Hydrophobic antibacterial particles, a method for preparing the same and use thereof in a stone-like paint

Abstract

This invention discloses a hydrophobic antibacterial particle, its preparation method, and its application in stone paint. The hydrophobic antibacterial particle is prepared by first compounding a polylysine-modified polyurea emulsion with a sodium alginate-gelatin solution to obtain a composite emulsion, then encapsulating the composite emulsion with Artemisia argyi-coupled modified zinc oxide nanoparticles to form spherical particles, and finally reacting these spherical particles with calcium chloride via a crosslinking reaction. The Artemisia argyi-coupled modified zinc oxide nanoparticles are obtained by sequentially modifying zinc oxide with Artemisia argyi extract and a silane coupling agent. The hydrophobic antibacterial particle provided by this invention exhibits excellent antibacterial properties, hydrophobicity, and antibacterial durability. Adding the hydrophobic antibacterial particle to stone paint results in a stone paint containing the hydrophobic antibacterial particle that not only possesses excellent antibacterial properties, hydrophobicity, and antibacterial durability, but also has low requirements for ambient light, exhibiting good antibacterial performance in both visible light and dark environments.

Description

Technical Field

[0001] This invention relates to a hydrophobic antibacterial particle, its preparation method, and its application in stone-like paint, belonging to the field of functional coatings technology. Background Technology

[0002] Stone-like paint is a type of coating that closely resembles the decorative effect of marble and granite. It is mainly made from natural stone powder of various colors. Buildings decorated with stone-like paint have a natural and realistic color, giving people an elegant, harmonious, and dignified aesthetic, and are suitable for interior and exterior decoration of various types of buildings.

[0003] With the development of coating functionality, especially given the increasing focus on antibacterial coatings due to bacterial infections, densely populated public places are high-risk areas for cross-infection of bacteria. The growth and reproduction of bacteria on building surfaces is a source of illness. The erosion and damage of coating surfaces by microorganisms, leading to shortened material lifespan and potential safety hazards, remains a potential threat to our daily lives. Therefore, the requirements for the antibacterial properties of stone-like paints are becoming increasingly stringent.

[0004] Currently, antibacterial coatings mainly achieve their antibacterial function by adding antibacterial agents. Antibacterial agents in coatings are mainly divided into organic and inorganic antibacterial agents. Among them, organic antibacterial agents are easily decomposed, some are harmful to the environment, and have poor durability.

[0005] Inorganic antibacterial agents are mainly divided into two categories: one is a metal ion-type antibacterial agent that loads metal ions with antibacterial properties, such as silver ions, copper ions, and zinc ions, onto an inorganic carrier; the other is a photocatalytic inorganic antibacterial agent that uses semiconductor materials such as titanium dioxide as the main component and achieves antibacterial activity through their photocatalytic activity. While the former has a significant antibacterial effect on surfaces, its durability is poor. The latter requires higher light exposure and specific environmental conditions to exhibit good bactericidal ability. Therefore, when added to coatings, neither type of coating adequately meets the antibacterial requirements.

[0006] Nano zinc oxide is an n-type semiconductor material, mainly comprising several structures such as hexagonal wurtzite, zinc sphalerite, cesium chloride, and salt rock. Nano zinc oxide is a non-toxic, biocompatible material widely used in the cosmetics, textile, drug delivery, pharmaceutical, and biomedical industries.

[0007] In addition to its UV resistance, nano zinc oxide also has the ability to inhibit bacterial growth and is currently often used as an antibacterial filler in the preparation of antibacterial coatings. For example, in the literature (Preparation of Nano Zinc Oxide / Styrene-Acrylic Emulsion Interior Wall Coating, Journal of Hanshan Normal University, Cai Hong and Qiu Heyuan, Vol. 27, No. 6), nano zinc oxide was added to styrene-acrylic emulsion coating to prepare an antibacterial interior wall coating.

[0008] Although nano zinc oxide has excellent properties, it still has certain drawbacks when applied to antibacterial coatings: 1) While nano zinc oxide has the ability to inhibit bacterial growth, its antibacterial properties and durability are not strong enough to meet the high demand for antibacterial coatings; 2) Generally, if the coating surface is hydrophobic, it can effectively prevent the adhesion of microorganisms, thus giving the coating antibacterial properties. However, current nano zinc oxide is not only prone to agglomeration and has poor compatibility with polymer resins in coatings, but it also cannot be uniformly dispersed in the resin. Furthermore, its hydrophobicity is not good, and when added to coatings, it cannot make the coating surface have good hydrophobic properties, affecting the antibacterial properties of the coating; 3) Like nano titanium dioxide, nano zinc oxide is highly sensitive to ambient light and can only activate active oxygen for antibacterial activity under ultraviolet conditions, which affects the antibacterial properties of the coating.

[0009] To address the aforementioned shortcomings, researchers employed a series of physicochemical methods to modify and enhance nano-zinc oxide, enabling its better application in coatings. For example, the literature (Research on Antibacterial Modification of Nano-Zinc Oxide Particles and Their Application in UV-Curable Coatings, Beijing University of Chemical Technology, Tang Nannan) used silane coupling agents to modify tetragonal needle-shaped and rod-shaped nano-zinc oxide particles, respectively, and used the modified nano-zinc oxide as an additive in the preparation of UV-curable antibacterial coatings; the literature (Research on Triazole Cyclic Fluorinated Aromatic Hydrocarbon Modification of Nano-Zinc Oxide and Its Application in Marine Antifouling Coatings, Hainan University, Yang Yu) used triazole cyclic fluorinated aromatic hydrocarbons to modify nano-zinc oxide, and used the modified nano-zinc oxide as... As an additive, it is used to prepare marine antifouling coatings; in the literature (Green synthesis of nano zinc oxide from Sophora japonica extract and its antibacterial activity, New Chemical Materials, Cheng Zhong, Tang Shanwen, Wu Yu, Wang Juan, Vol. 50, No. 11), Sophora japonica extract is used to modify nano zinc oxide, and the antibacterial activity of the modified nano zinc oxide is tested; in patent CN200910198971.0, zinc oxide modifying agent is used to modify nano zinc oxide particles, and the modified nano zinc oxide is used as a filler to prepare nano zinc oxide antibacterial and antifouling coatings.

[0010] Currently available methods for modifying nano-zinc oxide can modify nano-zinc oxide, but they can only modify one aspect of its properties, such as antibacterial and hydrophobic properties. They cannot simultaneously modify all aspects of nano-zinc oxide, including its antibacterial, hydrophobic, and durability properties. When modified nano-zinc oxide is used as a filler to prepare functional coatings (including functional stone paint), the resulting coatings cannot adequately meet the functional requirements. Summary of the Invention

[0011] To address the aforementioned problems in the existing technology, the purpose of this invention is to provide a hydrophobic antibacterial particle, its preparation method, and its application in stone paint.

[0012] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows:

[0013] A hydrophobic antibacterial particle is prepared by first compounding a polylysine-modified polyurea emulsion with a sodium alginate-gelatin solution to obtain a composite emulsion, then encapsulating the composite emulsion with Artemisia argyi-coupled modified nano zinc oxide to form spherical particles, and then reacting the spherical particles with calcium chloride for crosslinking. The Artemisia argyi-coupled modified nano zinc oxide is obtained by sequentially modifying zinc oxide with Artemisia argyi extract and a silane coupling agent.

[0014] A method for preparing the hydrophobic antibacterial particles of the present invention includes the following steps:

[0015] a) First, dissolve zinc acetate dihydrate in deionized water, then add ammonia and Artemisia argyi extract dropwise. After the addition is complete, stir the mixture at room temperature for 3 to 5 hours (stirring speed is 250 to 500 rpm), collect the solid product, and obtain Artemisia argyi modified nano zinc oxide.

[0016] b) Artemisia argyi modified nano zinc oxide was dispersed in ethanol, and then a silane coupling agent and deionized water were added to it. The resulting mixture was stirred at 75 to 85°C for 1 to 3 hours (stirring speed of 300 to 500 rpm). The solid product was collected to obtain Artemisia argyi-coupled modified nano zinc oxide.

