Antibacterial coating for concrete surface as well as preparation method and application of antibacterial coating

Abstract

The invention discloses an antibacterial coating for a concrete surface as well as a preparation method and application of the antibacterial coating, and relates to the technical field of functional polymers. The antibacterial coating for the concrete surface is prepared from the following raw materials in parts by weight: 100 parts of a monomer mixture, 0.7 to 3.1 parts of an initiator, 0.3 to 2.0 parts of a chain transfer agent and 75 to 125 parts of a solvent, wherein the monomer mixture comprises a methacrylate monomer, an acrylate monomer, sodium acrylate, a urea methacrylate monomer and a capsaicin derivative in a molar ratio of (12-60): (20-60): (2-10): (2-10): (1-5). The antibacterial coating for the concrete surface is easy to prepare and operate, low in cost and environmentally friendly, and raw materials are easy to obtain; the capsaicin derivative monomer is introduced into the antibacterial coating for the concrete surface, so that the antibacterial activity of the resin is improved, and the problem of biological fouling of a concrete structure in marine infrastructure is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of functional polymer technology, in particular to a bacteriostatic coating for concrete surface and a preparation method and application thereof. BACKGROUND

[0002] In the field of marine infrastructure construction such as marine engineering, water conservancy facilities and port construction, concrete is widely used as the main building material. However, the concrete surface is easily attached by marine organisms such as algae, bacteria and shellfish.

[0003] The bacterial attachment on the concrete surface is considered as the pioneer species of biofouling. Bacteria form biofilm by secreting extracellular polysaccharides, which provides an attachment matrix for subsequent large marine organisms such as algae and shellfish. With the growth and colonization of bacteria, the possibility of subsequent biological attachment increases, and the bacteria themselves may also cause corrosion of the concrete surface.

[0004] Traditional anti-fouling methods mostly focus on removing the attached organisms or directly killing bacteria and large organisms with strong chemical agents. However, these methods have high environmental load and short action period, which may have negative effects on the ecological environment.

[0005] Therefore, the inventors believe that how to develop a bacteriostatic material for concrete surface with bacteriostatic properties, which can be directly coated on the concrete surface during the construction of marine concrete infrastructure, can prevent microbial attachment and solve the problem of biofouling of concrete structures in marine infrastructure construction.

[0006] The information disclosed in this BACKGROUND section is only for the purpose of increasing the understanding of the background of the present application and should not be regarded as an acknowledgment or any form of suggestion that this information forms prior art that is publicly known in the field. SUMMARY

[0007] In view of the above technical problems, the present application provides a bacteriostatic coating for concrete surface and a preparation method and application thereof to solve the problems in the background art.

[0008] A bacteriostatic coating for concrete surface, the bacteriostatic coating comprises, by weight fraction, 100 parts of a monomer mixture, 0.7-3.1 parts of an initiator, 0.3-2.0 parts of a chain transfer agent, and 75-125 parts of a solvent.

[0009] The monomer mixture comprises a methacrylate monomer, an acrylic acid ester monomer, sodium acrylate, a urethane methacrylate monomer and a capsaicin derivative in a molar ratio of 12-60:20-60:2-10:2-10:1-5.

[0010] In the present application, the main role of the methacrylate monomer in preparing the coating is to change the hardness and adhesion of the bacteriostatic coating material for the concrete surface, and to improve the long-acting property of the bacteriostatic coating on the concrete surface.

[0011] In the present application, the main role of the acrylate monomer in preparing the coating is to impart flexibility to the bacteriostatic coating for the concrete surface, to improve the film-forming property, and the long-chain ester can increase the hydrophobicity of the resin.

[0012] Specifically, improving the film-forming property mainly ensures that the coating is tightly attached to the pores of the concrete to form a continuous protective layer to block the adhesion path of organisms; increasing the hydrophobicity of the resin mainly reduces the wettability of the concrete surface, reduces the adhesion of the extracellular polysaccharide (hydrophilic substance) secreted by bacteria to the surface, and at the same time inhibits the penetration of water-mediated corrosion ions.

