Aluminum-based mineral composite antibacterial material and its preparation method and application

Abstract

The present invention provides an aluminum-based mineral composite antibacterial material and its preparation method and application. The preparation method comprises S1, uniformly dispersing a certain amount of kaolin and Zn(NO3)2·6H2O in deionized water and stirring to form a stable suspension for later use; S2, weighing a certain amount of NaOH and dissolving it in deionized water, then adding the NaOH solution dropwise to the suspension in S1 using a separatory funnel. After the addition is completed, stirring, centrifuging, washing, and drying to obtain a dried product; S3, roasting the dried product at a certain heating rate and a certain temperature, wherein the heating rate is 5°C / min, the roasting temperature is 250°C to 400°C, and the roasting time is 2 to 6 hours to obtain a roasted product, which is then ground to obtain an aluminum-based mineral composite antibacterial material. The antibacterial rate of the prepared antibacterial material is greater than 99% as tested by the Antibacterial Materials Testing Center of the Institute of Physics and Chemistry, Chinese Academy of Sciences, meeting the national Class I antibacterial standard; the antibacterial coating prepared has an antibacterial rate greater than 99%, and the patented coating of the present invention has passed the quality inspection of the National Coating Quality Inspection and Testing Center.

Description

Technical Field

[0001] The present invention relates to the technical field of antibacterial materials, and in particular to an aluminum-based mineral composite antibacterial material and a preparation method and application thereof. Background Art

[0002] Aluminum-based minerals are primarily aluminum silicate minerals with relatively high aluminum content, primarily clay minerals (such as kaolin, bentonite, diatomaceous earth, vermiculite, attapulgite, kaolinite, montmorillonite, halloysite, sepiolite, black talc, and illite). Due to their abundant reserves, low cost, potential biosafety, and other excellent physical and chemical properties, they are widely used in petrochemicals, building materials, environmental protection, metallurgy, biomedicine, agriculture, and animal husbandry.

[0003] Today, infectious diseases and drug resistance of pathogens seriously threaten public health around the world. Therefore, the research, development and production of materials and products with antibacterial functions are of great significance to social production and people's lives. The promotion and application of antibacterial products is bound to set off a new revolution in the health industry.

[0004] Currently, antimicrobial materials on the market are divided into three main categories: organic, natural, and inorganic. Most organic antimicrobial materials are toxic, have poor safety, low heat resistance, are susceptible to hydrolysis, and have a short shelf life, limiting their widespread use. Natural antimicrobial materials, while highly effective, are difficult to process and have a short shelf life. Inorganic antimicrobial materials are based on inorganic materials, combined with antimicrobial ions, oxides, or photocatalytic materials such as silver, copper, and zinc transition metals. They offer stable antimicrobial efficacy, excellent heat resistance, broad antimicrobial spectrum, and a long duration of inhibition. However, the widespread application of inorganic antimicrobial agents currently on the market is hampered by their high cost, high price, and tendency to agglomerate during use.

[0005] In addition, antimicrobial materials for environmental use are also gaining more and more attention, and the demand for antimicrobial coatings is showing a clear growth trend. This demand is not only reflected in the field of environmental construction, but also in many other fields such as medical care, food, steel, furniture, and household appliances. When antimicrobial coatings are used in public places, they can reduce the number of bacteria in public places and reduce the chance of cross-infection and contact infection; when used in home environments, they can effectively reduce the density of bacteria on furniture and other items, optimizing people's living environment. Antimicrobial coatings have both good decorative functions and excellent antimicrobial properties. However, antimicrobial coatings currently have problems and defects such as more complex preparation processes than ordinary coatings, environmental safety, and high costs for commercial and industrial applications. Therefore, how to simultaneously take into account the strong antimicrobial properties, safety, and stability of antimicrobial coatings while having low production costs and simple process routes is an urgent problem to be solved in the current research process of antimicrobial coatings.

