Protective coating as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of protective coatings, and provides a protective coating as well as a preparation method and application thereof. The organic-functional material layer is introduced between the induction layer and the mineralization layer. On one hand, the functional material is embedded into the induction layer through chemical bonding and interface action, the specific surface area of the surface is increased, more active sites are provided for growth of inorganic crystals in the mineralization layer, then the compactness of the mineralization layer is improved, and the mechanical performance of the protective coating is enhanced. On the other hand, when the functional material is a two-dimensional lamellar material, a compact barrier layer is constructed to isolate permeation of corrosive ions such as Cl <-> and SO4 < 2->, so that the chloride ion diffusion resistance coefficient is reduced, the corrosion induction period of the matrix is prolonged, and the corrosion resistance of the protective coating is improved; in addition, the functional material can endow the protective coating with functionality by grafting and loading a functional reagent, and particularly, the long-term effect of the anti-corrosion function of the protective coating can be improved by grafting and loading an anti-corrosion component on the functional material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of protective coating, in particular to a protective coating and a preparation method and application thereof. BACKGROUND

[0002] With the acceleration of urbanization and the complexity of engineering service environment, traditional concrete materials are facing multiple performance challenges: in the field of traffic engineering, the high-frequency load of highways and heavy railroads leads to an increasing surface wear rate of concrete materials year by year. In marine engineering, the structural failure of concrete materials caused by chloride ion erosion accounts for an increasing proportion year by year.

[0003] The existing surface protection technology of concrete materials mainly includes inorganic coating, polymer coating, metal plating and biomimetic polymer composite inorganic coating. Since the biomimetic polymer composite inorganic coating has the advantages of both polymer coating and inorganic coating, it is widely used. The existing biomimetic polymer composite inorganic coating has excellent toughness and strength, but the strength needs to be further improved. SUMMARY

[0004] Therefore, the present application aims to provide a protective coating and a preparation method and application thereof. The protective coating provided by the present application has high mechanical strength.

[0005] In order to achieve the above-mentioned application purposes, the present application provides the following technical solutions:

[0006] The present application provides a protective coating, which comprises an induction layer, an organic-functional material layer and a mineralization layer which are sequentially stacked on a substrate.

[0007] The functional material in the organic-functional material layer is a two-dimensional sheet material and / or a particulate material.

[0008] The mineralization layer is made of calcium phosphate or calcium carbonate.

[0009] Preferably, a base layer is arranged between the induction layer and the organic-functional material layer, and the base layer is made of calcium phosphate or calcium carbonate.

[0010] Preferably, the induction layer, the organic-functional material layer and the mineralization layer are periodically arranged.

[0011] The present application also provides a preparation method of the protective coating described in the above technical solutions, which comprises the following steps:

[0012] An induction layer is prepared on a substrate to obtain a substrate / induction layer.

[0013] An organic-functional material layer is prepared on the induction layer of the substrate / induction layer to obtain a substrate / induction layer / organic-functional material layer.

[0014] preparing a mineralized layer on the organic-functional material layer of the substrate / induction layer / organic-functional material layer, to obtain the protective coating;

[0015] The preparation of the mineralized layer comprises the following steps: placing the substrate / induction layer / organic-functional material layer into a third precursor solution, and then adding a fourth precursor solution dropwise; the third precursor solution comprises a calcium salt, an ion-dragging agent, and a crystal form regulator; the fourth precursor solution comprises carbonate or phosphate.

[0016] Preferably, the preparation of the induction layer comprises the following steps: applying an induction agent solution on the substrate; the induction agent in the induction agent solution is an organic substance containing amino groups and / or hydroxyl groups; the organic substance containing amino groups and / or hydroxyl groups is a polymer or a bio-based material;

[0017] The polymer comprises one or more of an epoxy resin, a polyurethane, a polylactic acid, a polyvinyl alcohol, a polyethylene glycol, a polylysine, a polyimide, a polybenzimidazole, a polyacrylamide, a polyethylene imine, a polyhydroxyalkanoate, a polybutylene succinate, a polyethylene furanoate, and an amphiphilic block copolymer comprising polyvinyl alcohol-polyacrylic acid;

[0018] The bio-based material comprises one or more of chitosan, a chitosan derivative, starch, a starch derivative, cellulose, a cellulose derivative, sodium alginate, collagen, silk fibroin, gelatin, and chitin;

[0019] The mass concentration of the induction agent solution is 0.25-1.5%.

[0020] Preferably, when the base layer is arranged between the induction layer and the organic-functional material layer, the method further comprises: preparing a base layer on the induction layer of the substrate / induction layer; the preparation of the base layer comprises the following steps: placing the substrate / induction layer into a first precursor solution, and then adding a second precursor solution dropwise; the first precursor solution comprises a calcium salt and an ion-dragging agent, and the ion-dragging agent comprises one or more of oxalic acid, malonic acid, succinic acid, adipic acid, lactic acid, malic acid, tartaric acid, citric acid, salicylic acid, glycine, alanine, glutamic acid, benzoic acid, sodium acetate, sodium citrate, aspartic acid, phthalic acid, p-aminobenzoic acid, polyacrylic acid, polymethacrylic acid, and sodium polyacrylate; the second precursor solution comprises carbonate or phosphate.

[0021] The calcium salt in the first precursor solution includes one or more of calcium chloride, calcium nitrate, calcium acetate, calcium bromide, calcium iodide, calcium formate, calcium propionate, calcium butyrate, calcium lactate, calcium sulfate, calcium chlorate, calcium chlorite, calcium perchlorate, calcium thiocyanate, calcium glycerophosphate, calcium dihydrogen phosphate, calcium gluconate, and calcium hyposulfite, and the mass concentration of the calcium salt is 0.25-1.5%; the mass concentration of the ion-dragging agent is 1.25×10 -3 ~2.25×10 -3 %;

[0022] The carbonate in the second precursor solution is provided by one or more of lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, cesium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, rubidium bicarbonate, cesium bicarbonate, ammonium bicarbonate, methylamine carbonate, calcium bicarbonate, magnesium bicarbonate, barium bicarbonate, zinc bicarbonate, iron bicarbonate, aluminum bicarbonate, ethylenediamine carbonate, dimethyl carbonate, and ethylene carbonate; the phosphate is provided by one or more of lithium phosphate, sodium phosphate, potassium phosphate, beryllium phosphate, calcium phosphate, trisodium phosphate, tripotassium phosphate, triammonium phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, calcium dihydrogen phosphate, ammonium dihydrogen phosphate, dipotassium hydrogen phosphate, disodium hydrogen phosphate, diammonium hydrogen phosphate, and triethyl phosphate; the mass concentration of the carbonate and the phosphate is independently 0.25-1.5%;

[0023] The second precursor solution is completed in 8-24 hours.

[0024] Preferably, the preparation of the organic-functional material layer comprises: applying an organic-functional material composite system on the induced layer of the substrate / induced layer;

[0025] The organic-functional material composite system comprises an inducing agent and a functional material;

[0026] The functional material is a two-dimensional sheet material and / or a particulate material;

[0027] The two-dimensional sheet material includes one or more of zirconium phosphate, intercalated zirconium phosphate, hydrotalcite compounds, hydrotalcite-like compounds, hexagonal boron nitride, graphene sheets, graphite intercalation compounds, graphene oxide, graphyne, graphite-phase carbon nitride, bismuth bromide, lead iodide, cadmium sulfide, indium selenide, bismuth telluride, niobium telluride, molybdenum disulfide, tungsten diselenide, tungsten ditelluride, niobium diselenide, titanium diselenide, molybdenum dioxide, vanadium dioxide, TMDs, MXenes, Xenes, two-dimensional MOFs, and two-dimensional COFs;

[0028] The particulate material includes one or more of calcium carbonate, silicon oxide, silicon carbide, silicon nitride, aluminum oxide, magnesium oxide, aluminum nitride, boron nitride, titanium diboride, corundum, pumice, zeolite, volcanic rock, sepiolite, polyethylene particles, polypropylene particles, activated carbon, and aerogel particles;

[0029] The mass concentration of the inducing agent in the organic-functional material composite system is 0.25-1.5%, and the mass concentration of the functional material is 0.05-0.75%.

[0030] Preferably, in the third precursor solution, the calcium salt includes one or more of calcium chloride, calcium nitrate, calcium acetate, calcium bromide, calcium iodide, calcium formate, calcium propionate, calcium butyrate, calcium lactate, calcium sulfate, calcium chlorate, calcium chlorite, calcium perchlorate, calcium thiocyanate, calcium glycerophosphate, calcium dihydrogen phosphate, calcium gluconate, and calcium hyposulfite, and the mass concentration of the calcium salt is 0.35-2.5%; the ionic drag agent includes one or more of oxalic acid, malonic acid, succinic acid, adipic acid, lactic acid, malic acid, tartaric acid, citric acid, salicylic acid, glycine, alanine, glutamic acid, benzoic acid, sodium acetate, sodium citrate, aspartic acid, phthalic acid, p-aminobenzoic acid, polyacrylic acid, polymethacrylic acid, and sodium polyacrylate, and the mass concentration of the ionic drag agent is 1.5x10 -3 ~2.5x10 -3 %; the crystal form regulator includes one or more of soluble salts, organic compound regulators, and biological molecule regulators; the soluble salts include one or more of magnesium chloride, strontium chloride, barium chloride, ammonium chloride, magnesium sulfate, aluminum sulfate, zinc sulfate, sodium sulfate, potassium sulfate, sodium carbonate, magnesium nitrate, strontium nitrate, barium nitrate, ammonium nitrate, sodium phosphate, and sodium tripolyphosphate; the organic compound regulators include one or more of ethylene glycol, glycerol, cetyltrimethylammonium bromide, sodium dodecyl sulfate, hydroxyethylidene diphosphonic acid, ethylenediaminetetramethylene phosphonic acid, glycerol, sorbitol, polyethylene glycol, polyvinyl alcohol, and polyvinylpyrrolidone; the biological molecule regulators include one or more of oxalic acid, glutamic acid, citric acid, malic acid, tartaric acid, succinic acid, glycine, aspartic acid, polysaccharide, casein, chitin, chitosan, heparin, carbonic anhydrase, lipase, and protease; and the mass concentration of the crystal form regulator is 0.04-0.14%;

[0031] In the fourth precursor solution, the carbonate is provided by one or more of lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, cesium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, rubidium bicarbonate, cesium bicarbonate, ammonium bicarbonate, methylamine carbonate, calcium bicarbonate, magnesium bicarbonate, barium bicarbonate, zinc bicarbonate, iron bicarbonate, aluminum bicarbonate, ethylenediamine carbonate, dimethyl carbonate, and ethylene carbonate; and the phosphate is provided by one or more of lithium phosphate, sodium phosphate, potassium phosphate, beryllium phosphate, calcium phosphate, trisodium phosphate, tripotassium phosphate, triammonium phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, calcium dihydrogen phosphate, ammonium dihydrogen phosphate, dipotassium hydrogen phosphate, disodium hydrogen phosphate, diammonium hydrogen phosphate, and triethyl phosphate.