[0017] c) Isocyanate was added to the reactor, and polyetheramine was added dropwise at 40-45°C. After the addition was complete, the mixture was kept at this temperature and stirred for 2-2.5 hours (stirring speed 180-220 rpm). Then, the temperature was raised to 80-85°C, and a hydrophilic chain extender was added. After the addition was complete, the mixture was kept at this temperature and stirred for 1-1.5 hours. Next, the temperature was kept constant at 80-85°C, and polylysine was added. After the addition was complete, the mixture was kept at this temperature and stirred for 1-1.5 hours. Then, the temperature was lowered to 70-75°C, and a crosslinking agent was added. After the addition was complete, the mixture was kept at this temperature and stirred for 0.5-1 hour. The temperature was further lowered to 45-50°C, and a neutralizing agent was added. After the addition was complete, the mixture was kept at this temperature and stirred for 15-30 minutes. Finally, the temperature was lowered to 30-35°C, and deionized water was added dropwise. After the addition was complete, the mixture was kept at this temperature and stirred for 0.5-1.5 hours (stirring speed 450-700 rpm) to obtain a polylysine-modified polyurea emulsion.

[0018] d) Add equal masses of sodium alginate and gelatin to deionized water. After the addition is complete, keep warm and stir at 60-70℃ for 5-6 hours to obtain sodium alginate-gelatin solution.

[0019] e) Mix the polylysine-modified polyurea emulsion from step c) with the sodium alginate-gelatin solution from step d) at room temperature to obtain a composite emulsion.

[0020] f) The composite emulsion is uniformly added to the surface of Artemisia argyi-coupled modified nano zinc oxide, and shaken evenly to coat the composite emulsion with Artemisia argyi-coupled modified nano zinc oxide, forming spherical particles. The spherical particles are added to a calcium chloride aqueous solution, and the resulting mixture is subjected to a cross-linking reaction at room temperature for 1 to 3 hours. The reaction is then stopped, and the resulting reactant is freeze-dried under vacuum to a constant weight (freezing temperature of -20 to -40°C, freezing time of 24 to 72 hours) to obtain the hydrophobic antibacterial particles.

[0021] In one embodiment, step a) of preparing the Artemisia argyi extract includes the following operations:

[0022] The dried mugwort was soaked in a 60-70 wt% ethanol aqueous solution at a temperature of 60-70℃ for 30-60 minutes. After soaking, the solution was filtered, and the resulting filtrate was the mugwort extract.

[0023] In a preferred embodiment, during the preparation of the Artemisia argyi extract, the amounts of dried Artemisia argyi and 60-70 wt% ethanol aqueous solution added are: 5-10 parts by weight of dried Artemisia argyi and 40-90 parts by weight of 60-70 wt% ethanol aqueous solution.

[0024] In one embodiment, in step a), the amounts of zinc acetate dihydrate, deionized water, ammonia, and Artemisia argyi extract added are: 4-9 parts by weight of zinc acetate dihydrate, 20-40 parts by weight of deionized water, 2-5 parts by weight of ammonia, and 1-10 parts by weight of Artemisia argyi extract.

[0025] In one implementation scheme, step a) involves collecting the solid product as follows:

[0026] After the reaction was completed, the reaction solution was vacuum filtered, and the resulting filter cake was washed with anhydrous ethanol and deionized water, and then dried at 80 to 125°C for 7 to 12 hours to obtain the modified Artemisia argyi nano zinc oxide.

[0027] In one embodiment, in step b), the silane coupling agent is any one of KH570, KH550, and KH560.

[0028] In one embodiment, in step b), the amounts of modified nano zinc oxide, ethanol, silane coupling agent, and deionized water added are: 1-2 parts by weight of modified nano zinc oxide, 30-60 parts by weight of ethanol, 5-20 parts by weight of silane coupling agent, and 10-20 parts by weight of deionized water.

[0029] In one implementation scheme, step b) involves collecting the solid product as follows:

[0030] After the reaction was completed, the reaction solution was cooled to room temperature and centrifuged. The precipitate was washed with ethanol and filtered. The filtered product was dried at 70-80°C for 8-12 hours to obtain the Artemisia argyi-coupled modified nano zinc oxide.

[0031] In one embodiment, in step c), the amounts of isocyanate, polyetheramine, hydrophilic chain extender, polylysine, crosslinking agent, neutralizing agent, and deionized water added are as follows: 3.5 to 7 parts by weight of isocyanate, 10.5 to 21 parts by weight of polyetheramine, 0.28 to 0.56 parts by weight of hydrophilic chain extender, 0.1 to 0.28 parts by weight of polylysine, 0.14 to 0.28 parts by weight of crosslinking agent, 0.38 to 0.4 parts by weight of neutralizing agent, and 20 to 40 parts by weight of deionized water.

[0032] In one embodiment, in step c), the isocyanate is any one of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, polymethylene polyphenyl polyisocyanate, and hexamethylene diisocyanate; the polyetheramine is any one of polyetheramine D2000, polyetheramine ED900, and polyetheramine D230; the hydrophilic chain extender is any one of 2,2-bis(hydroxymethyl)butyric acid, dimethylolpropionic acid, and dihydroxysulfonate; the polylysine is any one of ε-polylysine and α-polylysine; the crosslinking agent is any one of trimethylolpropane, 1,2-propylene glycol, and ethylene glycol; and the neutralizing agent is any one of triethylamine, dimethylethanolamine, and ammonia.

[0033] In one embodiment, in step d), the mass concentration of the obtained sodium alginate-gelatin solution is 2% to 6%.

[0034] In one embodiment, in step e), the amount of polylysine-modified polyurea emulsion and sodium alginate-gelatin solution added to the composite emulsion is: 0.09 to 0.12 parts by weight of polylysine-modified polyurea emulsion and 15 to 20 parts by weight of sodium alginate-gelatin solution.

[0035] In one embodiment, in step f), the amount of Artemisia argyi-coupled modified nano zinc oxide and calcium chloride aqueous solution added is: 0.2 to 0.4 parts by mass of Artemisia argyi-coupled modified nano zinc oxide and 20 to 40 parts by mass of calcium chloride aqueous solution, wherein the mass concentration of calcium chloride aqueous solution is 2.5 to 5%.

[0036] In one embodiment, in step f), the composite emulsion is uniformly sprayed onto the surface of Artemisia argyi-coupled modified nano zinc oxide at a uniform spraying speed of 2 to 200 ml / min.

[0037] A stone-like paint containing hydrophobic antibacterial particles prepared using the hydrophobic antibacterial particles described in this invention, wherein the stone-like paint containing hydrophobic antibacterial particles has the following composition and proportions:

[0038] Resin: 10-30 parts by weight;

[0039] Colored sand: 50-70 parts by weight;

[0040] Hydrophobic antibacterial granules: 0.1–5 parts by weight;

[0041] Titanium dioxide: 5-15 parts by weight;

[0042] Thickener: 0.2–0.5 parts by weight;

[0043] Defoamer: 0.1–0.3 parts by weight;

[0044] Wetting and dispersing agent: 0.2–0.6 parts by weight;

[0045] Film-forming aid: 0.2 to 0.5 parts by weight.

[0046] In one embodiment, the resin is at least one selected from pure acrylic resin, silicone acrylic resin, styrene acrylic resin, and vinyl acetate acrylic resin.

[0047] In one embodiment, the titanium dioxide is either rutile titanium dioxide or anatase titanium dioxide.

[0048] In one embodiment, the thickener is any one or two of hydroxyethyl cellulose ether, polyacrylate, polyurethane thickener, and associative alkali-swellable thickener.

[0049] In one embodiment, the defoamer is at least one of mineral oils, organosilicon compounds (such as Dow Corning DC-62), and polyether compounds (such as polyether siloxanes, polyethylene glycol, etc.).

[0050] In one embodiment, the wetting and dispersing agent is at least one of acrylic acid, alkyl hydroxyammonium salts (e.g., BYK-180), high molecular weight carboxylic acid, and modified polysiloxane.

[0051] In one embodiment, the film-forming aid is at least one of alcohols (e.g., propylene glycol, ethylene glycol, etc.), alcohol esters (e.g., dodecyl alcohol esters), and alcohol ethers (e.g., propylene glycol methyl ether PM, propylene glycol ethyl ether, propylene glycol butyl ether, etc.).

[0052] A method for preparing the aforementioned stone-like paint containing hydrophobic antibacterial particles includes the following steps: under stirring, colored sand, hydrophobic antibacterial particles, titanium dioxide, thickener, defoamer, wetting and dispersing agent, and film-forming aid are added sequentially to a specified amount of resin, and the mixture is stirred and mixed evenly to obtain the aforementioned stone-like paint containing hydrophobic antibacterial particles.

