Method for producing corrosion-inhibiting coatings for metals, coatings obtainable thereby and use thereof as corrosion inhibitors for metals

Abstract

The invention relates to a method for producing a corrosion-inhibiting coating (3) for a metal (1), comprising the following steps: i) diluting a surfactant (4); ii) adding a metal precursor (5); iii) reducing the metal precursor (5); iv) forming a nanostructured lattice (31) of a surfactant (4) and a reduced metal precursor (5) on the surface (2) of the metal (1); v) removing the surfactant (4) by washing, thereby obtaining the coating (3) of the reduced metal precursor (5) having a mesoporous structure (32), such that it prevents corrosion of the metal (1). The invention also relates to a coating (3) obtainable by said method and to the use of said coating (3) as a corrosion-inhibiting coating for metals (1).

Description

[0001] Purpose of the Invention

[0002] The present patent application lies in the field of nanotechnology and materials science and relates to a method for producing a corrosion-inhibiting coating for metals, comprising the following steps: i) diluting a surfactant; ii) adding a metal precursor; iii) reducing the metal precursor; iv) forming a nanostructured lattice on the surface of the metal; and v) removing the surfactant by washing, thereby obtaining a corrosion-inhibiting coating having significant advantages. Further objects of the invention relate to the coating obtainable by said method and its use as a corrosion inhibitor. Background of the Invention

[0004] Corrosion is the deterioration of metal structures due to the reaction of metals with their environment. A 1970s British government estimate of the economic costs of corrosion and protection of materials concluded that the cost of repairing damaged structures was approximately 3% of gross domestic product (GDP). A more recent study by the National Association of Corrosion Engineers (NACE) in the United States estimated the global cost of corrosion at approximately $2.5 trillion, equivalent to 3.4% of global GDP.

[0005] Today, corrosion is considered a significant industrial problem because it can lead to accidents when components break and represents significant costs both economically and environmentally. Corrosion is a spontaneous electrochemical redox reaction in which, similar to batteries, two reactions occur: oxidation at the anode, i.e., corrosion of the manufactured material, and simultaneous reduction of a substance, which is usually molecular oxygen, at the cathode. Therefore, for corrosion to occur, these two reactions are necessary: at the anode and at the cathode. To prevent the corrosion process at the anode, attention has currently focused on slowing down the corrosion by protecting the anode with paint, alloys, or coatings, while the possibility of suppressing the reduction reaction of molecular oxygen at the cathode has been overlooked.

[0006] The illustrative literature known in the prior art is the content described in patent CN114774830, which describes a multifunctional coating, a method for preparing the same, and a power device. The multifunctional coating includes an abrasive surface layer, a metal transition layer, a ceramic intermediate layer, and a lower bonding layer arranged in a stacked mode. The method for preparing the multifunctional coating includes the steps of sequentially preparing a lower bonding layer, a ceramic intermediate layer, a metal transition layer, and an abrasive surface layer on a working surface by a thermal spraying process. The power device includes a multifunctional coating. The multifunctional coating provided by the invention has the triple functions of marine corrosion resistance, gap control, and titanium fire resistance, overcomes the defect of existing coatings that are not corrosion-resistant, and can meet the use requirements of high-performance aircraft engines and gas turbines.

[0007] Therefore, and in view of the above, there remains a need to minimize the corrosion process. Summary of the Invention

[0008] The purpose of the present invention is to minimize corrosion phenomena, which are a major industrial problem since they can lead to accidents such as the breakage of components and represent huge costs; it is estimated that in just a few seconds five tons of steel dissolve worldwide.

[0009] In particular, and in contrast to the strategies usually used in the prior art to solve corrosion, the solution proposed by the present invention is based on suppressing the oxygen reduction reaction, for which purpose a specific surface atomic structure is developed on the material to be protected so as not to allow it to interact with molecular oxygen, thereby suppressing the reaction at the cathode and thus preventing corrosion of the material.

[0010] Corrosion is defined as the degradation of a material due to electrochemical attack by its environment. Corrosion is a spontaneous electrochemical redox reaction in which, similar to a battery, two reactions occur: oxidation of the manufactured material at the anode, i.e., corrosion, and reduction of a substance (mostly molecular oxygen) at the cathode. It is important to emphasize that for corrosion to occur, both reactions must occur: at the anode and at the cathode.