[0032] The mass concentrations of the carbonate and phosphate groups are independently 0.35 to 2.5 wt %;

[0033] The fourth precursor solution is added dropwise within 12 to 24 hours.

[0034] Preferably, after preparing the mineralized layer, the method further includes repeating the process of sequentially preparing an induction layer, an organic-functional material layer and a mineralized layer on the mineralized layer.

[0035] The present invention also provides the use of the protective coating described in the above technical solution or the protective coating prepared by the preparation method described in the above technical solution in the protection of metal materials, ceramic materials, polymer materials and cement materials.

[0036] The present invention provides a protective coating.

[0037] (1) The introduction of functional materials in the organic-functional material layer achieves dual functions: On the one hand, the functional materials are embedded in the induction layer through chemical bonding and interfacial interaction, which increases the specific surface area of ​​the organic-functional material layer and provides more active sites for the growth of inorganic crystals in the mineralized layer, thereby improving the density of the mineralized layer and enhancing the mechanical properties of the protective coating. On the other hand, when the functional material is a two-dimensional sheet material, a dense barrier layer is constructed to isolate Cl - 、SO4 2- The penetration of corrosive ions such as chlorine ions reduces the diffusion coefficient of chloride ions, prolongs the rust induction period of the substrate, and improves the corrosion resistance of the protective coating. In addition, functional materials can also impart functionality to the protective coating by grafting functional reagents. In particular, by grafting anti-corrosion components on functional materials, the long-term corrosion resistance of the protective coating can be improved.

[0038] (2) In the present invention, the mineralized layer has the advantages of high hardness and good density, which can improve the wear resistance of the protective coating. The middle organic-functional material layer can block the migration of harmful substances, and the inner induction layer enhances the bonding strength with the substrate. This solves the problem of functional homogeneity of traditional coatings and can customize composite functions such as wear resistance, corrosion resistance, and bonding on demand. It meets the diverse needs of concrete surfaces for anti-scouring, weathering resistance, and multifunctional integration in scenarios such as bridges, nuclear power plants, and marine engineering, and promotes the upgrade of concrete from a single structural material to a functional composite system.

[0039] Furthermore, the present invention sets a base layer between the induction layer and the organic-functional material layer. The present invention induces the directional growth of inorganic crystals in the mineralized layer through the organic-functional material layer and the base layer, so that the mineralized layer is a denser and continuous mineralized layer. The denser and continuous mineralized layer can further improve the mechanical properties (such as strength and toughness), wear resistance, and impact damage resistance of the protective coating; and significantly improve the service stability of the substrate under high load environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 and Figure 2 SEM images of the organic-functional material layer in different magnifications of the substrate / induction layer / basement layer / organic-functional material layer;

[0041] Figure 3 SEM images of the mineralized layer in the protective coating;

[0042] Figure 4 Microhardness images of the concrete substrate (corresponding to the reference group in the figure) and the sample attached with the protective coating of Example 1 (corresponding to the mineralized group in the figure);

[0043] Figure 5 Microhardness images of the concrete substrate (corresponding to the reference group in the figure) and the sample attached with the protective coating of Example 2 (corresponding to the mineralized group in the figure);

[0044] Figure 6 Microhardness images of the concrete substrate (corresponding to the reference group in the figure) and the sample attached with the protective coating of Example 3 (corresponding to the mineralized group in the figure);

[0045] Figure 7 Microhardness images of the concrete substrate (corresponding to the reference group in the figure) and the sample attached with the protective coating of Example 4 (corresponding to the mineralized group in the figure);

[0046] Figure 8 Microhardness images of the concrete substrate (corresponding to the reference group in the figure) and the sample attached with the protective coating of Comparative Example 1 (corresponding to the mineralized group in the figure);

[0047] Figure 9 SEM images of the mineralized layer in different magnifications of the sample attached with the protective coating of Comparative Example 1;

[0048] Figure 10 SEM images of the mineralized layer in different magnifications of the sample attached with the protective coating of Comparative Example 2. DETAILED DESCRIPTION

[0049] The present application provides a protective coating, comprising an induction layer, an organic-functional material layer and a mineralized layer which are sequentially stacked on a substrate.

[0050] The protective coating provided by the present invention includes an induction layer stacked on a substrate. In the present invention, the substrate preferably includes one or more of a metal material, a ceramic material, a polymer material, and a cement material. In the present invention, the metal material preferably includes one or more of carbon steel, stainless steel, cast iron, tool steel, and a high-temperature alloy. In the present invention, the ceramic material preferably includes oxide ceramics or non-oxide ceramics. In the present invention, the polymer material includes polyethylene, polypropylene, or polystyrene. In the present invention, the cement material preferably includes cement paste, mortar, or concrete.

[0051] In the present invention, the material of the induction layer is preferably an organic substance containing amino groups and / or hydroxyl groups; the organic substance containing amino groups and / or hydroxyl groups is preferably a polymer or a bio-based material. In the present invention, the polymer preferably includes one or more of epoxy resin, polyurethane, polylactic acid, polyvinyl alcohol, polyethylene glycol, polylysine, polyimide, polybenzimidazole, polyacrylamide, polyethyleneimine, polyhydroxyalkanoate, polybutylene succinate, polyethylene furandicarboxylate, and amphiphilic block copolymers, and the amphiphilic block copolymer includes polyvinyl alcohol-polyacrylic acid. In the present invention, the bio-based material preferably includes one or more of chitosan, chitosan derivatives, starch, starch derivatives, cellulose, cellulose derivatives, sodium alginate, collagen, silk protein, gelatin, and chitin, and is more preferably chitosan. In the present invention, the thickness of the induction layer is preferably 5 to 100 nm.

[0052] The protective coating provided by the present application comprises an organic-functional material layer arranged on an induction layer. In the present application, the functional material in the organic-functional material layer is a two-dimensional sheet material and / or a particulate material; the two-dimensional sheet material preferably comprises one or more of zirconium phosphate, intercalated zirconium phosphate, hydrotalcite compound, hydrotalcite-like compound, hexagonal boron nitride, graphene sheet, graphite intercalation compound, graphene oxide, graphyne, graphite-phase carbon nitride, bismuth bromide, lead iodide, cadmium sulfide, indium selenide, bismuth telluride, niobium telluride, molybdenum disulfide, tungsten diselenide, tungsten ditelluride, niobium diselenide, titanium diselenide, molybdenum dioxide, vanadium dioxide, TMDs, MXenes, Xenes, two-dimensional MOFs and two-dimensional COFs, and is further preferably zirconium phosphate. In the present application, the two-dimensional sheet material is preferably surface-grafted with a functional agent, which preferably comprises but is not limited to one or more of corrosion inhibitors, rust inhibitors and lubricants, and the present application does not specifically limit the types and amounts of the corrosion inhibitors, rust inhibitors and lubricants, which can be of any type and in any amount as long as they are known to those skilled in the art and are needed. In the present application, the particulate material preferably comprises one or more of calcium carbonate, silicon oxide, silicon carbide, silicon nitride, aluminum oxide, magnesium oxide, aluminum nitride, boron nitride, titanium diboride, corundum, pumice, zeolite, volcanic rock, sepiolite, polyethylene particles, polypropylene particles, activated carbon and aerogel particles. In the present application, the particulate material is preferably surface-grafted with a functional agent, which is preferably of the same type and amount as described above, and will not be described here again. In the present application, the organic material in the organic-functional material layer is preferably an induction agent, which is preferably of the same type as the material of the induction layer, and will not be described here again. In the present application, the thickness of the organic-functional material layer is preferably 5-300 nm.

[0053] In the present application, a base layer is preferably arranged between the induction layer and the organic-functional material layer, and the material of the base layer is preferably calcium phosphate or calcium carbonate. In the present application, the thickness of the base layer is preferably 120-300 nm. In the present application, the base layer has the following functions: (1) After the base layer is arranged, nano-scale calcium carbonate or calcium phosphate particles will be formed on the surface, which will increase the surface roughness. At this time, the arrangement of the organic-functional material layer on the base layer will greatly increase the specific surface area of the surface, thereby providing more active sites for the growth of inorganic crystals in the mineralization layer. (2) The base layer grows in situ on the surface of the substrate through the induction layer, is well combined with the substrate, and has many active sites on the surface. The organic-functional material layer can be well combined with the base layer through chemical bonding and interfacial action, which not only improves the adhesion but also increases the nucleation sites of the subsequent mineralization layer.

[0054] The protective coating provided by the present application comprises a mineralized layer which is stacked on an organic-functional material layer. In the present application, the material of the mineralized layer is calcium phosphate or calcium carbonate. In the present application, the thickness of the mineralized layer is preferably 0.5-5 μm.

[0055] In the present application, the induction layer, the organic-functional material layer and the mineralized layer are preferably periodically arranged, specifically: induction layer, organic-functional material layer, mineralized layer, induction layer, organic-functional material layer, mineralized layer, …, which are stacked on the substrate in turn.

[0056] In the present application, when a base layer is arranged between the induction layer and the organic-functional material layer, the protective coating is specifically preferably: induction layer, base layer, organic-functional material layer, mineralized layer, induction layer, base layer, organic-functional material layer, mineralized layer, …, which are stacked on the substrate in turn.

[0057] The present application also provides a preparation method of the protective coating described in the above technical solution, comprising the following steps:

[0058] Preparation of the induction layer on the substrate to obtain the substrate / induction layer;

[0059] Preparation of the organic-functional material layer on the induction layer of the substrate / induction layer to obtain the substrate / induction layer / organic-functional material layer;

[0060] Preparation of the mineralized layer on the organic-functional material layer of the substrate / induction layer / organic-functional material layer to obtain the protective coating;

[0061] The preparation of the mineralized layer comprises the following steps: placing the substrate / induction layer / organic-functional material layer into a third precursor solution, and then adding a fourth precursor solution dropwise; the third precursor solution comprises a calcium salt, an ion-dragging agent and a crystal form adjusting agent; the fourth precursor solution comprises carbonate or phosphate.

[0062] Unless otherwise specified, the raw materials used in the present application are preferably commercially available products.

[0063] The present application prepares the induction layer on the substrate to obtain the substrate / induction layer.