[0053] Compared with the prior art, the present invention has the following significant advantages:

[0054] This invention first modifies zinc oxide sequentially using Artemisia argyi extract and a silane coupling agent. A composite emulsion is then prepared by compounding a polylysine-modified polyurea emulsion with a sodium alginate-gelatin solution. This composite emulsion is then coated with Artemisia argyi-coupled modified nano-zinc oxide to form spherical particles. These spherical particles are then cross-linked with calcium chloride to obtain hydrophobic antibacterial particles with excellent antibacterial, hydrophobic, and durable antibacterial properties. Adding these hydrophobic antibacterial particles to stone paint results in a stone paint containing these particles that not only possesses excellent antibacterial, hydrophobic, and durable antibacterial properties but also has low light requirements, exhibiting good antibacterial performance in both visible and dark environments. This makes it widely applicable in the field of functional coatings and has significant application value. Furthermore, the preparation method of this invention is economical and practical, with a simple and low-cost process. The raw materials are readily available, and the Artemisia argyi extract used is abundant and eco-friendly. It requires no special equipment or stringent conditions, making it easy to scale up production and possessing strong industrial application value. Attached Figure Description

[0055] Figure 1 The image shows the Artemisia argyi-modified nano-zinc oxide prepared in Example 1 of this invention;

[0056] Figure 2 The infrared spectrum of Artemisia argyi-coupled modified nano-zinc oxide prepared in Example 1 of this invention;

[0057] Figure 3 This is a water contact angle diagram of the hydrophobic antibacterial particles prepared in Example 1 of the present invention;

[0058] Figure 4 The images show the number of Staphylococcus aureus colonies after seven days of resistance to hydrophobic antibacterial particles prepared in Example 1 of the present invention and comparative hydrophobic antibacterial particles prepared in Comparative Examples 1-3.

[0059] Figure 5 The images show the Staphylococcus aureus colony diagrams of the real stone paint coating containing hydrophobic antibacterial particles prepared in Example 1 of the present invention, and the comparative real stone paint coatings prepared in Comparative Example 1 and Comparative Example 3, under dark and visible light irradiation conditions.

[0060] Figure 6 This is a water contact angle diagram of the comparative hydrophobic antibacterial particles prepared in Comparative Example 1 of the present invention;

[0061] Figure 7 Figure a) is a schematic diagram of the preparation of orange peel extract used in Comparative Example 5 of the present invention; Figure b) is a picture of orange peel soaked in ethanol aqueous solution; Figure b) is a picture of the prepared orange peel extract.

[0062] Figure 8 Image of orange peel modified nano zinc oxide prepared in Comparative Example 5 of this invention;

[0063] Figure 9 The images show the coated plates formed by coating arginine-modified polyurea emulsion prepared in Comparative Example 6 and polylysine-modified polyurea emulsion prepared in Example 1 onto tinplate sheets and drying them, after being immersed in water and removed. In the images, a) is the coated plate of arginine-modified polyurea emulsion, and b) is the coated plate of polylysine-modified polyurea emulsion.

[0064] Figure 10 The figures show the coating films of the arginine-modified polyurea emulsion prepared in Comparative Example 6 and the polylysine-modified polyurea emulsion prepared in Example 1, immersed in water, where a) is the coating film of the arginine-modified polyurea emulsion and b) is the coating film of the polylysine-modified polyurea emulsion. Detailed Implementation

[0065] The technical solution of the present invention will be further described in detail and completely below with reference to the embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the manufacturer.

[0066] Example 1

[0067] I. Preparation of hydrophobic antibacterial particles

[0068] a) Soak 5g of dried mugwort in 45g of 60wt% ethanol aqueous solution at 70℃ for 30 minutes. After soaking, filter to obtain mugwort extract for later use.

[0069] Add 4.3902g of zinc acetate dihydrate to 20g of deionized water and stir magnetically for 30 minutes to fully dissolve the zinc acetate dihydrate in the deionized water. Then, add 2g of ammonia water and 5g of Artemisia argyi extract dropwise. After the addition is complete, stir the reaction solution at room temperature for 3 hours (stirring speed is 300rpm). After the reaction is completed, filter the reaction solution under vacuum. Wash the obtained filter cake with anhydrous ethanol and deionized water respectively, and then dry it at 125℃ for 7 hours to obtain Artemisia argyi modified nano zinc oxide.

[0070] b) Take 1g of the Artemisia argyi modified nano zinc oxide obtained in step a), add it to 30g of ethanol, and ultrasonically disperse it for 30 minutes to make the Artemisia argyi modified nano zinc oxide uniformly dispersed in ethanol. Then add 5g of silane coupling agent KH570 and 10g of deionized water. The resulting mixture is stirred at 85℃ for 1 hour (stirring speed is 350rpm). After the reaction is completed, the reaction solution is cooled to room temperature and centrifuged. The separated precipitate is washed with ethanol (to remove excess water and oily substances) and filtered. The filtered product is dried at 80℃ for 8 hours to obtain powdered Artemisia argyi-coupled modified nano zinc oxide.

[0071] c) Add 3.5g of isophorone diisocyanate to the reactor, and add 10.5g of polyetheramine D2000 dropwise at 40°C. After the addition is complete, maintain the temperature and stir for 2.5 hours (stirring speed 200rpm); then raise the temperature to 80°C and add 0.47g of... 2,2-Bis(hydroxymethyl)butyric acid was added, and the mixture was kept at a constant temperature and stirred for 1 hour (stirring speed of 205 rpm). Then, while maintaining the temperature at 80°C, 0.08 g of ε-polylysine was added, and the mixture was kept at a constant temperature and stirred for 1.5 hours. Next, the temperature was lowered to 70°C, and 0.14 g of trimethylolpropane was added, and the mixture was kept at a constant temperature and stirred for 1 hour. The temperature was then lowered further to 50°C, and 0.38 g of triethylamine was added, and the mixture was kept at a constant temperature and stirred for 15 minutes. Finally, the temperature was lowered to 35°C, and 20 g of deionized water was added dropwise (to emulsify the prepolymer). After the addition was complete, the mixture was kept at a constant temperature and stirred for 0.5 hours (stirring speed of 500 rpm) to obtain a polylysine-modified polyurea emulsion.

[0072] d) Add 0.204g sodium alginate and 0.204g gelatin to 20ml deionized water. After the addition is complete, keep warm and stir at 60℃ for 5 hours to obtain sodium alginate-gelatin solution.

[0073] e) Mix 0.18g of the polylysine-modified polyurea emulsion from step c) with 20g of the sodium alginate-gelatin solution from step d) at room temperature for 40 minutes to ensure uniform mixing (stirring speed is 500 rpm) and obtain a composite emulsion.

[0074] f) The composite emulsion was uniformly sprayed onto the surface of Artemisia argyi-coupled modified nano-zinc oxide at a constant spray rate of 20 ml / min. The mixture was shaken to ensure uniform distribution, allowing the composite emulsion to be coated with Artemisia argyi-coupled modified nano-zinc oxide to form spherical particles. The spherical particles were then added to 20 g of a 5% calcium chloride aqueous solution. The resulting mixture was subjected to a cross-linking reaction at room temperature for 1.5 hours. After the reaction was completed, the resulting reactant was freeze-dried under vacuum to a constant weight (freezing temperature: -40℃, freezing time: 24 hours) to obtain the hydrophobic antibacterial particles.

[0075] II. Preparation of Stone Paint Containing Hydrophobic Antibacterial Particles

[0076] While stirring at 600 rpm, 65 g of natural colored sand, 2 g of hydrophobic antibacterial particles, 12 g of rutile titanium dioxide, 0.2 g of thickener hydroxyethyl cellulose ether, 0.25 g of defoamer Dow Corning DC-62, 0.35 g of BYK-180 wetting and dispersing agent, and 0.2 g of dodecyl alcohol ester film-forming aid were added sequentially to 20 g of styrene-acrylic resin. The mixture was stirred at room temperature for 50 minutes to ensure that all components were mixed evenly, thus obtaining a stone-like paint containing hydrophobic antibacterial particles.

[0077] Figure 1 Images of the Artemisia argyi-modified nano-zinc oxide prepared in this embodiment; from Figure 1 As can be seen, the prepared mugwort-modified nano zinc oxide is a light blue-green powder solid. The color of the product is close to that of mugwort, indicating that the mugwort extract has been successfully modified. Furthermore, the particles in the powder solid are evenly distributed and there is basically no clumping.