[0011] Currently, the greatest technological efforts to delay corrosion focus on protecting the anode by coating with paint, alloys, or other less expensive materials. However, the present invention focuses on inhibiting the reduction reaction of molecular oxygen at the cathode. To this end, a specific surface atomic structure is developed on the material to be protected that does not allow the material to interact with oxygen, thereby inhibiting any reaction at the cathode and, subsequently, the corrosion of the material.

[0012] In particular, the method for producing a corrosion-inhibiting coating for metal comprises the following steps: i) diluting a surfactant in a certain amount of water on the metal to be coated, so that the surfactant gradually pours onto the surface of the metal; ii) adding a metal precursor to the said amount of water; iii) reducing the metal precursor so that it is deposited on the surface of the metal with the surfactant; iv) forming a nanostructured lattice of the surfactant and the reduced metal precursor on the surface of the metal; v) removing the surfactant by washing with water, thereby obtaining a coating of the reduced metal precursor having a mesoporous structure. This results in a nanostructured surface arrangement in the form of hexagonal (or substantially hexagonal) unit cells, which is specifically designed to inhibit oxygen reduction reactions and thus prevent corrosion on the metal to which it is applied.

[0013] Unexpectedly, the prior art proposes the use of metal nanostructures as catalysts in oxygen reduction reactions, a phenomenon that is completely opposite to that observed in the present invention.

[0014] It should be mentioned that there are generally two methods to reduce the precursor. One is a chemical method, in which the metal is subjected to direct exposure by contact with a liquid in which a reducing substance is present or with a gas formed by the reducing substance. Another method is an electrochemical method performed in a battery, in which at least two electrodes are arranged: a modified electrode, i.e., an electrode protected by a coating, and an auxiliary or "sacrificial" electrode, and it involves passing an electric current between the two. The applied electrical energy can be measured in amperes (as current), in volts (as voltage or potential), and in coulombs (as charge). Depending on the variable being controlled, there are different modes. When a controlled current is applied, the process is called constant current. When a controlled potential is applied, if it is a constant potential, the process is called constant potential, and if it is a variable potential, the process is called kinetic potential.

[0015] Note that in electrochemical processes, the amount of charge is related to the amount of material that may have been deposited, and therefore represents an approximate indication of the amount of reaction that has occurred, which is particularly useful in galvanostatic processes.

[0016] Furthermore, corrosion can be defined as an irreversible reaction between a material and its medium, resulting in the degradation of the material or its properties. Furthermore, depending on the corrosion mechanism, chemical corrosion (or dry corrosion) or electrochemical corrosion (or wet corrosion) can occur. In chemical corrosion, oxidation of the metal occurs at high temperatures in a gaseous atmosphere, producing a solid film of reaction products on the metal's surface. However, in electrochemical corrosion, or wet corrosion, the action of an electrochemical cell occurs, with the metal dissolving in the anodic region where oxidation occurs. Electrochemical corrosion occurs at moderate temperatures and in the presence of an electrolyte. This type of corrosion occurs at the interface between a material and an aqueous solution. Therefore, for corrosion to occur, both oxidation and reduction reactions must occur. Typically, oxidation of the metal produces soluble cations or forms metal oxides. Furthermore, when substances present in the solution are reduced, protons, water, or dissolved oxygen are produced.

[0017] The method described in the present invention allows coating and inhibiting corrosion on any metallic material. In a particular embodiment, the metal to be coated is selected from the group consisting of gold, platinum, copper, steel and nickel or mixtures thereof.

[0018] Preferably, the mesoporous structure obtained by the method described in the present invention comprises a plurality of pores with a diameter of about 2 nm to 50 nm, wherein it can be observed that the effect of suppressing the oxygen reduction reaction is thereby enhanced. This is because the surfactant modifies the surface geometry of the deposited material (i.e., the reduced metal precursor, preferably platinum) and simultaneously modifies the surface electronic structure, which suppresses the adsorption of molecular oxygen.

[0019] In a particular embodiment, the methods of the present invention utilize about 45% to 55% by weight of surfactant, wherein the wt% is the weight of the surfactant relative to the total weight of the formulation comprising all elements (ie, surfactant, metal precursor, and water).

[0020] Surfactants can be classified by their "HLB" (hydrophilic-lipophilic balance). Preferred surfactants of the present invention have an HLB of at least 10, and are preferably nonionic surfactants.

[0021] In a particular embodiment, the surfactant is a polyoxyethylene alkyl ether or comprises a polyoxyethylene alkyl ether (e.g., a surfactant known as a Brij surfactant), preferably present in an amount of about 45% to 55% by weight, wherein the weight percent is the weight of the surfactant in the total weight of the formulation comprising all elements (i.e., surfactant, metal precursor, and water). It has been experimentally observed that at these percentages, the components enable a mesoporous structure to be obtained in the coating of the reduced metal precursor.

