Preparation method of nano-zinc oxide composite silver ion antibacterial agent

Abstract

The application belongs to the technical field of antibacterial agents, and particularly relates to a preparation method of a nano zinc oxide composite silver ion antibacterial agent, which comprises the following steps: one, synthesizing nano zinc oxide by adopting a sol-gel method; two, loading silver ions to sodium zirconium phosphate by adopting an ion exchange method to obtain silver-loaded sodium zirconium phosphate; three, compounding the nano zinc oxide and the silver-loaded sodium zirconium phosphate by adopting a liquid phase method to obtain the nano zinc oxide composite silver ion antibacterial agent.In the application, there are differences in the bacteriostatic mechanisms of zinc oxide and silver ions, and there is a synergistic bacteriostatic mechanism in the composite use, so that the obtained composite antibacterial agent has more excellent antibacterial performance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of antibacterial agents, and particularly relates to a preparation method of a nano zinc oxide composite silver ion antibacterial agent. BACKGROUND

[0002] Antibacterial agents are a kind of agents for preventing and treating pathogenic microorganisms such as bacteria and fungi. Antibacterial agents can be divided into natural antibacterial agents and artificial antibacterial agents according to their sources. Natural antibacterial agents have the advantages of safety, non-toxicity and broad-spectrum bactericidal property, but they cannot be subjected to secondary processing, have low production capacity due to resource constraints, and are very limited in practical application. Artificial antibacterial agents can be divided into organic antibacterial agents and inorganic antibacterial agents according to their components. Organic antibacterial agents can effectively inhibit the growth and reproduction of pathogenic microorganisms, and have the characteristics of fast effect, but they have problems such as poor thermal stability and chemical stability, safety risks, and narrow application range, and are gradually facing elimination. Inorganic antibacterial agents are a kind of antibacterial agents prepared by using the bactericidal or bacteriostatic ability of metals such as silver, zinc, copper and titanium and their ions. Inorganic antibacterial agents have the advantages of broad-spectrum antibacterial property, safety, non-toxicity, good stability, easy production and processing, and can better adapt to the application of actual production and life, can be used to improve and long-term maintain the antibacterial property of daily necessities such as fabrics, plastics and rubbers, and are gradually becoming a research hotspot in the field of antibacterial agents.

[0003] At present, common inorganic antibacterial agents on the market mainly include nano zinc oxide and silver-based antibacterial agents.

[0004] Nano zinc oxide can produce various active oxygen substances, which can cause the denaturation of the cell membrane, protein and plasmid of pathogenic microorganisms, lipid peroxidation, and damage to mitochondria, and induce the necrosis of pathogenic microorganisms, so that the bactericidal effect is remarkable. Nano zinc oxide also has the advantages of safety, non-toxicity, high specific surface, many reaction sites and low price, and can be synthesized by various physical and chemical methods such as solid phase method, liquid phase method and gas phase method. However, as a kind of nano powder, nano zinc oxide is prone to agglomeration, and the agglomeration leads to the existence of micron-sized particles of different sizes in the powder. These agglomerates not only cause the antibacterial performance of the antibacterial agent to decrease, but also affect the doping and dispersion of the antibacterial agent in products such as fabrics, plastics and rubbers, resulting in problems such as color difference and decrease in mechanical strength of these antibacterial products.