[0078] Figure 2 The image shows the infrared spectrum of the Artemisia argyi-coupled modified nano-zinc oxide prepared in this embodiment. Figure 2 It is evident that the prepared Artemisia argyi-coupled modified nano zinc oxide exhibited characteristic peaks of silane coupling agents, indicating that the silane coupling agent modification in step b) was successful.

[0079] Figure 3 This is a water contact angle diagram of the hydrophobic antibacterial particles prepared in this embodiment. Figure 3 It can be seen that the prepared hydrophobic antibacterial particles have a water contact angle of 119.5°, indicating good hydrophobicity.

[0080] The antibacterial properties of the hydrophobic antibacterial particles prepared in this embodiment and the stone paint containing hydrophobic antibacterial particles were tested. The test methods are as follows:

[0081] 1) Antibacterial performance test of hydrophobic antibacterial particles

[0082] Referring to WS / T650-2019 "Evaluation Method for Antibacterial and Bacteriostatic Effects", hydrophobic antibacterial particles were compared with bacteria at a concentration of 10. 5 The bacterial concentration of Staphylococcus aureus suspension was observed after co-culturing for 1, 3, and 7 days to evaluate its antibacterial rate R and antibacterial durability. The formula for calculating the antibacterial rate R is as follows:

[0083] R (%) = (BC) / B × 100

[0084] In the formula: R is the antibacterial rate (%) of the hydrophobic antibacterial particle sample; B is the average number of recovered colonies (CFU / mL) of the blank control sample over 24 hours; C is the average number of recovered colonies (CFU / mL) of the hydrophobic antibacterial particle sample over 24 hours.

[0085] The test results are shown in Table 1 and Figure 4 As shown.

[0086] 2) Antibacterial performance test of stone paint containing hydrophobic antibacterial particles

[0087] Referring to GB / T 30706-2014 "Test Methods and Evaluation of Antibacterial Properties of Photocatalytic Antibacterial Materials and Products under Visible Light Irradiation" and GB / T 21866-2008 "Determination of Antibacterial Properties and Antibacterial Effects of Antibacterial Coatings (Films)", Staphylococcus aureus was used as the inoculum to determine the antibacterial activity of stone-like paint containing hydrophobic antibacterial particles. A 2mm thick coating of hydrophobic antibacterial particles was prepared using a scraping frame. After drying, the coating was cut into 50mm×50mm film plates for antibacterial testing. 0.4mL of 10 5 A bacterial suspension of (CFU / mL) was used to cover the surface of a coated board with a PE film measuring 40×40 mm. Visible light sources in the 400-800 nm wavelength range were used as the ambient light conditions to test the antibacterial rate under both visible light and dark environments. After incubation at 37℃ for 24 hours, the number of bacteria on the coating surface was observed, and the antibacterial rate R was calculated. 总 and photocatalytic antibacterial rate R 光 .

[0088] R 总 (%) = (C0-C1) / C0×100; R 光 (%) = (B1-C1) / B1×100

[0089] In the formula: R 总 R 光 These are the antibacterial rate of the test sample and the antibacterial rate of the test sample under visible light irradiation (%); C0 is the viable count of the control sample after culture in a light environment (CFU / piece); C1 is the viable count of the photocatalytic sample after culture in a light environment (CFU / piece); and B1 is the viable count of the photocatalytic sample after culture in a dark environment (CFU / piece).

[0090] The test results are shown in Table 2 and Figure 5 As shown.

[0091] Example 2

[0092] I. Preparation of hydrophobic antibacterial particles

[0093] a) Soak 10g of dried mugwort in 90g of 70wt% ethanol aqueous solution at a temperature of 65℃ for 45 minutes. After soaking, filter to obtain mugwort extract for later use.

[0094] Add 8.7804g of zinc acetate dihydrate to 40g of deionized water and stir magnetically for 45 minutes to fully dissolve the zinc acetate dihydrate in the deionized water. Then, add 3g of ammonia water and 3g of Artemisia argyi extract dropwise. After the addition is complete, stir the reaction solution at room temperature for 4 hours (stirring speed is 450rpm). After the reaction is completed, filter the reaction solution under vacuum. Wash the obtained filter cake with anhydrous ethanol and deionized water respectively, and then dry it at 100℃ for 9 hours to obtain Artemisia argyi modified nano zinc oxide.

[0095] b) Take 2g of the Artemisia argyi modified nano zinc oxide obtained in step a), add it to 60g of ethanol, and ultrasonically disperse it for 40 minutes to make the Artemisia argyi modified nano zinc oxide uniformly dispersed in ethanol. Then add 10g of silane coupling agent KH570 and 20g of deionized water. The resulting mixture is stirred at 80℃ for 2 hours (stirring speed is 400rpm). After the reaction is completed, the reaction solution is cooled to room temperature and centrifuged. The separated precipitate is washed with ethanol (to remove excess water and oily substances) and filtered. The filtered product is dried at 70℃ for 11 hours to obtain powdered Artemisia argyi-coupled modified nano zinc oxide.

[0096] c) Add 7g of isophorone diisocyanate to the reactor, and add 21g of polyetheramine D2000 dropwise at 45°C. After the addition is complete, maintain the temperature and stir for 2 hours (stirring speed 195 rpm). Then raise the temperature to 85°C and add 0.94g of dimethylolpropionic acid. After the addition is complete, maintain the temperature and stir for 1 hour (stirring speed 180 rpm). Next, keep the temperature at 80°C and add 0.16g of ε-polylysine. After the addition is complete, maintain the temperature and stir for 1.5 hours. Then lower the temperature to 75°C and add 0.28g of trimethylolpropane. After the addition is complete, maintain the temperature and stir for 0.5 hours. Continue to lower the temperature to 50°C and add 0.76g of dimethylethanolamine. After the addition is complete, maintain the temperature and stir for 20 minutes. Finally, lower the temperature to 35°C and add 40g of deionized water (to emulsify the prepolymer). After the addition is complete, maintain the temperature and stir for 1 hour (stirring speed 700 rpm) to obtain polylysine-modified polyurea emulsion.

[0097] d) Add 0.408g sodium alginate and 0.408g gelatin to 20ml deionized water. After the addition is complete, keep warm and stir at 65℃ for 5 hours to obtain sodium alginate-gelatin solution.

[0098] e) Mix 0.12g of the polylysine-modified polyurea emulsion from step c) with 20g of the sodium alginate-gelatin solution from step d) at room temperature for 45 minutes to ensure uniform mixing (stirring speed is 550 rpm) to obtain a composite emulsion.

[0099] f) The composite emulsion was uniformly sprayed onto the surface of Artemisia argyi-coupled modified nano-zinc oxide at a constant spray rate of 100 ml / min. The mixture was shaken to ensure uniform distribution, so that the composite emulsion was coated with Artemisia argyi-coupled modified nano-zinc oxide to form spherical particles. The spherical particles were added to 30 g of a 4% calcium chloride aqueous solution. The resulting mixture was subjected to a cross-linking reaction at room temperature for 1 hour. After the reaction was completed, the resulting reactant was freeze-dried under vacuum to a constant weight (freezing temperature: -20℃, freezing time: 72 hours) to obtain the hydrophobic antibacterial particles.

[0100] II. Preparation of Stone Paint Containing Hydrophobic Antibacterial Particles

[0101] While stirring at 700 rpm, 65 g of quartz sand, 4 g of hydrophobic antibacterial particles, 10 g of rutile titanium dioxide, 0.2 g of polyacrylate thickener, 0.25 g of polyether siloxane defoamer, 0.35 g of BYK-180 wetting and dispersing agent, and 0.2 g of propylene glycol film-forming aid were added sequentially to 20 g of vinyl acetate resin. The mixture was stirred at room temperature for 40 minutes to ensure that all components were mixed evenly, thus obtaining a stone-like paint containing hydrophobic antibacterial particles.

[0102] The antibacterial properties of the hydrophobic antibacterial particles prepared in this embodiment and the stone paint containing the hydrophobic antibacterial particles were tested. The test method was the same as described in Example 1. The antibacterial properties test results of the hydrophobic antibacterial particles are shown in Table 1, and the antibacterial properties test results of the stone paint containing the hydrophobic antibacterial particles are shown in Table 2.

