Modified nano silicon dioxide reinforced fluorocarbon resin antibacterial coating as well as preparation method and application thereof

Abstract

The invention relates to the technical field of functional antibacterial coatings, in particular to a modified nano silicon dioxide reinforced fluorocarbon resin antibacterial coating as well as a preparation method and application thereof. The coating has efficient antibacterial performance on standard strains and drug-resistant strains (such as aspergillus niger). According to the material, copper pyrithione and vinyl fluoride-vinyl ether resin form a fusion system, modified nano silicon dioxide inorganic particles are further introduced, the composite antibacterial coating is formed, the water resistance of a coating is remarkably improved, and meanwhile the excellent antibacterial performance is kept. The coating is particularly suitable for long-term protection of wood surfaces in (ancient) buildings and gardens, and an efficient and low-concentration novel solution is provided for solving the problems that a traditional coating is poor in antibacterial property, insufficient in drug-resistant bacterium resistance and the like. The composite antibacterial coating also provides more efficient and stable protection for wood exposed in the environment for a long time, has a wide application prospect, and can be used in multiple fields of building, garden, cultural heritage protection and the like.

Description

Technical Field

[0001] This invention relates to the field of functional antibacterial coatings, and in particular to a modified nano-silica reinforced fluorocarbon resin antibacterial coating, its preparation method, and its application. Background Technology

[0002] The growth of mold and other microorganisms is one of the main causes of wood cracking and decay. Especially in cultural heritage buildings and ancient garden buildings, wooden components are exposed to the external environment for a long time and are affected by factors such as rain, humidity and temperature changes, which leads to increased microbial damage. As the main building material in heritage ancient buildings, wood faces severe protection challenges due to its natural characteristics, strong hygroscopicity and sensitivity to environmental changes (Cheng Xiao et al. Research progress and development trend of building materials with antibacterial and anti-mildew functions [J]. China Building Materials Science and Technology, 2025, 34(06):17-21.DOI:10.26936 / j.cnki.1003-8965. 2025.06.003.).

[0003] Existing technologies commonly employ wood protective coatings containing organic or inorganic antibacterial, antifungal, and antialgae agents for surface treatment of wooden components (Patent CN120005457A). Common organic antibacterial and antifungal agents include quaternary ammonium salts, isothiazolinones, and triazoles, while inorganic antibacterial agents are mostly silver-, copper-, or zinc-loaded glass, ceramics, or oxide materials. Copper pyrithione (CAS No. 14915-37-8) possesses good broad-spectrum antibacterial and antifungal properties due to its dual role as both a metal ion and an organic ligand, and has been used in marine antifouling and industrial coatings (Patents CN120988547A, CN121136282A, etc.). However, in traditional wood coating systems, antibacterial agents are often added through physical mixing, which can easily lead to problems such as uneven dispersion, insufficient compatibility with film-forming substances, and loss due to migration with moisture or organic components during use. This results in a short duration of antibacterial effect, making it difficult to meet the long-term stable protection requirements of heritage wood structures (Patent CN220460433U).

[0004] Patent CN121271379A reports that fluoroethylene vinyl ether (FEVE) resin has excellent weather resistance, UV aging resistance, and gloss and color retention properties. Therefore, this material has been gradually introduced into the field of building exterior walls and high-durability coatings, and is regarded as a potential film-forming material for the surface protection of cultural heritage buildings and ancient wooden components in gardens. However, when organic or metal ion antibacterial agents are directly added to the FEVE resin system, problems such as limited compatibility between the antibacterial agent and the resin matrix, adverse effects of the antibacterial agent on the transparency or color of the coating film, and attenuation of antibacterial performance under long-term outdoor exposure conditions are often encountered (Zhu Yajun. Research and performance study of hydrophobic and easy-to-clean fluorocarbon topcoat [J]. Coatings and Protection, 2021, 42(06):20-24.). Especially for heritage-type wooden components, it is necessary to balance the antibacterial and antifungal effects of the coating with minimizing interference with the original material's appearance and texture ("Technical Standard for Maintenance and Reinforcement of Ancient Wooden Structures" GB / T 50165-2020). This makes the selection of antibacterial agents, fixing methods, and distribution control in the coating more complex, and currently no publicly available effective technology has been found. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the problems of poor interfacial compatibility, reduced water resistance, poor weather resistance and mildew resistance of existing wood protective coatings, thereby providing a composite antibacterial coating.

[0006] The aforementioned material exhibits highly effective antibacterial properties against standard strains, including Aspergillus niger, making it a novel antibacterial material that combines high efficiency, broad spectrum, and low concentration. While ensuring excellent antibacterial performance, this coating significantly improves the weather resistance and waterproofing properties of the coating, making it particularly suitable for the long-term protection of wood and stone surfaces in buildings, ancient buildings, and gardens, providing a highly competitive solution.

