阅读说明：本技术 一种石墨烯复合材料、其制备方法及应用 (Graphene composite material, preparation method and application thereof ) 是由 刘洋 于 2020-12-17 设计创作，主要内容包括：本发明涉及一种石墨烯复合材料、其制备方法及应用,包括配制氧化石墨烯分散液,搅拌状态下将氮化物逐步加入到所述氧化石墨烯分散液,继续搅拌加入分散稳定剂,得到氧化石墨烯混合物料,保持搅拌的前提下,将所述氮化物、氧化石墨烯混合物料通过喷雾干燥机制备成核壳结构的氮化物-氧化石墨烯的复合材料；将制备的所述核壳结构的氮化物-氧化石墨烯的复合材料以还原方式制备成为氮化物-石墨烯复合材料。本发明将氧化石墨烯均匀包覆在氮化物材料表面,所得到的核壳结构复合材料能够稳定存在,石墨烯复合材料一体成型,生产成本低,且电导率以及热导率实现明显的提高。(The invention relates to a graphene composite material, a preparation method and application thereof, which comprises the steps of preparing a graphene oxide dispersion liquid, gradually adding nitride into the graphene oxide dispersion liquid under the stirring state, continuously stirring and adding a dispersion stabilizer to obtain a graphene oxide mixed material, and preparing the nitride and graphene oxide mixed material into a nitride-graphene oxide composite material with a core-shell structure by a spray dryer under the stirring condition; and preparing the prepared nitride-graphene oxide composite material with the core-shell structure into a nitride-graphene composite material in a reduction mode. According to the invention, graphene oxide is uniformly coated on the surface of the nitride material, the obtained core-shell structure composite material can exist stably, the graphene composite material is integrally formed, the production cost is low, and the electric conductivity and the thermal conductivity are obviously improved.)

1. A preparation method of a graphene composite material is characterized by comprising the following steps: the method comprises the following steps:

(1) preparing a graphene oxide dispersion liquid, gradually adding a nitride into the graphene oxide dispersion liquid under a stirring state, continuously stirring and adding a dispersion stabilizer to obtain a graphene oxide mixed material, and preparing the nitride and graphene oxide mixed material into a core-shell nitride-graphene oxide composite material by a spray dryer under the premise of keeping stirring;

(2) and preparing the prepared nitride-graphene oxide composite material with the core-shell structure into a nitride-graphene composite material in a reduction mode.

2. The method for preparing the graphene composite material according to claim 1, wherein: the graphene oxide dispersion liquid in the step (1) is one or more of ultrasonic dispersion, mechanical grinding or high-speed stirring dispersion.

3. The method for preparing the graphene composite material according to claim 2, wherein: the concentration range of the graphene oxide dispersion liquid in the step (1) is 3-8 mg/ml.

4. The method for preparing a graphene composite material according to claim 3, wherein: the rotating speed range of the continuous stirring in the step (1) is 100-800 rpm.

5. The method for preparing the graphene composite material according to claim 4: the method is characterized in that: the air inlet temperature range of the spray drying in the step (1) is 20-220 ℃, and the air outlet temperature range is 50-100 ℃.

6. The method for preparing the graphene composite material according to claim 5: the method is characterized in that: the reduction mode in the step (2) is one or more of laser reduction, thermal reduction or high-pressure reduction.

7. A graphene composite material, characterized in that: prepared by the preparation method of the graphene composite material according to any one of claims 1 to 6.

8. The graphene composite material according to claim 7, wherein: the graphene composite material takes nitride as an inner shell, and graphene is coated on the surface of the nitride to form a core-shell structure of an outer core.

9. The graphene composite material according to claim 8, wherein: the average particle size range of the graphene composite material is 5-100 micrometers.

10. Use of the graphene composite material of any one of claims 7 to 9 in electronic device heat dissipation or photovoltaic power generation.

Technical Field

The invention relates to the technical field of heat dissipation and heat conduction, in particular to a graphene composite material, and a preparation method and application thereof.

Background

Graphene (GNPs) is a carbon material having a planar two-dimensional structure, has excellent electrical and thermal conductivity, has a large specific surface area, high transparency and good mechanical properties, and is widely used in the fields of electronic devices, biosensors, transparent conductive films, composite materials and the like.

