SiO2 / C composite material and preparation method and application thereof

Abstract

The invention belongs to the technical field of functional fillers, and discloses a SiO2 / C composite material as well as a preparation method and application thereof. The preparation method comprises the following steps: mixing an edible fungus cultivation body with porous silicon dioxide to obtain a silicon dioxide composite edible fungus cultivation body; mixing the silicon dioxide composite edible mushroom culture body with edible mushrooms, and culturing the edible mushrooms; after culture is completed, the edible mushrooms are removed, and waste cultivated bodies are reserved; and carbonizing the waste cultivated body, and sequentially crushing and screening to obtain the SiO2 / C composite material. The SiO2 phase and the biomass carbon phase in the SiO2 / C composite material are uniformly distributed, and the SiO2 / C composite material has the characteristics of difficult agglomeration and good dispersibility, and is suitable for being used as a rubber functional filler; meanwhile, the low-heat-generation performance is good when the diphase functional filler is used as a rubber filler, and the defect that the low-heat-generation performance of an existing diphase functional filler is not solved is overcome.

Description

Technical Field

[0001] The present invention relates to the technical field of functional fillers, and in particular to a SiO2 / C composite material and a preparation method and application thereof. Background Art

[0002] Filler is one of the main raw materials in the rubber industry and can give rubber a variety of excellent properties. Among the fillers used, silica and carbon black are the two most important and largest fillers in rubber materials. Among them, silica reinforced rubber has the advantages of low heat generation and good insulation; carbon black reinforced rubber can greatly increase the wear resistance and tear resistance of rubber materials. Since silica and carbon black each have their own advantages, in order to obtain better comprehensive performance, people usually compound silica and carbon materials, thus producing silicon-carbon dual-phase fillers.

[0003] In order to prepare silicon-carbon dual-phase fillers, researchers have made a lot of research on the composite method of silicon dioxide and carbon materials. At present, most silicon-carbon dual-phase fillers inevitably introduce organic solvents or use high-temperature methods during the preparation process, which is not friendly to the environment and consumes a lot of energy. For the selection of carbon sources, petroleum raw materials are inevitably used in some preparation methods. At the same time, the reinforcement effect of fillers in rubber reinforcement is fully discussed, but the problem of low heat generation performance of fillers is rarely solved. For example, the Chinese invention patent application with publication number CN106519301A discloses a method for preparing a SiO2 / helical nano-carbon fiber dual-phase filler, which uses polyacrylic acid, dicyclohexylcarbodiimide, dimethylaminopyridine and other organic solvents to graft spiral nanofibers to obtain SiO2-helical nano-carbon fiber dual-phase filler. However, the above scheme adds a large amount of organic solvents during the preparation process, which is not friendly to the environment, and only the rubber reinforcement function is tested, and the low heat generation performance of the filler has not yet been solved.

[0004] The Chinese invention patent application with publication number CN112080161A discloses a process for preparing dual-phase carbon black, the main steps of which are: reducing the moisture content of the raw oil to below 2%, mixing the raw oil with the combustion airflow in a reactor at a temperature greater than 1500°C; using high-speed jet technology, mixing silica powder with process water and spraying it into the carbon black reactor to form dual-phase carbon black. However, the above scheme ultimately requires filtering, collecting and separating the flue gas and exhaust gas, and the preparation process is energy-intensive, and requires the use of petroleum raw materials, which consumes a large amount of non-renewable resources.

[0005] The Chinese invention patent application with publication number CN116948429A discloses a preparation method and application of coal gasification slag-based carbon-silicon dual-phase filler. In the preparation process, the coal gasification slag is mixed with acid, placed in a reactor for hydrothermal reaction, and the obtained product is mixed with a rubber accelerator to obtain a coal gasification slag-based carbon-silicon dual-phase filler, thereby realizing the waste utilization of coal gasification slag. However, the above preparation process involves an acidic solvent and does not solve the low heat generation performance of the filler.

