阅读说明：本技术 一种石墨烯/二氧化硅/天然橡胶复合材料及其制备方法、应用 (Graphene/silicon dioxide/natural rubber composite material and preparation method and application thereof ) 是由 盖东杰 赵永彬 赵新新 马立军 于 2018-06-07 设计创作，主要内容包括：本发明提供了一种石墨烯/二氧化硅/天然橡胶复合材料,包括石墨烯、二氧化硅和天然橡胶；所述二氧化硅颗粒附着在所述石墨烯片层上,所述石墨烯片层插嵌在所述天然橡胶的网络中。本发明将石墨烯原料、二氧化硅原料与天然橡胶先进行复合,得到石墨烯/二氧化硅/天然橡胶复合材料,该材料中二氧化硅颗粒附着在石墨烯片层上,而石墨烯片层插嵌在天然橡胶的网络中,从而达到了石墨烯和二氧化硅在天然橡胶中的均匀分散,进而再用于橡胶复合材料中,能够提高轮胎的导静电能力,降低滚阻,提高轮胎的撕裂性能。而且本发明提供的制备方法简单实用,更具实用性,适合工业化大生产应用。(the invention provides a graphene/silicon dioxide/natural rubber composite material, which comprises graphene, silicon dioxide and natural rubber; the silica particles are attached to the graphene sheets, which are embedded in the network of natural rubber. According to the invention, the graphene raw material, the silicon dioxide raw material and the natural rubber are firstly compounded to obtain the graphene/silicon dioxide/natural rubber composite material, silicon dioxide particles in the material are attached to graphene sheet layers, and the graphene sheet layers are inserted into a network of the natural rubber, so that the graphene and the silicon dioxide are uniformly dispersed in the natural rubber, and then the graphene/silicon dioxide/natural rubber composite material is used in the rubber composite material, so that the static electricity conducting capability of a tire can be improved, the rolling resistance is reduced, and the tearing performance of the tire is improved. The preparation method provided by the invention is simple and practical, has higher practicability and is suitable for industrial mass production and application.)

1. A graphene/silica/natural rubber composite material is characterized by comprising graphene, silica and natural rubber;

the silica particles are attached to the graphene sheets, which are embedded in the network of natural rubber.

2. the composite material according to claim 1, wherein the graphene/silica/natural rubber composite material is prepared from graphene oxide, silica sol and natural rubber;

The thickness of the graphene sheet layer is 0.7-2 nm;

The particle size of the silicon dioxide is 10-40 nm.

3. the graphene/white carbon black composite material as claimed in claim 1, wherein the molecular weight of the natural rubber is 5000-30000;

the cis-1, 4-polyisoprene content in the natural rubber is more than or equal to 50 percent;

the mass ratio of the graphene to the silicon dioxide is 1: (1-10);

The mass ratio of the graphene to the natural rubber is 1: (1-30).

4. The preparation method of the graphene/silicon dioxide/natural rubber composite material is characterized by comprising the following steps:

1) Carrying out ultrasonic dispersion on a graphene oxide aqueous solution and silica sol to obtain a dispersion liquid;

2) ultrasonically dispersing the dispersion liquid obtained in the step and the natural rubber again to obtain mixed slurry;

3) Reacting the mixed slurry obtained in the step with a reducing agent to obtain graphene/silica sol/natural rubber composite liquid;

4) And demulsifying the graphene/silica sol/natural rubber composite liquid obtained in the step to obtain the graphene/silica/natural rubber composite material.

5. The preparation method according to claim 4, wherein the step 1) is specifically:

Ultrasonically stirring a graphene oxide aqueous solution, and then dropwise adding silica sol into the graphene oxide aqueous solution to obtain a dispersion liquid;

the dropping speed is 5-50 mL/min;

the mass concentration of the graphene oxide aqueous solution is 0.1-10%.