For example, CN 107869047 a in the prior art discloses a graphene-boron nitride composite material and a preparation method thereof, which utilize the swelling and fusion effect of a graphene oxide coating on the surface of boron nitride to realize the crosslinking of boron nitride fibers. Graphene oxide is used as a sizing agent and a cross-linking agent, and is further reduced by an organic reducing agent to form a graphene layer.

As another example, another application document TW20184076A discloses a semiconductor structure having a graphene layer, wherein the semiconductor may be gallium nitride, grown into graphene on a copper foil by a metal organic chemical vapor deposition method; cleaning the semiconductor substrate, and drying by using nitrogen flow; transferring the graphene onto a semiconductor substrate, etching a copper foil, fixing the graphene layer, and cleaning with acetone; etching the surface of the graphene layer to form holes; and depositing a gallium nitride semiconductor on the surface of the graphene layer.

The composite materials prepared in the prior art have certain problems in stability due to simple coating or mixing. In addition, reducing agents such as hydrogen iodide and hydrazine hydrate involved in the reduction process belong to toxic and harmful chemical reagents, and do not accord with the development concept of green chemistry.

Disclosure of Invention

In order to overcome the technical defects in the prior art, the invention provides a graphene composite material, a preparation method and application thereof.

In order to solve the technical problems, the technical scheme of the graphene composite material, the preparation method and the application thereof provided by the invention is as follows:

in a first aspect, the embodiment of the invention discloses a preparation method of a graphene composite material, which comprises the following steps:

(1) preparing a graphene oxide dispersion liquid, gradually adding a nitride into the graphene oxide dispersion liquid under a stirring state, continuously stirring and adding a dispersion stabilizer to obtain a graphene oxide mixed material, and preparing the nitride and graphene oxide mixed material into a core-shell nitride-graphene oxide composite material by a spray dryer under the premise of keeping stirring;

(2) and preparing the prepared nitride-graphene oxide composite material with the core-shell structure into a nitride-graphene composite material in a reduction mode.

In any of the above schemes, it is preferable that the graphene oxide dispersion liquid in step (1) is one or more of ultrasonic dispersion, mechanical grinding or high-speed stirring dispersion.

In any of the above embodiments, the concentration of the graphene oxide dispersion liquid in the step (1) is preferably in a range of 3 to 8 mg/ml.

In any of the above embodiments, the rotation speed of the continuous stirring in the step (1) is preferably in the range of 100 to 800 rpm.

In any of the above schemes, preferably, the air inlet temperature range of the spray drying in the step (1) is 20-220 ℃, and the air outlet temperature range is 50-100 ℃.

In any of the above schemes, preferably, the reduction mode in step (2) is one or more of laser reduction, thermal reduction or high pressure reduction.

Compared with the prior art, the preparation method of the graphene composite material has the advantages that the dispersion solvent of the graphene oxide is only aqueous solution, the reduction of the graphene oxide does not relate to toxic and harmful substances, the graphene oxide can be fully reduced by laser, heating or electromagnetism, the reduction effect is better than that of the prior art, and the electric conductivity and the thermal conductivity are obviously improved.

In a second aspect, the graphene composite material is prepared by the preparation method of the graphene composite material.

In any of the above schemes, preferably, the graphene composite material uses a nitride as an inner shell, and graphene is coated on the surface of the nitride to form a core-shell structure of an outer core.

In any of the above embodiments, preferably, the average particle size of the graphene composite material is in a range of 5 to 100 micrometers.

Compared with the prior art, the graphene composite material disclosed by the invention has the advantages that the graphene oxide is uniformly coated on the surface of the nitride material by adopting a spray drying technology, the obtained core-shell structure composite material can stably exist, the operation is simple, the graphene oxide is integrally formed, and the production cost is low.

In a third aspect, the graphene composite material is applied to heat dissipation of electronic devices or photovoltaic power generation.

Compared with the prior art, the graphene composite material disclosed by the invention is applied to heat dissipation of electronic devices or photovoltaic power generation, graphene oxide is uniformly coated on the surface of a nitride material by adopting a spray drying technology, the obtained core-shell structure composite material can stably exist, the operation is simple, the graphene oxide is integrally formed, and the production cost is low.

