A graphene-modified concrete surface protection material

Abstract

This invention provides a graphene-modified concrete surface protective material, comprising a separately stored inner coating and modified graphene. The inner coating is obtained by dispersing inorganic nanoparticles and graphene in cement and adding a defoamer for defoaming. The modified graphene is obtained by surface modification of graphene with a modifier prepared from silica microspheres, chain extenders, inorganic nanoparticles, and water. When this surface protective material is used on the surface of concrete components, it can improve their mechanical properties, corrosion resistance, and extend the service life of the concrete components.

Description

Technical Field

[0001] This invention relates to the field of water-based environmentally friendly coatings technology, specifically to a graphene-modified concrete surface protective material, coating, and its preparation method. Background Technology

[0002] Cement-based materials play a vital role in national infrastructure and major engineering projects. Dam projects are characterized by high water head, high discharge volume, and high discharge velocity. Due to long-term exposure to the natural environment, concrete materials are susceptible to carbonization, microbial erosion, and pollution from harmful substances in the air, severely impacting their durability and aesthetics. Therefore, the research and development of protective materials for concrete surfaces is urgently needed. Existing concrete surface protective materials are mainly organic polymer coatings, including epoxy, acrylic, and silane types. These materials suffer from high costs, low outdoor aging resistance, poor corrosion resistance, high maintenance costs, and poor interfacial bonding with cement-based materials. They are also prone to separation from the concrete matrix due to water flow impact and cannot achieve the same lifespan as the building structure.

[0003] The preparation of graphene-cement-based composite materials has become a hot topic in scientific research and application in recent years. However, the low compatibility between graphene and concrete remains a key issue both domestically and internationally in the preparation, application, and industrialization of graphene-cement-based materials. Summary of the Invention

[0004] To address the problems existing in the background art, the present invention provides a graphene-modified concrete surface protective material, a coating, and a method for preparing the same. When this surface protective material is used on the surface of concrete components, it can improve their mechanical properties, corrosion resistance, and extend the service life of the concrete components.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0006] In a first aspect, the present invention provides a graphene-modified concrete surface protection material, comprising an inner coating layer and modified graphene stored separately. The inner coating layer is obtained by dispersing inorganic nanoparticles and graphene in cement and adding a defoamer for defoaming. The modified graphene is obtained by surface modification of graphene with a modifier prepared from silica microspheres, chain extenders, inorganic nanoparticles and water.

[0007] Specifically, silica microspheres and chain extenders are first added to water for condensation assembly. Then, inorganic nanoparticles are added and mixed evenly. The silica microspheres and chain extenders are assembled through hydrogen bonds, and then assembled with the inorganic nanoparticles through hydrogen bonds to form a modifier. The modifier modifies the graphene surface, and the inorganic nanoparticles are grafted onto the graphene surface, thereby enhancing mechanical properties while effectively blocking the penetration of corrosive and harmful substances.

[0008] According to the above scheme, the mass ratio of inorganic particles, graphene, cement and defoamer in the inner coating is 20~60:0.1~1:100:0.1~0.3.

[0009] According to the above scheme, the amount of graphene in the modified graphene is 10 wt% to 100 wt% of the modifier, the mass ratio of silica microspheres, chain extender and inorganic nanoparticles in the modifier is 20 to 60: 10 to 30: 100, and the mass fraction of inorganic nanoparticles in the modifier is 10 to 30%.

[0010] According to the above scheme, the particle size of the silica microspheres is 0.1-0.5 μm, and the chain extender is hydroxyl-terminated polydimethylsiloxane, methylphenyldiethoxysilane, or phenyltriethoxysilane.

[0011] According to the above scheme, the graphene is one or more of single-layer graphene, multi-layer graphene, or graphene oxide, and the inorganic nanoparticles are one or more of montmorillonite, attapulgite, TiO2, or Al2O3.

[0012] Secondly, the present invention provides a graphene-modified concrete surface protective coating prepared from the above-mentioned graphene-modified concrete surface protective material, comprising an inner coating and an outer coating. The inner coating is obtained by applying the inner coating material to the surface of the concrete component, and the outer coating is obtained by spraying the modified graphene onto the inner coating.

[0013] Furthermore, the thickness of the inner coating is 0.2~0.6 mm, and the thickness of the outer coating is 0.4~0.6 mm.

