Nanosilver spray, preparation method and application thereof

Abstract

This invention discloses a nano-silver spray, its preparation method, and its application, belonging to the field of disinfection and antibacterial technology for cultural relic protection. The nano-silver spray of this invention is composed of magnetic nano-silver composite material, ammonium lauryl sulfate, chitosan, ethanol, and deionized water. By rationally proportioning dispersants and stabilizers, and combining them with a uniformly sized magnetic nano-silver composite material, the prepared nano-silver spray exhibits highly efficient inhibitory activity against various bacteria that harm silk textiles. After treatment of silk textiles, the color difference ΔE of the textiles is ≤2.33, the mechanical properties remain largely unchanged, the fiber morphology is undamaged, and the chemical structure of the proteins in the textiles is unaffected, demonstrating good safety and practicality. Furthermore, after treatment, by contacting the surface of the textiles with an external permanent magnet for 5-10 minutes, the recovery rate of the magnetic nano-silver composite material can reach 50%, effectively reducing the residue of heavy metals in the textiles and the environment.

Description

Technical Field

[0001] This invention belongs to the field of disinfection and antibacterial technology for cultural relic protection, and more specifically, relates to a nano-silver spray, its preparation method, and its application. Background Technology

[0002] Silk artifacts, due to their material properties, are highly susceptible to microbial attack, leading to fiber degradation, color changes, and structural damage. Currently, mold and decay are significant factors contributing to the destruction of silk artifacts in museum collections. Common harmful microorganisms include Aspergillus niger, Penicillium citrinum, and Escherichia coli, with Aspergillus niger being the most damaging due to its strong acid production and high tolerance. Organic acids and proteases produced by microbial metabolism cause the hydrolysis and breakage of silk fibers, resulting in structural damage and color changes. Achieving effective and continuous antimicrobial protection without damaging the artifact itself is a pressing technical challenge in the field of cultural relic preservation.

[0003] Traditional methods for the antibacterial preservation of cultural relics mainly include: modified atmosphere storage (MAP) with low oxygen or nitrogen purging, ultraviolet irradiation sterilization, chemical fumigation (such as ethylene oxide, sulfuryl fluoride, etc.), and topical application of antibacterial agents. However, all of these methods have certain limitations: MAP is costly and complex to operate; ultraviolet irradiation may cause photodegradation of silk proteins; chemical fumigants are highly toxic and pose potential hazards to both the cultural relics and the human body; and ordinary chemical antibacterial agents suffer from poor antibacterial efficacy and insufficient compatibility with the materials of the cultural relics.

[0004] Nano-silver has been widely used in medical devices, food packaging, and antimicrobial finishing of textiles due to its broad-spectrum and highly effective inhibitory activity against various microorganisms such as bacteria, fungi, and viruses. However, ordinary nano-silver particles tend to agglomerate in aqueous solutions and are difficult to disperse uniformly. Furthermore, they are not easily recovered after being applied to the surface of cultural relics, posing a potential risk of environmental pollution.

[0005] A magnetic composite antibacterial nanomaterial (Fe3O4@SiO2 / Ag) was prepared by combining magnetic iron oxide (Fe3O4) with a silicon dioxide (SiO2) coating layer and silver nanoparticles. + This approach can endow nano-silver with the following advantages: 1) The magnetic core allows the material to be recycled and reused under an external magnetic field, reducing environmental pollution; 2) The SiO2 coating effectively prevents Fe3O4 from being oxidized and improves particle dispersion stability; 3) The material size is in the range of 80-100 nm, which is conducive to uniform adsorption onto the fiber surface. However, at present, research on formulating such magnetic nano-silver composite materials into water-based sprays and applying them to the antibacterial protection of silk fabrics and cultural relics is still lacking, and related products and methods urgently need to be developed.