[0006] The Chinese invention patent application with publication number CN107200332A discloses a method for preparing nano-silicon dioxide, which uses acid, alkali and fermentation to modify the surface of cotton straw fiber filaments, then carbonizes the fiber filaments, and then dopamine undergoes self-polymerization and cross-linking reaction under the action of dissolved oxygen in water, forming a dopamine layer on the surface of the carbonized fiber powder to make a modified template, dehydrating silica at high temperature to generate silicon dioxide deposited on the surface of the template, and finally calcining to remove the template. However, the above material does not belong to silicon-carbon dual-phase material and has not been actually applied in rubber for testing. Summary of the invention

[0007] The purpose of the present invention is to provide a SiO2 / C composite material and a preparation method and application thereof, so as to solve the problem of low heat generation performance that the existing dual-phase filler has not solved, and at the same time realize the green preparation of SiO2 / C dual-phase filler.

[0008] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0009] The present invention provides a method for preparing a SiO2 / C composite material, comprising the following steps:

[0010] (1) mixing the edible fungus cultivation body with porous silica to obtain a silica composite edible fungus cultivation body;

[0011] The silicon dioxide composite edible fungus cultivation body is mixed with edible fungi to culture the edible fungi; after the culture is completed, the edible fungi are removed and the discarded cultivation body is retained;

[0012] (2) Carbonizing the discarded culture medium in step (1) to obtain a SiO2 / C composite material.

[0013] Preferably, in the preparation method, the porous silica in step (1) includes one or more of silica powder, carbon monoxide, diatomaceous earth, diatom shale, opal, zeolite and montmorillonite.

[0014] Preferably, in the preparation method, the particle size of the porous silica in step (1) is 500 nm to 100 μm, and the specific surface area is 60 to 500 m 2 / g, pore size is 2~100nm, porosity is 0.1~5cm 3 / g.

[0015] Preferably, in the preparation method, the mass ratio of the porous silica to the edible fungus cultivation body in step (1) is 1:1-10.

[0016] Preferably, in the preparation method, the time to complete the cultivation in step (1) is ≥ 3 months.

[0017] Preferably, in the preparation method, in step (2), the carbonization is carried out under a protective atmosphere, and the protective atmosphere is at least one of nitrogen or argon; the carbonization temperature is 600-950°C, the time is 10-60 min, and the rate of heating to the desired carbonization temperature is 5-15°C / min.

[0018] Preferably, in the preparation method, after the carbonization in step (2), the further steps include: crushing and screening in sequence.

[0019] Preferably, in the preparation method, the crushing speed is 300-700 rpm, the time is 15-60 min; the particle size D of the sieving is 50 =500nm~45μm.

[0020] The invention also provides a SiO2 / C composite material prepared by the preparation method.

[0021] The present invention also provides an application of a SiO2 / C composite material in rubber. The amount of the SiO2 / C composite material is 5 to 80 phr based on 100 phr of rubber. The rubber is natural rubber or synthetic rubber. The synthetic rubber is butadiene rubber or styrene-butadiene rubber.

[0022] It can be seen from the above technical solution that compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The present invention uses discarded edible fungus cultivation bodies as carbon sources and ferments them. At the same time, micron-sized silica particles containing abundant nanopores are introduced when preparing the edible fungus cultivation bodies. The porous structure can provide a large number of attachment sites for the uniform attachment of fungal microorganisms, and provide a good temperature and humidity growth environment for fungal microorganisms, which is conducive to the rapid growth of fungal microorganisms. Since fungal microorganisms exchange organic matter with the surrounding edible fungus cultivation bodies during growth, the starch, polysaccharides, proteins, esters and other components in the edible fungus cultivation bodies are effectively utilized, so that the fungal microorganisms and the porous structure of silica form a microscopic, mesoscopic, and macroscopic three-dimensional mycelial structure (such as Figure 1As shown in the figure, a large number of attachment sites are provided for the dispersion of biomass carbon on SiO2, which helps to form the distribution of biomass carbon structure at the molecular level and realize the organic combination of biomass carbon and porous SiO2. After picking mature edible fungi, the discarded silica composite edible fungi culture body is carbonized to promote the dehydration and condensation of the biomass carbon structure in the culture body, remove the internal hydrogen and oxygen elements, and form nano-scale holes at the original position, forming a SiO2 / C composite material with good structural properties. Therefore, the biomass carbon source in the silica composite edible fungi culture body forms a natural microscopic porous structure after multiple interactions with the microbial flora, and can become the best source for constructing an ideal SiO2 / C composite material after being compounded with SiO2 and fermented again.

