Preparation method and application of Cu2O / TiO2 composite nano antibacterial coating

Abstract

The invention discloses a preparation method and application of a Cu2O / TiO2 composite nano antibacterial coating, the preparation method comprises the steps of preparation of Cu2O / TiO2 composite nano particles, preparation of a hydrophobic modified composite Cu2O / TiO2 particle suspension and preparation of the Cu2O / TiO2 composite nano antibacterial coating, and the preparation method can be applied to the fields of medical implant materials, food contact materials and building exterior wall materials. The prepared antibacterial coating breaks through the limitation of a single mechanism of a traditional antibacterial material, has self-cleaning, high durability and broad-spectrum antibacterial property, can effectively reduce the risk of drug-resistant bacterium infection, is suitable for medical implants, food contact materials, building exterior wall materials and other scenes, and has wide application prospects. The method has important scientific and application values for promoting the development of a composite antibacterial coating technology and guaranteeing public health safety.

Description

Technical Field

[0001] This invention relates to a method for preparing Cu2O / TiO2 composite nano-antibacterial coating and its application, belonging to the technical field of preparation and application of photocatalytic, self-cleaning, and antibacterial composite materials. Background Technology

[0002] In our daily lives, pathogenic microorganisms such as bacteria, viruses, and fungi are ubiquitous. These microorganisms are not only diverse in species but also reproduce extremely rapidly, easily inducing infections in humans and animals, leading to the widespread transmission of diseases. Among these, the risks posed by bacteria adhering to and contaminating material surfaces consistently have numerous adverse impacts on human health, medical procedures, and engineering applications. Infections caused by common drug-resistant bacteria such as Escherichia coli, Staphylococcus aureus, and Acinetobacter baumannii exhibit widespread and rampant spread, making drug-resistant bacterial infections one of the major global public health threats of the 21st century. Therefore, the development of antibacterial coatings to mitigate these risks has significant scientific research value and promising application prospects.

[0003] Superhydrophobic coatings, due to their superior anti-adhesion capabilities, can effectively inhibit the adhesion and accumulation of various contaminants on their surfaces, demonstrating significant application value in fields such as medical implant materials, environmentally friendly building coatings, and oil-water separation. However, whether superhydrophobic coatings prepared on different substrates possess the same excellent antibacterial adhesion properties remains to be verified. In fact, superhydrophobic antibacterial coatings face many challenges in practical applications, such as easy wear and poor durability.

[0004] Traditional antibacterial coatings are widely used in medical and food contact materials, but their long-term effectiveness is limited by inherent defects such as uncontrollable slow release of antibacterial agents, the risk of drug resistance evolution, and controversies regarding biocompatibility. Photocatalytic antibacterial coatings, due to their unique photocatalytic properties, not only show broad application prospects in novel non-drug-resistant antibacterial fields but can also solve some of the aforementioned problems of traditional antibacterial coatings. TiO2 is one of the key photocatalysts studied. As a commonly used photocatalytic coating material, its narrow light absorption width means it can only be excited by ultraviolet light to generate photocatalytic bactericidal ability. The resulting coatings suffer from poor practicality and susceptibility to photodegradation and corrosion, limiting its application development. Cu2O, as a commonly used inorganic bactericidal coating material, possesses highly efficient copper ion release bactericidal properties.

[0005] Research has found that introducing Cu2O to form pn-type Cu2O / TiO2 heterojunction nanomaterials can broaden the photoresponse range of nano-TiO2, extending its absorption width from the ultraviolet spectral region to the natural light region. Using composite Cu2O and TiO2 as nanophases, hydrophobic modification with modifiers is employed to prepare composite Cu2O / TiO2 coatings. This not only combines the synergistic effects of TiO2 photocatalytic bactericidal action and Cu2O release bactericidal action to improve the coating's bactericidal performance, but also allows for precise control of the complex micro / nanostructures on the coating surface to achieve superhydrophobic antibacterial adhesion properties of the Cu2O / TiO2 coating.

[0006] The adhesion and contamination of material surfaces by pathogenic bacteria serves as the initial stage in the development of infectious diseases, and the subsequent formation of biofilms poses a significant challenge to modern medicine. Existing Cu2O / TiO2 composite superhydrophobic antibacterial coatings, release-type bactericidal coatings, and photocatalytic antibacterial coatings all exhibit good antibacterial properties. However, while superhydrophobic coatings can inhibit early bacterial adhesion and effectively resist bacterial attachment in the early stages of use, they still suffer from insufficient structural stability and poor durability over long-term use, leading to a decline in antifouling performance and the emergence of bacterial contamination. Although release-type antibacterial coatings can effectively kill bacteria, they suffer from uncontrollable antibacterial agent release, secondary environmental pollution, and low bactericidal efficiency. While photocatalytic bactericidal coatings possess excellent bactericidal efficiency, their development is limited by issues such as poor stability of photodynamic materials in practical applications.

[0007] Superhydrophobic properties can be achieved by precisely controlling the complex micro / nanostructure of the Cu2O / TiO2 coating surface, enabling its application in photocatalysis and antibacterial fields. However, Cu2O / TiO2 composite coatings still face several challenges in practical applications. On the one hand, the coating's poor penetration into the substrate weakens its adhesion, making it prone to peeling under mechanical wear and environmental corrosion. On the other hand, the bonding between nanoparticles and the substrate is not tight enough; the lack of strong chemical bonds between the nanoparticles and the substrate makes the coating susceptible to detachment from external impacts, leading to rapid failure of its superhydrophobic properties. These two aspects limit the effectiveness and durability of the coating. Although these problems can be addressed by continuously repairing the surface coating, the resulting economic costs, energy consumption, and the complex operations involved in frequent repairs are difficult to estimate, limiting its large-scale practical application.

[0008] Furthermore, although the active free radicals generated by photoexcitation of the Cu2O / TiO2 composite coating can effectively decompose bacteria and organic pollutants, this process may also damage the long-chain hydrophobic groups on the coating surface, thus affecting its durability and service life. Moreover, with prolonged use, the coating may suffer from aging and natural light corrosion, all of which weaken its antibacterial adhesion function and reduce its durability. Therefore, how to further improve the surface structure of the coating, enhance the adhesion between the coating and the substrate, and thus improve the coating's durability is one of the key issues of this research.

[0009] In recent years, the preparation of antibacterial multifunctional coatings for application on various substrate surfaces has become a research hotspot, as these excellent properties give the coatings broad application prospects in antibacterial applications. Therefore, there is an urgent need to develop self-cleaning antibacterial coatings that are durable, stable, free from secondary pollution, and suitable for large-scale application. Summary of the Invention

[0010] To address the shortcomings of the existing technologies, the present invention aims to prepare a coating that overcomes the limitations of the single performance of traditional antibacterial materials. The resulting coating combines self-cleaning, high durability, and broad-spectrum antibacterial properties, effectively reducing the risk of infection by drug-resistant bacteria. It is suitable for applications such as medical implants, food contact materials, and building exterior wall materials, and has significant scientific and application value for promoting the development of composite antibacterial coating technology and ensuring public health and safety.

[0011] This invention provides a method for preparing a Cu2O / TiO2 composite nano-antibacterial coating, comprising the following steps:

[0012] (1) Preparation of Cu2O / TiO2 composite nanoparticles: CuSO4·5H2O was dissolved in deionized water, and after stirring and dissolving, P25 particles were added. After stirring evenly, the mixture was quickly poured into a solution of reducing agent and protective agent. The mixture was heated and stirred in a water bath, and then centrifuged, ultrasonically cleaned and dried to obtain Cu2O / TiO2 composite nanoparticles.

[0013] (2) Preparation of hydrophobic modified composite Cu2O / TiO2 particle suspension: PFDTES is added to anhydrous ethanol and magnetically stirred until PFDTES is completely hydrolyzed. The Cu2O / TiO2 composite nanoparticles from step (1) are added and magnetically stirred to mix evenly to obtain hydrophobic modified composite Cu2O / TiO2 particle suspension.

[0014] (3) Preparation of Cu2O / TiO2 composite nano antibacterial coating: Liquid lithium silicate is evenly dropped onto a clean glass slide using a dropper, and then evenly coated with a silicone brush. After standing and curing, a semi-cured adhesive substrate is obtained. The hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) is evenly sprayed, dropped, or dipped onto the surface of the semi-cured adhesive substrate, and then dried at room temperature to obtain the Cu2O / TiO2 composite nano antibacterial coating.

[0015] Furthermore, as a more preferred embodiment of the present invention, in step (1), the method for preparing the reducing agent and protective agent mixed solution is as follows: PVP and C6H8O6 are added to deionized water, stirred and dissolved, and NaOH and H2SO4 are added to adjust the pH value to 10.8-11.2; the mass ratio of PVP, C6H8O6 and deionized water is 1:(3.95-4.05):(195-205).

[0016] Furthermore, as a more preferred embodiment of the present invention, in step (1), the mass ratio of CuSO4·5H2O to P25 particles is (2.8~3.3):(6.6~7.3).

[0017] Furthermore, as a more preferred embodiment of the present invention, in step (1), the temperature of the water bath heating and stirring dissolution is 79-81°C, and the stirring speed is 98-105 r / min.

[0018] Furthermore, as a more preferred embodiment of the present invention, in step (1), the centrifuge speed during centrifugal separation is 1900-2100 rpm.