[0006] Therefore, developing a nano-silver spray that is stable in dispersion, highly effective and long-lasting in antibacterial properties, does not damage cultural relics, and is recyclable provides a safe and reliable technical means for the prevention and control of microorganisms in silk cultural relics. Summary of the Invention

[0007] To address the aforementioned problems in existing technologies, the technical problem this invention aims to solve is to provide a nano-silver spray that exhibits highly effective inhibitory activity against various harmful bacteria species affecting silk artifacts, without significantly impacting the color, mechanical properties, or chemical structure of the silk artifacts. Another technical problem this invention aims to solve is to provide a simple method for preparing the aforementioned nano-silver spray, which is easy to manufacture industrially. A further technical problem this invention aims to solve is to provide the application of the aforementioned nano-silver spray in the disinfection and antibacterial treatment of silk artifact surfaces.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0009] A nano-silver spray is composed of the following raw materials in weight percentages: nano-silver 0.5wt%~2wt%, dispersant 0.1wt%~2wt%, stabilizer 0.05wt%~0.1wt%, ethanol 0.5wt%~2wt%, and the balance being deionized water; wherein, the nano-silver is a magnetic nano-silver composite material with a core-shell structure, the core being magnetic iron tetroxide and the shell being silicon dioxide, and silver ions are distributed in the silicon dioxide shell through adsorption.

[0010] Preferably, the dispersant is ammonium lauryl sulfate.

[0011] Preferably, the stabilizer is chitosan.

[0012] Preferably, the amount of the magnetic silver nanocomposite material is 0.7wt%~1.5wt%, the amount of the dispersant is 0.3wt%~1wt%, the amount of the stabilizer is 0.06wt%~0.09wt%, and the amount of ethanol is 0.8wt%~1.5wt%.

[0013] Preferably, the amount of the magnetic silver nanocomposite material is 1 wt%, the amount of the dispersant is 0.5 wt%, the amount of the stabilizer is 0.07 wt%, and the amount of ethanol is 1 wt%.

[0014] A method for preparing the nano-silver spray includes the following steps:

[0015] 1) Weigh the dispersant and stabilizer according to the weight percentage, add them to deionized water, stir to dissolve, then add ethanol and continue stirring to mix evenly;

[0016] 2) Add magnetic silver nanocomposite material to the solution obtained in step 1) and ultrasonically disperse it for 20 min at room temperature to obtain silver nanospray.

[0017] Preferably, in step 2), the preparation of the magnetic silver nanocomposite material includes the following steps:

[0018] S1. Disperse the oil phase Fe3O4 in methanol, centrifuge and discard the supernatant, add CTAB solution and ammonia, vortex and centrifuge, and take the supernatant.

[0019] S2. Add the supernatant obtained in step S1 to an ascorbic acid aqueous solution, adjust the pH to 9, dilute with water, heat and stir, and add tetraethyl orthosilicate and bis(triethoxysilyl)ethane to react.

[0020] S3. After mixing the original solution obtained in step S2 with ethanol evenly, centrifuge to precipitate and wash to obtain Fe3O4@SiO2.

[0021] S4. Add silver nitrate solution to the Fe3O4@SiO2 obtained in step S3, ultrasonically vibrate, centrifuge, and wash to obtain the magnetic silver nanocomposite material Fe3O4@SiO2 / Ag. + .

[0022] The application of the nano-silver spray in the disinfection and antibacterial treatment of silk artifacts.

[0023] Preferably, the disinfection and antibacterial treatment is used to inhibit Penicillium citrinum, Aspergillus niger and Escherichia coli.

[0024] Preferably, the nano-silver spray is uniformly sprayed onto the surface of the silk artifact, with a spraying rate of 0.5~5 mL / m². 2 After spraying, allow it to air dry at room temperature to complete the antibacterial treatment. After the treatment is completed, the magnetic nanoparticles can be recovered by adding an external permanent magnet for 5-10 minutes.

[0025] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0026] 1) This invention uses magnetic Fe3O4 as the core, SiO2 as the coating shell, and Ag loaded on the surface. + The composite nanomaterials were formulated into a water-based dispersion suitable for spraying; the magnetic core imparts recyclability to the material, the SiO2 shell ensures particle dispersion stability, and Ag... + As an effective antibacterial ingredient;

[0027] 2) The nano-silver spray prepared by this invention has highly efficient inhibitory activity against various harmful bacteria species on silk cultural relics. Among them, the minimum inhibitory concentrations against Escherichia coli, Penicillium citrinum, and Aspergillus niger are 20 μg / mL, 40 μg / mL, and 70 μg / mL, respectively.