[0013] In the present application, the methacrylate urea monomer contains polymerizable double bonds and functional groups such as urea groups and ethoxy groups. The urea group forms a urea-formaldehyde cross-linking structure, increases the cross-linking density of the coating, and thus improves the hardness, solvent resistance and anti-creeper property of the coating; the ethoxy group and the like help to improve the solubility of the resin in the solvent, promote the coating to spread more evenly on the concrete surface to form a film, and improve the film-forming quality.

[0014] In the present application, if the amount of the methacrylate monomer is less than 12 parts, the hardness of the resin cannot be well adjusted; if the amount of the methacrylate monomer is more than 60 parts, the mechanical properties of the bacteriostatic coating material for the concrete surface will be affected; therefore, the amount of the methacrylate monomer is appropriately 12-60 parts; preferably 20-50 parts, and more preferably 25-43 parts.

[0015] In the present application, if the amount of the acrylate monomer is less than 20 parts, the length and flexibility of the molecular chain of the bacteriostatic coating for the concrete surface cannot be well adjusted; if the amount of the acrylate monomer is more than 60 parts, the bacteriostatic coating material for the concrete surface of the present application will be too soft, which is not conducive to film formation; therefore, the amount of the acrylate monomer is appropriately 20-60 parts; preferably 25-50 parts, and more preferably 32-44 parts.

[0016] In the present application, if the amount of the capsaicin derivative is less than 1 part, the bacteriostatic property of the resin will be insufficient and may cause stress concentration points, reducing the mechanical strength; if the amount of the capsaicin derivative is more than 5 parts, the toughness of the bacteriostatic coating for the concrete surface will be reduced, and the transparency will be decreased. Therefore, the amount of the capsaicin derivative monomer is appropriately 1-5 parts.

[0017] Preferably, the methacrylate monomer is selected from one or more of methyl methacrylate, ethyl methacrylate, hydroxyethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate or octadecyl methacrylate.

[0018] Preferably, the acrylate monomer is selected from one or more of methyl acrylate, ethyl acrylate, hydroxyethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate or octadecyl acrylate.

[0019] Preferably, the urea methacrylate monomer is selected from one or more of ethoxylated ethylene urea methacrylate, ethylene urea ethoxylate methacrylate, and ethylene urea methacrylate.

[0020] Preferably, the capsaicin derivative is selected from one or more of a benzene ring, a phenolic hydroxyl group, and an amide group.

[0021] Preferably, the methacrylate monomer is methyl methacrylate; the acrylate monomer is butyl acrylate; the methacrylate urea monomer is ethylene urea ethoxy methacrylate; and the capsaicin derivative is an 8-methyl-N-vanillamide capsaicin derivative, the structural formula of which is shown below:

[0022]

[0023] Preferably, the initiator is selected from one or more of azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, benzoyl peroxide, tert-butyl benzoyl peroxide, methyl ethyl ketone peroxide, ammonium persulfate or potassium persulfate.

[0024] In the present invention, the main function of the initiator in preparing the coating is that it can decompose into active species to initiate monomer polymerization.

[0025] In the present invention, the initiator content of the monomer mixture is 0.7-3.1% by weight of the monomer mixture. It is undesirable to use an initiator amount exceeding the above range, because too little initiator will result in incomplete polymerization of the antibacterial coating used on the concrete surface, and too much initiator will result in the antibacterial coating used on the concrete surface having a low viscosity and a short molecular chain, which is not conducive to the adhesion and film formation of the resin.

[0026] Preferably, the chain transfer agent is one or more of n-dodecyl mercaptan, tert-dodecyl mercaptan or an aliphatic mercaptan chain transfer agent.

[0027] In the present invention, the main function of the chain transfer agent in the synthesis of the antibacterial coating for concrete surface of the present invention is to cause free radical transfer of chain-growing free radicals and regulate the molecular weight of the polymer.

[0028] In the present invention, the amount of chain transfer agent added is 0.3-2.0% by weight of the monomer mixture. If the amount of chain transfer agent is less than 0.3%, it will make it difficult to terminate the free radical polymerization; if the amount of chain transfer agent is greater than 2.0%, the polymer viscosity will decrease and the molecular chain will be too short. Therefore, the amount of chain transfer agent added is preferably 0.3-2.0%, preferably 0.6-1.6%, and more preferably 0.9-1.4%.

[0029] Preferably, the solvent is one or more selected from toluene, xylene, n-butanol, butyl acetate, ethyl acetate, cyclohexanone or methyl isobutyl ketone.