[0019] Furthermore, as a more preferred embodiment of the present invention, in step (1), the ultrasonic cleaning is performed by first ultrasonically cleaning twice with deionized water and then ultrasonically cleaning once with anhydrous ethanol.

[0020] Furthermore, as a more preferred embodiment of the present invention, in step (1), the drying is performed in a vacuum freeze dryer for 11.7 to 12.5 hours.

[0021] Furthermore, as a more preferred embodiment of the present invention, in step (2), the mass ratio of PFDTES and Cu2O / TiO2 composite nanoparticles is (0.95~1.1):(9.8~10.3); the magnetic stirring time is 55~63 min.

[0022] Furthermore, as a more preferred embodiment of the present invention, in step (3), the static curing time is 9 to 11 minutes; the room temperature drying time is 23 to 25 hours.

[0023] Furthermore, as a more preferred embodiment of the present invention, in step (3), the spraying is to uniformly spray the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) onto the semi-cured adhesive substrate three times at a distance of 20-25 cm above the semi-cured adhesive substrate using a sprayer; the drip coating is to uniformly drip the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) onto the surface of the semi-cured substrate, and to slightly shake the substrate during the drip coating process to ensure uniform coating coverage, and the suspension naturally flows and levels under the gravity of the substrate surface; the dip coating is to immerse the semi-cured adhesive substrate in the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) three times, with each immersion time being 3-5 seconds.

[0024] Furthermore, as a more preferred embodiment of the present invention, the Cu2O / TiO2 composite nano-antibacterial coating prepared by the above-described method is applied in medical implant materials, food contact materials, and building exterior wall materials.

[0025] In this application, the preparation of antibacterial coatings using hydrophobically modified composite Cu2O / TiO2 particle suspensions can be achieved through three methods: spraying, dripping, and dipping. The mass ratio of PFDTES to Cu2O / TiO2 composite nanoparticles and the different preparation methods of the antibacterial coating have a slight impact on the product. When the amount of Cu2O / TiO2 composite nanoparticles added is 1.5g and the amount of PFDTES hydrophobic modifier added is 150μL, that is, when the mass ratio of PFDTES to Cu2O / TiO2 composite nanoparticles is 3:7, the antibacterial coating prepared by spraying has the best superhydrophobic properties. The introduction of dual-scale Cu2O / TiO2 composite nanoparticles successfully constructs the micro-nano structure of the coating, increases the surface roughness of the coating, and results in the best hydrophobic properties. The particles on the coating surface are evenly distributed, and the hydrophobic angle reaches 151.3°.

[0026] Experimental screening process:

[0027] 1. Amount of Cu2O / TiO2 composite nanoparticles added

[0028] The amount of nanoparticles added to a coating has a specific impact on the surface morphology. Excessive nanoparticle addition may lead to powdering and cracking of the coating. This study will investigate the effect of nanoparticle addition on the surface morphology of the composite coating, providing a foundation for subsequent coating performance research.

[0029] The amount of Cu2O / TiO2 composite nanoparticles added is shown in Table 1. Different amounts of Cu2O / TiO2 composite nanoparticles were accurately weighed and stirred in a mixture of modifier and ethanol for 2 hours. The fully reacted Cu2O / TiO2 composite nano antibacterial coating was then evenly sprayed onto the substrate using a sprayer to prepare the coating.

[0030] Table 1. Cu₂O / TiO₂ composite particle addition amount

[0031] Sample number 1 2 3 4 5 Particle addition amount (g) 0.5 1.0 1.5 2 2.5

[0032] Experimental results are as follows Figure 10 , Figure 11 As shown, the surface morphology and hydrophobic properties of the coating are compared under different nanoparticle addition conditions.

[0033] When the amount of Cu2O / TiO2 composite nanoparticles added is 0.5g, the concentration of nanoparticles in the modified suspension is low, resulting in the substrate not being completely covered by the composite particles. At this time, water droplets can form an approximately spherical shape on the surface of the coating, but they do not perform well in terms of rolling off.

[0034] When the Cu2O / TiO2 composite nanoparticles were increased to 1.0 g, the uniformity of the coating surface was significantly improved. Water droplets formed near-spherical shapes in most areas of the coating and could easily roll off, indicating that the integrity of the coating was significantly enhanced.

[0035] When the amount of Cu2O / TiO2 composite nanoparticles added is 1.5g, the water droplets on the coating surface still remain spherical, and the hydrophobic properties are good.

[0036] When the Cu2O / TiO2 composite nanoparticles are added at amounts of 2.0 g and 2.5 g, the prepared coating surface can maintain a near-spherical shape. However, when tilted and rolled, some of the nanoparticles that have detached from the coating surface due to pulverization and cracking are carried away, resulting in a significant decrease in coating performance. Therefore, high-addition-amount coatings are not feasible in practical applications.

[0037] Therefore, the amount of Cu2O / TiO2 composite nanoparticles added has a significant impact on the cracking phenomenon of the coating. During the drying process, when the amount of Cu2O / TiO2 nanoparticles added exceeds the appropriate range, the coating thickness increases accordingly, and the internal stress also rises, causing mutual adsorption and aggregation between nanoparticles, thus affecting the overall curing rate of the coating and exacerbating the cracking phenomenon. In summary, when the amount of Cu2O / TiO2 composite nanoparticles added is 1.5g, the prepared coating has the most uniform surface morphology and the best hydrophobic properties.

[0038] 2. The Influence of Different Manufacturing Methods on Coatings

[0039] Liquid lithium silicate was evenly dropped onto several clean glass slides using a dropper, spread evenly with a silicone brush, and allowed to cure for 10 minutes. Hydrophobic modified Cu₂O / TiO₂ composite coatings were prepared using spraying, drop coating, and dip coating methods respectively. The coatings were allowed to cure at room temperature, and the morphology of water droplets on the coating surface and the rolling off of droplets after tilting the coating were observed to evaluate the coating performance. The three coating preparation methods are detailed below:

[0040] ① Spraying method: Spray three coats of dual-scale hydrophobic modified Cu2O / TiO2 particle suspension evenly onto the semi-cured adhesive substrate at a height of 20-25cm above the substrate.

[0041] ② Drop coating method: Apply an appropriate amount of dual-scale hydrophobic modified Cu2O / TiO2 particle suspension evenly to the surface of the semi-cured substrate. To ensure uniform coating coverage, gently shake the surface and allow the droplets to flow naturally under the influence of gravity.

[0042] ③ Dip coating method: Immerse the substrate to be coated with the adhesive in a suspension of hydrophobically modified Cu2O / TiO2 particles for 3-5 seconds. To ensure uniform coating coverage, repeat this dip coating process 3 times.

[0043] Cu2O / TiO2 composite nano-antibacterial coatings prepared by different methods were dried at room temperature for 24 hours before subsequent experiments were conducted.

[0044] Experimental results are as follows Figure 12 , Figure 13 As shown in the figure, the surface morphologies of the hydrophobic modified Cu2O / TiO2 composite coatings prepared by the drop coating, dip coating, and spray coating methods are quite different. The drop coating prepared by the drop coating method has particle agglomeration on the surface, resulting in local unevenness and obvious cracking after drying. Droplets will collapse in areas of uneven coating on the surface, gradually wetting the surface of the coating and causing a decrease in the hydrophobicity of the coating.

[0045] Dip coating is difficult to control accurately in terms of coating thickness and uniformity. Uneven distribution of nanoparticles during preparation leads to variations in nanoparticle concentration in different areas. These differences in curing rate cause cracking, exposing the lithium silicate substrate and reducing coating performance. Furthermore, during dip coating, excess coating flows and distributes evenly on the substrate surface due to gravity or liquid surface tension, hindering the formation of micro / nano structures on the coating surface. In contrast, coatings produced by spraying exhibit a flawless and continuous surface, free from cracks, peeling, or irregularities. Water droplets falling on the coating surface form near-spherical shapes and roll easily when tilted.

[0046] In this application, the photocatalytic antibacterial mechanism is a process of killing microorganisms by utilizing redox-active species generated by semiconductor materials (such as TiO2, Cu2O, ZnO, etc.) under light radiation; the self-cleaning mechanism is the function of the coating to reduce the adhesion of pollutants and promote their degradation through surface physical properties or chemical action; the ion release antibacterial mechanism is the release of metal ions (such as CuSAg). + Cu 2+ Zn 2+ Antibacterial methods that disrupt the metabolic function of microorganisms (e.g., etc.).

[0047] This application uses CuSO4·5H2O as the copper source and P25 as the titanium source to synthesize Cu2O / TiO2 composite nanoparticles via an impregnation-chemical reduction method. Focusing on the construction of an antibacterial coating with a "photocatalytic, self-cleaning, and ion release triple mechanism," the study investigates the effects of Cu2O / TiO2 nanoparticle doping, PFDTES hydrophobic modifier dosage, coating preparation method, and Cu2O / TiO2 mass ratio on the surface morphology and hydrophobic effect of the superhydrophobic antibacterial coating. This aims to optimize the preparation process parameters of the Cu2O / TiO2 superhydrophobic composite nano-antibacterial coating and achieve multifunctional synergistic antibacterial properties. Furthermore, the study focuses on analyzing the influence of different PFDTES hydrophobic agent dosages and different Cu2O / TiO2 mass ratios on the micro / nano dual-scale structure of the Cu2O / TiO2 composite superhydrophobic antibacterial coating. The main research results are as follows:

[0048] (1) Micro-nano structure regulation and performance optimization of Cu2O / TiO2 superhydrophobic composite coating: By adjusting the Cu2O / TiO2 ratio and the amount of PFDTES, a dual-scale micro-nano rough structure was constructed, which significantly improved the hydrophobicity and mechanical durability of the coating. When the mass ratio of Cu2O / TiO2 was 3:7, the clustered layered structure formed by the dual-scale particles increased the surface roughness (Ra=757.8nm) by 50 times, and the hydrophobic performance was the best. When the amount of Cu2O / TiO2 composite nanoparticles added was 1.5g and the amount of PFDTES hydrophobic modifier added was 150μL, the hydrophobic groups of the coating were saturated, the contact angle tended to be stable, and the coating prepared by spraying had the best superhydrophobic performance. The particles on the coating surface were uniformly distributed and the structure was stable, and the hydrophobic angle reached the optimal value of 151.3°.

