CN115960394A

CN115960394A - Graphene-supported white carbon black composite material and preparation method and application thereof

Info

Publication number: CN115960394A
Application number: CN202111185452.8A
Authority: CN
Inventors: 刘海舟; 曹建苹
Original assignee: Beijing Graphene Institute BGI
Current assignee: Beijing Graphene Institute BGI
Priority date: 2021-10-12
Filing date: 2021-10-12
Publication date: 2023-04-14

Abstract

The invention provides a graphene supported white carbon black composite material and a preparation method and application thereof. The preparation method comprises the following steps: s1, preparing a sodium silicate solution; s2, preparing a graphene oxide dispersion liquid; s3, forming a mixed solution of graphene oxide and sodium silicate; s4, dropwise adding the mixed solution of graphene oxide and sodium silicate into the ammonium bicarbonate solution; s5, adding a reducing agent into the mixed solution obtained in the step S4; s6, filtering to obtain a solid mixture, and washing and drying the solid mixture; and S7, carrying out high-temperature treatment on the dried solid mixture. The white carbon black in the composite material prepared by the method is attached to the surface of the graphene, so that the low heat generation performance of the white carbon black can be exerted, and the secondary agglomeration of the graphene in the rubber can be prevented. The composite material is used as a rubber filler, has more excellent processing performance, obviously improves the fluidization mechanical property, and can improve the compression heat generation and mechanical property of rubber.

Description

Graphene-supported white carbon black composite material and preparation method and application thereof

Technical Field

The invention belongs to the technical field of graphene nano materials, and particularly relates to a graphene supported white carbon black composite material as well as a preparation method and application thereof.

Background

Graphene is a new material with a single-layer sheet structure composed of carbon atoms. It is a compound consisting of carbon atoms in sp ² The hybrid tracks form hexagonal honeycomb lattice planar films with only one carbon atom thick two-dimensional material. Since graphene has a plurality of excellent physicochemical properties, the graphene is widely applied to energy storage materials, environmental engineering and sensitive sensing, is called as 'black gold' or 'king of new materials', has a wide potential application prospect, has become a focus and a research hotspot in the world at present, and particularly has a great prospect for developing high-performance and multifunctional polymer nanocomposite materials due to the excellent performance of graphene. However, due to the sheet structure of graphene, it is easy to agglomerate in high molecular polymer such as rubber, and the agglomerated graphene may form stress concentration points, which affects the performance of the composite material.

Silica is commonly called white carbon black, is white, nontoxic and amorphous white powder, has the size of 10-40nm, has very large specific surface area and a large number of hydroxyl functional groups, can greatly reduce the compression heat generation of rubber, and is an important filler in rubber composite materials. But the strength of the prepared rubber composite material is poor due to the poor strength of the white carbon black.

The technical scheme that graphene and white carbon black are used as fillers of rubber is reported in existing researches and documents. The dispersibility of graphene in rubber is a key for preparing a high-performance rubber composite material, and if the filler dispersibility is poor, the high-performance rubber composite material is difficult to have good use value. Therefore, the dispersibility of the graphene and the white carbon black in the rubber matrix is solved, and the method becomes the key of the graphene and the white carbon black serving as good rubber fillers.

Therefore, how to obtain a mode can better enable the graphene and the white carbon black to be uniformly dispersed in the rubber matrix, and the enhancement of the graphene and the low heat generation performance of the white carbon black are fully exerted, which is the focus of attention of many research and development personnel and mechanisms at present.

Disclosure of Invention

The invention aims to provide a graphene supported white carbon black material, a preparation method thereof and application of the graphene supported white carbon black material as a rubber filler.

