Antibacterial nano-silver colloidal solution and preparation method thereof

Abstract

The invention relates to the technical field of nano-silver antibacterial solutions, in particular to an antibacterial nano-silver colloidal solution and a preparation method thereof.The antibacterial nano-silver colloidal solution comprises the following raw materials of 0.2%-0.3% of silver nitrate, 0.1%-0.2% of glucose, 1%-3% of silver-loaded particles, 2%-3% of polyvinylpyrrolidone, 30%-40% of deionized water and the balance glycerol; the preparation method comprises the following steps: dissolving silver nitrate in deionized water to obtain a dissolved solution; glucose, the silver-loaded particles, polyvinylpyrrolidone and glycerol are mixed, and a mixed solution is obtained; and combining the dissolved solution and the mixed solution, and carrying out ultrasonic dispersion treatment to prepare the antibacterial nano-silver colloidal solution. According to the antibacterial nano-silver colloidal solution disclosed by the invention, the silver-loaded particles are added, and the nano-silver is sufficiently loaded in the hollow SiO2, so that the slow release of silver ions is realized, the release time is prolonged, the antibacterial aging of the antibacterial nano-silver colloidal solution is improved, and the antibacterial nano-silver colloidal solution has good antibacterial durability.

Description

Technical Field

[0001] The invention relates to the technical field of nano silver antibacterial liquid, in particular to an antibacterial nano silver colloid solution and a preparation method thereof. Background Art

[0002] Nanosilver has extremely strong nanoactivity and shows extraordinary antibacterial ability. It can kill common bacteria, fungi, mycoplasma, chlamydia and other pathogenic microorganisms at extremely low concentrations. Compared with antibiotics, nanosilver has the characteristics of bactericidal effect not affected by pH value, broad-spectrum antibacterial, no drug resistance, long-lasting effect, stronger bactericidal ability when exposed to water, safety and environmental protection, etc. It is an ideal antibacterial material and can be widely used in many industries.

[0003] Since nanosilver particles have a large specific surface area, the particles are very easy to agglomerate to form large agglomerates, which leads to the loss of the proper physical properties and functions of the nanoparticles in the final application, thus affecting the development and application of its products. In order to reduce the occurrence of nanosilver agglomeration, nanosilver is often loaded on various carriers such as zeolite, sepiolite, oxide, etc. to form a relatively stable dispersion; however, when such carriers are directly immersed in silver salt solutions, the exchange amount between them and silver ions is limited, which makes it difficult to load sufficient nanosilver, affecting the persistent antibacterial effect of the nanosilver colloidal solution. Based on this, an antibacterial nanosilver colloidal solution and a preparation method thereof are proposed. Summary of the invention

[0004] To overcome the deficiencies of the prior art, the present invention provides an antibacterial nano-silver colloidal solution and a preparation method thereof, which loads a sufficient amount of nano-silver inside the hollow SiO2 to achieve a slow release of silver ions, prolong the release time, and make it have good antibacterial durability.

[0005] To achieve the above object, the present invention provides the following technical solution: an antibacterial nano silver colloidal solution, comprising the following raw materials, by mass percentage, 0.2-0.3% silver nitrate, 0.1-0.2% glucose, 1-3% silver-carrying particles, 2-3% polyvinyl pyrrolidone, 30-40% deionized water, and the balance being glycerol.

[0006] Preferably, the silver-loaded microparticles are prepared as follows: S1, methyl methacrylate, divinylbenzene, toluene and azobisisobutyronitrile are stirred evenly, and then a polyvinyl alcohol aqueous solution is added to mix, and after the reaction is completed, a sufficient amount of ethanol is added to shake and dissolve the toluene, and the PMMA (polymethyl methacrylate) porous microspheres are obtained by suction filtration, rinsing, and drying; S2, the PMMA porous microspheres are added to a sodium hydroxide solution, and after the stirring reaction is completed, the PMMA porous microspheres are filtered, rinsed, and dried to obtain carboxylated PMMA porous microspheres; S3, the carboxylated PMMA porous microspheres are added to the sodium hydroxide solution, and after the stirring reaction is completed, the PMMA porous microspheres are filtered, rinsed, and dried to obtain carboxylated PMMA porous microspheres; The balls are dispersed in anhydrous ethanol, and then a silver nitrate solution is added to the carboxylated PMMA porous microsphere dispersion, stirred for the first time, and then a polyvinyl pyrrolidone alcohol solution is added, stirred for a second time, to obtain a PMMA-Ag composite microsphere dispersion; S4, ammonia water and tetraethyl orthosilicate are added to the PMMA-Ag composite microsphere dispersion to carry out stirring reaction, and after the reaction is completed, the PMMA-Ag-SiO2 composite microspheres are obtained by suction filtration, rinsing and drying; S5, the PMMA-Ag-SiO2 composite microspheres are calcined at a high temperature to obtain silver-loaded particles.