[0014] Thirdly, the present invention provides a method for preparing the above-mentioned graphene-modified concrete surface protective coating, comprising the following steps:

[0015] S1. Silica microspheres and chain extenders are condensed and assembled in water, and inorganic nanoparticles are added and mixed evenly to obtain a modifier;

[0016] S2. Mix the modifier with graphene, stir in a constant temperature water bath, and disperse ultrasonically to obtain modified graphene;

[0017] S3. Disperse inorganic nanoparticles and graphene in water using ultrasonication, add cement and stir, then add defoamer and let stand to defoam, to obtain the inner coating layer;

[0018] S4. Apply the inner coating to the surface of the concrete component. When it is semi-dry, spray modified graphene. After curing, the graphene-modified concrete surface protective coating is obtained.

[0019] According to the above scheme, the reaction temperature in step S1 is 40~80 ℃, the time for the condensation assembly of silica microspheres and chain extender is 1~2 h, the reaction time after adding inorganic nanoparticles is 2~3 h, the reaction temperature in step S2 is 20~40 ℃, and the reaction time is 1~3 h.

[0020] According to the above scheme, in step S4, the spraying time is 4~6 s, the spray gun moving speed is 20~30 cm / s, the spray gun diameter is 180~220 mm, the spray thickness is controlled at 0.4~0.6 mm, and the dosage is approximately 0.98~1.06 L / m. 2 .

[0021] Modified graphene was prepared by modifying graphene with a modifier. The chain extender acted as a "bridge," enabling a strong chemical bond between silica microspheres and inorganic nanoparticles. The inorganic nanoparticles adsorbed and deposited on the graphene surface through hydrogen bonding with oxygen-containing functional groups. Together, the silica microspheres and inorganic nanoparticles formed a physical barrier, increasing the interlayer spacing of the graphene and preventing flocculation and aggregation. Simultaneously, the sheet-like barrier effect of the nanoparticles effectively inhibited deoxygenation and deprotonation of graphene under highly alkaline conditions, preventing cross-linking between the outer graphene layer and harmful ions and extending the coating's lifespan. Furthermore, the silica microspheres formed a three-dimensional structure, providing synergistic reinforcement. Coating the graphene sheets, they created numerous tortuous sheets that blocked contact between corrosive media and the substrate, thus mitigating the erosion of the substrate.

[0022] The inner coating exhibits good interfacial compatibility with the cement and concrete substrate, enabling it to adhere tightly to the component surface for a long period. The inner and outer coatings are separated by the -COO groups on the graphene surface. - Na between inorganic nanoparticle layers + The stability of the coating structure is maintained by a combination of electrostatic adsorption and van der Waals forces between graphene sheets.

[0023] Compared with existing technologies, the graphene-modified concrete surface protection material and coating of the present invention have the following beneficial effects:

[0024] 1. The protective coating of the present invention adopts a layered structure design concept. The inner coating can provide strength and increase the adhesion of the coating. The outer coating is formed by the parallel orientation distribution and stacking of modified graphene to form a dense stacked orientation structure of graphene, which can improve the protective performance of the coating, effectively prevent the erosion of corrosive substances, extend the service life of concrete components, and achieve a strengthening effect in the direction perpendicular to the orientation.

[0025] 2. Modified graphene in the outer coating: By grafting inorganic nanoparticles onto the surface of graphene, the mechanical properties are enhanced while effectively blocking the penetration of corrosive and other harmful substances, thus extending the service life of concrete components.

[0026] 3. The protective coating of the present invention has excellent mechanical and chemical stability and can be widely used in aerospace, petrochemical, marine shipbuilding and other fields to extend the service life of concrete buildings and reduce maintenance costs. Attached Figure Description

[0027] Figure 1 This is a schematic diagram illustrating the preparation steps and structure of the graphene-modified concrete surface protective coating of the present invention.