[0064] In the present application, the type of the substrate is preferably consistent with the above technical solution, which will not be described here again.

[0065] Preferably, the present application further comprises a pretreatment of the substrate before the preparation of the induction layer. In the present application, when the substrate is a cement material, the pretreatment preferably comprises the following steps: polishing, ethanol washing, water washing and drying of the substrate in sequence; the ethanol washing is preferably performed under ultrasonic condition, and the ultrasonic time is preferably equal to or greater than 10 min, and further preferably 15-45 min. In the present application, the water washing is preferably performed by flushing, and the water used in the water washing is preferably deionized water. The present application does not specifically limit the parameters of the drying.

[0066] In the present application, the preparation of the induction layer preferably comprises the following step: applying an inducer solution on the substrate.

[0067] In the present application, the type of the inducer in the inducer solution is preferably consistent with the material of the induction layer described in the above technical solution, which is not described herein again.

[0068] In the present application, the mass concentration of the inducer solution is preferably 0.25-1.5%, and specifically preferably 0.25%, 0.5%, 0.75%, 0.8%, 1%, 1.2%, 1.25% or 1.5%. In the present application, the mass concentration of the inducer solution is 0.25-1.5%, and the inducer solution has good fluidity, which is conducive to attracting and chelating the reaction ions and polyelectrolytes in the solution.

[0069] In the present application, when the inducer is chitosan, the preparation method of the inducer solution preferably comprises the following step: stirring and mixing chitosan and an acetic acid solution (denoted as first stirring and mixing) to obtain the inducer solution. In the present application, the mass fraction of the acetic acid solution is preferably 1 wt%. In the present application, the first stirring and mixing time is preferably equal to or greater than 6 h, and further preferably 10-18 h, and specifically preferably 12 h.

[0070] In the present application, the application mode of the inducer solution is preferably spin coating, and the spin coating mode preferably comprises the following steps: performing first spin coating and second spin coating in sequence; the rotation speed of the first spin coating is preferably 800-1600 r / min, and further preferably 1000-1200 r / min; the time is preferably equal to or greater than 5 s, and further preferably 10-35 s; the rotation speed of the second spin coating is preferably 2500-5500 r / min, and further preferably 3500-4500 r / min; and the time is preferably equal to or greater than 15 s, and further preferably 35-60 s.

[0071] After obtaining the substrate / induction layer, the present application prepares an organic-functional material layer on the induction layer of the substrate / induction layer to obtain a substrate / induction layer / organic-functional material layer.

[0072] In the present invention, the preparation of the organic-functional material layer preferably includes: applying an organic-functional material composite system on the inductive layer of the substrate / inductive layer.

[0073] In the present invention, the organic-functional material composite system preferably includes an inducer and a functional material. In the present invention, the functional material is a two-dimensional sheet material and / or a granular material; the type of the two-dimensional sheet material is preferably consistent with the above-mentioned technical solution, which will not be repeated here. In the present invention, the two-dimensional sheet material is preferably a surface grafted functional agent, and the functional agent preferably includes but is not limited to one or more of corrosion inhibitors, rust inhibitors and lubricants. The present invention does not specifically limit the type of the corrosion inhibitor, rust inhibitor and lubricant and the amount of grafting. The reagent type familiar to those skilled in the art and the amount can be set as needed. In the present invention, the type of the granular material is preferably consistent with the above-mentioned technical solution, which will not be repeated here. In the present invention, the granular material is preferably a surface grafted functional agent, and the type and grafting amount of the functional agent are preferably consistent with the above-mentioned technical solution, which will not be repeated here.

[0074] In the present invention, in the organic-functional material composite system, the mass concentration of the inducer is preferably 0.25-1.5%, specifically preferably 0.25%, 0.5%, 0.75%, 0.8%, 1%, 1.2%, 1.25% or 1.5%; the mass concentration of the functional material is preferably 0.05-0.75%, specifically preferably 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7% or 0.75%.

[0075] In the present invention, the application method of the organic-functional material composite system is preferably spin coating, and the spin coating method preferably includes performing a third spin coating and a fourth spin coating in sequence. The rotation speed of the third spin coating is preferably 800-1600 r / min, and more preferably 1000-1200 r / min; the time is preferably greater than or equal to 10s, and more preferably 20-45s; the rotation speed of the fourth spin coating is preferably 2500-5500 r / min, and more preferably 3500-4500 r / min; the time is preferably greater than or equal to 15s, and more preferably 25-50s.

[0076] In the present application, the setting of the organic-functional material layer plays an inducing and regulating role in the growth of inorganic crystals in the subsequent mineralized layer. Specifically, on the one hand, the functional material is embedded in the inducing layer through chemical bonding and interfacial action, which increases the specific surface area of the organic-functional material layer and provides more active sites for the growth of inorganic crystals in the mineralized layer, providing a large number of nucleation sites for the growth of the subsequent mineralized layer, further improving the density of the mineralized layer, and ultimately improving the strength of the protective coating. On the other hand, when the functional material is a two-dimensional sheet material, a dense barrier layer is constructed to prevent the penetration of Cl - 、SO4 2- and other corrosive ions, reducing the chloride ion diffusion coefficient, prolonging the rust induction period of the substrate, and improving the corrosion resistance of the protective coating. In addition, the functional material can also load functional reagents through grafting, giving the protective coating functionality. In particular, by grafting corrosion-resistant components onto the functional material, the long-term corrosion resistance of the protective coating can be improved. Furthermore, the introduction of an organic-functional material layer between the inducing layer and the mineralized layer can increase the compatibility between the interfaces and improve the toughness of the protective coating.

[0077] After obtaining the substrate / inducing layer / organic-functional material layer, the present application prepares a mineralized layer on the organic-functional material layer of the substrate / inducing layer / organic-functional material layer to obtain the protective coating.

[0078] In the present application, the preparation of the mineralized layer includes the following steps: placing the substrate / inducing layer / organic-functional material layer into a third precursor solution, and then adding a fourth precursor solution dropwise.

[0079] In the present application, the third precursor solution includes a calcium salt, an ion-dragging agent, and a crystal form regulator. In the present application, the solvent of the third precursor solution preferably includes water.

[0080] In the present application, the calcium salt in the third precursor solution preferably includes one or more of calcium chloride, calcium nitrate, calcium acetate, calcium bromide, calcium iodide, calcium formate, calcium propionate, calcium butyrate, calcium lactate, calcium sulfate, calcium chlorate, calcium chlorite, calcium perchlorate, calcium thiocyanate, calcium glycerophosphate, calcium dihydrogen phosphate, calcium gluconate, and calcium hyposulfite, and the mass concentration of the calcium salt is preferably 0.35-2.5%, and more preferably 0.35%, 0.5%, 0.75%, 1%, 1.25%, 1.5%, 1.75%, 2%, 2.25%, or 2.5%.

[0081] In the present application, the ion-dragging agent in the third precursor solution preferably comprises one or more of oxalic acid, malonic acid, succinic acid, adipic acid, lactic acid, malic acid, tartaric acid, citric acid, salicylic acid, glycine, alanine, glutamic acid, benzoic acid, sodium acetate, sodium citrate, aspartic acid, phthalic acid, p-aminobenzoic acid, polyacrylic acid, polymethacrylic acid, and sodium polyacrylate, and the mass concentration of the ion-dragging agent is preferably 1.5 x 10 -3 ~ 2.5 x 10 -3 %, and particularly preferably 1.5 x 10 -3 %, 1.75 x 10 -3 %, 2 x 10 -3 %, 2.25 x 10 -3 %, or 2.5 x 10 -3 %.

[0082] In the present application, the crystal form regulator in the third precursor solution preferably comprises one or more of soluble salts, organic compound regulators, and biological molecule type regulators, and is further preferably a soluble salt; the soluble salt preferably comprises one or more of magnesium chloride, strontium chloride, barium chloride, ammonium chloride, magnesium sulfate, aluminum sulfate, zinc sulfate, sodium sulfate, potassium sulfate, sodium carbonate, magnesium nitrate, strontium nitrate, barium nitrate, ammonium nitrate, sodium phosphate, and sodium tripolyphosphate; the organic compound regulator preferably comprises one or more of ethylene glycol, glycerol, cetyltrimethylammonium bromide, sodium dodecyl sulfate, hydroxyethylidene diphosphonic acid, ethylenediaminetetramethylene phosphonic acid, glycerol, sorbitol, polyethylene glycol, polyvinyl alcohol, and polyvinylpyrrolidone; the biological molecule type regulator preferably comprises one or more of oxalic acid, glutamic acid, citric acid, malic acid, tartaric acid, succinic acid, glycine, aspartic acid, polysaccharide, casein, chitin, chitosan, heparin, carbonic anhydrase, lipase, and protease; and the mass concentration of the crystal form regulator is preferably 0.04~0.14%, and particularly preferably 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, or 0.14%. In the present application, the mass concentration of the crystal form regulator is 0.04~0.14%, which is conducive to the growth of the mineralized layer (calcium carbonate or calcium phosphate) crystals, forms a more compact mineralized layer structure, and regulates the mechanical properties of the mineralized layer by refining the crystal grains and substituting lattice defects.

[0083] In the present application, the preparation method of the third precursor solution preferably comprises the following steps: mixing and stirring calcium salt and water (denoted as the fifth mixing and stirring), to obtain a calcium salt solution; adding ion-dragging agent and crystal form regulator into the calcium salt solution in sequence, to obtain the third precursor solution. In the present application, the time of the fifth mixing and stirring is preferably equal to or greater than 10 min, and further preferably 25-45 min. In the present application, after the addition of the ion-dragging agent, mixing and stirring is preferably performed (denoted as the sixth mixing and stirring), and the time of the sixth mixing and stirring is preferably equal to or greater than 6 min, and further preferably 25-45 min. In the present application, after the addition of the crystal form regulator, mixing and stirring is preferably performed (denoted as the seventh mixing and stirring), and the time of the seventh mixing and stirring is preferably equal to or greater than 5 min, and further preferably 10-35 min.

[0084] In the present application, the fourth precursor solution comprises carbonate or phosphate. In the present application, the solvent of the fourth precursor solution preferably comprises water.

[0085] In the present application, in the fourth precursor solution, carbonate is preferably provided by one or more of lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, cesium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, rubidium bicarbonate, cesium bicarbonate, ammonium bicarbonate, methylamine carbonate, calcium bicarbonate, magnesium bicarbonate, barium bicarbonate, zinc bicarbonate, iron bicarbonate, aluminum bicarbonate, ethylenediamine carbonate, dimethyl carbonate and ethylene carbonate; and phosphate is preferably provided by one or more of lithium phosphate, sodium phosphate, potassium phosphate, beryllium phosphate, calcium phosphate, trisodium phosphate, tripotassium phosphate, triammonium phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, calcium dihydrogen phosphate, ammonium dihydrogen phosphate, dipotassium hydrogen phosphate, disodium hydrogen phosphate, diammonium hydrogen phosphate and triethyl phosphate.