[0006] Chinese patent CN114158569A discloses a black talc-based antibacterial agent and its preparation method and application. It comprises reacting a certain amount of activated black talc, zinc nitrate hexahydrate, and sodium hydroxide in an ethanol solution system and then calcining to prepare a zinc oxide / black talc binary composite antibacterial agent, and then preparing a silver-zinc oxide / black talc ternary composite antibacterial agent on this basis. This technology has many disadvantages: (1) it has many raw materials and a complicated process. The raw material black talc needs to be calcined at a high temperature of 700°C, which consumes a lot of energy; (2) it needs to react in an ethanol solution system, which is not conducive to industrial large-scale preparation; (3) AgNO3 is introduced on the basis of the binary antibacterial material, which is complicated and has a high cost; (4) the antibacterial coating prepared by this patent has defects. No thickener is added to the formula. This firstly leads to low viscosity of the coating and sagging during construction; secondly, it causes the dispersed particles of the coating to precipitate during storage, resulting in thinning and stratification, which is not conducive to the long-term storage and use of the coating. Therefore, there is an urgent need to develop and design an aluminum-based mineral antibacterial material with simple process, low cost, strong antibacterial and environmental friendliness to promote the widespread application of aluminum-based mineral composite materials. Summary of the Invention

[0007] The purpose of the present invention is to address the above-mentioned deficiencies in the prior art and to provide an aluminum-based mineral composite antibacterial material and a preparation method and application thereof.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] The first object of the present invention is to provide a method for preparing an aluminum-based mineral composite antibacterial material, comprising the following specific steps:

[0010] S1. Evenly disperse a certain amount of kaolin and Zn(NO3)2·6H2O in deionized water and stir to form a stable suspension for later use; the kaolin is composed of flaky kaolinite and tubular halloysite, with a particle size of 400-800 mesh; the mass volume ratio of the kaolin, Zn(NO3)2·6H2O and deionized water is (0.3-6) g:1 g:90 mL;

[0011] S2. Weigh a certain amount of NaOH and dissolve it in deionized water. Then, add the NaOH solution dropwise to the suspension in S1 using a separatory funnel. After the addition is completed, continue stirring for a certain period of time, then centrifuge and wash, and dry to obtain a dry product; the stirring time is 30 to 60 minutes, the centrifugal speed is 5000 to 10000 r / min, the centrifugal time is 3 to 10 minutes, and the drying temperature is 40 to 80°C;

[0012] S3. The dried product is calcined at a certain heating rate and temperature, wherein the heating rate is 5°C / min, the calcination temperature is 250°C to 400°C, and the calcination time is 2 to 6 hours to obtain a calcined product, which is ground to obtain an aluminum-based mineral composite antibacterial material.

[0013] Furthermore, the content of Fe2O3 in the chemical composition of the kaolin is not higher than 0.3%, and the content of Al2O3 is not lower than 36.5%;

[0014] Furthermore, the calcination temperature is 350°C ± 10°C, and the calcination time is 2 to 4 hours.

[0015] Furthermore, the aluminum mineral composite antibacterial material is a ZnO / kaolin composite antibacterial material;

[0016] The second object of the present invention is to provide an aluminum-based mineral composite antibacterial material prepared by the above-mentioned preparation method.

[0017] Furthermore, the nano ZnO loading in the ZnO / kaolin composite antibacterial material is not less than 15%.

[0018] Furthermore, the particle size D of the ZnO / kaolin composite antibacterial material is 90 10~13μm, D 50 4~5μm, D 10 1~1.5μm.

[0019] The third object of the present invention is to provide an antibacterial coating comprising the above-mentioned aluminum-based mineral composite antibacterial material.

[0020] Furthermore, the antibacterial coating comprises the following raw materials in parts by weight, calculated by weight percentage:

[0021] Component 1: 15-35 parts of titanium dioxide and 5-20 parts of aluminum-based mineral composite antibacterial material.

[0022] Component 2: 0.1-1.5 parts of leveling agent, 0.1-1 parts of wetting agent, 0.1-1.5 parts of dispersant, 0.1-1.5 parts of defoaming agent, 0.1-1.5 parts of pH regulator, 0.1-0.3g of aqueous bentonite, 0.1-0.5g of thickener, and 10-18 parts of water.

[0023] Component three: including 40-80 parts of epoxy resin and 0.2-1 part of anti-flash rust additive.

[0024] Component 4: 10 to 40 parts of curing agent.

[0025] A fourth object of the present invention is to provide a method for preparing the above-mentioned antibacterial coating. First, component one and component two are weighed according to a ratio, mixed and stirred at room temperature to disperse, and a uniform slurry is obtained after dispersion for a certain time. Component three is then added and stirred and dispersed for a certain time to obtain an antibacterial coating. Finally, component four is added and stirred until uniform before spraying for use.