[0005] Silver-based antibacterial agents can release silver ions, which can destroy the cell wall of pathogenic microorganisms, inhibit their respiration, and destroy their DNA, thereby killing pathogenic microorganisms. Silver-based antibacterial agents can be divided into supported and non-supported types according to whether silver is loaded on other carriers. Early silver-based antibacterial agents are mainly non-supported, including nano-silver particles, nano-silver sol, silver ion solution, etc. Non-supported silver-based antibacterial agents produce high concentrations of silver ions, have significant bactericidal effects, and see fast results, and can achieve bactericidal effects or improve the antibacterial properties of various daily necessities in a short time. However, since silver is a noble metal, it has poor stability, and silver or silver ions are easily oxidized, especially under the action of ultraviolet light. Oxidized silver can cause the antibacterial properties of daily necessities to decrease rapidly and cause discoloration, thereby affecting use. In addition, silver is also prone to react with elements such as phosphorus and sulfur to cause discoloration. The production and use of plastics, rubber and other daily necessities inevitably involve sulfur elements. The problem of easy oxidation and discoloration of non-supported silver-based antibacterial agents seriously limits their application in various daily necessities. In order to solve this problem, industry researchers have attempted to load silver or silver ions into carriers such as zeolite, silica gel, sodium zirconium hydroxyphosphate, etc., to avoid the oxidation of silver and the reaction of silver with elements such as phosphorus and sulfur, and at the same time, silver can be precipitated or dissolved from the carrier during use, also achieving antibacterial effects. The precipitation of silver in supported silver-based antibacterial agents is a slow and long-term process, has a slow-release effect, and effectively ensures the long-term antibacterial properties of daily necessities. Compared with zeolite, silica gel and other carriers, sodium zirconium hydroxyphosphate has better stability of the loaded silver, and therefore, silver-loaded sodium zirconium phosphate is the most commonly used and most researched type of supported silver ion antibacterial agent. Of course, supported silver ion antibacterial agents such as sodium zirconium hydroxyphosphate also have some problems, such as insufficient silver ion loading leading to insufficient bactericidal effect, and the high price of silver-based antibacterial agents due to silver being a noble metal.

[0006] The application of CN114957734A, "Preparation method and application of an antibacterial agent and a composite material containing the antibacterial agent", discloses that 100 parts by weight of a thermoplastic elastomer material, 5-30 parts by weight of a porous material supported guanidine salt antibacterial agent, 50-200 parts by weight of a filling oil, 5-30 parts by weight of a silver-loaded sodium zirconium phosphate antibacterial agent and / or 10-60 parts by weight of nano-zinc oxide are uniformly plasticized, and then screw extrusion granulation is performed to obtain a composite antibacterial master batch. SUMMARY

[0007] The problem to be solved by the present application is to provide a preparation method of a nano-zinc oxide composite silver ion antibacterial agent with good antibacterial performance.

[0008] To solve the above problems, the present application provides a preparation method of a nano-zinc oxide composite silver ion antibacterial agent, comprising the following steps:

[0009] I. Synthesizing nano-zinc oxide by sol-gel method;

[0010] II. Silver ions were loaded onto sodium zirconium phosphate using an ion exchange method to obtain silver-loaded sodium zirconium phosphate.

[0011] III. A nano-zinc oxide composite silver ion antibacterial agent was obtained by combining nano-zinc oxide and silver-loaded sodium zirconium phosphate using a liquid-phase method.

[0012] As an improvement to the preparation method of the nano-zinc oxide composite silver ion antibacterial agent of the present invention, step one includes the following steps:

[0013] 1.1) Prepare an ethanol aqueous solution with a mass fraction of 80% to 95%, and divide it into two equal parts; add zinc acetate to one part of the ethanol aqueous solution to obtain an ethanol aqueous solution with a mass fraction of 2% to 4% (preferably 3%) of zinc acetate; add sodium hydroxide to the other part of the ethanol aqueous solution to obtain an ethanol aqueous solution with a mass fraction of 0.5% to 1% (preferably 0.75%) of sodium hydroxide.

[0014] Under conditions of 0–30°C (preferably 20–30°C) and stirring, sodium hydroxide alcohol aqueous solution is added dropwise to zinc acetate alcohol aqueous solution for 5–10 min. After the addition is complete, the mixture is kept warm and stirred for another 5–10 min, and then kept warm and allowed to stand for 20–40 min (e.g., 30 min).

[0015] 1.2) Add water to the substance obtained in step 1.1), shake well, and centrifuge to obtain precipitate I. Wash precipitate I with water by centrifugation (2-3 times); then dry (place in a vacuum oven at 60±10℃ and dry until constant weight) to obtain nano zinc oxide powder.

[0016] Note: The amount of water used when adding water and shaking well is approximately 2 to 3 times the sum of the volumes of the two equal portions of the ethanol aqueous solution.