[0049] (2) The coating prepared with an addition of 1.5g of Cu2O / TiO2 composite particles exhibited a uniform surface morphology and stable hydrophobic properties. Coatings with insufficient nanoparticle addition were not completely covered by low surface energy particles, resulting in poor hydrophobic properties. During the drying process, when the addition of Cu2O / TiO2 nanoparticles exceeded the appropriate range, mutual adsorption and agglomeration between nanoparticles occurred, leading to pulverization and flaking, thus reducing the integrity of the coating surface. The coating prepared by the drop coating method showed particle agglomeration and localized unevenness, resulting in poor hydrophobicity. The coating prepared by the dip coating method exhibited severe surface cracking and pulverization, exhibiting the worst hydrophobic properties. The coating prepared by the spray coating method had an intact and continuous surface, exhibiting the best hydrophobic properties.

[0050] (3) The contact angle of the coating after modification with the addition of modifier increases with the increase of PFDTES dosage. After the PFDTES dosage is increased to 150 μL, the contact angle of the coating no longer increases significantly because the modified hydrophobic groups on the coating surface tend to be saturated.

[0051] This application uses *Escherichia coli* and *Staphylococcus aureus* as representative strains of Gram-positive and Gram-negative bacteria, respectively, as typical experimental bacteria. The plate count method was employed to investigate the self-cleaning, antibacterial adhesion, ion release bactericidal, and photocatalytic bactericidal properties of the multifunctional superhydrophobic coating. The study delved into the photocatalytically active species of the antibacterial coating, the coating's ion release characteristics, and the breakthroughs in the synergistic antibacterial performance through multiple mechanisms of self-cleaning, ion release, and photocatalysis. The results confirm that the coating possesses both long-lasting anti-adhesion and highly efficient bactericidal properties. The main research results are as follows:

[0052] (1) The composite antibacterial coating showed good stable antibacterial adhesion performance in long-term cyclic experiments: after 20 bacterial adhesion cycles, the anti-adhesion rate of the coating against Escherichia coli and Staphylococcus aureus remained above 85%, and the quality retention rate remained above 99.5%; after simple rinsing with physiological saline, the composite antibacterial coating can significantly inhibit the adhesion of most bacteria without the risk of secondary environmental pollution.

[0053] (2) The composite coating exhibits excellent natural light-responsive bactericidal performance: After 6 hours of natural light irradiation, the CT010 coating showed bactericidal rates of 82.56% and 94.11% against Escherichia coli and Staphylococcus aureus, respectively. The Cu2O-doped composite coating showed a significantly improved natural light-catalyzed bactericidal rate. The CT37 coating achieved a bactericidal rate of over 99.9% against both bacteria, and after 20 bactericidal cycles, the CT37 coating maintained a bactericidal rate of over 85% against both bacteria. This reveals a synergistic mechanism of "superhydrophobic barrier - initial ion bactericidal action - sustained photocatalytic antibacterial action": the superhydrophobic surface reduces initial bacterial adhesion, Cu2O... 2+ Rapid release inhibits early reproduction, and the photocatalytically generated reactive oxygen species (ROS) achieve long-term and efficient sterilization, while the release rate of copper ions is safe and controllable.

[0054] (3) Synergistic antibacterial mechanism of three types of effects of superhydrophobic antibacterial coating: The superhydrophobic properties and early copper ion release of the composite antibacterial coating effectively inhibit the initial adhesion and reproduction of bacteria. The ROS generated by the composite coating in conjunction with natural light excitation ensures the long-term high efficiency of the coating in bactericidal performance. The copper ion release rate of the composite antibacterial coating decreases over time, and the maximum release rate is far lower than the safe rate of daily copper ion intake for humans. The composite antibacterial coating exhibits good synergistic antibacterial effects of self-cleaning, ion release bactericidal and photocatalytic bactericidal.

[0055] Compared with the prior art, the technical solution of this application has the following beneficial effects:

[0056] (1) This application uses an impregnation-chemical reduction method to prepare Cu2O / TiO2 composite nanoparticles, with 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES) as a modifier and lithium silicate as a binder. A superhydrophobic antibacterial coating is then prepared using spraying, drop coating, or impregnation methods. This application investigates the influence of the surface microstructure and physicochemical composition of the composite coating on its durability and self-cleaning properties. It also discusses the main active species, metal ion release, and self-cleaning effects during the photocatalytic process of the coating, proposing a synergistic bactericidal mechanism of self-cleaning, metal ion release, and photocatalysis.

[0057] (2) This application utilizes a two-step spraying technique to prepare a multifunctional Cu2O / TiO2 superhydrophobic antibacterial coating to expand the practical application range of Cu2O / TiO2 composite materials. By exploring the preparation method and optimal process conditions of the natural light-responsive superhydrophobic Cu2O / TiO2 antibacterial coating, a superhydrophobic coating with excellent properties such as self-cleaning, high durability, and bactericidal activity was prepared. This coating can effectively reduce the risk of infection by drug-resistant bacteria and achieve a synergistic antibacterial effect of self-cleaning, ion release, and photocatalysis. This further promotes the development of composite antibacterial coating technology and has important scientific significance and application value.

[0058] (3) The antibacterial coating prepared in this application breaks through the limitations of the single mechanism of traditional antibacterial materials. It has the characteristics of self-cleaning, high durability and broad-spectrum antibacterial properties, which can effectively reduce the risk of infection by drug-resistant bacteria. It is suitable for medical implants, food contact materials, building exterior wall materials and other scenarios. It has important scientific and application value for promoting the development of composite antibacterial coating technology and ensuring public health safety. Attached Figure Description

[0059] Figure 1 This is a process flow diagram for preparing the Cu2O / TiO2 composite nano-antibacterial coating of the present invention;

[0060] Figure 2 Typical plate images showing the antibacterial effects of different composite antibacterial coatings after 6 hours of light avoidance: blank; CT010; CT28; CT37; CT46;

[0061] Figure 3 Bar chart showing the relative bacterial survival rates of different composite antibacterial coatings after 6 hours of light avoidance;

[0062] Figure 4 Typical plate images showing the antibacterial effects of different composite antibacterial coatings after 6 hours of exposure to natural light: blank; light exposure; CT010; CT28; CT37; CT46;

[0063] Figure 5 Bar chart showing the relative bacterial survival rates of different composite antibacterial coatings after 6 hours of exposure to natural light;

[0064] Figure 6 Typical plate images showing the antibacterial adhesion effect of composite antibacterial coatings with different Cu2O / TiO2 mass ratios: blank; CT010; CT28; CT37; CT46;

[0065] Figure 7 Bar chart showing the number of bacteria adhering to the antibacterial adhesion effect of composite antibacterial coatings with different Cu2O / TiO2 mass ratios;

[0066] Figure 8 A bar chart showing the relative antibacterial adhesion rate of composite antibacterial coatings with different Cu2O / TiO2 mass ratios;

[0067] Figure 9 SEM images of the Cu2O / TiO2 composite nano-antibacterial coating prepared by the method of the present invention: (a) CT010, (b) CT28, (c) CT37, (d) CT46;

[0068] Figure 10 Surface morphology of antibacterial coatings with different amounts of Cu2O / TiO2 composite nanoparticles;

[0069] Figure 11 The effect of different Cu2O / TiO2 composite nanoparticle addition amounts on the contact angle of the composite antibacterial coating is shown in the following figures: (a) 0; (b) 0.50; (c) 1.5; (d) 2.0.

[0070] Figure 12 Figure 1 shows the effect of different manufacturing methods on the surface morphology of the composite antibacterial coating: (a) spraying method (b) drop coating method (c) dip coating method;

[0071] Figure 13 The effect of different manufacturing methods on the contact angle of the composite antibacterial coating is shown in the following figures: (a) spraying method (b) drop coating method (c) dip coating method;

[0072] Figure 14This is a graph showing the trend of contact angle and rolling angle changes of sample CT73 after wear cycles obtained in Example 7 of the present invention;

[0073] Figure 15 This is a graph showing the trend of contact angle and roll-off angle of sample CT73 obtained in Example 7 of the present invention in air;

[0074] Figure 16 This is a graph showing the trend of coating contact angle change of sample CT73 obtained in Example 7 of the present invention after immersion in solutions of different pH values;

[0075] Figure 17 This is a graph showing the trend of coating roll-off angle change of sample CT73 obtained in Example 7 of the present invention after immersion in solutions of different pH values;

[0076] Figure 18 This is a graph showing the trend of contact angle and roll-off angle changes of sample CT73 obtained in Example 7 of the present invention after immersion in physiological saline.