[0026] Furthermore, component one and component two are dispersed at 1500-2500 r / min for 1 hour using a high-speed disperser, and after adding component three, they are stirred at 450-1000 r / min for 0.5-1 hour to obtain an antibacterial coating. After adding component four, the mixture is stirred at a low speed and can be sprayed for use.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) The present invention provides an aluminum-based mineral composite antibacterial material and its preparation method and application. This material fully utilizes the structure and physical properties of natural aluminum-based mineral kaolin composed of flaky kaolinite and tubular halloysite, adopts a liquid phase precipitation method, and is prepared by functional assembly and in-situ synthesis of nano zinc oxide to obtain an aluminum-based mineral kaolin composite antibacterial material. This solves the problem of zinc oxide being easily agglomerated when used alone, and is more conducive to the release of active oxygen. According to the Antibacterial Material Testing Center of the Institute of Physics and Chemistry of the Chinese Academy of Sciences, the antibacterial rate is greater than 99%, meeting the national Class I antibacterial standard.

[0029] (2) The present invention uses kaolin, a natural aluminum-based mineral with abundant reserves and low cost, as an antibacterial carrier. It has potential biosafety. Using it as a carrier to construct a composite antibacterial material can effectively solve the problem of environmental safety.

[0030] (3) The antibacterial coating provided by the present invention has a simple preparation process, low cost, and excellent antibacterial performance. According to the test results of the Antibacterial Materials Testing Center of the Institute of Physics and Chemistry of the Chinese Academy of Sciences, the antibacterial rate of the antibacterial coating is greater than 99%, which is conducive to industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a scanning electron microscope image of kaolin;

[0032] Figure 2 is the X-ray diffraction pattern of kaolin;

[0033] Figure 3 This is a scanning electron microscope image of nano-ZnO prepared without adding kaolin;

[0034] Figure 4 This is a scanning electron microscope image of the ZnO / kaolin composite antibacterial material;

[0035] Figure 5This is the antibacterial effect diagram of ZnO / kaolin composite antibacterial materials with different loading amounts on Staphylococcus aureus (S. aureus);

[0036] Figure 6 This is the antibacterial effect diagram of ZnO / kaolin composite antibacterial materials with different loading amounts on Escherichia coli (E.coli);

[0037] Figure 7a This is a biological scanning electron microscope image of normal Staphylococcus aureus;

[0038] Figure 7b This is a biological scanning electron microscope image of Staphylococcus aureus after interacting with the ZnO / kaolin composite antibacterial material;

[0039] Figure 8a This is a biological scanning electron microscope image of normal Escherichia coli;

[0040] Figure 8b This is a biological scanning electron micrograph of Escherichia coli after reacting with the ZnO / kaolin composite antibacterial material;

[0041] Figure 9 This is the X-ray diffraction pattern of ZnO / kaolin composite antibacterial material.

[0042] Figure 10 This is the particle size diagram of ZnO / kaolin composite antibacterial material. DETAILED DESCRIPTION

[0043] To make the purpose, technical solutions and advantages of the present invention clearer, the specific embodiments of the present invention are described in further detail below in conjunction with specific examples and accompanying drawings. Where specific techniques or conditions are not specified in the examples, the techniques or conditions described in the literature in this field or the product specifications are used. Where the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be obtained commercially.

[0044] The particle size of the kaolin powder used in the present invention is 400-800 mesh, and its chemical composition analysis is shown in Table 1:

[0045] Table 1.

[0046] Components <![CDATA[SiO2]]> <![CDATA[Al2O3]]> <![CDATA[K2O]]> MgO <![CDATA[Fe2O3]]> Content (wt.%) 48.32 37.01 1.96 0.366 0.278 Components <![CDATA[P2O5]]> <![CDATA[Na2O]]> CaO <![CDATA[TiO2]]> LOI. Content (wt.%) 0.201 0.091 0.0666 0.0065 11.44

[0047] Its chemical composition is mainly SiO2 and Al2O3, with contents of 48.32% and 37.01% respectively; the K2O content is 1.96%, followed by MgO content of 0.366% and Fe2O content of 0.278%. Studies have shown that iron-containing minerals have certain bactericidal abilities. In theory, kaolin itself also has a certain antibacterial effect. However, during the experiment, the applicant found that due to its low Fe2O3 content, the antibacterial effect of pure kaolin is not obvious and can be ignored.

[0048] Example 1

[0049] In this embodiment, an aluminum-based mineral composite antibacterial material with a ZnO loading of 5% is prepared.