[0022] Brij surfactants are polyoxyethylene fatty ethers derived from lauryl alcohol, cetyl alcohol, stearyl alcohol, and oleyl alcohol. Specific examples of Brij surfactants useful in the present invention include, but are not limited to, octaethylene glycol monocetyl ether, polyoxyethylene (10) cetyl ether or decaethylene glycol cetyl ether (Brij 56), polyoxyethylene (20) cetyl ether (Brij 58), polyoxyethylene (4) lauryl ether (Brij 30), and polyoxyethylene (23) lauryl ether (Brij 35), or mixtures thereof.

[0023] In a particular embodiment, the surfactant is or comprises about 45% to 55% by weight of octaethylene glycol monohexadecyl ether, wherein the weight percent is the weight of the surfactant relative to the total weight of the formulation comprising all elements (i.e., surfactant, metal precursor, and water). It has been experimentally observed that at these percentages, the components enable a mesoporous structure to be obtained in the coating of the reduced metal precursor.

[0024] In a particular embodiment, the surfactant is or comprises about 45% to 55% by weight of decaethylene glycol hexadecyl ether, wherein the weight % is the weight of the surfactant relative to the total weight of the formulation comprising all elements (i.e., surfactant, metal precursor, and water). It has been experimentally observed that at these percentages, the components enable a mesoporous structure to be obtained in the coating of the reduced metal precursor.

[0025] Examples of other surfactants that can be used in the present invention include, but are not limited to, nonionic surfactants, such as poly(alkylene oxide) block copolymers, such as poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) block copolymers, such as poloxamers and poloxamines (commonly known by the names Pluronic and Tetronic, respectively), such as poloxamer 188 (Pluronic F-68), poloxamer 407 (Pluronic F-127), and the like; nonylphenol ethoxylates, such as the Tergitol NP series (Tergitol NP-9, and the like); octoxyls, which can vary in the number of repeating ethoxy(oxy-1,2-ethanediyl) groups, such as octoxyl-9 (Triton X-10). X-100); polyoxyethylene sorbitan esters (commonly known as Tweens), such as polysorbate 20 and polysorbate 80; sorbitan esters (commonly known as Spans), such as sorbitan trioleate (Span 85) and sorbitan monolaurate; or mixtures thereof.

[0026] In another specific embodiment, the metal precursor is or comprises about 5% to 20% by weight of a metal salt, wherein the wt% is likewise the weight of the metal precursor in the total weight of the formulation comprising the surfactant as well as the metal precursor and water.

[0027] In another specific embodiment, the metal precursor is or comprises from about 5% to 20% by weight of aqueous hexachloroplatinic acid, wherein the weight percent is likewise the weight of the metal precursor relative to the total weight of the formulation comprising the surfactant, the metal precursor, and water. It has been experimentally observed that at these percentages, the components allow for a highly effective corrosion-inhibiting coating.

[0028] In another particular embodiment, the metal precursor is or comprises from about 5% to 20% by weight of nickel chloride, wherein the weight percent is likewise the weight of the metal precursor relative to the total weight of the formulation comprising the surfactant, the metal precursor, and water. Experimental observations have shown that at these percentages, the components allow for a highly effective corrosion-inhibiting coating.

[0029] In another specific embodiment, the metal precursor is or comprises from about 5% to 20% by weight of chloroauric acid, wherein the weight percent is likewise the weight of the metal precursor relative to the total weight of the formulation comprising the surfactant, the metal precursor, and water. It has been experimentally observed that at these percentages, the components make it possible to obtain a corrosion-inhibiting coating with high efficacy.

[0030] Examples of other metal precursors that can be used in the present invention include, but are not limited to, salts of all elements in the periodic table that can crystallize in a face-centered cubic crystal structure. These include iron, aluminum, copper, zinc, tin, nickel, lead, silver, gold, platinum, ruthenium, lanthanum, cobalt, rhodium, iridium, palladium, praseodymium, neodymium, etc., or mixtures thereof.

[0031] Additionally, in a particular embodiment, the reduced metal precursor is one from the group of platinum, ruthenium, gold, iron, nickel, cobalt, copper, zinc, tin and lead, or a mixture thereof, wherein the elements of the periodic table are those that have been shown to be most effective in obtaining corrosion-inhibiting coatings.