[0017] As a further improvement to the preparation method of the nano-zinc oxide composite silver ion antibacterial agent of the present invention, step two includes the following steps:

[0018] 2.1) Disperse sodium zirconium phosphate in deionized water to obtain a carrier suspension, wherein the mass fraction of sodium zirconium phosphate in the carrier suspension is 2.5% to 5% (preferably 3% to 4.5%); dissolve silver nitrate in deionized water to obtain a silver source solution, wherein the mass fraction of silver nitrate in the silver source solution is 1% to 1.5%;

[0019] First, mix the carrier suspension and the silver source solution at a volume ratio of 1:2 to 4 (preferably 1:3 to 4), then adjust the pH to 3 to 4, and stir the reaction at 40±10℃ for 4 to 6 hours.

[0020] 2.2) Add water to the product obtained in step 2.1), shake well, and centrifuge to obtain precipitate II; wash precipitate II with water by centrifugation (2-3 times); then dry (place in a vacuum oven at 60±10℃ to dry until constant weight) to obtain white powder A;

[0021] Note: The amount of water used when adding water and shaking well is approximately 2 to 3 times the mass of the product obtained in step 2.1);

[0022] 2.3) Replace sodium zirconium hydroxyphosphate with white powder A and repeat steps 2.1) to 2.2) above to obtain white powder B;

[0023] 2.4) The white powder B is calcined at a temperature of 700-900℃ (preferably 800℃) for 2-3 hours to obtain silver-loaded sodium zirconium phosphate powder.

[0024] As a further improvement to the preparation method of the nano-zinc oxide composite silver ion antibacterial agent of the present invention, step three includes the following steps:

[0025] 3.1) Disperse the nano zinc oxide powder obtained in step one in deionized water, add activator and surfactant, stir for 3-5 min, then add the silver-loaded sodium zirconium phosphate powder obtained in step two, and continue stirring for 30-60 min to obtain a mixture.

[0026] In the mixture, the mass fraction of nano zinc oxide is 1% to 3% (preferably 2% to 3%), the mass fraction of silver-loaded sodium zirconium phosphate is 1%, the mass fraction of surfactant is 0.1% to 0.5% (preferably 0.3% to 0.4%), and the mass fraction of activator is 0.1% to 0.5% (preferably 0.2% to 0.4%).

[0027] 3.2) The mixture obtained in step 3.1) was filtered, and the precipitate was dried (placed in a vacuum oven at 60±10℃ and dried until constant weight) to obtain white powder C;

[0028] 3.3) The white powder C obtained in step 3.2) is calcined (calcination removes surfactant and activator) at a temperature of 600±50℃ for 3±0.5h to obtain nano zinc oxide composite silver ion antibacterial agent.

[0029] As a further improvement to the preparation method of the nano zinc oxide composite silver ion antibacterial agent of the present invention, in step 2.1): sodium zirconium hydroxyphosphate is a cubic crystal of 1-3 μm (sodium zirconium hydroxyphosphate cubic crystal powder); and citric acid is used to adjust the pH.

[0030] As a further improvement to the preparation method of the nano zinc oxide composite silver ion antibacterial agent of the present invention, in step 3.1): the surfactant is sodium dodecyl sulfate or sodium dodecylbenzene sulfonate, and the activator is stearic acid.

[0031] The present invention also provides a nano-zinc oxide composite silver ion antibacterial agent prepared according to the above preparation method.

[0032] Compared with the prior art, the technical advantages of the present invention are:

[0033] 1. Silver-loaded sodium zirconium phosphate powder was obtained by loading silver ions onto a sodium zirconium phosphate support via ion exchange. The loading capacity of silver was increased by optimizing the loading process and performing multiple ion exchanges.

[0034] 2. By using a liquid-phase method to composite nano-zinc oxide and silver-loaded sodium zirconium phosphate, the nano-zinc oxide particles can be more uniformly composited on the surface of the cubic crystals of silver-loaded sodium zirconium phosphate, reducing the agglomeration of nano-zinc oxide.

[0035] 3. Nano zinc oxide and silver-loaded sodium zirconium phosphate are combined to prepare nano zinc oxide composite silver ion antibacterial agent, which reduces the use of silver-based antibacterial agents and lowers costs. At the same time, due to the difference in the antibacterial mechanism of zinc oxide and silver ions, the combined use has a synergistic antibacterial mechanism, and the composite antibacterial agent has better antibacterial performance. Attached Figure Description

[0036] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0037] Figure 1 SEM image of the nano-zinc oxide composite silver ion antibacterial agent prepared in Example 1;

[0038] Figure 1 In the image, the left image was taken at 2500x magnification, and the right image was taken at 10000x magnification.