[0007] To address the aforementioned technical problems, this invention provides a method for preparing a modified nano-silica reinforced fluorocarbon resin antibacterial coating, comprising the following steps: S11: Add nano-silica, pH adjuster and silane coupling agent to an alcohol aqueous solution and react at 110-130℃ for 10-14 h to obtain the solid product SiO2-silane. S12: Add copper pyridinethione and the solid product SiO2-silane to water containing aqueous fluorocarbon resin, and mix to obtain the modified nano-silica reinforced fluorocarbon resin antibacterial coating.

[0008] The schematic diagram of the synthesis process of the modified nano-silica reinforced fluorocarbon resin antibacterial coating is shown below. Figure 18 As shown.

[0009] Preferably, in step S11, the mass ratio of nano-silica, pH adjuster, and silane coupling agent is 10:1 to 2:20. The silane coupling agent forms a chemically bonded organic molecular layer on the surface of the nano-silica. This lays the foundation for its successful subsequent composite with the water-soluble fluorocarbon resin matrix and its reinforcing and promoting effects.

[0010] Preferably, the alcohol is selected from ethanol.

[0011] Preferably, the pH adjuster is triethylamine. As a pH adjuster for coatings, triethylamine's main advantages are its moderate alkalinity, efficient neutralization, complete volatility, and broad compatibility, making it particularly suitable for water-based coatings requiring high performance and low residue.

[0012] Preferably, the silane coupling agent is selected from γ-aminopropyltriethoxysilane, i.e., KH550.

[0013] Preferably, the particle size of the nano-silica is 12-18 nm.

[0014] Preferably, the concentration of the solute in the alcohol-water solution during the reaction is 60-80 g / L.

[0015] Furthermore, in the alcohol-water solution, the volume fraction of alcohol is 70-80%.

[0016] Preferably, in step S11, after the reaction, the mixture is cooled to room temperature (25±5℃) to remove impurities; the method for removing impurities is as follows: after filtration, the mixture is washed with ethanol 2-4 times and dried under vacuum at 110-130℃ for 8-16 h.

[0017] Preferably, the waterborne fluorocarbon resin emulsion is a waterborne fluoroethylene-vinyl ether (FEVE) resin emulsion with a solid content of 45-50 wt%; this waterborne fluorocarbon resin emulsion was purchased from Ron, with part number RH-00949 and model number R139360-100. The waterborne FEVE resin emulsion achieves top-level performance approaching or reaching the level of traditional solvent-based fluorocarbon coatings in an environmentally friendly waterborne system, making it one of the key technologies for resolving the contradiction between long-term protection and environmental protection requirements.

[0018] Furthermore, the mass ratio of the copper pyridine thione, the solid product SiO2-silane, and the aqueous fluorocarbon resin emulsion is 1:1:3-3.5. This synergistic ratio of the three components constructs a multifunctional composite protective system that is highly effective in preventing bacteria and mold, deeply protects the wood structure, and possesses hydrophobicity and weather resistance.

[0019] Furthermore, in the water containing the aqueous fluorocarbon resin, the volume ratio of the aqueous fluorocarbon resin emulsion to water is 2-4:97. The ultra-low surface energy of the fluorocarbon resin allows it to form a hydrophobic film on the substrate surface and the inner walls of pores, effectively preventing liquid water penetration while allowing water vapor to pass through, thus reducing the risk of foaming.

[0020] Preferably, in step S12, the mixing speed is 600-800 rpm, and the time is 2-4 h. Modified silica, as solid nanoparticles, has a strong tendency to agglomerate. Appropriate stirring will provide sufficient shear force to break these soft agglomerates, allowing them to be uniformly dispersed in the resin emulsion as native or smaller aggregates. This is a prerequisite for exerting its reinforcing and hardening effects. If the speed is too low, uneven particle dispersion may occur, potentially leading to localized brittleness or particle formation in the paint film.

[0021] Specifically, the preparation method of the modified nano-silica reinforced fluorocarbon resin antibacterial coating includes the following steps: Step 1: Add nano-silica to ethanol and stir with a magnetic stirrer at 400 rpm for 30 minutes to obtain a uniform dispersion. Step 2: Add triethylamine to the dispersion and adjust the pH to neutral; Step 3: Add KH550 to the dispersion and shake well, then reflux at 120°C for 12 h; Step 4: After the reaction is complete, the solution is cooled to room temperature (25±5℃). The solid product is separated by filtration and washed multiple times with anhydrous ethanol by centrifugation to remove impurities. The obtained solid is dried overnight under vacuum at 120℃. The product is named SiO2-KH550. Step 5: Add 3 mL of FEVE emulsion to 97 mL of deionized water to prepare a 3% (v / v) FEVE solution. Add the same mass of SiO2-KH550 and copper pyridinethione. Stir with a magnetic stirrer at 600-800 rpm for 3 h to obtain a modified nano-silica reinforced fluorocarbon resin antibacterial composite coating, named CupT-FEVE-SiO2.