[0077] Figure 19 This is a graph showing the trend of contact angle and roll-off angle changes of sample CT73 obtained in Example 7 of the present invention after natural light aging;

[0078] Figure 20 This is a graph showing the trend of F element content change in the coating of sample CT73 obtained in Example 7 of the present invention after natural light aging;

[0079] Figure 21 Comparison of the hydrophobicity of sample CT73 prepared in Example 7 of this invention on different substrates: (a) glass slide, (b) wood chip, (c) stainless steel, (d) zinc sheet;

[0080] Figure 22 The following are images showing the self-cleaning performance test results of sample CT73 prepared in Example 7 of this invention on different substrates: (a) glass slide, (b) wood chip, (c) zinc sheet, and (d) stainless steel. Detailed Implementation

[0081] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0082] The present invention provides a method for preparing a Cu2O / TiO2 composite nano-antibacterial coating, comprising the following steps:

[0083] (1) Preparation of Cu2O / TiO2 composite nanoparticles: CuSO4·5H2O was dissolved in deionized water, and after stirring and dissolving, P25 particles were added. After stirring evenly, the mixture was quickly poured into a solution of reducing agent and protective agent. The mixture was heated and stirred in a water bath, and then centrifuged, ultrasonically cleaned and dried to obtain Cu2O / TiO2 composite nanoparticles.

[0084] (2) Preparation of hydrophobic modified composite Cu2O / TiO2 particle suspension: PFDTES is added to anhydrous ethanol and magnetically stirred until PFDTES is completely hydrolyzed. The Cu2O / TiO2 composite nanoparticles from step (1) are added and magnetically stirred to mix evenly to obtain hydrophobic modified composite Cu2O / TiO2 particle suspension.

[0085] (3) Preparation of Cu2O / TiO2 composite nano antibacterial coating: Liquid lithium silicate is evenly dropped onto a clean glass slide using a dropper, and then evenly coated with a silicone brush. After standing and curing, a semi-cured adhesive substrate is obtained. The hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) is evenly sprayed, dropped, or dipped onto the surface of the semi-cured adhesive substrate, and then dried at room temperature to obtain the Cu2O / TiO2 composite nano antibacterial coating.

[0086] Specifically, in this embodiment of the invention, in step (1), the method for preparing the reducing agent and protective agent mixed solution is as follows: PVP and C6H8O6 are added to deionized water, stirred and dissolved, and NaOH and H2SO4 are added to adjust the pH value to 10.8-11.2; the mass ratio of PVP, C6H8O6 and deionized water is 1:(3.95-4.05):(195-205).

[0087] Specifically, in this embodiment of the invention, in step (1), the mass ratio of CuSO4·5H2O to P25 particles is (2.8-3.3):(6.6-7.3).

[0088] Specifically, in this embodiment of the invention, in step (1), the temperature of the water bath heating and stirring for dissolution is 79-81°C, and the stirring speed is 98-105 r / min.

[0089] Specifically, in this embodiment of the invention, in step (1), the speed of the centrifuge during centrifugal separation is 1900 to 2100 rpm.

[0090] Specifically, in this embodiment of the invention, in step (1), ultrasonic cleaning is performed by first ultrasonically cleaning twice with deionized water and then ultrasonically cleaning once with anhydrous ethanol.

[0091] Specifically, in this embodiment of the invention, in step (1), drying is performed in a vacuum freeze dryer for 11.7 to 12.5 hours.

[0092] Specifically, in this embodiment of the invention, in step (2), the mass ratio of PFDTES and Cu2O / TiO2 composite nanoparticles is (0.95~1.1):(9.8~10.3); the magnetic stirring time is 55~63min.

[0093] Specifically, in this embodiment of the invention, in step (3), the static curing time is 9 to 11 minutes; the room temperature drying time is 23 to 25 hours.

[0094] Specifically, in this embodiment of the invention, in step (3), spraying involves uniformly spraying the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) onto the semi-cured adhesive substrate three times at a distance of 20-25 cm above the substrate using a sprayer; drop coating involves uniformly dropping the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) onto the surface of the semi-cured substrate, gently shaking the substrate during the drop coating process to ensure uniform coating coverage, and allowing the suspension to flow naturally under the influence of gravity on the substrate surface; dip coating involves immersing the semi-cured adhesive substrate in the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) three times, with each immersion time being 3-5 seconds.

[0095] Specifically, in the embodiments of the present invention, the Cu2O / TiO2 composite nano antibacterial coating prepared by the above-described method is applied in medical implant materials, food contact materials, and building exterior wall materials.

[0096] The Cu2O / TiO2 composite nano-antibacterial coating prepared in this application was subjected to electron microscopy scanning, and SEM images of the Cu2O / TiO2 composite nano-antibacterial coating were obtained. The results are as follows. Figure 9 As shown.

[0097] Example 1

[0098] like Figure 1 As shown, a method for preparing a Cu2O / TiO2 composite nano-antibacterial coating includes the following steps:

[0099] (1) Preparation of Cu2O / TiO2 composite nanoparticles: CuSO4·5H2O was dissolved in deionized water, and after stirring and dissolving, P25 particles were added. After stirring evenly, the mixture was quickly poured into a solution of reducing agent and protective agent. The mixture was heated in a water bath at 79°C and stirred at 98 r / min. After centrifugation at 1900 rpm, ultrasonic cleaning, and drying in a vacuum freeze dryer for 11.7 h, Cu2O / TiO2 composite nanoparticles were obtained.

[0100] The preparation method of the reducing agent and protective agent mixed solution is as follows: PVP and C6H8O6 are added to deionized water, stirred and dissolved, and NaOH and H2SO4 are added to adjust the pH value to 10.8; the mass ratio of PVP, C6H8O6 and deionized water is 1:3.95:195; the mass ratio of CuSO4·5H2O and P25 particles is 2.8:6.6; ultrasonic cleaning is performed by first ultrasonically cleaning twice with deionized water and then ultrasonically cleaning once with anhydrous ethanol.

[0101] (2) Preparation of hydrophobic modified composite Cu2O / TiO2 particle suspension: PFDTES is added to anhydrous ethanol and magnetically stirred until PFDTES is completely hydrolyzed. The Cu2O / TiO2 composite nanoparticles from step (1) are added and magnetically stirred to mix evenly to obtain hydrophobic modified composite Cu2O / TiO2 particle suspension.

[0102] The mass ratio of PFDTES to Cu2O / TiO2 composite nanoparticles was 0.95:9.8; the magnetic stirring time was 55 min for all samples.

[0103] (3) Preparation of Cu2O / TiO2 composite nano antibacterial coating: Liquid lithium silicate is evenly dropped onto a clean glass slide using a dropper, and then evenly coated with a silicone brush. After standing and curing for 9 minutes, a semi-cured adhesive substrate is obtained. The hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) is evenly sprayed, dropped, or dipped onto the surface of the semi-cured adhesive substrate, and then dried at room temperature for 23 hours to obtain the Cu2O / TiO2 composite nano antibacterial coating.

[0104] In step (3), spraying involves uniformly spraying the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) onto the semi-cured adhesive substrate three times from 20cm above the substrate using a sprayer; drop coating involves uniformly dropping the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) onto the surface of the semi-cured substrate, gently shaking the substrate during the drop coating process to ensure uniform coating coverage, and allowing the suspension to flow naturally under the influence of gravity on the substrate surface; dip coating involves immersing the semi-cured adhesive substrate in the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) three times, with each immersion time being 3 seconds.

[0105] Specifically, the Cu2O / TiO2 composite nano-antibacterial coating prepared by the above-described method is applied in medical implant materials, food contact materials, and building exterior wall materials.

[0106] Example 2

[0107] like Figure 1 As shown, a method for preparing a Cu2O / TiO2 composite nano-antibacterial coating includes the following steps:

[0108] (1) Preparation of Cu2O / TiO2 composite nanoparticles: CuSO4·5H2O was dissolved in deionized water, and after stirring and dissolving, P25 particles were added. After stirring evenly, the mixture was quickly poured into a solution of reducing agent and protective agent. The mixture was heated in a water bath at 81°C and stirred at 105r / min. After centrifugation at 2100rpm, ultrasonic cleaning, and drying in a vacuum freeze dryer for 12.5h, Cu2O / TiO2 composite nanoparticles were obtained.

[0109] The preparation method of the reducing agent and protective agent mixed solution is as follows: PVP and C6H8O6 are added to deionized water, stirred and dissolved, and NaOH and H2SO4 are added to adjust the pH value to 11.2; the mass ratio of PVP, C6H8O6 and deionized water is 1:4.05:205; the mass ratio of CuSO4·5H2O and P25 particles is 3.3:7.3; ultrasonic cleaning is performed by first ultrasonically cleaning twice with deionized water and then ultrasonically cleaning once with anhydrous ethanol.

[0110] (2) Preparation of hydrophobic modified composite Cu2O / TiO2 particle suspension: PFDTES is added to anhydrous ethanol and magnetically stirred until PFDTES is completely hydrolyzed. The Cu2O / TiO2 composite nanoparticles from step (1) are added and magnetically stirred to mix evenly to obtain hydrophobic modified composite Cu2O / TiO2 particle suspension.

[0111] The mass ratio of PFDTES to Cu2O / TiO2 composite nanoparticles was 1.1:10.3; the magnetic stirring time was 63 min for both.