6. the preparation method according to claim 4, wherein the ultrasonic dispersion time is 1-10 h;

the ultrasonic frequency of the ultrasonic dispersion is 500-5000 Hz;

The stirring speed of the ultrasonic dispersion is 50-1000 r/min;

the mass ratio of the graphene oxide to the silica sol is 1: (2-50);

The solid content of the silica sol is 1-50%;

The silica sol may be an acidic silica sol or an alkaline silica sol.

7. The preparation method according to claim 4, wherein the step 2) is specifically:

dropwise adding the dispersion liquid obtained in the step into natural rubber under the condition of ultrasonic stirring again to obtain mixed slurry;

The dropping speed is 5-50 mL/min;

The ultrasonic stirring time is 1-10 h;

The ultrasonic frequency of the ultrasonic stirring is 500-5000 Hz;

the stirring speed of the ultrasonic stirring is 50-1000 r/min.

8. The method of claim 4, wherein the reducing agent comprises one or more of hydrazine hydrate, vitamin c, sodium borohydride, potassium hydroxide, and ammonia gas;

the mass ratio of the graphene oxide to the reducing agent is 1: (1-10);

the reaction time is 1-48 h; the reaction temperature is 0-150 ℃.

9. The preparation method of claim 4, wherein the demulsifier for demulsification comprises one or more of dilute sulfuric acid, white acetic acid, calcium chloride, formic acid and ethanol;

The mass ratio of the graphene oxide to the demulsifier is 1: (1-100);

the demulsification time is 1-100 min; the demulsification temperature is 10-50 ℃;

And the demulsification also comprises a post-treatment step.

10. The graphene/silica/natural rubber composite material according to any one of claims 1 to 3 or the graphene/silica/natural rubber composite material prepared by the preparation method according to any one of claims 4 to 9 is applied to rubber composite materials.

Technical Field

The invention belongs to the technical field of rubber materials, relates to a graphene/silicon dioxide/natural rubber composite material, and a preparation method and application thereof, and particularly relates to a graphene/silicon dioxide/natural rubber composite material, a preparation method thereof, and application thereof in a rubber composite material matrix.

Background

graphene (Graphene) is a new material with a monolayer sheet structure composed of carbon atoms. The material is a hexagonal honeycomb-shaped planar film consisting of carbon atoms in sp2 hybridized orbitals, and is a two-dimensional material with the thickness of only one carbon atom. 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. Among many polymer materials, rubber materials are a very important class, and thus, graphene has particular importance in rubber reinforcement research.

In recent years, rubber products containing graphene-based materials have been reported, but in practical applications, the graphene-based materials have many problems and restriction factors, such as easy agglomeration of graphene. Because the specific surface area of the graphene material is large, the sheets are easy to superpose and agglomerate due to the action of Van der Waals force and the interaction of pi-pi electrons, so that the graphene material cannot be stably dispersed and is more difficult to uniformly disperse in a rubber matrix.

one of the most widely used fillers in the tire industry at present is white carbon black, which is mainly used as a reinforcing agent in the rubber industry, and the reinforcing effect of the white carbon black is second to that of carbon black and superior to that of other white fillers. The white carbon black is superior to carbon black in improving tear strength and reducing rolling resistance. 95-99% of white carbon black is SiO₂the surface of the white carbon black has hydroxyl and siloxane groups. The surface characteristics of the white carbon black make the white carbon black tend to agglomerate twice, and the white carbon black is easy to absorb moisture and generate hydrogen bond association. The secondary agglomeration is far more difficult to mix and disperse than the carbon black; in addition, when the amount is large, gel is generated in a large amount to harden the rubber. And the dispersibility of the filler in the rubber is controlledThe key point of preparing the high-performance rubber composite material. If the dispersibility of the filler is poor, it is difficult to obtain a good use value.

therefore, how to solve the dispersion of graphene in the rubber matrix and solve the contradiction between the graphene and the white carbon black which is one of the main fillers becomes the key for preparing the graphene/rubber composite material. Although various methods such as solution synthesis or in-situ polymerization are disclosed in the prior art, the dispersibility of the white carbon black in water is poor, and the dispersibility of the graphene in water is good, so that when the composite materials such as the graphene and the white carbon black are synthesized by adopting a solution polymerization method, the white carbon black is poor in dispersibility in water and is easy to precipitate.