[0022] The KH550 has the structural formula shown in Formula I:

[0023] Formula I; The structural formula and polymerization process of SiO2-KH550 are shown in Formula II:

[0024] Formula II; The present invention also provides a modified nano-silica reinforced fluorocarbon resin antibacterial coating prepared by the above preparation method.

[0025] Preferably, when the fungus is used as the standard strain, the amount of SiO2-silane and copper pyridinethione (mass ratio of 1:1) added is 0.05-0.15 g, and the concentration of the resulting solution is 0.6-3 g / L.

[0026] This invention also provides the application of the above-mentioned modified nano-silica reinforced fluorocarbon resin antibacterial coating in wood protection. The anti-mildew coating does not affect the appearance and texture of the wood during use and can protect the wood from microbial attack for a long time. The coating is used for mildew protection of substrates such as wood and stone, and is particularly suitable for the surface protection of wooden components in cultural heritage buildings and ancient garden structures.

[0027] Preferably, the method of wood protection includes applying the modified nano-silica reinforced fluorocarbon resin antibacterial coating to the surface of the wood to inhibit the growth of Aspergillus niger (strain number CMCC98003).

[0028] Furthermore, the modified nano-silica reinforced fluorocarbon resin antibacterial coating is used at a concentration range of 0.2 g / L to 3 g / L.

[0029] Furthermore, when the concentration of the coating is 0.6 g / L, it has an inhibitory effect on the growth of mold on the wood surface, and at a concentration of 1*10 g / L... 5 The standard Aspergillus niger strain with a concentration of CFU / mL achieved an inhibition rate (or antifungal rate) of over 50%.

[0030] Furthermore, when the concentration of the coating is 2 g / L, it exhibits highly effective anti-mildew properties on wood surfaces, and for concentrations of 1*10 g / L... 5 The standard Aspergillus niger strain with a concentration of CFU / mL achieved an inhibition rate (or antifungal rate) of over 99.99%.

[0031] Furthermore, the coating can exert its antibacterial effect under both light and non-light conditions.

[0032] Compared with the prior art, the above-described technical solution of the present invention has the following advantages: (1) The material preparation method of the present invention is simple, convenient to operate, mild reaction conditions, and does not require complex and expensive equipment, which is conducive to large-scale production and practical application.

[0033] (2) The material of the present invention breaks through the limitation that ordinary varnish and FEVE have no anti-mildew effect, while retaining the hydrophobicity and weather resistance of nano silica.

[0034] (3) The material of the present invention exhibits significant antibacterial effects even at extremely low concentrations, and has a low minimum antibacterial concentration (MIC). Specifically, CuPT-FEVE-SiO2 is effective against high concentrations of Aspergillus niger (1×10⁻⁶). 5 A concentration of only 0.6 g / L (CFU / mL) is sufficient to kill Aspergillus niger strains, and only 2 g / L is required for complete eradication. This concentration is significantly lower than that of similar materials mentioned in the background section, resulting in far greater efficiency than existing technologies and a substantial reduction in material usage costs and potential biotoxicity. Attached Figure Description