[0039] Figure 2 EDS image of the nano-zinc oxide composite silver ion antibacterial agent prepared in Example 1;

[0040] The images show the distribution of six elements—Zr, P, Zn, Na, O, and Ag—in the antibacterial agent. The EDS layered image is the superposition result of the distribution of these six elements, indicating that the six elements are evenly distributed in the antibacterial agent.

[0041] Figure 3 The image shows the XRD pattern of the nano-zinc oxide composite silver ion antibacterial agent prepared in Example 1. Detailed Implementation

[0042] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0043] Example 1: A method for preparing a nano-zinc oxide composite silver ion antibacterial agent, comprising the following three steps:

[0044] I. Synthesis of high-purity nano-zinc oxide using the sol-gel method, including the following steps:

[0045] 1.1) Prepare an 80% (w / w) aqueous ethanol solution and divide it into two equal portions;

[0046] Add zinc acetate to one portion of the ethanol aqueous solution to obtain a zinc acetate alcohol aqueous solution with a zinc acetate mass fraction of 3%; add sodium hydroxide to another portion of the ethanol aqueous solution to obtain a sodium hydroxide alcohol aqueous solution with a sodium hydroxide mass fraction of 0.75%.

[0047] At 25°C and with stirring, the above sodium hydroxide alcohol aqueous solution was added dropwise to the zinc acetate alcohol aqueous solution over a period of 10 minutes. The solution was kept at 25°C and stirred for another 5 minutes. After stirring, the solution was kept at 25°C and allowed to stand for 30 minutes.

[0048] 1.2) Add water to the product obtained in step 1.1) and shake well (the amount of water is approximately twice the sum of the volumes of the two equal portions of the ethanol aqueous solution). Centrifuge to obtain a precipitate. Continue to wash the precipitate with water by centrifugation twice (until the eluent is neutral).

[0049] The washed precipitate was dried in a vacuum oven at 60°C until constant weight was obtained to obtain nano zinc oxide powder.

[0050] II. Loading silver ions onto sodium zirconium phosphate using an ion exchange method, including the following steps:

[0051] 2.1) Disperse cubic crystalline sodium zirconium phosphate powder with a particle size of 1-3 μm in deionized water to obtain a carrier suspension, wherein the mass fraction of sodium zirconium phosphate in the carrier suspension is 4.5%; dissolve silver nitrate in deionized water to obtain a silver source solution, wherein the mass fraction of silver nitrate in the silver source solution is 1.5%.

[0052] The carrier suspension and the silver source solution were mixed at a volume ratio of 1:4, and an appropriate amount of citric acid was added to adjust the pH to 3.5. The mixture was then stirred at 40°C for 5 hours.

[0053] 2.2) Add water (approximately twice the amount of water used in step 2.1) to the product obtained in step 2.1), shake well, and centrifuge to obtain a precipitate. Continue to wash the precipitate twice with water by centrifugation (until the eluent is neutral). Then place it in a vacuum oven at 60°C and dry until completely dry to obtain white powder A.

[0054] 2.3) Replace sodium zirconium hydroxyphosphate cubic powder with white powder A and repeat steps 2.1) to 2.2) once to obtain white powder B.

[0055] 2.4) White powder B was calcined at 800℃ for 2 hours to obtain silver-loaded sodium zirconium phosphate powder.

[0056] III. The composite of nano-zinc oxide and silver-loaded sodium zirconium phosphate using a liquid-phase method includes the following steps:

[0057] 3.1) Disperse the nano zinc oxide powder obtained in step one in deionized water, add activator and surfactant, stir for 5 min, then add the silver-loaded sodium zirconium phosphate powder obtained in step two, and continue stirring for 45 min to obtain a mixture.

[0058] In the mixture, the mass fraction of nano-zinc oxide is 2%, the mass fraction of silver-loaded sodium zirconium phosphate is 1%, the mass fraction of surfactant is 0.3%, and the mass fraction of activator is 0.2%.