The dispersion solvent of the graphene oxide is only aqueous solution, the reduction of the graphene oxide does not relate to toxic and harmful substances, the graphene oxide can be fully reduced by laser, heating or electromagnetism, the reduction effect is better than that of the prior art, and the electric conductivity and the thermal conductivity are obviously improved.

Drawings

The drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification.

Fig. 1 is a schematic view of a preparation process of a graphene composite material according to the present invention.

Fig. 2 is a schematic structural diagram of a graphene composite material according to the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In order to achieve the purpose of obviously improving the electric conductivity and the thermal conductivity, the invention provides a graphene composite material, wherein a nitride is used as an inner shell, graphene is coated on the surface of the nitride to form an outer core to form a core-shell structure, and the average particle size of the graphene composite material is 5-100 micrometers.

The invention also provides a preparation method of the graphene composite material, which comprises the following steps: the adopted technical scheme is as follows:

(1) preparing a graphene oxide dispersion liquid by ultrahigh-speed stirring and dispersing, stirring the graphene oxide dispersion liquid to form a central vortex, gradually adding a nitride into the graphene oxide dispersion liquid under a stirring state, and continuously stirring and adding a dispersion stabilizer to obtain a graphene oxide mixed material; preparing the nitride-graphene oxide material with a core-shell structure by using the nitride-graphene oxide mixed material through a spray dryer under the premise of keeping stirring;

(2) and performing reduction reaction on the prepared nitride-graphene oxide material with the core-shell structure to prepare nitride-graphene oxide.

The concentration of the graphene oxide dispersion liquid in the step (1) is 3-8 mg/ml; the graphene oxide dispersion liquid is one or more of ultrasonic dispersion, mechanical grinding or high-speed stirring dispersion.

The concentration range of the graphene oxide dispersion liquid in the step (1) is 3-8 mg/ml; the continuous stirring rotating speed range in the step (1) is 100-800 rpm.

The air inlet temperature range of the spray drying in the step (1) is 20-220 ℃, and the air outlet temperature range is 50-100 ℃.

The reduction mode in the step (2) is one or more of laser reduction, thermal reduction or high-pressure reduction.

The invention also provides an application of the graphene composite material, and the graphene composite material is applied to the fields of electronic product heat dissipation, photovoltaic power generation and the like.

For better understanding of the above technical solutions, the technical solutions of the present invention will be described in detail below with reference to the drawings and the detailed description of the present invention.

Example 1:

as shown in fig. 1 and fig. 2, an embodiment of the present invention discloses a preparation method of a graphene composite material, in which graphene oxide dispersion liquid with a concentration of 5mg/ml is prepared by ultrasonic dispersion, an ultrasonic treatment power is 80W, and a sheet diameter of graphene oxide in the obtained graphene oxide dispersion liquid is 5 micrometers; gradually adding boron nitride powder into the graphene oxide dispersion liquid through mechanical stirring, stirring the graphene oxide dispersion liquid to form a central vortex, adding the boron nitride powder into the center of the vortex, and fully mixing and dispersing at the rotating speed of 600 rpm; on the premise of keeping stirring, preparing the boron nitride-graphene oxide powder material with a core-shell structure from the boron nitride and graphene oxide mixture through a spray dryer, wherein the stirring speed of the spray dryer is 200rpm, the air inlet temperature is 20 ℃, and the air outlet temperature is 90 ℃;

the prepared boron nitride-graphene oxide powder material is prepared into a boron nitride-graphene composite material by a laser reduction method, the laser reduction time is 10s, and the laser power is 5W.

The dispersion solvent of the graphene oxide is only aqueous solution, the reduction of the graphene oxide does not relate to toxic and harmful substances, the graphene oxide can be fully reduced through laser, heating or electromagnetism, the reduction effect is better than that of the prior art, the electric conductivity and the thermal conductivity are obviously improved, the spray drying technology is adopted, the graphene oxide is uniformly coated on the surface of the nitride material, the obtained core-shell structure composite material can stably exist, the operation is simple, the graphene oxide is integrally formed, and the production cost is low.