[0112] (3) Preparation of Cu2O / TiO2 composite nano antibacterial coating: Liquid lithium silicate is evenly dropped onto a clean glass slide using a dropper, and then evenly coated with a silicone brush. After standing and curing for 11 minutes, a semi-cured adhesive substrate is obtained. The hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) is evenly sprayed, dropped, or dipped onto the surface of the semi-cured adhesive substrate, and then dried at room temperature for 25 hours to obtain the Cu2O / TiO2 composite nano antibacterial coating.

[0113] In step (3), spraying involves uniformly spraying the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) onto the semi-cured adhesive substrate three times from a distance of 25 cm above the substrate; drop coating involves uniformly dropping the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) onto the surface of the semi-cured substrate, gently shaking the substrate during the drop coating process to ensure uniform coating coverage, and allowing the suspension to flow naturally under the influence of gravity on the substrate surface; dip coating involves immersing the semi-cured adhesive substrate in the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) three times, with each immersion time being 5 seconds.

[0114] Specifically, the Cu2O / TiO2 composite nano-antibacterial coating prepared by the above-described method is applied in medical implant materials, food contact materials, and building exterior wall materials.

[0115] Example 3

[0116] like Figure 1 As shown, a method for preparing a Cu2O / TiO2 composite nano-antibacterial coating includes the following steps:

[0117] (1) Preparation of Cu2O / TiO2 composite nanoparticles: CuSO4·5H2O was dissolved in deionized water, and after stirring and dissolving, P25 particles were added. After stirring evenly, the mixture was quickly poured into a solution of reducing agent and protective agent. The mixture was heated in a water bath at 80.5℃ and stirred at 104r / min. Then, it was centrifuged at 2050rpm, ultrasonically cleaned, and dried in a vacuum freeze dryer for 12.3h to obtain Cu2O / TiO2 composite nanoparticles.

[0118] The preparation method of the reducing agent and protective agent mixed solution is as follows: PVP and C6H8O6 are added to deionized water, stirred and dissolved, and NaOH and H2SO4 are added to adjust the pH value to 10.9; the mass ratio of PVP, C6H8O6 and deionized water is 1:4.03:203; the mass ratio of CuSO4·5H2O and P25 particles is 3.2:7.2; ultrasonic cleaning is performed by first ultrasonically cleaning twice with deionized water and then ultrasonically cleaning once with anhydrous ethanol.

[0119] (2) Preparation of hydrophobic modified composite Cu2O / TiO2 particle suspension: PFDTES is added to anhydrous ethanol and magnetically stirred until PFDTES is completely hydrolyzed. The Cu2O / TiO2 composite nanoparticles from step (1) are added and magnetically stirred to mix evenly to obtain hydrophobic modified composite Cu2O / TiO2 particle suspension.

[0120] The mass ratio of PFDTES to Cu2O / TiO2 composite nanoparticles was 1.05:10.2; the magnetic stirring time was 62 min for both.

[0121] (3) Preparation of Cu2O / TiO2 composite nano antibacterial coating: Liquid lithium silicate is evenly dropped onto a clean glass slide using a dropper, and then evenly coated with a silicone brush. After standing and curing for 10.5 min, a semi-cured adhesive substrate is obtained. The hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) is evenly sprayed, dropped, or dipped onto the surface of the semi-cured adhesive substrate, and then dried at room temperature for 24.5 h to obtain the Cu2O / TiO2 composite nano antibacterial coating.

[0122] In step (3), spraying involves spraying the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) onto the semi-cured adhesive substrate three times using a sprayer at a distance of 24 cm above the substrate; drop coating involves uniformly dropping the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) onto the surface of the semi-cured substrate, gently shaking the substrate during the drop coating process to ensure uniform coating coverage, and allowing the suspension to flow naturally under the influence of gravity on the substrate surface; dip coating involves immersing the semi-cured adhesive substrate in the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) three times, with each immersion time being 4.5 s.

[0123] Specifically, the Cu2O / TiO2 composite nano-antibacterial coating prepared by the above-described method is applied in medical implant materials, food contact materials, and building exterior wall materials.

[0124] Example 4

[0125] like Figure 1 As shown, a method for preparing a Cu2O / TiO2 composite nano-antibacterial coating includes the following steps:

[0126] (1) Preparation of Cu2O / TiO2 composite nanoparticles: CuSO4·5H2O was dissolved in deionized water, and after stirring and dissolving, P25 particles were added. After stirring evenly, the mixture was quickly poured into a reducing agent and protective agent mixture. The mixture was heated in a water bath at 79.5℃ and stirred at 99r / min. After centrifugation at 1950rpm, ultrasonic cleaning, and drying in a vacuum freeze dryer for 11.9h, Cu2O / TiO2 composite nanoparticles were obtained.

[0127] The preparation method of the reducing agent and protective agent mixed solution is as follows: PVP and C6H8O6 are added to deionized water, stirred and dissolved, and NaOH and H2SO4 are added to adjust the pH value to 11.1; the mass ratio of PVP, C6H8O6 and deionized water is 1:3.98:198; the mass ratio of CuSO4·5H2O and P25 particles is 2.9; ultrasonic cleaning is performed by first ultrasonically cleaning twice with deionized water and then ultrasonically cleaning once with anhydrous ethanol.

[0128] (2) Preparation of hydrophobic modified composite Cu2O / TiO2 particle suspension: PFDTES is added to anhydrous ethanol and magnetically stirred until PFDTES is completely hydrolyzed. The Cu2O / TiO2 composite nanoparticles from step (1) are added and magnetically stirred to mix evenly to obtain hydrophobic modified composite Cu2O / TiO2 particle suspension.

[0129] The mass ratio of PFDTES to Cu2O / TiO2 composite nanoparticles was 0.98:9.9; the magnetic stirring time was 58 min for both.

[0130] (3) Preparation of Cu2O / TiO2 composite nano antibacterial coating: Liquid lithium silicate is evenly dropped onto a clean glass slide using a dropper, and then evenly coated with a silicone brush. After standing and curing for 9.5 min, a semi-cured adhesive substrate is obtained. The hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) is evenly sprayed, dropped, or dipped onto the surface of the semi-cured adhesive substrate, and then dried at room temperature for 23.5 h to obtain the Cu2O / TiO2 composite nano antibacterial coating.

[0131] In step (3), spraying involves uniformly spraying the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) onto the semi-cured adhesive substrate three times at a distance of 21 cm above the substrate using a sprayer; drop coating involves uniformly dropping the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) onto the surface of the semi-cured substrate, gently shaking the substrate during the drop coating process to ensure uniform coating coverage, and allowing the suspension to flow naturally under the influence of gravity on the substrate surface; dip coating involves immersing the semi-cured adhesive substrate in the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) three times, with each immersion time being 3.5 s.

[0132] Specifically, the Cu2O / TiO2 composite nano-antibacterial coating prepared by the above-described method is applied in medical implant materials, food contact materials, and building exterior wall materials.

[0133] Example 5

[0134] like Figure 1 As shown, a method for preparing a Cu2O / TiO2 composite nano-antibacterial coating includes the following steps:

[0135] (1) Preparation of Cu2O / TiO2 composite nanoparticles: CuSO4·5H2O was dissolved in deionized water, and after stirring and dissolving, P25 particles were added. After stirring evenly, the mixture was quickly poured into a solution of reducing agent and protective agent. The mixture was heated in a water bath at 80°C and stirred at 100r / min. After centrifugation at 2000rpm, ultrasonic cleaning, and drying in a vacuum freeze dryer for 12h, Cu2O / TiO2 composite nanoparticles were obtained.

[0136] The preparation method of the reducing agent and protective agent mixed solution is as follows: PVP and C6H8O6 are added to deionized water, stirred and dissolved, and NaOH and H2SO4 are added to adjust the pH value to 11; the mass ratio of PVP, C6H8O6 and deionized water is 1:4:200; the mass ratio of CuSO4·5H2O and P25 particles is 3:7; ultrasonic cleaning is performed by first ultrasonically cleaning twice with deionized water and then ultrasonically cleaning once with anhydrous ethanol.

[0137] (2) Preparation of hydrophobic modified composite Cu2O / TiO2 particle suspension: PFDTES is added to anhydrous ethanol and magnetically stirred until PFDTES is completely hydrolyzed. The Cu2O / TiO2 composite nanoparticles from step (1) are added and magnetically stirred to mix evenly to obtain hydrophobic modified composite Cu2O / TiO2 particle suspension.

[0138] The mass ratio of PFDTES to Cu2O / TiO2 composite nanoparticles was 1:10; the magnetic stirring time was 60 min for both.

[0139] (3) Preparation of Cu2O / TiO2 composite nano antibacterial coating: Liquid lithium silicate is evenly dropped onto a clean glass slide using a dropper, and then evenly coated with a silicone brush. After standing and curing for 10 minutes, a semi-cured adhesive substrate is obtained. The hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) is evenly sprayed, dropped, or dipped onto the surface of the semi-cured adhesive substrate, and then dried at room temperature for 24 hours to obtain the Cu2O / TiO2 composite nano antibacterial coating.

[0140] In step (3), spraying involves spraying the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) onto the semi-cured adhesive substrate three times using a sprayer at a distance of 23 cm above the substrate; drop coating involves uniformly dropping the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) onto the surface of the semi-cured substrate, gently shaking the substrate during the drop coating process to ensure uniform coating coverage, and allowing the suspension to flow naturally under the influence of gravity on the substrate surface; dip coating involves immersing the semi-cured adhesive substrate in the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) three times, with each immersion time being 4 seconds.