[0050] 5.198 g of uniform kaolin powder and 1 g of Zn(NO₃)₂·6H₂O were uniformly dispersed in 90 mL of deionized water and magnetically stirred at room temperature for 30 minutes to form a stable suspension. 0.34 g of granular NaOH was weighed and dissolved in 250 mL of deionized water. The NaOH solution was then added dropwise to the suspension using a separatory funnel. After the addition was complete, the suspension was stirred for an additional 45 minutes. The mixture was then centrifuged at 8000 rpm until the pH reached neutral, dried, and ground. Finally, the dried and ground product was calcined in a muffle furnace at 350°C for 4 hours at a heating rate of 5°C / min. After calcination, the product was removed and ground to obtain an aluminum-based mineral composite antibacterial material with a ZnO loading of 5%.

[0051] Example 2

[0052] In this embodiment, an aluminum-based mineral composite antibacterial material with a ZnO loading of 15% is prepared.

[0053] 1.550g of uniform powdered kaolin and 1g of Zn(NO3)2·6H2O were uniformly dispersed in 90mL of deionized water and magnetically stirred at room temperature for 30 minutes to form a stable suspension. 0.34g of granular NaOH was weighed and dissolved in 250mL of deionized water. The NaOH solution was then added dropwise to the suspension using a separatory funnel. After the addition was complete, the suspension was stirred for an additional 45 minutes. The mixture was then centrifuged at 8000 rpm until the pH was neutral, dried, and ground. Finally, the dried and ground product was calcined in a muffle furnace at 350°C for 4 hours at a heating rate of 5°C / min. After calcination, the calcined product was removed and ground to obtain an aluminum-based mineral composite antibacterial material with a ZnO loading of 15%.

[0054] The chemical composition of the aluminum-based mineral composite antibacterial material loaded with 15% ZnO prepared in this example is shown in Table 2.

[0055] Table 2.

[0056] Components <![CDATA[SiO2]]> <![CDATA[Al2O3]]> ZnO <![CDATA[K2O]]> <![CDATA[Na2O]]> Content (wt%) 45.17 36.11 15.13 2.04 0.596 Components MgO <![CDATA[Fe2O3]]> <![CDATA[P2O5]]> CaO <![CDATA[TiO2]]> Content (wt%) 0.236 0.252 0.152 0.0757 0.0061

[0057] Example 3

[0058] In this embodiment, an aluminum-based mineral composite antibacterial material with a ZnO loading of 30% is prepared.

[0059] 0.638g of uniform powdered kaolin and 1g of Zn(NO3)2·6H2O were uniformly dispersed in 90mL of deionized water and magnetically stirred at room temperature for 30 minutes to form a stable suspension for later use. 0.34g of granular NaOH was weighed and dissolved in 250mL of deionized water. The NaOH solution was then added dropwise to the suspension using a separatory funnel. After the addition was complete, the suspension was stirred for an additional 45 minutes. The mixture was then centrifuged at 8000 rpm until the pH was neutral, dried, and ground. Finally, the dried and ground product was calcined in a muffle furnace at 350°C for 4 hours at a heating rate of 5°C / min. After calcination, the calcined product was removed and ground to obtain an aluminum-based mineral composite antibacterial material with a ZnO loading of 30%.

[0060] Example 4

[0061] In this embodiment, an aluminum-based mineral composite antibacterial material with a ZnO loading of 45% is prepared.

[0062] 0.334g of uniform powdered kaolin and 1g of Zn(NO3)2·6H2O were uniformly dispersed in 90mL of deionized water and magnetically stirred at room temperature for 30 minutes to form a stable suspension for later use. 0.34g of granular NaOH was weighed and dissolved in 250mL of deionized water. The NaOH solution was then added dropwise to the suspension using a separatory funnel. After the addition was complete, the suspension was stirred for an additional 45 minutes. The mixture was then centrifuged at 8000 rpm until the pH was neutral, dried, and ground. Finally, the dried and ground product was calcined in a muffle furnace at 350°C for 4 hours at a heating rate of 5°C / min. After calcination, the calcined product was removed and ground to obtain an aluminum-based mineral composite antibacterial material with a ZnO loading of 45%.

[0063] Comparative Example 1

[0064] In this embodiment, nano zinc oxide was prepared without adding kaolin.