[0024] (2) The SiO2 in the preparation method of the present invention is derived from minerals, and the carbon is derived from biomass. Compared with the method in which the carbon source is derived from petroleum and chemical organic synthesis, it is more environmentally friendly and effectively utilizes the discarded edible fungus culture body, solves the problems of high energy consumption and environmental unfriendliness in the preparation process of the prior art, and realizes the green preparation of SiO2 / C composite materials.

[0025] (3) The present invention can make up for the lack of biomass silicon in the edible fungus cultivation body by adding different proportions of micron-sized porous silica to the edible fungus cultivation body, while achieving controllable ratio of carbon to silica in the SiO2 / C composite material.

[0026] (4) The present invention carbonizes the biomass carbon source of the three-dimensional mycelium structure attached to the porous site of SiO2, and the obtained SiO2 / C composite material has a uniform distribution of SiO2 phase and biomass carbon phase, has the characteristics of not easy to agglomerate and good dispersibility, and is suitable for use as a rubber functional filler. At the same time, the prepared SiO2 / C composite material has good low heat generation performance when used as a rubber filler, which makes up for the defect that the existing dual-phase functional filler does not solve the low heat generation performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the description of the embodiments or the prior art are briefly introduced below.

[0028] Figure 1 It is a three-dimensional mycelium structure of porous silica and fungal microorganisms;

[0029] Figure 2 This is the SEM image of product 1;

[0030] Figure 3 are the EDS spectra of products 1 to 3, where a is product 1, b is product 2, and c is product 3;

[0031] Figure 4This is a comparison curve of the low heat generation performance of products 1 to 3 and N330 carbon black in functionalized rubber. DETAILED DESCRIPTION

[0032] The present invention provides a method for preparing a SiO2 / C composite material, comprising the following steps:

[0033] (1) mixing the edible fungus cultivation body with porous silica to obtain a silica composite edible fungus cultivation body;

[0034] The silicon dioxide composite edible fungus cultivation body is mixed with edible fungi to culture the edible fungi; after the culture is completed, the edible fungi are removed and the discarded cultivation body is retained;

[0035] (2) Carbonizing the discarded culture medium in step (1) to obtain a SiO2 / C composite material.

[0036] In the present invention, the edible fungus culture medium in step (1) preferably includes a biomass carbon source, which includes but is not limited to one or more of cottonseed hulls, corn cobs, leaf and wood chips, bean straw powder, wheat straw powder, peanut shells, bran and rice bran.

[0037] In the present invention, the source of the edible fungus culture medium in step (1) is not limited, and commercially available or non-commercially available products known to those skilled in the art may be used.

[0038] In the present invention, the porous silica in step (1) preferably includes one or more of silica powder, carbon monoxide, diatomaceous earth, diatom shale, opal, zeolite and montmorillonite, and further preferably includes silica powder, diatomaceous earth, diatom shale, opal, zeolite or montmorillonite, and more preferably silica powder.

[0039] In the present invention, the brand of the carbon is preferably TSI-A5008.

[0040] In the present invention, the particle size of the porous silica in step (1) is preferably 500 nm to 100 μm, more preferably 500 nm to 50 μm, and more preferably 500 nm to 10 μm; the specific surface area is preferably 60 to 500 m 2 / g, more preferably 60 to 300 m 2 / g, more preferably 60 to 200 m 2 / g; the pore size is preferably 2 to 100 nm; the porosity is preferably 0.1 to 5 cm 3 / g, more preferably 0.1 to 3 cm 3 / g, more preferably 0.1 to 2 cm 3 / g.

[0041] In the present invention, the mass ratio of the porous silica to the edible fungus culture medium in step (1) is preferably 1:1-10, more preferably 1:2-4, and even more preferably 1:2.

[0042] In the present invention, the step (1) preferably further comprises: sterilizing the silica composite edible fungus cultivation body before mixing the silica composite edible fungus cultivation body with the edible fungus.

[0043] In the present invention, the conditions for the sterilization treatment are not limited, and a method familiar to those skilled in the art can be used. Specifically, in the embodiment of the present invention, the sterilization treatment is carried out at 120° C. for 1.5 h or more.

[0044] In the present invention, the edible fungi in step (1) preferably include but are not limited to shiitake mushrooms, oyster mushrooms or black fungus. Preferably, the embodiment of the present invention takes black fungus as an example for cultivation.