[0059] The surfactant is sodium dodecyl sulfate, and the activator is stearic acid.

[0060] 3.2) The mixture obtained in step 3.1) is filtered to obtain a precipitate. The precipitate is dried in a vacuum oven at 60°C until constant weight is obtained to obtain a white powder.

[0061] 3.3) The white powder obtained in step 3.2) is calcined at 600℃ for 3 hours to obtain nano zinc oxide composite silver ion antibacterial agent.

[0062] Example 1 synthesized a nano-zinc oxide composite silver ion antibacterial agent. The composition and structure were characterized by SEM, EDS, and XRD. The SEM and EDS tests were performed using a Hitachi SU8010 field emission scanning electron microscope, and the XRD tests were performed using a Panaco X'Pert PRO MPD X-ray powder diffractometer. (SEM image...) Figure 1 The image shows nano-zinc oxide uniformly composited on the surface of 1-3 μm zirconium phosphate sodium silver cubic crystals. (EDS image) Figure 2 The XRD pattern shows that the antibacterial agent contains Zr, P, Zn, Na, O, Ag, and other elements, which are evenly distributed. Figure 3 The results show that sodium zirconium phosphate and zinc oxide crystalline phases are present in the antibacterial agent sample.

[0063] Example 2: A method for preparing a nano-zinc oxide composite silver ion antibacterial agent, with the following changes compared to Example 1:

[0064] In step 2.1): the mass fraction of sodium zirconium hydroxyphosphate in the carrier suspension was changed from 4.5% to 3%; the mass fraction of silver nitrate in the silver source solution was changed from 1.5% to 1%; and the stirring reaction time was changed from 5h to 4h.

[0065] The rest is the same as in Example 1.

[0066] Example 3: A method for preparing a nano-zinc oxide composite silver ion antibacterial agent, with the following changes compared to Example 1:

[0067] In step 2.1), the volume ratio of the carrier suspension to the silver source solution was changed from 1:4 to 1:3, and the stirring reaction time was changed from 5h to 6h.

[0068] The rest is the same as in Example 1.

[0069] Example 4: A method for preparing a nano-zinc oxide composite silver ion antibacterial agent, with the following changes compared to Example 1:

[0070] In the mixture of step 3.1): the mass fraction of nano zinc oxide is changed from 2% to 3%, the mass fraction of surfactant is changed from 0.3% to 0.4%, and the mass fraction of activator is changed from 0.2% to 0.3%.

[0071] The rest is the same as in Example 1.

[0072] Example 5: A method for preparing a nano-zinc oxide composite silver ion antibacterial agent, with the following changes compared to Example 1:

[0073] In the mixture of step 3.1): the surfactant is changed from sodium dodecyl sulfate to sodium dodecylbenzene sulfonate, and the mass fraction of the surfactant is changed from 0.3% to 0.4%.

[0074] The rest is the same as in Example 1.

[0075] Comparative Example 1, compared to Example 1, is modified as follows:

[0076] In step 2.1), the volume ratio of the carrier suspension and the silver source solution was changed from 1:4 to 1:1; the rest was the same as in Example 1.

[0077] Comparative Example 2, compared to Example 1, made the following changes:

[0078] In step 2.1), the mass fraction of silver nitrate in the silver source solution is changed from 1.5% to 0.5%; the rest is the same as in Example 1.

[0079] Comparative Example 3, compared to Example 1, made the following changes:

[0080] In step 2.1), the reaction time was changed from 5 hours to 2 hours; the rest was the same as in Example 1.

[0081] Comparative Example 4, compared to Example 1, is modified as follows:

[0082] The repeated processing in step 2.3) is cancelled, and the white powder A obtained in step 2.2) is directly calcined in step 2.4), and the rest is the same as in Example 1.

[0083] Comparative Example 5, compared to Example 1, is modified as follows:

[0084] The use of surfactant in step 3.1) is cancelled, that is, the mass fraction of surfactant is 0%, and the rest is the same as in Example 1.