[0028] 3) When the nano-silver spray prepared in this invention is used to treat silk artifacts, the color difference ΔE of the silk artifacts is ≤2.33, the mechanical properties (tear strength) show no significant change, the fiber morphology is not damaged, and the shift of the amide peak in the infrared spectrum is ≤±1cm. -1 It has no impact on the protein chemical structure of cultural relics and has good safety and practicality. In addition, after treatment, the magnetic nano-silver composite material can achieve a recovery rate of up to 50% by contacting the surface of the cultural relics with an external permanent magnet for 5 to 10 minutes, which can effectively reduce the residue of heavy metals in cultural relics and the environment.

[0029] 4) The preparation method of this invention is environmentally friendly, simple, and low in cost. It can be mass-produced and is suitable for antibacterial needs in multiple stages such as cultural relic restoration and daily maintenance. It is highly practical and has high promotion value. Attached Figure Description

[0030] Figure 1 The Fe3O4@SiO2 / Ag prepared for this invention + Transmission electron microscope image;

[0031] Figure 2 The Fe3O4@SiO2 / Ag prepared for this invention + EDS element distribution diagram;

[0032] Figure 3 The image shows the antibacterial effect of the nano-silver spray prepared in Example 2 on Aspergillus niger, Penicillium citrinum, and Escherichia coli at the working concentration. Among them, A-1 is the control group of Escherichia coli + water, A-2 is the experimental group of Escherichia coli + 70 μg / mL nano-silver spray, B-1 is the control group of Aspergillus niger + water, B-2 is the experimental group of Aspergillus niger + 70 μg / mL nano-silver spray, C-1 is the control group of Penicillium citrinum + water, and C-2 is the experimental group of Penicillium citrinum + 70 μg / mL nano-silver spray. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is further described below with reference to specific embodiments. Unless otherwise specified, the technical means used in the following embodiments are all conventional means well known to those skilled in the art. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0034] The nanosilver used in the following examples is a magnetic nanosilver composite material (Fe3O4@SiO2 / Ag). + The specific preparation process is as follows:

[0035] 1) Oil-phase Fe3O4 nanoparticles were prepared by thermal decomposition (using ferric oleate as a precursor, thermally decomposed in a high-boiling-point solvent at 220°C for 30 min).

[0036] 2) Take 400 μL of the oil phase Fe3O4 obtained in step 1) and disperse it in 600 μL of methanol. Centrifuge at 8000 rpm for 5 min and discard the supernatant.

[0037] 3) Add 800 μL of CTAB with a concentration of 100 mg / mL and 1 mL of ammonia (concentrated ammonia diluted 3 times) to the iron oxide obtained in step 2), vortex for 10 min, centrifuge at 8000 rpm for 5 min, take the supernatant, add 1 mL of deionized water to the remaining precipitate, centrifuge, take the supernatant, and repeat twice.

[0038] 4) Add the supernatant obtained in step 3) to an ascorbic acid aqueous solution with a concentration of 100 mg / mL to adjust the pH to 9. Dilute the supernatant with water to 120 mL, heat to 45 °C, stir and control the speed at 500 rpm, add 90 μL tetraethyl orthosilicate (TEOS), add 60 μL TEOS again after 1 h, raise the temperature to 85 °C after 1 h, and finally add 90 μL bis(triethoxysilyl)ethane (BTSE). After reacting for 1 h, cool down to 45 °C and continue stirring for more than 20 h to complete the SiO2 shell coating.

[0039] 5) After mixing the original solution obtained in step 4) with ethanol at a 1:1 ratio, centrifuge to precipitate, use 1%wt guanidine hydrochloride solution as washing solution to wash away CTAB, and finally wash with ethanol and water three times each to obtain Fe3O4@SiO2.

[0040] 6) Add 0.1 mol / L silver nitrate solution to the Fe3O4@SiO2 obtained in step 5), sonicate for 30 min, let stand for 1 h, sonicate again for 10 min, centrifuge at 8000 rpm for 5 min, and finally wash three times with deionized water to obtain Fe3O4@SiO2 / Ag. + The magnetic nano-silver composite material should be stored in a 4°C refrigerator for later use.

[0041] Depend on Figure 1 and Figure 2 It can be seen that the prepared Fe3O4@SiO2 / Ag + The dispersion effect is good, the core-shell structure is clear, the Fe core, Si shell and surface Ag are evenly distributed, the particle size is concentrated in the range of 80-100nm, and each composite particle encapsulates 3-4 Fe3O4 magnetic cores.