[0035] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0036] Figure 1 The 3% (v / v) FEVE aqueous solution and 3 g / L CuPT-FEVE-SiO2 coating used in Example 2 were compared with 1×10 5 Comparison of antifungal properties of CFU / mL resistant Aspergillus niger; both culture media included wood blocks coated with 3% FEVE (control) and wood blocks coated with 3 g / L CupT-FEVE-SiO2 (experiment); among them, (a) and (b) are the experimental results of parallel experimental groups; Figure 2 The 3% (v / v) FEVE aqueous solution and 2 g / L CuPT-FEVE-SiO2 coating used in Example 2 were compared with 1×10 5 Comparison of antifungal properties of CFU / mL resistant Aspergillus niger; both culture media included wood blocks coated with 3% FEVE (control) and wood blocks coated with 2 g / L CupT-FEVE-SiO2 (experiment); among them, (c) and (d) are the experimental results of parallel experimental groups; Figure 3 The 3% (v / v) FEVE aqueous solution and 1 g / L CuPT-FEVE-SiO2 coating used in Example 2 were compared with 1×10 5 Comparison of antifungal properties of CFU / mL resistant Aspergillus niger; both culture media included wood blocks coated with 3% FEVE (control) and wood blocks coated with 1 g / L CupT-FEVE-SiO2 (experiment); among them, (e) and (f) are the experimental results of parallel experimental groups; Figure 4 The 3% (v / v) FEVE aqueous solution and 0.6 g / L CuPT-FEVE-SiO2 in Example 2 were used to prepare 1×10⁻⁶ ppm of the solution. 5Comparison of antifungal properties of CFU / mL resistant Aspergillus niger; both culture media included wood blocks coated with 3% FEVE (control), and the right side included wood blocks coated with 0.6 g / L CupT-FEVE-SiO2 (experiment); where (g) and (h) are the experimental results of parallel experimental groups; Figure 5 The 3% (v / v) FEVE aqueous solution and 0.2 g / L CuPT-FEVE-SiO2 in Example 2 were used to prepare 1×10⁻⁶ ppm of FEVE-SiO₂. 5 Comparison of antifungal properties of CFU / mL resistant Aspergillus niger; both culture media included wood blocks coated with 3% FEVE (control) and wood blocks coated with 0.2 g / L CupT-FEVE-SiO2 (experiment); where (i) and (j) are the experimental results of parallel experimental groups; Figure 6 The 3% (v / v) FEVE aqueous solution and 3% (v / v) varnish in Example 3 were compared with 1×10 5 Comparison of antibacterial properties of CFU / mL resistant Aspergillus niger, where (a) and (c) are wood block samples coated with 3% FEVE by volume, and (b) and (d) are wood block samples coated with 3% varnish by volume. Figure 7 In Example 3, 3% varnish and CuPT-FEVE-SiO2 were used to treat 1×10⁻⁶ varnish and 1×10⁻⁶ varnish. 5 Comparison of antibacterial properties of CFU / mL resistant Aspergillus niger, where (a) and (c) are wood block samples coated with varnish, and (b) and (d) are wood block samples coated with CupT-FEVE-SiO2; Figure 8 The 3% FEVE aqueous solution, 2 g / L CuPT-FEVE-SiO2, and 3 g / L CuPT-FEVE in Example 4 were used to treat 1×10⁻⁶ FEVE. 5 Schematic diagram of the inhibition zone of CFU / mL drug-resistant Aspergillus niger; where (a) and (b) are the experimental results of parallel experimental groups; Figure 9 For example, sample pair 1×10 in Example 4 5 Actual photographs of the inhibition zone test results of CFU / mL drug-resistant Aspergillus niger; the samples included 3% FEVE aqueous solution, 0.2 g / L CupT-FEVE-SiO2, 0.6 g / L CupT-FEVE-SiO2, 1 g / L CupT-FEVE-SiO2, 2 g / L CupT-FEVE-SiO2 and 3 g / L CupT-FEVE-SiO2; Figure 10The 3% FEVE aqueous solution, 3% varnish, 2 g / L CuPT-varnish, and 2 g / L CuPT-FEVE-SiO2 in Example 4 were used to treat 1×10⁻⁶ FEVE-SiO₂. 5 A schematic diagram of the inhibition zone of CFU / mL drug-resistant Aspergillus niger, where (a) and (b) are the experimental results of parallel experimental groups; Figure 11 The images are scanning electron microscope (SEM) images of (a) FEVE and (b) CuPT-FEVE-SiO2 in Example 1. Figure 12 This is an energy dispersive spectroscopy (EDS) single-element surface distribution diagram of CuPT-FEVE-SiO2 in Example 1; Figure 13 These are comparison images of the fine structure characterization of copper K-edge X-ray absorption of the CuPT-FEVE-SiO2 composite material prepared in Example 1 of this invention and a standard metallic copper sample; where (a) is the normalized X-ray absorption near-edge structure spectrum; and (b) is the radial distribution function obtained by Fourier transform of the extended X-ray absorption fine structure oscillation signal. Figure 14 The X-ray diffraction pattern (XRD) of CuPT-FEVE-SiO2 in Example 1 is shown. Figure 15 The image shows the synchrotron radiation wide-angle X-ray scattering characterization of CuPT-FEVE-SiO2 in Example 1; where (a) is a two-dimensional wide-angle X-ray scattering spectrum, and (b) is a one-dimensional intensity integral curve obtained by integrating the two-dimensional spectrum with the azimuth angle. Figure 16 The image shows the static water contact angle test results of CuPT-FEVE-SiO2 in Example 1; where (a) and (b) are contact angle measurement images of different test areas on the surface of the composite coating, respectively. The test liquid is deionized water and the test temperature is 21.7℃. Figure 17 EDS layered image of CuPT-FEVE-SiO2 in Example 1; Figure 18 This is a schematic diagram of the synthesis process of CupT-FEVE-SiO2; Figure 19 The 3% (v / v) FEVE aqueous solution, 2 g / L CuPT-FEVE-SiO2, and 2 g / L FEVE-SiO2 in Example 5 were used to treat 1×10⁻⁶ FEVE-SiO2. 5 Comparison of antibacterial properties of CFU / mL resistant Aspergillus niger; where (a) and (c) are wood block samples coated with 3% FEVE by volume, (b) is a wood block sample coated with 2 g / L CupT-FEVE-SiO2, and (d) is a wood block sample coated with 2 g / L FEVE-SiO2. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0038] Unless otherwise specified, the technical means used in the following embodiments are all conventional means well known to those skilled in the art, and the experimental methods without specific conditions are all conventional methods in the art. Unless otherwise specified, the materials and reagents used in the following embodiments are all commercially available.