[0007] Preferably, in step S1, the volume ratio of methyl methacrylate, divinylbenzene, toluene and polyvinyl alcohol aqueous solution is 20:1:2:180; the solid-liquid ratio of azobisisobutyronitrile and divinylbenzene is 1:2.5 g / ml; and the mass concentration of the polyvinyl alcohol aqueous solution is 5%.

[0008] Preferably, in step S2, the concentration of the sodium hydroxide solution is 0.2-0.4 mol / L; the stirring reaction temperature is 75-85° C., and the stirring reaction time is 2-4 h.

[0009] Preferably, in step S3, the solid-liquid ratio of the carboxylated PMMA porous microspheres and anhydrous ethanol is 5 mg / ml; the volume ratio of the carboxylated PMMA porous microsphere dispersion, the silver nitrate solution and the polyvinyl pyrrolidone alcohol solution is 5:5:2; and the concentration of the silver nitrate solution is 0.05 mol / L.

[0010] Preferably, in step S3, the polyvinyl pyrrolidone alcohol solution is prepared by dissolving polyvinyl pyrrolidone in anhydrous ethanol at a solid-liquid ratio of 1:15 g / ml.

[0011] Preferably, in step S3, the initial stirring time is 40-50 min, and the secondary stirring time is 70-90 min.

[0012] Preferably, in step S4, the volume ratio of the PMMA-Ag composite microsphere dispersion, ammonia water and tetraethyl orthosilicate is 50:3:1; and the stirring reaction time is 120-150 min.

[0013] Preferably, in step S5, the high temperature calcination temperature is 500-550°C, and the high temperature calcination time is 100-150 minutes.

[0014] The present invention also provides a method for preparing an antibacterial nano-silver colloidal solution, which specifically comprises the following steps:

[0015] (1) dissolving silver nitrate in deionized water to obtain a solution;

[0016] (2) mixing glucose, silver-loaded particles, polyvinyl pyrrolidone and glycerol to obtain a mixed solution;

[0017] (3) The dissolved solution and the mixed solution are combined and subjected to ultrasonic dispersion treatment to obtain an antibacterial nano-silver colloidal solution.

[0018] The present invention provides an antibacterial nano-silver colloidal solution and a preparation method thereof, which has the following beneficial effects compared with the prior art:

[0019] The invention adds silver-carrying particles, loads sufficient nano-silver inside the hollow SiO2, realizes the slow release of silver ions, prolongs the release time, improves the antibacterial time of the antibacterial nano-silver colloid solution, and makes it have good antibacterial persistence.

[0020] The present invention uses toluene as a pore generator to form more holes inside the PMMA microspheres, providing more loading space for nanosilver and achieving sufficient loading of nanosilver; at the same time, the PMMA microspheres are carboxylated to have negative charges, which can better bind to Ag. + In addition, ammonia and ethyl orthosilicate were used to form SiO2 on the surface of the microspheres, and the PMMA microspheres were removed by high-temperature calcination, so that SiO2 generated mesopores, and nanosilver could be fully loaded in the mesopores of SiO2, thus achieving Ag + Slow release.

[0021] The present invention uses silver nitrate, silver-loaded microparticles and glucose. In the early stage, the exposed nano-silver generated by silver nitrate can be directly released to inhibit bacteria, so as to prevent the slow release of the silver-loaded microparticles from affecting the antibacterial effect in the early stage. In the middle and late stages, the silver-loaded microparticles can be slowly released to achieve the purpose of persistent antibacterial effect. The addition of glucose, in synergy with polyvinyl pyrrolidone, ensures the stability of the exposed nano-silver. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0023] Figure 1IR spectra of PMMA porous microspheres and carboxylated PMMA porous microspheres in Example 3 of the present invention;