The invention provides a preparation method of a graphene supported white carbon black composite material, which comprises the following steps: s1, dissolving sodium silicate in water to prepare a sodium silicate solution; s2, dispersing graphene oxide in water to prepare a graphene oxide dispersion liquid; s3, adding the graphene oxide dispersion liquid into the sodium silicate solution, and then carrying out dispersion treatment to form a mixed solution of graphene oxide and sodium silicate; s4, dropwise adding the mixed solution of the graphene oxide and the sodium silicate into the ammonium bicarbonate solution, and continuously stirring in the dropwise adding process; s5, adding a reducing agent into the mixed solution obtained in the step S4; s6, filtering the mixed solution reacted in the step S5 to obtain a solid mixture, and washing and drying the solid mixture; and S7, performing high-temperature treatment on the dried solid mixture, wherein the temperature of the high-temperature treatment is 200-800 ℃, preferably 260 ℃, and the time of the high-temperature treatment is 1-6 hours, preferably 2 hours.

According to an embodiment of the present invention, the concentration of the sodium silicate solution in the S1 step is 1 to 10wt%, preferably 5wt%.

According to another embodiment of the present invention, the concentration of the graphene oxide dispersion in the S2 step is 0.1 to 2wt%, preferably 1wt%; preferably, the sheet diameter of the graphene oxide is 2-15 micrometers, and the thickness of the sheet layer of the graphene oxide is 0.7-10 nanometers; preferably, the oxygen content of the graphene oxide is 20 to 60wt%.

According to another embodiment of the present invention, in the S3 step, the mass ratio of the graphene oxide to the sodium silicate is 0.1 to 10:100.

according to another embodiment of the present invention, the concentration of the ammonium bicarbonate in the S4 step is 1 to 10wt%; the molar ratio of the ammonium bicarbonate to the sodium silicate is 2.0-3.0: 1.

according to another embodiment of the present invention, in the S5 step, the reducing agent is selected from one or more of vitamin C, hydrazine hydrate, sodium borohydride, hydrogen, ammonia, vitamin C, potassium hydroxide, sodium oxide, dimethylhydrazine, p-phenylenediamine, hydroiodic acid, and phenylhydrazine.

According to another embodiment of the present invention, the reducing agent is vitamin C, and the mass ratio of the vitamin C to the graphene oxide is 0.5 to 3:1; the temperature of the vitamin C for reducing the graphene oxide is 50-90 ℃, and preferably 80 ℃; the time for reducing the graphene oxide by the vitamin C is 0.5-4 h, preferably 1h.

According to another embodiment of the present invention, the pH of the solid-liquid mixture at the time of the filtration and the washing in the S6 step is 5 to 7.

The invention also provides the graphene-supported white carbon black composite material prepared by the method.

The invention also provides an application of the graphene supported white carbon black composite material as a rubber filler.

According to the composite material prepared by the method, the white carbon black is attached to the surface of the graphene, so that the low heat generation performance of the white carbon black can be exerted, and the flaky graphene can be separated to prevent the secondary agglomeration of the flaky graphene in rubber. Compared with rubber compound prepared by directly adding graphene and white carbon black into rubber, the composite material serving as rubber filler has the advantages that the processability is more excellent, the fluidization mechanical property is obviously improved, the compression heat generation and the mechanical property of the rubber can be improved, and the composite material is particularly suitable for tire rubber. In addition, the method of the invention basically does not change the production route of preparing the white carbon black by the existing precipitation method, has less equipment modification, does not increase the production cost, and has simple process and higher economic value.

Drawings

Fig. 1 is a schematic structural diagram of graphene supported white carbon black according to the present invention.

Fig. 2 is a scanning electron microscope image of the graphene supported white carbon black prepared in example 1.

Detailed Description

The technical solution of the present invention is further illustrated by the following specific examples. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitation of the present invention.