Therefore, how to find a suitable graphene rubber composite material, solve the problem of dispersibility between graphene and the filler thereof, and improve the performance of the rubber material has become one of the focuses of common attention of many graphene manufacturers and application manufacturers in the industry.

Disclosure of Invention

In view of the above, the technical problem to be solved by the present invention is to provide a graphene/silica/natural rubber composite material, a preparation method thereof, and an application thereof in a rubber composite material matrix. And the preparation method is simple and practical and has higher practicability.

the invention provides a graphene/silicon dioxide/natural rubber composite material, which comprises graphene, silicon dioxide and natural rubber;

The silica particles are attached to the graphene sheets, which are embedded in the network of natural rubber.

preferably, the graphene/silicon dioxide/natural rubber composite material is prepared from graphene oxide, silica sol and natural rubber;

The thickness of the graphene sheet layer is 0.7-2 nm;

the particle size of the silicon dioxide is 10-40 nm.

Preferably, the molecular weight of the natural rubber is 5000-30000;

The cis-1, 4-polyisoprene content in the natural rubber is more than or equal to 50 percent;

the mass ratio of the graphene to the silicon dioxide is 1: (1-10);

The mass ratio of the graphene to the natural rubber is 1: (1-30).

The invention also provides a preparation method of the graphene/silicon dioxide/natural rubber composite material, which comprises the following steps:

1) carrying out ultrasonic dispersion on a graphene oxide aqueous solution and silica sol to obtain a dispersion liquid;

2) ultrasonically dispersing the dispersion liquid obtained in the step and the natural rubber again to obtain mixed slurry;

3) reacting the mixed slurry obtained in the step with a reducing agent to obtain graphene/silica sol/natural rubber composite liquid;

4) And demulsifying the graphene/silica sol/natural rubber composite liquid obtained in the step to obtain the graphene/silica/natural rubber composite material.

Preferably, the step 1) is specifically:

Ultrasonically stirring a graphene oxide aqueous solution, and then dropwise adding silica sol into the graphene oxide aqueous solution to obtain a dispersion liquid;

The dropping speed is 5-50 mL/min;

The mass concentration of the graphene oxide aqueous solution is 0.1-10%.

Preferably, the ultrasonic dispersion time is 1-10 h;

the ultrasonic frequency of the ultrasonic dispersion is 500-5000 Hz;

The stirring speed of the ultrasonic dispersion is 50-1000 r/min;

The mass ratio of the graphene oxide to the silica sol is 1: (2-50);

The solid content of the silica sol is 1-50%;

The silica sol may be an acidic silica sol or an alkaline silica sol.

Preferably, the step 2) is specifically:

Dropwise adding the dispersion liquid obtained in the step into natural rubber under the condition of ultrasonic stirring again to obtain mixed slurry;

the dropping speed is 5-50 mL/min;

the ultrasonic stirring time is 1-10 h;

The ultrasonic frequency of the ultrasonic stirring is 500-5000 Hz;

The stirring speed of the ultrasonic stirring is 50-1000 r/min.

Preferably, the reducing agent comprises one or more of hydrazine hydrate, vitamin c, sodium borohydride, potassium hydroxide and ammonia gas;

the mass ratio of the graphene oxide to the reducing agent is 1: (1-10);

The reaction time is 1-48 h; the reaction temperature is 0-150 ℃.

preferably, the demulsifier for demulsification comprises one or more of dilute sulfuric acid, white acetic acid, calcium chloride, formic acid and ethanol;

The mass ratio of the graphene oxide to the demulsifier is 1: (1-100);

the demulsification time is 1-100 min; the demulsification temperature is 10-50 ℃;

and the demulsification also comprises a post-treatment step.

the invention also provides an application of the graphene/silicon dioxide/natural rubber composite material prepared by the preparation method in any one of the technical schemes or the application of the graphene/silicon dioxide/natural rubber composite material prepared by the preparation method in any one of the technical schemes in the aspect of rubber composite materials.