[0039] The standard strain of Aspergillus niger used in the following examples was CMCC98003, purchased from Kaibei Technology (Suzhou) Co., Ltd. The wood samples used were from Fuchuan Caiyuan Wood Processing Plant in Hezhou, Guangxi Zhuang Autonomous Region; none of the wood samples underwent waterproofing or antibacterial treatment before the experiment.

[0040] Example 1: Preparation of CuPT-FEVE-SiO2 This embodiment relates to a method for preparing a copper pyridine thione-fluoroethylene-vinyl ether resin-modified nano silica composite antibacterial coating CuPT-FEVE-SiO2, the synthesis reaction formula is as follows: Figure 18 As shown, taking a 2 g / L CupT-FEVE-SiO2 solution as an example, the specific steps are as follows: (1) 1 g of 15 nm nano-silica was added to 50 mL of ethanol aqueous solution (ethanol volume fraction 75%) and stirred for 30 min at 400 rpm using a magnetic stirrer to obtain a uniform dispersion. 200 μL (0.1456 g) of triethylamine was added to the dispersion and the pH was adjusted to neutral. 2 g of silane coupling agent KH550 was added to the dispersion and shaken well. The mixture was then refluxed at 120 °C for 12 h. After the reaction was completed, the solution was cooled to room temperature and the solid product was separated by filtration. The solid product was washed three times by centrifugation with anhydrous ethanol to remove impurities. The obtained solid was dried overnight under vacuum at 120 °C to obtain the product SiO2-KH550.

[0041] (2) Add 3 mL (total 3.25 g, solid content 48%) of waterborne fluoroethylene-vinyl ether (FEVE) resin emulsion to 97 mL of deionized water to prepare a 3% FEVE solution. Then add 0.1 g of SiO2-KH550 and 0.1 g of copper pyridinethione, respectively. Stir with a magnetic stirrer at 600 rpm for 3 h to obtain a light green solution, named CupT-FEVE-SiO2.

[0042] Figure 11The scanning electron microscope (SEM) images show the surface microstructure of the above-mentioned material, in which... Figure 11 The surface of the pure FEVE resin in (a) is relatively smooth and flat, while Figure 11 The surface of the CuPT-FEVE-SiO2 composite coating shown in (b) exhibits a distinct micro-nano rough structure, which is due to the filling and accumulation of modified nano-silica and copper pyridine thiophene in the resin matrix. Figure 12 The EDS energy dispersive spectroscopy layered image further revealed the elemental distribution of the material. The image clearly shows that elements such as F (from FEVE), Si (from modified SiO2), Cu and S (from copper pyridinethione) are uniformly distributed on the coating surface, proving that the components have been successfully composited and well dispersed.

[0043] also, Figure 14 The X-ray diffraction (XRD) pattern showed that the CuPT-FEVE-SiO2 composite material retained the characteristic diffraction peaks of copper pyridinethione (CuPT), indicating that the antibacterial agent did not decompose during the composite process and maintained its crystal structure; meanwhile, the broad peak appearing at around 20° corresponds to the amorphous silicon dioxide and polymer substrate. Figure 13 X-ray absorption fine structure spectroscopy (XAFS) further confirmed that the coordination environment of divalent copper ions remained stable before and after recombination. Based on the above characterization results, it is demonstrated that copper pyrithione and modified nano-silica have been successfully introduced into the FEVE resin system, and a CuPT-FEVE-SiO2 composite antibacterial coating has been successfully prepared.

[0044] Example 2: Antibacterial experiment of FEVE and CupT-FEVE-SiO2 on standard strains 1. Experimental Procedure (1) Take 50 μL of 3% FEVE aqueous solution and 50 μL of CuPT-FEVE-SiO2 aqueous solution with solute concentrations of 0.2 g / L, 0.6 g / L, 1 g / L, 2 g / L and 3 g / L respectively, and drop them onto the surface of untreated fir blocks (the blocks are 2 cm long, 2 cm wide and 0.5 cm high). Spread them evenly and air dry them for 12 hours. The blocks coated with 3% FEVE are recorded as the control group and the blocks coated with CuPT-FEVE-SiO2 are recorded as the experimental group.

[0045] (2) Take 0.1 mL of standard Aspergillus niger solution (strain number CMCC98003, purchased from Kaibei Technology (Suzhou) Co., Ltd.), and obtain a bacterial concentration of 1×10⁻⁶. 9 A certain amount of bacterial culture was taken from the concentration of CFU / mL and mixed with sterile phosphate buffered solution (PBS) to reduce the bacterial concentration to 1×10⁻⁶. 5CFU / mL.

[0046] (3) Select a Sabouraud dextrose agar (SDA) medium with a diameter of 90 mm and a height of 15 mm, and use a sterile blade to cut two grooves with a length and width of 2 cm and a thickness of 0.5 cm on the surface of the agar.