The preparation method of the graphene supported white carbon black composite material comprises the following steps: s1, dissolving sodium silicate in water to prepare a sodium silicate solution; s2, dispersing graphene oxide in water to prepare a graphene oxide dispersion liquid; s3, adding the graphene oxide dispersion liquid into a sodium silicate solution, and then performing dispersion treatment to form a mixed solution of graphene oxide and sodium silicate; s4, dropwise adding the mixed solution of graphene oxide and sodium silicate into the ammonium bicarbonate solution, and continuously stirring in the dropwise adding process; s5, adding a reducing agent into the mixed solution obtained in the step S4; s6, filtering the mixed solution reacted in the step S5 to obtain a solid mixture, and washing and drying the solid mixture; and S7, performing high-temperature treatment on the dried solid mixture, wherein the temperature of the high-temperature treatment is 200-800 ℃, preferably 260 ℃, and the time of the high-temperature treatment is 1-6 hours, preferably 2 hours.

In the step S1, the concentration of the sodium silicate solution is 1-10 wt%. The concentration of the sodium silicate solution is too low (less than 1 wt%), the efficiency of the subsequent reaction is low; at too high a concentration (above 10 wt%), the sodium silicate does not react completely in the subsequent reaction, resulting in unnecessary waste. Suitable concentration ranges can be selected as the case may be, such as, but not limited to, 1wt%, 3wt%, 5wt%, 7wt%, 9wt%, 10wt%, and the like. Preferably, the concentration of sodium silicate is 5wt%.

The concentration of the graphene oxide dispersion liquid in the step S2 is 0.1-2 wt%. The concentration of the graphene oxide in the dispersion liquid is lower than 0.1wt%, so that the subsequent reaction efficiency is low; the concentration is higher than 2wt%, the graphene oxide cannot be completely reacted in the subsequent reaction, and unnecessary waste is generated. The concentration of graphene oxide in the dispersion is preferably 1wt%. The sheet diameter of the graphene oxide in the dispersion liquid is 2-15 microns. The sheet diameter of the graphene oxide is larger than 15 microns, and the dispersion effect is poor; however, the sheet diameter of graphene oxide may be lower, and the sheet diameter of graphene oxide in the dispersion is selected to be 2 μm or more only in consideration of cost. The thickness of the graphene oxide lamella in the dispersion liquid is 0.7-10 nanometers. The thickness of the sheet layer is more than 10 nanometers, so that the number of layers of the graphene oxide is more, and the graphene oxide cannot play a role in enhancing. Graphene oxide below 0.7 nm still achieves the objects of the invention but at a too high cost. The thickness of the graphene oxide sheet is preferably 0.7 nm or more in consideration of cost, and any value within the above range may be selected by those skilled in the art according to actual needs, such as but not limited to 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, etc. Specific sheet layers of graphene may also be selected, such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, etc. The oxygen content of the graphene oxide in the dispersion liquid is 20-60 wt%. When the oxygen content in the graphene oxide is less than 20wt%, the dispersion performance of the graphene oxide in the dispersion liquid is poor; if the oxygen content of graphene oxide is too high, the cost is high, and the oxidation cannot be technically achieved, so that the oxidation amount of graphene oxide is preferably 20wt% to 60wt%. Any value within the above range can be selected by one skilled in the art according to the actual need, such as but not limited to 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, etc.

In the step S3, the mass ratio of the graphene oxide to the sodium silicate is 0.1-10: 100. the mass ratio of the graphene oxide to the sodium silicate is lower than 0.1: at 100, the content of graphene in the composite material is too low, and the enhancement effect of the graphene is not obvious; if the mass ratio of the graphene oxide to the sodium silicate is higher than 1:100, the graphene may not be sufficiently dispersed during the formation of the composite material, and the performance of the composite material may be deteriorated. Any value within the above range can be selected by one skilled in the art according to practical needs, such as, but not limited to, 0.1: 100. 0.2: 100. 0.3: 100. 0.4: 100. 0.5: 100. 0.6: 100. 0.7: 100. 0.8: 100. 0.9: 100. 1: 100. 1.5: 100. 2: 100. 2.5: 100. 3: 100. 3.5: 100. 4: 100. 4.5: 100. 5: 100. 5.5: 100. 6: 100. 6.5: 100. 7: 100. 7.5: 100. 8: 100. 8.5: 100. 9: 100. 9.5: 100. 10:100, etc.