[0065] Take 1g Zn(NO3)2·6H2O and evenly disperse it in 90mL deionized water. Stir it magnetically at room temperature for 30 minutes to form a stable suspension for later use. Weigh 0.34g granular NaOH and dissolve it in 250mL deionized water. Then, add the NaOH solution dropwise to the suspension using a separatory funnel. After the addition is completed, stir for another 45 minutes. Then, centrifuge at 8000r / min until the pH is neutral, dry and grind it, and finally place the dried and ground product in a muffle furnace at 350℃ for 4h at a heating rate of 5℃ / min. After the calcination is completed, take out the calcined product and grind it to obtain nano zinc oxide.

[0066] Example 5

[0067] In this embodiment, a kaolin water-based antibacterial coating with an aluminum-based mineral composite antibacterial material addition amount of 1% is prepared.

[0068] Add 34g titanium dioxide, 1g aluminum mineral composite antibacterial material, 0.2g leveling agent, 0.3g wetting agent, 0.5g dispersant, 0.5g defoaming agent, 0.5g pH adjuster, 0.2g water-based bentonite, 0.3g thickener and 12g water into the paint bucket, use a digital display disperser to disperse at a high speed of 2000r / min for 1h to obtain a uniform slurry, then add 50g epoxy resin and 0.5g anti-flash rust additive and stir at a low speed of 600r / min for 0.25h. Mix well to obtain kaolin water-based antibacterial coating. Add 10g curing agent during high-pressure spraying and stir evenly before use.

[0069] Example 6

[0070] In this embodiment, a kaolin water-based antibacterial coating with an aluminum-based mineral composite antibacterial material addition amount of 3% is prepared.

[0071] Add 32g titanium dioxide, 3g aluminum mineral composite antibacterial material, 0.2g leveling agent, 0.3g wetting agent, 0.5g dispersant, 0.5g defoaming agent, 0.5g pH adjuster, 0.2g water-based bentonite, 0.3g thickener and 12g water into the paint bucket, use a digital display disperser to disperse at a high speed of 2000r / min for 1h to obtain a uniform slurry, then add 50g epoxy resin and 0.5g anti-flash rust additive and stir at a low speed of 600r / min for 0.25h. Mix well to obtain kaolin water-based antibacterial coating. Add 10g curing agent during high-pressure spraying and stir evenly before use.

[0072] Example 7

[0073] In this embodiment, a kaolin water-based antibacterial coating with an addition amount of 5% of aluminum-based minerals and antibacterial materials is prepared.

[0074] Add 30g titanium dioxide, 5g aluminum mineral composite antibacterial material, 0.2g leveling agent, 0.3g wetting agent, 0.5g dispersant, 0.5g defoaming agent, 0.5g pH adjuster, 0.2g water-based bentonite, 0.3g thickener and 12g water into the paint bucket, use a digital display disperser to disperse at a high speed of 2000r / min for 1h to obtain a uniform slurry, then add 50g epoxy resin and 0.5g anti-flash rust additive and stir at a low speed of 600r / min for 0.25h. Mix well to obtain kaolin water-based antibacterial coating. Add 10g curing agent during high-pressure spraying and stir evenly before use.

[0075] Example 8

[0076] In this embodiment, a kaolin water-based antibacterial coating with an aluminum-based mineral composite antibacterial material addition amount of 7% is prepared.

[0077] Add 28g titanium dioxide, 7g aluminum mineral composite antibacterial material, 0.2g leveling agent, 0.3g wetting agent, 0.5g dispersant, 0.5g defoaming agent, 0.5g pH adjuster, 0.2g water-based bentonite, 0.3g thickener and 12g water into the paint bucket, use a digital display disperser to disperse at a high speed of 2000r / min for 1h to obtain a uniform slurry, then add 50g epoxy resin and 0.5g anti-flash rust additive and stir at a low speed of 600r / min for 0.25h. Mix well to obtain kaolin water-based antibacterial coating. Add 10g curing agent during high-pressure spraying and stir evenly before use.

[0078] Example 9

[0079] In this embodiment, a kaolin water-based antibacterial coating with an aluminum-based mineral composite antibacterial material addition amount of 9% is prepared.

[0080] Add 26g titanium dioxide, 9g aluminum mineral composite antibacterial material, 0.2g leveling agent, 0.3g wetting agent, 0.5g dispersant, 0.5g defoaming agent, 0.5g pH regulator, 0.2g water-based bentonite, 0.3g thickener, and 12g water into a paint bucket, and use a digital display disperser to disperse at a high speed of 2000r / min for 1h to obtain a uniform slurry. Then add 50g epoxy resin and 0.5g anti-flash rust additive and stir at a low speed of 600r / min for 0.25h. Mix evenly to obtain kaolin water-based antibacterial coating. Add 10g curing agent during high-pressure spraying and stir evenly before use.

