A metal powder / graphene oxide nanocomposite, a silicone resin and a method for preparing the silicone resin

Abstract

The application discloses a metal powder / oxidized graphene nanocomposite, a silicone resin and a preparation method of the silicone resin. The metal powder / oxidized graphene nanocomposite is composed of metal powder and oxidized graphene, the mass ratio of the metal powder to the oxidized graphene is 100:1-1000:1, and the particle size of the metal powder is 100-1500 mesh. Through high-energy ray irradiation, the surface of the metal powder is adsorbed with the oxidized graphene, meanwhile, the viscosity of the doped silicone resin matrix is also improved, the dispersion of the metal powder in the silicone resin is improved through the cooperation of the two, and the shielding effect is improved.

Description

Technical Field

[0001] This invention relates to the field of composite materials technology. Specifically, it relates to a metal powder / graphene oxide nanocomposite material, an organosilicon resin, and a method for preparing the organosilicon resin. Background Technology

[0002] Organosilicon resins combine the properties of both inorganic and organic materials, possessing fundamental characteristics such as low surface tension, low viscosity-temperature coefficient, high compressibility, and high gas permeability. They also exhibit excellent properties including resistance to high and low temperatures, electrical insulation, oxidation stability, weather resistance, flame retardancy, hydrophobicity, and corrosion resistance. In nuclear facilities, organosilicon resins can be used as radiation-hardening encapsulation materials. However, to improve the shielding effect against high-energy radiation, a large amount of metal powder needs to be added to the organosilicon resin before use to increase its density and achieve the desired shielding effect. However, the low viscosity of organosilicon resins makes it easy for the added metal powder to settle, thus affecting the shielding effect.

[0003] To improve the dispersion ability of metal powders, existing technologies use silane coupling agents to treat the metal powders, as described in "Gao Jianping, Ge Peng. Preparation of tungsten / epoxy resin radiation protection composite materials and their in-situ tensile properties and microstructure evolution [J]. China Adhesives, 2020, 29(5):4." However, this method requires a separate chemical treatment of the metal powder, increasing the post-processing steps. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to provide a metal powder / graphene oxide nanocomposite material, an organosilicon resin, and a method for preparing the organosilicon resin. By irradiating with high-energy rays, graphene oxide is adsorbed on the surface of the metal powder. At the same time, the viscosity of the organosilicon resin matrix is ​​also increased after doping. The two work together to improve the dispersibility of the metal powder in the organosilicon resin, thereby improving the shielding effect.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] A metal powder / graphene oxide nanocomposite material is composed of metal powder and graphene oxide, wherein the mass ratio of metal powder to graphene oxide is 100:1 to 1000:1, and the particle size of the metal powder is 100 to 1500 mesh; the metal powder / graphene oxide nanocomposite material is prepared by the following steps:

[0007] S1) Disperse metal powder in a solvent to obtain a metal powder dispersion, wherein the dispersion amount is 1-1000g metal powder / 100-10000mL solvent;

[0008] S2) Add graphene oxide to the metal powder dispersion obtained in step S1), stir and ultrasonically disperse at 0-100℃ for 0.1-10 hours to obtain a metal powder / graphene oxide dispersion.

[0009] S3) Place the metal powder / graphene oxide dispersion obtained in step S2) into... 60 Irradiation in a Co radioactive source, with an absorbed dose of 1–1000 kGy;

[0010] S4) The metal powder / graphene oxide dispersion after step S3) is centrifuged to obtain a precipitate. The precipitate is then washed and centrifuged repeatedly 3 to 5 times. The precipitate is then dried to obtain the metal powder / graphene oxide nanocomposite material. The centrifuge speed for centrifuging the metal powder / graphene oxide dispersion is 10 to 1000 rpm.

[0011] The metal powder / graphene oxide nanocomposite material mentioned above uses metal powder selected from one or more of the following: iron powder, reduced iron powder, atomized iron powder, carbonyl iron powder, tungsten powder, tungsten oxide powder, lead powder, and lead oxide powder.

[0012] The aforementioned metal powder / graphene oxide nanocomposite material contains metal powder that is one or a mixture of carbonyl iron powder, tungsten powder, and lead oxide powder, with a particle size of 500 mesh to 1200 mesh.

[0013] The above-mentioned metal powder / graphene oxide nanocomposite material has a mass ratio of metal powder to graphene oxide of 200:1 to 500:1.

[0014] The solvent used in step S1) of the above-mentioned metal powder / graphene oxide nanocomposite material is one or a mixture of water, methanol, ethanol, 1-propanol, tetrahydrofuran, acetone, butanone, chloroform, dichloromethane, 1,2-dichloroethane, 1,1-dichloroethane, n-hexane, cyclohexane, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, ethyl acetate, and butyl acetate.

