KR102529034B1 - 3-dimensional graphene-metal composite and manufacturing method of the same - Google Patents

Abstract

The present invention relates to a three-dimensional carbon-metal composite material and a method for manufacturing the same, and more particularly, through the fusion of carbon and metal micropowder, the electromagnetic wave absorption capacity and heat transfer rate are increased by forming a porous structure, thereby shielding electromagnetic waves and providing excellent heat dissipation. It relates to a multifunctional three-dimensional carbon-metal composite material having various functions and a manufacturing method thereof.

Description

3D carbon-metal composite material and its manufacturing method {3-DIMENSIONAL GRAPHENE-METAL COMPOSITE AND MANUFACTURING METHOD OF THE SAME}

The present invention relates to a three-dimensional carbon-metal composite material and a method for manufacturing the same, and more particularly, through the fusion of carbon and metal micropowder, the electromagnetic wave absorption capacity and heat transfer rate are increased by forming a porous structure, thereby shielding electromagnetic waves and providing excellent heat dissipation. It relates to a multifunctional three-dimensional carbon-metal composite material having various functions and a manufacturing method thereof.

Pollution due to electromagnetic waves in daily life is gradually increasing due to the miniaturization of electronic products and the development of information and communication devices. These electromagnetic waves cause malfunctions of peripheral devices or system errors, and can cause diseases in the human body, thereby causing direct damage, and for this reason, the development of electromagnetic wave shielding technology has become very important.

Therefore, the demand for electromagnetic wave shielding films that are attached to electronic products to shield electromagnetic waves is increasing, and the electromagnetic wave shielding ability of these electromagnetic wave shielding films can be expressed as the efficiency of electromagnetic wave shielding. It can be expressed as the sum of losses through surface reflection and multi-reflection.

Porous carbon-based materials with a three-dimensional nanonetwork structure, which are conventionally used as electromagnetic wave shielding materials, have attracted much attention due to their potential in various fields, including energy storage systems, solar cells, fuel cells, and absorbers of toxic organic solvents. These porous carbon-based materials can be processed into various dimensions to exhibit excellent electrical conductivity, chemical stability, and high surface area performance in the aforementioned nanotechnology field. In addition, the porous carbon-based material has a variety of pore size distributions and a surface area greater than 1000 m ² /g, so that it can be usefully used in various fields such as electrochemical devices.

Such a conventional porous carbon-based material consists only of contact by the pore wall, so the heat transfer rate is low, and the orientation of the carbon structure has anisotropy due to thermal characteristics, and electromagnetic wave shielding for use in next-generation communication and electronic devices such as 5G or 6G And there is a limit to simultaneously implementing heat dissipation characteristics.

Therefore, there is a need for a composite material that increases the heat transfer rate by increasing the contact area between the porous carbon-based materials and includes two or more functions.

Korean Patent Registration No. 10-1912908

The present invention has been made to solve the above-described problems, and an object of the present invention is a three-dimensional carbon-metal composite that efficiently implements electromagnetic wave shielding characteristics through the fusion of high electromagnetic wave shielding characteristics of carbon/metal itself and a porous structure. It is to provide a material and a manufacturing method thereof. In addition, it is to provide a multifunctional three-dimensional carbon-metal composite material having an excellent heat dissipation function by increasing the heat transfer rate according to the composite of graphene (or carbon nanotube), which is a highly crystalline carbon structure, and metal particles, and a manufacturing method thereof.

A three-dimensional carbon-metal composite material according to an embodiment of the present invention includes a carbon-based foam including a plurality of pores; and a metal micropowder located in the plurality of pores.

In one embodiment, the carbon-based foam is characterized in that it is formed of any one of crystalline carbon, graphene, carbon nanotubes and diamonds.

In one embodiment, the metal micropowder includes a micropowder of any one of copper (Cu), nickel (Ni), gold (Au), silver (Ag) and aluminum (Al) do.

In one embodiment, the size of the metal fine powder is characterized in that 50nm to 500㎛.

In one embodiment, the carbon-based foam is characterized in that it is provided in the form of a three-dimensional network.

A method for manufacturing a three-dimensional carbon-metal composite material according to an embodiment of the present invention includes preparing a mixture by mixing a carbon-based foam and a metal fine powder; and preparing a composite by subjecting the mixture to chemical vapor deposition (CVD).

In one embodiment, the step of preparing the composite is characterized by preparing the composite by thermal chemical vapor deposition (TCVD) of the mixture at a temperature of 70% to 100% of the melting point of the metal fine powder do.

In one embodiment, the step of preparing the composite is characterized by preparing the composite by subjecting the mixture to thermal chemical vapor deposition (TCVD) for a time of 5 hours or less.

In one embodiment, the chemical vapor deposition is characterized in that it is made in any one gas atmosphere of hydrogen, methane and inert gas.

In one embodiment, in the step of preparing the composite, the metal micropowder introduced into the pores of the carbon-based foam is sintered to form a network between the metal micropowder by surface melting. do.

According to the present invention, the copper micropowder is placed on the three-dimensional graphene form to increase the contact area and area between the components, thereby increasing the heat transfer rate and thereby increasing the heat dissipation function.

