Preparation method of silver / graphene material

Abstract

The invention relates to a preparation method of a silver / graphene material, which comprises the following steps: 1, mixing a silver compound and graphene as a raw material, adding the raw material into a water-alcohol mixed solution, and carrying out ultrasonic dispersion to obtain a mixed solution; 2, carrying out irradiation treatment on the mixed solution by using an electron accelerator or a cobalt source; 3, carrying out centrifugal separation on the irradiated mixed solution, and cleaning to remove unreacted silver compounds and redundant solvents; and 4, drying the product to obtain the silver / graphene antibacterial material. According to the prepared silver / graphene antibacterial material, the antibacterial performance of graphene and the antibacterial performance of a silver compound are combined, and the antibacterial performance of the material is remarkably improved. The prepared silver / graphene antibacterial material has good high-temperature resistance and can be used under the high-temperature condition.

Description

Technical Field

[0001] The present invention relates to the preparation technology of antibacterial materials, specifically a preparation method of silver / graphene materials. Background Art

[0002] In recent years, graphene and its derivatives have become important research objects of new functional materials due to their excellent electrical conductivity, strength, chemical stability and biocompatibility. Especially, the oxygen functional groups rich on the surface of graphene endow it with high activity and good physicochemical properties, showing good application prospects in the fields of nanotechnology, sensors and antibacterial materials.

[0003] In the preparation of silver-attached graphene materials, although traditional synthesis methods such as chemical reduction method, solvothermal method and electrochemical method are effective, they often have problems such as complex operation, use of harmful chemical reagents and environmental pollution. In recent years, as a new type of green preparation technology, electron irradiation method has received extensive attention because it can directly initiate chemical reactions of materials without adding external chemical reagents. Through the irradiation of high-energy electron beams, the electron irradiation method can effectively control the accuracy and selectivity of the reaction, promote the reduction of silver particles and make them uniformly attached to the surface of graphene, thereby preparing silver-attached graphene composite materials with good antibacterial properties.

[0004] Existing technologies mostly prepare by photocatalytic reactions. For example, in CN201710534125.6, a method for stepwise photocatalytic preparation of SnO2-silver / graphene nanocomposite materials uses SnO2 as a photocatalyst. First, under nitrogen protection, silver nitrate is photocatalytically reduced to silver ions by ultraviolet-visible light irradiation to form a directionally grown SnO2-nanosilver heterostructure. Then, under nitrogen protection and stirring conditions, graphene oxide is photocatalytically reduced again by ultraviolet-visible light irradiation to obtain SnO2-silver / graphene nanocomposite materials. In the photocatalytic reactions of existing technologies, the reaction time is long, the reaction conditions are complex, the reaction process is not easy to control, and it is easy to cause uneven quality of the final products.

[0005] Therefore, the present invention proposes a method for preparing silver-attached graphene antibacterial materials based on the electron irradiation method, aiming to overcome the shortcomings of existing technologies, realize the uniform attachment of silver particles on the surface of graphene, improve the antibacterial performance of the materials, and avoid the use of harmful chemicals at the same time, providing a new idea and technical path for the green preparation of antibacterial materials. Summary of the Invention

[0006] Now, in order to solve the above technical problems, the present invention proposes a preparation method of silver / graphene materials. The technical problems to be solved by the present invention are realized by adopting the following technical solutions:

[0007] A preparation method of a silver / graphene material, the method comprising the following steps:

[0008] First step: A silver compound and graphene are mixed as raw materials and added to a water-alcohol mixed solution, and ultrasonic dispersion is carried out to obtain a mixed solution;

[0009] Second step: The mixed solution is irradiated with an electron accelerator or a cobalt source;

[0010] Third step: The irradiated mixed solution is centrifuged and separated, and unreacted silver compounds and excess solvents are removed by washing;

[0011] Fourth step: The product is dried to obtain a silver / graphene antibacterial material.

[0012] The silver compound is selected from one or more of silver nitrate, silver acetate, silver fluoride or silver sulfate, and the addition amount of silver element is 0.1%-5% of the mass of graphene.

