Green and nano-based strategies for controlling mild steel corrosion in acidic media: a systematic review

Lemon seeds as green coating material for mitigation of mild steel corrosion in acid media: Molecular dynamics simulations, quantum chemical calculations and electrochemical studies

Green corrosion inhibitors are produced from economical and renewable sources and concurrently offer high inhibition efficiency and very low negative effects on environment. Various naturally occurring biomacromolecules are employed as corrosion inhibitors for steels. In contrast to small molecule corrosion inhibitors, polymers possess superior film-forming abilities and multifunctional chemistries that have the potential to enhance protective barrier characteristics greatly. Moreover, the biomacromolecules have many sites of attachment which further enhance their inhibition ability. This featured article is dedicated to summarizing the inhibition performance of biomacromolecules to mitigate mild steel corrosion in acidic media. It began by describing the green corrosion inhibitors and the advantages of using biomacromolecules as inhibitors. All naturally occurring macromolecules such as such as carbohydrates, proteins, and nucleic acids, have been focused as inhibitors for mild steel in acidic media with their inhibition action. The factors affecting inhibition efficiency like temperature, inhibitor concentration, exposure time, etc. are also discussed. In the last, the synergistic effect of other ions with macromolecules in corrosion inhibition was also taken into consideration. This review offers insightful observations into the development of biomacromolecules as green corrosion inhibitors.

Inhibition of mild steel corrosion in acidic medium using synthetic and naturally occurring polymers and synergistic halide additives

Grafting effect of gum acacia on mild steel corrosion in acidic medium: Gravimetric and electrochemical study

In the realm of corrosion mitigation, the search for sustainable and ecologically accountable inhibitors attracts significant interest from the environmental point of view. This study investigates the intriguing possibilities presented by Erigeron bonariensis (EB) as a green and innovative corrosion inhibitor for weathering steel in 1 M H2SO4. EB, a naturally abundant plant species, holds promise as a green and sustainable inhibitor due to its inherent chemical composition in the environment. The intricate interplay between the phytochemical constituents of the extract and the corrosive environment is meticulously deciphered. Furthermore, the environmentally benign nature of the inhibitor adds an extra layer of significance to its application, aligning with contemporary green chemistry principles. The inhibition effect of Erigeron bonariensis (EB) extract on the corrosion of mild steel in acidic media (H2SO4) was studied using weight loss, absorption studies, phytochemical analysis, electrochemical methods, and scanning electron microscopy. The experimental findings revealed that an increase in inhibitor concentration is correlated with higher inhibition efficiency. The adsorption of inhibitor molecules on the mild steel surface was found to agree with the UV-Vis adsorption spectrum. Additionally, a surface study conducted using scanning electron microscopy indicated notable differences in the presence and absence of inhibitors for weathering steel. At 2000 mg L-1, EB extract has the best inhibitory efficiency for weathering steel in 1 M H2SO4 of 99.50% by the leaf part, followed by 94.35% by the flower part, and 85.22% by the stem part. Overall, this study suggests that EB extract serves as a promising alternative for corrosion prevention, demonstrating significant inhibition efficiency.

In this research, the efficiency of two Schiff bases (SB-I and SB-II) as inhibitors of carbon steel corrosion in acidic medium was investigated to find the relationship between molecular structure parameters and the experimental percentage inhibition efficiencies. The computational data and experimental IE% were subjected to correlation analysis, demonstrating that the effect of the inhibitors is strongly linked to electronic properties, including the energies of frontier molecular orbitals (HOMO and LUMO energy), energy band gap (∆Egap), dipole moment ( $$\mu$$ ), electronegativity ( $$\chi$$ ), electron affinity (A), global hardness (η), softness (σ), ionization potential (I), fraction of electrons transferred from inhibitor molecules to metallic atoms (∆N), and total energy. In addition, we used natural bond orbital analysis to obtain the Fukui functions. The results were also investigated to estimate the significance of the nitrogen and oxygen atoms for the preventive effect. There was found to be good correlation between the theoretically obtained data and reported empirical data.

Two 3-chloromethylcoumarins synthesized via the Baylis-Hillman reaction have been investigated for their ability to inhibit corrosion of mild steel in 2.0 M HCl. The inhibition efficiency was evaluated by gravimetric and electrochemical methods. Inhibition efficiency was found to increase with increase in concentration of the 3-chloromethylcoumarins. Kinetics, thermodynamics and adsorption equilibrium of the corrosion of steel in the acid and acid-containing 3-chloromethylcoumarins media were investigated. The results showed that the inhibitive actions of the compounds occurred as a result of adsorption of 3-chloromethylcoumarins molecules on mild steel surface. 3-Chloromethyl-8-ethoxycoumarin 4a showed higher inhibition efficiencies than 6-chloro-3-chloromethylcoumarin 4b, especially at low concentrations and temperatures. Physical adsorption was predicted based on decreasing surface coverage of the inhibitor molecules with increase in temperature. The studied 3-chloromethylcoumarins behaved as mixed-type corrosion inhibitors for mild steel in 2 M HCl. The higher electron-donating ability and lower energy gap of 4a compared to 4b, as derived from computational studies suggest that 4a has higher potentials to inhibit steel corrosion in HCl than 4b. Similar trend was reflected in the Monte Carlo simulations adsorption energies.