[0028] Figure 2 The chloride ion concentration changes in concrete test blocks in Examples 1-4 and Comparative Examples 1 and 2 of this invention;

[0029] Figure 3 The compressive strength of the concrete test blocks in Examples 1-4 and Comparative Examples 1 and 2 of this invention. Detailed Implementation

[0030] The principles and features of the present invention are described below with reference to the accompanying drawings and specific embodiments. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0031] It should be noted that, in the description of the embodiments of this application, the term "some specific embodiments" means that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same implementation or instance. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0032] In a first aspect, the present invention provides a graphene-modified concrete surface protection material, comprising an inner coating layer and modified graphene stored separately. The inner coating layer is obtained by dispersing inorganic nanoparticles and graphene in cement and adding a defoamer for defoaming. The modified graphene is obtained by surface modification of graphene with a modifier prepared from silica microspheres, chain extenders, inorganic nanoparticles and water.

[0033] In some specific embodiments, the mass ratio of inorganic nanoparticles, graphene, cement and defoamer in the inner coating is 20~60:0.1~1:100:0.1~0.3. Specifically, in some preferred embodiments of the present invention, the mass ratio of inorganic nanoparticles, graphene and cement is 40:0.5:100:0.2.

[0034] In some specific embodiments, the amount of graphene in the modified graphene is 10 wt% to 100 wt% of the modifier, the mass ratio of silica microspheres, chain extender, and inorganic nanoparticles in the modifier is 20-60:10-30:100, and the mass fraction of inorganic nanoparticles in the modifier is 10-30%. Specifically, in some preferred embodiments of the present invention, the amount of graphene is 50 wt% of the modifier, and the mass ratio of silica microspheres, chain extender, and inorganic nanoparticles is 40:20:100.

[0035] In some specific embodiments, the silica microspheres have a particle size of 0.1-0.5 μm, and the chain extender is hydroxyl-terminated polydimethylsiloxane, methylphenyldiethoxysilane, or phenyltriethoxysilane.

[0036] In some specific embodiments, the graphene is one or more of single-layer graphene, multi-layer graphene, or graphene oxide, and the inorganic nanoparticles are one or more of montmorillonite, attapulgite, TiO2, or Al2O3.

[0037] Secondly, the present invention provides a graphene-modified concrete surface protective coating prepared from the above-mentioned graphene-modified concrete surface protective material, comprising an inner coating and an outer coating. The inner coating is obtained by applying the inner coating material to the surface of the concrete component, and the outer coating is obtained by spraying the modified graphene onto the inner coating.

[0038] Furthermore, the thickness of the inner coating is 0.2~0.6 mm, and the thickness of the outer coating is 0.4~0.6 mm.

[0039] Thirdly, such as Figure 1 As shown, the present invention provides a method for preparing the above-mentioned graphene-modified concrete surface protective material, comprising the following steps:

[0040] S1. Silica microspheres and chain extenders are condensed and assembled in water, and inorganic nanoparticles are added and mixed evenly to obtain a modifier;

[0041] S2. Mix the modifier with graphene, stir in a constant temperature water bath, and disperse ultrasonically to obtain modified graphene;

[0042] S3. Disperse inorganic nanoparticles and graphene in water using ultrasonication, add cement and stir, then add defoamer and let stand to defoam, to obtain the inner coating layer;

[0043] S4. Apply the inner coating to the surface of the concrete component. When it is semi-dry, spray modified graphene. After curing, the graphene-modified concrete surface protective coating is obtained.

[0044] In some specific embodiments, the mass fraction of inorganic nanoparticles in the inner coating layer in step S3 is 20~60 wt%.

[0045] Further, in step S1, the reaction temperature is 40~80 ℃, the assembly time of silica microspheres and chain extender through polycondensation is 1~2 h, and the reaction time after adding inorganic nanoparticles is 2~3 h. Specifically, in some preferred embodiments of the present invention, the reaction temperature is 60 ℃, the assembly time of silica microspheres and chain extender through polycondensation is 1.5 h, and the reaction time after adding inorganic nanoparticles is 2.5 h; in step S2, the reaction temperature is 20~40 ℃, and the reaction time is 1~3 h. Specifically, in some preferred embodiments of the present invention, the reaction temperature is 30 ℃, and the reaction time is 2 h.

[0046] Furthermore, the stirring speed used in step S1 is 200-400 r / min, and the stirring speed used in step S2 is 200-500 r / min.

[0047] In some specific embodiments, in step S4, the spraying time is 4-6 seconds, the spray gun moving speed is 20-30 cm / s, the spray gun nozzle diameter is 180-220 mm, the spray thickness is controlled at 0.4-0.6 mm, and the dosage is approximately 0.98-1.06 L / m. 2 .