[0141] Specifically, the Cu2O / TiO2 composite nano-antibacterial coating prepared by the above-described method is applied in medical implant materials, food contact materials, and building exterior wall materials.

[0142] Example 6

[0143] like Figure 1 As shown, a method for preparing a Cu2O / TiO2 composite nano-antibacterial coating includes the following steps:

[0144] (1) Preparation of Cu2O / TiO2 composite nanoparticles: CuSO4·5H2O was dissolved in deionized water, and after stirring and dissolving, P25 particles were added. After stirring evenly, the mixture was quickly poured into a solution of reducing agent and protective agent. The mixture was heated in a water bath at 80°C and stirred at 101r / min. After centrifugation at 2000rpm, ultrasonic cleaning, and drying in a vacuum freeze dryer for 12.1h, Cu2O / TiO2 composite nanoparticles were obtained.

[0145] The preparation method of the reducing agent and protective agent mixed solution is as follows: PVP and C6H8O6 are added to deionized water, stirred and dissolved, and NaOH and H2SO4 are added to adjust the pH value to 10.9; the mass ratio of PVP, C6H8O6 and deionized water is 1:4.01:201; the mass ratio of CuSO4·5H2O and P25 particles is 3.1:7.05; ultrasonic cleaning is performed by first ultrasonically cleaning twice with deionized water and then ultrasonically cleaning once with anhydrous ethanol.

[0146] (2) Preparation of hydrophobic modified composite Cu2O / TiO2 particle suspension: PFDTES is added to anhydrous ethanol and magnetically stirred until PFDTES is completely hydrolyzed. The Cu2O / TiO2 composite nanoparticles from step (1) are added and magnetically stirred to mix evenly to obtain hydrophobic modified composite Cu2O / TiO2 particle suspension.

[0147] The mass ratio of PFDTES to Cu2O / TiO2 composite nanoparticles was 1.02:10.1; the magnetic stirring time was 55–63 min.

[0148] (3) Preparation of Cu2O / TiO2 composite nano antibacterial coating: Liquid lithium silicate is evenly dropped onto a clean glass slide using a dropper, and then evenly coated with a silicone brush. After standing and curing for 10 minutes, a semi-cured adhesive substrate is obtained. The hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) is evenly sprayed, dropped, or dipped onto the surface of the semi-cured adhesive substrate, and then dried at room temperature for 24 hours to obtain the Cu2O / TiO2 composite nano antibacterial coating.

[0149] In step (3), spraying involves spraying the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) onto the semi-cured adhesive substrate three times using a sprayer at a distance of 23 cm above the substrate; drop coating involves uniformly dropping the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) onto the surface of the semi-cured substrate, gently shaking the substrate during the drop coating process to ensure uniform coating coverage, and allowing the suspension to flow naturally under the influence of gravity on the substrate surface; dip coating involves immersing the semi-cured adhesive substrate in the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) three times, with each immersion time being 4 seconds.

[0150] Specifically, the Cu2O / TiO2 composite nano-antibacterial coating prepared by the above-described method is applied in medical implant materials, food contact materials, and building exterior wall materials.

[0151] Example 7

[0152] like Figure 1 As shown, a method for preparing a Cu2O / TiO2 composite nano-antibacterial coating includes the following steps:

[0153] (1) Preparation of CuSO4-P25 mixed suspension: Weigh 1g CuSO4·5H2O and dissolve it in 100mL of deionized water. After stirring and dissolving, add P25 particles according to the mass ratio of CuSO4·5H2O to P25 particles. The mass ratio of CuSO4·5H2O to P25 particles is 3:7 to obtain CuSO4-P25 mixed suspension.

[0154] (2) Preparation of reducing agent and protective agent mixed solution: Weigh 0.5g PVP and 2g C6H8O6 into 100mL deionized water, stir at 100r / min to dissolve them, add NaOH and H2SO4 to adjust the pH value to 11.1, and obtain the reducing agent and protective agent mixed solution;

[0155] (3) Preparation of Cu2O / TiO2 composite nanoparticles: The reducing agent and protective agent mixture solution in step (2) was heated to 80°C in a water bath, and then the CuSO4-P25 mixed suspension in step (1) was added to allow the two to react fully. The reaction time was 60 min, the reaction temperature was 80°C, the stirring speed was 100 r / min, the mixture was centrifuged at 2000 rpm, ultrasonically cleaned twice with deionized water, ultrasonically cleaned once with anhydrous ethanol, and dried in a vacuum freeze dryer for 12 h to obtain Cu2O / TiO2 composite nanoparticles.

[0156] (4) Preparation of hydrophobic modified composite Cu2O / TiO2 particle suspension: Accurately add 150 μL of PFDTES to anhydrous ethanol, stir the mixture magnetically for 1 h to ensure complete hydrolysis of PFDTES, then add 1.5 g of Cu2O / TiO2 composite nanoparticles from step (4) to the mixture, and stir again on a magnetic stirrer for 1 h to obtain hydrophobic modified composite Cu2O / TiO2 particle suspension;

[0157] (5) Preparation of Cu2O / TiO2 composite nano antibacterial coating: Liquid lithium silicate was evenly dropped onto a clean glass slide using a dropper, and then spread evenly with a silicone brush. The mixture was allowed to stand and cure for 10 minutes. The hydrophobic modified Cu2O / TiO2 composite coating was prepared by spraying. At a distance of 20-25 cm above the substrate, a suspension of dual-scale hydrophobic modified Cu2O / TiO2 particles was evenly sprayed three times onto the semi-cured adhesive substrate. The mixture was then dried at room temperature for 24 hours to obtain the Cu2O / TiO2 composite nano antibacterial coating.

[0158] Specifically, the Cu2O / TiO2 composite nano-antibacterial coating prepared by the above-described method is applied in medical implant materials, food contact materials, and building exterior wall materials.

[0159] The Cu2O / TiO2 composite nano-antibacterial coating prepared in this embodiment was used as sample CT37 in the sieve performance test of this application.

[0160] Product performance related experiments

[0161] 1. Hydrophobic modification of Cu2O / TiO2 composite nanoparticles

[0162] As shown in Table 2, different amounts of PFDTES were accurately added to anhydrous ethanol, and the mixture was magnetically stirred for 55–63 min to ensure complete hydrolysis of PFDTES. Next, 1.5 g of Cu2O / TiO2 composite nanoparticles were added to the mixture, and it was stirred again on a magnetic stirrer for 55–63 min to obtain a hydrophobically modified composite Cu2O / TiO2 particle suspension.

[0163] Table 2. Amount of hydrophobic modifier added

[0164] Sample number 1 2 3 4 5 6 Modifier addition amount (μL) 0 50 100 150 200 250

[0165] 2. Introduction of dual-scale Cu2O / TiO2 composite nano-antibacterial coating

[0166] The Cu2O / TiO2 suspension was sprayed onto the substrate coated with the adhesive using a sprayer, and all coated samples were left to dry and cure at room temperature for 23–25 hours.

[0167] As shown in Table 3, the experimental samples with different Cu2O / TiO2 mass ratios (0:10, 2:8, 3:7, 4:6, 10:0) are designated as CT010, CT28, CT37, CT46, and CT100, respectively. Coatings were prepared on different substrates, including wood chips, zinc sheets, and stainless steel, using the same method. Sample CT37 is a Cu2O / TiO2 composite nano-antibacterial coating prepared by the method in Example 7 of this application.

[0168] Table 3 Nomenclature of coatings prepared with different Cu2O / TiO2 mass ratios

[0169] Sample Name <![CDATA[Mass ratio of Cu2O / TiO2]]> CT010 0:10 CT28 2:8 CT37 3:7 CT46 4:6 CT100 10:0

[0170] The amounts of hydrophobic modifiers added in the following experiments are shown in Table 2, and the naming of coatings prepared with different Cu2O / TiO2 mass ratios is shown in Table 3.

[0171] Experimental Example 1

[0172] Antibacterial experiment of Cu2O / TiO2 composite nano-antibacterial coating

[0173] The sterilization experiment of the Cu2O / TiO2 coating was conducted in a sterile operating table. The experimental materials were steam sterilized using an autoclave (Hirayama HVE50). The 24-well plates were irradiated with ultraviolet light to ensure sterility. The bacterial solution was diluted with physiological saline and then... 8 A suitable amount of bacterial solution was added to each well at a concentration of CFU / mL, ensuring complete coverage of the sample surface. A 1cm × 1cm composite coating was then added to each well of the 24-well plate. The plate was then placed in a natural environment and exposed to natural light for long-term natural light photocatalytic sterilization experiments. The experiment was conducted in Nanning, Guangxi Province, from May to July, under ambient temperatures of 26–32℃ and a light intensity of 132.34 kW / m². 2 .

[0174] Experimental results are as follows Figure 2 , Figure 3 , Figure 4 , Figure 5 As shown, after the experiment, the bacterial suspension was continuously diluted 10-fold with sterile physiological saline, and the diluted bacterial suspension was evenly spread on the culture medium and incubated at 37°C for 18 hours. After incubation, the culture medium was photographed and the number of colonies was recorded. Meanwhile, untreated Escherichia coli and Staphylococcus aureus bacterial suspensions were set up as control groups for comparative analysis.