[0013] The alcohol in the water-alcohol mixed solution is selected from one or more of isopropanol, n-propanol, ethanol or methanol, and the volume ratio of alcohol in the mixed solution is 1%-10%.

[0014] The graphene is selected from one or more of monolayer oxidized graphene, multilayer oxidized graphene, reduced monolayer oxidized graphene, reduced multilayer oxidized graphene or graphene quantum dots.

[0015] The mass ratio of graphene in the mixed solution is 0.1%-20%.

[0016] The irradiation dose of the electron accelerator or the cobalt source is 15 kGy - 200 kGy, and the power of the electron accelerator is 3 MeV - 20 MeV.

[0017] In the fourth step, the drying temperature is 50°C - 120°C, and the drying time is 4 h - 12 h until the moisture content of the silver / graphene material is lower than 3%.

[0018] The beneficial effects of the present invention are: The silver / graphene antibacterial material prepared by the present invention combines the antibacterial properties of graphene and silver compounds, significantly improving the antibacterial performance of the material.

[0019] The silver / graphene antibacterial material prepared by the present invention has good high-temperature resistance and can be used under high-temperature conditions.

[0020] The present invention adopts electron beam or γ-ray irradiation reduction, which is simple, efficient, and does not require the use of harmful chemical reagents, having environmental protection advantages. It is operated under normal temperature and pressure, saving energy and being easy to mass-produce.

[0021] It has wide adaptability, and various graphene (oxidized, reduced, quantum dots, etc.) can be selected; the process parameters (irradiation dose) are accurately controllable, and the quality is stable.

[0022] The silver / graphene antibacterial material prepared by the present invention is a composite material that not only has antibacterial properties but also has characteristics such as electrical conductivity, thermal conductivity, and mechanical strength.

[0023] Compared with the photocatalytic reaction, 1. The reaction time of the present invention is short, and only electron irradiation is required to complete the reaction within a few seconds. 2. The reaction conditions are simple, only standing under an electron accelerator or a cobalt source device is required, without stirring and heating, and it is carried out at room temperature. 3. The reaction and particle size are controllable, and the reaction process is controlled by controlling the irradiation dose, dose rate, etc. 4. The reaction principle is different. The electron beam or cobalt source generates hydrated electrons or H· radicals by initiating the decomposition of water to reduce Ag ions. Brief Description of the Drawings

[0024] The present invention will be further described below with reference to the drawings and embodiments.

[0025] Figure 1 It is the SEM image of the silver / graphene antibacterial material in the embodiment of the present invention;

[0026] Figure 2 It is the test result of the antibacterial performance of the silver / graphene antibacterial material in the embodiment of the present invention. Detailed Embodiments

[0027] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be described more clearly and completely below with reference to the drawings in the embodiments. Of course, the described embodiments are only a part of the present invention, not all of it. Based on this embodiment, other embodiments obtained by those skilled in the art without creative efforts are within the protection scope of the present invention.

[0028] The present invention includes the following embodiments:

[0029] Embodiment 1

[0030] 1 g of graphene and 0.15 g of silver nitrate were mixed and added to 100 g of water. 3 g of isopropanol was added dropwise, and after ultrasonic treatment for 30 min, irradiation treatment was carried out with an irradiation dose of 25 kGy. Subsequently, centrifugal filtration was carried out and washed 3 times to remove unreacted silver compounds and excess solvents. The filtered product was dried at 80 °C for 8 h to obtain the silver / graphene antibacterial material.

[0031] Embodiment 2

[0032] Mix 1 g of graphene and 0.2 g of silver nitrate, add them to 120 g of water, dropwise add 8 g of isopropanol, perform ultrasonic treatment for 30 min, and then perform irradiation treatment with an irradiation dose of 50 kGy. Subsequently, perform centrifugal filtration and wash 3 times to remove unreacted silver compounds and excess solvent. Dry the filtered product at 120 °C for 4 h to obtain a silver / graphene antibacterial material.