[0047] (4) Place the previously coated FEVE wood block (control group) in the empty slot on the left and coat the wood block with 30 μL of FEVE with a volume fraction of 3%; place the previously coated CupT-FEVE-SiO2 wood block (experimental group) in the empty slot on the right and coat the wood block with 30 μL of CupT-FEVE-SiO2, and let it air dry naturally.

[0048] (5) Add 30 μL of 1×10⁻⁶ solution to the surface of the air-dried wood block. 5 CFU / mL standard Aspergillus niger was evenly coated onto the surface and sides of the wood block. Each concentration was tested in triplicate to eliminate errors. After coating, the blocks were placed in a 28°C incubator under ambient air and co-cultured with the Aspergillus niger and the wood block for 48 hours.

[0049] (6) Take out the petri dish and take a picture of the growth of the mold.

[0050] 2. Experimental Results FEVE aqueous solution and CuPT-FEVE-SiO2 aqueous solutions of different concentrations for 1×10 5 The antibacterial properties of CFU / mL standard Aspergillus niger are as follows: Figures 1 to 5 As shown, FEVE coating alone does not have antibacterial properties, but when the concentration of CupT-FEVE-SiO2 is greater than 0.6 g / L, it will show a significant antibacterial effect.

[0051] Example 3: Comparative experiment on the antifungal properties of varnish and CupT-FEVE-SiO2 against standard bacterial strains 1. Experimental Procedure (1) Dissolve 3 mL of commercial varnish (UGCOO high-hardness water-based wood varnish) in 97 mL of deionized water to prepare a varnish aqueous solution with a volume fraction of 3%. Take 50 μL of the varnish aqueous solution and 2 g / L of the CuPT-FEVE-SiO2 aqueous solution prepared in Example 1, and drop them onto the surface of untreated fir blocks (the blocks are 2 cm long, 2 cm wide, and 0.5 cm high). Spread the solution evenly and air dry for 12 hours. The blocks coated with the 3% varnish aqueous solution are recorded as the control group, and the blocks coated with CuPT-FEVE-SiO2 are recorded as the experimental group.

[0052] (2) Take 0.1 mL of standard Aspergillus niger solution (strain number CMCC98003, purchased from Kaibei Technology (Suzhou) Co., Ltd.), and obtain a bacterial concentration of 1×10⁻⁶. 9 CFU / mL, a certain amount of bacterial culture was taken from it and mixed with sterile PBS solution to reduce the bacterial concentration to 1×10⁻⁶. 5 CFU / mL.

[0053] (3) Select an SDA medium with a diameter of 90 mm and a height of 15 mm, and use a sterile blade to cut two grooves with a length and width of 2 cm and a thickness of 0.5 cm on the surface of the agar.

[0054] (4) Place the previously coated wood block (control group) in the empty slot on the left and coat the wood block with 30 μL of 3% varnish; place the previously coated wood block (experimental group) coated with CuPT-FEVE-SiO2 aqueous solution in the empty slot on the right and coat the wood block with 30 μL of CuPT-FEVE-SiO2 aqueous solution, and let it air dry naturally.

[0055] (5) Add 30 μL of 1×10⁻⁶ solution to the surface of the air-dried wood block. 5 CFU / mL standard Aspergillus niger was evenly coated onto the surface and sides of the wood block. Each concentration was tested in triplicate to eliminate errors. After coating, the blocks were placed in a 28°C incubator under ambient air and co-cultured with the Aspergillus niger and the wood block for 48 hours.

[0056] (6) Take out the petri dish and take a picture of the growth of the mold.

[0057] 2. Experimental Results (1) Varnish and CupT-FEVE-SiO2 against 1×10 5 The antibacterial properties of CFU / mL standard Aspergillus niger are as follows: Figure 7 As shown in the figure, the plain varnish coating does not have antibacterial properties, while CupT-FEVE-SiO2 exhibits a significant antibacterial effect.

[0058] Example 4: Antibacterial zone experiment 1. Experimental Procedure (1) Dissolve 3 mL of commercial varnish (UGCOO high hardness water-based wood varnish) in 97 mL of deionized water to prepare a varnish solution with a volume fraction of 3%. Dissolve 0.2 g of copper pyridinethione in 100 mL of varnish solution to obtain a dark green aqueous solution with a weight-volume ratio of 2 g / L, which is denoted as 2 g / L CupT-varnish.

[0059] (2) Take 60 μL of a concentration of 1×10 5CFU / mL of standard Aspergillus niger was dropped onto the surface of SDA agar, and the bacterial suspension was spread evenly with a spreader. Using a sterile mold, circular grooves with a diameter of 0.5 cm were cut into the agar surface. 10 μL each of the following solutions were added to the circular grooves on the agar surface: 3% FEVE aqueous solution, 3% varnish, 0.2 g / L CupT-FEVE-SiO2 aqueous solution from Example 1, 0.6 g / L CupT-FEVE-SiO2 aqueous solution, 1 g / L CupT-FEVE-SiO2 aqueous solution, 2 g / L CupT-FEVE-SiO2 aqueous solution, and 3 g / L CupT-FEVE-SiO2 aqueous solution. The agar was then placed in a 28°C incubator under air atmosphere and incubated for 48 h.