[0086] In the present application, in the fourth precursor solution, the mass concentration of carbonate and phosphate is independently preferably 0.35-2.5 wt%, and particularly preferably 0.35 wt%, 0.5 wt%, 0.75 wt%, 1 wt%, 1.25 wt%, 1.5 wt%, 1.75 wt%, 2 wt%, 2.25 wt% or 2.5 wt%.

[0087] In the present application, the preparation method of the fourth precursor solution preferably comprises the following step: mixing and stirring carbonate or phosphate and water (eighth mixing and stirring), to obtain the fourth precursor solution. In the present application, the time of the eighth mixing and stirring is preferably equal to or greater than 5 min, and further preferably 15-45 min.

[0088] In the present application, the fourth precursor solution preferably completes dropping in 12-36 h, and further preferably 24-28 h.

[0089] After the fourth precursor solution is added dropwise, the application preferably further comprises taking out the substrate sample, and then sequentially washing and air-drying the substrate sample. In the application, the washing mode is preferably rinsing, and the washing reagent is preferably deionized water. The application does not specifically limit the air-drying mode.

[0090] In the application, when the inducing layer and the organic-functional material layer are preferably provided with a base layer, the application further comprises: preparing a base layer on the inducing layer of the substrate / inducing layer, to obtain a substrate / inducing layer / base layer. In the application, the preparation of the base layer preferably comprises the following steps: placing the substrate / inducing layer into a first precursor solution, and then adding a second precursor solution dropwise.

[0091] In the application, the first precursor solution preferably comprises a calcium salt and an ion-dragging agent. In the application, the kind of the ion-dragging agent is preferably consistent with the above technical solution, which will not be repeated here. In the application, the mass concentration of the ion-dragging agent is preferably 1.25×10 -3 ~ 2.25×10 -3 %, and more preferably 1.25×10 -3 %, 1.5×10 -3 wt%, 1.75×10 -3 wt%, 2×10 -3 wt% or 2.25×10 -3 wt%. In the application, the first precursor solution preferably comprises a calcium salt and an ion-dragging agent. In the application, the solvent of the first precursor solution preferably comprises water. In the application, in the first precursor solution, the kind of the calcium salt is preferably consistent with the above technical solution, which will not be repeated here, and the mass concentration of the calcium salt is preferably 0.25~1.5%, and more preferably 0.25%, 0.5%, 0.75%, 1%, 1.15%, 1.25% or 1.5%. In the application, the mass concentration of the ion-dragging agent in the first precursor solution is controlled to be 1.25×10 -3 ~ 2.25×10 -3% and is conducive to bidirectional reaction. The -COOH on the long chain of the ion-dragging agent in the first precursor solution interacts with the -OH and / or -NH2 on the surface of the inducer, resulting in adsorption of the ion-dragging agent on the surface of the inducer to form a polyelectrolyte complex (PEC). Meanwhile, the ion-dragging agent can also attract calcium salt in the first precursor solution, resulting in a local increase in the concentration of calcium ions on the surface of the inducer layer, and inducing nucleation of calcium carbonate or calcium phosphate to form the base layer. In the present application, the preparation method of the first precursor solution preferably comprises the following steps: stirring and mixing calcium salt and water (denoted as second stirring and mixing) to obtain a calcium salt solution; stirring and mixing the calcium salt solution and the ion-dragging agent (denoted as third stirring and mixing) to obtain the first precursor solution. In the present application, the second stirring time is preferably greater than or equal to 5 min, and further preferably 15-40 min. In the present application, the third stirring and mixing time is preferably greater than or equal to 3 min, and further preferably 10-30 min.

[0092] In the present application, the second precursor solution comprises carbonate or phosphate. In the present application, the solvent of the second precursor solution preferably comprises water. In the present application, the source of carbonate in the second precursor solution is preferably consistent with the above technical solutions, which will not be repeated here; the source of phosphate in the second precursor solution is preferably consistent with the above technical solutions, which will not be repeated here. In the present application, the mass concentration of carbonate and phosphate in the second precursor solution is independently preferably 0.25-1.5%, and specifically preferably 0.25%, 0.5%, 0.75%, 1%, 1.15%, 1.25% or 1.5%. In the present application, the preparation method of the second precursor solution preferably comprises the following step: stirring and mixing carbonate or phosphate and water (fourth stirring and mixing) to obtain the second precursor solution. In the present application, the fourth stirring and mixing time is preferably greater than or equal to 5 min, and further preferably 15-35 min.

[0093] In the present application, the second precursor solution preferably completes dropping within 8-24 h.

[0094] After the dropping of the second precursor solution is completed, the present application preferably further comprises taking out the substrate sample, and then sequentially performing water washing and air drying on the substrate sample. In the present application, the water washing mode is preferably flushing, and the water washing reagent is preferably deionized water. The present application does not specifically limit the air drying mode.

[0095] In the present application, the base layer serves as an adhesion layer between the substrate and the subsequent organic-functional material layer, improving the adhesion; and can provide more nucleation sites to promote the growth of the mineralization layer.

[0096] After the preparation of the mineralized layer, the application further comprises repeating the process of sequentially preparing the induction layer, the organic-functional material layer and the mineralized layer on the mineralized layer.

[0097] The application realizes the synergistic induced mineralization of the base layer and the organic-functional material layer through the multi-layer structure design of the induction layer / base layer / organic-functional material layer / mineralized layer, breaks through the limitations of traditional single coating or simple superposition structure, and constructs a composite protection system with dynamic interaction. In the application, the organic-functional material layer not only serves as a corrosion barrier component, but also deeply participates in the formation process of the mineralized layer. The organic-functional material layer has a large surface area and can provide a large number of nucleation sites for subsequent mineralization. The functional materials in the organic-functional material layer are embedded in the mineralized structure through chemical bonding and interfacial action, realizing the "in-situ fixation" of the corrosion protection component, solving the problems of easy migration and insufficient long-acting of traditional corrosion protection additives, and increasing the toughness of the overall coating. The organic-functional material layer and the base layer can provide a large number of nucleation sites for the growth of the mineralized layer, which is more conducive to the in-situ growth of the mineralized layer. Moreover, the application is directed to the defect that the surface corrosion resistance and mechanical properties are not taken into account. The dense mineralized layer and the organic-functional material layer block the penetration path of chloride ions while having excellent mechanical properties. Therefore, the introduction of functional materials between inorganic layers can promote the formation of inorganic mineralized layers while constructing a double protection mechanism: realizing mechanical properties and corrosion protection at the same time. This synergistic mechanism can greatly improve the corrosion protection life of the substrate, meeting the needs of long-life infrastructure construction. The organic-functional material layer and the base layer in the application jointly provide induction effect and template effect, which can precisely control the nucleation sites, growth direction and microstructure of the mineralized layer, form a composite protective layer that is firmly combined with the substrate, has high density, and has mechanical support and corrosion protection functions, and improve the overall durability of the coating system. In addition, complex service environments require coatings to have performance gradient distribution capability. The application constructs a multi-layer gradient functional structure through programmed layering control technology. This modular design can quickly customize coating systems suitable for different scenarios by adjusting the composition and thickness of each layer, promoting the upgrade of concrete coatings from "single protection" to "functional composite system".

[0098] The application further provides the application of the protective coating in metal material protection, ceramic material protection and cement material protection.

[0099] The application mode of the protective coating is not specifically limited, and those skilled in the art can set it according to actual needs.

[0100] The protective coating, the preparation method and the application thereof provided by the application will be described in detail below in combination with examples, but they should not be understood as limiting the scope of protection of the application.

[0101] Example 1

[0102] Preparation of concrete matrix: Weighed P.O 42.5 cement and sand were mixed in a mixing pot, the sand was standard siliceous sand with particle size less than 2 mm, and the water-cement ratio (W / C) was 0.4. The mixer was started and stirred at a slow speed for 120 s; an appropriate amount of water was added; after stirring at a slow speed for 120 s, the mixer was started and stirred at a fast speed for 30 s; the formed cement paste was taken out; the steel mold with the cement mortar was placed on a vibrating table to vibrate to ensure the uniformity of the paste; after the surface floating paste of the pouring surface was scraped, a layer of plastic film was covered on the surface to prevent water evaporation from the paste. The test block was demolded after 24 h under standard curing, and then placed in a curing room (20 ± 2 ℃, humidity ≥ 95%) for curing for 28 d. The cured test block was cut into a test block with a size of 10 mm × 10 mm × 5 mm, and polished and washed to be used as the concrete matrix.

[0103] Preparation of inducer solution: chitosan and acetic acid solution (1wt% of acetic acid) were stirred and mixed for 12 h to obtain a chitosan solution with a content of 0.80wt%.

[0104] Preparation of first precursor solution: calcium chloride and water were stirred and mixed for 15 min to obtain a calcium chloride solution with a content of 0.5wt%; polyacrylic acid was added to the calcium chloride solution, and stirred and mixed for 10 min to make the content of polyacrylic acid 1.25 × 10 - 3 wt%.

[0105] Preparation of second precursor solution: sodium carbonate and water were stirred and mixed for 15 min to obtain a sodium carbonate solution with a content of 0.5wt%.

[0106] Preparation method of organic-functional material composite system: a zirconium phosphate solution with a content of 0.80wt% was taken, and zirconium phosphate was added thereto, and ultrasonic treatment was performed for 15 min to make the content of zirconium phosphate 0.40wt%.

[0107] Preparation of third precursor solution: calcium chloride and water were stirred and mixed for 25 min to obtain a calcium chloride solution with a content of 0.75wt%; polyacrylic acid was added to the calcium chloride solution, and stirred and mixed for 10 min to make the content of polyacrylic acid 1.5 × 10 - 3 wt%; then magnesium chloride was continuously added and stirred and mixed for 15 min to make the content of magnesium chloride 0.08wt%.

[0108] Preparation of fourth precursor solution: sodium carbonate and water were stirred and mixed for 15 min to obtain a sodium carbonate solution with a content of 0.75wt%.

[0109] The concrete substrate was ultrasonically treated in anhydrous ethanol for 15 min, then washed with deionized water, and dried to obtain a pretreated concrete substrate.

