectroscopy. Potentiodynamic polarization studies unveiled the mixed nature of heterocyclic inhibitors with overriding anodic effect. Furthermore, the adsorption of inhibitors over mild steel coupons demarcates the prevalence of physical and chemical interactions in the environment. In addition, the computational studies, global and local reactivity, molecular dynamics, and density functional theory, were employed and the experimental results obtained were found in correlation with the theoretical results.

Unveiling the corrosion inhibition efficacy and stability of silver nanoparticles synthesized using Anacardium occidentale leaf extract for mild steel in a simulated seawater solution

Plant extracts used as corrosion inhibitor for mild steel usually degrade as the temperature increases above room temperature. In this study, we used Anacardium occidentale (cashew leaf) extract to synthesize silver nanoparticles for improving mild steel's inhibition stability under salinized conditions. Cashew leaves were used as a reducing agent to synthesise silver nanoparticles. The functional group of the silver nanoparticles was determined using Fourier transform infrared spectroscopy. Electrochemical impedance spectroscopy and potentiodynamic polarisation were used to study the corrosion behaviour under simulated seawater by varying the silver nanoparticle concentration between 0.1 and 0.3 g L-1. Scanning electron microscopy and atomic force microscopy were used to obtain information about the surface of the corroded sample. The green silver nanoparticles reduced the corrosion of mild steel up to 90.5% at 40 °C and 90% at 80 °C. At 80 °C, the AgNPs are biochemically and thermally stable, exhibiting a 90% inhibition efficiency. It was established that silver nanoparticles from cashew leaves can be used to improve the stability of mild steel in simulated seawater.

Unveiling the multifaceted incorporation of Musa acuminata peduncle juice as a bio-corrosion inhibitor of mild steel in seawater-simulated solution

This work assessed the ability of Musa acuminata peduncle juice extract to sustainably inhibit mild steel under salinized conditions. The effort sought to ascertain the new active material's inhibitory efficacy for inhibiting metal corrosion in seawater. M. acuminata peduncle juice was extracted from the M. acuminata peduncle. The functional group of the M. acuminata pedal juice was determined using Fourier transform infrared spectroscopy. The corrosion behavior was assessed using electrochemical impedance spectroscopy and potentiodynamic polarization by varying the M. acuminata peduncle juice at 0.1, 0.2, and 0.3 g L-1 for 300 K, 310 K, and 320 K, respectively. Scanning electron microscopy provided an image of the surface morphology of mild steel. Reduced corrosion current (icorr) was observed when M. acuminata pedal juice was present according to potentiodynamic polarization and studies. Moreover, adding M. acuminata peduncle juice increases resistance capacity transfer (Rct). The potentiodynamic polarization approach was used to obtain the optimum inhibitory efficiency (%IE) at 0.3 g L-1 doses with 88.0% efficiency at 300 K. The addition of M. acuminata peduncle juice results in a smoother, mild steel morphology than the surface without inhibitor additions. The molecules of active chemicals adhering to the steel surface were linked to increased corrosion inhibition. The study's findings demonstrated that M. acuminata peduncle juice is a promising biomaterial for mild steel corrosion inhibitors in a salty environment.

Design of New Ecofriendly Schiff Base Inhibitors for Carbon Steel Corrosion Protection in Acidic Solutions: Electrochemical, Surface, and Theoretical Studies

Corrosion poses a significant problem for several industrial sectors, inducing continuous research and development of corrosion inhibitors for use across a wide range of industrial applications. Here, we report the effectiveness of three newly developed Schiff bases derived from amino acids and 4-aminoacetophenone, namely, AIP, AMB, and AImP, as environmentally friendly corrosion inhibitors for Q235 steel in hydrochloric acid using electrochemical and surface analyses, in addition to theoretical techniques. The electrochemical findings of potentiodynamic polarization (PDP) demonstrated that the explored compounds serve as mixed-type inhibitors and can effectively suppress steel corrosion, with maximal protection efficiencies of 93.15, 96.01, and 77.03% in the presence of AIP, AMB, and AImP, respectively, at a concentration of 10 mM. The electrochemical impedance spectroscopy (EIS) and polarization results confirmed the growth of a durable protective barrier on the steel surface in the existence of the inhibitors, which is responsible for decreasing the metallic dissolution. Results were further supported by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), UV-vis, and Fourier transform infrared (FTIR), which ascribed the development of inhibitor-adsorption films on the steel surface. The results of EDS and XPS analyses demonstrated the existence of the distinctive elements of the inhibitors on the metallic surface. Furthermore, density functional theory (DFT) calculations and Monte Carlo (MC) simulations showed the electronic structure of the examined inhibitors and their optimized adsorption configurations on the steel surface, which helped in explaining the anticorrosion mechanism. Finally, the theoretical and experimental findings exhibit a high degree of consistency.