[0060] 2. Experimental Results (1) 3% FEVE aqueous solution, 2 g / L CupT-FEVE-SiO2 aqueous solution, and 3 g / L CupT-FEVE-SiO2 aqueous solution against 1×10 5 The antibacterial properties of CFU / mL standard Aspergillus niger are as follows: Figure 8 As shown in the figure, the FEVE coating alone does not have antibacterial properties. Both 2 g / L CupT-FEVE-SiO2 aqueous solution and 3 g / L CupT-FEVE-SiO2 aqueous solution have significant anti-mildew effects, with the 3 g / L CupT-FEVE-SiO2 aqueous solution showing the best anti-mildew effect.

[0061] (2) 3% FEVE, 0.2 g / L CupT-FEVE-SiO2 aqueous solution, 0.6 g / L CupT-FEVE-SiO2 aqueous solution, 1 g / L CupT-FEVE-SiO2 aqueous solution, 2 g / L CupT-FEVE-SiO2 aqueous solution, and 3 g / L CupT-FEVE-SiO2 aqueous solution against 1×10 5 The antibacterial properties of CFU / mL standard Aspergillus niger are as follows: Figure 9 As shown in the figure, the FEVE coating alone does not have antibacterial properties. When the concentration of CupT-FEVE-SiO2 aqueous solution is greater than 1 g / L, it has a significant anti-mildew effect, and the 3 g / L CupT-FEVE-SiO2 aqueous solution has the best anti-mildew effect.

[0062] (3) 3% FEVE, 3% varnish, 2 g / L CupT-varnish, and 2 g / L CupT-FEVE-SiO2 aqueous solution against 1×10 5 The antibacterial properties of CFU / mL standard Aspergillus niger are as follows: Figure 10As shown in the figure, FEVE and varnish coatings alone do not have antibacterial properties. Both 2 g / L CupT-varnish and 2 g / L CupT-FEVE-SiO2 aqueous solution have anti-mildew effects, but the 2 g / L CupT-FEVE-SiO2 aqueous solution has the best anti-mildew effect (the largest diameter of the inhibition zone).

[0063] The experimental results of the above embodiments demonstrate that the present invention, through the preparation of a composite anti-mold coating, achieves highly efficient inhibition of both standard strain Aspergillus niger and drug-resistant strain Aspergillus niger. The final result shows that commonly available ordinary coatings (FEVE and varnish) have almost no anti-mold properties, while CuPT-FEVE-SiO2 exhibits a certain anti-mold effect, with particularly outstanding anti-mold performance against both standard and drug-resistant Aspergillus niger. A 1 g / L CuPT-FEVE-SiO2 aqueous solution is effective against bacterial cultures with a concentration of 1×10⁻⁶. 5 The antifungal rate of CFU / mL standard Aspergillus niger reached over 50%; a 3 g / L CuPT-FEVE-SiO2 aqueous solution was effective against bacterial cultures with a concentration of 1×10⁻⁶. 5 The antifungal rate of the CFU / mL standard Aspergillus niger reaches over 99.99%. The composite coating of this invention solves the problem of poor antifungal effect against Aspergillus niger and other molds at low material concentrations, as well as the problem of Aspergillus niger that has developed drug resistance at low material concentrations.

[0064] Example 5: Antibacterial experiment of CupT-FEVE-SiO2 and FEVE-SiO2 against standard strains 1. Experimental Procedure (1) Take 50 μL of a 3% FEVE aqueous solution and 50 μL of a 0.2 g / L CuPT-FEVE-SiO2 aqueous solution from Example 1, and drop them onto the surface of an untreated cedar block (2 cm long, 2 cm wide, and 0.5 cm high), respectively. Spread the solution evenly and allow it to air dry for 12 hours. Figure 19 As shown, the wooden block coated with 3% FEVE was designated as the control group (a), and the wooden block coated with CupT-FEVE-SiO2 was designated as the experimental group (b).

[0065] (2) Dissolve 0.2 g of SiO2-KH550 from Example 1 in 100 mL of 3% FEVE aqueous solution to obtain a milky white aqueous solution with a weight-volume ratio of 2 g / L, which is denoted as 2 g / L FEVE-SiO2.

[0066] (3) Take 50 μL of a 3% FEVE aqueous solution and 50 μL of FEVE-SiO2 with a solute concentration of 0.2 g / L, and drop them onto the surface of an untreated fir block (the block is 2 cm long, 2 cm wide, and 0.5 cm high), respectively. Spread the solution evenly and allow it to air dry for 12 hours. Figure 19 As shown, the wood block coated with 3% FEVE was designated as the control group (c), and the wood block coated with FEVE-SiO2 was designated as the experimental group (d).