[0032] More specifically and with respect to the chemical method, step iii) of the manufacturing method comprises exposing the metal precursor to a reducing agent, such that the metal precursor is reduced and the reduced metal precursor is deposited on the surface of the metal with the surfactant, so that a layer or film of the corrosion-inhibiting coating is formed. It should be noted that the corrosion-inhibiting coating can be obtained by exposure to the reducing agent in liquid form or in the form of a gas or vapor.

[0033] In a preferred embodiment of the present invention, the reducing agent is one from the group of lithium aluminum hydride, sodium borohydride and hydrazine, which have been experimentally observed to be highly effective in obtaining reduced metal precursors.

[0034] Furthermore, and with respect to the electrochemical method for producing the inhibitory coating, step iii) comprises applying electrical energy to the dilute solution having the metal precursor so that the metal precursor is reduced and deposited on the surface of the metal having the surfactant. The application time may typically range from 1.0×10 -6 sec to 86400 sec, and the scan rate range is approximately 1.0×10 -4 V / s to 5.0 V / s.

[0035] It should be mentioned that, regarding the potentiostatic electrochemical method, applying electrical energy to the dilute solution with the metal precursor is preferably by applying a constant voltage of about -5 V to 1 V. From this, it was experimentally observed that good performance in terms of reduction of the metal precursor was achieved.

[0036] Furthermore, with respect to the potentiodynamic electrochemical method, it should be noted that applying electrical energy to the dilute solution with the metal precursor is preferably by applying a variable voltage of about -5 V to 1 V. It was also experimentally observed that good performance in the reduction of the metal precursor was achieved.

[0037] Furthermore, it should be added that, with regard to the galvanostatic electrochemical method, ie, the current is measured, electrical energy is applied to the dilute solution containing the metal precursor, preferably by applying approximately 1.0×10 -6 A current of -10 A was observed from this experiment to achieve good performance in the reduction of the metal precursor.

[0038] Furthermore, with respect to galvanostatic electrochemical methods, which measure current (in this case, charge), it is noted that applying electrical energy to the dilution solution with the metal precursor is preferably accomplished by applying approximately 0.01 C x cm -2 to 1C×cm -2 From this experiment it was observed that good performance in the reduction of the metal precursor was achieved. It should be noted that the charge applied will depend on the specific metal precursor and the desired coating thickness.

[0039] According to the present invention, at least one of steps i) to v) is preferably carried out at a controlled temperature of about 55 to 65°C, in which range it was found that better performance in obtaining a corrosion inhibiting coating is achieved.

[0040] Another object of the present invention relates to a corrosion-inhibiting coating for metals produced or obtainable according to the method described in detail above, and to the use of said coating as a corrosion-inhibiting coating for metals. More particularly, the use of the coating of the present invention as an anti-corrosion coating for metals is based on its unexpected ability to inhibit, minimize, or delay oxygen reduction reactions.

[0041] All features described in this specification (including claims, description and drawings) may be combined in any combination, except such mutually exclusive combinations of features and / or steps. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] These and other features and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments thereof, given by way of illustrative and non-limiting example only with reference to the accompanying drawings.

[0043] Figure 1 A schematic diagram illustrating a chemical process for producing a corrosion inhibiting coating according to one embodiment of the present invention;

[0044] Figure 2 shows a schematic diagram of an electrochemical method for producing a corrosion-inhibiting coating according to one embodiment of the present invention;

[0045] Figure 3 An illustrative view showing a diagram of corrosion phenomena;

[0046] Figure 4 Illustrative views of cyclic voltammograms of the mesoporous structure of platinum MP-Pt (top; according to an embodiment of the present invention) and Pt lines (bottom; comparison) are shown, where the metal precursors used to produce MP-Pt are hexachloroplatinic acid in 0.5 M H2SO4 (left) and 0.1 M NaOH (right), and in the case of MP-Pt, octaethylene glycol monohexadecyl ether is used in the absence of O2 (solid line) and in the presence of O2 (dashed line). DETAILED DESCRIPTION

[0047] With reference to the drawings mentioned, and according to the reference numbers used, a preferred embodiment of the invention can be seen therein, comprising the parts and elements indicated and described in detail below.

[0048] exist Figure 1 A schematic diagram of the chemical process for producing a corrosion-inhibiting coating (3) can be seen in Figure 1. A metal (1) can be seen whose surface (2) is to be protected by a coating (3) having a lattice (31) with a mesoporous structure (32). The surfactant (4) remains in the corresponding pores (32a) and is ultimately removed using a water bath (7). The metal precursor (5) is reduced using a reducing agent (6).