[0081] Escherichia coli (E. coli) antibacterial test

[0082] In this embodiment, ZnO / aluminum mineral kaolin composite antibacterial material (ZnO loading amounts are 5%, 15%, 30%, and 45%, respectively) is used to conduct an antibacterial experiment on Escherichia coli (E. coli).

[0083] Bacterial activation: Take out the stored Escherichia coli (E. coli) from the 4°C refrigerator and place it in a microbiological safety cabinet. Use an inoculating loop to pick up a colony and add it to 5 mL of liquid culture medium. Incubate it on a constant temperature shaker for 12 hours at a speed of 180 rpm and a temperature of 37°C.

[0084] Dilution of bacterial solution (E. coli): Take out the bacterial solution that has been revived for 12 hours and mark it as No. 0. Then take the required four 1.5mL sterile centrifuge tubes and mark them as No. 1, No. 2, No. 3, and No. 4 respectively. Add 900μL of LB liquid culture medium to sterile centrifuge tube No. 1. Take 100μL of the activated bacterial solution for 12 hours and transfer it to a 1.5mL centrifuge tube. After mixing evenly with a pipette, take out 100μL and transfer it to centrifuge tube No. 2 and continue mixing evenly. Perform gradient dilution. Dilute it to centrifuge tube No. 4 in the same way. The dilution multiple is 10,000 times.

[0085] Adding Antimicrobial Materials: Prepare the required 50mL sterile centrifuge tubes and label them one by one. Except for the control tube, which does not contain any antimicrobial materials but only contains 10mL of LB broth. Each of the remaining tubes contains 10mg of 5% ZnO / kaolin composite antimicrobial material, 10mg of 15% ZnO / kaolin composite antimicrobial material, 10mg of 30% ZnO / kaolin composite antimicrobial material, or 10mg of 45% ZnO / kaolin composite antimicrobial material, along with 10mL of LB broth, to serve as the experimental groups for analysis. Then, take 100μL of the 10,000-fold diluted bacterial solution and add it to each of the control and experimental tubes. Incubate the tubes at 37°C in a shaker at 180 rpm for 4 hours.

[0086] Plate Spreading: Sterilize the prepared culture dishes and place them in a safety cabinet. Label them and drop 50 μL of the control and experimental bacterial cultures, which have been incubated for 4 hours, into each dish. Add 4 sterile glass beads to each dish and roll for 2 minutes in each direction. Spread three dishes per sample as a parallel group. Finally, place the coated dishes in a constant temperature incubator and incubate for 15 hours at 37°C.

[0087] Plate counting and photographing: Calculate the antibacterial rates of different kaolin samples and compare their antibacterial properties.

[0088] The above antibacterial experiments were all carried out in the biosafety cabinet of the microbiology laboratory.

[0089] Staphylococcus aureus (S. aureus) antibacterial test

[0090] In this embodiment, an antibacterial experiment on Staphylococcus aureus (S. aureus) was conducted using a ZnO / aluminum mineral kaolin composite antibacterial material (ZnO loading amounts were 5%, 15%, 30%, and 45%, respectively).

[0091] Bacterial activation: Take out the preserved Staphylococcus aureus from the 4°C refrigerator and place it in a microbiological safety cabinet. Use an inoculation loop to pick up a colony and add it to 5 mL of liquid culture medium. Incubate it in a constant temperature shaker for 12 hours at a speed of 180 rpm and a temperature of 37°C.

[0092] Dilution of bacterial solution (S. aureus): Take out the bacterial solution that has been revived for 12 hours and mark it as No. 0. Then take the required four 1.5 mL sterile centrifuge tubes and mark them as No. 1, No. 2, No. 3, and No. 4 respectively. Add 900 μL of LB liquid culture medium to sterile centrifuge tube No. 1. Take 100 μL of the activated bacterial solution for 12 hours and transfer it to a 1.5 mL centrifuge tube. After mixing evenly with a pipette, take out 100 μL and transfer it to centrifuge tube No. 2 and continue mixing evenly. Perform gradient dilution. Dilute it to centrifuge tube No. 4 in the same way. The dilution multiple is 10,000 times.