[0110] The pretreated concrete substrate was dripped with an inducing agent solution, spin-coated at 1000 rpm for 10 s, and then spin-coated at 3500 rpm for 35 s to obtain a substrate / inducing layer.

[0111] The substrate / inducing layer was then placed in a first precursor solution, and then dripped with a second precursor solution, and the dripping of the second precursor solution was completed in 12 h; the obtained substrate sample was taken out, washed with deionized water, and dried to obtain a substrate / inducing layer / base layer.

[0112] The base layer of the substrate / inducing layer / base layer was dripped with an organic-functional material composite system, spin-coated at 1200 rpm for 20 s, and then spin-coated at 4000 rpm for 25 s to obtain a substrate / inducing layer / base layer / organic-functional material layer.

[0113] The substrate / inducing layer / base layer / organic-functional material layer was placed in a third precursor solution, and then dripped with a fourth precursor solution, and the dripping of the fourth precursor solution was completed in 24 h; the substrate sample was washed with deionized water and dried to form a sample with a protective coating attached.

[0114] Figure 1 and Figure 2 The SEM images of the organic-functional material layer in the substrate / inducing layer / base layer / organic-functional material layer at different magnifications are shown in FIGS. 6A and 6B. Figure 1 and Figure 2 It can be seen that the organic-functional material layer has a large surface area, which can provide abundant calcium carbonate or calcium phosphate nucleation sites, and the -COOH on the long chain of polyacrylic acid interacts with the -OH and -NH2 on the surface of chitosan; at the same time, polyacrylic acid can attract calcium ions in the solution, resulting in an increase in the local calcium ion concentration on the surface of the chitosan organic layer, inducing calcium carbonate nucleation, and further forming a complete mineralization layer in combination with the induction of the mineralization precursor layer.

[0115] Figure 3 The SEM images of the mineralization layer in the protective coating are shown in FIGS. 7A and 7B. Figure 3 It can be seen that the surface of the mineralization layer has a unique structure of a tessellation polygon pattern, which can also be found in the structure of a shell, with nanoscale CaCO3 particles closely combined. This high-density packing structure consumes a large amount of energy to hinder the propagation of cracks in the coating during the expansion of the cracks caused by external impacts and other factors, and the addition of functional units in the organic layer enhances the toughness of the overall coating. In addition, the dense calcium carbonate coating leads to a decrease in capillary water absorption, combined with the blocking effect of the functional units, thereby forming a dual anti-corrosion mechanism.

[0116] Figure 4 The microhardness of the concrete substrate (corresponding to the reference group in the figure) and the sample attached with the protective coating of Example 1 (corresponding to the mineralized group in the figure) is shown in the figure from Figure 4 It can be seen that the hardness of the mineralized group (165.3 HV) is higher than that of the reference group (54.7 HV), and the difference is 110.6 HV, which shows that the mineralization treatment has a significant effect on improving the hardness. This is because the mineralization process reasonably controls the variables, and the mineralization process introduces the base layer and the organic-functional material. The base layer and the organic-functional material layer can provide a large number of nucleation sites for the growth of the mineralized layer, which is more conducive to the in-situ growth of the mineralized layer, and then improves the microstructure, makes the nanostructure combination of the coating more compact, and strengthens the hardness of the coating.

[0117] The sample attached with the protective coating was subjected to 7-day electrochemical impedance spectroscopy test, and the impedance was measured to be 6.53 x 10 5 Ω·cm 2 .

[0118] Example 2

[0119] The preparation method of the concrete substrate is the same as that of Example 1.

[0120] Preparation of the inducer solution: chitosan and acetic acid solution (1wt% of acetic acid) were stirred and mixed for 14h to obtain a chitosan solution with a content of 1.0wt%.

[0121] Preparation of the first precursor solution: calcium chloride and water were stirred and mixed for 20min to obtain a calcium chloride solution with a content of 0.75wt%; polyacrylic acid was added to the calcium chloride solution and stirred and mixed for 15min to make the content of polyacrylic acid 1.75 x 10 - 3 wt%.

[0122] Preparation of the second precursor solution: sodium carbonate and water were stirred and mixed for 15min to obtain a sodium carbonate solution with a content of 0.75wt%.

[0123] Preparation method of the organic-functional material composite system: take the chitosan solution with a content of 1.0wt%, add zirconium phosphate to it, and ultrasonic treat for 25min to make the content of zirconium phosphate 0.3wt%.

[0124] Preparation of the third precursor solution: calcium chloride and water were stirred and mixed for 25min to obtain a calcium chloride solution with a content of 1.25wt%; polyacrylic acid was added to the calcium chloride solution and stirred and mixed for 10min to make the content of polyacrylic acid 1.5 x 10 - 3 wt%; then continue to add magnesium chloride and stir and mix for 15min to make the content of magnesium chloride 0.07wt%.

[0125] Preparation of the fourth precursor solution: sodium carbonate and water were stirred and mixed for 15 min to obtain a sodium carbonate solution with a content of 1.25 wt%.

[0126] The concrete substrate was ultrasonically treated in anhydrous ethanol for 15 min, then rinsed with deionized water and dried to obtain a pretreated concrete substrate.

[0127] The inducer solution was added dropwise to the pretreated concrete substrate, and spin-coated at 1000 rpm for 15 s, then at 4000 rpm for 45 s, and spin-coated was stopped, to obtain a substrate / induction layer.

[0128] The substrate / induction layer was then placed in the first precursor solution, and the second precursor solution was added dropwise, and the second precursor solution was added dropwise for 12 h; the obtained substrate sample was taken out, rinsed with deionized water and air-dried to obtain a substrate / induction layer / base layer.

[0129] The organic-functional material composite system was added dropwise to the base layer of the substrate / induction layer / base layer, and spin-coated at 1100 rpm for 25 s, then at 3500 rpm for 35 s, to obtain a substrate / induction layer / base layer / organic-functional material layer.

[0130] The substrate / induction layer / base layer / organic-functional material layer was placed in the third precursor solution, and the fourth precursor solution was added dropwise, and the fourth precursor solution was added dropwise for 28 h; the substrate sample was rinsed with deionized water and air-dried to form a sample with a protective coating attached.

[0131] Figure 5 The microhardness maps of the concrete substrate (corresponding to the reference group in the figure) and the sample with a protective coating attached of Example 2 (corresponding to the mineralized group in the figure) were obtained from Figure 5 It can be seen that the hardness of the mineralized group (145.3 HV) is higher than that of the reference group (55.6 HV), and the difference is 89.7 HV, which shows that the mineralization process has a significant effect on improving the hardness, because the mineralization process reasonably controls the variables, and the mineralization process introduces the base layer and the organic-functional material, and the base layer and the organic-functional material layer can provide a large number of nucleation sites for the growth of the mineralized layer, which is more conducive to the in-situ growth of the mineralized layer, and thus improves the microstructure, makes the nanostructure combination of the coating more compact, and strengthens the hardness of the coating.

[0132] The sample with a protective coating attached was taken for 7-day electrochemical impedance spectroscopy test, and the impedance was measured to be 3.73 x 10 5 Ω·cm 2 .

[0133] Example 3

[0134] The preparation method of the concrete substrate was the same as that of Example 1.

[0135] Preparation of the inducer solution: chitosan and acetic acid solution (1wt% of acetic acid) were stirred and mixed for 16h to obtain a chitosan solution with a content of 1.2wt%.

[0136] Preparation of the first precursor solution: calcium chloride and water were stirred and mixed for 20min to obtain a calcium chloride solution with a content of 0.95wt%; polyacrylic acid was added to the calcium chloride solution and stirred and mixed for 15min to make the content of polyacrylic acid 1.75x10 - 3 wt%.

[0137] Preparation of the second precursor solution: sodium carbonate and water were stirred and mixed for 15min to obtain a sodium carbonate solution with a content of 0.95wt%.

[0138] Preparation method of the organic-functional material composite system: zirconium phosphate was added to the chitosan solution with a content of 1.2wt% and ultrasonic treated for 25min to make the content of zirconium phosphate 0.20wt%.

[0139] Preparation of the third precursor solution: calcium chloride and water were stirred and mixed for 25min to obtain a calcium chloride solution with a content of 1.75wt%; polyacrylic acid was added to the calcium chloride solution and stirred and mixed for 10min to make the content of polyacrylic acid 1.75x10 - 3 wt%; then magnesium chloride was continuously added and stirred and mixed for 15min to make the content of magnesium chloride 0.06wt%.

[0140] Preparation of the fourth precursor solution: sodium carbonate and water were stirred and mixed for 15min to obtain a sodium carbonate solution with a content of 1.75wt%.

[0141] The concrete substrate was ultrasonic treated in anhydrous ethanol for 15min, then rinsed with deionized water and dried to obtain a pretreated concrete substrate.

[0142] The inducer solution was added dropwise to the pretreated concrete substrate, first spin-coated at 1000rpm for 15s, then spin-coated at 3500rpm for 45s and stopped to obtain a substrate / induction layer.

[0143] Then the substrate / induction layer was placed in the first precursor solution, then the second precursor solution was added dropwise, and the second precursor solution was added dropwise for 14h; the obtained substrate sample was taken out, rinsed with deionized water and dried to obtain a substrate / induction layer / basic layer.

[0144] The organic-functional material composite system was added dropwise to the basic layer of the substrate / induction layer / basic layer, spin-coated at 1200rpm for 25s, then spin-coated at 4000rpm for 30s to obtain a substrate / induction layer / basic layer / organic-functional material layer.

[0145] The substrate / induction layer / base layer / organic-functional material layer is placed into the third precursor solution, and then the fourth precursor solution is added dropwise, and the fourth precursor solution is added dropwise for 24 h; the substrate sample is washed with deionized water and dried to form a sample with a protective coating attached.

[0146] Figure 6 The microhardness of the concrete substrate (corresponding to the reference group in the figure) and the sample with the protective coating attached according to Example 3 (corresponding to the mineralized group in the figure) is obtained from Figure 6 It can be seen that the hardness of the mineralized group (132.4 HV) is higher than that of the reference group (53.7 HV), and the difference is 78.7 HV, which shows that the mineralization process has a significant effect on improving the hardness, because the mineralization process reasonably controls the variables, and the base layer and the organic-functional material are introduced in the mineralization process, and the base layer and the organic-functional material layer can provide a large number of nucleation sites for the growth of the mineralized layer, which is more conducive to the in-situ growth of the mineralized layer, and thus improves the microstructure, makes the nanostructure combination of the coating more compact, and strengthens the hardness of the coating.

[0147] The sample with the protective coating attached is taken for 7-day electrochemical impedance spectroscopy testing, and the impedance is measured to be 2.14 x 10 5 Ω·cm 2 .