[0048] Preferably, in step S4, the spraying time is 5 s, the spray gun moving speed is 25 cm / s, the spray gun nozzle diameter is 200 mm, the spraying thickness is controlled at 0.5±0.05 cm / s, and the dosage is approximately 1.02 L / m. 2 .

[0049] Based on the above embodiments, the present invention provides the following specific examples to further illustrate the invention. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following examples, unless otherwise specified, are generally performed according to the manufacturer's recommended conditions. Unless otherwise stated, percentages and parts are calculated by mass.

[0050] Example 1

[0051] Two g of silica microspheres and one g of polydimethylsiloxane were added to 50 g of deionized water, heated in a 60 °C water bath, and stirred at 300 r / min for 1.5 h. Then, 10 g of montmorillonite was added and the reaction continued for another 2.5 h to obtain the modifier. One g of the modifier was mixed with 0.2 g of graphene, stirred in a 30 °C water bath for 2 h, and ultrasonically dispersed for 5 min to obtain silica-modified graphene.

[0052] First, 20 g of montmorillonite and 0.2 g of graphene were added to 50 g of water and mechanically stirred for 5 min, then sonicated for 15 min. Next, 100 g of cement was added and mechanically stirred for 5 min. Then, 0.1 g of defoamer was added and allowed to stand to defoam, forming the inner coating. This inner coating was then applied to the cleaned surface of a 40 cm × 40 cm × 40 cm concrete sample block to form the inner coating layer. The thickness of the inner coating layer was controlled at 0.4 ± 0.05 mm. When it was semi-dry, modified graphene was sprayed on as the outer coating layer. After curing at room temperature, the graphene-modified concrete surface protective coating was obtained. The coating thickness was controlled at 0.5 ± 0.05 mm, and the dosage was approximately 1.02 L / m². 2 .

[0053] Example 2

[0054] Two g of silica microspheres and two g of polydimethylsiloxane were added to 50 g of deionized water, heated in a 60 ℃ water bath, and stirred at 300 r / min for 1.5 h. Then, 10 g of montmorillonite was added and the reaction continued for another 2.5 h to obtain the modifier. One g of the modifier was mixed with 0.4 g of graphene, stirred in a 30 ℃ constant temperature water bath for 2 h, and ultrasonically dispersed for 10 min to obtain silica-modified graphene.

[0055] First, 40 g of montmorillonite and 0.2 g of graphene were added to 50 g of water and mechanically stirred for 5 min, then sonicated for 15 min. Next, 100 g of cement was added and mechanically stirred for 5 min. Then, 0.1 g of defoamer was added and allowed to stand to defoam, forming the inner coating. This inner coating was applied to the cleaned surface of a 40 cm × 40 cm × 40 cm concrete specimen to form the inner coating layer. The thickness of the inner coating layer was controlled at 0.4 ± 0.05 mm. When it was semi-dry, modified graphene was sprayed on as the outer coating layer. After curing at room temperature, the graphene-modified concrete surface protective coating was obtained. The thickness of the outer coating layer was controlled at 0.5 ± 0.05 mm, with a dosage of approximately 1.02 L / m². 2 .

[0056] Example 3

[0057] 4 g of silica microspheres and 2 g of polydimethylsiloxane were added to 50 g of deionized water, heated in a 60 ℃ water bath, and stirred at 300 r / min for 1.5 h. Then, 10 g of montmorillonite was added and the reaction continued for 2.5 h to obtain the modifier. 1 g of the modifier was mixed with 0.5 g of graphene, stirred in a 30 ℃ constant temperature water bath for 2 h, and ultrasonically dispersed for 10 min to obtain modified graphene.

[0058] First, 40 g of montmorillonite and 0.5 g of graphene were added to 50 g of water and mechanically stirred for 5 min, then sonicated for 15 min. Next, 100 g of cement was added and mechanically stirred for 5 min. Then, 0.2 g of defoamer was added and allowed to stand to defoam, forming the inner coating. This inner coating was applied to the cleaned surface of a 40 cm × 40 cm × 40 cm concrete specimen to form the inner coating layer. The thickness of the inner coating layer was controlled at 0.4 ± 0.05 mm. When it was semi-dry, modified graphene was sprayed on as the outer coating layer. After curing at room temperature, the graphene-modified concrete surface protective coating was obtained. The thickness of the outer coating layer was controlled at 0.5 ± 0.05 mm, with a dosage of approximately 1.02 L / m². 2 .