[0085] Comparative Example 6, compared to Example 1, is modified as follows:

[0086] Change step three to a solid-phase mixing method:

[0087] Nano zinc oxide powder and silver-loaded sodium zirconium phosphate powder were added to a dry mixer one after another and stirred for 60 minutes to obtain a composite antibacterial agent. The mass ratio of nano zinc oxide powder to silver-loaded sodium zirconium phosphate powder was still 2:1.

[0088] The rest is the same as in Example 1.

[0089] Comparative Example 7: Only the nano zinc oxide powder obtained in step one of Example 1 was used as the antibacterial agent.

[0090] Comparative Example 8: Only the silver-loaded sodium zirconium phosphate powder obtained in step two of Example 1 was used as the antibacterial agent.

[0091] Comparative Example 9: The calcination treatment in step 3.3) was omitted; that is, the white powder obtained in step 3.2) was used directly as the antibacterial agent. The rest was the same as in Example 1.

[0092] To reflect the technical advantages of the ion exchange process used in step two of this invention, the antibacterial agents prepared in Examples 1, 2, 3, and Comparative Examples 1-4 were compared by EDS testing. The mass fractions of Ag and Na elements were compared, and the proportion of Ag atoms to the total number of Na and Ag atoms was defined as the Ag loading. The results are shown in Table 1.

[0093] Table 1

[0094] Serial number Na mass fraction wt% Ag mass fraction wt% Ag loading Example 1 5.19％ 1.23％ 4.80％ Example 2 5.23％ 1.23％ 4.77％ Example 3 5.22％ 1.23％ 4.78％ Comparative Example 1 5.95％ 0.53％ 1.86％ Comparative Example 2 5.83％ 0.57％ 2.04％ Comparative Example 3 6.13％ 0.27％ 0.93％ Comparative Example 4 5.53％ 0.86％ 3.21％

[0095] Taking Example 1 as an example, after conversion, the number of Ag atoms is 1.23 / 108 = 0.0114, and the number of Na atoms is 0.2257. Therefore, the Ag loading is 0.0114 / (0.0114+0.2257) = 4.80%.

[0096] To demonstrate the superior antibacterial properties of the nano-zinc oxide composite silver ion antibacterial agent prepared in this invention, antibacterial silicone rubber samples were prepared by incorporating the antibacterial agents of Examples 1-5 and Comparative Examples 1-9 into the same liquid silicone rubber (liquid silicone rubber from Zhejiang Zhongtian Dongfang Fluorosilicon Materials Co., Ltd.). The amount of antibacterial agent incorporated was 1.2% (mass%). Twelve 5cm*5cm*0.2cm pieces were cut from each sample for antibacterial rate testing against *Escherichia coli* and *Staphylococcus aureus*. The antibacterial rate test was performed according to the national standard WS / T 650-2019. The antibacterial rates of all antibacterial silicone rubber samples against the two pathogenic microorganisms are shown in Table 2. The antibacterial agents prepared in Examples 1-5, after incorporation into the silicone rubber, resulted in antibacterial rates exceeding 90% and 99% against *Escherichia coli* and *Staphylococcus aureus*, respectively. The Ag loading of the antibacterial agents in Comparative Examples 1-4 decreased, leading to a significant decrease in the antibacterial effect. In Comparative Examples 5 and 6, the nano-zinc oxide and silver-loaded sodium zirconium phosphate were not uniformly combined, resulting in a decrease in the antibacterial effect of the composite antibacterial agent. Comparative Examples 7 and 8 used only nano-zinc oxide and silver-loaded sodium zirconium phosphate, respectively, and their antibacterial effects were inferior to the composite antibacterial agent of this invention. In Comparative Example 9, the surfactant was not removed by calcination, and due to the decreased proportion of effective antibacterial components in the composite antibacterial agent, the antibacterial effect was reduced.