Example 2:

as shown in fig. 1 and fig. 2, an embodiment of the present invention discloses a preparation method of a graphene composite material, which includes preparing a graphene oxide dispersion liquid with a concentration of 3mg/ml by ultra-high speed stirring and dispersing, wherein a stirring speed is 400krpm, and a sheet diameter of graphene oxide in the obtained graphene oxide dispersion liquid is 30 micrometers; gradually adding the gallium nitride flaky microcrystal into the graphene oxide dispersion liquid through mechanical stirring, stirring the graphene oxide dispersion liquid to form a central vortex, adding the gallium nitride flaky microcrystal into the center of the vortex, and fully mixing and dispersing at the rotating speed of 800rpm of mechanical stirring; stirring was continued and 0.01mg/ml of polyoxyethylene octylphenol ether-10 (OP10), a dispersion stabilizer, was added; preparing the gallium nitride and graphene oxide mixed material into a gallium nitride-graphene oxide flaky material with a core-shell structure by a spray dryer on the premise of keeping stirring; the stirring speed of the spray dryer is 100rpm, the air inlet temperature is 160 ℃, and the air outlet temperature is 70 ℃;

placing the prepared flaky material of gallium nitride-graphene oxide in a hydrogen-argon volume ratio of 1: 3, heating the mixed gas to 400 ℃ for 1h to prepare the gallium nitride-graphene oxide.

The dispersion solvent of the graphene oxide is only aqueous solution, the reduction of the graphene oxide does not relate to toxic and harmful substances, the graphene oxide can be fully reduced through laser, heating or electromagnetism, the reduction effect is better than that of the prior art, the electric conductivity and the thermal conductivity are obviously improved, the spray drying technology is adopted, the graphene oxide is uniformly coated on the surface of the nitride material, the obtained core-shell structure composite material can stably exist, the operation is simple, the graphene oxide is integrally formed, and the production cost is low.

Example 3:

as shown in fig. 1 and fig. 2, an embodiment of the present invention discloses a preparation method of a graphene composite material, in which graphene oxide dispersion liquid with a concentration of 8mg/ml is prepared by ultra-high speed stirring and dispersion, and the sheet diameter of graphene oxide in the obtained graphene oxide dispersion liquid is 70 μm; gradually adding aluminum nitride into the dispersion liquid through mechanical stirring, stirring the graphene oxide dispersion liquid to form a central vortex, adding the gallium nitride flaky microcrystal into the center of the vortex, fully mixing, and further grinding in a colloid mill; adding 0.01mg/ml of dispersion stabilizer OP10 during grinding; preparing the aluminum nitride and graphene oxide mixed material into a core-shell aluminum nitride-graphene oxide flaky material by a spray dryer on the premise of keeping stirring; the stirring speed of the spray dryer is 500rpm, the air inlet temperature is 100 ℃, and the air outlet temperature is 50 ℃;

and (3) placing the prepared aluminum nitride-graphene oxide material in a microwave oven for 1000W for 1-2S to prepare the aluminum nitride-graphene oxide material.

The dispersion solvent of the graphene oxide is only aqueous solution, the reduction of the graphene oxide does not relate to toxic and harmful substances, the graphene oxide can be fully reduced through laser, heating or electromagnetism, the reduction effect is better than that of the prior art, the electric conductivity and the thermal conductivity are obviously improved, the spray drying technology is adopted, the graphene oxide is uniformly coated on the surface of the nitride material, the obtained core-shell structure composite material can stably exist, the operation is simple, the graphene oxide is integrally formed, and the production cost is low.

Example 4:

as shown in fig. 1 and fig. 2, an embodiment of the present invention discloses a preparation method of a graphene composite material, which includes preparing a graphene oxide dispersion liquid with a concentration of 5mg/ml by ultra-high speed stirring and dispersing, wherein a stirring speed is 350krpm, and a sheet diameter of graphene oxide in the obtained graphene oxide dispersion liquid is 100 micrometers; gradually adding the gallium nitride flaky microcrystal into the dispersion liquid through mechanical stirring, stirring the graphene oxide dispersion liquid to form a central vortex, adding the gallium nitride flaky microcrystal into the center of the vortex, and fully mixing and dispersing at the rotating speed of 800rpm of mechanical stirring; preparing the gallium nitride and graphene oxide mixed material into a gallium nitride-graphene oxide flaky material with a core-shell structure by a spray dryer on the premise of keeping stirring; the stirring speed of the spray dryer is 200rpm, the air inlet temperature is 220 ℃, and the air outlet temperature is 100 ℃;