[0103] Example 3

[0104] I. Preparation of hydrophobic antibacterial particles

[0105] a) Soak 10g of dried mugwort in 90g of 65wt% ethanol aqueous solution at 60℃ for 50 minutes. After soaking, filter to obtain mugwort extract for later use.

[0106] Add 8.7804g of zinc acetate dihydrate to 40g of deionized water and stir magnetically for 40 minutes to fully dissolve the zinc acetate dihydrate in the deionized water. Then, add 2g of ammonia water and 5g of Artemisia argyi extract dropwise. After the addition is complete, stir the reaction solution at room temperature for 5 hours (stirring speed is 250rpm). After the reaction is completed, filter the reaction solution under vacuum. Wash the obtained filter cake with anhydrous ethanol and deionized water respectively, and then dry it at 80℃ for 12 hours to obtain Artemisia argyi modified nano zinc oxide.

[0107] b) Take 1.5g of the Artemisia argyi modified nano zinc oxide obtained in step a), add it to 45g of ethanol, and ultrasonically disperse for 30 minutes to make the Artemisia argyi modified nano zinc oxide uniformly dispersed in ethanol. Then add 7.5g of silane coupling agent KH570 and 15g of deionized water. The resulting mixture is stirred at 85℃ for 3 hours (stirring speed is 390rpm). After the reaction is completed, the reaction solution is cooled to room temperature and centrifuged. The separated precipitate is washed with ethanol (to remove excess water and oily substances) and filtered. The filtered product is dried at 75℃ for 9 hours to obtain powdered Artemisia argyi-coupled modified nano zinc oxide.

[0108] c) Add 7g of isophorone diisocyanate to the reactor, and add 21g of polyetheramine ED900 dropwise at 45°C. After the addition is complete, maintain the temperature and stir for 2 hours (stirring speed 195 rpm). Then raise the temperature to 85°C and add 0.94g of dimethylolpropionic acid. After the addition is complete, maintain the temperature and stir for 1.5 hours (stirring speed 215 rpm). Next, keep the temperature at 85°C and add 0.16g of α-polylysine. After the addition is complete, maintain the temperature and stir for 1 hour. Then lower the temperature to 70°C and add 0.28g of trimethylolpropane. After the addition is complete, maintain the temperature and stir for 1 hour. Continue to lower the temperature to 50°C and add 0.76g of dimethylethanolamine. After the addition is complete, maintain the temperature and stir for 15 minutes. Finally, lower the temperature to 30°C and add 40g of deionized water (to emulsify the prepolymer). After the addition is complete, maintain the temperature and stir for 1.5 hours (stirring speed 600 rpm) to obtain polylysine-modified polyurea emulsion.

[0109] d) Add 0.816g sodium alginate and 0.816g gelatin to 20ml deionized water. After the addition is complete, keep warm and stir at 70℃ for 6 hours to obtain sodium alginate-gelatin solution.

[0110] e) Mix 0.18g of the polylysine-modified polyurea emulsion from step c) with 20g of the sodium alginate-gelatin solution from step d) at room temperature for 35 minutes to ensure uniform mixing (stirring speed is 600 rpm) and obtain a composite emulsion.

[0111] f) The composite emulsion was uniformly sprayed onto the surface of Artemisia argyi-coupled modified nano-zinc oxide at a constant spray rate of 150 ml / min. The mixture was shaken to ensure uniform distribution, allowing the composite emulsion to be coated with Artemisia argyi-coupled modified nano-zinc oxide to form spherical particles. The spherical particles were then added to 40 g of a 2.5% calcium chloride aqueous solution. The resulting mixture was subjected to a cross-linking reaction at room temperature for 1 hour. After the reaction was completed, the resulting reactant was freeze-dried under vacuum to a constant weight (freezing temperature: -35°C, freezing time: 48 hours) to obtain the hydrophobic antibacterial particles.

[0112] II. Preparation of Stone Paint Containing Hydrophobic Antibacterial Particles

[0113] While stirring at 800 rpm, 65 g of permanently dyed colored sand, 2 g of hydrophobic antibacterial particles, 12 g of anatase titanium dioxide, 0.2 g of associative alkali-swelling thickener, 0.25 g of Dow Corning DC-62 defoamer, 0.35 g of BYK-180 wetting and dispersing agent, and 0.2 g of dodecyl alcohol ester film-forming aid were added sequentially to 20 g of silicone-acrylic resin. The mixture was stirred at room temperature for 30 minutes to ensure that all components were mixed evenly, thus obtaining a stone-like paint containing hydrophobic antibacterial particles.

[0114] The antibacterial properties of the hydrophobic antibacterial particles prepared in this embodiment and the stone paint containing the hydrophobic antibacterial particles were tested. The test method was the same as described in Example 1. The antibacterial properties test results of the hydrophobic antibacterial particles are shown in Table 1, and the antibacterial properties test results of the stone paint containing the hydrophobic antibacterial particles are shown in Table 2.

[0115] Comparative Example 1

[0116] The only difference between this comparative example and Example 1 is that Artemisia argyi extract was not added during the preparation of nano-zinc oxide in step a). All other contents are the same as described in Example 1. The specific preparation process is as follows:

[0117] I. Comparative Preparation of Hydrophobic Antibacterial Particles

[0118] a) Add 4.3902g of zinc acetate dihydrate to 20g of deionized water and stir magnetically for 30 minutes. Gradually add 3g of ammonia water dropwise while maintaining a speed of 300rpm and continue stirring magnetically for 3 hours. Vacuum filter the reaction precipitate. Wash the filter cake with anhydrous ethanol and deionized water and dry it at 125℃ for 7 hours to obtain nano zinc oxide.

[0119] b) Take 1g of the nano zinc oxide obtained in step a), add it to 30g of ethanol, and ultrasonically disperse it for 30 minutes to make the nano zinc oxide uniformly dispersed in the ethanol. Then add 5g of silane coupling agent KH570 and 10g of deionized water. The resulting mixture is stirred at 85℃ for 1 hour (stirring speed is 350rpm). After the reaction is completed, the reaction solution is cooled to room temperature and centrifuged. The separated precipitate is washed with ethanol (to remove excess water and oily substances) and filtered. The filtered product is dried at 80℃ for 8 hours to obtain coupling modified nano zinc oxide.

[0120] c) Same as described in Example 1;

[0121] d) Same as described in Example 1;

[0122] e) Same as described in Example 1;

[0123] f) The composite emulsion was uniformly sprayed onto the surface of Artemisia argyi-coupled modified nano-zinc oxide at a constant spray rate of 20 ml / min. The mixture was shaken to ensure uniform coating of the composite emulsion with Artemisia argyi-coupled modified nano-zinc oxide, forming spherical particles. The spherical particles were added to 20 g of a 5% calcium chloride aqueous solution. The resulting mixture was subjected to a cross-linking reaction at room temperature for 1.5 hours. After the reaction was completed, the resulting reactant was freeze-dried under vacuum to a constant weight (freezing temperature -40℃, freezing time 24 hours) to obtain the comparative hydrophobic antibacterial particles.

[0124] II. Comparison of the preparation of real stone paint

[0125] While stirring at 600 rpm, 65 g of natural colored sand, 2 g of contrast hydrophobic antibacterial particles, 12 g of rutile titanium dioxide, 0.2 g of thickener hydroxyethyl cellulose ether, 0.25 g of defoamer Dow Corning DC-62, 0.35 g of BYK-180 wetting and dispersing agent, and 0.2 g of dodecyl alcohol ester film-forming aid were added sequentially to 20 g of styrene-acrylic resin. The mixture was stirred at room temperature for 50 minutes to ensure that all components were mixed evenly, thus obtaining the contrast stone paint.

[0126] Figure 6 This is a water contact angle diagram of the comparative hydrophobic antibacterial particles prepared in this comparative example. Figure 6 It is evident that the water contact angle of the prepared comparative hydrophobic antibacterial particles is 98.1°, which is much smaller than the 119.5° water contact angle of the hydrophobic antibacterial particles prepared in Example 1. This indicates that the hydrophobicity of the comparative hydrophobic antibacterial particles prepared in this example is worse than that of the hydrophobic antibacterial particles prepared in Example 1. Therefore, it is clear that the modification of Artemisia argyi extract has a significant impact on the hydrophobicity of antibacterial particles during their preparation.