The invention provides a graphene/silicon dioxide/natural rubber composite material, which comprises graphene, silicon dioxide and natural rubber; the silica particles are attached to the graphene sheets, which are embedded in the network of natural rubber. Compared with the prior art, the invention aims at the defects that the existing graphene modified rubber product is easy to superpose and agglomerate, cannot be stably dispersed, is more difficult to uniformly disperse in a rubber matrix, and is difficult to disperse white carbon black in the rubber matrix, so that the graphene is difficult to exert better performance due to interaction of the graphene and the rubber when the graphene is used for modified rubber.

according to the invention, the graphene raw material, the silicon dioxide raw material and the natural rubber are creatively compounded to obtain the graphene/silicon dioxide/natural rubber composite material, silicon dioxide particles in the material are attached to the graphene sheet layers, and the graphene sheet layers are inserted into the network of the natural rubber, so that the graphene and the silicon dioxide are uniformly dispersed in the natural rubber, and then the graphene/silicon dioxide composite material is used in the rubber composite material, so that the static electricity conducting capacity of the tire can be improved, the rolling resistance is reduced, and the tearing performance of the tire is improved. The preparation method provided by the invention is simple and practical, has higher practicability and is suitable for industrial mass production and application.

experimental results show that when the graphene/silicon dioxide/natural rubber composite material is used in tires, the static electricity conducting capacity of the tires is improved, the static electricity conducting requirement is met, the abrasion is reduced by more than 5%, and the 300% stress at definite elongation is improved by 3%. The rolling resistance is reduced.

drawings

Fig. 1 is an SEM scanning electron micrograph of the graphene/silica/natural rubber composite material prepared in example 1 of the present invention;

Fig. 2 is an SEM scanning electron micrograph of the graphene/silica/natural rubber composite material prepared in example 2 of the present invention;

Fig. 3 is an SEM scanning electron micrograph of the graphene/silica/natural rubber composite material prepared in example 3 of the present invention.

Detailed Description

For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims.

All of the starting materials of the present invention, without particular limitation as to their source, may be purchased commercially or prepared according to conventional methods well known to those skilled in the art.

All the raw materials of the present invention are not particularly limited in their purity, and the present invention preferably adopts the conventional purity used in the analytical purification, graphene field or rubber field.

The raw materials used in the invention, the abbreviation or the brand thereof belong to the conventional abbreviation or brand in the field, each abbreviation or brand is clear and definite in the field of related application, and the skilled person in the art can clearly, accurately and uniquely understand and obtain the abbreviation or brand.

The invention provides a graphene/silicon dioxide/natural rubber composite material, which comprises graphene, silicon dioxide and natural rubber; the silica particles are attached to the graphene sheets, which are embedded in the network of natural rubber.

the parameters and the form of the graphene/silica/natural rubber composite material are not particularly limited, and those skilled in the art can select and adjust the parameters and the form according to the actual production situation, the product quality and the use requirement. The graphene/silicon dioxide/natural rubber composite material is more particularly and preferably prepared from graphene oxide, silica sol and natural rubber.

The parameters of the silica particles attached to the graphene sheets are not particularly limited, and may be selected and adjusted by those skilled in the art according to the actual production conditions, the product quality and the use requirements. The particle size of the silicon dioxide is preferably 10-40 nm, more preferably 15-35 nm, and more preferably 20-30 nm.

the proportion of the silica particles is not particularly limited in the present invention, and can be selected and adjusted by those skilled in the art according to actual production conditions, product quality and use requirements, and the mass ratio of the graphene to the silica in the present invention is preferably 1: (1-10), more preferably 1: (3-8), more preferably 1: (5-6).

