WO2024139811A1

WO2024139811A1 - Magnetic composite materials, methods of preparing magnetic composite materials, and electronic devices

Info

Publication number: WO2024139811A1
Application number: PCT/CN2023/131733
Authority: WO
Inventors: Lei Wang; Jinbiao SHU; Yang KONG; Along CHEN; Zhiji DENG; Ming Liu
Original assignee: Zhejiang Dahua Technology Co Ltd
Current assignee: Zhejiang Dahua Technology Co Ltd
Priority date: 2022-12-30
Filing date: 2023-11-15
Publication date: 2024-07-04
Anticipated expiration: 2025-06-30
Also published as: EP4595721A1; EP4595721A4

Abstract

Embodiments of the present disclosure may provide a magnetic composite material, a method of preparing a magnetic composite material, and an electronic device including the magnetic composite material. The magnetic composite material may comprise a carbon nanomaterial cluster and nano metal sulfide. The carbon nanomaterial cluster may include a plurality of carbon nanomaterial units. The nano metal sulfide may be mixed into the carbon nanomaterial cluster. The nano metal sulfide may include nano tungsten disulfide and/or nano zinc sulfide, and one of the plurality of carbon nanomaterial units may include nano carbon crystal and/or nano graphene.

Description

MAGNETIC COMPOSITE MATERIALS, METHODS OF PREPARING MAGNETIC COMPOSITE MATERIALS, AND ELECTRONIC DEVICES

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Chinese patent application No. 202211743441.1, filed on December 30, 2022, and Chinese patent application No. 202310401306.7, filed on April 14, 2023, the entire contents of each of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to the field of electromagnetic wave-absorbing materials, and in particular, to a magnetic composite material, a method of preparing a magnetic composite material, and an electronic device including the magnetic composite material.

BACKGROUND

With the rapid development of electronic information technology, electronic devices with high power and high rate are developing towards high integration and miniaturization. However, as an integration level increases and size (s) decreases, an electronic device is inevitably affected by electromagnetic radiation interference. Electromagnetic radiation (s) not only harm human health but also have a highly sensitive impact on electronic components in the electronic device. Any small electromagnetic interference has a probability of causing a malfunction of the electronic device.

In order to prevent malfunctions in the electronic device caused by the electromagnetic radiation interference, a metal-based material (s) is used fora shielding enclosure for an electronic device. However, the metal-based material has drawbacks such as high density, narrow absorption bandwidth, poor thermal stability, etc. Additionally, a large amount of electromagnetic wave absorbers are often added to the shielding enclosure including the metal-based material to meet absorption bandwidth requirements. These electromagnetic wave absorbers result in decreased performance and reduced lifespan of the shielding enclosure.

SUMMARY

One or more embodiments of the present disclosure may provide a magnetic composite material. The magnetic composite material may comprise a carbon nanomaterial cluster and nano metal sulfide. The carbon nanomaterial cluster may include a plurality of carbon nanomaterial units. The nano metal -sulfide may be mixed with the carbon nanomaterial cluster. The nano metal sulfide may include nano tungsten disulfide and/or nano zinc sulfide, and one of the plurality of carbon nanomaterial units may include nano carbon crystal and/or nano graphene.

In some embodiments, the carbon nanomaterial cluster may be a nano carbon crystal cluster comprising a plurality of the nano carbon crystals, and the nano metal sulfide may be the nano tungsten disulfide, wherein the nano tungsten disulfide may be adhered to a surface of each of at least a portion of the plurality of the nano carbon crystals, and at least a portion of interstices of the nano carbon crystal cluster may be filled with the nano tungsten disulfide.

In some embodiments, the nano tungsten disulfide may be in the form of a cube and have a maximum diameter in a range of 3 nm-6 nm and an intermediate diameter in a range of 2 nm-5 nm.

In some embodiments, one of the plurality of the nano carbon crystals may have a pore channel structure.

In some embodiments, one of the plurality of the nano carbon crystals may be the form of three-dimensional pyramid, and a ratio of the maximum diameter of the nano tungsten disulfide to an edge length of the nano carbon crystal may be in a range of 1: 1.8-1: 3.

In some embodiments, a mass ratio of the nano tungsten disulfide to the cluster of nano carbon crystals may be in a range of 1: 1.3-1: 1.5.

In some embodiments, the magnetic composite material may further comprise one or more thermal conductive particles and/or a nanomagnetic material, the one or more thermal conductive particles and/or the nanomagnetic material may be adhered to the surface of each of at least a portion of the nano carbon crystal and at least a portion of a surface of the nano tungsten disulfide, and at least a portion of the interstices of the cluster of nano carbon crystals may be filled with the one or more thermal conductive particles and/or the nanomagnetic material.

In some embodiments, the nano graphene may be a porous graphene ellipsoid, the carbon nanomaterial cluster may be a graphene cluster comprising a plurality of porous graphene ellipsoids arranged in an orderly manner, and the nano metal sulfide may be a nano zinc sulfide.

In some embodiments, the plurality of porous graphene ellipsoids may be arranged in a three-dimensional array in the graphene cluster.

In some embodiments, one of the plurality of porous graphene ellipsoids may have an equatorial radius in a range of 100 nm-120 nm and a polar radius in a range of 200 nm-250 nm.

In some embodiments, one of the plurality of porous graphene ellipsoids may have a pore diameter in a range of 14 nm-25 nm.

In some embodiments, a ratio of a particle size of the nano zinc sulfide to a pore size of one of the plurality of porous graphene ellipsoids may be in a range of 1: 8-1: 12.

In some embodiments, a mass ratio of the nano zinc sulfide to the graphene cluster may be in a range of 1: 3-1: 5.

In some embodiments, the magnetic composite material may further comprise a functional nanomaterial, the functional nanomaterial being fused into the graphene cluster, wherein the functional nanomaterial may include a transition metal compound nanomaterial and/or a porous silicon carbide nanomaterial.

In some embodiments, the transition metal compound nanomaterial may include at least one of a hard magnetic ferrite nanomaterial, a silver nanomaterial, a ferrochromium cobalt alloy nanomaterial, a platinum cobalt alloy nanomaterial, or a ferronickel alloy nanomaterial.

In some embodiments, the transition metal compound nanomaterial may have a particle size in a range of 5 nm-15 nm, and a mass ratio of the transition metal compound nanomaterial to the graphene cluster may be in a range of 1: 3-1: 8.

In some embodiments, the magnetic composite material may further include an organic insulating material.

In some embodiments, a method of preparing a magnetic composite material may comprise: preparing a suspension of the nano tungsten disulfide and a suspension of the nano carbon crystal cluster, respectively; heating the suspension of the nano carbon crystal cluster to obtain a precipitate; and mixing the nano tungsten disulfide and the precipitate to obtain the magnetic composite material.

In some embodiments, the nano tungsten disulfide may be prepared according to operations including: reacting tungsten chloride with thioacetamide in a solution to obtain a solid product; wherein a mass percent of the tungsten chloride in the solution may be in a range of 0.4%-0.7%, a mass percent of the thioacetamide in the solution may be in a range of 0.9%-1.2%, a reaction temperature may be in a range of 270℃-290℃, and a reaction time may be in a range of 12 h-24 h; and sulfurizing the solid product to obtain the nano tungsten disulfide.

In some embodiments, the carbon nano crystal cluster may be prepared according to operations including: mixing a hydrogen peroxide solution with a dispersion of the first graphene oxide to obtain a solution of the second graphene oxide, wherein an oxidation degree of the second graphene oxide may be greater than an oxidation degree of the first graphene oxide; reacting and concentrating the solution of the second graphene oxide and a suspension of porous graphene oxide under a heating condition to obtain a concentrated product; and drying the concentrated product to obtain the nano carbon crystal cluster.

In some embodiments, a pore diameter of the porous graphene oxide may be 1.5-3 times a maximum diameter of the nano tungsten disulfide.

In some embodiments, a mass ratio of the second graphene oxide to the porous graphene oxide may be in a range of 1: 1-1: 3.

In some embodiments, a ratio of a mass percent of hydrogen peroxide in the hydrogen peroxide solution to a mass percent of the first graphene oxide in the dispersion of the first graphene oxide may be in a range of 1: 10-1: 35.

In some embodiments, the mixing the nano tungsten disulfide and the precipitate to obtain the magnetic composite material may comprise: preparing a suspension of the precipitate, mixing the suspension of the precipitate with the nano tungsten disulfide to obtain an initial magnetic composite material; and annealing the initial magnetic composite under a protective gas to obtain the magnetic composite material.

In some embodiments, a method of preparing a magnetic composite material may comprise preparing the graphene cluster based on a colloid crystal templating technique using poly (methyl vinyl acid ethyl ester) as a colloid crystal template under a first heating condition, wherein the first heating condition may comprise heating for 20 h-28 h at 180℃-220℃; mixing the graphene cluster with the nano zinc sulfide under a second heating condition to obtain the magnetic composite material.

One or more embodiments of the present disclosure may provide a wave-absorbing material made based on a magnetic composite material.

One or more embodiments of the present disclosure may provide an electronic device including a wave-absorbing material.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is further described in terms of exemplary embodiments. These exemplary embodiments are described in detail with reference to the drawings. These embodiments are non-limiting exemplary embodiments, in which like reference numerals represent similar structures throughout the several views of the drawings, and wherein:

FIG. 1 is a scanning electron micrograph illustrating a nano carbon crystal cluster made according to Embodiment 1 of the present disclosure;

FIG. 2 is a micrograph illustrating nano tungsten disulfide made according to Embodiment 1 viewed by a body-viewing microscope of the present disclosure;

FIG. 3 is a scanning electron micrograph illustrating nano tungsten disulfide made according to Embodiment 1 of the present disclosure;

FIG. 4 is a high magnification scanning electron micrograph illustrating nano tungsten disulfide made according to Embodiment 1 of the present disclosure;

FIG. 5 is a micrograph illustrating a magnetic composite material made according to Embodiment 1 viewed by a body-viewing microscope of the present disclosure;

FIG. 6 is a high magnification scanning electron micrograph illustrating a magnetic composite material made according to Embodiment 1 of the present disclosure;

FIG. 7 is a diagram illustrating an insertion loss of a magnetic composite material made according to Embodiment 1 of the present disclosure;

FIG. 8 is a physical diagram illustrating a compressed magnetic composite material made according to Embodiment 1 of the present disclosure after compression;

FIG. 9 is a micrograph illustrating a magnetic composite material made according to Embodiment 18 viewed by a body-viewing microscope of the present disclosure;

FIG. 10 is a diagram illustrating an insertion loss of a magnetic composite material made according to Embodiment 18 of the present disclosure;

FIG. 11 is a micrograph illustrating permalloy made in Embodiment 19 viewed by a body-viewing microscope of the present disclosure;

FIG. 12 is a micrograph illustrating a magnetic composite material made according to Embodiment 19 viewed by a body-viewing microscope of the present disclosure;

FIG. 13 is a diagram illustrating an insertion loss of a magnetic composite material made according to Embodiment 19 of the present disclosure;

FIG. 14 is a micrograph illustrating a magnetic composite material made according to Embodiment 30 viewed by a body-viewing microscope of the present disclosure;

FIG. 15 is a diagram illustrating an insertion loss of a magnetic composite material made according to Embodiment 30 of the present disclosure;

FIG. 16 is a micrograph illustrating a magnetic composite material made according to Embodiment 36 viewed by a body-viewing microscope of the present disclosure;

FIG. 17 is a diagram illustrating an insertion loss of a magnetic composite material made according to Embodiment 36 of the present disclosure;

FIG. 18 is a diagram illustrating a comparison between an insertion loss of a cured wave-absorbing gel made according to Embodiment 42 and an insertion loss of a cured wave-absorbing gel made according to Embodiment 5 of the present disclosure;

FIG. 19 is a radiometric far-field simulation diagram illustrating a printed circuit board according to Embodiment 48 of the present disclosure;

FIG. 20 is a radiometric far-field simulation diagram illustrating an electromagnetic shielding encapsulant according to Embodiment 48 of the present disclosure;

FIG. 21 is a radiometric far-field simulation illustrating a printed circuit board made according to Embodiment 55 of the present disclosure;

FIG. 22 is a radiometric far-field simulation illustrating a printed circuit board made according to comparative Embodiment 6 of the present disclosure;

FIG. 23 is a scanning electron micrograph illustrating a magnetic hollow tube made according to Embodiment 60 of the present disclosure, in which A represent carbon nanotubes, B represents a magnetic composite material, and C represents an adhesive;

FIG. 24 is a diagram illustrating an insertion loss of a magnetic hollow tube made according to Embodiment 60 of the present disclosure;

FIG. 25 is high magnification scanning electron micrograph illustrating a graphene cluster made according to some embodiments of the present disclosure; and

FIG. 26 is high magnification scanning electron micrograph a magnetic composite material made according to some embodiments of the present disclosure.

DETAILED DESCRIPTION

The technical solutions of the present disclosure embodiments will be more clearly described below, and the accompanying drawings need to be configured in the description of the embodiments will be briefly described below. Obviously, drawings described below are only some examples or embodiments of the present disclosure. Those skilled in the art, without further creative efforts, may apply the present disclosure to other similar scenarios according to these drawings. Unless obviously obtained from the context or the context illustrates otherwise, the same numeral in the drawings refers to the same structure or operation.

It should be understood that the "system" , "device" , "unit" , and/or "module" used herein are one method to distinguish different components, elements, parts, sections, or assemblies of different levels in ascending order. However, the terms may be displaced by other expressions if they may achieve the same purpose.

As shown in the present disclosure and claims, unless the context clearly prompts the exception, "a" , “an” , "one" , and/or "the" is not specifically singular form, and the plural form may be included. It will be further understood that the terms “comprise, ” “comprises, ” “comprising, ” “include, ” “includes, ” and/or “including, ” when used in the present disclosure, specify the presence of stated steps and elements, but do not preclude the presence or addition of one or more other steps and elements thereof.

The flowcharts are used in present disclosure to illustrate the operations performed by the system according to the embodiment of the present disclosure. It should be understood that the front or rear operation is not necessarily performed in order to accurately. Instead, the operations may be processed in reverse order or simultaneously. Moreover, one or more other operations may be added to the flowcharts. One or more operations may be removed from the flowcharts.

Embodiments of the present disclosure provide a magnetic composite material comprising a carbon nanomaterial cluster and nano metal sulfide. The carbon nanomaterial cluster may include a plurality of carbon nanomaterial units. The nano metal sulfide may be mixed with the carbon nanomaterial cluster.

The nano metal sulfide, due to its special electromagnetic property and structural features, may be designed to modulate a lattice structure and size, thereby absorbing electromagnetic waves in different frequency bands.

A plurality of reflections and scattering of electromagnetic waves may occur in the magnetic composite material caused by the nanoscale structure of metal sulfide, which increases an interaction between the electromagnetic waves and the magnetic composite material. The scattering effect in multiple interface may lead to a rapid dissipation of energy of the electromagnetic waves in the magnetic composite material, thereby achieving absorption. Meanwhile, the nano metal sulfide may typically have a high electrical conductivity, which allows the nano metal sulfide to effectively absorb the energy of the electromagnetic waves. When the electromagnetic waves pass through the magnetic composite material, electrons in the magnetic composite material may be excited and move, resulting in a transition and loss of electron energy levels, thereby converting the energy of the electromagnetic waves into thermal energy. On the other hand, a surface and an interface of the nano metal sulfide may produce an uneven distribution of electric charge, and the uneven distribution of electric charge may lead to polarization phenomenon of the electromagnetic waves in the magnetic composite material. The polarization phenomenon may cause an absorption and loss of the energy of the electromagnetic waves.

The dielectric property of the nano metal sulfide may change with frequency. In one or more certain frequency ranges, the dielectric loss of the magnetic composite material may increase, thereby promoting the energy loss and absorption of the electromagnetic waves in the magnetic composite material.

In some embodiments, the nano metal sulfide may include molybdenum sulfide, titanium sulfide, tungsten sulfide, zinc sulfide, etc.