In addition, internal reflection and absorption are increased by the pores formed on the surface of the composite with graphene foam and copper particles, thereby generating an electromagnetic wave shielding effect.

1(a) is a view showing a carbon-based foam according to the present invention, FIG. 1(b) is a view showing a metal fine powder according to the present invention, and FIG. 1(c) is a 3-dimensional view according to the present invention It is a drawing showing a carbon-metal composite.
Figure 2 (a) is a picture of the porous carbon foam obtained in the example, Figure 2 (b) is a picture of the three-dimensional carbon-metal composite material obtained in the example, Figure 2 (c) is a three-dimensional carbon according to the present invention -It is a drawing showing a scanning electron microscope image (SEM) of a metal composite material.
3 is a graph showing electromagnetic wave shielding efficiency of an embodiment.

The present invention will be described in detail with reference to the accompanying drawings. Here, repeated descriptions and detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted. Embodiments of the present invention are provided to completely explain the present invention to those skilled in the art. Accordingly, the shapes and sizes of elements in the drawings may be exaggerated for clarity.

Throughout the specification, when a certain component is said to "include", it means that it may further include other components without excluding other components unless otherwise stated.

Hereinafter, a preferred embodiment is presented to aid understanding of the present invention. However, the following examples are only provided to more easily understand the present invention, and the content of the present invention is not limited by the examples.

<Three-dimensional carbon-metal composite>

1(a) is a view showing a carbon-based foam 10 according to the present invention, FIG. 1(b) is a view showing a metal fine powder 20 according to the present invention, and FIG. 1(c) shows It is a drawing showing the three-dimensional carbon-metal composite 100 according to the present invention.

Referring to FIG. 1 (a), the carbon-based foam 10 according to the present invention is a component that determines the external shape of the three-dimensional carbon-metal composite 100. The carbon-based foam 10 includes a plurality of pores and is provided in the form of a three-dimensional network. And, the carbon-based foam 10 may be formed of any one of crystalline carbon, graphene, carbon nanotube (CNT), and diamond.

Here, including a plurality of pores means that the carbon-based foam 10 is composed of pores and pore walls containing carbon materials.

And, the three-dimensional network refers to a structure in which several layers are formed by connecting carbon substrates on a two-dimensional plane having a thickness of nanometers (nm) to micrometers (μm). That is, the carbon-based foam 10 has a structure in which carbon substrates on a two-dimensional plane are connected to each other in a three-dimensional network, has pores formed by the three-dimensional carbon substrate network, and pores are connected to each other to form a continuous channel.

Since the carbon-based foam 10 according to the present invention is provided in a three-dimensional network structure including a plurality of pores, an electromagnetic wave shielding effect may be generated by absorbing electromagnetic waves by the porous structure.

The metal fine powder 20 may be provided in various shapes such as a spherical shape, a linear shape, and a plate shape, but referring to FIG. 1(b), the fine powder 20 is preferably provided in a spherical shape. In addition, the micropowder 20 according to the present invention may include any one of micropowder of copper (Cu), nickel (Ni), gold (Au), silver (Ag), and aluminum (Al) .

The metal fine powder according to the present invention may be formed in a size of 50 nm to 500 μm. The pore size can be controlled by controlling the size of the fine powder, but if the size is less than 50 nm, there is a problem that the fine powder may not be completely melted at a low temperature and no pores are formed. In addition, there may be a problem that the metal fine powder does not penetrate into the pores of the carbon-based foam. And, when the size of the fine powder is 500 μm or more, the bonding is weak because the contact area between the fine powders is small, and thus may not have sufficient physical strength.

2(a) is a photograph of the porous carbon foam obtained in the example, FIG. 2(b) is a photograph of the three-dimensional carbon-metal composite material obtained in the example, and FIG. It is a diagram showing a scanning electron microscope image (SEM) of a dimensional carbon-metal composite material.

1(c) and 2(c), the surface of the three-dimensional carbon-metal composite material 100 is provided in a form in which metal fine powder 20 is filled in pores formed in the carbon-based foam 10. can At this time, the metal micropowder 20 is not positioned in all pores formed in the carbon-based foam 10, and pores in which the metal micropowder 20 is not positioned may be formed. And, it can be seen that the metal fine powder 20 also has a porous structure.

Therefore, the surface of the composite material 100 according to the present invention may be provided with a carbon substrate structure or a carbon-metal structure in which a plurality of pores are formed. Since the surface of the composite material 100 is formed of a carbon substrate having a porous structure, the electromagnetic wave reflectance is reduced, thereby increasing the electromagnetic wave shielding rate of the three-dimensional carbon-metal composite material 100 according to the present invention.

<Method for producing 3-dimensional carbon-metal composite>

The method for manufacturing a three-dimensional carbon-metal composite material according to the present invention includes preparing a mixture (S100) and preparing a composite (S200).

The step of preparing the mixture (S100) is a step of mixing the carbon-based foam and the metal fine powder. Here, the carbon-based foam and the metal fine powder are mixed by a vibrator, and the metal fine powder may be drawn into the pores of the carbon-based foam by the vibration.