[0030] In the present invention, the amount of solvent added is 75-125% by weight of the monomer mixture. If the amount of solvent used exceeds the above range, it is not advisable because too much solvent not only brings air pollution but also causes solvent waste.

[0031] A method for preparing an antibacterial coating for a concrete surface comprises the following steps:

[0032] Step 1: Methyl methacrylate, butyl acrylate, sodium acrylate, ethylene urea ethoxy methacrylate, and 8-methyl-N-vanillamide capsaicin derivative are mixed in a three-necked flask at a molar ratio of 12-60:20-60:2-10:2-10:1-5 to obtain a monomer mixture;

[0033] Step 2: adding 0.7-3.1% of an initiator based on the weight of the monomer mixture to the monomer mixture and mixing uniformly to obtain a monomer mixture containing an initiator;

[0034] Step 3: Add 75-125% of the solvent based on the weight of the monomer mixture, add 0.3-2.0% of the chain transfer agent based on the weight of the monomer mixture, and add 10-20% of the monomer mixture containing the initiator based on the weight of the monomer mixture, and stir evenly;

[0035] Step 4: introduce nitrogen into the three-necked flask for 10-30 minutes, and at the same time control the reaction temperature of the reaction mixture at 75-110°C under nitrogen protection, divide the remaining monomer mixture containing the initiator into 1-10 parts, add one part every 10-20 minutes, and react for 2-6 hours under the current conditions to obtain a light yellow transparent viscous acrylic resin, i.e., the antibacterial coating.

[0036] In this step, the temperature of the reaction mixture is controlled at 75-110°C. If the temperature of the reaction mixture is lower than 75°C, it is not conducive to initiating monomer polymerization; if the temperature of the reaction mixture is higher than 110°C, the active species will be ineffective; therefore, a temperature of the reaction mixture of 75-110°C is appropriate, preferably 85-100°C, and more preferably 88-96°C.

[0037] In the present invention, the main purpose of adding the remaining monomer mixture containing the initiator into the reaction in 4-10 portions is to avoid agglomeration caused by excessive single addition or explosion caused by excessive local temperature.

[0038] The three-necked flask used in this step is a three-necked flask equipped with a stirrer and a condenser, which is commonly used in the art.

[0039] In the present invention, the concrete is prepared from 10-20 parts of cement, 20-30 parts of sand, 30-40 parts of gravel and 5-10 parts of water.

[0040] The ultraviolet spectrophotometer used in the present invention is an instrument currently sold on the market for measuring bacterial concentration.

[0041] Preferably, the preparation method of 8-methyl-N-vanillamide capsaicin derivative comprises the following steps:

[0042] Prepare a first mixture of 4-methylbenzoic acid, N-hydroxymethyl acrylamide, sulfuric acid and anhydrous ethanol in a mass ratio of 1-5:1-5:1-5:6-20;

[0043] Stirring the first mixture to react at 30-50° C. for 48-72 hours to obtain a crude 8-methyl-N-vanillamide capsaicin derivative;

[0044] The crude 8-methyl-N-vanillamide capsaicin derivative was recrystallized from anhydrous ethanol several times to obtain the 8-methyl-N-vanillamide capsaicin derivative.

[0045] An application of the above-mentioned antibacterial coating for concrete surface in biofouling prevention of marine concrete infrastructure structures.

[0046] Preferably, the antibacterial coating has antibacterial properties.

[0047] The application provides a bacteriostatic coating for a concrete surface and a preparation method and application thereof, and has the following beneficial effects: the bacteriostatic coating for a concrete surface prepared by the application is simple in preparation operation, and raw materials are easy to obtain, low in cost and environmentally friendly; the application introduces a capsaicin derivative monomer into the bacteriostatic coating for a concrete surface, improves the bacteriostatic property of the resin, and solves the problem of biological fouling of a concrete structure in marine infrastructure construction. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 is a coating bacteriostatic experiment result graph prepared by the application in the embodiment 1;

[0049] Figure 2 is a fluorescent effect comparison graph of the bacteriostatic coating. DETAILED DESCRIPTION

[0050] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by a person skilled in the art without creative work fall within the protection scope of the application.