[0093] Material Addition: Prepare the required 50mL sterile centrifuge tubes and label them one by one. Except for the control tube, which does not contain any antimicrobial material but only contains 10mL of LB culture medium, add 10mg of 5% ZnO / kaolin composite antimicrobial material, 10mg of 15% ZnO / kaolin composite antimicrobial material, 10mg of 30% ZnO / kaolin composite antimicrobial material, or 10mg of 45% ZnO / kaolin composite antimicrobial material and 10mL of LB culture medium to each of the remaining tubes for analysis as the experimental groups. Then, take 100μL of the 10,000-fold diluted bacterial solution and add it to each of the control and experimental tubes. Place in a 37°C incubator at 180 rpm for 4 hours.

[0094] Plate Spreading: Sterilize the prepared culture dishes and place them in a safety cabinet. Label them and drop 50 μL of the control and experimental bacterial cultures, which have been incubated for 4 hours, into each dish. Add 4 sterile glass beads to each dish and roll for 2 minutes in each direction. Spread three dishes per sample as a parallel group. Finally, place the coated dishes in a constant temperature incubator and incubate for 15 hours at 37°C.

[0095] Plate counting and photographing: Calculate the antibacterial rates of different kaolin samples and compare their antibacterial properties.

[0096] The above antibacterial experiments were all carried out in the biosafety cabinet of the microbiology laboratory.

[0097] Figure 1 This is a scanning electron microscope image of kaolin. It clearly shows the morphology of the kaolin, which is flaky and tubular. The flaks are uneven in size, with irregular edges. The aggregates are stacked or vermicular, lacking an orderly, oriented arrangement and instead appearing chaotically packed together. Combined with XRD, the flaky material is kaolinite, while the tubular material is halloysite.

[0098] Figure 2 This is the X-ray diffraction pattern of kaolin. It can be seen from the figure that the main phases in this kaolin are kaolinite, halloysite, quartz and muscovite.

[0099] Figure 3 This is a scanning electron microscope image of nano-ZnO prepared without adding kaolin. As can be seen from the figure, the morphology of nano-ZnO is mainly spherical, and the self-agglomeration phenomenon is very serious.

[0100] Figure 4 This is a scanning electron micrograph of the ZnO / kaolin antibacterial composite material. As can be seen from the image, the ZnO is relatively evenly loaded on the surface of the kaolin, indicating that the ZnO / kaolin antibacterial composite material prepared by the present invention has no particle agglomeration, thus resolving the problem of nano-ZnO agglomeration when used alone.

[0101] Figure 5 Figures a through e show the antibacterial effects of the control, 5% ZnO / kaolin, 15% ZnO / kaolin, 30% ZnO / kaolin, and 45% ZnO / kaolin-based antibacterial materials against Staphylococcus aureus (S. aureus), respectively. The figures show that increasing ZnO loading increases the antibacterial effect. At a loading of 15%, the antibacterial rate exceeds 99%, meeting the national Class I antibacterial standard.

[0102] Figure 6 Figures f through j show the antibacterial effects of the control, 5% ZnO / kaolin, 15% ZnO / kaolin, 30% ZnO / kaolin, and 45% ZnO / kaolin-based antibacterial materials against Escherichia coli (E. coli). The figures show that the antibacterial effect improves with increasing ZnO loading. At a loading of 15%, the antibacterial rate exceeds 99%, meeting the national Class I antibacterial standard.

[0103] Figure 7a This is a scanning electron micrograph of a normal Staphylococcus aureus. It can be seen that normal Staphylococcus aureus has a complete morphological structure, a spherical body, and a smooth outer surface.

[0104] Figure 7b This is a biological scanning electron microscope image of Staphylococcus aureus after the ZnO / kaolin composite antibacterial material reacts with it. It can be seen that after the ZnO / kaolin composite antibacterial material reacts with Staphylococcus aureus, it coats the surface of the bacteria, causing the Staphylococcus aureus to deform, with wrinkles on the surface and the bacterial structure destroyed. Figure 5 As can be seen from the antibacterial experiment effect diagram, Staphylococcus aureus was killed.

[0105] Figure 8aThis is a scanning electron micrograph of a normal E. coli. It can be seen that normal E. coli has a rod-like morphology with blunt ends.

[0106] Figure 8b This is a biological scanning electron microscope image of Escherichia coli after the reaction with ZnO / kaolin composite antibacterial material. It can be seen that the aluminum mineral composite antibacterial material is in close contact with Escherichia coli, causing Escherichia coli to deform and shrink. Figure 6 Antibacterial experiment effect picture, E. coli has been killed.