New pyrimidine derivatives as efficient organic inhibitors on mild steel corrosion in acidic medium: Electrochemical, SEM, EDX, AFM and DFT studies

The corrosion inhibition potentials of gum exudates from Daniella oliveri (DO) and Commiphora Africana (CA) for the corrosion of mild steel in H2 SO4 have been studied using weight loss and thermometric methods at 303 and 333K. Results show that the exudates gum actually reduced the rates of corrosion of mild steel. Increase in the concentrations of the exudate’s gums increased their percentage inhibition efficiencies. Corrosion rate was found to increase with increase in temperature in the presence and absence of the gum exudates, though the corrosion rate was slower in the presence of the exudates gums. Both DO and CA exudates gums were found to obey Temkin and Langmuir adsorption models at all concentrations and temperatures studied. Physical adsorption mechanism was proposed from the adsorption parameters. Kinetic and thermodynamic parameters revealed that the adsorption process is spontaneous, exothermic and no significant difference was found between the inhibition efficiencies of DO and CA.

Green Approach to Corrosion Inhibition of Mild Steel by Lignin Sulfonate in Acidic Media

The inhibition effect of 5′ ‐phenyl‐2′ ,4′ ‐dihydrospiro[indole‐3,3′ ‐pyrazol]‐2(1H)‐one (SPAH) on mild steel corrosion in 1 M HCl and 0.5 M H2SO4 has been studied by weight loss, effect of temperature, electrochemical techniques, and quantum chemical studies. The inhibition efficiency increases with increasing concentration of inhibitor but decreases with increase in temperature. The adsorption of inhibitor on mild steel surface has been found to obey Langmuir and Temkin’s adsorption isotherm. Potentiostatic polarization results revealed that SPAH acts as mixed type inhibitor. The values of activation energy (Ea), free energy of adsorption (ΔG∘), enthalpy of adsorption (ΔH), and entropy of adsorption (ΔS) were calculated. Surface analysis (SEM) was also carried out to establish the mechanism of inhibitor on mild steel corrosion in acid medium. Quantum chemical studies using DFT were employed to explain the experimental results obtained in this study and to further give insight into the inhibition action of SPAH on the mild steel surface.

1((Cyclohexylamino)methyl)urea Mannich base was synthesized and characterized using FT-IR, H1NMR and C13NMR spectra and it was tested as a corrosion inhibitor for mild steel in 1 N HCl and 1 N H2SO4 solutions using potentiodynamic polarization and AC impedance techniques over the temperature range of 303–333 K. The inhibition efficiency was increased with respect to concentration of inhibitor and temperature in 1 N HCl, whereas the inhibition efficiency was increased with respect to concentration of inhibitor and decreased with respect to temperature in 1 N H2SO4. Potentiodynamic polarization results revealed that the inhibitor acts as mixed type inhibitor. AC impedance study indicates that the corrosion of steel was mainly controlled by a charge transfer process. Surface analysis was carried out using SEM technique. The adsorption of inhibitor follows Langmuir adsorption isotherm. Activation and adsorption parameters were calculated to gain information about the inhibitive action mechanism.

N′-[4-(diethylamino)benzylidine]-3-{[8-(trifluoromethyl) quinolin-4-yl]thio}propano hydrazide) as an effective inhibitor of mild steel corrosion in acid media

<p class="PaperAbstract"><span lang="EN-US">Corrosion of metals is a common problem which requires definite attention. In response to this, the oil was extracted from the seed of </span><span lang="EN-US">Terminalia catappa</span><span lang="EN-US"> and used to synthesize sucrose fatty esters via simple reaction mechanism which was considered eco-friendly and sustainable. The corrosion inhibition capacity of sucrose fatty esters for mild steel in 1 M HCl was studied using the weight loss method. It was shown that sucrose fatty ester inhibited corrosion process of mild steel and obeyed Langmuir isotherm. Corrosion rate and inhibition efficiency of sucrose fatty esters were found to reduce with increase of immersion time. The study presented sucrose fatty ester as a promising inhibitor of mild steel corrosion in acidic medium.</span></p>

The synergistic inhibition effect of Tween-80 and 1,2,3,4-tetrahydroacridines, including 9-(4-chlorophenyl)-2-methyl-1,2,3,4-tetrahydroacridine (CMT) and ethyl 9-(4-chlorophenyl)-1,2,3,4-tetrahydroacridine-2-carboxylate (ECT), on mild steel corrosion in 1 M HCl was investigated by using weight loss tests, electrochemical techniques, and surface morphology (SEM/SECM). The results indicated that the mixtures of CMT/ECT and Tween-80 strongly inhibit the corrosion of mild steel compared to individual inhibitors, and the adsorption mode belongs to the Langmuir isothermal type. Electrochemical measurements showed that the mixtures were mixed-type inhibitors, and a double-layer structure film with the inner layer of Tween-80 and the outer layer of CMT/ECT was formed on the steel surface. That the calculated synergistic parameter value was larger than unity illustrates that the enhancement of inhibition in the presence of Tween-80 is only due to synergistic action. Surface analysis techniques (SEM/SECM) verified ...