[0127] The antibacterial properties of the comparative hydrophobic antibacterial particles and the comparative stone paint prepared in this comparative example were tested using the same methods as described in Example 1. The antibacterial performance test results of the comparative hydrophobic antibacterial particles are shown in Table 1 and... Figure 4 As shown in Table 2, the test results of the antibacterial properties of the stone paint are compared. Figure 5 As shown.

[0128] Comparative Example 2

[0129] The only difference between this comparative example and Example 2 is that in the preparation of Artemisia argyi-coupled modified nano zinc oxide, Artemisia argyi and coupling modification are performed in one pot. The silane coupling agent KH570 used in the coupling modification is added to the reaction solution after Artemisia argyi modification in step a). All other contents are the same as described in Example 1. The specific preparation process is as follows:

[0130] I. Comparative Preparation of Hydrophobic Antibacterial Particles

[0131] a) Soak 10g of dried mugwort in 90g of 70wt% ethanol aqueous solution at a temperature of 65℃ for 45 minutes. After soaking, filter to obtain mugwort extract for later use.

[0132] Add 8.7804g of zinc acetate dihydrate to 40g of deionized water and stir magnetically for 45 minutes to fully dissolve the zinc acetate dihydrate in the deionized water. Then, add 3g of ammonia water and 3g of Artemisia argyi extract dropwise. After the addition is complete, stir the mixture at room temperature for 4 hours (stirring speed is 450rpm) to obtain a green solution containing Artemisia argyi modified nano zinc oxide, which is ready for use.

[0133] b) Add 60g of ethanol to the green solution containing Artemisia argyi modified nano zinc oxide obtained in step a), and ultrasonically disperse for 40 minutes. Then add 10g of silane coupling agent KH570 and 20g of deionized water to the resulting mixture. Stir the mixture at 80℃ for 2 hours (stirring speed 400rpm). After the reaction is completed, cool the reaction solution to room temperature and centrifuge. Wash the separated precipitate with ethanol (to remove excess water and oily substances) and filter. Dry the filtered product at 70℃ for 11 hours to obtain the comparative Artemisia argyi-coupled modified nano zinc oxide.

[0134] c) Same as described in Example 2;

[0135] d) Same as described in Example 2;

[0136] e) Same as described in Example 2;

[0137] f) The composite emulsion was uniformly sprayed onto the surface of Artemisia argyi-coupled modified nano-zinc oxide at a constant spray rate of 100 ml / min. The mixture was shaken to ensure uniform distribution, so that the composite emulsion was coated with Artemisia argyi-coupled modified nano-zinc oxide to form spherical particles. The spherical particles were added to 30 g of a 4% calcium chloride aqueous solution. The resulting mixture was subjected to a cross-linking reaction at room temperature for 1 hour. The reaction was then terminated, and the resulting reactant was freeze-dried under vacuum to a constant weight (freezing temperature: -20°C, freezing time: 72 hours) to obtain the comparative hydrophobic antibacterial particles.

[0138] II. Comparison of the preparation of real stone paint

[0139] While stirring at 700 rpm, 65 g of quartz sand, 4 g of contrast hydrophobic antibacterial particles, 10 g of rutile titanium dioxide, 0.2 g of polyacrylate thickener, 0.25 g of polyether siloxane defoamer, 0.35 g of BYK-180 wetting and dispersing agent, and 0.2 g of propylene glycol film-forming aid were added sequentially to 20 g of vinyl acetate resin. The mixture was stirred at room temperature for 40 minutes to ensure that all components were mixed evenly, thus obtaining the contrast stone paint.

[0140] The antibacterial properties of the comparative hydrophobic antibacterial particles and the comparative stone paint prepared in this comparative example were tested using the same methods as described in Example 1. The antibacterial performance test results of the comparative hydrophobic antibacterial particles are shown in Table 1 and... Figure 4 As shown in Table 2, the test results of the antibacterial performance of the stone paint are compared.

[0141] Comparative Example 3

[0142] The only difference between this comparative example and Example 3 is that Artemisia argyi extract and polylysine-modified polyurea emulsion were not added during the preparation of the hydrophobic antibacterial particles. All other contents are the same as described in Example 3. The specific preparation process is as follows:

[0143] I. Comparative Preparation of Hydrophobic Antibacterial Particles

[0144] a) Add 8.7804 g of zinc acetate dihydrate to 40 g of deionized water and stir magnetically for 40 minutes to fully dissolve the zinc acetate dihydrate in the deionized water. Then, add 3 g of ammonia water dropwise. After the addition is complete, stir the reaction at room temperature for 5 hours (stirring speed is 250 rpm). After the reaction is completed, filter the reaction solution under vacuum. Wash the obtained filter cake with anhydrous ethanol and deionized water respectively, and then dry it at 80℃ for 12 hours to obtain nano zinc oxide.

[0145] b) Take 1.5g of the nano zinc oxide obtained in step a), add it to 45g of ethanol, and ultrasonically disperse it for 30 minutes to make the Artemisia argyi modified nano zinc oxide uniformly dispersed in ethanol. Then add 7.5g of silane coupling agent KH570 and 15g of deionized water. The resulting mixture is stirred at 85℃ for 3 hours (stirring speed is 390rpm). After the reaction is completed, the reaction solution is cooled to room temperature and centrifuged. The separated precipitate is washed with ethanol (to remove excess water and oily substances) and filtered. The filtered product is dried at 75℃ for 9 hours to obtain the coupling modified nano zinc oxide.

[0146] c) Add 0.816g sodium alginate and 0.816g gelatin to 20ml deionized water. After the addition is complete, keep warm and stir at 70℃ for 6 hours to obtain sodium alginate-gelatin solution.

[0147] d) The sodium alginate-gelatin solution was uniformly sprayed onto the surface of Artemisia argyi-coupled modified nano zinc oxide at a constant spray rate of 150 ml / min. The mixture was shaken to ensure uniform distribution, so that the composite emulsion was coated with Artemisia argyi-coupled modified nano zinc oxide to form spherical particles. The spherical particles were added to 40 g of a 2.5% calcium chloride aqueous solution. The resulting mixture was subjected to a cross-linking reaction at room temperature for 1 hour. After the reaction was completed, the resulting reactant was freeze-dried under vacuum to a constant weight (freezing temperature: -35℃, freezing time: 48 hours) to obtain the comparative hydrophobic antibacterial particles.

[0148] II. Comparison of the preparation of real stone paint

[0149] While stirring at 800 rpm, 65 g of permanently dyed colored sand, 2 g of contrast hydrophobic antibacterial particles, 12 g of anatase titanium dioxide, 0.2 g of associative alkali-swelling thickener, 0.25 g of Dow Corning DC-62 defoamer, 0.35 g of BYK-180 wetting and dispersing agent, and 0.2 g of dodecyl alcohol ester film-forming aid were added sequentially to 20 g of silicone-acrylic resin. The mixture was stirred at room temperature for 30 minutes to ensure that all components were mixed evenly, thus obtaining the contrast stone paint.

[0150] The antibacterial properties of the comparative hydrophobic antibacterial particles and the comparative stone paint prepared in this comparative example were tested using the same methods as described in Example 1. The antibacterial performance test results of the comparative hydrophobic antibacterial particles are shown in Table 1 and... Figure 4 As shown in Table 2, the test results of the antibacterial properties of the stone paint are compared. Figure 5 As shown.

[0151] Comparative Example 4

[0152] The only difference between this comparative example and Example 1 is that in step f), the composite emulsion is added dropwise to the surface of Artemisia argyi-coupled modified nano-zinc oxide using a dropper. All other aspects are the same as described in Example 1. The specific preparation process is as follows:

[0153] I. Comparative Preparation of Hydrophobic Antibacterial Particles

[0154] a) As described in Example 1;

[0155] b) As described in Example 1;

[0156] c) Same as described in Example 1;

[0157] d) Same as described in Example 1;

[0158] f) The composite emulsion was uniformly added to the surface of Artemisia argyi-coupled modified nano-zinc oxide by dropper, and shaken evenly to coat the composite emulsion with Artemisia argyi-coupled modified nano-zinc oxide, forming spherical particles. The spherical particles were added to 20g of calcium chloride aqueous solution with a mass concentration of 5%, and the resulting mixture was subjected to a cross-linking reaction at room temperature for 1.5 hours. After the reaction was stopped, the resulting reactant was freeze-dried under vacuum to a constant weight (freezing temperature of -40℃, freezing time of 24 hours) to obtain the comparative hydrophobic antibacterial particles.