[0042] Example 1

[0043] A nano-silver spray is composed of the following raw materials in weight percentage: 0.5 wt% nano-silver, 0.1 wt% ammonium lauryl sulfate, 0.05 wt% chitosan, 0.5 wt% ethanol, and the balance being deionized water;

[0044] The preparation method of the above-mentioned nano-silver spray includes the following steps:

[0045] 1) Weigh 0.1g of ammonium lauryl sulfate and 0.05g of chitosan, dissolve them in 98.85g of deionized water, add 0.5g of ethanol, and mix well;

[0046] 2) Add 0.5g of nano-silver to the solution obtained in step 1), disperse it ultrasonically for 20min, fill it into a spray bottle, seal it, and obtain nano-silver spray.

[0047] Example 2

[0048] A nano-silver spray is composed of the following raw materials by weight percentage: 1 wt% nano-silver, 0.5 wt% ammonium lauryl sulfate, 0.07 wt% chitosan, 1 wt% ethanol, and the balance being deionized water;

[0049] The preparation method of the above-mentioned nano-silver spray includes the following steps:

[0050] 1) Weigh 0.5g of ammonium lauryl sulfate and 0.07g of chitosan, dissolve them in 97.57g of deionized water, add 1g of ethanol, and mix well;

[0051] 2) Add 1g of nano-silver to the solution obtained in step 1), disperse it ultrasonically for 20min, fill it into a spray bottle, seal it, and obtain nano-silver spray.

[0052] Example 3

[0053] A nano-silver spray is composed of the following raw materials by weight percentage: 2 wt% nano-silver, 1 wt% ammonium lauryl sulfate, 0.1 wt% chitosan, 1.5 wt% ethanol, and the balance being deionized water;

[0054] The preparation method of the above-mentioned nano-silver spray includes the following steps:

[0055] 1) Weigh 1g of ammonium lauryl sulfate and 0.1g of chitosan, dissolve them in 95.4g of deionized water, add 1.5g of ethanol, and mix well;

[0056] 2) Add 2g of nano-silver to the solution obtained in step 1), disperse it ultrasonically for 20min, fill it into a spray bottle, seal it, and obtain nano-silver spray.

[0057] Comparative Example 1

[0058] A spray is composed of the following raw materials by weight percentage: 1 wt% nano silver, 0.07 wt% chitosan, 1 wt% ethanol, and the balance being deionized water;

[0059] The preparation method of the above spray includes the following steps:

[0060] 1) Weigh 0.07g of chitosan, dissolve it in 98.07g of deionized water, add 1g of ethanol, and mix well;

[0061] 2) Add 1g of nano-silver to the solution obtained in step 1), disperse it ultrasonically for 20min, fill it into a spray bottle, seal it, and obtain the spray.

[0062] Tests showed that the spray prepared in Comparative Example 1 exhibited significant sedimentation after standing for 30 minutes, with the absolute value of the Zeta potential dropping to 15 mV. The dispersion stability decreased significantly, and the antibacterial effect was uneven, failing to meet the requirements for artifact treatment.

[0063] Comparative Example 2

[0064] A spray is composed of the following raw materials by weight percentage: 1 wt% nano silver, 0.5 wt% ammonium lauryl sulfate, 1 wt% ethanol, and the balance being deionized water;

[0065] The preparation method of the above spray includes the following steps:

[0066] 1) Weigh 0.5g of ammonium lauryl sulfate, dissolve it in 97.5g of deionized water, add 1g of ethanol, and mix well;

[0067] 2) Add 1g of nano-silver to the solution obtained in step 1), disperse it ultrasonically for 20min, fill it into a spray bottle, seal it, and obtain the spray.

[0068] Tests showed that the spray prepared in Comparative Example 2, after 72 hours of storage, showed a reduction in Ag. + Significant precipitation (increased silver ion concentration), decreased spray stability, and presence of Ag. + There is a risk that excessive release could cause cultural relics to change color.

[0069] Comparative Example 3

[0070] A spray is composed of the following raw materials by weight percentage: 1 wt% ordinary nano silver, 0.5 wt% ammonium lauryl sulfate, 0.07 wt% chitosan, 1 wt% ethanol, and the balance being deionized water;

[0071] Ordinary nano-silver is commercially available ordinary nano-silver with an average particle size of 20nm;

[0072] The preparation method of the above spray includes the following steps:

[0073] 1) Weigh 0.5g of ammonium lauryl sulfate and 0.07g of chitosan, dissolve them in 97.57g of deionized water, add 1g of ethanol, and mix well;

[0074] 2) Add 1g of ordinary nano-silver to the solution obtained in step 1), disperse it ultrasonically for 20min, fill it into a spray bottle, seal it, and obtain the spray.