The concentration of ammonium bicarbonate in step S4 is 1-10 wt%. When the concentration of ammonium bicarbonate is less than 1wt%, the subsequent reaction is incomplete; when the concentration of ammonium bicarbonate in the solution is higher than 10wt%, the graphene oxide in the solution is agglomerated. Thus, the concentration of ammonium bicarbonate can be selected from any value within the above range, such as, but not limited to, 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, and the like. The mass of the ammonium bicarbonate solution is calculated according to the molar mass of sodium silicate contained in the sodium silicate solution, and the molar ratio of the ammonium bicarbonate to the sodium silicate is (2.0-3.0): 1. the molar ratio of ammonium bicarbonate to sodium silicate is lower than 2.0:1, the reaction is incomplete; the molar ratio of ammonium bicarbonate to sodium silicate is higher than 3.0: at 1, the ammonium hydrogen silicate is in excess and is wasted.

The graphene oxide is primarily reduced in the S5 step. The reducing agent is selected from one or more of vitamin C, hydrazine hydrate, sodium borohydride, hydrogen, ammonia gas, vitamin C, potassium hydroxide, sodium oxide, dimethylhydrazine, p-phenylenediamine, hydroiodic acid and phenylhydrazine. When the reducing agent is vitamin C, the mass ratio of the vitamin C to the graphene oxide is 0.5-3: 1. the temperature of the vitamin C for reducing the graphene oxide is 50-90 ℃, and preferably 80 ℃. The time for reducing the graphene oxide by the vitamin C is 0.5-4 h, and preferably 1h. The above reaction conditions are preferred parameters for the reaction of vitamin C with graphene oxide. When other reducing agents are selected, those skilled in the art can select an appropriate mass ratio, reaction temperature, time, and the like according to the kind of the reducing agent.

The pH of the solid-liquid mixture at the time of filtration and washing in the step S6 is 5 to 7. The filtration may be suction filtration. The suction filtration process may be that the mixed solution after the reaction in step S5 is treated to obtain a solid mixture, and the filter cake is added again to excess water, and diluted hydrochloric acid is added dropwise while stirring to adjust the pH value to 5 to 7. The excessive water accounts for 5 to 20 times of the mass of the filter cake. The molar mass of the dilute hydrochloric acid is 0.1-2 mol/L. The dilute hydrochloric acid may be one or more of dilute sulfuric acid, dilute nitric acid, and acetic acid. The purpose of the above steps is to wash the solid mixture, which is dried after washing. The drying treatment may be one or more of forced air drying, vacuum drying, and freeze drying. When forced air drying is used, the drying temperature is 60 to 120 ℃, preferably 80 ℃. The drying time is 2h to 10h, preferably 6h. The spray drying may be carried out, and in the case of the spray drying, the pH of the solution containing the solid mixture may be adjusted to 5 to 7, and then the mixed solution may be directly spray-dried. The drying temperature for spray drying is 100 to 200 ℃, preferably 150 ℃.

In step S7, the dried solid mixture is subjected to a high temperature treatment. The graphene oxide is further reduced during the high-temperature treatment. The temperature of the high-temperature treatment is 200-800 ℃. The graphene can be decomposed at the high-temperature treatment temperature of more than 800 ℃, and the white carbon black can not be completely dehydrated at the high-temperature treatment temperature of less than 200 ℃. Preferably 260 deg.c. The time of high-temperature treatment is 1-6 h, the graphene is easily decomposed if the treatment time is too long, and the moisture in the white carbon black cannot be completely removed if the treatment time is too short.