In some embodiments, the nano metal sulfide may include nano tungsten disulfide and/or nano zinc sulfide. In some embodiments, one of the plurality of carbon nanomaterial units may include nano carbon crystal and/or nano graphene. In some embodiments, each carbon nanomaterial unit of the plurality of carbon nanomaterial units may include the nano carbon crystal. In some embodiments, each carbon nanomaterial unit of the plurality of carbon nanomaterial units may be the nano graphene.

In some embodiments, each carbon nanomaterial unit of the plurality of carbon nanomaterial units may include the nano carbon crystal, the carbon nanomaterial cluster may be a nano carbon crystal cluster including a plurality of the nano carbon crystals, and the nano metal sulfide may be the nano tungsten disulfide. The nano tungsten disulfide may be adhered to a surface of each of at least a portion of the plurality of the nano carbon crystals, and at least a portion of interstices of the nano carbon crystal cluster may be filled with the nano tungsten disulfide. An interstice among the interstices of the nano carbon crystal cluster may be between two nano carbon crystals in the nano carbon crystal cluster.

The nano tungsten disulfide may be not only adhered to the surfaces of at least a portion of the nano carbon crystals in the nano carbon crystal cluster, but also fill at least a portion of the interstices of the nano carbon crystal cluster, allowing for a closer and more stable bonding between nano carbon crystals and the nano tungsten disulfide. The nano carbon crystals and the nano tungsten disulfide in the magnetic composite material may have advantages of low density, light weight and good thermal stability.

In some embodiments, the nano tungsten disulfide may be in the form of three-dimensional structure. In some embodiments, the nano tungsten disulfide may be in the form of cubic shape.

In order to achieve a closer and more stable bonding between the nano carbon crystals and the nano tungsten disulfide, and to enhance the wave-absorbing performance within a specific absorption frequency band, the diameter of the nano tungsten disulfide needs to be reasonably designed. As used herein, a maximum projected surface of the nano tungsten disulfide may be designated as a tangent line to form a rectangle, then a long edge of the rectangle may be designated as the maximum diameter, and a short edge of the rectangle may be designated as the intermediate diameter. The maximum projected surface is a rectangle with a largest area among rectangles obtained by connecting the vertices of the cube.

In some embodiments, the nano tungsten disulfide may have a maximum diameter in a range of 3 nm-6 nm and an intermediate diameter in a range of 2 nm-5 nm.

In some embodiments the nano tungsten disulfide may have a maximum diameter in a range of 3 nm-5 nm. In some embodiments, the nano tungsten disulfide may have a maximum diameter in a range of 4 nm-5 nm. In some embodiments, the nano tungsten disulfide may have a maximum diameter in a range of 5 nm-6 nm.

In some embodiments, the nano tungsten disulfide may have a maximum diameter of 3 nm, or 3.5 nm, or 4 nm, or 4.5 nm, or 5 nm, or 5.5 nm, or 6 nm.

In some embodiments, the nano tungsten disulfide may have an intermediate diameter in a range of 2 nm-4 nm. In some embodiments, the nano tungsten disulfide may have an intermediate diameter in a range of 3 nm-4 nm. In some embodiments, the nano tungsten disulfide may have an intermediate diameter in a range of 4 nm-5 nm.

In some embodiments, the nano tungsten disulfide may have an intermediate diameter of 2 nm, or 2.5 nm, or 3 nm, or 3.5 nm, or 4 nm, or 4.5 nm, or 5 nm.

In some embodiments, the nano tungsten disulfide may have a maximum diameter of 5 nm and an intermediate diameter of 4 nm.

The effect of the maximum and intermediate diameters of the nano tungsten disulfide on the density, thermal conductivity, and wave-absorbing performance of the magnetic composite material may be seen in comparative results of Embodiments 7 to 11.

In some embodiments, one of the nano carbon crystals in the nano carbon crystal cluster may have a pore channel structure. The pore channels do not penetrate the nano carbon crystals, and the pore channels are distributed nonuniformly in the nano carbon crystals. In some embodiments, the nano carbon crystals may include one or more pore channel. When low-frequency or high-frequency electromagnetic waves are transmitted to the surface of the nano carbon crystals, the electromagnetic waves may undergo a plurality of reflections in the pore channel structure within the nano carbon crystals, resulting in a faster and more efficient conversion of the electromagnetic waves into heat energy, thus achieving a better absorption effect of the electromagnetic waves.

In some embodiments, one of the nano carbon crystals may be in the form of three-dimensional structure.

In some embodiments, one of the nano carbon crystals may be in the form of three-dimensional pyramid. In some embodiments, a ratio of the maximum diameter of the nano tungsten disulfide to an edge length of the nano carbon crystal may be in a range of 1: 1.8-1: 3.

The form of three-dimensional pyramid enables the nano carbon crystals to be tightly bonded with each other to form the nano carbon crystal cluster, and the edge length of the nano carbon crystal may affect the absorption frequency band and wave-absorbing performance of the magnetic composite material.

In some embodiments, the edge length of the nano carbon crystal may be in a range of 8 nm-13 nm.

In some embodiments, the edge length of the nano carbon crystal may be 8 in a range of nm-11.5 nm. In some embodiments, the edge length of the nano carbon crystal may be in a range of 10 nm-12 nm. In some embodiments, the edge length of the nano carbon crystal may be in a range of 11 nm-13 nm.

In some embodiments, the edge length of the nano carbon crystal may be 8 nm, or 10 nm, or 10.5 nm, or 11 nm, or 11.5 nm, or 12 nm, or 12.5 nm, or 13 nm, thereby providing a superior wave-absorbing performance for the magnetic composite material in a frequency band of 30 MHz-8 GHz.

In some embodiments, the ratio of the maximum diameter of the nano tungsten disulfide to the edge length of the nano carbon crystal may be in a range of 1: 1.8-1: 2. In some embodiments, the ratio of the maximum diameter of the nano tungsten disulfide to the edge length of the nano carbon crystal may be in a range of 1: 2-1: 3.

In some embodiments, the ratio of the maximum diameter of the nano tungsten disulfide to the edge length of the nano carbon crystal may be 1: 1.8, or 1: 2, 1: 2.5, or 1: 2.8, or 1: 3.

In some embodiments, the edge length of one of the carbon crystals may be 11.5 nm, and the ratio of the maximum diameter of the nano tungsten disulfide to the edge length of the nano carbon crystal may be 1: 2.3.

In some embodiments, the mass ratio of the nano tungsten disulfide to the nano carbon crystal cluster may be in a range of 1: 1.3-1: 1.5.

In some embodiments, the mass ratio of the nano tungsten disulfide to the nano carbon crystal cluster may be in a range of 1: 1.3-1: 1.4. In some embodiments, the mass ratio of the nano tungsten disulfide to the nano carbon crystal cluster may be in a range of 1: 1.4-1: 1.5.

In some embodiments, the mass ratio of the nano tungsten disulfide to the nano carbon crystal cluster may be 1: 1.3, or 1: 1.4, or 1: 1.5.

In some embodiments, the mass ratio of the nano tungsten disulfide to the nano carbon crystal cluster may be 1: 1.4.

In some embodiments of the present disclosure, the mass ratio of the nano tungsten disulfide to the nano carbon crystal cluster may be controlled to be in a range of 1: 1.3-1: 1.5, enabling better fusion between the nano carbon crystal cluster and the nano tungsten disulfide in the magnetic composite material, thereby providing a superior wave-absorbing performance for the magnetic composite material in a frequency band of 30MHz-8GHz. An effect of the mass ratio of the nano tungsten disulfide to the nano carbon crystal cluster on the magnetic composite material may be seen in comparative results of Embodiments 12 to 16.

The organic insulating material may include at least one of an adhesive insulating material layer or a non-adhesive insulating material layer. The adhesive insulating material layer may include alkenyl silicone oil, hydrogen silicone oil, etc. The non-adhesive insulating material layer may include boron nitride. For example, the magnetic composite material may include the adhesive insulating material layer and the non-adhesive insulating material layer. The adhesive insulating material layer may be located in a lower layer of the magnetic composite material, and the non-adhesive insulating material layer may be located in an upper layer of the magnetic composite material. The lower layer is adhered to the surface of the electronic component.

In some embodiments, the adhesive insulating material layer may include hydrocarbon-based silicone oil, water-soluble silicone oil, or the like. In some embodiments, the non-adhesive insulating material layer may include aluminum nitride, silicon nitride, or the like.

Embodiments of the present disclosure may provide a method for preparing a magnetic composite material. The method may include preparing a suspension of the nano tungsten disulfide and a suspension of the nano carbon crystal cluster, respectively; heating the suspension of the nano carbon crystal cluster to obtain a precipitate (e.g., a black precipitate) ; mixing the nano tungsten disulfide and the precipitate to obtain the magnetic composite material. The black precipitate may be an intermediate product produced after the reaction between the nano carbon crystal cluster and hydrochloric acid when the suspension of the nano carbon crystal cluster is heated.

In some embodiments, the suspension of the nano carbon crystal cluster may be prepared according to operations including dispersing the nano carbon crystal cluster in water to create an intermediate suspension with a concentration in a range of 0.8 g/L-1.2 g/L; and adding hydrochloric acid solution with a concentration in a range of 0.8 g/L-1.2 g/L to the intermediate suspension to obtain the suspension of the nano carbon crystal cluster.

In some embodiments, the concentration of the nano carbon crystal cluster in the intermediate suspension may range from 0.8 g/L to 1.0 g/L. In some embodiments, the concentration of the nano carbon crystal cluster in the intermediate suspension may range from 1.0 g/L to 1.1 g/L. In some embodiments, the concentration of the nano carbon crystal cluster in the intermediate suspension may range from 1.0 g/L to 1.2 g/L.

In some embodiments, the concentration of the nano carbon crystal cluster in the intermediate suspension may be 0.8 g/L, or 0.9 g/L, or 1.0 g/L, or 1.1 g/L, or 1.2 g/L.

In some embodiments, the concentration of the hydrochloric acid solution may be 0.8 g/L, or 0.9 g/L, or 1.0 g/L, or 1.1 g/L, or 1.2 g/L.

In some embodiments, heating the suspension of the nano carbon crystal cluster to obtain the precipitate may include placing the suspension of the nano carbon crystal cluster in a stainless steel reactor lined with tetrafluoroethylene, heating the suspension of the nano carbon crystal cluster to 250℃-280℃, and maintaining a reaction temperature for 20 h-30 h.

In some embodiments, the temperature for heating the suspension of the nano carbon crystal cluster may range from 250℃-265℃. In some embodiments, the temperature for heating the suspension of the nano carbon crystal cluster may range from 260℃ to 270℃. In some embodiments, the temperature for heating the suspension of the nano carbon crystal cluster may range from 260℃ to 280℃.

In some embodiments, the temperature for heating the suspension of the nano carbon crystal cluster may be 250℃, or 260℃, or 265℃, or 270℃, or 280℃.

In some embodiments, the suspension of the nano carbon crystal cluster is heated with a constant temperature for 20 h-24 h. In some embodiments, the suspension of the nano carbon crystal cluster is heated with a constant temperature for 24 h-26 h. In some embodiments, the suspension of the nano carbon crystal cluster is heated with a constant temperature for 24 h-30 h.

In some embodiments, the suspension of the nano carbon crystal cluster is heated with a constant temperature for 20 h, 22 h, 24 h, 26 h, or 30 h.

In some embodiments, the suspension of the nano carbon crystal cluster is heated with a constant temperature of 260℃ for 24 h.

In some embodiments, the nano tungsten disulfide may be prepared according to operations including reacting tungsten chloride with thioacetamide in a solution to obtain a solid product, and sulfurizing the solid product to obtain the nano tungsten disulfide. In some embodiments, in the reaction of tungsten chloride with thioacetamide in a solution, a mass percent of the tungsten chloride in the solution may be in a range of 0.4%-0.7%, a mass percent of the thioacetamide in the solution may be in a range of 0.9%-1.2%, a reaction temperature may be in a range of 270℃-290℃, and a reaction time may be in a range of 12 h-24 h.

In some embodiments, when the tungsten chloride is reacted with the thioacetamide in the solution, the mass percent of tungsten chloride in the solution may be in a range of 0.4%-0.5%. In some embodiments, when the tungsten chloride is reacted with the thioacetamide in the solution, the mass percent of the tungsten chloride in the solution may be in a range of 0.5%-0.6%. In some embodiments, when the tungsten chloride is reacted with the thioacetamide in the solution, the mass percent of the tungsten chloride in the solution may be in a range of 0.5%-0.7%.

In some embodiments, when the tungsten chloride is reacted with the thioacetamide in the solution, the mass percent of the tungsten chloride in the solution may be 0.4%, or 0.5%, or 0.55%, or 0.6%, or 0.7%.

In some embodiments, when the tungsten chloride is reacted with the thioacetamide in the solution, the mass percent of the thioacetamide in the solution may be in a range of 0.9%-1.0%. In some embodiments, when the tungsten chloride is reacted with the thioacetamide in the solution, the mass percent of the thioacetamide in the solution may be in a range of 1.0%-1.1%. In some embodiments, when the tungsten chloride is reacted with the thioacetamide in the solution, the mass percent of the thioacetamide in the solution may be in a range of 1.0%-1.2%.

In some embodiments, when the tungsten chloride is reacted with the thioacetamide in the solution, the mass percent of the thioacetamide in the solution may be 0.9%, or 1.0%, or 1.1%, or 1.2%.

In some embodiments, when the tungsten chloride is reacted with the thioacetamide in the solution, the reaction temperature may be in a range of 270℃ –280℃. In some embodiments, when the tungsten chloride is reacted with the thioacetamide in the solution, the reaction temperature may be in a range of 280℃-290℃.

In some embodiments, when the tungsten chloride is reacted with the thioacetamide in the solution, the reaction temperature may be 270℃, or 275℃, or 280℃, or 290℃.

In some embodiments, the reaction time of the tungsten chloride and thioacetamide in the solution may be in a range of 12 h-16 h. In some embodiments, the reaction time of the tungsten chloride and thioacetamide in the solution may be in a range of 12 h-18 h. In some embodiments, the reaction time of the tungsten chloride and thioacetamide in the solution may be in a range of 18 h-20 h. In some embodiments, the reaction time of the tungsten chloride and thioacetamide in the solution may be in a range of 18 h-24 h.

In some embodiments, the reaction time of the tungsten chloride and thioacetamide in the solution may be 12 h, or 16 h, or 18 h, or 20 h, or 24 h.

In some embodiments, the reaction temperature of the tungsten chloride and thioacetamide in the solution may be 280℃, and the reaction time may be 18 h.

The solid product may include unsulfurized tungsten sulfide, also be referred to as an intermediate product of tungsten sulfide. The intermediate product may include a mixture of chlorides and sulfides.

In some embodiments, after the solid product is obtained by reacting the tungsten chloride with the thioacetamide in the solution, the solid product may be sulfided to obtain the nano tungsten disulfide.

In some embodiments, the solid product may be dispersed in a sulfurization solvent for sulfurization. In some embodiments, the sulfurization solvent may include sodium thiopropane sulfonate (MPS) , dimethyl sulfur (DMS) , diethyl sulfur (DES) , etc. In some embodiments, the sulfurization solvent may a solvent mixture of MPS/dichloromethane with a volume ratio of 1: 15 and the solid product may be sulfurized using the solvent mixture of MPS/dichloromethane and refrigerated for one day at 4℃, and then the refrigerated product may be annealed under an argon atmosphere at 295℃ for 5 h. Finally, the nano tungsten disulfide may be produced.

In some embodiments, the solid product made from the reaction of the tungsten chloride with the thioacetamide may be sulfide, which can stabilize the nano tungsten disulfide and prevent the nano tungsten disulfide form being reduced during an operation of mixing with the carbon nano crystal cluster.

In some embodiments, the carbon nano crystal cluster may be prepared according to operations including mixing a hydrogen peroxide solution with a dispersion of a first graphene oxide to obtain a solution of a second graphene oxide. The oxidation degree of the second graphene oxide may be greater than the oxidation degree of the first graphene oxide. The operations may further include reacting and concentrating the solution of the second graphene oxide and a suspension of porous graphene oxide under a heating condition to obtain a concentrated product; and drying the concentrated product to obtain the nano carbon crystal cluster.