The parameters of the graphene are not particularly limited in the present invention, and may be conventional parameters of graphene well known to those skilled in the art, and those skilled in the art can select and adjust the parameters according to actual production conditions, product quality and use requirements, and the graphene sheets of the present invention are embedded in the network of the natural rubber. The thickness of the sheet layer of the graphene is preferably 0.7-2 nm, more preferably 1.0-1.7 nm, and more preferably 1.2-1.5 nm.

The addition amount of the graphene is not particularly limited, and can be selected and adjusted by a person skilled in the art according to actual production conditions, product quality and use requirements, and the mass ratio of the graphene to the natural rubber is preferably 1: (1 to 30), more preferably 1: (5-25), more preferably 1: (10-20).

The parameters of the natural rubber are not particularly limited, and the conventional parameters of the natural rubber known by the skilled in the art can be used, and the skilled in the art can select and adjust the parameters according to the actual production condition, the product quality and the use requirement, and the molecular weight of the natural rubber is preferably 5000-30000, more preferably 10000-25000, and more preferably 15000-20000. The natural rubber of the present invention preferably contains 50% or more, more preferably 70% or more, still more preferably 90% or more, and still more preferably 95% or more of cis-1, 4-polyisoprene.

The invention also provides a preparation method of the graphene/silicon dioxide/natural rubber composite material, which comprises the following steps:

1) Carrying out ultrasonic dispersion on a graphene oxide aqueous solution and silica sol to obtain a dispersion liquid;

2) ultrasonically dispersing the dispersion liquid obtained in the step and the natural rubber again to obtain mixed slurry;

3) Reacting the mixed slurry obtained in the step with a reducing agent to obtain graphene/silica sol/natural rubber composite liquid;

4) And demulsifying the graphene/silica sol/natural rubber composite liquid obtained in the step to obtain the graphene/silica/natural rubber composite material.

The selection, composition and structure of the materials in the preparation method and the corresponding preferred principle of the invention can preferably correspond to the selection, composition and structure of the graphene/silica/natural rubber composite material and the corresponding preferred principle, and are not described in detail herein.

firstly, carrying out ultrasonic dispersion on a graphene oxide aqueous solution and silica sol to obtain a dispersion liquid.

The parameters of the graphene oxide are not particularly limited in the present invention, and may be selected and adjusted by those skilled in the art according to actual production conditions, compounding conditions, and product properties, and the graphene oxide of the present invention preferably has a proportion of graphene oxide with a lamellar structure of 5 or less, preferably 80% or more, more preferably 85% or more, and more preferably 90% or more. The thickness of the graphene oxide sheet layer is preferably 0.7-2 nm, more preferably 1.0-1.8 nm, and more preferably 1.2-1.5 nm. The sheet diameter of the graphene oxide sheet layer is preferably 7-20 μm, more preferably 10-18 μm, and more preferably 12-15 μm. The specific surface area of the graphene material is preferably 400-600 m²(ii)/g, more preferably 420 to 580m²(iv)/g, more preferably 450 to 550m²(ii) in terms of/g. The oxygen content of the graphene oxide is preferably 10% to 70%, more preferably 20% to 60%, and more preferably 30% to 50%.

The concentration of the graphene oxide aqueous solution is not particularly limited, and may be the concentration of a conventional graphene oxide aqueous solution known to those skilled in the art, and those skilled in the art may select and adjust the concentration according to actual production conditions, product quality and use requirements, and in order to further improve the dispersion performance and stability of the composite material and ensure the specific structure of the composite material, the mass concentration of the graphene oxide aqueous solution is preferably 0.1% to 10%, more preferably 0.5% to 8%, more preferably 1% to 5%, and more preferably 2% to 4%.