[0067] (4) Take 0.1 mL of standard Aspergillus niger solution (strain number CMCC98003, purchased from Kaibei Technology (Suzhou) Co., Ltd.), and obtain a bacterial concentration of 1×10⁻⁶. 9 A certain amount of bacterial culture was taken from the concentration of CFU / mL and mixed with sterile phosphate buffered solution (PBS) to reduce the bacterial concentration to 1×10⁻⁶. 5 CFU / mL.

[0068] (5) Select a Sabouraud dextrose agar (SDA) medium with a diameter of 90 mm and a height of 15 mm, and use a sterile blade to cut two grooves with a length and width of 2 cm and a thickness of 0.5 cm on the surface of the agar.

[0069] (6) To compare the antifungal effects of different components, two parallel experiments were set up, and the specific procedures were as follows: Group 1: Place the wooden block previously coated with 3% FEVE (control group) in the empty slot on the left side of the first culture medium, and apply 30 μL of 3% FEVE emulsion around the gaps around the wooden block; place the wooden block previously coated with 2 g / L CupT-FEVE-SiO2 (experimental group) in the empty slot on the right side, and apply 30 μL of CupT-FEVE-SiO2 around the wooden block, and let it air dry.

[0070] Group 2: Place the wood block previously coated with 3% FEVE (control group) in the empty slot on the left side of the second culture medium, and apply 30 μL of 3% FEVE aqueous solution around the gaps of the wood block; place the wood block previously coated with 2 g / L FEVE-SiO2 (experimental group) in the empty slot on the right side, and apply 30 μL of FEVE-SiO2 around the wood block, and let it air dry naturally.

[0071] (7) Add 30 μL of 1×10⁻⁶ solution to the surface of the air-dried wood block. 5 CFU / mL standard Aspergillus niger was evenly coated onto the surface and sides of the wood block. Each concentration was tested in triplicate to eliminate errors. After coating, the blocks were placed in a 28°C incubator under ambient air and co-cultured with the Aspergillus niger and the wood block for 48 hours.

[0072] (8) Take out the petri dish and take a picture of the growth of the mold.

[0073] 2. Experimental Results (1) FEVE-SiO2 and CuPT-FEVE-SiO2 against 1×10 5 The antibacterial properties of CFU / mL standard Aspergillus niger are as follows: Figure 19 As shown in the figure, FEVE-SiO2 does not have antibacterial properties, while CuPT-FEVE-SiO2 exhibits a significant antibacterial effect.

[0074] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing a modified nano-silica reinforced fluorocarbon resin antibacterial coating, characterized in that, Includes the following steps: S11: Add nano-silica, pH adjuster and silane coupling agent to an alcohol aqueous solution and react at 110-130℃ for 10-14h to obtain the solid product SiO2-silane. S12: Add copper pyridinethione and the solid product SiO2-silane to water containing aqueous fluorocarbon resin emulsion, and mix to obtain the modified nano-silica reinforced fluorocarbon resin antibacterial coating.

2. The preparation method according to claim 1, characterized in that: In step S11, the mass ratio of nano-silica, pH adjuster and silane coupling agent is 10:1-2:

20.

3. The preparation method according to claim 1, characterized in that: The pH adjuster is triethylamine.

4. The preparation method according to claim 1, characterized in that: The aqueous fluorocarbon resin emulsion is an aqueous fluoroethylene-vinyl ether resin emulsion with a solid content of 45-50 wt%.

5. The preparation method according to claim 4, characterized in that: The mass ratio of copper pyridinethione, the solid product SiO2-silane, and the aqueous fluorocarbon resin emulsion is 1:1:3-3.

5.

6. The preparation method according to claim 4, characterized in that: In the water containing the aqueous fluorocarbon resin, the mass ratio of the aqueous fluorocarbon resin emulsion to water is 3-3.5:

97.

7. A modified nano-silica reinforced fluorocarbon resin antibacterial coating prepared by the preparation method according to any one of claims 1-6.

8. The application of the modified nano-silica reinforced fluorocarbon resin antibacterial coating according to claim 7 in wood protection.

9. The application of the modified nano-silica reinforced fluorocarbon resin antibacterial coating according to claim 8 in wood protection, characterized in that, The method of protecting wood includes applying the modified nano-silica reinforced fluorocarbon resin antibacterial coating to the surface of the wood to inhibit the growth of Aspergillus niger.

10. The application of the modified nano-silica reinforced fluorocarbon resin antibacterial coating according to claim 9 in wood protection, characterized in that, When the modified nano-silica reinforced fluorocarbon resin antibacterial coating is applied, the concentration of solute in the coating is 0.2-3 g / L.

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