[0159] II. Comparison of the preparation of real stone paint

[0160] While stirring at 600 rpm, 65 g of natural colored sand, 2 g of contrast hydrophobic antibacterial particles, 12 g of rutile titanium dioxide, 0.2 g of thickener hydroxyethyl cellulose ether, 0.25 g of defoamer Dow Corning DC-62, 0.35 g of BYK-180 wetting and dispersing agent, and 0.2 g of dodecyl alcohol ester film-forming aid were added sequentially to 20 g of styrene-acrylic resin. The mixture was stirred at room temperature for 50 minutes to ensure that all components were mixed evenly, thus obtaining the contrast stone paint.

[0161] The antibacterial properties of the comparative hydrophobic antibacterial particles and the comparative stone paint prepared in this comparative example were tested using the same methods as described in Example 1. The antibacterial properties of the comparative hydrophobic antibacterial particles are shown in Table 1, and the antibacterial properties of the comparative stone paint are shown in Table 2.

[0162] Comparative Example 5

[0163] In this comparative example, orange peel extract was used instead of artemisia extract to modify zinc oxide, as detailed below:

[0164] Soak 5g of orange peel in 45g of 60wt% ethanol aqueous solution at 70℃ for 30 minutes. After soaking, filter to obtain orange peel extract for later use.

[0165] 4.3902 g of zinc acetate dihydrate was added to 20 g of deionized water and magnetically stirred for 30 minutes to fully dissolve the zinc acetate dihydrate in the deionized water. Then, 2 g of ammonia water and 5 g of orange peel extract were added dropwise. After the addition was complete, the mixture was stirred at room temperature for 3 hours (stirring speed of 300 rpm). After the reaction was completed, the reaction solution was vacuum filtered. The resulting filter cake was washed with anhydrous ethanol and deionized water, and then dried at 125 °C for 7 hours to obtain orange peel modified nano zinc oxide.

[0166] Figure 7 This is a schematic diagram illustrating the preparation of the orange peel extract used in this comparative example. Figure a) is a picture of orange peel soaked in an ethanol-water solution; Figure b) is a picture of the prepared orange peel extract; from Figure 7 It is evident that the orange peel extract used was orange in color.

[0167] Figure 8 Here is an image of the orange peel-modified zinc oxide prepared in this comparative example; from Figure 8 It is evident that the prepared orange peel modified zinc oxide is a black solid, and the black solid is granular, with agglomeration and difficult dispersion, resulting in low yield and making it unsuitable for subsequent experimental preparation.

[0168] Comparative Example 6

[0169] In this comparative example, arginine was used to replace polylysine in the preparation of the modified polyurea emulsion, as detailed below:

[0170] Add 3.5g of isophorone diisocyanate to the reactor, and then add 10.5g of polyetheramine D2000 dropwise at 40℃. After the addition is complete, maintain the temperature and stir for 2.5 hours (stirring speed 200rpm); then raise the temperature to 80℃ and add 0.56g of... 2,2-Bis(hydroxymethyl)butyric acid was added, and the mixture was kept at a constant temperature and stirred for 2.5 hours (stirring speed 205 rpm). Then, while maintaining the temperature at 80°C, 0.22 g of arginine was added, and the mixture was kept at a constant temperature and stirred for 1.5 hours. Next, the temperature was lowered to 70°C, and 0.14 g of trimethylolpropane was added, and the mixture was kept at a constant temperature and stirred for 1 hour. The temperature was then lowered further to 50°C, and 0.51 g of triethylamine was added, and the mixture was kept at a constant temperature and stirred for 0.5 hours. Finally, while maintaining the temperature at 50°C, 20 g of deionized water was added dropwise (to emulsify the prepolymer), and the mixture was kept at a constant temperature and stirred for 0.5 hours (stirring speed 500 rpm) to obtain an arginine-modified polyurea emulsion.

[0171] The stability of the arginine-modified polyurea emulsion prepared in this comparative example and the polylysine-modified polyurea emulsion prepared in Example 1 were investigated using the following methods:

[0172] 1) The arginine-modified polyurea emulsion prepared in this comparative example and the polylysine-modified polyurea emulsion prepared in Example 1 were respectively coated onto tinplate sheets. After drying, the coated sheets were immersed in water and then removed. The condition of the coated sheets after removal is as follows. Figure 9 As shown;

[0173] 2) The arginine-modified polyurea emulsion prepared in this comparative example and the polylysine-modified polyurea emulsion prepared in Example 1 were respectively coated onto a polytetrafluoroethylene (PTFE) plate. After drying, the coating film was peeled off the PTFE plate and then cut into 1×1 cm films. The films were then immersed in water, and the results were as follows. Figure 10 As shown.

[0174] Figure 9 Images show the coated plates formed by coating arginine-modified polyurea emulsion (prepared in this comparative example) and polylysine-modified polyurea emulsion (prepared in Example 1) onto tinplate sheets, drying them, and then immersing them in water. In image a), the coated plate is the one with the arginine-modified polyurea emulsion coating, and in image b), the coated plate is the one with the polylysine-modified polyurea emulsion coating. Figure 9 It is evident that the polylysine-modified polyurea emulsion coating plate remained largely unchanged, while the arginine-modified polyurea emulsion coating plate exhibited severe bubbling, indicating that the film formed by the arginine-modified polyurea emulsion has poor water stability.

[0175] Figure 10 Figure 1 shows the coating films of the arginine-modified polyurea emulsion prepared in this comparative example and the polylysine-modified polyurea emulsion prepared in Example 1, immersed in water. In Figure 2, a) is the coating film of the arginine-modified polyurea emulsion, and b) is the coating film of the polylysine-modified polyurea emulsion. Figure 10 It is evident that the arginine-modified polyurea emulsion coating film turned white in water, indicating that the film formed by arginine-modified polyurea has poor water stability.

[0176] Therefore, it can be seen that during the preparation of hydrophobic antibacterial particles, when modifying polyurea emulsions, although arginine and polylysine are both amino acids, the modification effects are significantly different. Polylysine-modified polyurea emulsions have good water stability and are suitable for the subsequent preparation of stone paint, while arginine-modified polyurea emulsions have poor water stability and are not suitable for the subsequent preparation of stone paint. This also shows that the modification effect of polylysine on polyurea emulsions in this invention is unpredictable.

[0177] Table 1. Antibacterial rate test results of hydrophobic antibacterial particles prepared in Examples 1-3 and Comparative Examples 1-3 after 7 days.

[0178] Test sample 1-day antibacterial rate R (%) 3-day antibacterial rate R (%) 7-day antibacterial rate R (%) Example 1 99.9 99.9 99.9 Example 2 99.8 99.7 99.7 Example 3 99.9 99.9 99.9 Comparative Example 1 75.2 73.4 71.1 Comparative Example 2 97.7 95.8 93.2 Comparative Example 3 48.3 47.4 43.6 Comparative Example 4 99.7 99.5 99.3

[0179] Table 2. Test results of total antibacterial rate and photocatalytic anti-Staphylococcus aureus rate of the stone paint coating containing hydrophobic antibacterial particles.

[0180] Test sample <![CDATA[R 总 (%)]]> <![CDATA[R 光 (%)]]> Example 1 96.7 92.1 Example 2 98.4 94.6 Example 3 97.1 93.3 Comparative Example 1 73.3 13.1 Comparative Example 2 95.2 70.9 Comparative Example 3 32.1 3.1 Comparative Example 4 96.2 91.8

[0181] As can be seen from Tables 1 and 2, the method described in this invention (such as Examples 1-3) can obtain hydrophobic antibacterial particles with excellent antibacterial properties and stone paint containing hydrophobic antibacterial particles, which have excellent antibacterial durability and visible light antibacterial effect against Staphylococcus aureus. Moreover, compared with the same conditions without the addition of Artemisia argyi extract (Comparative Example 1), or Artemisia argyi and coupling-modified nano zinc oxide being modified in one pot (Comparative Example 2), or without the addition of polylysine-modified polyurea emulsion and Artemisia argyi extract (Comparative Example 3), all have produced significant improvements. This also shows that the technical solution of this invention, which synthesizes Artemisia argyi modified zinc oxide through Artemisia argyi extract and then modifies it with silane coupling agent KH570 to obtain Artemisia argyi-coupling-modified nano zinc oxide and adds polylysine-modified polyurea emulsion, has a synergistic effect.