[0075] Tests showed that after spraying silk artifacts prepared in Comparative Example 3, the active components could not be recovered by magnetic means, and the residual silver (Ag) content was about 3.8 times that of Example 2. Moreover, at the same antibacterial concentration, the spray caused a large color difference (ΔE) to silk samples with different aging degrees, reaching a maximum of 4.1, and the color safety was not as good as the nano silver spray of the present invention.

[0076] Example 4

[0077] The nano-silver spray prepared in Example 2 was subjected to antibacterial activity testing. The testing procedure was as follows: the minimum inhibitory concentration (MIC) against the following three standard bacterial strains was determined using the plate count method and the 3M Petrifilm rapid test strip method. The test strains were: *Escherichia coli* (ATCC 25922), *Penicillium citrinum* (ATCC 1109), and *Aspergillus niger* (ATCC 16404). The results are shown in Table 1 and... Figure 3 As shown.

[0078] Table 1. Minimum inhibitory concentration of nano-silver spray against three types of microorganisms harmful to cultural relics in Example 2.

[0079] strains MIC (μg / mL) E. coli 20 lemon penicillium 40 Aspergillus niger 70

[0080] Table 1 shows that the nano-silver spray prepared in this invention exhibits the strongest inhibitory activity against *Escherichia coli*, with a MIC of 20 μg / mL; followed by *Penicillium citrinum*, with a MIC of 40 μg / mL; and the highest MIC against *Aspergillus niger* (70 μg / mL). Therefore, based on the *Aspergillus niger* MIC, a spray working concentration of not less than 70 μg / mL is recommended. Figure 3 It can be seen that at this working concentration, the nano-silver spray of the present invention can simultaneously and effectively inhibit the above three common harmful microorganisms on silk cultural relics.

[0081] Example 5

[0082] The nano-silver spray prepared in Example 2 was used for safety testing of silk artifacts. The testing process was as follows: Unaged modern mulberry silk plain weave fabric (MNW0), silk fabrics with different degrees of simulated aging (MNW1: 230℃ / 30min + 0.1mol / L NaOH / 2h for mild aging; MNW2: 230℃ / 60min + NaOH for moderate aging; MNW3: 230℃ / 120min + NaOH for severe aging), and actual museum-collected silk artifact samples were used as test objects. The working concentration was 70 μg / mL, and the spraying rate was 2 mL / m³. 2 The safety of the spray treatment was assessed. The results are shown in Table 2.

[0083] Table 2. Safety test results of nano-silver spray on silk fabric samples with different aging levels.

[0084] Test Project MNW0 (Non-aged) MNW1 (mild) MNW2 (Moderate) MNW3 (severe) Cultural Relics Samples Color difference ΔE 1.41 2.33 1.40 1.22 0.04 Tear strength No significant changes No significant changes No significant changes No significant changes — FTIR peak shift <![CDATA[≤±1cm -1 ]]> <![CDATA[≤±1cm -1 ]]> <![CDATA[≤±1cm -1 ]]> <![CDATA[≤±1cm -1 ]]> <![CDATA[≤±1cm -1 ]]> Fiber morphology No damage, particle adsorption surface No damage No damage, filling the crack No damage, filling the crack —

[0085] Table 2 shows that the nano-silver spray prepared by this invention has minimal impact on the color of aged, yellowish silk artifacts, exhibiting superior color safety. Treatment with the nano-silver spray of this invention neither accelerates the aging of artifacts nor negatively affects the mechanical properties of the fibers. Characteristic peaks of silk fibroin before and after treatment: Amide I band (approximately 1617–1621 cm⁻¹). -1 ), Amide II band (approximately 1512–1513 cm) -1 ), Amide III band (approximately 1224–1228 cm) -1 The peak position shift was ≤±1cm. -1 After treatment, the fibers showed no obvious structural damage; the magnetic nanoparticles were only adsorbed onto the fiber surface and did not penetrate into the fiber interior. For aged fibers, the particles could fill the surface cracks, providing a certain degree of physical filling and protection.