[0097] Table 2

[0098] Bacteriostatic rate (Escherichia coli) Bacteriostatic rate (Staphylococcus aureus) Example 1 91.2％ 99.9％ Example 2 90.9％ 99.8％ Example 3 91.0％ 99.8％ Example 4 91.1％ 99.9％ Example 5 91.2％ 99.9％ Comparative Example 1 64.3％ 70.5％ Comparative Example 2 68.0％ 76.7％ Comparative Example 3 49.3％ 54.9％ Comparative Example 4 79.1％ 88.4％ Comparative Example 5 86.7％ 95.2％ Comparative Example 6 80.1％ 89.0％ Comparative Example 7 78.8％ 87.5％ Comparative Example 8 89.6％ 99.0％ Comparative Example 9 89.5％ 96.1％

[0099] Finally, it should be noted that the above examples are merely some specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments and many variations are possible. All variations that can be directly derived or conceived by those skilled in the art from the disclosure of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a nano-zinc oxide composite silver ion antibacterial agent, characterized in that... Includes the following steps: I. Synthesis of nano-zinc oxide using the sol-gel method, including the following steps: 1.1) Prepare an ethanol aqueous solution with a mass fraction of 80%~95%, and divide it into two equal parts; add zinc acetate to one part of the ethanol aqueous solution to obtain an ethanol aqueous solution with a mass fraction of 2%~4%; add sodium hydroxide to the other part of the ethanol aqueous solution to obtain an ethanol aqueous solution with a mass fraction of 0.5%~1%; At 0~30℃ and under stirring conditions, add sodium hydroxide alcohol aqueous solution dropwise to zinc acetate alcohol aqueous solution over a period of 5~10 min. After the addition is complete, continue stirring at the temperature for another 5~10 min, and then let it stand at the temperature for 20~40 min. 1.2) Add water to the substance obtained in step 1.1), shake well, and centrifuge to obtain precipitate I. Wash precipitate I with water by centrifugation and then dry to obtain nano zinc oxide powder. II. Silver-loaded sodium zirconium phosphate is obtained by loading silver ions onto sodium zirconium phosphate using an ion exchange method, including the following steps: 2.1) Sodium zirconium hydroxyphosphate was dispersed in deionized water to obtain a carrier suspension, wherein the mass fraction of sodium zirconium hydroxyphosphate in the carrier suspension was 2.5%~5%; silver nitrate was dissolved in deionized water to obtain a silver source solution, wherein the mass fraction of silver nitrate in the silver source solution was 1%~1.5%; First, mix the carrier suspension and the silver source solution at a volume ratio of 1:2~4, then adjust the pH to 3~4, and stir the reaction at 40±10 ℃ for 4~6 hours; 2.2) Add water to the product obtained in step 2.1), shake well, and centrifuge to obtain precipitate II; wash precipitate II with water by centrifugation; then dry to obtain white powder A; 2.3) Replace sodium zirconium hydroxyphosphate with white powder A and repeat steps 2.1) to 2.2) above to obtain white powder B; 2.4) The white powder B was calcined at a temperature of 700~900 ℃ for 2~3 h to obtain silver-loaded sodium zirconium phosphate powder. III. A nano-zinc oxide composite silver ion antibacterial agent is obtained by combining nano-zinc oxide and silver-loaded sodium zirconium phosphate using a liquid-phase method, including the following steps: 3.1) Disperse the nano zinc oxide powder obtained in step one in deionized water, add activator and surfactant, stir for 3-5 min, then add the silver-loaded sodium zirconium phosphate powder obtained in step two, and continue stirring for 30-60 min to obtain a mixture. In the mixture, the mass fraction of nano-zinc oxide is 1%~3%, the mass fraction of silver-loaded sodium zirconium phosphate is 1%, the mass fraction of surfactant is 0.1%~0.5%, and the mass fraction of activator is 0.1%~0.5%. 3.2) The mixture obtained in step 3.1) is filtered, and the resulting precipitate is dried to obtain white powder C; 3.3) The white powder C obtained in step 3.2) is calcined at a temperature of 600±50 ℃ for 3±0.5 h to obtain nano zinc oxide composite silver ion antibacterial agent.

2. The preparation method of the nano-zinc oxide composite silver ion antibacterial agent according to claim 1, characterized in that: In step 2.1): sodium zirconium hydroxyphosphate is a cubic crystal with a size of 1-3 μm; pH is adjusted using citric acid.

3. The preparation method of the nano-zinc oxide composite silver ion antibacterial agent according to claim 2, characterized in that: In step 3.1): the surfactant is sodium dodecyl sulfate or sodium dodecylbenzene sulfonate, and the activator is stearic acid.

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