The invention also discloses the graphene supported white carbon black composite material prepared by the method. A microscopic schematic diagram of the graphene-supported white carbon black composite material prepared by the method of the invention is shown in fig. 1, that is, white carbon black particles 2 are supported on the surface of a graphene sheet layer 1. Therefore, the low heat generation performance of the white carbon black can be exerted, and the flaky graphene can be separated to prevent the secondary agglomeration of the flaky graphene in the rubber. The graphene-supported white carbon black composite material prepared by the method can be used as a rubber filler. Compared with a rubber compound prepared by directly adding graphene and white carbon black into rubber, the composite material serving as a rubber filler has more excellent processing performance and obviously improved fluidization mechanical property, can improve the compression heat generation and mechanical property of the rubber, and is particularly suitable for tire rubber. In addition, the method does not basically change the production route for preparing the white carbon black by the existing precipitation method, has small equipment modification, does not increase the production cost, and has simple process and higher economic value.

Example 1

(1) Adding water into a reaction kettle, heating by using an oil bath to control the temperature of the water to be 80 ℃, adding powdery instant sodium silicate to prepare a sodium silicate solution with the concentration of 5wt%, wherein the temperature is kept at 80 ℃ in the whole process of preparing the sodium silicate solution.

(2) And (3) adding graphene oxide accounting for 2% of the mass of the sodium silicate into deionized water, and stirring at a high speed for 2 hours. Wherein the graphene oxide comprises 10 layers, the sheet diameter is 2 microns, and the oxygen content is 30wt%.

(3) Dispersing the treated graphene oxide into a sodium silicate solution, and homogenizing the mixed solution by using a high-pressure homogenizer at the homogenizing pressure of 800bar for 1h.

(4) Adding ammonium bicarbonate into water, heating to 30 ℃, and preparing into 2.4mol/L ammonium bicarbonate solution.

(5) And (3) dropwise adding the prepared mixed solution of the graphene oxide and the sodium silicate into the ammonium bicarbonate solution by using a peristaltic pump, and continuously stirring.

(6) Adding 1wt% of vitamin C aqueous solution into the reactant of the step (5), heating to 80 ℃ in an oil bath, and reacting for 1h.

(7) And (4) carrying out suction filtration on the product obtained in the step (6), adding a filter cake into excessive water, stirring until the excessive water is completely dispersed, and adjusting the pH value to 7 by using 1mol/L dilute hydrochloric acid.

(8) And (4) carrying out suction filtration on the mixture with the adjusted pH value, and drying the filter cake for 6h at 80 ℃ by using an air-blast drying oven.

(9) And (3) treating the dried solid at 260 ℃ for 2h to obtain the graphene supported white carbon black material.

Example 2

The procedure was the same as in example 1 except that the mass of graphene oxide of step (2) was 4wt% of the mass of sodium silicate.

Example 3

(1) Adding water into a reaction kettle, heating by using an oil bath to control the temperature of the water to be 80 ℃, adding powdery instant sodium silicate, and preparing the sodium silicate solution with the concentration of 5wt%, wherein the temperature is kept at 80 ℃ in the whole process of preparing the sodium silicate solution.

(2) And adding graphene oxide accounting for 2wt% of the sodium silicate by mass into deionized water, and stirring at a high speed for 2 hours. Wherein the graphene oxide comprises 10 layers, the sheet diameter is 2 microns, and the oxygen content is 30wt%.

(3) Dispersing the treated graphene oxide into a sodium silicate solution, and treating the mixed solution by high-speed stirring for 2 hours at a rotating speed of 3000r/min.

(6) Adding 1wt% of vitamin C aqueous solution into the reactant in the step (5), heating the mixture to 60 ℃ in an oil bath, reacting for 3 hours, and then adjusting the pH value to 7 by using dilute hydrochloric acid.

(7) The mixture with the adjusted pH value is sprayed and dried at the drying temperature of 120 ℃.

(8) And (3) treating the dried solid at the high temperature of 400 ℃ for 2 hours to obtain the graphene supported white carbon black material.