[0045] In the present invention, the time to complete the culture in step (1) is preferably ≥3 months, more preferably ≥3.5 months, and more preferably 4 months.

[0046] In the present invention, step (2) preferably further comprises: naturally drying the waste culture medium of step (1) before the carbonization. The natural drying time is preferably 5 to 24 hours, more preferably 12 to 24 hours, and more preferably 24 hours.

[0047] In the present invention, the equipment used for the carbonization in step (2) is preferably a carbonization furnace.

[0048] In the present invention, in step (2), the carbonization is preferably carried out under a protective atmosphere; the protective atmosphere is preferably at least one of nitrogen or argon, more preferably nitrogen or argon, and more preferably nitrogen.

[0049] In the present invention, in step (2), the carbonization temperature is preferably 600-950°C, more preferably 700-900°C, and more preferably 800°C; the time is preferably 10-60 min, more preferably 30-60 min, and more preferably 60 min; the rate of heating to the desired carbonization temperature is preferably 5-15°C / min, more preferably 5-10°C / min, and more preferably 5°C / min.

[0050] In the present invention, the carbonization in step (2) preferably further comprises: crushing and screening in sequence.

[0051] In the present invention, the crushing equipment is preferably a planetary ball mill.

[0052] In the present invention, the crushing rotation speed in step (2) is preferably 300-700 rpm, more preferably 400-600 rpm, and more preferably 500 rpm; the time is preferably 15-60 min, more preferably 20-40 min, and more preferably 30 min.

[0053] In the present invention, the screening equipment is preferably a centrifugal classifier.

[0054] In the present invention, the particle size D of the screening in step (2) is 50 It is preferably 500 nm to 45 μm, more preferably 500 nm to 20 μm, and still more preferably 500 nm to 10 μm.

[0055] The invention also provides a SiO2 / C composite material prepared by the preparation method.

[0056] In the present invention, the average particle size of the SiO2 / C composite material is preferably 500nm to 10μm, more preferably 800nm ​​to 5μm, and more preferably 1 to 3μm; the porosity is preferably 0.1 to 2cm 3 / g, more preferably 0.1 to 0.8 cm 3 / g, more preferably 0.15 to 0.3 cm 3 / g; the average pore size is preferably 0.5 to 100 nm, more preferably 1 to 40 nm, and more preferably 5 to 20 nm; the specific surface area is preferably 30 to 200 m 2 / g, more preferably 40 to 150 m 2 / g, more preferably 50 to 100 m 2 / g.

[0057] The invention also provides an application of the SiO2 / C composite material in rubber.

[0058] In the present invention, in the application method, based on 100 phr of rubber, the amount of the SiO2 / C composite material is preferably 5 to 80 phr, more preferably 15 to 40 phr, and more preferably 30 phr.

[0059] In the present invention, the rubber is preferably natural rubber or synthetic rubber, more preferably natural rubber; the synthetic rubber is preferably butadiene rubber or styrene-butadiene rubber, more preferably butadiene rubber.

[0060] In the present invention, other conditions in the application method are not limited, and schemes familiar to those skilled in the art can be adopted.

[0061] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0062] Example 1

[0063] This embodiment provides a method for preparing a SiO2 / C composite material, comprising the following steps:

[0064] (1) 2 kg of Auricularia auricula culture (from the Science and Technology Demonstration Park of Dongjingcheng Forestry Bureau, Heilongjiang) and 200 g of silica powder (D 50 -8μm, model TSI-1, manufacturer is Harbin Silicon New Materials Co., Ltd., particle size is 500nm~10μm, specific surface area is 60~200m 2 / g, pore size is 2~100nm, porosity is 0.1~2cm 3 / g) and evenly mixed to obtain a silicon dioxide composite edible fungus culture body;

[0065] After sterilizing the silica composite edible fungus culture body at 120° C. for 1.5 h, inoculating the auricularia auricula into the silica composite edible fungus culture body for cultivation, and after the auricularia auricula has been cultivated for 3 months, removing the mature auricularia auricula and retaining the discarded culture body;

[0066] (2) The waste culture medium of step (1) was naturally dried for 24 hours, and then the waste culture medium was placed in a carbonization furnace, and the temperature was raised to 800°C at a heating rate of 5°C / min under nitrogen protection for carbonization for 60 minutes; the obtained silicon-carbon composite was ball-milled in a planetary ball mill at a speed of 500 rpm for 30 minutes, and then the ball-milled sample was sieved by a centrifugal classifier to obtain a particle size D 50 The sample with a particle size of ≤3 μm was used to obtain a SiO2 / C composite material, which was recorded as Product 1.