As used herein, the first graphene oxide refers to a graphene oxide with a lower oxidation degree. In some embodiments, the oxidation degree of the first graphene oxide is 20%-40%. In some embodiments, the oxidation degree of the first graphene oxide is 30%-40%. In some embodiments, the oxidation degree of the first graphene oxide is 30%. The second graphene oxide refers to a graphene oxide obtained by further oxidizing the first graphene oxide. In some embodiments, the oxidation degree of the second graphene oxide is 60%-80%. In some embodiments, the oxidation degree of the second graphene oxide may be 60%, 70%or 80%. The present disclosure may improve the oxidation degree of the first graphene oxide by mixing the first graphene oxide with the hydrogen peroxide solution to obtain the second graphene oxide with a higher oxidation degree, thereby enhancing the stability and heat dissipation effect of the graphene oxide.

In the operation of mixing the hydrogen peroxide with the first graphene oxide, the mass percent of the hydrogen peroxide in the hydrogen peroxide solution and the mass percent of the first graphene oxide in the dispersion of the graphene oxide may affect the edge length and the pore diameter of the nano carbon crystal. In some embodiments, the mass percent of the hydrogen peroxide in the hydrogen peroxide solution may be in a range of 1.5%-3%, e.g., 1.5%, 2.0%, 2.5%, 3%, etc; and the mass percent of the first graphene oxide in the dispersion of the first graphene oxide may be in a range of 40%-60%, e.g., 40%, 42.5%, 45%, 47.5%, 50%, 52.5%, 55%, 57.5%, 60%, etc., thereby resulting in the edge length of the nano carbon crystal ranging from 10 nm to 13 nm.

In some embodiments, a ratio of the mass percent of the hydrogen peroxide in the hydrogen peroxide solution to the mass percent of the first graphene oxide in the dispersion of the first graphene oxide may be in a range of 1: 10-1: 35.

In some embodiments, the ratio of the mass percent of the hydrogen peroxide in the hydrogen peroxide solution to the mass percent of the first graphene oxide in the dispersion of the first graphene oxide may be in a range of 1: 10-1: 30. In some embodiments, the ratio of the mass percent of the hydrogen peroxide in the hydrogen peroxide solution to the mass percent of the first graphene oxide in the dispersion of the first graphene oxide may be in a range of 1: 15-1: 30. In some embodiments, the ratio of the mass percent of the hydrogen peroxide in the hydrogen peroxide solution to the mass percent of the first graphene oxide in the dispersion of the first graphene oxide may be in a range of 1: 25-1: 30. In some embodiments, the ratio of the mass percent of the hydrogen peroxide in the hydrogen peroxide solution to the mass percent of the first graphene oxide in the dispersion of the first graphene oxide may be in a range of 1: 25-1: 35, e.g., 1: 25, 1: 26, 1: 27, 1: 28, 1: 29, 1: 30, 1: 31, 1: 32, 1: 33, 1: 34, 1: 35, etc., thereby resulting in the edge length of the nano carbon crystal ranging from 10 nm to 13 nm.

In some embodiments, the ratio of the mass percent of the hydrogen peroxide in the hydrogen peroxide solution to the mass percent of the first graphene oxide in the dispersion of the first graphene oxide may be 1: 10, 1: 11.7, 1: 15, or 1: 20. For the ratio of the mass percent of the hydrogen peroxide to the mass percent of the first graphene oxide, please refer to comparative results of Embodiments 2-6.

In some embodiments, the dispersion of the first graphene oxide may be prepared according to an operation including mixing hydrochloric acid with the first graphene oxide to obtain the dispersion of the first graphene oxide.

In some embodiments, reacting the second graphene oxide with the porous graphene oxide may include placing the second graphene oxide with the porous graphene oxide in a stainless steel reactor lined with polytetrafluoroethylene for heating to 250℃-280℃, and maintaining a constant reaction temperature for 10-15 h.

When a solution of the second graphene oxide is reacted with a suspension of the porous graphene oxide under a heating condition, the second graphene oxide and the porous graphene oxide may undergo chemical bond breakage and reorganization to form a plurality of nano carbon crystals in the form of three-dimensional prismatic with a pore channel structure.

In some embodiments, the reaction temperature of the second graphene oxide with the porous graphene oxide may be in a range of 120℃-130℃. In some embodiments, the reaction temperature of the second graphene oxide with the porous graphene oxide may be in a range of 130℃-140℃.

In some embodiments, the reaction temperature of the second graphene oxide with the porous graphene oxide may be 120℃, 125℃, 130℃, 135℃, or 140℃.

In some embodiments, after the second graphene oxide is heated with the porous graphene oxide to a temperature in a range of 120℃-140℃, the constant reaction temperature may be maintained for 10 h-13 h. In some embodiments, after the second graphene oxide is heated with the porous graphene oxide, the constant reaction temperature may be maintained for 11 h-13 h. In some embodiments, after the second graphene oxide is heated with the porous graphene oxide, the constant reaction temperature may be maintained for 13 h-14 h. In some embodiments, after the second graphene oxide is heated with the porous graphene oxide, the constant reaction temperature may be maintained for 13 h-15 h.

In some embodiments, after the second graphene oxide is heated with the porous graphene oxide, the constant reaction temperature may be maintained for 10 h, 11 h, 13 h, 14 h, or 15 h.

In some embodiments, the second graphene oxide and the porous graphene oxide may be placed in in the stainless steel reactor lined with polytetrafluoroethylene for heating to 130℃, and the constant reaction temperature of 130℃ may be maintained for 13 h.

In some embodiments, the mass ratio of the second graphene oxide to the porous graphene oxide may be in a range of 1: 1-1: 3.

In some embodiments, a mass ratio of the second graphene oxide to the porous graphene oxide may be in a range of 1: 1-1: 2. In some embodiments, the mass ratio of the second graphene oxide to the porous graphene oxide may be in a range of 1: 1-1: 2.5. In some embodiments, the mass ratio of the second graphene oxide to the porous graphene oxide may be in a range of 1: 1-1: 3.

In some embodiments, the mass ratio of the second graphene oxide to the porous graphene oxide may be 1: 1, 1: 2, 1: 2.5, or 1: 3.

In some embodiments, when the solution of the second graphene oxide and the suspension of the porous graphene oxide are concentrated under the heating condition, the temperature may be in a range of 100℃-150℃, e.g., 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, etc. Manners of drying the concentrated product may include, but not limited to, drying under a vacuum condition.

In some embodiments, the pore diameter of the porous graphene oxide may be 1.5-3 times the maximum diameter of the nano tungsten disulfide.

In some embodiments, the pore diameter of the porous graphene oxide may be 1.5-2 times the maximum diameter of the nano tungsten disulfide. In some embodiments, the pore diameter of the porous graphene oxide may be 2-3 times the maximum diameter of the nano tungsten disulfide. In some embodiments, the pore diameter of the porous graphene oxide may be 2.5-3 times the maximum diameter of the nano tungsten disulfide.

In some embodiments, the pore diameter of the porous graphene oxide may be 1.5, 2, 2.5, or 3 times the maximum diameter of the nano tungsten disulfide.

In some embodiments, the mixing the nano tungsten disulfide and the precipitate to obtain the magnetic composite material may include preparing a suspension of the precipitate which is obtained by heating the suspension of the nano carbon crystal cluster; mixing the suspension of the precipitate with the nano tungsten disulfide to obtain an initial magnetic composite material; and annealing the initial magnetic composite under a protective gas to obtain the magnetic composite material.

In some embodiments, the suspension of the precipitate may be prepared according to operations including mixing the precipitate with a mixed solution of MPS/dichloromethane to generated a mixed product, and sulfurizing the mixed product at 3℃-5℃ for 20-72 h to obtain the suspension of the precipitate. The sulfurizing the suspension of the precipitate including the nano carbon crystal cluster can avoid the reduction of the nano tungsten disulfide by the nano carbon crystals, so that the nano tungsten disulfide can be stably adhered to the surface of at least a portion of the carbon crystals or fill at least a portion of the interstices of the nano carbon crystal cluster.

The embodiments of the present disclosure do not impose any special limitation on the operation of mixing the nano tungsten disulfide with the precipitate, and any mixing manner may realize that the nano tungsten disulfide is adhered to the surface of each of at least a portion of of the nano carbon crystals, and at least a portion of the interstices of the nano carbon crystal cluster is filled with the nano tungsten disulfide.

In some embodiments, when the initial magnetic composite material is annealed under the protective gas, an annealing temperature may be in a range of 290℃-310℃, e.g., 290℃, 295℃, 300℃, 305℃, 310℃, etc., an annealing time may be in a range of 4 h-6 h, e.g., 4 h, 4.5 h, 5 h, 5.5 h, 6 h, etc., and the protective gas may be at least one of an inert gas or nitrogen.

In some embodiments, when the initial magnetic composite material may be annealed under the protective gas, the annealing temperature may be 300℃, the annealing time may be 5 h, and the protective gas may be selected from at least one of an inert gas or nitrogen.

In some embodiments, the magnetic composite material may further include one or more thermal conductive particles and/or a nanomagnetic material, the one or more thermal conductive particles and/or the nanomagnetic material may be adhered to the surface of at least a portion of the nano carbon crystals and at least a portion of a surface of the nano tungsten disulfide, and at least a portion of the interstices of the cluster of nano carbon crystals may be filled with the one or more thermal conductive particles and/or the nanomagnetic material, which further improves the wave-absorbing performance of the magnetic composite material in specific frequency bands.

The nanomagnetic material refers to a magnetic material with a nanoscale dimension (e.g., 1 nm to 100 nm) .

In some embodiments, the nanomagnetic material may include at least one of a zero-dimensional nanomagnetic material, a one-dimensional nanomagnetic material, a two-dimensional nanomagnetic material, or a three-dimensional nanomagnetic material. The zero-dimensional nanomagnetic material typically refers to particles or powders with a nanoscale dimension, such as nanoparticles, nanocrystals, or the like. The one-dimensional nanomagnetic material may include a material with a nanoscale length, a larger width, and a larger thickness, such as nanowire (s) , nanorod (s) , e.g., which may lead to an enhanced or altered magnetic behavior in the one-dimensional direction. The two-dimensional nanomagnetic material typically refers to a material with a nanoscale dimension in a two-dimensional plane, such as a nanosheet, a two-dimensional magnetic nanolayer, etc., which may exhibit different magnetic behaviors due to a scale effect within the plane and an influence of a lattice structure. The three-dimensional nanomagnetic material refers to a material with a nanoscale dimension in each of all three dimensions. The three-dimensional nanomagnetic material may be usually an aggregation of tiny particles or structures, e.g., polycrystalline or multiphase. In some embodiments, the zero-dimensional nanomagnetic material may include at least one of copper powder or iron powder. In some embodiments, the one-dimensional nanomagnetic material may include at least one of a ferroferric oxide, permalloy, or carbon nanotube (s) . In some embodiments, the two-dimensional nanomagnetic material may include at least one of carbonyl iron, metal sulfide, or anisotropic graphene. In some embodiments, the three-dimensional nanomagnetic material may include at least one of MoS₂ or a transition metal oxide.

In some embodiments, when the magnetic composite material further includes the thermal conductive particles and/or the magnetic nanomaterial, after the suspension of the precipitate is mixed with the nano tungsten disulfide, and the suspension of the precipitate may further be mixed with the thermal conductive particles and/or the magnetic nanomaterial to obtain the magnetic composite material.

When the nanomagnetic material include a one-dimensional nanomagnetic material, the embodiments of the present disclosure do not impose any special restrictions on the source of the one-dimensional nanomagnetic material, which may be prepared independently or obtained directly from a commercially available source. The embodiments of the present disclosure do not impose any special limitations on the operation of mixing the mixed product with the one-dimensional nanomagnetic material.

In some embodiments, the one-dimensional nanomagnetic material may be ferroferric oxide. The ferroferric oxide may be prepared by chemical precipitation. For example, the ferroferric oxide may be obtained by adding an alkaline reagent to a solution containing Fe²⁺ and Fe³⁺ for a precipitation reaction. As another example, an alkaline reagent may be added to a solution containing only Fe²⁺ for a precipitation reaction to obtain Fe (OH) ₂, and then an oxidizing agent may be added to partially oxidize Fe (OH) ₂. Alternatively, a precipitation reaction may be performed by adding an alkaline reagent to a solution containing only Fe³⁺ to obtain Fe (OH) ₃, and then adding a reducing agent to partially reduce Fe (OH) ₃.

In some embodiments, the mixed product of the suspension of the precipitate mixed and the nano tungsten disulfide (which can also be referred to as mixed product) may be further mixed with the one-dimensional magnetic nanomaterial according to operations including mixing the mixed product of the suspension of the precipitate and the nano tungsten disulfide with ferroferric oxide and then grinding to obtain a grinding product; mixing the grinding product with a compound containing NH₃ ⁺ and stirring to obtain a stirred product, and then lyophilizing the stirred product in a protective gas atmosphere to obtain the magnetic composite material.

In embodiments of the present disclosure, the compound containing NH₃ ⁺ may be capable of balancing an ionic count of Fe²⁺ in the one-dimensional nanomagnetic material and controlling a ratio of Fe²⁺ to Fe³⁺. In some embodiments, the ratio of Fe²⁺ to Fe³⁺ of the one-dimensional nanomagnetic material may be 1: 2.

In some embodiments, the mass ratio of the grinding product to the NH₃ ⁺-containing compound may be in a range of 2: 1-1.5: 1, e.g., 2: 1, 1.9: 1, 1.8: 1, 1.7: 1, 1.6: 1, 1.5: 1, etc.

In some embodiments, the grinding product may be mixed with the compound containing NH₃ ⁺ and stirred at a temperature in a range of -1℃-3℃, e.g., -1℃, 0℃, 1℃, 2℃, 3℃, etc.

In some embodiments, the one-dimensional nanomagnetic material may include permalloy. The permalloy may be prepared by pyrolytic annealing according to operations including dissolving a Fe³⁺-containing salt, a Ni²⁺-containing salt, and glucose in water to obtain a mixed solution, drying the mixed solution to remove a solvent and obtain a solid product, and conducting a pyrolysis reaction on the solid product to obtain a pyrolysis product, annealing the pyrolysis product under a protective gas, acid washing and purifying the pyrolysis product to obtain a pre-product, adding a lubricant to the pre-product and grinding the pre-product to obtain the permalloy. The lubricant may include an oil-based liquid lubricant.

In embodiments of the present disclosure, adding the glucose enables a more homogeneous mixing of the pyrolysis product with the lubricant.

In some embodiments, the mixing the mixed product made by mixing the suspension of the precipitate with the nano tungsten disulfide with the one-dimensional magnetic nanomaterial may include mixing the mixed product with the permalloy, heating and fusing to obtain a molten product, and then cooling the molten product in a protective gas to obtain the magnetic composite material.

In some embodiments, the heating and fusing may be performed at a temperature ranging from 40℃ to120℃, e.g., 40℃, 50℃, 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, 120℃, etc.

In some embodiments, the heating and fusing may be performed at a temperature of 100℃for 12 h.

In some embodiments, the nanomagnetic material may include a two-dimensional nanomagnetic material. The embodiments of the present disclosure do not have any specific limitations on the source of the two-dimensional nanomagnetic materials, and the two-dimensional nanomagnetic material may be prepared independently or obtained directly from a commercially available source.

In some embodiments, the two-dimensional nanomagnetic material may include two-dimensional iron nanocarbonyl. The two-dimensional iron nanocarbonyl may be obtained by thermally decomposing iron pentacarbonyl according to operations including thermally decomposing the iron pentacarbonyl to obtain a decomposed product, then reducing the decomposed product with hydrogen to obtain a soft powder, and finally grinding the soft powder to obtain the two-dimensional iron nanocarbonyl. In the embodiments of the present disclosure, grinding the soft powder can change shape anisotropy and a particle size of the two-dimensional iron nanocarbonyl, thereby making the two-dimensional iron nanocarbonyl more delicate and better mixed with the mixed product.