[0175] The antibacterial properties of the coating were tested according to the national standard GB / T 21866—2008. The plate count standard was based on standard GB4789.2—2016, and the antibacterial rate R was calculated using the following formula:

[0176]

[0177] In the formula, B and C are the average colony counts of the control group and the experimental group, respectively.

[0178] Experiment Example 2

[0179] Bacterial adhesion test of Cu2O / TiO2 composite nano-antibacterial coating

[0180] Before the experiment, the coated samples were autoclaved to eliminate any potential interference from other microorganisms. Coated samples measuring 1cm × 1cm were placed in 24-well plates, each well containing 1mL of bacterial suspension composed of Staphylococcus aureus (concentration 10). 8 The sample consisted of either CFU / mL or E. coli (concentration 10⁸ CFU / mL) and physiological saline. The sample and bacterial suspension were co-cultured at a constant temperature of 37°C in the dark for 2 hours.

[0181] Gently rinse the coating with sterile saline solution to remove bacteria not adhering to the sample surface, ensuring that the bacterial count measured later represents only the bacteria actually adhering to the sample. Place the rinsed coating into a brand new sterile plate, add 1 mL of sterile saline solution, and sonicate the coating for 3 min to detach the bacteria from the sample surface and suspend them in the saline solution. Pipette 100 μL of the sonicated saline solution and inoculate this 100 μL bacterial suspension onto LB solid agar medium and incubate at 37°C for 18 h. After incubation, count the colonies on the LB solid agar. The experimental results are as follows: Figure 6 , Figure 7 , Figure 8 As shown.

[0182] Experimental Example 3

[0183] Comparison of antibacterial properties

[0184] Although superhydrophobic coatings perform well in resisting bacterial adhesion, traditional superhydrophobic coatings, lacking bactericidal capabilities, cannot resist bacterial adhesion over long-term use. Once these bacteria successfully attach and form cell membranes, the superhydrophobic coating becomes contaminated and gradually loses its original properties. A composite coating prepared by introducing the inorganic antibacterial agent Cu2O into TiO2 using an impregnation-in-situ chemical method can effectively inhibit bacterial adhesion and reproduction in practical use. This is achieved by rinsing the superhydrophobic coating with deionized water to remove surface-adhered bacteria, while the copper ions released by the Cu2O / TiO2 coating in the early stages of use also effectively inhibit bacterial adhesion and reproduction.

[0185] The antibacterial properties of coatings prepared by existing technologies such as electron beam powder bed melting, DC reactive magnetron sputtering, hydrothermal method, mechanochemical method, sol-gel method and in-situ chemical reduction method of Example 5 of this application were compared. The experimental results are shown in Table 4.

[0186] Table 4 Comparison of antibacterial properties of Cu2O / CuO / Cu-TiO2 composite coatings

[0187]

[0188]

[0189] Experiment Example 4

[0190] Mechanical stability of Cu2O / TiO2 composite nano-antibacterial coating

[0191] Improving durability is one of the key issues that superhydrophobic coatings must address in practical applications. To accurately evaluate the wear resistance of the coating, the friction process of the composite coating in actual use was simulated. The coating was subjected to multiple friction cycles, and the contact angle and roll-off angle of the coating after wear were measured. The changes in angle before and after friction were compared to evaluate the mechanical durability of the coating during friction cycles.

[0192] Figure 14 The results of the wear resistance test on the Cu2O / TiO2 composite nano-antibacterial coating sample CT37 prepared in Example 7 are as follows: After 100 cycles of friction, the contact angle of the coating gradually decreased from 152.3° to 96.3°, and the roll-off angle gradually increased from 9.7° to 64.3°. This is attributed to the chemical bonding between the lithium silicate binder and the composite coating, as well as the spraying preparation method. During the preparation process, some nanoparticles were embedded in the substrate binder, and the coating still maintained a certain degree of hydrophobicity after multiple wear cycles. After 10 cycles of friction testing, the coating's contact angle (CA) was greater than 150° and the roll-off angle (SA) was less than 10°, demonstrating good self-cleaning properties.

[0193] When the wear cycle reaches 100 times or more, the hydrophobicity of the coating decreases significantly. The main reason is that a large number of nanoparticles on the surface of the composite nano antibacterial coating are stripped and lost during the wear cycle. The originally rough coating surface gradually becomes smooth as the underlying substrate material is exposed. This change directly leads to a sharp decrease in the contact angle of the coating, and the superhydrophobicity of the coating is severely damaged during the wear process.

[0194] The composite coating retained some hydrophobic properties after 100 wear cycles, indicating that even after severe wear, the coating surface can still maintain a certain rough hydrophobic structure, thus retaining some anti-adhesion and self-cleaning properties. The cyclic wear test results demonstrate the coating's excellent mechanical stability, laying the foundation for further research on its performance. The experimental results are shown in Table 5 below.

[0195] Table 5 Comparison of wear resistance of coatings prepared with different adhesives

[0196] Serial Number coating adhesives Curing conditions Load weight / wear cycle References 1 <![CDATA[POPG-Cu 2+ ]]> PDMS 120℃ 200g / 50 servings <![CDATA[Li

[103] ]]> 2 <![CDATA[SiO2 / SiPU]]> Si / TPU 80℃ 200g / 30 servings <![CDATA[Gou

[104] ]]> 3 <![CDATA[SiO2-EP]]> Epoxy resin room temperature 100g / 150 times <![CDATA[Feng

[105] ]]> 4 <![CDATA[Cu2O / TiO2]]> Lithium silicate room temperature 200g / 120 times Example 7

[0197] Table 5 compares the wear resistance of different coatings in the literature. It can be seen that coatings prepared using lithium silicate as a binder exhibit better wear resistance than most coatings prepared using other binders such as PDMS, epoxy resin, and Si / TPU. Using lithium silicate as a binder not only improves the mechanical stability of the coating but also allows it to cure at room temperature, reducing reaction energy consumption. In summary, introducing lithium silicate as a binder significantly improves the durability of composite coatings and simplifies the coating preparation process.

[0198] Experimental Example 5

[0199] Chemical stability of Cu2O / TiO2 composite nano-antibacterial coating

[0200] Superhydrophobic coatings, in practical applications, must possess the ability to resist corrosion from media with varying pH levels to ensure they maintain their unique superhydrophobic properties even after long-term exposure to such environments. In-depth research on the stability of superhydrophobic coatings in extreme chemical environments is crucial for expanding their application areas and enhancing their practical value. This study assesses chemical stability by measuring changes in contact angle and roll-off angle after placing the coating in air, immersing it in solutions of different pH values, and immersing it in a physiological saline buffer solution simulating bacterial growth environments for a period of time.

[0201] Figure 15 The image shows the changes in contact angle and roll-off angle of the Cu2O / TiO2 composite nano antibacterial coating sample CT37 prepared in Example 7 in air. After being placed in air for 28 days, the composite coating was not corroded by water vapor, oxygen and other gases in the air, showing good chemical stability. The coating still has superhydrophobic properties. The contact angle measured on the surface of the coating is still maintained at 151°, and its roll-off angle remains below 10°.

[0202] Figure 16 The image shows the change in the contact angle of the Cu2O / TiO2 composite nano-antibacterial coating sample CT37 prepared in Example 7 after immersion in solutions with different pH values. Figure 17The image shows the roll angle changes of the Cu2O / TiO2 composite nano-antibacterial coating sample CT37 prepared in Example 7 after immersion in solutions of different pH values. In the initial immersion period (within 5 days), the composite coating maintained its superhydrophobic state, with a hydrophobic angle greater than 150°. This indicates that the coating possesses a certain degree of resistance to strong acid and alkali solutions for a certain period. However, this resistance gradually weakens over time, leading to a decrease in the coating's hydrophobic properties. The excellent corrosion resistance of the composite coating to strong acid and alkali solutions is mainly attributed to its rough, layered micro / nano structure. After immersion in the solution, the layered structure traps air, forming a barrier that effectively prevents the coating from being wetted and corroded by the strong acid and alkali solutions.

[0203] However, the corrosion resistance brought by the rough structure gradually decreases with the extension of immersion time. After immersion in strong acids and alkalis for 28 days, the hydrophobic angle of the coating drops to below 150° and no longer has superhydrophobic properties. Although the contact angle of the coating decreases after long-term immersion, its hydrophobic angle is still greater than 90° and it still maintains a certain degree of hydrophobicity.

[0204] The 28-day acid and alkali solution immersion experiment showed that the composite coating immersed in pH=11 solution showed the largest decrease in hydrophobic angle, from 155.3° to 130.5°. The decrease in hydrophobic angle was smallest in acidic to neutral solutions of pH=5 and pH=7. Strong alkaline solutions were more corrosive to the composite coating than strong acid solutions. This may be because the strong alkaline solution reacts with the fluorinated hydrophobic groups on the coating surface, resulting in a more significant decrease in the hydrophobic properties of the coating.

[0205] In addition, to more accurately simulate the actual environment in which bacteria exist, the test medium was replaced with physiological saline solution instead of acid and alkaline solution, and a 28-day immersion experiment was conducted under the same experimental conditions. The chemical corrosion resistance of the composite coating in actual sterilization applications was evaluated by measuring the changes in the rolling angle and sliding angle of the composite coating at regular intervals.

[0206] Figure 18 The graph shows the changes in contact angle and roll-off angle of the Cu2O / TiO2 composite nano antibacterial coating sample CT37 prepared in Example 7 after immersion in physiological saline. As can be seen from the graph, after 28 days of immersion, the composite coating still has good superhydrophobic properties, and the hydrophobic angle is still maintained above 150°. However, the roll-off angle increases from below 10° to about 15°.