Example 4

The procedure was the same as in example 3 except that the mass of graphene oxide of step (2) was 4wt% of the mass of sodium silicate.

Comparative example 1

This comparative example refers to example 1, except that steps (2) and (3) are absent.

Comparative example 2

This comparative example refers to example 1 with the difference that: and (3) directly mixing graphene oxide accounting for 2wt% of the mass of the sodium silicate with the solid obtained in the step (7) without the steps (2) and (3), and then performing the step (8).

Comparative example 3

This comparative example refers to example 3, except that steps (2) and (3) are absent.

Comparative example 4

This comparative example refers to example 3 with the difference that: and (3) directly mixing graphene oxide accounting for 2wt% of the mass of the sodium silicate with the solid obtained in the step (7) without the steps (2) and (3), and then performing the step (8).

The composite material prepared in example 1 was subjected to electron microscope scanning, and the photograph is shown in FIG. 2. As can be seen from fig. 2, the white carbon black is loaded on the surface of the graphene sheet layer. Therefore, the method provided by the invention can be used for loading the white carbon black on the surface of the graphene sheet layer, so that the low heat generation performance of the white carbon black is fully realized, and the aggregation of graphene can be prevented.

Rubber mixes were prepared using the composites prepared in each of examples 1 to 4 and comparative examples 1 to 4, and the prepared rubber mixes were tested.

The preparation method comprises the following steps:

the formula is as follows: smoked sheet rubber (No. 3), 70g; 30g of butadiene rubber (BR 9000) and 100g of graphene-loaded white carbon black; silicon 69,1g; 5g of zinc oxide; stearic acid, 2g; anti-aging agent (RD), 3.5g; anti-aging agent (4020), 2g; microcrystalline wax, 1g; accelerator (D), 2.1g; 2g of accelerant (CZ); sulfur, 4g.

The formula is prepared by the following preparation method:

(1) Adjusting the roller distance to be 1mm, adding smoked sheet rubber and butadiene rubber, wrapping the rubber on the roller, breaking the rubber without wrapping the roller, and wrapping the rubber on the roller.

(2) Evenly and slowly adding sulfur, and after the sulfur is mixed, alternately cutting 6 knives (alternately cutting the knives into one knife) by 3/4 knives from the two ends of the roller every 20 s. The operation time is 4min.

(3) Uniformly adding zinc oxide, and alternately cutting for 2/4 times from two ends of the roller every 20 s. The operation time is 1.5min.

(4) Stearic acid is added evenly, and 3/4 cutting knives and 2 cutting knives are alternately used every 20s from the two ends of the roller. The operation time is 1.5min.

(5) Adding 1/3 white carbon black, alternately cutting for 3/4 times from two ends of the roller every 20s, and cutting for 4 times. The operation time is 5min.

(6) 1/3 white carbon black is added, and 3/4 cutters are alternately used for cutting 4 cutters from two ends of the roller every 20 s. The operation time is 5min.

(7) Adding 1/3 of white carbon black, adding an active agent PEG4000, alternately cutting 3/4 of the roller from two ends every 20s, and cutting 6 of the roller. The operation time is 8.5min.

(8) The accelerator was slowly added evenly over the rubber. When all the materials are mixed, 3/4 cutting knives are alternately used for cutting 4 knives from the two ends of the roller every 20s, and the operation time is 3.5min.

(9) The rubber sheet is cut off from the rubber mixing mill and wrapped for 3 times by triangular wraps. The operation time is 1.5min.

(10) Cutting off the rubber sheet from the rubber mixing mill, adjusting the roller spacing to 2mm, and passing the rubber material through the roller for 3 times for 1min without wrapping the roller.

(11) The rubber material is cut off from the rubber sheet, and the total operation time is 31.5min.

(12) Taking down the film and marking according to the film outlet direction.