[0148] Example 4

[0149] The preparation method of the concrete substrate is the same as that of Example 1.

[0150] Preparation of the inducer solution: chitosan and acetic acid solution (1wt% of acetic acid) are stirred and mixed for 14 h to obtain a chitosan solution with a content of 1.5wt%.

[0151] Preparation of the first precursor solution: calcium chloride and water are stirred and mixed for 25 min to obtain a calcium chloride solution with a content of 1.15wt%; polyacrylic acid is added to the calcium chloride solution and stirred and mixed for 15 min to make the content of polyacrylic acid 1.5 x 10 - 3 wt%.

[0152] Preparation of the second precursor solution: sodium carbonate and water are stirred and mixed for 15 min to obtain a sodium carbonate solution with a content of 1.15wt%.

[0153] Preparation method of the organic-functional material composite system: take the chitosan solution with a content of 1.5wt%, and add zirconium phosphate to it, and ultrasonic treatment for 30 min to make the content of zirconium phosphate 0.55wt%.

[0154] Preparation of the third precursor solution: calcium chloride and water were stirred and mixed for 15 min to obtain a calcium chloride solution with a content of 2.25 wt%; polyacrylic acid was added to the calcium chloride solution and stirred and mixed for 15 min to obtain a polyacrylic acid content of 2.0 x 10 - 3 wt%; magnesium chloride was then continuously added and stirred and mixed for 25 min to obtain a magnesium chloride content of 0.09 wt%.

[0155] Preparation of the fourth precursor solution: sodium carbonate and water were stirred and mixed for 15 min to obtain a sodium carbonate solution with a content of 2.25 wt%.

[0156] The concrete substrate was ultrasonically treated in anhydrous ethanol for 15 min, then washed with deionized water and dried to obtain a pretreated concrete substrate.

[0157] The inducer solution was added dropwise to the pretreated concrete substrate, and spin-coated at 1100 rpm for 15 s, then spin-coated at 5000 rpm for 45 s, and the spin-coating was stopped to obtain a substrate / induction layer.

[0158] The substrate / induction layer was then placed in the first precursor solution, and the second precursor solution was added dropwise, and the second precursor solution was added dropwise for 14 h; the obtained substrate sample was taken out, washed with deionized water and air-dried to obtain a substrate / induction layer / base layer.

[0159] The organic-functional material composite system was added dropwise to the base layer of the substrate / induction layer / base layer, and spin-coated at 1300 rpm for 25 s, then spin-coated at 3500 rpm for 30 s to obtain a substrate / induction layer / base layer / organic-functional material layer.

[0160] The substrate / induction layer / base layer / organic-functional material layer was placed in the third precursor solution, and the fourth precursor solution was added dropwise, and the fourth precursor solution was added dropwise for 36 h; the substrate sample was washed with deionized water and air-dried to form a sample with a protective coating attached.

[0161] Figure 7 The microhardness of the concrete substrate (corresponding to the reference group in the figure) and the sample with a protective coating attached to the concrete substrate of Example 4 (corresponding to the mineralized group in the figure) was measured, and the results are shown in Table 1. Figure 7 It can be seen that the hardness of the mineralized group (151.9 HV) is higher than that of the reference group (54.1 HV), and the difference is as high as 97.8 HV, which indicates that the mineralization process has a significant effect on improving the hardness. This is because the mineralization process reasonably controls the variables, and the introduction of the base layer and the organic-functional material in the mineralization process provides a large number of nucleation sites for the growth of the mineralized layer, which is more conducive to the in-situ growth of the mineralized layer, and thus improves the microstructure, making the nanostructure combination of the coating more compact, and strengthening the hardness of the coating.

[0162] The sample with the protective coating attached thereon was subjected to electrochemical impedance spectroscopy test for 7 days, and the impedance was measured to be 3.65 x 10 5 Ω·cm 2 .

[0163] Example 5

[0164] The difference from Example 1 is that the base layer is not provided.

[0165] Preparation of the inducer solution: chitosan and acetic acid solution (1wt% of acetic acid) were stirred and mixed for 12h to obtain a chitosan solution with a content of 0.80wt%.

[0166] Preparation method of the organic-functional material composite system: a chitosan solution with a content of 0.80wt% was taken, and zirconium phosphate was added thereto and ultrasonically treated for 15min to make the content of zirconium phosphate 0.40wt%.

[0167] Preparation of the third precursor solution: calcium chloride and water were stirred and mixed for 25min to obtain a calcium chloride solution with a content of 0.75wt%; polyacrylic acid was added to the calcium chloride solution and stirred and mixed for 10min to make the content of polyacrylic acid 1.5 x 10 - 3 wt%; then magnesium chloride was continuously added and stirred and mixed for 15min to make the content of magnesium chloride 0.08wt%.

[0168] Preparation of the fourth precursor solution: sodium carbonate and water were stirred and mixed for 15min to obtain a sodium carbonate solution with a content of 0.75wt%.

[0169] The concrete substrate was ultrasonically treated in anhydrous ethanol for 15min, then washed with deionized water and dried to obtain a pretreated concrete substrate.

[0170] The inducer solution was dropped on the pretreated concrete substrate, and spin-coated at 1200rpm for 20s and then at 4000rpm for 25s to obtain a substrate / induction layer.

[0171] Then the organic-functional material composite system was dropped on the induction layer of the substrate / induction layer, and spin-coated at 1000rpm for 20s and then at 3500rpm for 25s to obtain a substrate / induction layer / organic-functional material layer.

[0172] The substrate / induction layer / organic-functional material layer was placed in the third precursor solution, and then the fourth precursor solution was dropped, and the dropping of the fourth precursor solution was completed in 24h; the substrate sample was washed with deionized water and dried to form a sample with a protective coating attached thereon.

[0173] The sample with the protective coating attached was subjected to microhardness testing, and the hardness was 103.78 HV.

[0174] The sample was subjected to 7-day electrochemical impedance spectroscopy testing, and the impedance was 9.32 x 10 4 Ω·cm2.

[0175] Comparative Example 1

[0176] The concrete substrate was prepared in the same manner as in Example 1.

[0177] Preparation of the inducer solution: chitosan and acetic acid solution (1 wt% of acetic acid) were stirred and mixed for 12 h to obtain a chitosan solution with a content of 1.0 wt%.

[0178] Preparation of the first precursor solution: calcium chloride and water were stirred and mixed for 25 min to obtain a calcium chloride solution with a content of 0.75 wt%; polyacrylic acid was added to the calcium chloride solution, and stirred and mixed for 15 min to obtain a content of 1.5 x 10 - 3 wt%.

[0179] Preparation of the second precursor solution: sodium carbonate and water were stirred and mixed for 15 min to obtain a sodium carbonate solution with a content of 0.75 wt%.

[0180] Preparation of the organic-functional material composite system: zirconium phosphate was added to the chitosan solution with a content of 1.0 wt%, and ultrasonic treatment was performed for 25 min to obtain a content of 0.35 wt%.

[0181] Preparation of the third precursor solution: calcium chloride and water were stirred and mixed for 25 min to obtain a calcium chloride solution with a content of 2.0 wt%; polyacrylic acid was added to the calcium chloride solution, and stirred and mixed for 15 min to obtain a content of 2.0 x 10 - 3 wt%; then magnesium chloride was continuously added and stirred and mixed for 25 min to obtain a content of 0.20 wt%.

[0182] Preparation of the fourth precursor solution: sodium carbonate and water were stirred and mixed for 15 min to obtain a sodium carbonate solution with a content of 2.0 wt%.

[0183] The concrete substrate was ultrasonically treated in anhydrous ethanol for 15 min, then washed with deionized water, and dried to obtain a pretreated concrete substrate.

[0184] The inducer solution was added dropwise to the pretreated concrete substrate, and spin coating was performed at 800 rpm for 15 s, then spin coating was performed at 2500 rpm for 45 s, and spin coating was stopped to obtain a substrate / induction layer.

[0185] Comparative Example 1Then the substrate / induction layer is put into the first precursor solution, and then the second precursor solution is added dropwise, and the second precursor solution is added dropwise for 12 h; the obtained substrate sample is taken out, washed with deionized water, and dried to obtain the substrate / induction layer / substrate layer.

[0186] The organic-functional material composite system is added dropwise on the substrate / induction layer / substrate layer, and then spin-coated at 800 rpm for 20 s, and then spin-coated at 2500 rpm for 35 s to obtain the substrate / induction layer / substrate layer / organic-functional material layer.

[0187] The substrate / induction layer / substrate layer / organic-functional material layer is put into the third precursor solution, and then the fourth precursor solution is added dropwise, and the fourth precursor solution is added dropwise for 72 h; the substrate sample is washed with deionized water, and dried to form a sample with a protective coating attached.

[0188] Figure 8 The microhardness diagram of the concrete substrate (corresponding to the reference group in the figure) and the sample with a protective coating attached (corresponding to the mineralization group in the figure) of Comparative Example 1 is shown in FIG. 6. Figure 8 It can be seen that: the hardness of the mineralization group (96.43 HV) is higher than that of the reference group (55.31 HV), but the difference is less than that of other examples, which is 41.12 HV, indicating that if the magnesium ions are excessive, they will replace part of the key ion sites in the crystal, and too much magnesium will disrupt the arrangement of the crystal, making the crystal structure loose and reducing the density of the mineralization layer. Mineralization depends on ion balance and deposition rate. And too much magnesium will compete with calcium for binding sites, interfere with mineralization function, and make the mineral deposition "rhythm" disorder, so that high-quality mineralization layer cannot be formed, and the hardness decreases.

[0189] The sample with a protective coating attached is taken for 7-day electrochemical impedance spectroscopy test, and the impedance is measured to be 7.91 x 10 4 Ω·cm 2 .

[0190] Figure 9 The SEM diagram of the mineralization layer of the sample with a protective coating attached at different magnifications is shown in FIG. 7. Figure 9 It can be seen that: due to the excessive content of magnesium ions on the surface of the mineralization layer, the excessive concentration leads to the enrichment of Mg at the grain boundaries, forming a weakly bound area, resulting in a decrease in the mechanical properties of the coating, and the surface of the mineralization layer is extended due to the extension of the mineralization time, resulting in the formation of irregular calcium carbonate particles on the surface.

[0191] Comparative Example 2

[0192] The preparation method of the concrete substrate is the same as that of Example 1.

[0193] Preparation of the inducer solution: chitosan and acetic acid solution (1wt% of acetic acid) are stirred and mixed for 14 h to obtain a chitosan solution with a content of 0.8wt%.