In some embodiments, a particle size of the soft powder may be in a range of 80 nm-120 nm. In some embodiments, a grinding pressure when grinding the soft powder may be 0.2 in a range of MPa-1.0 MPa, e.g., 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa, 1.0 MPa, etc. A rotation speed of the grinding may be in a range of 100 rpm-400 rpm, e.g., 100 rpm, 150 rpm, 200 rpm, 210 rpm, 220 rpm, 230 rpm, 240 rpm, 250 rpm, 260 rpm, 270 rpm, 280 rpm, 290 rpm, 300 rpm, 350 rpm, 400 rpm, etc. A grinding time may be in a range of 10 h-24 h, e.g., 10 h, 11 h, 12 h, 13 h, 14 h, 15 h, 16 h, 17 h, 18 h, 19 h, 20 h, 21 h, 22 h, 23 h, 24 h, etc. By implementing the above parameters, a maximum diameter of the two-dimensional iron nanocarbonyl may be achieved within a range of 3 nm-5 nm, an intermediate diameter of the two-dimensional iron nanocarbonyl may range from 2 nm to 4 nm, and a hardness of the two-dimensional iron nanocarbonyl may be in a range of 100 N/mm²-130 N/mm².

In some embodiments, for obtaining the two-dimensional iron nanocarbonyl, the grinding pressure may be 0.7 MPa, the rotation speed of the grinding may be 150 rpm, and the grinding time may be 12 h.

The iron pentacarbonyl may be obtained by reacting CO with iron under a high temperature and pressure. To prevent a disproportionation reaction of CO, NH₃ may be usedas a protective gas.

In some embodiments, the mixing the mixed product with the two-dimensional iron nanocarbonyl may include adding the mixed product and the two-dimensional iron nanocarbonyl to a reducing solution, heating and stirring the reducing solution including the mixed product and the two-dimensional iron nanocarbonyl, and then cooling the heated reducing solution in a reducing gas atmosphere to obtain the magnetic composite material. The reducing solution and the reducing gas may be capable of avoiding oxidation of the two-dimensional iron nanocarbonyls. In some embodiments, the reducing solution may include a ferrous chloride solution, and the reducing gas may include at least one of hydrogen or CO.

In some embodiments, a temperature of the heating and stirring stirring the reducing solution including the mixed product and the two-dimensional iron nanocarbony may be in a range of 40℃-60℃, e.g., 40℃, 45℃, 50℃, 55℃, 60℃, etc.

In some embodiments, the temperature of the heating and stirring stirring the reducing solution including the mixed product and the two-dimensional iron nanocarbony may be 50℃ and a time of the heating and stirring may be 6h.

In some embodiments, the nanomagnetic material may include a zero-dimensional nanomagnetic material. The embodiments of the present disclosure do not impose any special restrictions on the source of the zero-dimensional nanomagnetic materials, which may be prepared independently or obtained directly from a commercially available source.

In some embodiments, the zero-dimensional nanomagnetic material may include copper powder. The manner of preparing copper powder mainly may include a physical preparation manner or a chemical preparation manner. The physical preparation manner mayinclude using a radiation synthesis technique, a mechanical ball grinding technique, a plasma technique, an inert gas condensation technique, an ion sputtering technique, adeep plastic deformation technique, or the like, or a combination thereof. The chemical preparation manner may include using a chemical reduction technique, a uniform precipitation technique, an electrochemical technique, a sol-gel technique, organic liquid phase synthesis technique, or the like, or a combination thereof.

In some embodiments, the copper powder may be prepared by using a chemical reduction technique including dissolving a copper salt, reducing agent, dispersing agent, and antioxidant in a solvent to obtain a mixed solution, performing a reduction reaction on the mixed solution, and obtaining the copper powder after post-processing.

In some embodiments, the copper salt may include at least one of anhydrous copper chloride or copper sulfate pentahydrate, the reducing agent may include at least one of sodium phosphite or sodium borohydride, the dispersing agent may include at least one of polyvinylpyrrolidone or octadecylamine, and the antioxidant may include at least one of isopropanol or octadecanethiol.

The lengths of the copper powder in the X, Y, and Z directions may be affected by at least one of concentrations of the copper salt and the dispersing agent in the mixed solution, the mass ratio of the reducing agent to the copper salt, the mass ratio of the antioxidant to the copper salt, and the temperature and the time of the reduction reaction. In some embodiments, in the mixed solution, a molar concentration of the copper salt may be in a range of 0.1 mol/L-8 mol/L, e.g., 0.1 mol/L, 1 mol/L, 2 mol/L, 3 mol/L, 4 mol/L, 5 mol/L, 6 mol/L, 7 mol/L, 8 mol/L, etc. A mass-to-volume ratio of the dispersing agent may be in a range of 10 g/L-60 g/L, e.g., 10 g/L, 20 g/L, 30 g/L, 40 g/L, 50 g/L, 60 g/L, etc. A molar ratio of the reducing agent to the copper salt may be in a range of 0.4: 1-3.5: 1, e.g., 0.4: 1, 0.5: 1, 1.0: 1, 1.5: 1, 2.0: 1, 2.5: 1, 3.0: 1, 3.5: 1, etc. A molar ratio of the antioxidant to the copper salt may be in a range of 0.1: 1.5-3: 1, e.g., 0.1: 1.5, 1.5: 1.25, 3: 1, etc. The temperature of the reduction reaction may be in a range of 150℃-200℃, e.g., 150℃, 160℃, 170℃, 180℃, 190℃, 200℃, etc. The time of the reduction reaction may be in a range of 60 min-180 min, e.g., 60 min, 80 min, 100 min, 120 min, 140 min, 160 min, 180 min, etc. According to above data, the copper powder may have the length of 1 nm to 4 nm in each of the X, Y, and Z directions.

In some embodiments, the length of the copper powder may be 3 nm in each of the X, Y, and Z axis directions.

In some embodiments, the mixing the mixed product with the copper powder may include mixing the mixed product with the copper powder in a reducing gas atmosphere to obtain an intermediate mixed product, and heating and fusing of the intermediate mixed product by using a thermal reduction technique to obtain a heated reduction product, and then cooling the heated reduction product in an inert gas atmosphere to obtain the magnetic composite material. The heating and fusing of the intermediate mixed product may be performed at a temperature in a range of 40℃-60℃, e.g., 40℃, 45℃, 50℃, 55℃, 60℃, etc.

In some embodiments, the temperature of the heating and fusing of the intermediate mixed product may be 50℃.

In some embodiments, the reducing gas may be selected from hydrogen or CO.

The method of preparing a magnetic composite material provided in the present disclosure has a simple preparation process, and the prepared magnetic composite material may be lightweight, thermally stable, and have a wide absorption bandwidth and strong wave absorption performance.

Embodiments of the present disclosure may also provide a wave-absorbing composition. In some embodiments, the wave-absorbing composition may include a magnetic composite material consisting of tungsten sulfide and a nano carbon crystal cluster. In some embodiments, the wave-absorbing composition may include a magnetic composite material consisting of nano zinc sulfide and a nano graphene cluster.

The wave-absorbing composition provided in embodiments of the present disclosure may be in the form of a gel. In some embodiments, the wave-absorbing composition may include a magnetic composite material and an adhesive. In some embodiments, the wave-absorbing composition may include a magnetic composite material, a resin, and a solvent. In some embodiments, the wave-absorbing composition may include a magnetic composite material, one or more carbon nanotubes, and an adhesive.

In some embodiments, when the wave-absorbing composition is in the form of a gel, the wave-absorbing gel may include a body and the magnetic composite material dispersed in the body. It should be noted that the wave-absorbing gel including the above-described magnetic composite material may have excellent wave-absorbing performance. The wave-absorbing gel may have an absorption bandwidth that covers an electromagnetic wave in a frequency band of 30 MHz to 3.5 GHz, with an insertion loss of 14 dB or more.

In some embodiments, the mass percent of the magnetic composite material in the wave-absorbing gel may be in a range of 65%-75%, e.g., 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, etc.

In some embodiments, the mass percent of the magnetic composite material in the wave-absorbing gel may be 70%.

In order to better convert the electromagnetic waves absorbed by the wave-absorbing gel into latent heat, the absorbing gel may further include metal-based powder dispersed in the body, the metal-based powder may be adhered the surface of at least a portion of the nano carbon crystals and at least a portion of the surface of the nano tungsten disulfide. In some embodiments, a magnetic permeability of the metal-based powder may be greater than or equal to 3.5 H/m. The metal-based powder may include at least one of iron powder, copper powder, aluminum powder, magnesium powder, or their oxides. In some embodiments, the body may be obtained by cross-linking vinyl silicone oil with hydrogen-containing silicone oil.

In some embodiments, the mass percent of the metal-based powder in the absorbing gel may be in a range of 2%-10%, e.g., 2%, 2.5%, 3.0%, 3.5%, 4%, 4.5%, 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5%, 8%, 8.5%, 9.0%, 9.5%, 10%, etc.

The present disclosure may provide an absorbing gel with high compression modulus, electrical insulation, wide absorption bandwidth, strong absorbing performance, and good thermal conductivity, which can be well applied to prepare absorbing materials such as shielding covers.

Embodiments of the present disclosure may provide a method of preparing a wave-absorbing gel including mixing the magnetic composite material with a raw material for preparing the body, and preparing, by a single-component gel preparation manner or a two-component gel preparation manner, the wave-absorbing gel.

Taking an example that the body is obtained by cross-linking the vinyl silicone oil with the hydrogen-containing silicone oil, the single-component gel preparation manner may include following operations.

In S301, a first mixture may be obtained by mixing the vinyl silicone oil with an inhibitor.

In S302, a second mixture may be obtained by adding the magnetic composite material into the first mixture.

In S303, a third mixture may be obtained by adding the hydrogen-containing silicone oil into the second mixture; and a catalyst may be added to the third mixture to perform a cross-linking reaction to obtain a wave-absorbing gel.

In S301, in order to optimize the adhesion of the wave-absorbing gel, the viscosity of the vinyl silicone oil may be in a range of 30 mm²/s-100 mm²/s, and the vinyl content in the vinyl silicone oil may be in a range of 0.1%-3.0%.

For example, the viscosity of the vinyl silicone oil may be 80 mm²/s, and the vinyl content in the vinyl silicone oil may be 0.2%. In some embodiments, the inhibitor may include at least one of ethynylcyclohexanol, 2-phenyl-3-butyn-2-ol, 2-methyl-3-butynyl-2-ol, 3-methyl-1-ethynyl-3-ol, 3, 5-dimethyl-1-ethynyl-3-ol, or 3-methyl-1-dodecynyl-3-ol.

In some embodiments, the mass ratio of the vinyl silicone oil to the inhibitor may be in a range of 7: 1-10: 1. For example, the mass ratio of the vinyl silicone oil to the inhibitor may be 8: 1.

In some embodiments, the mixing the vinyl silicone oil with the inhibitor may include adding the vinyl silicone oil and the inhibitor to a double star blender for further mixing. For a more homogeneous mixing, the vinyl silicone oil and the inhibitor may be mixed under a vacuum in a range of 80 kPa-90 kPa at a temperature in a range of 30℃-150℃ and with a mixing rotation speed in a range of 50 rpm-100 rpm.

In some embodiments, the mixture of the vinyl silicone oil and the inhibitor may be further heated at 50℃-60℃ and then cooled to obtain the first mixture.

In S302, the mass ratio of the magnetic composite material to the vinyl silicone oil may be in a range of 3: 1-5: 1.

For example, the mass ratio of the magnetic composite material to the vinyl silicone oil may be 4: 1.

For a more homogeneous mixing, after the magnetic composite material is added to the first mixture, the first mixture and the magnetic composite material may be heated at 300℃-400℃, and then cooled to obtain the second mixture.

When the wave-absorbing gel includes a metal-based powder, operation S302 may further include adding the metal-based powder to the first mixture, so that the second mixture may include the metal-based powder.

In S303, in order to optimize the adhesion of the wave-absorbing gel, the viscosity of the hydrogen-containing silicone oil may be in a range of 5 mm²/S-500 mm²/S, and the hydrogen content may be in a range of 0.01%-1.2%. In some embodiments, the mass ratio of the hydrogen-containing silicone oil to the vinyl silicone oil may be in a range of 1: 1-2: 1.

For example, the viscosity of the hydrogen-containing silicone oil may be 200 mm²/S, and the hydrogen content may be 0.08%. For example, the mass ratio of the hydrogen-containing silicone oil to the vinyl silicone oil may be 1.5: 1.

For a more homogeneous mixing, the hydrogen-containing silicone oil may be added to the second mixture, and the second mixture and the hydrogen-containing silicone oil may be further heated at 300℃-400℃, and then cooled, to obtain the third mixture.

In S304, in order to optimize the adhesion of the wave-absorbing gel, a mass ratio of the catalyst to the vinyl silicone oil may be in a range of 0.01: 1-0.1: 1.

For example, the mass ratio of the catalyst to the vinyl silicone oil may be 0.05: 1.

In some embodiments, the catalyst may include at least one of chloroplatinic acid, chloroplatinic acid-isopropanol complex, or chloroplatinic acid-divinyltetramethyl disiloxane complex.

In some embodiments, after the catalyst is added to the third mixture, the catalyst and the third mixture may be further heated at 80℃-120℃ and then cooled to obtain the wave-absorbing gel.

The two-component gel preparation manner may include following operations.

In S305, the vinyl silicone oil may be mixed with the inhibitor, and then the mixed vinyl silicone oil and the inhibitor may be added to the magnetic composite material to obtain component A.

In S306, the vinyl silicone oil may be mixed with the hydrogen-containing silicone oil and catalyst, and then the mixed vinyl silicone oil, the hydrogen-containing silicone oil, and the catalyst may be added to the magnetic composite material to obtain component B.

In S307, the component A may be mixed with the component B for a cross-linking reaction to obtain the wave-absorbing gel.

When using the two-component gel preparation manner, mass ratios of any two of the vinyl silicone oil, the hydrogen-containing silicone oil, the magnetic composite material, the inhibitor, and the catalyst may be directly referenced from the mass ratios of the single-component gel preparation manner. The selection of types of the vinyl silicone oil, the hydrogen-containing silicone oil, the inhibitor, and the catalyst may also be directly referenced from types thereof in the single-component gel preparation manner.

In order to optimize the adhesion of the wave-absorbing gel, the vinyl silicone oil used in S305 may account for 10%-20%of a total amount of the vinyl silicone oil used in S305 and S306 during mixing the vinyl silicone oil with the inhibitor.

In order to achieve more excellent wave-absorbing performance within the frequency band of 30 MHz-3.5 GHz, the magnetic composite material added in S305 may account for 65%-75%of a total amount of the magnetic composite material in S305 and S306.

When the wave-absorbing gel includes metal-based powder, the metal-based powder may be added to the component A. In order to enhance heat dissipation performance, the metal-based powder used in S305 may account for 1%-5%of a total amount of metal-based powder used in S305 and S306.

In order to optimize the adhesion of the wave-absorbing gel, the vinyl silicone oil used in S306 may account for 80%-90%of the total amount of the vinyl silicone oil used in S305 and S306 during mixing and stirring the vinyl silicone oil with the hydrogen-containing silicone oil and the catalyst.

In order to achieve the more excellent wave-absorbing performance within the frequency band of 30 MHz-3.5 GHz, the magnetic composite material added in S306 may account for 25%-35%of the total amount of the magnetic composite material in S305 and S306.

When the wave-absorbing gel also includes metal-based powder, the metal-based powder may be added to the component B. In order to enhance the heat dissipation performance, the metal-based powder used in S306 may account for 95%-99%of the total amount of metal-based powder used in S305 and S306.

In S307, when the component A is mixed with the component B, the mass ratio of the component A to the component B may be in a range of 1: 1-1: 2.

In order to make the cross-linking reaction proceed more fully, the cross-linking reaction may be performed at a temperature in a range of 90℃-110℃ and for a time in a range of 0.3 h-0.7 h.

Embodiments of the present disclosure may also provide a manner of applying the wave-absorbing gel (as described above) for preparing an electronic device. The manner may include: dispensing the wave-absorbing gel at one or more predetermined locations in the electronic device, and then performing a molding.