[0059] Example 4

[0060] Six g of silica microspheres and four g of phenyltriethoxysilane were added to 50 g of deionized water, heated in a 60 ℃ water bath, and stirred at 300 r / min for 1.5 h. Then, 10 g of montmorillonite was added and the reaction continued for another 2.5 h to obtain the modifier. One g of the modifier was mixed with 0.8 g of graphene, stirred in a 30 ℃ constant temperature water bath for 2 h, and ultrasonically dispersed for 10 min to obtain modified graphene.

[0061] First, 60 g of montmorillonite and 1 g of graphene were added to 50 g of water and mechanically stirred for 5 min, then sonicated for 15 min. Next, 100 g of cement was added and mechanically stirred for 5 min. Then, 0.3 g of defoamer was added and allowed to stand to defoam, forming the inner coating. This inner coating was applied to the cleaned surface of a 40 cm × 40 cm × 40 cm concrete specimen to form the inner coating layer. The thickness of the inner coating layer was controlled at 0.4 ± 0.05 mm. When it was semi-dry, modified graphene was sprayed on as the outer coating layer. After standing and curing at room temperature, the graphene-modified concrete surface protective coating was obtained. The thickness of the outer coating layer was controlled at 0.5 ± 0.05 mm, with a dosage of approximately 1.02 L / m². 2 .

[0062] Comparative Example 1

[0063] Add 50 g of water to 100 g of cement and stir at high speed for 5 min. Pour the mixture into a 40 cm × 40 cm × 40 cm mold and allow it to cure at room temperature for 1 day before demolding to obtain a cement paste test block. No coating is applied as Comparative Example 1.

[0064] Comparative Example 2

[0065] First, 20 g of montmorillonite and 0.2 g of graphene were added to 50 g of water and mechanically stirred for 5 min, then sonicated for 15 min. Next, 100 g of cement was added and mechanically stirred for 5 min. Then, 0.1 g of defoamer was added and allowed to stand to defoam, forming the inner coating. This inner coating was then applied to the cleaned surface of a 40 cm × 40 cm × 40 cm concrete specimen to form the inner coating layer. The thickness of the inner coating layer was controlled at 0.4 ± 0.05 mm. When it was semi-dry, graphene was sprayed on as the outer coating layer. After curing at room temperature, the graphene-modified concrete surface protective coating was obtained. The thickness of the outer coating layer was controlled at 0.5 ± 0.05 mm, with a dosage of approximately 1.02 L / m². 2 .

[0066] 1. The chloride ion permeability in concrete specimens with graphene-modified concrete surface protective coatings obtained in Examples 1-4, concrete specimens without coating in Comparative Example 1, and concrete specimens with graphene-modified concrete surface protective coatings obtained in Comparative Example 2 were measured by forming silver chloride precipitates.

[0067] The specific test method is as follows: Filter paper soaked in 5% NaCl solution is placed on the surface of the concrete sample, and the sample is repeatedly soaked several times, each time for 3 hours, maintaining the soaking state for 48 hours. Then, the sample surface is cleaned, dried, and cut. Samples are collected from different parts of the sample block, ground into powder, and added to 50 ml of deionized water, then ultrasonically dispersed for 30 minutes. A titration test is then performed using silver nitrate solution, and the concentration of free chloride ions in the liquid is calculated using the equation C. Cl- =C AgNO3 V1V3M Cl- / V2m p ×100%, where C Cl− It is the percentage (%) of free chloride ions in the powder, C AgNO3 V1 is the millimolecular concentration (mmol / mL) of the silver nitrate solution, V2 is the volume of the silver nitrate solution (mL), V3 is the volume of liquid required for titration (mL), and M is the volume of deionized water used to dissolve the powder (mL). Cl- It is the molar mass of chloride ions (g / mmol), m p It refers to the powder mass (g).

[0068] The results are shown in Table 1 below. Figure 2 As shown.