[0049] exist Figure 2 A schematic diagram of the electrochemical method for producing a corrosion-inhibiting coating (3) can be seen. A metal (1) can also be seen, the surface (2) of which is to be protected by a coating (3) having a lattice (31) with a mesoporous structure (32). Similarly, the surfactant (4) resides in the corresponding pores (32a) and is finally removed using a water bath (7), and the metal precursor (5) is reduced using a reducing agent (6). Furthermore, a device for applying electrical energy (8) can be seen, which is in the form of one of a voltage (81), a current (82) or an electrical charge (83), depending on the type of method applied.

[0050] Figure 4 A preferred embodiment of the present invention is shown, wherein the electrocatalytic activity of a gold electrode having a platinum (Pt) coating is induced by an electrochemical reduction method to obtain a mesoporous structure (32) having a nanostructure and a specific surface arrangement to suppress the oxygen reduction reaction.

[0051] First, the synthesis step is preferably carried out by electrochemical reduction of a mixture of aqueous hexachloroplatinic acid (8%) and 50% by weight of octaethylene glycol monohexadecyl ether (C16EO8) on a Au disk electrode (φ=7 mm) at 60° C. and 0.15 relative to RHE. The result corresponds to an electrode obtained after a charge of 272 mC has passed during the deposition. Finally, the electrode is kept in distilled water (7) for 48 hours, with the liquid being changed every 2 hours. This synthesis allows platinum (Pt) to be deposited from solution onto the surface (2) of the gold electrode, producing a platinum (Pt) coating (3) having a mesoporous structure (32) characterized by the presence of pores (32a) with a diameter ranging from 2 nm to 50 nm.

[0052] exist Figure 3 In the diagram, an illustrative view of the corrosion phenomenon on the surface (2) of the metal (1) can be observed. The corrosion is located in the anodic region of the metal (1), where oxidation occurs, while the reduction of the medium occurs in the cathodic region. Since an electrochemical circuit is established, electrons circulate through the metal from the anode to the cathode, and the circuit is closed by the electrolyte (in which ions circulate).

[0053] However, if the metal surface is protected with the coating proposed in the present invention, the interaction with molecular oxygen is avoided, thus suppressing the reduction reaction (necessary for the existence of oxidation) and thus preventing corrosion of the material.

[0054] From a thermodynamic point of view, the corrosion process is measured by the Gibbs free energy (ΔG). The more negative this value is (ΔG < 0), the greater the tendency of the reaction to proceed. The value of ΔG is related to the electromotive force (emf) or potential (E) of the corrosion cell according to the ratio ΔG = -n·F·E, where "n" is the number of electrons exchanged and F is the Faraday constant (96500 coulombs / chemical equivalent). Therefore, the larger the value of E, the greater the tendency of the cell to corrode, but it should be noted that although thermodynamics indicates that corrosion reactions may occur, they may or may not occur due to the formation of a protective film or passivation film that delays the reaction kinetics.

[0055] In order to avoid corrosion, nanoparticles can be used as a coating material (3), which acts as a barrier to control the corrosion rate. The present invention focuses on inhibiting the reduction of molecular oxygen, which acts as a cathode reaction and is the most common (20% of air is composed of molecular oxygen) and important in the corrosion process. For this purpose, a specific surface atomic metal structure or mesoporous structure (32) is developed on the metal (1) to be protected. In addition, platinum (Pt) is preferably used for the mesoporous structure (32) because the inventors observed that it is unexpectedly the material that shows the highest efficiency for the oxygen reduction reaction on the polycrystalline gold (Au) surface (2).

[0056] It is important to emphasize that the kinetics and mechanism of the oxygen reduction reaction (ORR) have been extensively studied in the prior art for many catalytic materials, with platinum being the best electrocatalyst because it allows the reduction of O2 to four electrons at a relatively low overpotential. Therefore, the results obtained in the present invention with a coating of electrocatalytic material are completely unexpected and show that the electrocatalytic activity towards ORR can be suppressed even for the material that currently exhibits the highest catalytic activity: platinum.

[0057] exist Figure 4 An illustrative view of the cyclic voltammogram associated with the metal precursor (5) (hexachloroplatinic acid) and the surfactant (4) (octaethylene glycol monohexadecyl ether) can be observed. Specifically, experiments were conducted on platinum (Pt) mesoporous structures (32) and on polycrystalline platinum (Pt) wires in the absence and presence of molecular oxygen over a wide pH range.