In some embodiments, the wave-absorbing gel may be dispensed at the predetermined locations using a dispensing nozzle of a dispensing machine.

The wave-absorbing gel provided by the embodiments of the present disclosure may have a high compression modulus. Therefore, the wave-absorbing gel may have the following advantages: first, in addition to forming electronic components in different sizes and different forms directly through the dispensing machine and other device, it can not only eliminate electromagnetic interference, isolate signal crosstalk, and reduce spatial coupling, but also achieve a fixed-point quantitative control and automated production, saving labor while also improving production efficiency; second, it can automatically fill interstices and adhere well to an exterior surface of the electronic device or the electronic components therein, making the interface compatible, which not only applies to a variety of complex and subtle surface structures, but also maximizes a contact area; third, the wave-absorbing gel also has advantages of electrical insulation, wide absorption bandwidth, and strong wave-absorbing performance, which can effectively reduce an electromagnetic leakage and minimize a risk of short circuits; fourth, it effectively avoids structural interference; and fifth, it can be applicable to thin, high-density, or fine electronic devices.

When the wave-absorbing composition includes the magnetic composite material and an adhesive, in some embodiments, the wave-absorbing composition may be used in the preparation of an electronic device, such as an e electromagnetic shielding encapsulant. Specifically, the electromagnetic shielding encapsulant may include a printed circuit board, an insulating layer stacked on an outer surface of the printed circuit board, and a wave-absorbing material. The wave-absorbing material may be prepared from the wave-absorbing composition.

In some embodiments, the wave-absorbing composition may further include an insulating substance.

At this time, the wave-absorbing composition may be obtained by mixing the magnetic composite material with the adhesive.

In order to fully mix the magnetic composite material with the adhesive, the magnetic composite material may be mixed with the adhesive at a temperature of 50℃ to 60℃, which includes but is not limited to 50℃, 52℃, 54℃, 56℃, 58℃, or 60℃.

When the wave-absorbing composition also includes the insulating substance, the insulating substance may be simply added to the wave-absorbing composition.

When the wave-absorbing composition includes the magnetic composite material, resin, and solvent, the wave-absorbing composition may be used to prepare an electronic device such as a printed circuit board. The printed circuit board may include a dielectric layer and a conductive layer stacked on at least one surface of the dielectric layer. The dielectric layer may be prepared from the wave-absorbing composition and may contain the magnetic composite material.

The present disclosure does not limit the type of resin and allows for adjustment of the resin according to application scenarios. In some embodiments, the resin may be epoxy resin, e.g., bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenolic modified epoxy resin, isocyanate epoxy resin, biphenyl type epoxy resin, phosphated epoxy resin, glycidyl ester type epoxy resin, brominated epoxy resin, etc.

In some embodiments, the epoxy resin may have an epoxy equivalent in a range of 400 g/eq-500 g/eq, a bromine content in a range of 15%-22%, a hydrolyzed chlorine content less than or equal to 0.04%, and adhesion in a range of 2000 MPa·s-3000 MPa·s.

The amount of the magnetic composite material affects the wave-absorbing and shielding performance of the dielectric layer of the printed circuit board. Furthermore, to ensure better integration and molding of the printed circuit board, a mass of the magnetic composite material may be in a range of 20-50 parts by weight based on 100 parts by weight of resin. For example, the mass may be 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, or 50 parts by weight, thereby enhancing the wave absorbing and shielding performance of the dielectric layer.

In some embodiments, an adjuvant may be also added when the magnetic composite material is mixed with the resin and the solvent.

In some embodiments, the adjuvant may include at least one of a curing agent, a thermal conductive agent, or an accelerator.

When the adjuvant includes a curing agent, optionally, the curing agent may include at least one of a dicyandiamide curing agent, an aromatic amine curing agent, an aliphatic amine curing agent, or a polyamide curing agent. According to 100 parts by weight of the resin, a mass of the curing agent may be less than or equal to 20 parts by weight.

It should be noted that when the resin in the resin composition is selected from self-curing resin, the curing agent may not be included in the adjuvant, and the self-curing resin may be capable of cross-linking and curing on its own under a certain condition of pressure and temperature.

When the adjuvant includes an accelerator, the accelerator may catalyze a free radical reaction. Optionally, the accelerator may include at least one of 1, 1, 2, 2-Tetrahydroxyphenylethane tetraglycidyl ether, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, or 2-phenylimidazole. According to 100 parts by weight of the resin, a mass of the accelerator may be less than or equal to 10 parts by weight.

When the adjuvant includes a thermal conductive agent, the thermal conductive agent may further enhance the heat dissipation performance of the dielectric layer. Optionally, the thermal conductive agent may include at least one of boron nitride, aluminum nitride, silicon nitride, magnesium oxide, alumina, or silicon dioxide. According to 100 parts by weight of the resin, a mass of the thermal conductive agent may be less than or equal to 10 parts by weight.

In some embodiments, the solvent may include at least one of dimethylformamide, ethyl acetate, or isopropyl alcohol.

When the wave-absorbing composition includes the magnetic composite material, carbon nanotube (s) , and an adhesive, the carbon nanotube (s) , serving as a one-dimensional macroscopic assembly material, may be uniformly arranged in the horizontal direction. The carbon nanotube (s) may cooperate with the magnetic composite material in the embodiments of the present disclosure to further improve the wave-absorbing performance of the wave-absorbing composition in a specific frequency band. In this case, the wave-absorbing composition may be used to prepare a wave-absorbing material, such as a magnetic hollow tube.

In some embodiments, a manner of preparing the wave-absorbing composition may include following operations.

In S40, carbon nanotubes and an adhesive may be provided; and

In S50, the magnetic composite material may be mixed with the carbon nanotubes and the adhesive to obtain a wave-absorbing composition.

In some embodiments, the providing the carbon nanotubes may specifically include preparing single-walled carbon nanotubes by using an arc discharge technique on a template for shaping. A catalyst may be adhered to a surface of the template.

The preparing the single-walled carbon nanotubes by using the arc discharge technique may specifically include performing an arc discharge with graphite as a cathode and a composite electrode including a carbon-containing material and H₂O₂ as an anode to obtaining disordered carbon nanotubes, and making a reaction product mainly exist in the form of single-walled carbon nanotubes by controlling a content of reaction gas in a reaction device. The graphite may be evaporated in the arc discharge and generate fullerene C60, amorphous carbon, and single-walled or multi-walled carbon nanotubes. In some embodiments, the reaction gas may include hydrogen, and the carbon-containing material may include at least one of graphite or carbon.

In some embodiments, the arc discharge may be performed at a temperature in a range of 3500℃-3700℃, e.g., 3500℃, 3550℃, 3600℃, 3650℃, 3700℃, etc. The arc discharge may be performed in a protective gas, specifically, the protective gas may include an inert gas or nitrogen.

When the single-walled carbon nanotubes are prepared on a template with the catalyst adhered to the surface of the template for shaping, a molecular bond-breaking re-polymerization reaction may occur, resulting in the formation of the carbon nanotubes. In some embodiments, the catalyst may include at least one of Fe or CO.

In S50, the adhesive not only serves to bond, but also enhances the ductility and flexibility of a magnetically empty tube. When the adhesive includes self-soft polyurethane, the adhesive may be obtained by mixing an isocyanate compound, a glycol, a polyester oligomer containing terminal hydroxyl groups, and polyoxymethylene resin and performing a polymerization reaction.

In some embodiments, the mass ratio of the isocyanate compound, the glycol, the polyester oligomer containing terminal hydroxyl groups, and the polyformaldehyde resin may be in a range of 2: 1: 4: 1.5-2: 1.5: 3: 4.

In S50, in order to ensure sufficient mixing of the magnetic composite material, carbon nanotubes, and adhesive, the magnetic composite material, carbon nanotubes, and adhesive may be proportionally mixed in a blender in proportion and then stirred. The stirring may be performed at a rotation speed in a range of 300 r/min-400 r/min for a time in a range of 18 h-30 h.

Embodiments of the present disclosure also provide a wave-absorbing material. The wave-absorbing material may be obtained by preparing the above-mentioned wave-absorbing composition. For example, the wave-absorbing material may be obtained by curing the wave-absorbing composition.

In some embodiments, the wave-absorbing material may include a magnetic hollow tube. The magnetic hollow tube may be in the form of a hollow cylinder. The magnetic hollow tube may be used to wrap an electronic component such as a cable. In some embodiments, the wave-absorbing material may include a magnetic loss film. The magnetic loss film may include an adhesive insulating layer, the wave-absorbing material, and a non-adhesive insulating layer provided in a cascading arrangement. The magnetic loss film may be adhered to a surface of an electronic component such as a chip, and the adhesive insulating layer may be used to adhere the magnetic loss film to the chip.

When the wave-absorbing material includes magnetic hollow tube, the magnetic hollow tube may be in the form of a hollow cylinder. The magnetic hollow tube may include carbon nanotubes and a magnetic composite material adhered to a surface of at least a portion of the carbon nanotubes with an adhesive. In some embodiments, the magnetic hollow tube may have an absorption bandwidth in a range of 30 MHz-800 MHz, and an insertion loss may be increased to over 25 dB.

In addition, due to the low density, excellent mechanical properties, good electrical conductivity, and excellent corrosion resistance of the carbon nanotubes, as well as the advantages of low density and good thermal stability of the carbon crystals and the nano tungsten disulfide in the magnetic composite material, the magnetic hollow tube provided by embodiments of the present disclosure has advantages of lightness, good reliability, excellent flexibility, and excellent ductility, which can be completely adhered to the cables and avoid a leakage of electromagnetic waves, and thereby effectively suppressing electromagnetic interference (EMI) or radio frequency interference (RFI) on cables (or wires) .

The tube diameter of the carbon nanotube may affect an absorption frequency band and wave-absorbing performance of the magnetic hollow tube. In some embodiments, the tube diameter of carbon nanotube fibers may be in a range of 15 nm-25 nm, e.g., 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, 21 nm, 22 nm, 23 nm, 24 nm, 25 nm, etc, thus providing superior wave-absorbing performance for the magnetic hollow tube in the frequency band of 30 MHz-800 MHz. It should be noted that the embodiments of the present disclosure do not impose any special limitations on the length of the carbon nanotube.

The mass percent of carbon nanotubes in the magnetic hollow tube may affect the wave-absorbing performance and flexibility of the magnetic hollow tube. In some embodiments, the mass percent of the carbon nanotubes in the magnetic hollow tube may be in a range of 30%-50%, e.g., 30%, 32%, 34%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50%, etc, thereby providing excellent wave-absorbing performance and ductility for the magnetic hollow tube in a certain frequency band.

The mass ratio of the carbon nanotubes to the magnetic composite material may affect the wave-absorbing performance and ductility of the magnetic hollow tube in the frequency band of 30 MHz-800 MHz. In some embodiments, the mass ratio of the carbon nanotubes to the magnetic composite material may be in a range of 2.5: 2-3: 2.2, e.g., 2.5: 2, 2.6: 2.04, 2.7: 2.08, 2.8: 2.12, 2.9: 2.16, 3.0: 2.2, etc, enabling better synergy between the carbon nanotubes and the magnetic composite material, and thereby improving the wave-absorbing performance of the magnetic hollow tube in the frequency band of 30 MHz-800 MHz.

In some embodiments, a substrate of the magnetic hollow tube may be obtained by curing an adhesive including at least one of self-soft polyurethane, organic resin, or epoxy resin. For example, the adhesive may be the self-soft polyurethane. The self-soft polyurethane may have better thermoplasticity, chemical resistance, and elasticity, which can improve the ductility and flexibility of the magnetic hollow tube.

Due to the low density, excellent mechanical properties, good electrical conductivity, and excellent corrosion resistance of the carbon nanotubes, as well as the advantages of low density and good thermal stability of the carbon crystals and the nano tungsten disulfide in the magnetic composite material, the magnetic hollow tube provided by embodiments of the present disclosure has advantages of lightness, good reliability, excellent flexibility, and excellent ductility, which can be completely adhered to the cables and avoid a leakage of electromagnetic waves, and thereby effectively forming a cable suppression.

In addition, compared to traditional magnetic hollow tubes, the magnetic hollow tube provided in the embodiments of the present disclosure may have a thinner wall thickness but achieves better absorption and suppression performance of electromagnetic waves. The wall thickness may affect the wave absorption performance of the magnetic hollow tube in a specific frequency band. In some embodiments, the wall thickness of the magnetic hollow tube may be in a range of 0.5 mm-3 mm, e.g., 0.5 mm, 0.75 mm, 1 mm, 1.25 mm, 1.5 mm, 1.75 mm, 2 mm, 2.25 mm, 2.5 mm, 2.75 mm, 3 mm, etc. By controlling the wall thickness of the magnetic hollow tube, the absorption of electromagnetic waves in different frequency bands may be controlled.

In some embodiments, the wall thickness of the magnetic hollow tube may be 1.5 mm.

The magnetic hollow tube provided in the embodiments of the present disclosure may be produced by injecting the wave-absorbing composition into a hollow cylindrical mold for curing and shaping.

In some embodiments, in the magnetic composite, the graphene may be a porous graphene ellipsoid, the cluster of the carbon nanomaterial may be a graphene cluster including a plurality of porous graphene ellipsoids arranged in an orderly manner, and the nano metal sulfide may be a nano zinc sulfide.

In some embodiments, the porous graphene ellipsoids may be sequentially arranged at a specific distance within the graphene cluster.

In some embodiments, the porous graphene ellipsoids may be arranged in a three-dimensional array within the graphene cluster.

The embodiment of the present disclosure discloses that the porous graphene ellipsoids may be distributed in the three-dimensional array, which may be orderly arranged at a microscopic level. Particles are arranged in an array, and there are uniform pores on the surface of the particles, which may be used to adsorb other transition metal compounds.

In some embodiments, one of the plurality of porous graphene ellipsoids may have an equatorial radius in a range of 100 nm-110 nm and a polar radius in a range of 200 nm-230 nm. In some embodiments, one of the plurality of porous graphene ellipsoids may have an equatorial radius of 100 nm and a polar radius of 200 nm. In some embodiments, one of the plurality of porous graphene ellipsoids may have an equatorial radius of 100 nm and a polar radius of 210 nm. In some embodiments, one of the plurality of porous graphene ellipsoids may have an equatorial radius of 110 nm and a polar radius of 200 nm. In some embodiments, one of the plurality of porous graphene ellipsoids may have an equatorial radius of 120 nm and a polar radius of 220 nm.

In some embodiments, one of the plurality of porous graphene ellipsoids may have a pore diameter in a range of 16 nm-22 nm. In some embodiments, one of the plurality of porous graphene ellipsoids may have a pore diameter in a range of 14 nm-25 nm.

In some embodiments, one of the plurality of porous graphene ellipsoids may have a pore diameter of 14 nm, 17 nm, 18 nm, or 22 nm.

In some embodiments, one of the plurality of porous graphene ellipsoids may have a pore diameter of 18 nm.

In some embodiments, the ratio of the particle size of the nano zinc sulfide to the pore size of one of the plurality of porous graphene ellipsoids may be in a range of 1: 9-1: 11. In some embodiments, the ratio of the particle size of the nano zinc sulfide to the pore size of one of the plurality of porous graphene ellipsoids may be 1: 8, 1: 10, or 1: 11.

In some embodiments, the ratio of the particle size of the nano zinc sulfide to the pore size of one of the plurality of porous graphene ellipsoids may be 1: 10.

In some embodiments, the mass ratio of the nano zinc sulfide to the graphene cluster may be in a range of 1: 3-1: 4.

In some embodiments, the mass ratio of the nano zinc sulfide to the graphene cluster may be 1: 3, 1: 4, or 1: 5.

In some embodiments, the mass ratio of the nano zinc sulfide to the graphene cluster may be 1: 4.

In some embodiments, the magnetic composite material may include an organic insulating material.

In some embodiments, the organic insulating material may be encapsulated on the surface of the magnetic composite material and include a block polymer. The block polymer may include a block copolyether composed of ethylene oxide and propylene oxide.

In some embodiments, the magnetic composite material may also include a functional nanomaterial, and the functional nanomaterial may be fused into the graphene cluster. The functional nanomaterial may include transition metal compound nanomaterials and/or porous silicon carbide nanomaterials.