[0194] Preparation of the first precursor solution: calcium chloride and water were stirred and mixed for 15 min to obtain a calcium chloride solution with a content of 0.5 wt%; polyacrylic acid was added to the calcium chloride solution, and stirred and mixed for 10 min to make the content of polyacrylic acid 1.25 x 10 - 3 wt%.

[0195] Preparation of the second precursor solution: sodium carbonate and water were stirred and mixed for 15 min to obtain a sodium carbonate solution with a content of 0.5 wt%.

[0196] Preparation method of the organic-functional material composite system: a chitosan solution with a content of 0.8 wt% was taken, and zirconium phosphate was added thereto, and ultrasonic treatment was performed for 15 min to make the content of zirconium phosphate 0.45 wt%.

[0197] Preparation of the third precursor solution: calcium chloride and water were stirred and mixed for 25 min to obtain a calcium chloride solution with a content of 1.75 wt%; polyacrylic acid was added to the calcium chloride solution, and stirred and mixed for 10 min to make the content of polyacrylic acid 0.25 x 10 - 3 wt%; then magnesium chloride was continuously added and stirred and mixed for 15 min to make the content of magnesium chloride 0.04 wt%.

[0198] Preparation of the fourth precursor solution: sodium carbonate and water were stirred and mixed for 15 min to obtain a sodium carbonate solution with a content of 1.75 wt%.

[0199] The concrete substrate was ultrasonically treated in anhydrous ethanol for 15 min, then washed with deionized water, and dried to obtain a pretreated concrete substrate.

[0200] The inducer solution was added dropwise to the pretreated concrete substrate, and spin-coated at 1000 rpm for 10 s, then spin-coated at 4000 rpm for 35 s, and the spin-coating was stopped to obtain a substrate / induction layer.

[0201] Then the substrate / induction layer was placed in the first precursor solution, and then the second precursor solution was added dropwise, and the second precursor solution was added dropwise for 12 h; the obtained substrate sample was taken out, washed with deionized water, and air-dried to obtain a substrate / induction layer / basic layer.

[0202] The organic-functional material composite system was added dropwise to the basic layer of the substrate / induction layer / basic layer, and spin-coated at 1200 rpm for 20 s, and then spin-coated at 3500 rpm for 25 s to obtain a substrate / induction layer / basic layer / organic-functional material layer.

[0203] The substrate / induction layer / base layer / organic-functional material layer is placed into the third precursor solution, and then the fourth precursor solution is added dropwise. The fourth precursor solution is added dropwise for 24 h. The substrate sample is rinsed with deionized water and dried to form a sample with a protective coating attached thereto.

[0204] Figure 10 The SEM images of the mineralized layer of the sample with a protective coating at different magnifications are shown in FIG. 2. Figure 10 It can be seen that the surface of the mineralized layer is covered with a large number of calcium ions that have not been chelated due to the low concentration of polyacrylic acid, resulting in the formation of a disc-shaped structure and a large number of calcium carbonate particles attached to the surface.

[0205] Comparative Example 3

[0206] The difference from Example 1 is that the organic-functional material layer is not provided.

[0207] Preparation of the inducer solution: chitosan and acetic acid solution (1 wt% of acetic acid) are stirred and mixed for 12 h to obtain a chitosan solution with a content of 0.80 wt%.

[0208] Preparation of the first precursor solution: calcium chloride and water are stirred and mixed for 15 min to obtain a calcium chloride solution with a content of 0.75 wt%. Polyacrylic acid is added to the calcium chloride solution and stirred and mixed for 10 min to obtain a polyacrylic acid content of 1.25 x 10 - 3 wt%.

[0209] Preparation of the second precursor solution: sodium carbonate and water are stirred and mixed for 15 min to obtain a sodium carbonate solution with a content of 0.75 wt%.

[0210] Preparation of the third precursor solution: calcium chloride and water are stirred and mixed for 25 min to obtain a calcium chloride solution with a content of 0.75 wt%. Polyacrylic acid is added to the calcium chloride solution and stirred and mixed for 10 min to obtain a polyacrylic acid content of 1.5 x 10 - 3 wt%. Then, magnesium chloride is continuously added and stirred and mixed for 15 min to obtain a magnesium chloride content of 0.08 wt%.

[0211] Preparation of the fourth precursor solution: sodium carbonate and water are stirred and mixed for 15 min to obtain a sodium carbonate solution with a content of 0.75 wt%.

[0212] The concrete substrate is ultrasonically treated in anhydrous ethanol for 15 min, then rinsed with deionized water and dried to obtain a pretreated concrete substrate.

[0213] The inducer solution was dropped on the pretreated concrete substrate, and then spin-coated at 1000 rpm for 15 s and at 3500 rpm for 35 s to obtain the substrate / induction layer.

[0214] Then the substrate / induction layer was placed in the first precursor solution, and then the second precursor solution was dropped, and the dropping of the second precursor solution was completed in 18 h; the obtained substrate sample was taken out, washed with deionized water, and dried to obtain the substrate / induction layer / substrate layer.

[0215] The substrate / induction layer / substrate layer was placed in the third precursor solution, and then the fourth precursor solution was dropped, and the dropping of the fourth precursor solution was completed in 18 h; the obtained substrate sample was taken out, washed with deionized water, and dried to obtain the substrate / induction layer / substrate layer / mineralized layer.

[0216] The obtained substrate / induction layer / substrate layer / mineralized layer was subjected to microhardness test, and the hardness was 87.56 HV.

[0217] The obtained substrate / induction layer / substrate layer / mineralized layer was subjected to 7-day electrochemical impedance spectroscopy test, and the impedance was 3.75×10 4 Ω·cm 2 .

[0218] Comparative Example 4

[0219] The preparation method of the concrete substrate was the same as that in Example 1.

[0220] Preparation of the inducer solution: chitosan and acetic acid solution (1wt% of acetic acid) were stirred and mixed for 14 h to obtain a chitosan solution with a content of 1.0wt%.

[0221] Preparation of the third precursor solution: calcium chloride and water were stirred and mixed for 25 min to obtain a calcium chloride solution with a content of 1.25wt%; polyacrylic acid was added to the calcium chloride solution and stirred and mixed for 10 min to obtain a polyacrylic acid content of 1.5×10 - 3 wt%; then magnesium chloride was continuously added and stirred and mixed for 15 min to obtain a magnesium chloride content of 0.07wt%.

[0222] Preparation of the fourth precursor solution: sodium carbonate and water were stirred and mixed for 15 min to obtain a sodium carbonate solution with a content of 1.25wt%.

[0223] The concrete substrate was ultrasonically treated in anhydrous ethanol for 15 min, then washed with deionized water, and dried to obtain a pretreated concrete substrate.

[0224] The inducer solution was added dropwise to the pretreated concrete substrate, and then spin-coated at 1000 rpm for 15 s, then spin-coated at 3500 rpm for 45 s, and then the spin-coating was stopped, to obtain a substrate / induction layer.

[0225] Then the substrate / induction layer was placed in the third precursor solution, and then the fourth precursor solution was added dropwise, and the second precursor solution was added dropwise for 12 h; the obtained substrate sample was taken out, washed with deionized water, and dried to obtain a substrate / induction layer / mineralization layer.

[0226] The obtained substrate / induction layer / mineralization layer was subjected to microhardness testing, and the hardness was 63.27 HV.

[0227] The obtained substrate / induction layer / mineralization layer was subjected to 7-day electrochemical impedance spectroscopy testing, and the impedance was 5.61 x 10 3 Ω·cm 2 .

[0228] The strength and corrosion resistance of the obtained coating were tested by GB / T 9790-2020 (hardness) and GB / T 24196-2009 (EIS), and the results are shown in Table 1.

[0229] Table 1: Performance test results of the coating obtained in the examples and comparative examples

[0230] Strength / Unit Corrosion Resistance Example 1 165.3 HV 6.53 x 10 5 Ω·cm 2 ]]> Example 2 145.3 HV <![CDATA[3.73×10 5 Ohm cm 2 ]]> Example 3 132.4 HV 2.14 x 10 5 Ω·cm 2 ]]> Example 4 151.9 HV 3.65 x 10 5 Ω·cm 2 ]]> Example 5 103.78 HV 9.32 x 10 4 Ω·cm 2 ]]> Comparative Example 1 96.43 HV 7.91 x 10 4 Ω·cm 2 ]]> Comparative Example 2 No complete coating formed No complete coating formed Comparative Example 3 87.56 HV 3.75 x 10 4 Ω·cm 2 ]]> Comparative Example 4 63.27 HV 5.61 x 10 3 Ω·cm 2 ]]>

[0231] From Table 1, it can be seen that:

[0232] 1. By comparing the examples with the comparative examples, it is shown that by precisely controlling the concentrations of the components and the process parameters, a coating with a dense structure can be formed, and the hardness and corrosion resistance of the concrete can be simultaneously improved.

[0233] 2. The role of magnesium ions

[0234] Comparative Example 1: When the content of magnesium chloride in the third precursor solution reaches 0.20 wt%, the hardness is only 96.43 HV, and the impedance decreases to 7.91 x 10 4 Ω·cm 2 , which is significantly lower than that of the examples. The reason is that excessive magnesium ions replace calcium ions in the calcium carbonate crystal to form lattice defects, resulting in a loose structure of the mineralization layer. In Example 1, the magnesium ion concentration is at the optimal dosage, and the mineralization layer presents a shell-shaped tessellation polygon structure, with nanoparticles tightly packed, which proves that appropriate amounts of magnesium ions can adjust crystal growth, control the structure of the coating, and improve the mechanical properties.

[0235] 3. The role of polyacrylic acid

[0236] Comparative Example 2: When the concentration of polyacrylic acid (PAA) in the third precursor solution is reduced, the calcium ions cannot be effectively chelated, resulting in the deposition of calcium carbonate particles in a disordered manner, and the coating has an incomplete disc-like structure. In Example 1, the PAA concentration is at the optimal doping amount, and the -COOH groups attract calcium ions through electrostatic attraction, locally increasing the ion concentration and inducing uniform mineralization.

[0237] 4. Role of the base layer

[0238] Example 5: After omitting the base layer, the hardness decreases to 103.78 HV, and the impedance is 9.32 x 10 4 Ω·cm 2 , which is much lower than that of Example 1. The surface of the base layer has many active sites, allowing the functional material to be embedded through chemical bonding and interfacial action. The base layer also prevents the growth of the coating in a disordered manner, and its absence can lead to uneven thickness and reduced density of the mineralized layer.