[0024] Figure 2 The graph is a graph showing the change in silver ion concentration released by the silver-loaded particles of the present invention as a function of immersion time. DETAILED DESCRIPTION

[0025] The following examples are used to explain the implementation methods of the present application in detail, so that the implementation process of how the present application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0026] Example 1

[0027] The preparation of silver-loaded microparticles is as follows:

[0028] S1, methyl methacrylate, divinylbenzene, toluene and azobisisobutyronitrile are stirred evenly, and then a 5% polyvinyl alcohol aqueous solution is added to mix, and after the reaction is completed, sufficient ethanol is added to shake and dissolve the toluene, and the PMMA porous microspheres are obtained by suction filtration, washing and drying;

[0029] The volume ratio of methyl methacrylate, divinylbenzene, toluene and polyvinyl alcohol aqueous solution is 20:1:2:180; the solid-liquid ratio of azobisisobutyronitrile and divinylbenzene is 1:2.5 g / ml.

[0030] S2. Add PMMA porous microspheres to 0.2 mol / L sodium hydroxide solution, stir and react at 85° C. for 2 h, filter, rinse and dry to obtain carboxylated PMMA porous microspheres.

[0031] S3, dispersing the carboxylated PMMA porous microspheres in anhydrous ethanol at a material-liquid ratio of 5 mg / ml, then adding 0.05 mol / L silver nitrate solution to the obtained carboxylated PMMA porous microsphere dispersion, stirring for the first time for 50 min, then adding polyvinyl pyrrolidone alcohol solution, stirring for the second time for 70 min, to obtain a PMMA-Ag composite microsphere dispersion;

[0032] The volume ratio of the carboxylated PMMA porous microsphere dispersion, the silver nitrate solution and the polyvinyl pyrrolidone alcohol solution is 5:5:2. The polyvinyl pyrrolidone alcohol solution is prepared by dissolving polyvinyl pyrrolidone in anhydrous ethanol at a material-liquid ratio of 1:15 g / ml.

[0033] S4. Add ammonia water and tetraethyl orthosilicate to the PMMA-Ag composite microsphere dispersion. The volume ratio of PMMA-Ag composite microsphere dispersion, ammonia water and tetraethyl orthosilicate is 50:3:1. Stir the reaction for 120 minutes. After suction filtration, rinsing and drying, PMMA-Ag-SiO2 composite microspheres are obtained.

[0034] S5. Calcine the PMMA-Ag-SiO2 composite microspheres at 550°C for 100 min to obtain silver-loaded microparticles.

[0035] Example 2

[0036] The preparation of silver-loaded microparticles is as follows:

[0037] S1, methyl methacrylate, divinylbenzene, toluene and azobisisobutyronitrile are stirred evenly, and then a 5% polyvinyl alcohol aqueous solution is added to mix, and after the reaction is completed, sufficient ethanol is added to shake and dissolve the toluene, and the PMMA porous microspheres are obtained by suction filtration, washing and drying;

[0038] The volume ratio of methyl methacrylate, divinylbenzene, toluene and polyvinyl alcohol aqueous solution is 20:1:2:180; the solid-liquid ratio of azobisisobutyronitrile and divinylbenzene is 1:2.5 g / ml.

[0039] S2. Add PMMA porous microspheres to 0.4 mol / L sodium hydroxide solution, stir and react at 75° C. for 4 h, filter, rinse and dry to obtain carboxylated PMMA porous microspheres.

[0040] S3, dispersing the carboxylated PMMA porous microspheres in anhydrous ethanol at a material-liquid ratio of 5 mg / ml, then adding 0.05 mol / L silver nitrate solution to the obtained carboxylated PMMA porous microsphere dispersion, stirring for the first time for 40 min, then adding polyvinyl pyrrolidone alcohol solution, stirring for the second time for 90 min, to obtain a PMMA-Ag composite microsphere dispersion;

[0041] The volume ratio of the carboxylated PMMA porous microsphere dispersion, the silver nitrate solution and the polyvinyl pyrrolidone alcohol solution is 5:5:2. The polyvinyl pyrrolidone alcohol solution is prepared by dissolving polyvinyl pyrrolidone in anhydrous ethanol at a material-liquid ratio of 1:15 g / ml.