In some embodiments, the functional nanomaterial may be fused into the graphene cluster. For example, the functional nanomaterial may be adhered to a surface of at least a portion of the porous graphene ellipsoids, and at least a portion of interstices of the graphene cluster may be filled with the functional nanomaterial. Alternatively, the functional nanomaterial may have a particle size smaller than the pore size of one of the porous graphene ellipsoids and may be contained within a portion of pore channels of the porous graphene ellipsoids.

In some embodiments, the particle size of the transition metal compound nanomaterial may be in a range of 5 nm-15 nm, and the `` mass ratio of the transition metal compound nanomaterial to the graphene cluster may be in a range of 1: 3-1: 8.

In some embodiments, when the transition metal compound nanomaterial is selected from the hard magnetic ferrite nanomaterial, a particle size of the hard magnetic ferrite nanomaterial may be in a range of 6 nm-8 nm, and a mass ratio of the hard magnetic ferrite nanomaterial to the graphene cluster may be in a range of 1: 4 -1: 8.

In some embodiments, the particle size of the hard magnetic ferrite nanomaterial may be in a range of 6-7 nm. In some embodiments, the particle size of the hard magnetic ferrite nanomaterial may be 6 nm, 7 nm, or 8 nm.

In some embodiments, the mass ratio of the hard magnetic ferrite nanomaterial to the graphene cluster may be in a range of 1: 4-1: 6.

In some embodiments, the mass ratio of the hard magnetic ferrite nanomaterial to the graphene cluster may be 1: 4, 1: 5, 1: 6, or 1: 8.

In some embodiments, the particle size of the hard magnetic ferrite nanomaterial may be 6 nm, and the mass ratio of the hard magnetic ferrite nanomaterial to the graphene cluster may be 1: 5.

In some embodiments, when the transition metal compound nanomaterial is selected from the hard magnetic ferrite nanomaterial, the absorption bandwidth of the magnetic composite material may be in a range of 13 MHz-20 MHz, and the highest magnetic permeability may reach more than 130 H/m, and in particular, in a frequency of 13.56 MHz, the highest magnetic permeability of electromagnetic waves may reach to 180 H/m.

When the transition metal compound nanomaterial includes the hard magnetic ferrite nanomaterial, the magnetic composite material may be made into a wave-absorbing material and may be further applied to an electronic device, especially a card-swiping device, which can improve card-swiping performance of the card-swiping device at a frequency of 13.56 MHz, enhance a card-swiping distance, and no longer filter out the frequency of 13.56 MHz to prevent first and second harmonic emissions of 13.56 MHz from causing electromagnetic interference to the surrounding environment. Additionally, the wave-absorbing material has advantages such as flexibility and easy installation, which is easy to process and fabricate, thereby enriching application scenarios.

In some embodiments, when the transition metal compound nanomaterial is selected from the silver nanomaterial, the silver nanomaterial may have a particle size in a range of 5 nm-7 nm, and a mass ratio of the silver nanomaterial to the graphene cluster may be in a range of 1: 3-1: 5.

In some embodiments, the particle size of the silver nanomaterial may be in a range of 5 nm-6 nm. In some embodiments, the particle size of the silver nanomaterial may be 5 nm, 6 nm, or 7 nm.

In some embodiments, the mass ratio of the silver nanomaterial to the graphene cluster may be in a range of 1: 3-1: 4.

In some embodiments, the mass ratio of the silver nanomaterial to the graphene cluster may be 1: 3, 1: 4, or 1: 5.

In some embodiments, the particle size of the silver nanomaterial may be 5 nm, and the mass ratio of the silver nanomaterial to the graphene cluster may be 1: 4.

In some embodiments, when the transition metal compound nanomaterial is selected from the silver nanomaterial, the absorption bandwidth of the magnetic composite material may be in a frequency band of 2.2 GHz-3.1 GHz, and the insertion loss may increase to about 40 dB.

When the transition metal compound nanomaterial is selected from the silver nanomaterial, the magnetic composite material may be made into a wave-absorbing material and may be further applied to an electronic device, in particular, to a device with a high-speed signal module (e.g., WiFi or Bluetooth) , which may be capable of absorbing WiFi wireless signals in the frequency band of 2.2 GHz-3.1 GHz, thereby enhancing the overall electromagnetic compatibility performance, stability, and reliability of the electronic device.

In some embodiments, when the transition metal compound nanomaterial is selected from the ferrochromium cobalt alloy nanomaterial, a particle size of the ferrochromium cobalt alloy nanomaterial may be in a range of 8 nm-10 nm, and a mass ratio of the ferrochromium cobalt alloy nanomaterial to the graphene cluster may be in a range of 1: 4-1: 7.

In some embodiments, the particle size of the ferrochromium cobalt alloy nanomaterial may be in a range of 8 nm-9 nm.

In some embodiments, the particle size of the ferrochromium cobalt alloy nanomaterial may be 8 nm, 9 nm, or 10 nm.

In some embodiments, the mass ratio of the ferrochromium cobalt alloy nanomaterial to the graphene cluster may be in a range of 1: 4-1: 5.

In some embodiments, the mass ratio of the ferrochromium cobalt alloy nanomaterial to the graphene cluster may be 1: 4, 1: 5, or 1: 7.

In some embodiments, the particle size of the ferrochromium cobalt alloy nanomaterial may be 8 nm, and the mass ratio of the ferrochromium cobalt alloy nanomaterial to the graphene cluster may be 1: 5.

In some embodiments, when the transition metal compound nanomaterial includes the ferrochromium cobalt alloy nanomaterial, the absorption bandwidth of the magnetic composite material may be in a frequency band of 5 GHz-6.4 GHz, and the insertion loss may increase to about 40 dB, especially reaching about 45 dB in a frequency of 5.8 GHz.

When the transition metal compound nanomaterial includes the ferrochromium cobalt alloy nanomaterial, the magnetic composite material may be made into a wave-absorbing material and further applied to an electronic device, especially a high-speed wireless electronic device such as a circuit board. The magnetic composite material may effectively absorb electromagnetic waves in a frequency of 5.8 GHz, preventing the electromagnetic waves from affecting the normal operation of other modules in the electronic devices, thereby enhancing the electromagnetic compatibility stability of the electronic devices.

In some embodiments, when the transition metal compound nanomaterial includes the platinum cobalt alloy nanomaterial, a particle size of the platinum cobalt alloy nanomaterial may be in a range of 10 nm-12 nm, and a mass ratio of the platinum cobalt alloy nanomaterial to the graphene cluster may be in a range of 1: 3-1: 7.

In some embodiments, the particle size of the platinum cobalt alloy nanomaterial may be in a range of 10 nm-11 nm.

In some embodiments, the particle size of the platinum cobalt alloy nanomaterial may be 10 nm, 11 nm, or 12 nm.

In some embodiments, the mass ratio of the platinum cobalt alloy nanomaterial to the graphene cluster may be in a range of 1: 4-1: 5.

In some embodiments, the mass ratio of the platinum cobalt alloy nanomaterial to the graphene cluster may be 1: 4, 1: 5, or 1: 7.

In some embodiments, the particle size of the platinum cobalt alloy nanomaterial may be 10 nm, and the mass ratio of the platinum cobalt alloy nanomaterial to the graphene cluster may be 1: 5.

In some embodiments, when the transition metal compound nanomaterial includes the platinum cobalt alloy nanomaterial, the absorption bandwidth of the magnetic composite material may be in a frequency band of 10 GHz-27 GHz, and the insertion loss may increase to about 40 dB.

When the transition metal compound nanomaterial includes the platinum cobalt alloy nanomaterial, the magnetic composite material may be made into a wave-absorbing material and may be further applied to an electronic device, especially an antenna and other electronic devices. The magnetic composite material may be capable of absorbing electromagnetic waves of the frequency band of 10 GHz-27 GHz well. The magnetic composite material may solve a problem of radiation spuriousness and reduce an influence of the radiation spuriousness on the electronic device, thereby improving the anti-interference ability of the electronic device.

In some embodiments, when the transition metal compound nanomaterial includes the ferronickel alloy nanomaterial, the particle size of the ferronickel alloy nanomaterial may be in a range of 12 nm-13 nm, and the mass ratio of the ferronickel alloy nanomaterial to the graphene cluster may be in a range of 1: 3-1: 7.

In some embodiments, the particle size of the ferronickel alloy nanomaterial may be 12 nm or 13 nm.

In some embodiments, the mass ratio of the ferronickel alloy nanomaterial to the graphene cluster may be in a range of 1: 3-1: 5.

In some embodiments, the mass ratio of the ferronickel alloy nanomaterial to the graphene cluster may be 1: 3, 1: 5, or 1: 7.

In some embodiments, the particle size of the ferronickel alloy nanomaterial may be 12 nm, and the mass ratio of the ferronickel alloy nanomaterial to the graphene cluster may be 1: 5.

In some embodiments, when the transition metal compound nanomaterial includes the ferronickel alloy nanomaterial, the absorption bandwidth of the magnetic composite material may be in a frequency band of 40 GHz-60 GHz, and the insertion loss may increase to about 40 dB.

When the transition metal compound nanomaterial is selected from the ferronickel alloy nanomaterial, the magnetic composite material may be made into a wave absorbing material and further applied to an electronic device. The magnetic composite material may well absorb radar waves of 40 GHz-60 GHz, improving electromagnetic compatibility of the electronic device against radar wave interference, such as shielding the radar wave interference generated by automotive electronics, and thereby enhancing the electromagnetic compatibility of the automotive electronics and peripheral electronic devices.

In some embodiments, when the functional nanomaterial includes the porous silicon carbide nanomaterial, the particle size of the porous silicon carbide nanomaterial may be in a range of 13 nm-15 nm, and the mass ratio of the porous silicon carbide nanomaterial to the graphene cluster may be in a range of 1: 4-1: 8.

In some embodiments, the particle size of the porous silicon carbide nanomaterial may be in a range of 13 nm-14 nm.

In some embodiments, the particle size of the porous silicon carbide nanomaterial may be 13 nm, 14 nm, or 15 nm.

In some embodiments, the mass ratio of the porous silicon carbide nanomaterial to the graphene cluster may be in a range of 1: 4-1: 6. In some embodiments, the mass ratio of the porous silicon carbide nanomaterial to the graphene cluster may be 1: 4, 1: 6, or 1: 8.

In some embodiments, the particle size of the porous silicon carbide nanomaterial may be 13 nm, and the mass ratio of the porous silicon carbide nanomaterial to the graphene cluster may be 1: 6.

In some embodiments, when the magnetic composite material further includes the porous silicon carbide nanomaterial, the absorption bandwidth of the magnetic composite material may be in a frequency band of 70 GHz-85 GHz, and the insertion loss may increase to 45 dB, especially at a frequency of 77 GHz, the insertion loss of the electromagnetic waves may increase to about 50 dB.

When the magnetic composite material further includes the porous silicon carbide nanomaterial, the magnetic composite material may be made into an absorbing material and may be further applied to an electronic device. The magnetic composite material may be capable of absorbing millimeter radar waves in the frequency band of 70 GHz-85 GHz, improving a problem of carrying millimeter wave electronic devices, shielding the millimeter wave interference generated by the electronic devices, and thereby improving the electromagnetic compatibility of the electronic devices and the peripheral electronic devices.

Embodiments of the present disclosure may provide a method of preparing a magnetic composite material including following operations.

The graphene cluster may be prepared based on a colloid crystal templating technique using poly (methyl vinyl acid ethyl ester) as a colloid crystal template under a first heating condition. The first heating condition may include heating for 20 h-28 h at 180℃-220℃. The graphene cluster may be mixed with the nano zinc sulfide under a second heating condition to obtain the magnetic composite material.

The colloid crystal template may be a hard template material with a three-dimensional periodic structure formed by self-assembly of nanospheres. The colloid crystal template may include poly (methyl vinyl acid ethyl ester) , methyl methacrylate, et al.

In some embodiments, the preparing the graphene cluster based on the colloid crystal templating technique using poly (methyl vinyl acid ethyl ester) as the colloid crystal template under a first heating condition may include preparing graphene and water to form a first formulation, mixing the first formulation with an adhesive to form a second formulation, adding the second formulation to the colloid crystal template, heating the second formulation under an inert atmosphere, and then cooling the second formulation down in a reducing atmosphere to obtain the graphene cluster.

In this process, the mass ratio of the graphene to water may be in a range of 1: 2-1: 4, and the mass ratio of the graphene to the adhesive may be in a range of 10: 1-10: 3. The adhesive may preferably include a resin-based adhesive such as phenolic resin. The mass ratio of the graphene to the colloid crystal may be in a range of 6: 1-12: 1. The colloid crystal template may be poly (methyl vinyl acid ethyl ester) colloid crystal template. The heating temperature may be in a range of 180℃–220℃, and the heating time may be in a range of 20 h-28 h. The inert atmosphere used during heating may be nitrogen, argon, or the like. The reducing atmosphere used during cooling may be carbon monoxide, hydrogen, or the like.

To further enhance the stability of graphene, a reducing catalyst may be added to the first formulation. The reducing catalyst may include SnCl₂ or FeCl₂. In some embodiments, the mass ratio of the graphene to the reducing catalyst may be in a range of 1: 1-2: 1. After heating in the inert atmosphere and cooling under the reducing atmosphere, a more stable first formulation may be obtained. The heating temperature may be in a range of 220℃-280℃, and the heating time may be in a range of 4 h-8 h.

In some embodiments, when the magnetic composite material includes a functional nanomaterial, the graphene cluster may be mixed with the nano zinc sulfide and the functional nanomaterial, and then the organic insulating material may be added to the mixture of the graphene cluster, the nano zinc sulfide, and the functional nanomaterial.

Embodiments of the present disclosure prepare the graphene cluster using poly (methyl vinyl acid ethyl ester) as the colloid crystal template, and then mixing the graphene cluster with the nano zinc sulfide under an optimized heating condition, which can efficiently and easily produce a magnetic composite material with an adjustable absorption bandwidth, strong wave-absorbing performance, and lightweight.

Embodiments of the present disclosure may provide a wave-absorbing material based on the magnetic composite material.

In some embodiments, the wave-absorbing material may include a wave-absorbing rubber gasket, a wave-absorbing conductive foam, a wave-absorbing glass, a wave-absorbing sheath, etc.

The magnetic composite material of the embodiments of the present disclosure may be used to prepare wave-absorbing materials for different unique frequency bands. These wave-absorbing materials have advantages of strong wave-absorbing performance, light weight, and electrical insulation.

Embodiments of the present disclosure provide an electronic device including a wave-absorbing material.

In some embodiments, the electronic device may include a card-swiping device, a module with high-speed signals such as WIFI or Bluetooth, an antenna, a circuit board, an automotive electronic, and other device. By selecting wave-absorbing materials for suitable frequency bands according to the features of different electronic devices, not only the quality of signal transmission and the stability of functions of the electronic devices under the high-speed network of 5G can be enhanced, but also the weight of the electronic devices can be not significantly increase, and at the same time, additional insulating layer is not required.

In some embodiments, the wave-absorbing material may include the magnetic composite material. The magnetic composite material may include the nano tungsten disulfide and the nano carbon crystal cluster or the magnetic composite material may include the nano zinc sulfide and the graphene cluster.

In some embodiments, the electronic device may include an electromagnetic shielding encapsulant. The electromagnetic shielding encapsulant may include a printed circuit board, an insulating layer laminated on an outer surface of the printed circuit board, and a wave-absorbing material. It may be to be appreciated that the wave-absorbing material may include a matrix and a magnetic composite material dispersed in the matrix. Alternatively, the electromagnetic shielding encapsulant may include a cable and a magnetic hollow tube wrapped around an outer surface of the cable, or the electromagnetic shielding encapsulant may include a chip and a magnetic loss film adhered to a surface of the chip.