[0015] An organosilicon resin is composed of the following components: silicone oil, crosslinking agent, catalyst, and metal powder / graphene oxide nanocomposite material, wherein the mass ratio of the metal powder / graphene oxide nanocomposite material to the silicone oil is 4:1 to 0.1:1, the metal powder / graphene oxide nanocomposite material is the aforementioned metal powder / graphene oxide nanocomposite material, the mass ratio of the silicone oil to the crosslinking agent is 5:1 to 200:1, and the mass of the catalyst is 0.1% to 1% of the mass of the silicone oil.

[0016] The aforementioned organosilicon resin uses vinyl silicone oil as the silicone oil and hydrogen-containing silicone oil as the crosslinking agent. The viscosity of the hydrogen-containing silicone oil is 100–3000 mPa·s.

[0017] The above-mentioned organosilicon resin uses a platinum metal complex catalyst.

[0018] The preparation method of the above-mentioned organosilicon resin includes the following steps:

[0019] S10) Add the metal powder / graphene oxide nanocomposite material to the silicone oil and stir for 1 to 60 min to obtain mixture A; wherein the stirring speed is 10 to 2000 rpm and the mass ratio of nanocomposite material to silicone oil is 4:1 to 0.1:1.

[0020] S20) Add crosslinking agent and catalyst to mixture A obtained in step S10), and stir under vacuum for 1 to 60 min to obtain mixture B; wherein, the stirring speed is 10 to 2000 rpm, the mass ratio of silicone oil to crosslinking agent is 5:1 to 200:1, and the mass of catalyst is 0.1% to 1% of the mass of silicone oil.

[0021] S30) Pour the mixture B obtained in step S20) into a mold and cure it for 0.1 to 48 hours at a temperature of 0 to 100°C.

[0022] In the above preparation method, the curing time in step S30) is 1 to 12 hours, and the curing temperature is 20 to 60°C.

[0023] The technical solution of the present invention achieves the following beneficial technical effects:

[0024] This invention uses radiation technology to adsorb graphene oxide onto the surface of metal powder, enabling the metal powder to be stably dispersed in an organosilicon resin matrix. Without post-processing, the metal powder can be dispersed relatively uniformly in the organosilicon resin matrix, improving the consistency of the shielding performance of the organosilicon resin and avoiding weak points in the shielding of shielding components made of organosilicon resin. Attached Figure Description

[0025] Figure 1 The image shows the XRD pattern of the carbonyl iron powder / graphene oxide nanocomposite material prepared in Example 1. Detailed Implementation

[0026] Example 1

[0027] 50g of 500-mesh carbonyl iron powder was dispersed in 2500mL of water and stirred at 20℃ for 0.5 hours. 0.5g of graphene oxide was added to the carbonyl iron powder dispersion, and the mixture was stirred and ultrasonically dispersed at 20℃ for 0.5 hours. The carbonyl iron powder / graphene oxide dispersion was then placed in… 60Irradiated with a Co radioactive source for a certain period of time, with an absorbed dose of 500 kGy. After irradiation, the product was centrifuged at 500 rpm. The precipitate was washed and centrifuged repeatedly three times, then dried. 40 g of the dried precipitate was added to 20 g of vinyl silicone oil with a viscosity of 5000 mPa·s and stirred for 30 minutes to obtain mixture A1 at 500 rpm. Then, 4 g of hydrogen-containing silicone oil with a viscosity of 500 mPa·s and 0.2 g of platinum catalyst were added to mixture A1, and the mixture was vacuum stirred for 10 minutes to obtain mixture B1 at 500 rpm. Mixture B1 was poured into a mold and cured at 60°C for 12 hours. The precipitate is the carbonyl iron powder / graphene oxide nanocomposite material. The XRD pattern of the prepared carbonyl iron powder / graphene oxide nanocomposite material is shown below. Figure 1 As shown.

[0028] Comparative Example 1

[0029] 40g of 500-mesh carbonyl iron powder was added to 20g of vinyl silicone oil with a viscosity of 5000mPa·s. After stirring for 30 minutes, mixture a1 was obtained at a stirring speed of 500 rpm. Then, 4g of hydrogen-containing silicone oil with a viscosity of 500mPa·s and 0.2g of platinum catalyst were added to mixture a1. After vacuum stirring for 10 minutes, mixture b1 was obtained at a stirring speed of 500 rpm. Mixture b1 was poured into a mold and cured at 60℃ for 12 hours.