[0042] S4. Add ammonia water and tetraethyl orthosilicate to the PMMA-Ag composite microsphere dispersion. The volume ratio of PMMA-Ag composite microsphere dispersion, ammonia water and tetraethyl orthosilicate is 50:3:1. Stir the reaction for 150 minutes. After suction filtration, rinsing and drying, PMMA-Ag-SiO2 composite microspheres are obtained.

[0043] S5. Calcine the PMMA-Ag-SiO2 composite microspheres at 500°C for 150 min to obtain silver-loaded microparticles.

[0044] Example 3

[0045] The preparation of silver-loaded microparticles is as follows:

[0046] S1, methyl methacrylate, divinylbenzene, toluene and azobisisobutyronitrile are stirred evenly, and then a 5% polyvinyl alcohol aqueous solution is added to mix, and after the reaction is completed, sufficient ethanol is added to shake and dissolve the toluene, and the PMMA porous microspheres are obtained by suction filtration, washing and drying;

[0047] The volume ratio of methyl methacrylate, divinylbenzene, toluene and polyvinyl alcohol aqueous solution is 20:1:2:180; the solid-liquid ratio of azobisisobutyronitrile and divinylbenzene is 1:2.5 g / ml.

[0048] S2. Add PMMA porous microspheres to 0.3 mol / L sodium hydroxide solution, stir and react at 80° C. for 3 h, filter, rinse and dry to obtain carboxylated PMMA porous microspheres.

[0049] S3, dispersing the carboxylated PMMA porous microspheres in anhydrous ethanol at a material-liquid ratio of 5 mg / ml, then adding 0.05 mol / L silver nitrate solution to the obtained carboxylated PMMA porous microsphere dispersion, stirring for the first time for 45 min, then adding polyvinyl pyrrolidone alcohol solution, stirring for the second time for 80 min, to obtain a PMMA-Ag composite microsphere dispersion;

[0050] The volume ratio of the carboxylated PMMA porous microsphere dispersion, the silver nitrate solution and the polyvinyl pyrrolidone alcohol solution is 5:5:2. The polyvinyl pyrrolidone alcohol solution is prepared by dissolving polyvinyl pyrrolidone in anhydrous ethanol at a material-liquid ratio of 1:15 g / ml.

[0051] S4. Add ammonia water and tetraethyl orthosilicate to the PMMA-Ag composite microsphere dispersion. The volume ratio of PMMA-Ag composite microsphere dispersion, ammonia water and tetraethyl orthosilicate is 50:3:1. Stir the reaction for 130 minutes. After suction filtration, rinsing and drying, PMMA-Ag-SiO2 composite microspheres are obtained.

[0052] S5. Calcine the PMMA-Ag-SiO2 composite microspheres at 535°C for 125 min to obtain silver-loaded microparticles.

[0053] The infrared spectra of the PMMA porous microspheres and carboxylated PMMA porous microspheres obtained in this example are shown in Figure 1 As shown in the PMMA porous microsphere spectrum, at 1725 cm -1 and 1630cm -1 Two characteristic absorption peaks appeared near 1630 cm-1, which were attributed to the C=O stretching vibration of the ester group and carboxyl group in the PMMA molecule. Compared with the infrared spectrum of PMMA porous microspheres, the carboxyl PMMA porous microspheres showed a strong absorption peak at 1630 cm-1. -1A stronger absorption peak than that of PMMA porous microspheres appeared at , which was attributed to the stretching vibration of C=O of carboxyl groups generated by PMMA porous microspheres after alkali treatment. The results showed that part of the ester groups of PMMA porous microspheres were converted into carboxyl groups, confirming the formation of carboxylated PMMA porous microspheres.

[0054] Example 4

[0055] An antibacterial nano silver colloidal solution comprises the following raw materials, measured by mass percentage: 0.3% silver nitrate, 0.1% glucose, 3% silver-carrying particles in Example 1, 2% polyvinyl pyrrolidone, 40% deionized water, and the balance is glycerol.

[0056] The method for preparing the antibacterial nano silver colloidal solution comprises the following steps:

[0057] (1) dissolving silver nitrate in deionized water to obtain a solution;

[0058] (2) mixing glucose, the silver-loaded particles in Example 1, polyvinyl pyrrolidone and glycerol to obtain a mixed solution;

[0059] (3) The dissolved solution and the mixed solution are combined and subjected to ultrasonic dispersion treatment to obtain an antibacterial nano-silver colloidal solution.