[0207] Experimental results show that the Cu2O / TiO2 composite nano-antibacterial coating prepared in this application has good chemical corrosion resistance and has the potential to resist acid and alkali solution corrosion for long-term service in practical applications.

[0208] Experimental Example 6

[0209] Resistance to natural light aging of Cu2O / TiO2 composite nano-antibacterial coating

[0210] In practical applications, composite coatings exposed to natural light for extended periods inevitably suffer from photoaging damage, resulting in yellowing, cracking, and peeling of the coating surface, ultimately leading to a decrease in coating performance. Therefore, in-depth research into the coating's resistance to natural light aging is particularly important.

[0211] like Figure 19 As shown, after 3 days of natural light exposure aging, the hydrophobic angle of the antibacterial coating exceeded 150° and the roll-off angle was less than 10°. After 16 days under the same environmental conditions, the hydrophobic angle decreased to 91.2°, yet it still maintained its hydrophobic state. The experimental results demonstrate that the hydrophobic properties of the antibacterial coating remained stable during the 16-day natural sunlight aging process. Natural light excites the Cu2O / TiO2 composite nanoparticles to generate active substances that degrade low surface energy polymers on the coating surface, leading to a decrease in the hydrophobic angle.

[0212] The change in the content of long carbon-fluorine chains with low surface energy on the coating surface was investigated by EDS analysis of the fluorine (F) element content after natural light aging. After 3 days of natural light exposure, the content of F in the coating was analyzed. Figure 20 The results showed that the F element content on the coating surface dropped to 2.23% at this time. The coating was still in a superhydrophobic state. The study showed that when the area of ​​low surface energy group modification on the coating surface reaches a certain threshold, the coating as a whole can achieve a superhydrophobic state. After 16 days of natural light irradiation, the F element content of the coating decreased to 0.21%, the contact angle of the coating was less than 150°, and it lost its superhydrophobic properties.

[0213] When the area modified by hydrophobic groups on the coating exceeds a predetermined threshold, the chemical and physical structure of the coating surface changes, resulting in a significant reduction in the contact angle of droplets on the coating surface. This no longer meets the standard requirements for superhydrophobic coatings, and the coating loses the advantages brought by superhydrophobic properties such as self-cleaning and corrosion resistance.

[0214] Experimental Example 7

[0215] The hydrophobic and self-cleaning properties of the Cu2O / TiO2 composite nano-antibacterial coating

[0216] The coating exhibits excellent self-cleaning properties, demonstrating its ability to maintain surface cleanliness over a long period and reduce maintenance costs. This self-cleaning performance is primarily attributed to the unique surface properties of the superhydrophobic coating, with a contact angle greater than 150° and a roll-off angle less than 10°. This makes it difficult for liquids (such as rainwater) to spread on the surface, forming easily rolling droplets. The extremely small roll-off angle allows contaminants (such as dust particles) on the coating surface to be easily carried away by the droplets, achieving a self-cleaning effect. The wide applicability of the Cu2O / TiO2 composite nano-antibacterial coating prepared in Example 7 of this application was investigated by spraying it onto different substrates, including glass slides, wood chips, stainless steel, and zinc sheets. The surface self-cleaning properties of the coating prepared on different substrates were also tested.

[0217] Experimental results are as follows Figure 21 As shown, water droplets spread out on the uncoated substrate and do not easily roll off when tilted. Coatings prepared by spraying onto various substrates such as glass, wood, and metal exhibit a superhydrophobic state; water droplets easily roll off when tilted, and the coating surface is flat and uniform with no obvious powdering. This indicates that the Cu2O / TiO2 composite nano-antibacterial coating prepared in this application possesses excellent hydrophobic properties, expanding the practical application range of the coating.

[0218] The self-cleaning effect of the composite coating was observed by uniformly spreading fly ash on the coating surfaces of different substrates such as glass slides, wood chips, stainless steel, and zinc sheets, followed by dripping water onto the surface. Figure 22 As demonstrated, when liquid droplets fall onto the coating surface, they roll off rapidly, carrying fly ash with them, thus cleaning the coating surface. Superhydrophobic coatings prepared on different substrates all exhibit good self-cleaning properties.

[0219] Thanks to the dual-scale rough nanostructure formed by Cu2O / TiO2, the coating surface roughness is significantly increased, and the coating has the ability to trap air on the surface to form an air cushion, reducing the contact area for droplets. In the self-cleaning experiment, fly ash particles on the coating surface can easily roll off with water droplets without leaving any traces on the coating surface. This series of phenomena fully demonstrates that the composite coating can effectively solve the problem of contaminant accumulation on the surface affecting subsequent performance in long-term practical applications, quickly restore the superhydrophobic properties of the coating, and ensure that the coating maintains excellent superhydrophobic self-cleaning performance during long-term use.

[0220] The antibacterial coating obtained in this application has the characteristics of self-cleaning, high durability and broad-spectrum antibacterial properties, which can effectively reduce the risk of infection by drug-resistant bacteria and is suitable for medical implants, food contact materials, building exterior wall materials and other scenarios.

[0221] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a Cu2O / TiO2 composite nano-antibacterial coating, characterized in that, Includes the following steps: (1) Preparation of Cu2O / TiO2 composite nanoparticles: CuSO4·5H2O was dissolved in deionized water, and after stirring and dissolving, P25 particles were added. After stirring evenly, the mixture was quickly poured into a solution of reducing agent and protective agent. The mixture was heated and stirred in a water bath, and then centrifuged, ultrasonically cleaned and dried to obtain Cu2O / TiO2 composite nanoparticles. (2) Preparation of hydrophobic modified composite Cu2O / TiO2 particle suspension: PFDTES is added to anhydrous ethanol and magnetically stirred until PFDTES is completely hydrolyzed. The Cu2O / TiO2 composite nanoparticles from step (1) are added and magnetically stirred to mix evenly to obtain hydrophobic modified composite Cu2O / TiO2 particle suspension. (3) Preparation of Cu2O / TiO2 composite nano antibacterial coating: Liquid lithium silicate is evenly dropped onto a clean glass slide using a dropper, and then evenly coated with a silicone brush. After standing and curing, a semi-cured adhesive substrate is obtained. The hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) is evenly sprayed, dropped, or dipped onto the surface of the semi-cured adhesive substrate, and then dried at room temperature to obtain the Cu2O / TiO2 composite nano antibacterial coating.

2. The method for preparing a Cu2O / TiO2 composite nano-antibacterial coating according to claim 1, characterized in that: In step (1), the preparation method of the reducing agent and protective agent mixed solution is as follows: PVP and C6H8O6 are added to deionized water, stirred and dissolved, and NaOH and H2SO4 are added to adjust the pH value to 10.8-11.2; The mass ratio of PVP, C6H8O6 and deionized water is 1:(3.95~4.05):(195~205).

3. The method for preparing a Cu2O / TiO2 composite nano-antibacterial coating according to claim 1, characterized in that: In step (1), the mass ratio of CuSO4·5H2O to P25 particles is (2.8-3.3):(6.6-7.3).

4. The method for preparing a Cu2O / TiO2 composite nano-antibacterial coating according to claim 1, characterized in that: In step (1), the temperature of the water bath heating and stirring dissolution is 79-81°C, and the stirring speed is 98-105 r / min.

5. The method for preparing a Cu2O / TiO2 composite nano-antibacterial coating according to claim 1, characterized in that: In step (1), the centrifuge speed during centrifugal separation is 1900-2100 rpm.

6. The method for preparing a Cu2O / TiO2 composite nano-antibacterial coating according to claim 1, characterized in that: In step (1), the ultrasonic cleaning is performed by first ultrasonically cleaning twice with deionized water and then ultrasonically cleaning once with anhydrous ethanol; the drying is performed in a vacuum freeze dryer for 11.7 to 12.5 hours.

7. The method for preparing a Cu2O / TiO2 composite nano-antibacterial coating according to claim 1, characterized in that: In step (2), the mass ratio of PFDTES and Cu2O / TiO2 composite nanoparticles is (0.95-1.1):(9.8-10.3); the magnetic stirring time is 55-63 min.

8. The method for preparing a Cu2O / TiO2 composite nano-antibacterial coating according to claim 1, characterized in that: In step (3), the static curing time is 9 to 11 minutes; the room temperature drying time is 23 to 25 hours.

9. The method for preparing a Cu2O / TiO2 composite nano-antibacterial coating according to claim 1, characterized in that: In step (3), the spraying is to uniformly spray the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) onto the semi-cured adhesive substrate three times at a distance of 20-25 cm above the semi-cured adhesive substrate using a sprayer. The drop coating is a process of uniformly drop coating the hydrophobic modified composite Cu2O / TiO2 particle suspension from step (2) onto the surface of a semi-cured substrate. During the drop coating process, the substrate is slightly shaken to ensure uniform coating coverage. The suspension flows naturally and levels under the gravity of the substrate surface. The dip coating involves immersing the semi-cured adhesive substrate in the hydrophobic modified composite Cu2O / TiO2 particle suspension of step (2) three times, with each immersion time being 3 to 5 seconds.

10. The application of the Cu2O / TiO2 composite nano-antibacterial coating prepared by the method of preparation of Cu2O / TiO2 composite nano-antibacterial coating according to claim 1 in medical implant materials, food contact materials, and building exterior wall materials.

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