[0030] Example 2

[0031] 500g of 1200-mesh tungsten powder was dispersed in 5000mL of ethanol and stirred at 60℃ for 5 hours. 0.5g of graphene oxide was added to the tungsten powder dispersion and stirred and ultrasonically dispersed at 60℃ for 5 hours. The tungsten powder / graphene oxide dispersion was then placed in… 60 Irradiated with a Co radioactive source for a certain period of time, with an absorbed dose of 10 kGy. After irradiation, the product was centrifuged at 100 rpm. The precipitate was washed and centrifuged repeatedly three times, then dried. 100 g of the dried precipitate was added to 200 g of vinyl silicone oil with a viscosity of 1000 mPa·s and stirred for 10 minutes to obtain mixture A2 at 1000 rpm. Then, 2 g of hydrogen-containing silicone oil with a viscosity of 2000 mPa·s and 2 g of platinum catalyst were added to mixture A2, and the mixture was stirred under vacuum for 30 minutes to obtain mixture B2 at 1000 rpm. Mixture B2 was poured into a mold and cured at 20°C for 1 hour.

[0032] Comparative Example 2

[0033] 100g of 1200-mesh tungsten powder was added to 200g of vinyl silicone oil with a viscosity of 1000mPa·s. After stirring for 10 minutes, mixture a2 was obtained. The stirring speed was 1000 rpm. Then, 2g of hydrogen-containing silicone oil with a viscosity of 2000mPa·s and 2g of platinum catalyst were added to mixture a2. After vacuum stirring for 30 minutes, mixture b2 was obtained. Mixture b2 was poured into a mold and cured at 20°C for 1 hour.

[0034] Example 3

[0035] 500g of 1000-mesh lead powder was dispersed in 10000mL of tetrahydrofuran and stirred at 30℃ for 2 hours. 5g of graphene oxide was added to the lead powder dispersion and stirred and ultrasonically dispersed at 30℃ for 1 hour. The lead powder / graphene oxide dispersion was then placed in… 60 Irradiated with a Co radioactive source for a certain period of time, with an absorbed dose of 100 kGy. After irradiation, the product was centrifuged at 300 rpm. The precipitate was washed and centrifuged repeatedly three times, then dried. 500 g of the dried precipitate was added to 300 g of vinyl silicone oil with a viscosity of 3000 mPa·s and stirred for 30 minutes to obtain mixture A3 at 800 rpm. Then, 20 g of hydrogen-containing silicone oil with a viscosity of 1000 mPa·s and 4 g of platinum catalyst were added to mixture A3, and the mixture was stirred under vacuum for 30 minutes to obtain mixture B3 at 8000 rpm. Mixture B3 was poured into a mold and cured at 40°C for 6 hours.

[0036] Comparative Example 3

[0037] 500g of 1000-mesh lead powder was added to 300g of vinyl silicone oil with a viscosity of 3000mPa·s. After stirring for 30 minutes, mixture a3 was obtained at a stirring speed of 800 rpm. Then, 20g of hydrogen-containing silicone oil with a viscosity of 1000mPa·s and 4g of platinum catalyst were added to mixture a3. After vacuum stirring for 30 minutes, mixture b3 was obtained at a speed of 8000 rpm. Mixture b3 was poured into a mold and cured at 40℃ for 6 hours.

[0038] The cured samples prepared in Examples 1, 2, 3, Comparative Examples 1, 2, and 3 were each divided into three parts for tensile strength testing according to national standard GB / T 528-2009 and shielding coefficient testing according to Q / CYSXY001-2016. The test results are shown in Table 1.

[0039] Table 1. Performance test results of the silicone resins prepared in Examples 1-3 and Comparative Examples 1-3

[0040] sample Tensile strength (MPa) gamma-ray shielding coefficient Example 1-1 1.53 2.0 Examples 1-2 1.55 2.2 Examples 1-3 1.51 2.1 Comparative Example 1-1 0.82 1.2 Comparative Examples 1-2 0.62 0.8 Comparative Examples 1-3 0.76 1.0 Example 2-1 1.13 2.3 Example 2-2 1.05 2.2 Example 2-3 1.23 2.3 Comparative Example 2-1 0.75 1.1 Comparative Example 2-2 0.56 1.5 Comparative Examples 2-3 0.91 1.3 Example 3-1 1.38 2.1 Example 3-2 1.25 2.2 Example 3-3 1.30 2.1 Comparative Example 3-1 0.83 1.2 Comparative Example 3-2 0.64 1.4 Comparative Example 3-3 0.51 1.1