The definition and parameters of the silica sol are not particularly limited in the present invention, and the silica sol may be defined and parameters of silica sol known to those skilled in the art, and may be commercially available or prepared according to conventional methods, and those skilled in the art may select and adjust the silica sol according to actual production conditions, compounding conditions and product properties. The solid content of the silica sol of the present invention is preferably 1% to 50%, more preferably 5% to 45%, more preferably 10% to 40%, and more preferably 20% to 30%.

the adding proportion of the graphene oxide and the silica sol is not particularly limited, and a person skilled in the art can select and adjust the adding proportion according to the actual production condition, the composite condition and the product performance, in order to further ensure the uniform dispersion of the graphene and the silicon dioxide, the mass ratio of the graphene oxide to the silica sol is preferably 1: (2 to 50), more preferably 1: (5-45), more preferably 1: (10-40), more preferably 1: (20-30).

the process and conditions of the ultrasonic dispersion are not particularly limited in the present invention, and the parameters of the ultrasonic dispersion known to those skilled in the art can be selected and adjusted according to the actual production situation, the compounding situation and the product performance, and the ultrasonic dispersion in the present invention is preferably an ultrasonic process with stirring. The ultrasonic frequency of the ultrasonic dispersion is preferably 500-5000 Hz, more preferably 1500-4000 Hz, and more preferably 2500-3000 Hz. The stirring speed of the ultrasonic dispersion is preferably 50-1000 r/min, more preferably 250-800 r/min, and more preferably 450-600 r/min. The time for ultrasonic dispersion is preferably 1-10 h, more preferably 3-8 h, and more preferably 5-6 h.

In order to ensure the uniform dispersion, integrity and refinement of the graphene and the silicon dioxide, and further improve the dispersibility and stability of the final product, the step 1) can be specifically as follows:

And (3) ultrasonically stirring the graphene oxide aqueous solution, and then dropwise adding silica sol into the graphene oxide aqueous solution to obtain a dispersion liquid.

the dropping speed is not particularly limited, and can be selected and adjusted by the skilled in the art according to the actual production condition, the product quality and the use requirement, and is preferably 5-50 mL/min, more preferably 15-40 mL/min, and more preferably 25-30 mL/min.

the invention further carries out ultrasonic dispersion on the dispersion liquid obtained in the step and the natural rubber again to obtain mixed slurry.

The addition amount of the natural rubber is not particularly limited in the present invention, and may be a conventional addition amount well known to those skilled in the art, and those skilled in the art can select and adjust the addition amount according to actual production conditions, product quality and use requirements, and the mass ratio of the graphene to the natural rubber in the present invention is preferably 1: (1 to 30), more preferably 1: (5-25), more preferably 1: (10-20).

In order to ensure the uniform dispersion, completeness and refinement of the graphene and silicon dioxide process and further improve the dispersibility and stability of the final product, the step 2) may specifically be:

And dropwise adding the dispersion liquid obtained in the step into the natural rubber under the condition of ultrasonic stirring again to obtain mixed slurry.

The process and conditions of the re-ultrasonic dispersion are not particularly limited in the present invention, and the parameters of the re-ultrasonic dispersion known to those skilled in the art can be selected and adjusted according to the actual production situation, the compounding situation and the product performance, and the re-ultrasonic dispersion in the present invention is preferably an ultrasonic process with stirring. The ultrasonic frequency of the secondary ultrasonic dispersion is preferably 500-5000 Hz, more preferably 1500-4000 Hz, and more preferably 2500-3000 Hz. The stirring speed of the secondary ultrasonic dispersion is preferably 50-1000 r/min, more preferably 250-800 r/min, and more preferably 450-600 r/min. The time for the secondary ultrasonic dispersion is preferably 1-10 h, more preferably 3-8 h, and more preferably 5-6 h.

the dropping speed is not particularly limited, and can be selected and adjusted by the skilled in the art according to the actual production condition, the product quality and the use requirement, and is preferably 5-50 mL/min, more preferably 15-40 mL/min, and more preferably 25-30 mL/min.

According to the invention, the mixed slurry obtained in the above step is reacted with a reducing agent to obtain the graphene/silica sol/natural rubber composite liquid.