[0069] Table 1 Chloride ion concentration of concrete test blocks

[0070] Depth (mm) Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Example 4 5 0.5 0.39 0.29 0.26 0.18 0.23 10 0.38 0.32 0.24 0.22 0.10 0.16 15 0.30 0.24 0.18 0.15 0.04 0.08

[0071] The data above show that at different depths, the chloride ion concentration of the test blocks in Examples 1-4 is lower than that in Comparative Examples 1 and 2. The graphene-modified concrete surface protective coating of the present invention effectively prevents chloride ions from penetrating into the cement matrix, and the graphene in the outer coating has a better protective effect against chloride ion corrosion after modification.

[0072] 2. The 3-day and 28-day compressive strengths of concrete specimens with graphene-modified concrete surface protective coatings obtained in Examples 1-4, concrete specimens without coating in Comparative Example 1, and concrete specimens with graphene-modified concrete surface protective coatings obtained in Comparative Example 2 were measured. The results are shown in Table 2 and... Figure 3 As shown.

[0073] Table 2

[0074] Maintenance time (d) Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Example 4 3 25.12 29.64 32.07 35.57 41.29 38.66 28 42.25 48.78 51.62 54.41 60.20 58.28

[0075] The above data proves that the protective coating prepared by the protective material of the present invention can improve the compressive strength of the component.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A graphene-modified protective coating for concrete surfaces, characterized in that, It includes an inner coating and an outer coating, wherein the inner coating is obtained by applying an inner layer of paint to the surface of a concrete component, and the outer coating is obtained by spraying modified graphene onto the inner coating; The inner coating is obtained by dispersing inorganic nanoparticles and graphene in cement and adding a defoamer to defoam; The modified graphene is obtained by surface modification of graphene with a modifier made of silica microspheres, chain extender, inorganic nanoparticles and water. The chain extender is hydroxyl-terminated polydimethylsiloxane, methylphenyldiethoxysilane or phenyltriethoxysilane. The inorganic nanoparticles are one or more of montmorillonite, attapulgite, TiO2 or Al2O3.

2. The graphene-modified concrete surface protective coating according to claim 1, characterized in that, The mass ratio of inorganic nanoparticles, graphene, cement, and defoamer in the inner coating is 20~60:0.1~1:100:0.1~0.

3.

3. The graphene-modified concrete surface protective coating according to claim 1, characterized in that, The amount of graphene used in the modified graphene is 10 wt% to 100 wt% of the modifier. The mass ratio of silica microspheres, chain extender and inorganic nanoparticles in the modifier is 20 to 60: 10 to 30:

100. The mass fraction of inorganic nanoparticles in the modifier is 10 to 30%.

4. The graphene-modified concrete surface protective coating according to claim 3, characterized in that, The silica microspheres have a particle size of 0.1-0.5 μm.

5. The graphene-modified concrete surface protective coating according to any one of claims 1 to 4, characterized in that, The graphene is one or more of single-layer graphene, multi-layer graphene, or graphene oxide.

6. The graphene-modified concrete surface protective coating according to claim 1, characterized in that, The thickness of the inner coating is 0.2~0.6 mm, and the thickness of the outer coating is 0.4~0.6 mm.

7. The method for preparing the graphene-modified concrete surface protective coating according to any one of claims 1-5, characterized in that, Includes the following steps: S1. Silica microspheres and chain extenders are condensed and assembled in water, and inorganic nanoparticles are added and mixed evenly to obtain a modifier; S2. The modifier is mixed with graphene, stirred in a constant temperature water bath, and ultrasonically dispersed to obtain modified graphene; S3. Disperse inorganic nanoparticles and graphene in water using ultrasonication, add cement and stir, then add defoamer and let stand to defoam, to obtain the inner coating layer; S4. Apply the inner coating to the surface of the concrete component. When it is semi-dry, spray modified graphene. After curing, the graphene-modified concrete surface protective coating is obtained.

8. The preparation method according to claim 7, characterized in that, In step S1, the reaction temperature is 40~80 ℃, the time for the silica microspheres and chain extender to condense and assemble is 1~2 h, and the reaction time after adding inorganic nanoparticles is 2~3 h. In step S2, the reaction temperature is 20~40 ℃, and the reaction time is 1~3 h.

9. The preparation method according to claim 7, characterized in that, In step S4, the spraying time is 4-6 seconds, the spray gun moving speed is 20-30 cm / s, the spray gun nozzle diameter is 180-220 mm, the spray thickness is controlled at 0.4-0.6 mm, and the dosage is approximately 0.98-1.06 L / m. 2 .

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