[0060] Example 5

[0061] An antibacterial nano silver colloidal solution comprises the following raw materials by mass percentage: 0.2% silver nitrate, 0.2% glucose, 1% silver-carrying particles in Example 2, 3% polyvinyl pyrrolidone, 30% deionized water, and the balance is glycerol.

[0062] The method for preparing the antibacterial nano silver colloidal solution comprises the following steps:

[0063] (1) dissolving silver nitrate in deionized water to obtain a solution;

[0064] (2) mixing glucose, the silver-loaded particles in Example 2, polyvinyl pyrrolidone and glycerol to obtain a mixed solution;

[0065] (3) The dissolved solution and the mixed solution are combined and subjected to ultrasonic dispersion treatment to obtain an antibacterial nano-silver colloidal solution.

[0066] Example 6

[0067] An antibacterial nano silver colloidal solution comprises the following raw materials, measured by mass percentage: 0.25% silver nitrate, 0.15% glucose, 2.2% silver-carrying particles in Example 3, 2.5% polyvinyl pyrrolidone, 35% deionized water, and the balance is glycerol.

[0068] The method for preparing the antibacterial nano silver colloidal solution comprises the following steps:

[0069] (1) dissolving silver nitrate in deionized water to obtain a solution;

[0070] (2) mixing glucose, the silver-loaded particles in Example 3, polyvinyl pyrrolidone and glycerol to obtain a mixed solution;

[0071] (3) The dissolved solution and the mixed solution are combined and subjected to ultrasonic dispersion treatment to obtain an antibacterial nano-silver colloidal solution.

[0072] Comparative Example 1

[0073] An antibacterial nano silver colloidal solution and a preparation method thereof are substantially the same as those in Example 6, except that the silver-carrying particles are prepared as follows:

[0074] S1, methyl methacrylate, divinylbenzene and azobisisobutyronitrile are stirred evenly, and then a polyvinyl alcohol aqueous solution with a mass concentration of 5% is added and mixed, and after the reaction is completed, the mixture is filtered, rinsed and dried to obtain PMMA microspheres;

[0075] The volume ratio of methyl methacrylate, divinylbenzene and polyvinyl alcohol aqueous solution is 20:1:180; the solid-liquid ratio of azobisisobutyronitrile and divinylbenzene is 1:2.5 g / ml.

[0076] Steps S2-S5, refer to the corresponding contents of Example 3, and finally obtain silver-loaded particles.

[0077] Comparative Example 2

[0078] An antibacterial nano silver colloidal solution and a preparation method thereof are substantially the same as those in Example 6, except that the silver-carrying particles are prepared as follows:

[0079] S1, methyl methacrylate, divinylbenzene, toluene and azobisisobutyronitrile are stirred evenly, and then a 5% polyvinyl alcohol aqueous solution is added to mix, and after the reaction is completed, sufficient ethanol is added to shake and dissolve the toluene, and the PMMA porous microspheres are obtained by suction filtration, washing and drying;

[0080] The volume ratio of methyl methacrylate, divinylbenzene, toluene and polyvinyl alcohol aqueous solution is 20:1:2:180; the solid-liquid ratio of azobisisobutyronitrile and divinylbenzene is 1:2.5 g / ml.

[0081] S2, dispersing PMMA porous microspheres in anhydrous ethanol at a material-liquid ratio of 5 mg / ml, then adding 0.05 mol / L silver nitrate solution to the obtained PMMA porous microsphere dispersion, stirring for the first time for 45 min, then adding polyvinyl pyrrolidone alcohol solution, stirring for the second time for 80 min, to obtain a PMMA-Ag composite microsphere dispersion;

[0082] The volume ratio of the PMMA porous microsphere dispersion, the silver nitrate solution and the polyvinyl pyrrolidone alcohol solution is 5:5:2. The polyvinyl pyrrolidone alcohol solution is prepared by dissolving polyvinyl pyrrolidone in anhydrous ethanol at a material-liquid ratio of 1:15 g / ml.

[0083] S3. Add ammonia water and tetraethyl orthosilicate to the PMMA-Ag composite microsphere dispersion. The volume ratio of PMMA-Ag composite microsphere dispersion, ammonia water and tetraethyl orthosilicate is 50:3:1. Stir the reaction for 130 minutes. After suction filtration, rinsing and drying, PMMA-Ag-SiO2 composite microspheres are obtained.