The choice of the reducing agent is not particularly limited in the present invention, and may be a conventional reducing agent well known to those skilled in the art, and those skilled in the art can select and adjust the reducing agent according to actual production conditions, product quality and use requirements, and the reducing agent of the present invention preferably includes one or more of hydrazine hydrate, vitamin c, sodium borohydride, potassium hydroxide and ammonia gas, and more preferably hydrazine hydrate, vitamin c, sodium borohydride, potassium hydroxide or ammonia gas.

the amount of the reducing agent used in the present invention is not particularly limited, and may be the amount of a conventional reducing agent well known to those skilled in the art, and those skilled in the art can select and adjust the amount according to actual production conditions, product quality and use requirements, and the mass ratio of the graphene oxide to the reducing agent in the present invention is preferably 1: (1-10), more preferably 1: (3-8), more preferably 1: (5-6).

the process and conditions of the reaction are not particularly limited, and the process and parameters of the reduction reaction known to those skilled in the art can be selected and adjusted by those skilled in the art according to the actual production situation, compounding situation and product performance, and the reaction time is preferably 1-48 h, more preferably 5-40 h, more preferably 10-30 h, and more preferably 15-25 h. The reaction temperature is preferably 0-150 ℃, more preferably 20-120 ℃, more preferably 40-100 ℃, and more preferably 60-80 ℃.

finally, demulsifying the graphene/silica sol/natural rubber composite liquid obtained in the step to obtain the graphene/silica/natural rubber composite material

The demulsifier used in the present invention is not particularly limited in its choice, and may be any conventional demulsifier known to those skilled in the art, and may be selected and adjusted by those skilled in the art according to actual production conditions, product quality, and use requirements.

the amount of the demulsifier for demulsification is not particularly limited in the present invention, and may be any amount of conventional demulsifiers known to those skilled in the art, and those skilled in the art may select and adjust the demulsifier according to actual production conditions, product quality and use requirements, and the mass ratio of the graphene oxide to the demulsifier in the present invention is preferably 1: (1 to 100), more preferably 1: (10 to 90), more preferably 1: (30-70), more preferably 1: (40-60).

The demulsification process and conditions are not particularly limited, the demulsification process and parameters known by the technicians in the field can be used, the technicians in the field can select and adjust the demulsification process and parameters according to the actual production condition, the compounding condition and the product performance, and the demulsification time is preferably 1-100 min, more preferably 20-80 min, and more preferably 40-60 min. The temperature of the demulsification is preferably 10-50 ℃, more preferably 15-45 ℃, more preferably 20-40 ℃, and more preferably 25-35 ℃.

In order to ensure the uniform dispersion, integrity and refinement of the graphene and the silicon dioxide, and further improve the dispersibility and stability of the final product, the method preferably further comprises a post-treatment step after demulsification.

the process and parameters of the post-treatment are not particularly limited in the present invention, and may be selected and adjusted by those skilled in the art according to the actual production situation, the product quality and the use requirement, and the post-treatment of the present invention preferably includes one or more of filtration, washing and drying, and more preferably sequentially filtration, washing and drying. The filtration according to the invention is preferably suction filtration. The washing is preferably repeated, and specifically can be 3-6 times, and more preferably 4-5 times. The drying is preferably vacuum drying.

the invention also provides the application of the graphene/silicon dioxide/natural rubber composite material or the graphene/silicon dioxide/natural rubber composite material prepared by the preparation method in any one of the technical schemes in the aspect of rubber composite materials. The definition of the rubber composite material in the present invention is not particularly limited, and may be defined as a rubber composite material well known to those skilled in the art. The application mode of the graphene/silica/natural rubber composite material in the rubber composite material is not particularly limited, and the graphene/silica/natural rubber composite material can be applied in a conventional application mode well known to those skilled in the art, and the graphene/silica/natural rubber composite material can be selected and adjusted by the skilled in the art according to the actual application situation, the product requirement and the quality requirement.