[0107] Figure 9 This is the X-ray diffraction pattern of the ZnO / kaolin composite antibacterial material. As can be seen from the figure, the main phases in the kaolin are zinc oxide, kaolinite, halloysite, quartz and muscovite.

[0108] Figure 10 This is a particle size diagram for the ZnO / kaolin antibacterial composite material. The position and shape of the curve indicate that the particle size is small and relatively uniform, with a relatively smooth overall interval. This demonstrates that the ZnO / kaolin antibacterial composite material prepared by the present invention exhibits no particle agglomeration and exhibits a high degree of micro-homogenization, resolving the problem of agglomeration of nano-ZnO when used alone.

[0109] Any matters not mentioned above shall be subject to the existing technology.

[0110] Although some specific embodiments of the present invention have been described in detail through examples, those skilled in the art should understand that the above examples are for illustration only and are not intended to limit the scope of the present invention. Those skilled in the art of the present invention may make various modifications or additions to the described specific embodiments or replace them in similar ways, but they will not deviate from the direction of the present invention or exceed the scope defined by the appended claims. Those skilled in the art should understand that any modifications, equivalent replacements, improvements, etc. made to the above embodiments based on the technical essence of the present invention should be included in the scope of protection of the present invention.

Claims

1. An aluminum-based mineral composite antibacterial material, characterized in that: The particle size D of the composite antibacterial material 90 10~13μm, D 50 4~5μm, D 10 The thickness of the composite antibacterial material is 1-1.5 μm, and the preparation method of the composite antibacterial material comprises the following specific steps: S1. Evenly dispersing a certain amount of kaolin and Zn(NO3)2·6H2O in deionized water and stirring to form a stable suspension for later use; the kaolin is composed of flaky kaolinite and tubular halloysite, with a particle size of 400-800 mesh; the mass volume ratio of the kaolin, Zn(NO3)2·6H2O, and deionized water is (0.3-6) g:1 g:90 mL; the chemical composition of the kaolin is 48.32% SiO2 and 37.01% Al2O3; S2. Weigh a certain amount of NaOH and dissolve it in deionized water. Then, add the NaOH solution dropwise to the suspension in S1 using a separatory funnel. After the addition is completed, continue stirring for a certain period of time, and then centrifuge and dry to obtain a dry product; the stirring time is 30 to 60 minutes, the centrifugal speed is 5000 to 10000 r / min, the centrifugal time is 3 to 10 minutes, and the drying temperature is 40 to 80°C; S3. The dried product is calcined at a certain heating rate and a certain temperature, wherein the heating rate is 5 ° C / min, the calcination temperature is 350 ° C ± 10 ° C, and the calcination time is 4 h to obtain a calcined product, which is ground to obtain an aluminum-based mineral composite antibacterial material.

2. The aluminum-based mineral composite antibacterial material according to claim 1, wherein: The nano ZnO loading amount in the aluminum-based mineral composite antibacterial material is not less than 15%.

3. An antibacterial coating, characterized in that: The invention comprises the aluminum-based mineral composite antibacterial material according to claim 2.

4. The antibacterial coating according to claim 3, wherein The antibacterial coating comprises the following raw materials in parts by weight, calculated by weight percentage: Component 1: 15-35 parts of titanium dioxide, 5-20 parts of aluminum mineral composite antibacterial material; Component 2: 0.1-1.5 parts of leveling agent, 0.1-1 parts of wetting agent, 0.1-1.5 parts of dispersant, 0.1-1.5 parts of defoaming agent, 0.1-1.5 parts of pH regulator, 0.1-0.3 g of aqueous bentonite, 0.1-0.5 g of thickener, and 10-18 parts of water; Component 3: including 40-80 parts of epoxy resin and 0.2-1 parts of anti-flash rust additive; Component 4: 10~40 parts of curing agent.

5. A method for preparing the antibacterial coating according to claim 4, characterized in that: First, weigh component one and component two according to the ratio, mix and disperse them at room temperature, and obtain a uniform slurry after dispersing for a certain time. Then add component three, stir and disperse for a certain time to obtain an antibacterial coating, and finally add component four, stir until uniform, and then spray for use.

6. The method for preparing the antibacterial coating according to claim 5, wherein: Components one and two are dispersed in a high-speed disperser at 1500-2500 r / min for 1 hour. After adding component three, stir at 450-1000 r / min for 0.5-1 hour to obtain the antibacterial coating. After adding component four, stir at low speed until evenly mixed and then spray for use.

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