[0182] In addition, the total antibacterial rate and photocatalytic antibacterial rate of the stone paint coating containing hydrophobic antibacterial particles prepared in Examples 1-3 are excellent, and they have good antibacterial rates in both visible light and dark environments. This is because the amount of loss of the coating is reduced by adsorption on the surface of sodium alginate-gelatin and polylysine-modified polyurea emulsion, and it still has good antibacterial properties even after a period of use.

[0183] Furthermore, among Examples 1-3, the stone paint of Example 2, which has the highest content of hydrophobic antibacterial particles, has the best antibacterial effect, indicating that the content of hydrophobic antibacterial particles has a certain influence on the antibacterial effect of stone paint.

[0184] Furthermore, the only difference between Comparative Example 4 and Example 1 is the method of adding the composite emulsion. The antibacterial properties of the hydrophobic antibacterial particles prepared in Example 1 and the stone paint coating containing hydrophobic antibacterial particles are slightly better than those of Comparative Example 4, indicating that the method of adding the composite emulsion has a certain influence on the antibacterial properties of the hydrophobic antibacterial particles and the stone paint coating containing hydrophobic antibacterial particles.

[0185] Finally, it should be noted that the above are only some preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A hydrophobic antibacterial particle, characterized in that: First, a composite emulsion is prepared by compounding polylysine-modified polyurea emulsion with sodium alginate-gelatin solution. Then, the composite emulsion is uniformly added to the surface of Artemisia argyi-coupled modified nano zinc oxide. The mixture is shaken evenly to coat the composite emulsion with Artemisia argyi-coupled modified nano zinc oxide, forming spherical particles. The spherical particles are then cross-linked with calcium chloride to obtain the final product. The Artemisia argyi-coupled modified nano zinc oxide is obtained by sequentially modifying zinc oxide with Artemisia argyi extract and a silane coupling agent, wherein the silane coupling agent is KH570.

2. A method for preparing the hydrophobic antibacterial particles according to claim 1, characterized in that, Includes the following steps: a) First, dissolve zinc acetate dihydrate in deionized water, then add ammonia and Artemisia argyi extract dropwise. After the addition is complete, stir the reaction at room temperature for 3-5 hours, collect the solid product, and obtain Artemisia argyi modified nano zinc oxide. b) Disperse Artemisia argyi modified nano zinc oxide in ethanol, then add silane coupling agent and deionized water to it. Stir the mixture at 75-85°C for 1-3 hours, collect the solid product, and obtain Artemisia argyi-coupled modified nano zinc oxide. c) Isocyanate is added to the reactor, and polyetheramine is added dropwise at 40-45°C. After the addition is complete, the mixture is kept warm and stirred for 2-2.5 hours. Then, the temperature is raised to 80-85°C, and a hydrophilic chain extender is added. After the addition is complete, the mixture is kept warm and stirred for 1-1.5 hours. Next, the temperature is kept constant at 80-85°C, and polylysine is added. After the addition is complete, the mixture is kept warm and stirred for 1-1.5 hours. Then, the temperature is lowered to 70-75°C, and a crosslinking agent is added. After the addition is complete, the mixture is kept warm and stirred for 0.5-1 hour. The temperature is further lowered to 45-50°C, and a neutralizing agent is added. After the addition is complete, the mixture is kept warm and stirred for 15-30 minutes. Finally, the temperature is lowered to 30-35°C, and deionized water is added dropwise. After the addition is complete, the mixture is kept warm and stirred for 0.5-1.5 hours to obtain a polylysine-modified polyurea emulsion. d) Add equal masses of sodium alginate and gelatin to deionized water. After the addition is complete, keep warm and stir at 60-70℃ for 5-6 hours to obtain sodium alginate-gelatin solution. e) Mix the polylysine-modified polyurea emulsion from step c) with the sodium alginate-gelatin solution from step d) at room temperature to obtain a composite emulsion. f) The composite emulsion is uniformly added to the surface of Artemisia argyi-coupled modified nano zinc oxide, and shaken evenly to coat the composite emulsion with Artemisia argyi-coupled modified nano zinc oxide, forming spherical particles. The spherical particles are added to a calcium chloride aqueous solution, and the resulting mixture is subjected to a cross-linking reaction at room temperature for 1 to 3 hours. The reaction is then stopped, and the resulting reactants are freeze-dried under vacuum to a constant weight to obtain the hydrophobic antibacterial particles.

3. The method according to claim 2, characterized in that, Step a) involves the preparation of Artemisia argyi extract, including the following operations: The dried mugwort is soaked in a 60-70 wt% ethanol aqueous solution at a temperature of 60-70℃ for 30-60 minutes. After soaking, it is filtered, and the resulting filtrate is the mugwort extract. In the preparation of the mugwort extract, the amount of dried mugwort and 60-70 wt% ethanol aqueous solution added is: 5-10 parts by weight of dried mugwort and 40-90 parts by weight of 60-70 wt% ethanol aqueous solution.

4. The method according to claim 2, characterized in that, In step a), the amounts of zinc acetate dihydrate, deionized water, ammonia, and Artemisia argyi extract added are: 4-9 parts by weight of zinc acetate dihydrate, 20-40 parts by weight of deionized water, 2-5 parts by weight of ammonia, and 1-10 parts by weight of Artemisia argyi extract.

5. The method according to claim 2, characterized in that: In step b), the amounts of modified nano zinc oxide, ethanol, silane coupling agent, and deionized water added are: 1-2 parts by weight of modified nano zinc oxide, 30-60 parts by weight of ethanol, 5-20 parts by weight of silane coupling agent, and 10-20 parts by weight of deionized water.

6. The method according to claim 2, characterized in that: In step c), the isocyanate is any one of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, polymethylene polyphenyl polyisocyanate, and hexamethylene diisocyanate; the polyetheramine is any one of polyetheramine D2000, polyetheramine ED900, and polyetheramine D230; the hydrophilic chain extender is any one of 2,2-bis(hydroxymethyl)butyric acid, dimethylolpropionic acid, and dihydroxysulfonate; the polylysine is any one of ε-polylysine and α-polylysine; the crosslinking agent is any one of trimethylolpropane, 1,2-propylene glycol, and ethylene glycol; and the neutralizing agent is any one of triethylamine, dimethylethanolamine, and ammonia.

7. The method according to claim 2, characterized in that: In step c), the amounts of isocyanate, polyetheramine, hydrophilic chain extender, polylysine, crosslinking agent, neutralizing agent, and deionized water added are: 3.5–7 parts by weight of isocyanate, 10.5–21 parts by weight of polyetheramine, 0.28–0.56 parts by weight of hydrophilic chain extender, 0.1–0.28 parts by weight of polylysine, 0.14–0.28 parts by weight of crosslinking agent, 0.38–0.4 parts by weight of neutralizing agent, and 20–40 parts by weight of deionized water; in step d), the mass concentration of the obtained sodium alginate-gelatin solution is 2%–6%; in step e), the amounts of polylysine-modified polyurea emulsion and sodium alginate-gelatin solution added to the composite emulsion are: 0.09–0.12 parts by weight of polylysine-modified polyurea emulsion and 15–20 parts by weight of sodium alginate-gelatin solution.

8. The method according to claim 2, characterized in that: In step f), the amount of Artemisia argyi-coupled modified nano zinc oxide and calcium chloride aqueous solution added is: 0.2 to 0.4 parts by mass of Artemisia argyi-coupled modified nano zinc oxide and 20 to 40 parts by mass of calcium chloride aqueous solution, wherein the mass concentration of calcium chloride aqueous solution is 2.5 to 5%.

9. A stone-like paint containing the hydrophobic antibacterial particles of claim 1, characterized in that, It has the following composition and proportions: Resin: 10-30 parts by weight; Colored sand: 50-70 parts by weight; Hydrophobic antibacterial granules: 0.1–5 parts by weight; Titanium dioxide: 5-15 parts by weight; Thickener: 0.2–0.5 parts by weight; Defoamer: 0.1–0.3 parts by weight; Wetting and dispersing agent: 0.2–0.6 parts by weight; Film-forming aid: 0.2 to 0.5 parts by weight.

10. A method for preparing the real stone paint according to claim 9, characterized in that, The process includes the following steps: while stirring, colored sand, hydrophobic antibacterial particles, titanium dioxide, thickener, defoamer, wetting and dispersing agent, and film-forming aid are added sequentially to the resin in the specified proportions, and the mixture is stirred until homogeneous to obtain the real stone paint.

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