[0041] As shown in Table 1, the organosilicon resins prepared in Comparative Examples 1-3 were all prepared by directly adding metal powder into the organosilicon resin matrix. The metal powder is prone to agglomeration and sedimentation to varying degrees, which leads to significant differences in the gamma-ray shielding coefficient and mechanical properties of different parts of the organosilicon resin materials prepared in Comparative Examples 1-3. The shielding coefficient is low and the mechanical properties are poor. In contrast, in Examples 1-3, graphene oxide was first adsorbed onto the metal powder and irradiated. Then, the metal powder / graphene oxide nanocomposite material was added to the organosilicon resin matrix to form organosilicon resin. This treatment can effectively improve the dispersibility of metal powder in organosilicon resin, thereby improving the gamma-ray shielding coefficient and mechanical properties. It also ensures that the gamma-ray shielding coefficient and mechanical properties of different parts of the organosilicon resin materials prepared in Examples 1-3 are relatively similar, that is, it ensures the uniformity of the material.

[0042] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. A metal powder / graphene oxide nanocomposite, characterized by, The metal powder and graphene oxide are mixed in a mass ratio of 200:1 to 500:1, and the particle size of the metal powder is 100 to 1500 mesh; the metal powder / graphene oxide nanocomposite is prepared by the following steps: S1) dispersing the metal powder in a solvent to obtain a metal powder dispersion, wherein the dispersion amount is 1 to 1000 g of metal powder per 100 to 10000 mL of solvent, and the solvent is water; S2) adding graphene oxide to the metal powder dispersion obtained in step S1), stirring at 0 to 100℃ and ultrasonic dispersion for 0.1 to 10 hours to obtain a metal powder / graphene oxide dispersion; S3) The metal powder / graphene oxide dispersion liquid prepared in step S2) is subjected to 60 irradiation in a Co radiation source at an absorbed dose of 1 to 1000 kGy; S4) centrifugal treatment is performed on the metal powder / graphene oxide dispersion treated in step S3) to obtain a precipitate, then the precipitate is washed and centrifugally treated repeatedly for 3 to 5 times, and then the precipitate is dried to obtain the metal powder / graphene oxide nanocomposite; wherein the centrifugal speed of the metal powder / graphene oxide dispersion is 10 to 1000 rpm.

2. The metal powder / graphene oxide nanocomposite of claim 1, wherein the graphene oxide is present in an amount of 0.1 to 10 wt%. The metal powder is selected from one or a mixture of more than one of iron powder, reduced iron powder, atomized iron powder, carbonyl iron powder, tungsten powder, tungsten oxide powder, lead powder and lead oxide powder.

3. The metal powder / graphene oxide nanocomposite of claim 1, wherein the graphene oxide is present in an amount of 0.1 to 10 wt%. The metal powder is a mixture of one or more than one of carbonyl iron powder, tungsten powder and lead oxide powder, and the particle size of the metal powder is 500 to 1200 mesh.

4. A silicone resin characterized by, The metal powder / graphene oxide nanocomposite and the silicone oil are mixed in a mass ratio of 4:1 to 0.1:1, the metal powder / graphene oxide nanocomposite is the metal powder / graphene oxide nanocomposite described in claim 1, the silicone oil and the crosslinking agent are mixed in a mass ratio of 5:1 to 200:1, and the mass of the catalyst is 0.1 to 1% of the mass of the silicone oil.

5. The silicone resin according to claim 4, characterized in that, The silicone oil is vinyl silicone oil, and the crosslinking agent is hydrogen-containing silicone oil with a viscosity of 100 to 3000 mPa·s.

6. The silicone resin according to claim 4, characterized in that, The catalyst is a platinum metal complex catalyst.

7. The method of making a silicone resin of claim 4, characterized in that, The method comprises the following steps: S10) adding the metal powder / graphene oxide nanocomposite into the silicone oil and stirring for 1 to 60 minutes to obtain a mixture A; wherein the stirring speed is 10 to 2000 rpm, and the mass ratio of the nanocomposite to the silicone oil is 4:1 to 0.1:1; S20) adding the crosslinking agent and the catalyst into the mixture A obtained in step S10) and stirring for 1 to 60 minutes under vacuum to obtain a mixture B; wherein the stirring speed is 10 to 2000 rpm, the mass ratio of the silicone oil to the crosslinking agent is 5:1 to 200:1, and the mass of the catalyst is 0.1 to 1% of the mass of the silicone oil; S30) pouring the mixture B obtained in step S20) into a mold for curing and molding, and curing for 0.1 to 48 hours at a curing temperature of 0 to 100℃.

8. The preparation method according to claim 7, characterized in that, The curing time in step S30) is 1 to 12 hours, and the curing temperature is 20 to 60℃.

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