[0239] 5. Role of the organic-functional material layer

[0240] Comparative Example 3: Without adding the organic-functional material layer, the hardness is 87.56 HV, and the impedance is 3.75 x 10 4 Ω·cm 2 . The functional material in the organic-functional material layer can act as a rigid skeleton to hinder crack propagation, and the structure of the material increases the diffusion path of the corrosion medium. The organic-functional material layer has a large specific surface area, providing more active sites for the growth of inorganic crystals in the mineralized layer, which together with the dense calcium carbonate in the mineralized layer forms a "multiple effect". The functional material loaded with functional additives can further enhance its functionality by releasing corrosion inhibitors, lubricants, repair agents, and rust inhibitors.

[0241] 6. Synergistic protection effect of the multi-layer structure

[0242] Comparative Example 4: Only the induction layer + mineralized layer, hardness 63.27 HV, impedance 5.61 x 10 3 Ω·cm 2 , which proves that the protective performance of the mineralized layer is significantly reduced without the organic-functional material layer and the base layer. The multi-layer structure in the example achieves the optimization of hardness and corrosion resistance through interfacial synergy.

[0243] The above-described preferred embodiments of the present application should be noted that for those skilled in the art, without departing from the principles of the present application, can make several improvements and refinements, these improvements and refinements should be considered as the protection scope of the present application.

Claims

1. A protective coating, characterized in that: It includes an induction layer, an organic-functional material layer and a mineralization layer stacked in sequence on a substrate; The functional material in the organic-functional material layer is a two-dimensional sheet material and / or a granular material; The material of the mineralized layer is calcium phosphate or calcium carbonate.

2. The protective coating according to claim 1, characterized in that A base layer is provided between the induction layer and the organic-functional material layer, and the base layer is made of calcium phosphate or calcium carbonate.

3. The protective coating according to claim 1, characterized in that The induction layer, the organic-functional material layer and the mineralization layer are arranged in a periodic manner.

4. The method for preparing the protective coating according to any one of claims 1 to 3, characterized in that: The following steps are involved: preparing an induction layer on a substrate to obtain a substrate / induction layer; preparing an organic-functional material layer on the inductive layer of the substrate / inductive layer to obtain a substrate / inductive layer / organic-functional material layer; preparing a mineralized layer on the organic-functional material layer of the substrate / induction layer / organic-functional material layer to obtain the protective coating; The preparation of the mineralized layer comprises the following steps: placing the substrate / induction layer / organic-functional material layer into a third precursor solution, and then dropwise adding a fourth precursor solution; The third precursor solution includes a calcium salt, an ion traction agent, and a crystal form modifier; and the fourth precursor solution includes a carbonate or a phosphate.

5. The preparation method according to claim 4, characterized in that The preparation of the induction layer comprises the following steps: applying an inducer solution on a substrate; the inducer in the inducer solution is an organic substance containing amino groups and / or hydroxyl groups; the organic substance containing amino groups and / or hydroxyl groups is a polymer or a bio-based material; The polymer comprises one or more of epoxy resin, polyurethane, polylactic acid, polyvinyl alcohol, polyethylene glycol, polylysine, polyimide, polybenzimidazole, polyacrylamide, polyethyleneimine, polyhydroxyalkanoate, polybutylene succinate, polyethylene furandicarboxylate and amphiphilic block copolymer, wherein the amphiphilic block copolymer comprises polyvinyl alcohol-polyacrylic acid; The bio-based material comprises one or more of chitosan, chitosan derivatives, starch, starch derivatives, cellulose, cellulose derivatives, sodium alginate, collagen, silk protein, gelatin and chitin; The mass concentration of the inducer solution is 0.25-1.5%.

6. The preparation method according to claim 4, characterized in that When a base layer is provided between the induction layer and the organic-functional material layer, the method further comprises: preparing a base layer on the induction layer of the substrate / induction layer; The preparation of the base layer comprises the following steps: placing the base / induction layer into a first precursor solution, and then dropwise adding a second precursor solution; The first precursor solution includes a calcium salt and an ion puller, wherein the ion puller includes one or more of oxalic acid, malonic acid, succinic acid, adipic acid, lactic acid, malic acid, tartaric acid, citric acid, salicylic acid, glycine, alanine, glutamic acid, benzoic acid, sodium acetate, sodium citrate, aspartic acid, phthalic acid, p-aminobenzoic acid, polyacrylic acid, polymethacrylic acid, and sodium polyacrylate; the second precursor solution includes carbonate or phosphate; In the first precursor solution, the calcium salt includes one or more of calcium chloride, calcium nitrate, calcium acetate, calcium bromide, calcium iodide, calcium formate, calcium propionate, calcium butyrate, calcium lactate, calcium sulfate, calcium chlorate, calcium chlorite, calcium perchlorate, calcium thiocyanate, calcium glycerophosphate, calcium dihydrogen phosphate, calcium gluconate and calcium dithionite, and the mass concentration of the calcium salt is 0.25-1.5%; the mass concentration of the ion traction agent is 1.25×10 -3 ~2.25×10 -3 %; In the second precursor solution, the carbonate is provided by one or more of lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, cesium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, rubidium bicarbonate, cesium bicarbonate, ammonium bicarbonate, methylamine carbonate, calcium bicarbonate, magnesium bicarbonate, barium bicarbonate, zinc bicarbonate, iron bicarbonate, aluminum bicarbonate, ethylenediamine carbonate, dimethyl carbonate and ethylene carbonate; the phosphate is provided by one or more of lithium phosphate, sodium phosphate, potassium phosphate, beryllium phosphate, calcium phosphate, trisodium phosphate, tripotassium phosphate, triammonium phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, calcium dihydrogen phosphate, ammonium dihydrogen phosphate, dipotassium hydrogen phosphate, disodium hydrogen phosphate, diammonium hydrogen phosphate and triethyl phosphate; and the mass concentrations of the carbonate and phosphate are independently 0.25-1.5%; The second precursor solution is added dropwise within 8 to 24 hours.

7. The preparation method according to claim 4, characterized in that The preparation of the organic-functional material layer comprises: applying an organic-functional material composite system on the inductive layer of the substrate / inductive layer; The organic-functional material composite system includes an inducer and a functional material; The functional material is a two-dimensional sheet material and / or a granular material; The two-dimensional sheet material includes one or more of zirconium phosphate, intercalated zirconium phosphate, hydrotalcite compounds, hydrotalcite-like compounds, hexagonal boron nitride, graphene sheets, graphite intercalation compounds, graphene oxide, graphyne, graphitic carbon nitride, bismuth bromide, lead iodide, cadmium sulfide, indium selenide, bismuth telluride, niobium telluride, molybdenum disulfide, tungsten diselenide, tungsten ditelluride, niobium diselenide, titanium diselenide, molybdenum dioxide, vanadium dioxide, TMDs, MXenes, Xenes, two-dimensional MOFs and two-dimensional COFs; The particulate material includes one or more of calcium carbonate, silicon oxide, silicon carbide, silicon nitride, aluminum oxide, magnesium oxide, aluminum nitride, boron nitride, titanium diboride, corundum, pumice, zeolite, volcanic rock, sepiolite, polyethylene particles, polypropylene particles, activated carbon and aerogel particles; In the organic-functional material composite system, the mass concentration of the inducer is 0.25-1.5%, and the mass concentration of the functional material is 0.05-0.75%.

8. The preparation method according to claim 4, characterized in that In the third precursor solution, the calcium salt includes one or more of calcium chloride, calcium nitrate, calcium acetate, calcium bromide, calcium iodide, calcium formate, calcium propionate, calcium butyrate, calcium lactate, calcium sulfate, calcium chlorate, calcium chlorite, calcium perchlorate, calcium thiocyanate, calcium glycerophosphate, calcium dihydrogen phosphate, calcium gluconate and calcium dithionite, and the mass concentration of the calcium salt is 0.35-2.5%; the ion traction agent includes one or more of oxalic acid, malonic acid, succinic acid, adipic acid, lactic acid, malic acid, tartaric acid, citric acid, salicylic acid, glycine, alanine, glutamic acid, benzoic acid, sodium acetate, sodium citrate, aspartic acid, phthalic acid, p-aminobenzoic acid, polyacrylic acid, polymethacrylic acid and sodium polyacrylate, and the mass concentration of the ion traction agent is 1.5×10 -3 ~2.5×10 -3 %; the crystal form modifier includes one or more of a soluble salt, an organic compound modifier and a biomolecule modifier; the soluble salt includes one or more of magnesium chloride, strontium chloride, barium chloride, ammonium chloride, magnesium sulfate, aluminum sulfate, zinc sulfate, sodium sulfate, potassium sulfate, sodium carbonate, magnesium nitrate, strontium nitrate, barium nitrate, ammonium nitrate, sodium phosphate and sodium tripolyphosphate; the organic compound modifier includes one or more of ethylene glycol, glycerol, cetyltrimethylammonium bromide, sodium lauryl sulfate, hydroxyethylidene diphosphonic acid, ethylenediamine tetramethylenephosphonic acid, glycerol, sorbitol, polyethylene glycol, polyvinyl alcohol and polyvinyl pyrrolidone; the biomolecule modifier includes one or more of oxalic acid, glutamic acid, citric acid, malic acid, tartaric acid, succinic acid, glycine, aspartic acid, polysaccharide, casein, chitin, chitin, heparin, carbonic anhydrase, lipase and protease; the mass concentration of the crystal form modifier is 0.04-0.14%; In the fourth precursor solution, the carbonate is provided by one or more of lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, cesium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, rubidium bicarbonate, cesium bicarbonate, ammonium bicarbonate, methylamine carbonate, calcium bicarbonate, magnesium bicarbonate, barium bicarbonate, zinc bicarbonate, iron bicarbonate, aluminum bicarbonate, ethylenediamine carbonate, dimethyl carbonate and ethylene carbonate; the phosphate is provided by one or more of lithium phosphate, sodium phosphate, potassium phosphate, beryllium phosphate, calcium phosphate, trisodium phosphate, tripotassium phosphate, triammonium phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, calcium dihydrogen phosphate, ammonium dihydrogen phosphate, dipotassium hydrogen phosphate, disodium hydrogen phosphate, diammonium hydrogen phosphate and triethyl phosphate; and the mass concentrations of the carbonate and phosphate are independently 0.35 to 2.5 wt%; The fourth precursor solution is added dropwise within 12 to 36 hours.

9. The preparation method according to claim 4, characterized in that After the mineralized layer is prepared, the method further includes repeating the process of sequentially preparing an induction layer, an organic-functional material layer and a mineralized layer on the mineralized layer.

10. Use of the protective coating according to any one of claims 1 to 3 or the protective coating prepared by the preparation method according to any one of claims 4 to 9 in the protection of metal materials, ceramic materials, polymer materials and cement materials.

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