[0067] Example 2

[0068] This embodiment provides a method for preparing a SiO2 / C composite material, comprising the following steps:

[0069] (1) 2 kg of Auricularia auricula culture (from the Science and Technology Demonstration Park of Dongjingcheng Forestry Bureau, Heilongjiang) and 500 g of silica powder (D 50 -8μm, model TSI-1, manufacturer is Harbin Silicon New Materials Co., Ltd., particle size is 500nm~10μm, specific surface area is 60~200m 2 / g, pore size is 2~100nm, porosity is 0.1~2cm 3 / g) and evenly mixed to obtain a silicon dioxide composite edible fungus culture body;

[0070] After sterilizing the silica composite edible fungus culture body at 120° C. for 1.5 h, inoculating the auricularia auricula into the silica composite edible fungus culture body for cultivation, and after the auricularia auricula has been cultivated for 3 months, removing the mature auricularia auricula and retaining the discarded culture body;

[0071] (2) The waste culture medium of step (1) was naturally dried for 24 hours, and then the waste culture medium was placed in a carbonization furnace, and the temperature was raised to 800°C at a heating rate of 5°C / min under nitrogen protection for carbonization for 60 minutes; the obtained silicon-carbon composite was ball-milled in a planetary ball mill at a speed of 500 rpm for 30 minutes, and then the ball-milled sample was sieved by a centrifugal classifier to obtain a particle size D 50 For samples with a particle size of ≤3 μm, a SiO2 / C composite material was obtained, which was recorded as Product 2.

[0072] Example 3

[0073] This embodiment provides a method for preparing a SiO2 / C composite material, comprising the following steps:

[0074] (1) 2 kg of Auricularia auricula culture (from the Science and Technology Demonstration Park of Dongjingcheng Forestry Bureau, Heilongjiang) and 1000 g of silica powder (D 50 -8μm, model TSI-1, manufacturer is Harbin Silicon New Materials Co., Ltd., particle size is 500nm~10μm, specific surface area is 60~200m 2 / g, pore size is 2~100nm, porosity is 0.1~2cm 3 / g) and evenly mixed to obtain a silicon dioxide composite edible fungus culture body;

[0075] After sterilizing the silica composite edible fungus culture body at 120° C. for 1.5 h, inoculating the auricularia auricula into the silica composite edible fungus culture body for cultivation, and after the auricularia auricula has been cultivated for 4 months, removing the mature auricularia auricula and retaining the discarded culture body;

[0076] (2) The waste culture medium of step (1) was naturally dried for 24 hours, and then the waste culture medium was placed in a carbonization furnace, and the temperature was raised to 800°C at a heating rate of 5°C / min under nitrogen protection for carbonization for 60 minutes; the obtained silicon-carbon composite was ball-milled in a planetary ball mill at a speed of 500 rpm for 30 minutes, and then the ball-milled sample was sieved by a centrifugal classifier to obtain a particle size D 50 For samples with a particle size of ≤3 μm, a SiO2 / C composite material was obtained, which was recorded as product 3.

[0077] The particle size, porosity, average pore size and specific surface area of ​​products 1 to 3 were tested, and the results are shown in Table 1.

[0078] Table 1. Characteristic properties of products 1 to 3

[0079] Characteristic properties Product 1 Product 2 Product 3 Average particle size (μm) 2.1 2.4 2.2 <![CDATA[Porosity (cm 3 / g)]]> 0.206 0.221 0.238 Average pore size (nm) 9.813 9.478 9.326 <![CDATA[Specific surface area (m 2 / g)]]> 78.04 81.64 83.35

[0080] Product 1 was subjected to SEM testing, and the results were as follows Figure 2 As shown. Figure 2 It can be seen that the particle size of the SiO2 / C composite material is distributed in the range of 0.5 to 3 μm.