In some embodiments, the electronic device may include a wave-absorbing material including the nano tungsten disulfide and the carbon nano crystal cluster. When the electromagnetic shielding encapsulant includes a printed circuit board, an insulating layer and a wave-absorbing material laminated on the outer surface of the printed circuit board, , due to the excellent wave-absorbing performance of the wave-absorbing material including the above-described the magnetic composite, the absorption bandwidth of the wave-absorbing material covers electromagnetic waves in a frequency band of 30 MHz-8 GHz, and an insertion loss may be maintained at more than 20 dB. In some embodiments, the electronic device may include a wave-absorbing material including the nano zinc sulfide and the nano graphene cluster. Due to the excellent wave-absorbing performance of the wave-absorbing material including the above-described the magnetic composite, the absorption bandwidth of the wave-absorbing material covers electromagnetic waves in a frequency band of 13 MHz -1.2 GHz, and the insertion loss may be maintained at 20 dB or more. By doping different transition metal compound nanomaterials, the wave-absorbing material may be selected to match the frequency bands according to the features of different electronic devices, thereby further increasing the insertion loss to more than 40 dB.

Embodiments of the present disclosure do not impose any specific limitations on the structure of the printed circuit board. The printed circuit board may include one or more cascading signal layers. A signal layer refers to a film layer composed of one or more wires or conductive sheets capable of transmitting an electrical signal, and the term "more" means two or more integers.

The insulating layer may insulate the electromagnetic shielding encapsulant. Embodiments of the present disclosure do not impose any special limitations on the material and thickness of the insulating layer. In some embodiments, the insulating layer may be made of at least one of polymer synthetic resin, glass fiber, or epoxy resin, and may have a thickness in a range of 0.5 mm-1 mm, e.g., 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, etc.

The mass percent of the magnetic composite material in the wave-absorbing material may affect the wave-absorbing bandwidth and insertion loss of the wave-absorbing material. In some embodiments, when the wave-absorbing material includes the nano tungsten disulfide and the nano carbon crystal cluster, the mass percent of the magnetic composite material in the wave-absorbing material may be 70%-85%, e.g., 70%, 73%, 76%, 79%, 82%, 85%, etc., thereby enabling the wave-absorbing material to have superior wave-absorbing performance in a frequency band of 30 MHz-8 GHz. When the wave-absorbing material includes the nano zinc sulfide and the nano graphene cluster, the mass percent of the magnetic composite material in the wave-absorbing material may be 40-70%, e.g., 30%, 40%, 50%, 60%, or 70%, such that the wave-absorbing material may have more excellent wave-absorbing performance in the specific frequency band.

In some embodiments, the wave-absorbing material may further include an insulating substance dispersed in the substrate to enable more stable operation of the printed circuit board. In some embodiments, the insulating substance may include at least one of polymer synthetic resin, glass fiber, or epoxy resin. A mass percent of the insulating substance in the wave-absorbing material may be in a range of 5%-7%, e.g., 5%, 5.5%, 6%, 6.5%, 7%, etc.

In some embodiments, the substrate may be obtained by curing an adhesive. The adhesive may include at least one of an acrylic adhesive, polyurethane adhesive, butyl rubber, or vinyl acetate resin.

The present disclosure provides an electromagnetic shielding encapsulant, which may simultaneously achieve electromagnetic susceptibility (EMS) shielding and electromagnetic interference (EMI) absorption, thereby having excellent electromagnetic compatibility (EMC) . The electromagnetic shielding encapsulant can effectively prevent mutual interference not only between the printed circuit board in the electronic device but also between the printed circuit board and other external electronic devices.

Embodiments of the present disclosure may also provide a process of preparing the above-mentioned electromagnetic shielding encapsulant including the following operations.

First, an insulating layer may be formed on an outer surface of a printed circuit board, and then a wave-absorbing composition may be formed on an outer surface of the insulating layer. After the wave-absorbing composition is cured, the wave-absorbing material may be formed to obtain the electromagnetic shielding encapsulant.

Embodiments of the present disclosure do not impose any particular limitation on the manner of forming the insulating layer on the outer surface of the printed circuit board. In some embodiments, forming the insulating layer on the outer surface of the printed circuit board may include following operation (s) .

The insulating composition may be formed on the outer surface of the printed circuit board, and the insulating layer may be formed after curing the insulating composition.

The wave-absorbing composition may be formed on the outer surface of the insulating layer by spraying the wave-absorbing composition on the surface of the printed circuit board with the insulating layer, and then curing the wave-absorbing composition to form a wave-absorbing layer. Alternatively, the printed circuit board with the insulating layer may be immersed in the wave-absorbing composition, and then the wave-absorbing composition may be cured to form the wave-absorbing layer.

In some embodiments, the electronic device may include a printed circuit board. The printed circuit board may include a dielectric layer and a conductive layer laminated on at least one surface of the dielectric layer. The dielectric layer including the magnetic composite material.

Due to the wide absorption bandwidth and high absorption strength of the magnetic composite material, the dielectric layer fused with the magnetic composite material may have the advantages of a wide absorption bandwidth and high absorption strength, which can enable simultaneous electromagnetic susceptibility shielding and electromagnetic interference (EMI) absorption. For example, the magnetic composite material containing the nano tungsten disulfide and the nano carbon crystal cluster may exhibit good shielding performance at a low electromagnetic frequency end from 30 MHz to 1 GHz, with an insertion loss of 20 dB to 35 dB, which can reduce radiated interference from the printed circuit board by 10 dB to 20 dB, reducing signal crosstalk between different layers within the printed circuit board, preventing mutual interference between the printed circuit boards in the electronic device, and preventing mutual interference between the printed circuit board and external electronic devices, and resulting in excellent electromagnetic compatibility (EMC) of the printed circuit boards disclosed in the present disclosure.

In addition, the dielectric layer of the printed circuit board itself may have the advantages of a wide absorption bandwidth and high wave-absorbing strength, eliminating the need for additional electromagnetic shielding devices such as shielding covers, which can reduce an electromagnetic shielding space and not affect the manufacturing process of the printed circuit board.

In some embodiments, the mass percent of the magnetic composite material in the dielectric layer may be in a range of 30%-40%, e.g., 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, etc., such that the dielectric layer may be have excellent wave-absorbing and shielding performance, facilitating better molding of the printed circuit board.

In order to better convert the electromagnetic waves absorbed by the magnetic composite material into thermal energy, in some embodiments, the dielectric layer may also include metal-based powder. For example, the metal-based powder may have a magnetic permeability greater than or equal to 10 H/m. For example, the metal-based powder may include at least one of iron powder, copper powder, aluminum powder, or magnesium powder, or an oxide thereof. In some embodiments, the metal-based powder may have a mass percent in a range of 3%-5%in the wave-absorbing gel, e.g., 3%, 4%, 5%, etc.

It should be noted that when the substrate of the wave-absorbing layer includes the metal-based powder, an insulating substance may be also included in the substrate of the dielectric layer in order to reduce the conductivity of the metal-based powder. For example, the insulating substance may include at least one of SiO₂, Al₂O₃, or SiC. In some embodiments, the insulating substance may have a mass percent in a range of 5%-9%in the wave-absorbing layer, e.g., 5%, 6%, 7%, 8%, 9%, etc.

Embodiments of the present disclosure also provide a process of preparing a printed circuit board as described above:

In S60, the wave-absorbing composition may be formed on a surface of the reinforcing material and dried to obtain a semi-cured sheet.

In S70, one or more semi-cured sheets may be stacked to obtain a semi-cured sheet layer.

In S80, at least one surface of the semi-cured sheet layer may be covered with a conductive layer and cured to obtain a circuit substrate.

In S90, the circuit substrate may be made into a printed circuit board.

In S60, the wave-absorbing composition may be formed on the surface of the reinforcing material by coating, impregnating, or the like. In some embodiments, the reinforcing material may include fiberglass cloth. For example, the fiberglass cloth may be selected from type 7628 fiberglass cloth, type 2116 fiberglass cloth, type 1080 fiberglass cloth, or type 106 fiberglass cloth. In order to improve the adsorption performance of the fiberglass cloth, the fiberglass cloth may be silanized.

For better removal of solvents from the resin composition, an operation of performing baking may be preferably performed at a temperature in a range of 60℃-80℃, e.g., 60℃, 65℃, 70℃, 75℃, 80℃, etc.

In S70, a count of semi-cured sheets in the semi-cured sheet layer may be not specifically limited, but may be one or more layers, and the count of semi-cured sheets may be selected by the thickness of the printed circuit board.

In S80, the material of the conductive layer may be preferably copper foil, thereby making the circuit substrate as a copper-clad board.

In some embodiments, the curing may be performed at a temperature in a range of 190℃ -210℃, e.g., 190℃, 195℃, 200℃, 205℃, 210℃, etc., and a pressure in a range of 4.8 MPa-5.0 MPa, e.g., 4.8 MPa, 4.9 MPa, 5.0 MPa, etc.

In S90, the printed circuit board may be obtained by processing the circuit substrate through operations such as drilling, hole rectifying, micro-etching, pre-impregnating, activating, accelerating, chemical coppering, and copper thickening.

Understandably, the printed circuit board may be used in all electronic devices, such as electronic watches and cell phones, as well as communication devices, aerospace systems, and other devices that require the use of integrated circuits and electronic components.

When made into wave-absorbing materials for application in electronic devices, the magnetic composite material may provide several advantages. Firstly, the quality of signal transmission under 5G high-speed network can be enhanced, meeting the current functional requirements for variable bandwidth. Secondly, t the stability of electronic devices' functions can be enhanced. Thirdly, any additional weight to the electronic devices does not added.

Beneficial effects of the embodiments of the present disclosure include, but may be not limited to: (1) the magnetic composite material including the plurality of of porous graphene ellipsoids and the nano zinc sulfide used in the field of EMC may provide good electromagnetic shielding effects for different frequency bands, and by adjusting the ratio of doped particles to the graphene cluster, the electromagnetic wave shielding effect in different frequency bands may be regulated to achieve the absorption of electromagnetic waves in fixed frequency bands; (2) the addition of different functional nanomaterials to the magnetic composite material, which have excellent piezoelectric and semiconducting properties, the functional nanomaterials with an ultrathin structure and large surface carrier migration flux can ensure the efficient utilization of its intrinsic carriers, then magnetic composite materials with different electromagnetic shielding efficacies in fixed frequency bands may be obtained; and (3) according to the magnetic composite material made of the wave-absorbing materials, the quality of signal transmission under the 5G high-speed network can be enhanced to meet a current demand for variable bandwidth function, which is applicable to adjust a variety of signals and bandwidths of the communication network link, thereby greatly enhancing the stability of the function of the electronic device system.

The technical solutions in the embodiments of the present invention will be clearly and completely described below in connection with embodiments of the present disclosure. Clearly, the described embodiments may be only a portion of the embodiments of the present disclosure. Some of the content in these embodiments may also be replaced or combined with corresponding content in other embodiments to form new embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without making creative labor fall within the scope of protection of the present disclosure. The experimental manners in the following embodiments, if not otherwise specified, may be conventional manners. The experimental materials used in the following embodiments, if not otherwise specified, may be obtained by purchase from a conventional biochemical reagent company. The quantitative tests in the following embodiments were set up with three repetitions, and the results were averaged. It should be appreciated that the following embodiments may be intended to better explain the present disclosure and may be not intended to limit the present disclosure.

EMBODIMENTS

Embodiment 1

A solution of second graphene oxide was obtained by mixing 5 mL of a hydrogen peroxide solution with a mass percent of 3%with 100 mL of a dispersion of first graphene oxide with a mass percent of 35% (whose solvent was hydrochloric acid of 1 mol/L) . Then, 150 mL of a suspension of porous graphene oxide with a mass percent of 60% (whose solvent was hydrochloric acid of 1 mol/L) was added to obtain a mixture. The mixture was placed in a stainless steel reactor lined with polytetrafluoroethylene, heated to 130℃, and maintained at a constant temperature 130℃ for 13 h. The excess hydrogen peroxide solution was removed from the reaction solution by high-speed centrifugation and deionized water rinsing. After concentration, a concentrated product was dried under a vacuum condition in a high-temperature environment to obtain the carbon crystal cluster. FIG. 1 is a scanning electron micrograph illustrating a nano carbon crystal cluster made according to Embodiment 1 of the present disclosure. As shown in FIG. 1, the carbon crystals in the carbon crystal cluster is in the form of three-dimensional pyramid, and the carbon crystals in the carbon crystal cluster have a pore channel structure.

0.6 g of WCl₆ and 1.12 g of thioacetamide was weighed, dissolved in 105 mL of deionized water, stirred at room temperature for 2 h and then moved to a temperature-controlled device lined with polytetrafluoroethylene, heated to 280℃ and held for one day. When the reaction was finished, the product was naturally cooled to room temperature, and a precipitate was obtained by filtration. The precipitate was washed several times with deionized water at 100℃, and finally a solid product was obtained by vacuum drying the precipitate at 61℃. For further sulfurization, this solid product was dispersed in a mixed solution of MPS/dichloromethane with a volume ratio of 1: 15, and refrigerated for one day at 4℃. Then the sulfurized solid product was annealed under an argon gas atmosphere at 295℃ for 5 h. Finally, the nano tungsten disulfide was prepared. FIG. 2 is a micrograph illustrating nano tungsten disulfide viewed by a body-viewing microscope. FIG. 3 is a scanning electron micrograph illustrating nano tungsten disulfide made. FIG. 4 is a high magnification scanning electron micrograph illustrating nano tungsten disulfide made. As shown in FIGs. 2-4, the nano tungsten disulfide is cubic in shape.

The obtained carbon crystal cluster was uniformly dispersed in water to create 110 mL intermediate suspension of the carbon crystal cluster with a concentration of 1 g/L. Then, 110 mL hydrochloric acid solution with a concentration of 1 g/L was added to the intermediate suspension to obtain a suspension of nano carbon crystal cluster. The suspension of the nano carbon crystal cluster was stirred at the room temperature for 2 h and then transferred to the stainless steel reactor lined with polytetrafluoroethylene for heating at 265℃ for one day. After completion of the reaction, the mixture was cooled to the room temperature, and a precipitate was obtained by filtering the mixture. The precipitate was washed several times with deionized water and then vacuum dried at 60℃ to obtain a dried precipitate. The dried precipitate was dispersed in a mixed solution of MPS/dichloromethane with a volume ratio of 1: 14 and refrigerated at 3℃ for one day. Then the dried precipitate was mixed with the nano tungsten disulfide and annealed at 300℃ under an inert gas atmosphere for 5 h to obtain a magnetic composite material. FIG. 5 is a micrograph illustrating a magnetic composite material made according to Embodiment 1 viewed by a body-viewing microscope. FIG. 6 is a high magnification scanning electron micrograph illustrating a magnetic composite material. FIG. 7 is a diagram illustrating an insertion loss of a magnetic composite material.

The prepared magnetic composite material was compressed, and the resulting physical diagram is shown in FIG. 8.

Comparative Embodiment 1

The first graphene oxide was dispersed in a mixture of water and N, N-dimethylformamide at a volume ratio of 1: 1 to obtain a dispersion of the first graphene oxide. In the dispersion of the first graphene oxide, a concentration of the first graphene oxide was 1.0 mg/mL. Tungsten hexachloride (of 0.6 g) and thioacetamide (of 1.2 g) were sequentially added to the dispersion of the first graphene oxide and stirred uniformly to obtain a mixed solution. The mixed solution was heated at 120℃ to perform the reaction. A solid product after the reaction was centrifuged a plurality of times, washed with alcohol and water to remove impurities, and then freeze-dried for 24 h at -50℃ to obtain a three-dimensional self-assembled structure of tungsten disulfide-reduced graphene oxide.

Comparative Embodiment 2

The tungsten disulfide nanosheets were mixed with stacked graphene under an ultrasonic condition to obtain graphene-modified tungsten disulfide nanosheets. The two two-dimensional layered structures may form a heterogeneous layer structure well.

Comparative Embodiment 3

By replacing the graphene oxide in Embodiment 1 with stacked graphene, and replacing the porous graphene oxide with stacked porous graphene, the carbon crystals obtained were in the form of a sheet, not three-dimensional pyramid and not have a pore channel structure.

Comparative Embodiment 4

By replacing WCl₆ in Embodiment 1 with metal tungsten powder, and replacing thioacetamide with sulfur powder, the tungsten disulfide obtained were in the form of a block, not a cube.