[0033] Example III

[0034] Mix 1 g of graphene and 0.4 g of silver nitrate, add them to 110 g of water, dropwise add 6 g of isopropanol, perform ultrasonic treatment for 30 min, and then perform irradiation treatment with an irradiation dose of 100 kGy. Subsequently, perform centrifugal filtration and wash 3 times to remove unreacted silver compounds and excess solvent. Dry the filtered product at 100 °C for 6 h to obtain a silver / graphene antibacterial material.

[0035] Example IV

[0036] Mix 1 g of graphene and 0.8 g of silver nitrate, add them to 50 g of water, dropwise add 5 g of isopropanol, perform ultrasonic treatment for 30 min, and then perform irradiation treatment with an irradiation dose of 200 kGy. Subsequently, perform centrifugal filtration and wash 3 times to remove unreacted silver compounds and excess solvent. Dry the filtered product at 100 °C for 6 h to obtain a silver / graphene antibacterial material.

[0037] Comparative Example

[0038] Mix 1 g of graphene and 0.4 g of silver nitrate, add them to 95 g of water, dropwise add 3 g of isopropanol, perform ultrasonic treatment for 30 min, and do not perform irradiation treatment. Subsequently, perform centrifugal filtration and wash 3 times to remove unreacted silver compounds and excess solvent. Dry the filtered product at 100 °C for 6 h to obtain a comparative sample.

[0039] Antibacterial Property Detection

[0040] As Figure 1 Shown are the scanning electron microscope pictures of Examples 1-4 and the comparative example, where (a) is Example I, (b) is Example II, (c) is Example III, (d) is Example IV, and (e) is the comparative example.

[0041] As Figure 2 Shown, using Escherichia coli as the test strain, the antibacterial properties of the materials prepared in Examples 1-4 and the comparative example were tested, where (a) is Example I, (b) is Example II, (c) is Example III, (d) is Example IV, and (e) is the comparative example.

[0042] The results show that the materials of Examples 1-4 all showed significant antibacterial effects at a concentration of 50 μg / mL, while the antibacterial performance of the comparative example was significantly poorer.

[0043] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification is only the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements fall within the scope of the present invention claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a silver / graphene material, characterized in that: The method comprises the following steps: The first step: adding a silver compound and graphene as raw materials into a water-alcohol mixture, and obtaining a mixed solution by ultrasonic dispersion; Step 2: irradiating the mixed solution with an electron accelerator or a cobalt source; Step 3: centrifuge the irradiated mixed solution to remove unreacted silver compounds and excess solvent; Step 4: Dry the product to obtain the silver / graphene antibacterial material.

2. The method for preparing the silver / graphene antibacterial material according to claim 1, characterized in that: The silver compound is selected from one or more of silver nitrate, silver acetate, silver fluoride or silver sulfate, and the added amount of the silver element is 0.1%-5% of the mass of the graphene.

3. The method for preparing the silver / graphene antibacterial material according to claim 1, characterized in that: The alcohol in the water-alcohol mixture is selected from one or more of isopropanol, n-propanol, ethanol or methanol, and the volume ratio of the alcohol in the mixture is 1%-10%.

4. The method for preparing the silver / graphene antibacterial material according to claim 1, characterized in that: The graphene is selected from one or more of oxidized single-layer graphene, oxidized multi-layer graphene, reduced single-layer oxidized graphene, reduced multi-layer oxidized graphene or graphene quantum dots.

5. The method for preparing the silver / graphene antibacterial material according to claim 1, characterized in that: The mass proportion of graphene in the mixed solution is 0.1%-20%.

6. The method for preparing the silver / graphene antibacterial material according to claim 1, characterized in that: The irradiation dose of the electron accelerator or the cobalt source is 15 kGy-200 kGy, and the power of the electron accelerator is 3 MeV-20 MeV.

7. The method for preparing the silver / graphene antibacterial material according to claim 1, characterized in that: In the fourth step, the drying temperature is 50° C.-120° C., and the drying time is 4 h-12 h, until the moisture content of the silver / graphene material is less than 3%.

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