[0081] Products 1 to 3 were characterized by EDS spectra. The results are as follows Figure 3 As shown, Figure 3 a in is the characterization result of product 1, Figure 3 b in the figure is the characterization result of product 2. Figure 3 c in is the characterization result of product 3. Figure 3 It can be seen that by comparing the atomic percentages of carbon and silicon, it can be found that the proportion of carbon element gradually decreases, indicating that the solution of the present invention achieves the ratio control of carbon and silicon dioxide in the SiO2 / C composite material.

[0082] Application Example 1

[0083] 5, 10, 15, 20, 25 and 30 parts of product 1 were respectively mixed with a mixture of natural rubber, zinc oxide, stearic acid, silane coupling agent Si-69, antioxidant RD, accelerator DM and sulfur in the proportions shown in Table 2 to obtain functionalized rubber 1.

[0084] Application Example 2

[0085] 5, 10, 15, 20, 25 and 30 parts of product 2 were respectively mixed with a mixture of natural rubber, zinc oxide, stearic acid, silane coupling agent Si-69, antioxidant RD, accelerator DM and sulfur in the proportions shown in Table 2 to obtain functionalized rubber 2.

[0086] Application Example 3

[0087] 5, 10, 15, 20, 25 and 30 parts of product 3 were respectively mixed with a mixture of natural rubber, zinc oxide, stearic acid, silane coupling agent Si-69, antioxidant RD, accelerator DM and sulfur in the proportions shown in Table 2 to obtain functionalized rubber 3.

[0088] Comparative application example 1

[0089] 5, 10, 15, 20, 25 and 30 parts of carbon black N330 were respectively mixed with a mixture of natural rubber, zinc oxide, stearic acid, antioxidant RD, accelerator DM and sulfur in the proportions shown in Table 2 to obtain functionalized rubber 4.

[0090] Table 2. Proportions of Application Examples 1 to 3 and Comparative Application Example 1 (unit: parts)

[0091]

[0092]

[0093] Figure 4 This is a comparison curve of the low heat generation performance of products 1 to 3 and N330 carbon black in functionalized rubber. Figure 4 It can be seen that compared with carbon black, the low heat generation performance of functionalized rubber prepared by SiO2 / C composite material is significantly improved.

[0094] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a SiO2 / C composite material, characterized in that: The following steps are involved: (1) mixing the edible fungus cultivation body with porous silica to obtain a silica composite edible fungus cultivation body; The silicon dioxide composite edible fungus cultivation body is mixed with edible fungi to culture the edible fungi; after the culture is completed, the edible fungi are removed and the discarded cultivation body is retained; (2) Carbonizing the discarded culture medium in step (1) to obtain a SiO2 / C composite material.

2. The preparation method according to claim 1, characterized in that: The porous silica in step (1) includes one or more of silica powder, carbon monoxide, diatomaceous earth, diatom shale, opal, zeolite and montmorillonite.

3. The preparation method according to claim 1 or 2, characterized in that: The porous silica in step (1) has a particle size of 500 nm to 100 μm and a specific surface area of ​​60 to 500 m 2 / g, pore size is 2~100nm, porosity is 0.1~5cm 3 / g.

4. The preparation method according to claim 3, characterized in that: In step (1), the mass ratio of the porous silica to the edible fungus cultivation body is 1:1-10.

5. The preparation method according to claim 1, characterized in that: The time for completing the cultivation in step (1) is ≥ 3 months.

6. The preparation method according to claim 1 or 5, characterized in that: In step (2), the carbonization is carried out under a protective atmosphere, which is at least one of nitrogen or argon; the carbonization temperature is 600-950°C, the time is 10-60 min, and the rate of heating to the desired carbonization temperature is 5-15°C / min.

7. The preparation method according to claim 1, 2 or 5, characterized in that: After the carbonization in step (2), the process further includes: crushing and screening in sequence.

8. The preparation method according to claim 7, characterized in that: The crushing speed is 300-700 rpm, and the time is 15-60 min; the particle size D of the screening 50 =500nm~45μm.

9. A SiO2 / C composite material obtained by the preparation method according to any one of claims 1 to 8.

10. Use of the SiO2 / C composite material according to claim 9 in rubber, characterized in that: Based on the rubber dosage of 100phr, the dosage of the SiO2 / C composite material is 5-80phr; the rubber is natural rubber or synthetic rubber; the synthetic rubber is butadiene rubber or styrene-butadiene rubber.

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