[0051] In view of the above technical problems, the application provides a bacteriostatic coating for a concrete surface and a preparation method and application thereof, so as to solve the problems in the background art.

[0052] I. Preparation of the bacteriostatic coating

[0053] Embodiment 1: the implementation steps of the embodiment are as follows:

[0054] A. Preparation of a monomer mixture

[0055] Methyl methacrylate, butyl acrylate, sodium acrylate, ethylene urea methacrylate ethoxy ester and 8-methyl-N-vanillyl amide capsaicin derivative are mixed according to a molar ratio of 12:20:2:2:1 to obtain a monomer mixture; then, 2.7% of ammonium persulfate initiator based on the weight of the monomer mixture is added to the monomer mixture, and the mixture is uniformly mixed to obtain a monomer mixture containing an initiator.

[0056] B. Synthesis of the bacteriostatic coating for a concrete surface

[0057] Into a three-necked flask, 85% of methyl isobutyl ketone solvent based on the weight of the monomer mixture, 1.0% of dodecyl mercaptan chain transfer agent based on the total weight of the reactants, and 20% of the monomer mixture containing the initiator obtained in step A based on the weight of the monomer mixture are added, and the mixture is uniformly stirred;

[0058] The nitrogen was introduced into the three-necked flask for 26 minutes, and the reaction temperature of the reaction mixture was controlled at 110°C under the protection of nitrogen. The remaining monomer mixture containing initiator was evenly divided into 6 portions, and one portion was added every 17 minutes. The continuous reaction was carried out for 3 hours under the protection of nitrogen, and a transparent viscous light yellow bacteriostatic coating product for concrete surface was obtained.

[0059] The solid content of the bacteriostatic coating for concrete surface was calculated by using the conventional solid content calculation method, and the solid content was 99.1% by weight.

[0060] Example 2: The implementation steps of this example are as follows:

[0061] A, monomer mixture preparation

[0062] Methyl methacrylate, butyl acrylate, sodium acrylate, ethylene urea methacrylate ethoxy, 8-methyl-N-vanillyl amide capsaicin derivative were mixed according to the molar ratio of 60:45:5:5:2 to obtain a monomer mixture. Then, 2.7% ammonium persulfate initiator by weight of the monomer mixture was added to the monomer mixture, and mixed uniformly to obtain a monomer mixture containing initiator.

[0063] B, synthesis of bacteriostatic coating for concrete surface

[0064] Into the three-necked flask, 85% methyl isobutyl ketone solvent by weight of the monomer mixture, 1.5% tertiary dodecyl mercaptan chain transfer agent by weight of the total reactants, and 20% monomer mixture containing initiator obtained in step A by weight of the monomer mixture were added respectively, and stirred uniformly;

[0065] The nitrogen was introduced into the three-necked flask for 30 minutes, and the reaction temperature of the reaction mixture was controlled at 105°C under the protection of nitrogen. The remaining monomer mixture containing initiator was evenly divided into 8 portions, and one portion was added every 15 minutes. The continuous reaction was carried out for 4 hours under the protection of nitrogen, and a transparent viscous light yellow bacteriostatic coating product for concrete surface was obtained.

[0066] The solid content of the bacteriostatic coating for concrete surface was calculated by using the conventional solid content calculation method, and the solid content was 98.9% by weight.

[0067] Example 3: The implementation steps of this example are as follows:

[0068] A, monomer mixture preparation

[0069] Methyl methacrylate, butyl acrylate, sodium acrylate, ethoxylated ethylene urea methacrylate, 8-methyl-N-vanillyl amide capsaicin derivative were mixed in a molar ratio of 50:20:3:2:2 to obtain a monomer mixture; then, 2.7% ammonium persulfate initiator based on the weight of the monomer mixture was added to the monomer mixture and mixed uniformly to obtain a monomer mixture containing an initiator.