[0058] More specifically, it should be noted that in order to study the electrocatalytic activity of the electrode having a platinum (Pt) mesoporous structure (32) for the oxygen reduction reaction, a three-electrode cell was used, which used a reversible hydrogen electrode (RHE) as a reference and a glassy carbon counter electrode. An Au electrode having a platinum (Pt) mesoporous coating (3) was used as a working electrode. Figure 4 The performance of the synthesized electrodes for the oxygen reduction reaction (ORR) is shown using sulfuric acid or sodium hydroxide as the background electrolyte via the primary cathodic half-reaction in an aerated aqueous medium. The behavior in the presence or absence of oxygen indicates no electrolytic activity for O2 reduction, as no increase in cathodic current was observed during the experiments in the presence of oxygen.

[0059] For comparative purposes, the electrocatalytic activity of unmodified platinum (Pt) wires in the absence and presence of oxygen in sulfuric acid or sodium hydroxide as background electrolyte was investigated. Figure 4 It can be observed that in the presence of oxygen, a cathode current corresponding to oxygen reduction appears in the case of the platinum (Pt) wire due to its high electrocatalytic activity for oxygen reduction reaction.

[0060] Finally, the embodiments described herein have experimentally demonstrated that the composite material (ie, the coated metal) is not electroactive towards the oxygen reduction reaction over a wide pH range, which has significant implications in the field of corrosion.

[0061] In addition, by applying the method described above for depositing platinum on gold, but varying the metal precursor and / or polycrystalline metal to be coated, the following mesoporous coatings were produced: platinum on platinum, platinum on copper, platinum on stainless steel, platinum on nickel, gold on gold, and nickel on nickel. The metal precursors used for platinum deposition in these examples were aqueous hexachloroplatinic acid (8%), 1.8 M nickel chloride (NiCl2) for nickel, and 0.2 M chloroauric acid H [AuCl4] for gold. In all of these examples, the presence of a reduced metal precursor with a mesoporous structure was observed, and corrosion was suppressed.

[0062] More specifically, if Figure 1 and Figure 2 As observed in , a method for producing a corrosion inhibiting coating (3) for a metal (1) comprises the following steps: i) diluting a surfactant (4) in a certain amount of water (7) on the metal (1) to be coated so that the surfactant (4) is gradually poured onto the surface (2) of the metal (1); ii) adding a metal precursor (5) to the said amount of water (7); iii) reducing the metal precursor (5) so that it is deposited on the surface (2) of the metal (1) having the surfactant (4); iv) forming a nanostructured lattice (31) of the surfactant (4) and the reduced metal precursor (5) on the surface (2) of the metal (1); v) removing the surfactant (4) from the surface (2) of the metal (1) by washing with water (7), thereby obtaining a coating (3) of the reduced metal precursor (5) having a mesoporous structure (32). It should be noted that in this preferred embodiment, washing with water (7) comprises keeping in distilled water (7) for 48 hours, changing the liquid every 2 hours.

[0063] Preferably, if Figure 1 and Figure 2 As observed in FIG, the mesoporous structure (32) includes a plurality of pores (32a) with diameters ranging from about 2 nm to 50 nm.

[0064] In more detail, Figure 1 and Figure 2 As observed in the , surfactant (4) is about 45 to 55 weight percent octaethylene glycol monohexadecyl ether, with the preferred and optimal value being about 50 weight percent.

[0065] In addition, if Figure 1 and Figure 2 As observed in , the metal precursor (5) is about 5 wt% to 20 wt% aqueous hexachloroplatinic acid, with the preferred and optimal value being about 8 wt%.

[0066] According to another aspect of the present invention, Figure 1 and Figure 2As observed in , the reduced metal precursor (5) is one from the group of platinum, ruthenium, gold, iron, nickel, cobalt, copper, zinc, tin and lead or a mixture thereof, wherein the preferred reduced metal precursor is platinum.

[0067] Optionally, as Figure 1 As observed in , the method for the chemical production of a corrosion inhibiting coating (3) for a metal (1) is characterized in that step iii) comprises exposing a metal precursor (5) to a reducing agent (6) so that the metal precursor (5) is reduced and the reduced metal precursor (5) is deposited on the surface (2) of the metal (1) with the surfactant (4).