[0086] The nano-silver spray prepared in Example 2 was applied at a working concentration of 70 μg / mL and a spraying rate of 2 mL / m³. 2 Silk fabric samples were treated under specific conditions, dried, and then placed in contact with an external permanent magnet for 5–10 minutes. The recovery rate of the magnetic silver nanoparticle composite material in each sample was recorded. The results showed that the recovery rate of the magnetic silver nanoparticle composite material in the unaged sample (MNW0) was 44%, the recovery rate in the slightly aged sample was 51%, the recovery rate in the moderately aged sample was 57%, and the recovery rate in the heavily aged sample (MNW3) was the highest at 65%. The overall recovery rate of the magnetic silver nanoparticle composite material for samples with different aging degrees was 50%. Samples with higher aging degrees exhibit increased fiber surface porosity, more uniform particle adsorption, and higher desorption efficiency under an external magnetic field, thus resulting in a higher recovery rate of the magnetic silver nanoparticle composite material.

[0087] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A nano-silver spray, characterized in that, It is composed of the following raw materials by weight percentage: 0.5wt%~2wt% nano silver, 0.1wt%~2wt% dispersant, 0.05wt%~0.1wt% stabilizer, 0.5wt%~2wt% ethanol, and the balance being deionized water; wherein, the nano silver is a magnetic nano silver composite material with a core-shell structure, the core being magnetic iron tetroxide and the shell being silicon dioxide, and silver ions are distributed in the silicon dioxide shell through adsorption.

2. The nano-silver spray according to claim 1, characterized in that, The dispersant is ammonium lauryl sulfate.

3. The nano-silver spray according to claim 1, characterized in that, The stabilizer is chitosan.

4. The nano-silver spray according to claim 1, characterized in that, The amount of the magnetic silver nanocomposite material is 0.7wt%~1.5wt%, the amount of the dispersant is 0.3wt%~1wt%, the amount of the stabilizer is 0.06wt%~0.09wt%, and the amount of ethanol is 0.8wt%~1.5wt%.

5. The nano-silver spray according to claim 4, characterized in that, The amount of the magnetic silver nanocomposite material is 1 wt%, the amount of the dispersant is 0.5 wt%, the amount of the stabilizer is 0.07 wt%, and the amount of ethanol is 1 wt%.

6. A method for preparing the nano-silver spray according to claim 1, characterized in that, Includes the following steps: 1) Weigh the dispersant and stabilizer according to the weight percentage, add them to deionized water, stir to dissolve, then add ethanol and continue stirring to mix evenly; 2) Add magnetic silver nanocomposite material to the solution obtained in step 1) and ultrasonically disperse it for 20 min at room temperature to obtain silver nanospray.

7. The method for preparing nano-silver spray according to claim 6, characterized in that, In step 2), the preparation of the magnetic silver nanocomposite material includes the following steps: S1. Disperse the oil phase Fe3O4 in methanol, centrifuge and discard the supernatant, add CTAB solution and ammonia, vortex and centrifuge, and take the supernatant. S2. Add the supernatant obtained in step S1 to an ascorbic acid aqueous solution, adjust the pH to 9, dilute with water, heat and stir, and add tetraethyl orthosilicate and bis(triethoxysilyl)ethane to react. S3. After mixing the original solution obtained in step S2 with ethanol evenly, centrifuge to precipitate and wash to obtain Fe3O4@SiO2. S4. Add silver nitrate solution to the Fe3O4@SiO2 obtained in step S3, ultrasonically vibrate, centrifuge, and wash to obtain the magnetic silver nanocomposite material Fe3O4@SiO2 / Ag. + .

8. The application of the nano-silver spray according to any one of claims 1-5 in the disinfection and antibacterial treatment of silk artifacts.

9. The application according to claim 8, characterized in that, The disinfection and antibacterial properties are used to inhibit Penicillium citrinum, Aspergillus niger, and Escherichia coli.

10. The application according to claim 8, characterized in that, The nano-silver spray was evenly applied to the surface of the silk artifact, with a spraying rate of 0.5~5 mL / m². 2 After spraying, allow it to air dry at room temperature to complete the antibacterial treatment. After the treatment is completed, the magnetic nanoparticles can be recovered by adding an external permanent magnet for 5-10 minutes.

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