[0084] S4. Calcine the PMMA-Ag-SiO2 composite microspheres at 535°C for 125 min to obtain silver-loaded microparticles.

[0085] Comparative Example 3

[0086] An antibacterial nano silver colloidal solution comprises the following raw materials by mass percentage: 0.35% silver nitrate, 0.15% glucose, 2.5% polyvinyl pyrrolidone, 35% deionized water, and the balance is glycerol. The effect of the lack of silver content in the silver-carrying microparticles is compensated by increasing the content of silver nitrate.

[0087] The method for preparing the antibacterial nano silver colloidal solution comprises the following steps:

[0088] (1) dissolving silver nitrate in deionized water to obtain a solution;

[0089] (2) mixing glucose, polyvinyl pyrrolidone and glycerol to obtain a mixed solution;

[0090] (3) The dissolved solution and the mixed solution are combined and subjected to ultrasonic dispersion treatment to obtain an antibacterial nano-silver colloidal solution.

[0091] Comparative Example 4

[0092] An antibacterial nano silver colloidal solution comprises the following raw materials, measured by mass percentage: 0.25% of silver nitrate, 2.2% of the silver-carrying particles in Example 3, 2.5% of polyvinyl pyrrolidone, 35% of deionized water, and the balance of glycerol.

[0093] The method for preparing the antibacterial nano silver colloidal solution comprises the following steps:

[0094] (1) dissolving silver nitrate in deionized water to obtain a solution;

[0095] (2) mixing the silver-loaded particles, polyvinyl pyrrolidone and glycerol in Example 3 to obtain a mixed solution;

[0096] (3) The dissolved solution and the mixed solution are combined and subjected to ultrasonic dispersion treatment to obtain an antibacterial nano-silver colloidal solution.

[0097] Quality Inspection

[0098] 1. The antibacterial nano-silver colloidal solutions in Examples 4-6 and Comparative Examples 1-4 were used as samples for testing. The specific test results are shown in Table 1.

[0099] Immerse the pure cotton cloth in the corresponding sample, then take it out and dry it naturally. Perform the antibacterial performance test according to the standard of FZ / T 73024-2014, and record it as the initial antibacterial rate.

[0100] The pure cotton cloth was immersed in the corresponding sample, then taken out and dried naturally, and then immersed in deionized water. At 1 month and 6 months, the samples were taken out and dried, and the antibacterial performance was tested according to the standard of FZ / T 73024-2014, which was recorded as the persistent antibacterial rate.

[0101] Table 1 Antibacterial properties

[0102]

[0103] From the above table, we can see that:

[0104] (1) The long-lasting antibacterial rates of the samples of Comparative Examples 1 and 2 are not as good as those of Example 6, indicating that the multi-porous channel treatment and carboxylation treatment of PMMA microspheres increase the loading amount of nanosilver and have better sustained-release performance.

[0105] (2) The initial antibacterial rate of the sample in Comparative Example 3 is good, but the persistent antibacterial effect is far inferior to that of Example 6, indicating that the silver-loaded particles can indeed achieve the slow release of silver ions, prevent the large-scale loss of silver ions, and improve the persistence of antibacterial properties.

[0106] (3) The sample of Comparative Example 4 is not much different from that of Example 6. At the one-month time point, the persistent antibacterial rate is significantly lower than that of Example 6, indicating that the addition of glucose has a certain improvement effect on the antibacterial performance of the antibacterial nano-silver colloidal solution.

[0107] 2. The silver-loaded microparticles in Example 3, Comparative Example 1 and Comparative Example 2 were used as the objects to detect their silver ion sustained release performance. 0.2 g of silver-loaded microparticles were dispersed in 20 ml of deionized water and placed on a micro-oscillator to oscillate at a speed of 60 rpm to accelerate the release of silver ions. At multiple time points, the oscillated liquid was centrifuged to separate the supernatant, and the silver ion concentration in the supernatant was measured using an inductively coupled plasma mass spectrometer to determine its sustained release performance. The specific test results are as follows: Figure 2 shown.

[0108] from Figure 2 It can be seen that the maximum silver ion concentration in Example 3 is significantly higher than that in Comparative Example 1 and Comparative Example 2, indicating that the multi-porous treatment and carboxylation treatment of PMMA microspheres can indeed allow more nanosilver to be loaded in the microspheres; the silver-loaded particles in Comparative Example 1, Comparative Example 2 and Example 3 can continuously release silver ions and have a good sustained release effect.