adding water into a high-pressure stirring container, putting the prepared gallium nitride-graphene oxide material into the high-pressure stirring container, sealing the stirring container, injecting hydrogen into the water, pressurizing to 350MPa, stirring at the rotating speed of 400rpm, and keeping stirring for 2 hours under the pressure to prepare the gallium nitride-graphene oxide.

The dispersion solvent of the graphene oxide is only aqueous solution, the reduction of the graphene oxide does not relate to toxic and harmful substances, the graphene oxide can be fully reduced through laser, heating or electromagnetism, the reduction effect is better than that of the prior art, the electric conductivity and the thermal conductivity are obviously improved, the spray drying technology is adopted, the graphene oxide is uniformly coated on the surface of the nitride material, the obtained core-shell structure composite material can stably exist, the operation is simple, the graphene oxide is integrally formed, and the production cost is low.

Example 5:

as shown in fig. 1 and fig. 2, an embodiment of the invention discloses a preparation method of a graphene composite material, which comprises the steps of preparing a graphene oxide dispersion liquid with a concentration of 4mg/ml by ultrasonic dispersion, wherein the ultrasonic treatment power is 90W, and the sheet diameter of graphene oxide in the obtained graphene oxide dispersion liquid is 50 micrometers; gradually adding boron nitride powder into the graphene oxide dispersion liquid through mechanical stirring, stirring the graphene oxide dispersion liquid to form a central vortex, adding the boron nitride powder into the center of the vortex, and fully mixing and dispersing at the rotating speed of 500 rpm; on the premise of keeping stirring, preparing the boron nitride-graphene oxide powder material with a core-shell structure by using a spray dryer, wherein the stirring speed of the spray dryer is 200rpm, the air inlet temperature is 50 ℃, and the air outlet temperature is 100 ℃;

the prepared boron nitride-graphene oxide powder material is prepared into a boron nitride-graphene composite material by a laser reduction method, the laser reduction treatment time is 8s, and the laser power is 4W.

The dispersion solvent of the graphene oxide is only aqueous solution, the reduction of the graphene oxide does not relate to toxic and harmful substances, the graphene oxide can be fully reduced through laser, heating or electromagnetism, the reduction effect is better than that of the prior art, the electric conductivity and the thermal conductivity are obviously improved, the spray drying technology is adopted, the graphene oxide is uniformly coated on the surface of the nitride material, the obtained core-shell structure composite material can stably exist, the operation is simple, the graphene oxide is integrally formed, and the production cost is low.

Example 6:

as shown in fig. 1 and fig. 2, an embodiment of the present invention discloses a preparation method of a graphene composite material, which includes preparing a graphene oxide dispersion liquid with a concentration of 5mg/ml by ultra-high speed stirring and dispersing, wherein a stirring speed is 600krpm, and a sheet diameter of graphene oxide in the obtained graphene oxide dispersion liquid is 60 micrometers; gradually adding the gallium nitride flaky microcrystal into the graphene oxide dispersion liquid through mechanical stirring, stirring the graphene oxide dispersion liquid to form a central vortex, adding the gallium nitride flaky microcrystal into the center of the vortex, and fully mixing and dispersing at the rotating speed of 800rpm of mechanical stirring; stirring was continued and 0.01mg/ml of polyoxyethylene octylphenol ether-10 (OP10), a dispersion stabilizer, was added; preparing the gallium nitride and graphene oxide mixed material into a gallium nitride-graphene oxide flaky material with a core-shell structure by a spray dryer on the premise of keeping stirring; the stirring speed of the spray dryer is 100rpm, the air inlet temperature is 200 ℃, and the air outlet temperature is 80 ℃;

placing the prepared flaky material of gallium nitride-graphene oxide in a hydrogen-argon volume ratio of 1: 3, heating the mixed gas to 400 ℃ for 1h to prepare the gallium nitride-graphene oxide.