[0068] In addition, Figure 1 As observed in the above, the reducing agent (6) is one or a mixture thereof from the group consisting of lithium aluminum hydride, sodium borohydride and hydrazine.

[0069] Or, as Figure 2 As observed in , the method for the electrochemical production of a corrosion inhibiting coating (3) on a metal (1) is characterized in that step iii) comprises applying electrical energy (8) to a dilute solution with a metal precursor (5), so that the metal precursor (5) is reduced and deposited on the surface (2) of the metal (1) with the surfactant (4).

[0070] Optionally, as Figure 2 As observed in FIG, applying electrical energy (8) to the dilute solution with the metal precursor (5) is performed by applying a constant voltage (81) of about -5 volts to 1 volt.

[0071] Optionally, as Figure 2 As observed in FIG, applying electrical energy (8) to the dilute solution with the metal precursor (5) is performed by applying a variable voltage (81) ranging from about -5 volts to 1 volt.

[0072] Optionally, as Figure 2 observed that by applying about 1.0×10 -6 Applying electrical energy (8) to the diluted solution having the metal precursor (5) is performed by applying a current (82) of 100 amperes to -10 amperes.

[0073] Optionally, as Figure 2 observed in the , by applying about 0.01C×cm -2 to 1C×cm -2 The electric energy (8) is applied to the dilute solution containing the metal precursor (5) by means of an electric charge (83).

[0074] In addition, if Figure 1 and Figure 2 As observed in , at least one of steps i) to v) is performed at a controlled temperature of about 55°C to 65°C, preferably at a temperature of about 60°C.

[0075] In addition, if Figure 1 and Figure 2 As observed in , one object of the present invention relates to a corrosion inhibiting coating (3) for a metal (1) manufactured according to the above method.

[0076] Finally, if Figure 1 and Figure 2 As observed in , the present invention also comprises the use of a metal (1) with a corrosion inhibiting coating (3).

[0077] The details, forms, dimensions and other accessory elements and parts used in the implementation of the method for producing a corrosion inhibiting coating (3) for metal (1) may be replaced as appropriate by other items that are technically equivalent and do not depart from the essence of the invention or from the scope defined by the claims included after the following list.

[0078] As used herein, the term "about" or "approximately" when applied to one or more values of interest refers to a value that is similar to the indicated reference value. In certain forms, the term "about" or "approximately" as used herein means that the number can vary by up to ±20%, preferably within ±10%, and more preferably within ±5%. When "about" is used before a range, it applies to both the upper and lower limits of the range.

[0079] In fact, those skilled in the art know that the numerical value associated with measurement is affected by the measurement error that limits its precision. When the term such as "about" or "approximately" is applied to a specific value (e.g., "about 200°C" or "about 200°C") or range (e.g., "about x to about y"), the value or range can be interpreted as being only as accurate as the method used to measure it. Unless otherwise specifically stated, the general convention in scientific and technical literature can be applied so that the last digit of the numerical value preferentially represents the precision of the measurement. Therefore, unless other error ranges are given, the maximum range can be determined by applying the convention of rounding to the last decimal place. For example, the value 3.5 preferably has an error range of 3.45 to 3.54, and the range of 2% to 10% preferably covers the range of 1.5% to 10.4%. The described variation of the specified value is understood by those skilled in the art and within the context of the present invention. In addition, in order to provide a more concise description, some of the quantitative expressions given herein are not limited by the term "about". It should be understood that every quantity given herein, whether or not the term "about" is expressly used, is intended to refer to the actual given value, and is also intended to refer to the approximate value that one of ordinary skill in the art would reasonably infer based on the given value, including equivalent values and approximate values due to the experimental and / or measurement conditions of the given value.

[0080] Concentration, amount and other numerical data can be represented or presented in range format in this article.It should be understood that the range format is used only for convenience and simplicity, and therefore should be flexibly interpreted to include not only the numerical value clearly listed as the limit of range, but also include all single numerical values or subranges encompassed within the range, as if each numerical value and subrange are clearly listed.As an illustration, the numerical range of "about 1 wt % to about 5 wt %" should be interpreted as not only including the value of about 1 wt % to about 5 wt % clearly listed, but also including single values and subranges within the specified range.Therefore, this numerical range includes single values such as 2,3 and 4, and subranges such as 1 to 3, 2 to 4 and 3 to 5 etc. The same principle applies to the scope of mentioning a single numerical value.