[0070] B. Synthesis of bacteriostatic coating for concrete surface

[0071] Into a three-necked flask, 85% methyl isobutyl ketone solvent based on the weight of the monomer mixture, 1.4% n-dodecyl mercaptan chain transfer agent based on the total weight of the reactants, and 20% monomer mixture containing initiator obtained in step A based on the weight of the monomer mixture were added and stirred uniformly;

[0072] Nitrogen was introduced into the three-necked flask for 15 minutes, and the reaction temperature of the reaction mixture was controlled at 100°C under nitrogen protection. The remaining monomer mixture containing initiator was evenly divided into 6 portions, and one portion was added every 20 minutes. The continuous reaction was carried out under nitrogen protection for 4 hours to obtain a transparent viscous light yellow bacteriostatic coating product for concrete surface;

[0073] The solid content of the bacteriostatic coating for concrete surface was calculated to be 99.3% by weight by using the conventional solid content calculation method.

[0074] Example 4: The implementation steps of this example are as follows:

[0075] A. Preparation of monomer mixture

[0076] Methyl methacrylate, butyl acrylate, sodium acrylate, ethoxylated ethylene urea methacrylate, 8-methyl-N-vanillyl amide capsaicin derivative were mixed in a molar ratio of 15:60:10:10:5 to obtain a monomer mixture; then, 2.7% ammonium persulfate initiator based on the weight of the monomer mixture was added to the monomer mixture and mixed uniformly to obtain a monomer mixture containing an initiator.

[0077] B. Synthesis of bacteriostatic coating for concrete surface

[0078] To a three-necked flask, 85% of methyl isobutyl ketone solvent and 1.0% of n-dodecyl mercaptan chain transfer agent were added based on the total weight of the reactants. The monomer mixture containing the initiator obtained in step A was added at 20% based on the weight of the monomer mixture, and the mixture was stirred uniformly. Nitrogen was introduced into the three-necked flask for 25 minutes. The reaction temperature of the reaction mixture was controlled at 100° C. under nitrogen protection. The remaining monomer mixture containing the initiator was divided into 8 equal portions, and one portion was added every 20 minutes. The reaction was continued under nitrogen protection for 3.5 hours to obtain a transparent, viscous, light yellow antibacterial coating product for concrete surface.

[0079] According to conventional solid content calculation method, the solid content of the antibacterial coating for concrete surface is 98.9% by weight.

[0080] 2. Performance test of antibacterial coating applied on concrete surface

[0081] The implementation of this application example is as follows:

[0082] The E. coli strain sold by Beijing Prudin Biotechnology Co., Ltd. under the trade name E. coli was used for antibacterial testing. The concentration of bacteria was tested using an ultraviolet spectrophotometer sold by Shanghai Precision Scientific Instrument Co., Ltd. The test results are listed in the attached Figure 1 middle.

[0083] Attachment Figure 1 Bacterial inhibition tests were conducted on coatings using the antibacterial coating for concrete surfaces prepared in Example 1 as a functional additive. Antibacterial inhibition tests were also conducted on test blocks without the antibacterial coating for concrete surfaces, serving as a blank control group. Compared to the control group, the coating prepared using the antibacterial coating for concrete surfaces of the present invention as an additive exhibited superior antibacterial properties.

[0084] The fluorescence effect of the coating was tested using an ultraviolet spectrometer sold by Shandong Lanjing Electronic Technology Co., Ltd. under the trade name UV spectrometer. The test results are listed in the attached Figure 2 Attached Figure 2 The following is a spectrum test of a coating prepared using the antibacterial coating for concrete surfaces prepared in Example 1. A UV test was also conducted using a blank control group of test pieces without the antibacterial coating for concrete surfaces. Compared to the control group, the coating prepared using the antibacterial coating for concrete surfaces of the present invention exhibited a superior fluorescence effect.

[0085] The explanation is that the direct reason for the fluorescent color development is that there is a conjugated π electron system in the molecular structure of 8-methyl-N-vanillamide capsaicin derivatives. When irradiated by ultraviolet light, the conjugated π electron system will jump from the ground state to the excited state; when the electron falls back from the excited state to the ground state, it will release energy in the form of fluorescence, thereby generating a visible fluorescence signal.

[0086] Figure 2 The fluorescence effect demonstrates the successful presence and uniform distribution of the capsaicin derivative in the coating, verifying the effectiveness of the coating preparation process and the stability of the antibacterial components. Furthermore, the photophobic nature of some microorganisms prevents their attachment, further enhancing the antibacterial effect. Combined with the antibacterial performance test results, this demonstrates the feasibility of the invention.

