In the last two decades, fabrication of hydrophobic and superhydrophobic coatings on metals and practical application of those for self-cleaning, anti-icing, oil-water separation and especially anti-corrosion purposes has been intensively discussed in the research community. This review addresses metals and their relevant protection against corrosion under various conditions (in water, in chloride solutions, in atmosphere with aggressive components) through superhydrophobic materials and methods of fabrication of these. Under consideration are both technologically more advanced methods based on laser texturing of a metal surface or plasma etching to create multimodal roughness, followed by deposition of a layer of substance with low surface energy, primarily fluoroxysilanes, and also simpler, ordinarily environmentally friendly and less expensive approaches based on chemical etching of the metal surface, chemical or electrochemical deposition of metals of the same or different nature, followed by treatment with hydrophobising agents such as myristic or stearic acids. Studies of anti-corrosion properties of coatings were carried out predominantly by methods of electrochemical polarisation and electrochemical impedance spectroscopy and, in rare cases, by direct corrosion tests. This review mainly focuses on protection of iron, steels, copper, zinc, aluminium and magnesium.

In the present work the possibility of increasing the corrosion resistance of technically pure magnesium by way of sequential treatment in aqueous solutions of 8 mM sodium oleate and 8 mM mixture of sodium salts of alkenyl succinic acids, which are part of the anticorrosion additive KAP-25, has been investigated. The influence of surface preparation before the application of inhibitors and the sequence of their application was evaluated. It is shown that in the case of layer-by-layer treatment the most effective protection can be achieved in the case of oleate application as the first layer, and the increase in the thickness of the oxide-hydroxide sublayer has an ambiguous effect on the efficiency of the studied coatings and to a greater extent increases the protective properties of films of individual compounds.

Aluminum alloys are in high demand in various industries. In the modern world, when great emphasis is placed on environmental friendliness and the use of recycled resources, alloys based on recycled metal play an advantageous role. Such alloys may differ significantly in the amount of alloying elements. Aluminum alloy 1105, which is made from recycled aluminum, contains Mg and Cu in its composition and is characterized by a high content of impurity elements (Fe, Si, Zn). The intermetallic phases contained in the alloy reduce its corrosion resistance. Modern methods of anticorrosive protection can help the wider spread of alloy 1105 in various designs. Among the various methods, conversion coatings obtained by chemical oxidation are a simple and economical way to protect against corrosion. The aim of this work was to increase the protective properties of chromate-free conversion coatings IFKHANAL-3, by modifying them with nitrates and nitrites. One of the main problems of conversion coatings on aluminum alloy 1105 is their increased defects at the micro level. The use of nitrate and nitrite compounds provides a more effective formation of a conversion coating on the surface of the alloy, which makes it possible to enhance their corrosion resistance.

The passivation and protective properties of anti-rust additives KAP-25 and V-15/41 on lowcarbon steel St3 in chloride aqueous and borate-buffer solutions were studied. Both additives are capable of spontaneously passivating the steel electrode and improving the local depassivation potential of St3 in a borate buffer solution with the addition of 0.01 M NaCl. The highest passivation properties are possessed by V-15/41, which at 8 mmol/L has a protective effect of 0.22 V. The compositions of the studied additives with 2-MBT (9:1) have higher protective effects on low-carbon steel than the individual substances themselves. In 0.01 M chloride solutions at 7 mmol/L V-15/41+2-MBT (9:1) St3 is completely protected from corrosion destruction for 7 days. For complete protection of steel with the composition KAP-25+2-MBT (9:1) 8 mmol/L in 0.01 M NaCl solution is required.

Corrosion of technical materials, including steels of various grades and grades, proceeds by a local mechanism. Under the conditions of the equipotential surface of the corroding metal, this is explained by the different rates of dissolution at the same potential of numerous phase components that are elements of the structure. When assessing the rate of corrosion of steel, it is necessary to consider the combined influence of structural and structural-phase composition and take into account its possible changes during long-term operation.

The adsorption, protective and passivating action of sodium salts of dicarboxylic acids (succinate, itaconate, adipate and azelainate) and their compositions with 2- mercaptobenzothiazole (2-MBT) in neutral chloride solutions was studied. During the adsorption treatment of sodium succinate, itaconate and sodium azelainate on the oxidized zinc surface at the potential E = 0.2 V, adsorption isotherms were obtained with the average values of free energy adsorption 59.4, 74.3 and 73.5 kJ/mol, respectively. Polarization studies of zinc in the 0.5 mmol/L sodium succinate technology lead to spontaneous passivation of zinc, but with the development of its content and maintenance of the anodic dissolution current. Sodium itaconate, adipate and azelainate are not able to passivate zinc in the entire concentration range of the study. Corrosion tests of zinc in 0.01 M aqueous NaCl solution for 7 days showed that the best protective function is provided by a mixture of sodium adipate with 2-MBT (9:1): at Cin= 5 mmol/L, complete protection of zinc is observed for 7 days. The composition of sodium succinate+2-MBT (4:1), sodium itaconate+2-MBT (4:1) and sodium azelainate+2-MBT (9:1) at Cin = 10 mmol/L completely protects zinc from harmful effects in 0.01 M aqueous chloride solution.

The kinetics of corrosion of brass LK62-0.5 in freely aerated solutions of acetic acid (0.25−8.0 M), as well as the effect of the convective factor of the environment and the addition of a corrosion inhibitor, catamine AB, on this process were studied. The presence of a corrosion product, Cu(II) cations, has an accelerating effect on brass corrosion in the studied environments, including solutions containing catamine AB. The dependence of the brass corrosion rate on the convective factor in freely aerated acid solutions and acid solutions containing Cu(II) cations is formally described by an equation of the form k = a+b·n1/2, where a and b are empirical parameters, n is the rotation frequency of the propeller magnetic stirrer stirring the solution. In acetic acid solutions, including stirred environments containing Cu(II) cations, the brass corrosion rate does not exceed 0.91 g/(m2·h). In the same environments containing the additive catamine AB, the corrosion rate of brass does not exceed 0.14 g/(m2·h). Considering the low corrosion rate of brass in inhibited acidic environments, the obtained result is of practical interest.

This study aims to develop a novel volatile corrosion inhibitor for mild steel by preparing a nanocomposite (ZIF-AD) through a salt-forming reaction between aspartic acid (AD) and din-butylamine, with zeolitic imidazolate framework-8 (ZIF-8) as the template material. The ZIF-8's porous structure is beneficial to disperse AD molecules, reducing agglomeration and enhancing volatility. Under ambient atmosphere, ZIF-AD achieves corrosion inhibition properties through volatilization and adsorption. It demonstrates that a protective film is formed on mild steel surfaces, effectively inhibiting the cathodic process of corrosion. Compared to AD alone, the incorporation of ZIF-8 increased the inhibition efficiency to 91%. These findings highlight the potential of ZIF-AD as a highly efficient corrosion inhibitor for mild steel in atmospheric environments.

The mutual influence of different functional organic additives in sulfate electrolyte of copper plating during co-adsorption on the surface of copper cathode was investigated by ellipsometric method. The work studies the kinetics of adsorption on a copper electrode from a sulfate solution of three-component mixtures composed of organic additives (Inhibitors) – PEG-8000 and PEG-115, (Leveler) – Janus green B (YaZ), (Brightener) – Avangard and AFDS (bis(2-aminophenyl) disulfide), which has a disulfide bond in its structure, using the ellipsometric method. It is shown that the introduction of AFDS into the three-component mixture a more stimulating effect of APhDS addition on adsorption was observed instead of Avangard of the mixture.