The sizing material can be subjected to related processing performance and mechanical performance test after being placed for 24 hours at normal temperature. The test results are shown in table 1:

table 1 change of processability and mechanical properties of graphene-supported white carbon black rubber with reaction conditions

The vulcanization time T90 represents: the time required for the compound to rise from the start of heating to 90% of the maximum torque, m: s representing the unit of time in minutes and seconds.

It can be seen from the results of the above examples and comparative examples that the white carbon black obtained by the method of the present invention has excellent processability in tire rubber, and the mechanical properties of vulcanized rubber are also significantly improved. The method provided by the invention has the advantages of simple process, no need of adding a silane coupling agent or other additives, no increase of production cost and good technical economy. The comparative example did not adopt the scheme of the present invention, and thus the excellent effects of the present invention could not be obtained.

The applicant states that the present invention is illustrated in detail by the above examples, but the present invention is not limited to the above detailed methods, i.e. it is not meant that the present invention must rely on the above detailed methods for its implementation. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention. The invention is further described below by means of specific examples. However, these examples are merely illustrative and do not limit the scope of the present invention in any way.

Claims

1. The preparation method of the graphene supported white carbon black composite material is characterized by comprising the following steps:

s1, dissolving sodium silicate in water to prepare a sodium silicate solution;

s2, dispersing graphene oxide in water to prepare a graphene oxide dispersion liquid;

s3, adding the graphene oxide dispersion liquid into the sodium silicate solution, and then performing dispersion treatment to form a mixed solution of graphene oxide and sodium silicate;

s4, dropwise adding the mixed solution of the graphene oxide and the sodium silicate into the ammonium bicarbonate solution, and continuously stirring in the dropwise adding process;

s5, adding a reducing agent into the mixed solution obtained in the step S4;

s6, filtering the mixed solution reacted in the step S5 to obtain a solid mixture, and washing and drying the solid mixture; and

and S7, carrying out high-temperature treatment on the dried solid mixture, wherein the temperature of the high-temperature treatment is 200-800 ℃, preferably 260 ℃, and the time of the high-temperature treatment is 1-6 hours, preferably 2 hours.

2. The method according to claim 1, wherein the concentration of the sodium silicate solution in the step S1 is 1 to 10wt%, preferably 5wt%.

3. The method according to claim 1, wherein the concentration of the graphene oxide dispersion in the S2 step is 0.1 to 2wt%, preferably 1wt%; preferably, the sheet diameter of the graphene oxide is 2-15 micrometers, and the thickness of the sheet layer of the graphene oxide is 0.7-10 nanometers; preferably, the oxygen content of the graphene oxide is 20 to 60wt%.

4. The preparation method according to claim 1, wherein in the step S3, the mass ratio of the graphene oxide to the sodium silicate is 0.1 to 10:100.

5. the method according to claim 1, wherein the concentration of the ammonium bicarbonate in the step S4 is 1 to 10wt%; the molar ratio of the ammonium bicarbonate to the sodium silicate is 2.0-3.0: 1.

6. the preparation method according to claim 1, wherein the reducing agent in the step S5 is one or more selected from the group consisting of vitamin C, hydrazine hydrate, sodium borohydride, hydrogen, ammonia, vitamin C, potassium hydroxide, sodium oxide, dimethylhydrazine, terepensin, hydroiodic acid, and phenylhydrazine.

7. The preparation method according to claim 6, wherein the reducing agent is vitamin C, and the mass ratio of the vitamin C to the graphene oxide is 0.5-3: 1; the temperature of the vitamin C for reducing the graphene oxide is 50-90 ℃, and the optimal temperature is 80 ℃; the time for reducing the graphene oxide by the vitamin C is 0.5-4 h, preferably 1h.

8. The production method according to claim 1, wherein a pH value of the solid-liquid mixture at the time of the filtration and the washing in the S6 step is 5 to 7.

9. The graphene-supported white carbon black composite material is characterized by being prepared by the method of any one of claims 1 to 8.

10. The application of the graphene supported white carbon black composite material of claim 9 as a rubber filler.