The composite material prepared by the method for preparing the composite material by using the nano materials of the graphene oxide, the silica sol and the natural latex has the main component of SiO based on the white carbon black₂The main component of the silica sol is likewise SiO₂However, the white carbon black has the problem of uneven dispersion when added, and the silica particles in the silica sol are more uniformly dispersed, so that the silica is more uniformly dispersed in the graphene oxide sheet layer and further uniformly dispersed in the rubber by adopting a solution polymerization method, and the silica is added into the rubber matrix, so that the rolling resistance of the final rubber composite material can be improved, because the rolling resistance is mainly the movement of the tail end of the macromolecular chain microscopically, and the silica can play a role in fixing the movement of the molecular chain. Meanwhile, compared with vulcanized rubber of corresponding carbon black, the white carbon black has the advantages of high tearing strength, good insulativity, low heat generation, low rolling resistance and oil consumption for tires, good gripping power for dry and wet roads and the like.

the invention provides a graphene/silicon dioxide/natural rubber composite material, a preparation method thereof and application of the graphene/silicon dioxide/natural rubber composite material in a rubber composite material matrix. According to the invention, the graphene raw material, the silicon dioxide raw material and the natural rubber are firstly compounded to obtain the graphene/silicon dioxide/natural rubber composite material, in the material, silicon dioxide particles are attached to the graphene sheet layers, and the graphene sheet layers are inserted into the network of the natural rubber, so that the graphene and the silicon dioxide are uniformly dispersed in the natural rubber, and then the graphene/silicon dioxide/natural rubber composite material is used in the rubber composite material, so that the conductivity of the tire can be improved, the rolling resistance is reduced, and the tearing performance of the tire is improved.

More mainly, the invention creatively adopts silica sol as the raw material of silica, the main component of the silica sol is the same as that of the silica sol, and the silica sol is dispersion liquid of nano-scale silica particles in water or solvent, the invention creatively adopts silica sol as the raw material of silica, and then combines graphene oxide as the raw material of graphene, the graphene oxide/silica sol/natural latex is firstly compounded and then reduced, natural rubber is adopted as a combination substrate, the graphene oxide/silica sol/natural latex is mixed and then reduced by a reducing agent to prepare the graphene/silica sol/natural latex composite material, on one hand, the characteristics of consistent main components of silica sol and better silica sol dispersibility are utilized, the graphene oxide has better dispersibility in water, and preferably alkaline silica sol can be selected, the graphene oxide is acidic, dispersing and compounding the graphene oxide powder in water, mixing the graphene oxide powder and natural latex, reducing, demulsifying, washing and drying to obtain graphene and SiO₂The composite material has better dispersibility in natural latex. On the other hand, the lamellar structure of the graphene is well kept, so that the graphene is tightly combined with a rubber matrix, and the reinforcing and conducting effects of the graphene are effectively exerted.

the method for preparing the composite material by the graphene oxide, the silica sol and the natural latex through nano-mixing is simple, practical and suitable for industrial production and application, and the prepared graphene/silica/natural latex composite adhesive can be doped into a tire to improve the conductivity of the tire, reduce rolling resistance and improve the tearing performance of the tire.

experimental results show that when the graphene/silicon dioxide/natural rubber composite material is used in tires, the static electricity conducting capacity of the tires is improved, the static electricity conducting requirement is met, the abrasion is reduced by more than 5%, and the 300% stress at definite elongation is improved by 3%. The rolling resistance is reduced.

For further illustration of the present invention, the following will describe in detail a graphene/silica/natural rubber composite material, and a preparation method and an application thereof, with reference to the following examples, but it should be understood that these examples are implemented on the premise of the technical solution of the present invention, and the detailed embodiments and specific procedures are given, only for further illustration of the features and advantages of the present invention, but not for limitation of the claims of the present invention, and the scope of protection of the present invention is not limited to the following examples.