The pore diameter of the carbon-based foam is tens to hundreds of micrometers, whereas the metal micropowder is formed with a diameter of nanometers to micrometers. Therefore, when the metal micropowder is applied to the carbon-based foam, the metal micropowder is inserted into and positioned between the layers of the two-dimensional carbon substrate through the pores of the carbon-based foam.

The vibrator can be operated for 5 to 15 minutes. When mixing for less than 5 minutes, the amount of metal fine powder not drawn into the pores is large, and when the mixing time exceeds 15 minutes, the increased effect is insignificant.

The step of preparing the composite (S200) is a step of chemical vapor deposition (CVD) of the mixture. Chemical vapor deposition is TCVD (Thermal CVD), APCVD (Atmospheric pressure CVD), LPCVD (Low-pressure CVD), UHVCVD (Ultrahigh vacuum CVD), AACVD (Aerosol assisted CVD), DLICVD (Direct liquid injection CVD), MPCVD (Microwave CVD) plasma-assisted CVD), PECVD (Plasma Enhanced CVD), RPECVD (Remote plasma-enhanced CVD), ALCVD (Atomic layer CVD), HWCVD (Hot wire CVD), CatCVD (Catalytic CVD), HFCVD (hot filament CVD), MOCVD (Metalorganic CVD), HPCVD (Hybrid Physical-CVD), RTCVD (Rapid Thermal CVD), and VPE (Vapor Phase Epitaxy).

In one embodiment, the method for manufacturing a three-dimensional carbon-metal composite material according to the present invention may sinter the mixture using thermal chemical vapor deposition (TCVD).

In the step of preparing the composite (S200), the composite may be prepared by thermal chemical vapor deposition at a temperature in the range of 70% to 100% of the melting point of the metal micropowder for 5 hours or less. At this time, the thermal chemical vapor deposition apparatus is characterized in that it is made in a gas atmosphere of any one of hydrogen, methane, and an inert gas, and in one embodiment, the inert gas includes argon gas, nitrogen gas, and the like.

Therefore, in the step of preparing the mixture (S100), pores (or networks) may be formed between the metal micropowders by surface melting while the metal micropowder introduced into the pores of the carbon-based foam is sintered.

If the temperature of the thermal chemical vapor deposition apparatus is less than 70% of the melting point of the metal micropowder, the surface of the metal micropowder is not melted and a bond is not formed, so a porous structure may not be formed, and 100% of the melting point of the metal micropowder If it exceeds , the phase of the metal micropowder changes to a liquid, and a porous structure may not be formed.

<Example>

After preparing the graphene foam, the composite is prepared according to the manufacturing method of the three-dimensional carbon-metal composite of the present invention.

To manufacture graphene foam, a porous nickel foam with a size of 10 * 50 * 1㎛ is put into a thermal chemical vapor deposition (TCVD) device, and then reacted for 30 minutes at a temperature of 1000 ° C in a hydrogen and methane gas atmosphere. Graphene is synthesized on the surface of nickel foam. Then, the porous nickel foam synthesized with graphene is etched with nickel in a 40% nitric acid solution to prepare a porous graphene foam.

Next, in the preparation of the carbon-metal composite, porous graphene foam and 1 μm copper powder are first put in a boat and mixed for 10 minutes using a vibrator. The mixed porous graphene foam and copper powder were put into a thermal chemical vapor deposition apparatus in an atmosphere of hydrogen and methane gas, reacted at 1000 ° C. for 30 minutes, and then cooled naturally to obtain a carbon-metal composite.

<Experimental example>

3 is a graph showing electromagnetic wave shielding efficiency of an embodiment, and Table 1 below is a conversion table obtained by converting the shielding rate of FIG. 3 into a percentage (%).

Referring to FIG. 3, it shows an electromagnetic wave shielding rate of 80 dB on average at a frequency of 0 to 20 GHz.

Shielding Effectiveness (dB) Shielding Efficiency ( % ) 0 0 10 90 20 99 30 99.39 40 99.99 50 99.999 60 99.9999 70 99.99999 80 99.999999 90 99.9999999

Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art will variously modify and change the present invention within the scope not departing from the spirit and scope of the present invention described in the claims below. You will understand that it can be done.

100: three-dimensional carbon-metal complex
10: form
20: fine powder

Claims (10)

In the three-dimensional carbon-metal composite material,
A carbon-based foam including a plurality of pores and formed of graphene; and
Including; metal micropowder located in the plurality of pores,
Here, the size of the metal fine powder is 1 μm to 500 μm,
Characterized in that the three-dimensional carbon-metal composite material has an average electromagnetic shielding rate of 80 dB at a frequency of 0 to 20 GHz,
Three-dimensional carbon-metal composites.
delete According to claim 1,
The metal fine powder,
A three-dimensional carbon-metal composite material comprising a micropowder of any one of copper (Cu), nickel (Ni), gold (Au), silver (Ag) and aluminum (Al).
delete According to claim 1,
The carbon-based foam,
Characterized in that it is provided in the form of a three-dimensional network (network), a three-dimensional carbon-metal composite material.
delete delete delete delete delete

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