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Study of corrosion behaviour could benefit from quantum chemical calculation to investigate the role of adsorption of main anions such as OH⁻ and Cl⁻ on metallic surfaces. The purpose of this study is to report the quantum chemical study of aluminium immersed in NaOH, NaCl and HCl solutions and verifying the calculations by potentiodynamic and open-circuit potential (OCP) measurements.

The electrochemical evaluations based on potentiodynamic polarization and OCP experiments were carried out. For theoretical investigations, the quantum chemical calculation was performed. In this regard, the adsorption of Cl⁻, OH⁻ and H⁺ on aluminium surface was investigated. Furthermore, the natural bond orbital for the direction and magnitude of charge transfer interactions was calculated.

The calculations indicate that higher interaction energy between ions with the metallic cluster being modelled together with natural bond orbital calculations of direction and magnitude of charge transfer accurately predicts corrosion.

This paper shows that ions such as Cl⁻, OH⁻ and H⁺ cause the corrosion of aluminium in NaOH, NaCl and HCl environments. The overall theoretical data corroborate with experimental results.

Chemical and electrochemical measurements were used to study the corrosion inhibition of aluminium in distilled water using one of pyridine derivatives as corrosion inhibitor.

Corrosion inhibition of aluminum in distilled water was investigated in the absence and presence of different concentrations of 2,6-di methyl pyridine (DMP). Potentiodynamic polarization, open circuit potential and Fourier Transform Infrared Spectroscopy were employed.

Inhibition efficiency of 86 per cent is reached with 0.0187 M of DMP at 25°C. Potentiodynamic polarization showed that DMP behaves as mixed type inhibitor. The inhibitor obeyed the Langmuir adsorption isotherm. The value of ΔG°_ads suggests physico-chemical adsorption of the inhibitor molecule on the aluminium surface.

This paper indicates DMP could be used as corrosion inhibitor to prevent the corrosion of aluminium in in distilled water.

The purpose of this investigation is to study the corrosion behavior of iron and aluminum in HCl and NaOH media by means of theoretical and experimental approaches.

For theoretical investigations, the quantum chemical calculation was performed. In this regard, the adsorption of OH⁻ and Cl⁻ on iron and aluminum surfaces was investigated. Furthermore, the natural bond orbital for the direction and magnitude of charge transfer interactions were calculated. In addition, the electrochemical evaluations based on potentiodynamic experiments were carried out.

The quantum chemical calculation results showed that the charge transfer from OH⁻ to the iron surface is more than that from Cl⁻, and also the charge transfer from Cl⁻ is more than that from OH⁻ to aluminum cluster. Furthermore, these anions donate more electrons to the iron cluster than to the aluminum cluster. The experimental data showed that the rate of corrosion of iron in 1.0M NaOH solution was less than in 1.0M HCl solution. The corrosion of aluminum in HCl solution was less than that in NaOH solution. The rate of corrosion of iron in both solutions was less than that of aluminum.

The findings of this paper indicate that calculations based on the natural bond orbital analysis of the charge transfer rates from OH⁻ and Cl⁻ to the iron or aluminum surfaces, and their comparison with experimental results, exhibited excellent agreement.

The purpose of this paper was to study the corrosion resistance of AA2024 alloy using surfactant-modified halloysite nanocapsules capable of holding benzotriazole (BTA) as the corrosion inhibitor and discharging it into the solution.

The effect of surfactant shells was studied by surfactant-modified halloysite nanotubes fabricated through assembly of two types of cationic surfactants. The zeta potential and size distribution measurements were performed using a Zetasizer Nano. The concentration of BTA during release into the solution was detected by using a UV–vis spectrophotometer. The anti-corrosion activity of nanocapsules as free agents with respect to the AA2024 alloy was investigated using the potentiodynamic scan (PDS) method. An epoxy resin doped with nanocapsules was used as an anti-corrosion coating deposited on the AA2024 alloy. The corrosion protection performance of coatings was studied by using the electrochemical impedance spectroscopy (EIS) method.

The results indicate that the release of the inhibitor from nanocapsules depends on the surfactant shell components. The PDS results confirmed the feasibility of developing “smart” corrosion protection by inhibitor-loaded nanocapsules. The results of EIS measurements showed that the coating with the nanocapsules exhibited enhanced corrosion protection in comparison with the undoped coating.

The findings of this paper indicate that surfactant-modified halloysite nanocapsules can be added to epoxy resin coatings to improve their corrosion protective properties for the AA2024 alloy.

The purpose of this paper was to study the corrosion resistance of water-based sol-gel coatings containing titania nanoparticles doped with organic inhibitors for corrosion protection of AA2024 alloy.

The coatings were obtained using tetraethylorthosilicate, 3-glycidoxypropyltrimethoxysilane, titanium (IV) tetrapropoxide and poly(ethylene imine) polymer as cross-linking agents. As corrosions inhibitors, 2-mercaptobenzoxazole and salicylaldoxime were incorporated into the sol-gel for the improvement of the corrosion resistance. The corrosion protection performance of coatings was studied using the potentiodynamic scan and the electrochemical impedance spectroscopy (EIS) methods. Atomic force microscopy was used to investigate surface morphology of the coatings.

The results indicated that doping the sol-gel coatings with inhibitors leads to improvement of the corrosion protection. The comparison of doped coatings confirmed that corrosion protection performance of the sol-gel coatings doped with 2-mercaptobenzoxazole was better than for the sol-gel coatings doped with salicylaldoxime. Also the EIS results verified self-healing effects for the sol-gel coatings doped with 2-mercaptobenzoxazole.

This paper indicates 2-mercaptobenzoxazole and salicylaldoxime can be added as corrosion inhibitors to sol-gel coatings to improve their corrosion protective properties for AA2024 alloy.