The dispersion solvent of the graphene oxide is only aqueous solution, the reduction of the graphene oxide does not relate to toxic and harmful substances, the graphene oxide can be fully reduced through laser, heating or electromagnetism, the reduction effect is better than that of the prior art, the electric conductivity and the thermal conductivity are obviously improved, the spray drying technology is adopted, the graphene oxide is uniformly coated on the surface of the nitride material, the obtained core-shell structure composite material can stably exist, the operation is simple, the graphene oxide is integrally formed, and the production cost is low.

Example 7:

as shown in fig. 1 and fig. 2, an embodiment of the present invention discloses a preparation method of a graphene composite material, in which a graphene oxide dispersion liquid with a concentration of 7mg/ml is prepared by ultra-high speed stirring and dispersion, and the sheet diameter of graphene oxide in the obtained graphene oxide dispersion liquid is 60 micrometers; gradually adding aluminum nitride into the dispersion liquid through mechanical stirring, stirring the graphene oxide dispersion liquid to form a central vortex, adding the gallium nitride flaky microcrystal into the center of the vortex, fully mixing, and further grinding in a colloid mill; adding 0.01mg/ml of dispersion stabilizer OP10 during grinding; preparing the aluminum nitride and graphene oxide mixed material into a core-shell aluminum nitride-graphene oxide flaky material by a spray dryer on the premise of keeping stirring; the stirring speed of the spray dryer is 500rpm, the air inlet temperature is 220 ℃, and the air outlet temperature is 100 ℃;

and (3) placing the prepared aluminum nitride-graphene oxide material in a microwave oven for 1000W for 1-2S to prepare the aluminum nitride-graphene oxide material.

The dispersion solvent of the graphene oxide is only aqueous solution, the reduction of the graphene oxide does not relate to toxic and harmful substances, the graphene oxide can be fully reduced through laser, heating or electromagnetism, the reduction effect is better than that of the prior art, the electric conductivity and the thermal conductivity are obviously improved, the spray drying technology is adopted, the graphene oxide is uniformly coated on the surface of the nitride material, the obtained core-shell structure composite material can stably exist, the operation is simple, the graphene oxide is integrally formed, and the production cost is low.

Example 8:

as shown in fig. 1 and fig. 2, an embodiment of the present invention discloses a preparation method of a graphene composite material, which includes preparing a graphene oxide dispersion liquid with a concentration of 4mg/ml by ultra-high speed stirring and dispersing, wherein a stirring speed is 500krpm, and a sheet diameter of graphene oxide in the obtained graphene oxide dispersion liquid is 100 micrometers; gradually adding the gallium nitride flaky microcrystal into the dispersion liquid through mechanical stirring, stirring the graphene oxide dispersion liquid to form a central vortex, adding the gallium nitride flaky microcrystal into the center of the vortex, and fully mixing and dispersing at the rotating speed of 800rpm of mechanical stirring; preparing the gallium nitride and graphene oxide mixed material into a gallium nitride-graphene oxide flaky material with a core-shell structure by a spray dryer on the premise of keeping stirring; the stirring speed of the spray dryer is 200rpm, the air inlet temperature is 210 ℃, and the air outlet temperature is 90 ℃;

adding water into a high-pressure stirring container, putting the prepared gallium nitride-graphene oxide material into the high-pressure stirring container, sealing the stirring container, injecting hydrogen into the water, pressurizing to 350MPa, stirring at the rotating speed of 400rpm, and keeping stirring for 2 hours under the pressure to prepare the gallium nitride-graphene oxide.

The dispersion solvent of the graphene oxide is only aqueous solution, the reduction of the graphene oxide does not relate to toxic and harmful substances, the graphene oxide can be fully reduced through laser, heating or electromagnetism, the reduction effect is better than that of the prior art, the electric conductivity and the thermal conductivity are obviously improved, the spray drying technology is adopted, the graphene oxide is uniformly coated on the surface of the nitride material, the obtained core-shell structure composite material can stably exist, the operation is simple, the graphene oxide is integrally formed, and the production cost is low.

Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that various changes, modifications and substitutions can be made without departing from the spirit and scope of the invention as defined by the appended claims. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.