[0087] It is explained that in the later construction process, the distribution of fluorescence intensity can intuitively reflect the coating uniformity on the concrete surface, which is convenient for construction quality control; the attenuation degree of the fluorescence spectrum can indirectly judge the loss or degradation of the antibacterial components in the coating, and long-term effectiveness evaluation can be carried out.

[0088] The embodiments described above are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. An antibacterial coating for concrete surface, characterized in that: The raw materials of the antibacterial coating, calculated by weight, include: 100 parts of monomer mixture, 0.7-3.1 parts of initiator, 0.3-2.0 parts of chain transfer agent, and 75-125 parts of solvent; The monomer mixture comprises methacrylate monomer, acrylate monomer, sodium acrylate, methacrylate urea monomer and capsaicin derivative in a molar ratio of 12-60:20-60:2-10:2-10:1-5.

2. The antibacterial coating for concrete surface according to claim 1, characterized in that: The methacrylate monomer is selected from one or more of methyl methacrylate, ethyl methacrylate, hydroxyethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate or octadecyl methacrylate.

3. The antibacterial coating for concrete surface according to claim 1, characterized in that: The acrylate monomer is selected from one or more of methyl acrylate, ethyl acrylate, hydroxyethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate or octadecyl acrylate.

4. The antibacterial coating for concrete surface according to claim 1, characterized in that: The urea methacrylate monomer is selected from one or more of ethoxylated ethylene urea methacrylate, ethylene urea ethoxylate methacrylate, and ethylene urea methacrylate.

5. The antibacterial coating for concrete surface according to claim 1, characterized in that: The capsaicin derivative is selected from one or more of a benzene ring, a phenolic hydroxyl group and an amide group.

6. The antibacterial coating for concrete surface according to claim 1, characterized in that: The methacrylate monomer is methyl methacrylate; the acrylate monomer is butyl acrylate; the methacrylate urea monomer is ethylene urea ethoxy methacrylate; and the capsaicin derivative is an 8-methyl-N-vanillamide capsaicin derivative, and its structural formula is shown below:

7. A method for preparing an antibacterial coating for a concrete surface, characterized in that: The following steps are involved: Step 1: Methyl methacrylate, butyl acrylate, sodium acrylate, ethylene urea ethoxy methacrylate, and 8-methyl-N-vanillamide capsaicin derivative are mixed in a three-necked flask at a molar ratio of 12-60:20-60:2-10:2-10:1-5 to obtain a monomer mixture; Step 2: adding 0.7-3.1% of an initiator based on the weight of the monomer mixture to the monomer mixture and mixing uniformly to obtain a monomer mixture containing an initiator; Step 3: Add 75-125% of the solvent based on the weight of the monomer mixture, add 0.3-2.0% of the chain transfer agent based on the weight of the monomer mixture, and add 10-20% of the monomer mixture containing the initiator based on the weight of the monomer mixture, and stir evenly; Step 4: introduce nitrogen into the three-necked flask for 10-30 minutes, and at the same time control the reaction temperature of the reaction mixture at 75-110°C under nitrogen protection, divide the remaining monomer mixture containing the initiator into 1-10 parts, add one part every 10-20 minutes, and react for 2-6 hours under the current conditions to obtain a light yellow transparent viscous acrylic resin, i.e., the antibacterial coating.

8. The method for preparing an antibacterial coating for a concrete surface according to claim 7, wherein: The preparation method of 8-methyl-N-vanillamide capsaicin derivatives comprises the following steps: Prepare a first mixture of 4-methylbenzoic acid, N-hydroxymethyl acrylamide, sulfuric acid and anhydrous ethanol in a mass ratio of 1-5:1-5:1-5:6-20; Stirring the first mixture to react at 30-50° C. for 24-72 hours to obtain a crude 8-methyl-N-vanillamide capsaicin derivative; The crude 8-methyl-N-vanillamide capsaicin derivative was recrystallized from anhydrous ethanol several times to obtain the 8-methyl-N-vanillamide capsaicin derivative.

9. Use of the antibacterial coating for concrete surface according to claim 1 in biofouling prevention of marine concrete infrastructure structures.

10. The use of the antibacterial coating for concrete surface according to claim 9 in the biofouling prevention of marine concrete infrastructure structures, characterized in that: The antibacterial coating has antibacterial properties.

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