[0109] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An antibacterial nano silver colloidal solution, characterized in that: The raw materials include the following in percentage by mass: 0.2-0.3% of silver nitrate, 0.1-0.2% of glucose, 1-3% of silver-carrying particles, 2-3% of polyvinyl pyrrolidone, 30-40% of deionized water, and the balance is glycerol.

2. The antibacterial nano silver colloidal solution according to claim 1, characterized in that: The preparation of the silver-loaded particles is as follows: S1, methyl methacrylate, divinylbenzene, toluene and azobisisobutyronitrile are stirred evenly, and then polyvinyl alcohol aqueous solution is added to mix, and after the reaction is completed, sufficient ethanol is added to shake and dissolve the toluene, and then filtered, rinsed and dried to obtain PMMA porous microspheres; S2, adding PMMA porous microspheres to a sodium hydroxide solution, and after the stirring reaction is completed, filtering, rinsing, and drying to obtain carboxylated PMMA porous microspheres; S3, dispersing the carboxylated PMMA porous microspheres in anhydrous ethanol, then adding a silver nitrate solution to the carboxylated PMMA porous microsphere dispersion, stirring for the first time, then adding a polyvinyl pyrrolidone alcohol solution, stirring for the second time, to obtain a PMMA-Ag composite microsphere dispersion; S4, adding ammonia water and tetraethyl orthosilicate to the PMMA-Ag composite microsphere dispersion to carry out stirring reaction, after the reaction is completed, filtering, rinsing and drying to obtain PMMA-Ag-SiO2 composite microspheres; S5. calcining the PMMA-Ag-SiO2 composite microspheres at high temperature to obtain silver-loaded microparticles.

3. The antibacterial nano silver colloidal solution according to claim 2, characterized in that: In step S1, the volume ratio of methyl methacrylate, divinylbenzene, toluene and polyvinyl alcohol aqueous solution is 20:1:2:180; the solid-liquid ratio of azobisisobutyronitrile and divinylbenzene is 1:2.5 g / ml; and the mass concentration of the polyvinyl alcohol aqueous solution is 5%.

4. The antibacterial nano silver colloidal solution according to claim 2, characterized in that: In step S2, the concentration of the sodium hydroxide solution is 0.2-0.4 mol / L; the stirring reaction temperature is 75-85° C., and the stirring reaction time is 2-4 h.

5. The antibacterial nano silver colloidal solution according to claim 2, characterized in that: In step S3, the solid-liquid ratio of the carboxylated PMMA porous microspheres and anhydrous ethanol is 5 mg / ml; the volume ratio of the carboxylated PMMA porous microsphere dispersion, the silver nitrate solution and the polyvinyl pyrrolidone alcohol solution is 5:5:2; and the concentration of the silver nitrate solution is 0.05 mol / L.

6. The antibacterial nano silver colloidal solution according to claim 2, characterized in that: In step S3, the polyvinyl pyrrolidone alcohol solution is prepared by dissolving polyvinyl pyrrolidone in anhydrous ethanol at a solid-liquid ratio of 1:15 g / ml.

7. The antibacterial nano silver colloidal solution according to claim 2, characterized in that: In step S3, the initial stirring time is 40-50 minutes, and the secondary stirring time is 70-90 minutes.

8. The antibacterial nano silver colloidal solution according to claim 2, characterized in that: In step S4, the volume ratio of the PMMA-Ag composite microsphere dispersion, ammonia water and tetraethyl orthosilicate is 50:3:1; and the stirring reaction time is 120-150 minutes.

9. The antibacterial nano silver colloidal solution according to claim 2, characterized in that: In step S5, the high temperature calcination temperature is 500-550°C, and the high temperature calcination time is 100-150 minutes.

10. The method for preparing the antibacterial nano silver colloidal solution according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) dissolving silver nitrate in deionized water to obtain a solution; (2) mixing glucose, silver-loaded particles, polyvinyl pyrrolidone and glycerol to obtain a mixed solution; (3) The dissolved solution and the mixed solution are combined and subjected to ultrasonic dispersion treatment to obtain an antibacterial nano-silver colloidal solution.

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