[0081] Description of reference numerals:

[0082] 1 Metal

[0083] 2 Surface

[0084] 3 coating

[0085] 31 dot matrix

[0086] 32 mesoporous structure

[0087] 32a hole

[0088] 4 Surfactants

[0089] 5 Metal Precursors

[0090] 6 reducing agent

[0091] 7. Water

[0092] 8. Electricity

[0093] 81 voltage

[0094] 82 current

[0095] 83 charge

Claims

1. A method for producing a corrosion-inhibiting coating (3) for a metal (1), comprising the following steps: i) diluting a surfactant (4) in a certain amount of water (7) on the metal (1) to be coated, so that the surfactant (4) is gradually poured onto the surface (2) of the metal (1); ii) adding a metal precursor (5) to the amount of water (7); iii) reducing the metal precursor (5) so that it is deposited on the surface (2) of the metal (1) having the surfactant (4); iv) forming a nanostructured lattice (31) of a surfactant (4) and a reduced metal precursor (5) on the surface (2) of the metal (1); v) removing the surfactant (4) from the surface (2) of the metal (1) by washing with water (7), thereby obtaining a coating (3) of reduced metal precursor (5) having a mesoporous structure (32).

2. The method for producing a corrosion-inhibiting coating (3) for metal (1) according to claim 1, characterized in that the mesoporous structure (32) comprises a plurality of pores (32a) having a diameter of about 2 nm to 50 nm.

3. A method for producing a corrosion-inhibiting coating (3) for metal (1) according to any of the preceding claims, characterized in that the surfactant (4) is a nonionic surfactant, preferably a polyoxyethylene alkyl ether, more preferably about 45% to 55% by weight of octaethylene glycol monohexadecyl ether and / or decaethylene glycol hexadecyl ether.

4. The method for producing a corrosion-inhibiting coating (3) for metals (1) according to any one of the preceding claims, characterized in that the metal precursor (5) is about 5% to 20% by weight of aqueous hexachloroplatinic acid, nickel chloride and / or chloroauric acid.

5. The method for producing a corrosion-inhibiting coating (3) for a metal (1) according to any one of claims 1 to 3, characterized in that the reduced metal precursor (5) is one from the group of platinum, ruthenium, gold, iron, nickel, cobalt, copper, zinc, tin and lead, or any mixture thereof.

6. A method for producing a corrosion-inhibiting coating (3) for a metal (1) according to any one of the preceding claims, characterized in that step iii) comprises exposing the metal precursor (5) to a reducing agent (6) such that the metal precursor (5) is reduced and the reduced metal precursor (5) is deposited on the surface (2) of the metal (1) having the surfactant (4).

7. The method for producing a corrosion-inhibiting coating (3) for metals (1) according to claim 6, characterized in that the reducing agent (6) is one from the group of lithium aluminum hydride, sodium borohydride and hydrazine.

8. A method for producing a corrosion-inhibiting coating (3) for a metal (1) according to any one of claims 1 to 5, characterized in that step iii) comprises applying electrical energy (8) to a dilution solution having a metal precursor (5) so that the metal precursor (5) is reduced and deposited on the surface (2) of the metal (1) having the surfactant (4).

9. The method for producing a corrosion-inhibiting coating (3) for metal (1) according to claim 8, characterized in that applying electrical energy (8) to the diluted solution with the metal precursor (5) is performed by applying a constant voltage (81) of -5 volts to 1 volt.

10. The method for producing a corrosion-inhibiting coating (3) for metal (1) according to claim 8, characterized in that applying electrical energy (8) to the diluted solution with the metal precursor (5) is performed by applying a variable voltage (81) of -5 volts to 1 volt.

11. The method for producing a corrosion-inhibiting coating (3) for metal (1) according to claim 8, characterized in that by applying 1.0×10 -6 Applying electrical energy (8) to the diluted solution having the metal precursor (5) is performed by applying a current (82) of 100 amperes to -10 amperes.

12. The method for producing a corrosion-inhibiting coating (3) for metal (1) according to claim 8, characterized in that the coating is formed by applying 0.01 C x cm -2 to 1C×cm -2 The electric energy (8) is applied to the dilute solution containing the metal precursor (5) by means of an electric charge (83).

13. Method for producing a corrosion-inhibiting coating (3) for metal (1) according to any one of the preceding claims, characterized in that at least one of steps i) to v) is carried out at a controlled temperature of about 55 to 65°C.

14. A corrosion-inhibiting coating (3) for metal (1) obtainable by the method according to any one of claims 1 to 13.

15. Use of the coating (3) according to claim 14 as a corrosion-inhibiting coating for metals (1).

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