Test Embodiment 1

The density, thermal conductivity, and wave-absorbing performance of the magnetic composite material obtained in Embodiment 1 and comparative Embodiments 1-4 were tested as shown below.

Density test includes taking a sample to be tested and place the sample to be tested in 0.8 L of water until 1 L of the mixture is obtained, weighting a total mass of the 1 L of the mixture, subtracting a mass of the 0.8 L of water from the total mass to obtain a mass of the sample to be tested, and dividing the mass of the sample to be tested by 0.2 L to obtain a density of the sample to be tested;

The thermal conductivity test includes measuring using a steady state heat flow technique referring to GB/T8722; and

The absorption performance test includes testing an absorption bandwidth and an insertion loss referring to GB/T32596.

The test results are shown in Table 1.

Table 1

According to the test results in Table 1, the magnetic composite material obtained in Embodiment 1 may have a higher insertion loss, indicating that in the process of preparing the nano tungsten disulfide, sulfidation may be performed on the solid product formed by the reaction of tungsten chloride and the thioacetamide, and the sulfidation may be performed on the suspension of the precipitate containing the carbon crystal cluster to obtain the magnetic composite material with better absorption performance compared to the process without sulfidation. Furthermore, in Embodiment 1 of the present disclosure, when the carbon crystal cluster is prepared, using a mixture of further oxidized second graphene oxide and the porous graphene oxide to prepare the carbon crystal cluster may produce a magnetic composite material with better wave-absorbing performance than using a single graphene oxide.

Embodiment 2

Embodiment 2 was performed with reference to Embodiment 1, and different from Embodiment 1, in the operation of preparing the carbon crystal cluster of Embodiment 2, the ratio of the mass percent of hydrogen peroxide in the hydrogen peroxide solution to the mass percent of first graphene oxide in the dispersion of the first graphene oxide was 1: 15, and an edge length of one of the carbon crystals was 8 nm.

Embodiment 3

Embodiment 3 was performed with reference to Embodiment 1, different from Embodiment 1, in the operation of preparing the carbon crystal cluster of Embodiment 3, the ratio of the mass percent of hydrogen peroxide in the hydrogen peroxide solution to the mass percent of first graphene oxide in the dispersion of the first graphene oxide was 1: 25, and an edge length of one of the carbon crystals was 10 nm.

Embodiment 4

Embodiment 4 was performed with reference to Embodiment 1, different from Embodiment 1, in the operation of preparing the carbon crystal cluster of Embodiment 4, the ratio of the mass percent of hydrogen peroxide in the hydrogen peroxide solution to the mass percent of first graphene oxide in the dispersion of the first graphene oxide was 1: 30, and an edge length of one of the carbon crystals was 11.5 nm.

Embodiment 5

Embodiment 5 was performed with reference to Embodiment 1, different from Embodiment 1, in the operation of preparing the carbon crystal cluster of Embodiment 5, the ratio of the mass percent of hydrogen peroxide in the hydrogen peroxide solution to the mass percent of first graphene oxide in the dispersion of the first graphene oxide was 1: 35, and an edge length of one of the carbon crystals was 13 nm.

Embodiment 6

Embodiment 6 was performed with reference to Embodiment 1, different from Embodiment 1, in the operation of preparing the carbon crystal cluster of Embodiment 6, the ratio of the mass percent of hydrogen peroxide in the hydrogen peroxide solution to the mass percent of first graphene oxide in the dispersion of the first graphene oxide was 1: 40, and an edge length of one of the carbon crystals was 15 nm.

Test Embodiment 2

The density, thermal conductivity, and wave-absorbing performance of the magnetic composite material obtained in Embodiments 2-6 were tested following the process described in test Embodiment 1, and the test results are shown in Table 2.

Table 2

According to Embodiment 6 in Table 2, in the operation of preparing the carbon crystal cluster, when the ratio of the mass percent of hydrogen peroxide in the hydrogen peroxide solution to the mass percent of the first graphene oxide in the dispersion of the first graphene oxide is greater than 1: 35, the magnetic composite material prepared has a narrower absorption bandwidth and a lower insertion loss. According to Embodiment 4, when the ratio of the mass percent of hydrogen peroxide in the hydrogen peroxide solution to the mass percent of the first graphene oxide in the dispersion of the first graphene oxide is 1: 30, the magnetic composite material prepared has a largest absorption bandwidth and a largest insertion loss, and the wave-absorbing performance may be better.

Embodiment 7

Embodiment 7 was performed with reference to Embodiment 4, different from Embodiment 4, in the Embodiment 7, the reaction temperature was increased to 300℃ in the operation of preparing the nano tungsten disulfide, the maximum diameter of the tungsten disulphide was 2 nm, and the intermediate diameter of 2 nm.

Embodiment 8

Embodiment 8 was performed with reference to Embodiment 4, different from Embodiment 4, in the operation of preparing the nano tungsten disulfide of Embodiment 8, the ratio of WCl₆ and thioacetamide was 1: 2, the maximum diameter of the nano tungsten disulfide was 4 nm, and the intermediate diameter was 3 nm.

Embodiment 9

Embodiment 9 was performed with reference to Embodiment 4, different from Embodiment 4, in the operation of preparing the nano tungsten disulfide of Embodiment 9, the ratio of WCl₆ and thioacetamide was reduced to 1: 3, and the maximum diameter of the nano tungsten disulfide was 5 nm, and the intermediate diameter was 4 nm.

Embodiment 10

Embodiment 10 was performed with reference to Embodiment 4, different from Embodiment 4, in the operation of preparing the nano tungsten disulfide of Embodiment 10, the ratio of WCl₆ and thioacetamide was reduced to 1: 3, an ionic cleaning temperature was 120℃, the maximum diameter of the nano tungsten disulfide was 6 nm, and the intermediate diameter was 5 nm.

Embodiment 11

Embodiment 11 was performed with reference to Embodiment 4, different from Embodiment 4, in the operation of preparing the nano tungsten disulfide of Embodiment 11, the annealing temperature was lowered to below 250℃, the maximum diameter of the nano tungsten disulfide was 8 nm, and the intermediate diameter was 7 nm.

Test Embodiment 3

The density, thermal conductivity, and wave-absorbing performance of the magnetic composite material obtained in Embodiments 7-11 was tested with reference to test Embodiment 1, and the results of the tests are shown in Table 3.

Table 3

According to Embodiment 9 of Table 3, in the operation of preparing the nano tungsten disulfide, when the ratio of WCl₆ and thioacetamide is 1: 3, the maximum diameter of the nano tungsten disulfide is 5 nm, and the intermediate diameter is 4 nm, the nanomagnetic material obtained may have the largest insertion loss and better wave-absorption performance.

Embodiment 12

Embodiment 12 was performed with reference to Embodiment 9, different from Embodiment 9, in the Embodiment 12, the mass ratio of the nano tungsten disulfide to the carbon crystal cluster in the operation of mixing was 1: 1.

Embodiment 13

Embodiment 13 was performed with reference to Embodiment 9, different from Embodiment 9, in the Embodiment 13, the mass ratio of the nano tungsten disulfide to the carbon crystal cluster in the operation of mixing was 1: 1.3.

Embodiment 14

Embodiment 14 was performed with reference to Embodiment 9, different from Embodiment 9, in the Embodiment 14, the mass ratio of the nano tungsten disulfide to the carbon crystal cluster in the operation of mixing was 1: 1.4.

Embodiment 15

Embodiment 15 was performed with reference to Embodiment 9, different from Embodiment 9, in the Embodiment 15, the mass ratio of the nano tungsten disulfide to the carbon crystal cluster in the operation of mixing was 1: 1.5.

Embodiment 16

Embodiment 16 was performed with reference to Embodiment 9, different from Embodiment 9, in the Embodiment 16, the mass ratio of the nano tungsten disulfide to the carbon crystal cluster in the operation of mixing was 1: 1.7.

Test Embodiment 4

The density, thermal conductivity, and wave-absorbing performance of the magnetic composite material obtained in Embodiments 12-16 were tested with reference to test Embodiment 1, and the results of the tests are shown in Table 4.

Table 4

According to Embodiment 14 of Table 4, in the operation of mixing the nano tungsten disulfide and the carbon crystal cluster, the mass ratio of the nano tungsten disulfide to the carbon crystal cluster is 1: 1.4, resulting in the nanomagnetic material with the largest insertion loss and better wave-absorbing performance.

Embodiment 17

Embodiment 17 was performed with reference to Embodiment 14, different from Embodiment 14, in the Embodiment 17, after the operation of mixing the nano tungsten disulfide and the carbon crystal cluster, ZrC was further added to obtain the magnetic composite material.

Test Embodiment 5

The density, thermal conductivity, and wave-absorbing performance of the magnetic composite material obtained in Embodiment 17were tested with reference to test Embodiment 1, and the results of the tests are shown in Table 5.

Table 5

Embodiment 18

10 g of FeCl₂ was dissolved in water with 20 g of FeCl₃ under protection of nitrogen, and 200 g of NaOH solution with a mass percent of 30%was added to obtain a reaction solution, which was reacted at 60℃ for 2 h. After the reaction, the reaction solution was cooled at the room temperature under the inert gas and dried to obtain Fe₃O₄ powder.

The prepared Fe₃O₄ powder was mixed with the magnetic composite material prepared in Embodiment 1 to generate a mixed product, and after mixing, the mixed product was added to a grinder and ground for 24 h. After grinding, the product and 30 g of ammonia were added to a blender for stirring at 2℃ for 12 h, and finally cooled and dried under the inert gas to obtain the magnetic composite material. FIG. 9 is a micrograph illustrating a magnetic composite material made according to Embodiment 18 viewed by a body-viewing microscope. FIG. 10 is a diagram illustrating an insertion loss of a magnetic composite material made according to Embodiment 18.

Embodiment 19

Embodiment 19 was performed with reference to Embodiment 18, different from Embodiment 18, in the Embodiment 19, Fe₃O₄ was replaced with permalloy, and thepermalloy was prepared as following operations including: weighing 10 g of ferric nitrate nonahydrate, 200 g of nickel nitrate hexahydrate, and 0.01 g of glucose to be dissolved in 25 mL of distilled water, being mixed homogeneously, heated and evaporated, then sealed, and pyrolyzed at 600℃ for 3 h and then cooled naturally to obtain the pyrolysis product.

The pyrolysis product was then annealed for 12 h at a temperature of 1050℃ under the nitrogen atmosphere to obtain an annealed product.

The annealed product was ground, and then soaked in nitric acid of 12 mol/L for 2.5 h for purification. After dilution, the annealed product was filtered and dried to obtain particles. The obtained particles were added to a ball grinding jar with 2 mL of oleic acid and 20 mL of kerosene. The ball grinding was performed with agate as the ball medium at a rotation speed of 500 r/min for 48 h. Thus, the permalloy was obtained. FIG. 11 is a micrograph illustrating permalloy viewed by a body-viewing microscope.

The heating fusion was performed using a pyrolysis technique to fully fuse the prepared permalloy with the magnetic composite material. The fusion was performed at a temperature of 100℃ for 12 h. FIG. 12 is a micrograph illustrating a magnetic composite material viewed by a body-viewing microscope. FIG. 13 is a diagram illustrating an insertion loss of a magnetic composite material.

Test Embodiment 6

The density, thermal conductivity, and wave-absorbing performance of the magnetic composite material obtained from Embodiments 18-19 were tested according to test Embodiment 1. The test results are shown in Table 6.

Table 6

Embodiment 20

Embodiment 20 was performed with reference to Embodiment 18, different from Embodiment 18, in the Embodiment 20, a mass ratio of Fe₃O₄ to ammonia was 2.5: 1. Fe₃O₄ in the magnetic composite material had a length of 20 nm in the X-axis direction and 20 nm in the Y-axis direction.

Embodiment 21

Embodiment 21 was performed with reference to Embodiment 19, different from Embodiment 19, in the Embodiment 21, a mass ratio of ferric nitrate nonahydrate to nickel nitrate hexahydrate was 1: 15. The permalloy in the magnetic composite material had a length of 16 nm in the X-axis direction and 17 nm in the Y-axis direction.

Embodiment 22

Embodiment 22 was performed with reference to Embodiment 20, different from Embodiment 20, in the Embodiment 22, the mass ratio of Fe₃O₄ to the magnetic composite material was 1: 1.65.

Embodiment 23

Embodiment 23 was performed with reference to Embodiment 21, different from Embodiment 21, in the Embodiment 23, the mass ratio of the permalloy to the magnetic composite material was 3: 1.0.

Embodiment 24

Embodiment 24 was performed with reference to Embodiment 23, different from Embodiment 23, in the operation of preparing the carbon crystal cluster of Embodiment 24, the ratio of the mass percent of hydrogen peroxide in the hydrogen peroxide solution to the mass percent of the first graphene oxide in the dispersion of the first graphene oxide was 1: 30. The edge length of one of the carbon crystals was 11.5 nm.

Embodiment 25

Embodiment 25 was performed with reference to Embodiment 23, different from Embodiment 23, in the operation of preparing the carbon crystal cluster of Embodiment 25, the ratio of the mass percent of hydrogen peroxide in the hydrogen peroxide solution to the mass percent of the first graphene oxide in the dispersion of the first graphene oxide was 1: 30. The edge length of one of the carbon crystals was 11.5 nm.

Embodiment 26

Embodiment 26 was performed with reference to Embodiment 24, different from Embodiment 24, in the operation of preparing the nano tungsten disulfide of Embodiment 26, the ratio of WCl₆ to thioacetamide was reduced to 1: 3, and the nano tungsten disulfide had a maximum diameter of 5 nm and an intermediate diameter of 4 nm.

Embodiment 27

Embodiment 27 was performed with reference to Embodiment 25, different from Embodiment 25, in the operation of preparing the nano tungsten disulfide of Embodiment 27, the ratio of WCl₆ to thioacetamide was reduced to 1: 3, and the nano tungsten disulfide had a maximum diameter of 5 nm and an intermediate diameter of 4 nm.

Embodiment 28

Embodiment 28 was performed with reference to Embodiment 26, different from Embodiment 26, in the operation of mixing the nano tungsten disulfide with the carbon crystal cluster of Embodiment 28, the mass ratio of the nano tungsten disulfide to the carbon crystal cluster was 1: 1.4.

Embodiment 29

Embodiment 29 was performed with reference to Embodiment 27, different from Embodiment 27, in the operation of mixing the nano tungsten disulfide with the carbon crystal cluster of Embodiment 29, the mass ratio of the nano tungsten disulfide to the carbon crystal cluster was 1: 1.4.

Test Embodiment 7

The density, thermal conductivity, and wave-absorbing performance of the magnetic composite material obtained in Embodiments 20-29 were tested as follows, and the results of the tests are shown in Table 7.

Table 7

Embodiment 30

10 g of iron was placed in a CO atmosphere and subjected to a high temperature and high pressure reaction at 210℃ and 1.5 MPa to obtain an oily substance. The oily substance was separated at a low pressure to obtain soft powder, which was then reduced with hydrogen. Finally, the soft powder was ground under a pressure of 0.7 MPa, a rotation speed of 150 rpm, and a grinding time of 12 h to obtain two-dimensional iron nanocarbonyl.

The prepared two-dimensional iron nanocarbonyl and the magnetic composite prepared in Embodiment 1 were added to a ferrous chloride solution in a mass ratio of 4: 1. The mixture was heated and stirred at 50℃ for 6 h, and then cooled in a reducing gas CO. The resulting mixture was separated to obtain the magnetic composite material. FIG. 14 is a micrograph illustrating a magnetic composite material. FIG. 15 is a diagram illustrating an insertion loss of a magnetic composite material.

Test Embodiment 8

The density, thermal conductivity, and wave-absorbing performance of the magnetic composite material obtained in Embodiment 30 were tested according to test Embodiment 1. The test results are shown in Table 8.

Table 8

Embodiment 31

Embodiment 31 was performed with reference to Embodiment 30, different from Embodiment 30, in Embodiment 31, the grinding pressure was 0.6 MPa, the rotation speed of grinding was 350 rpm, the grinding time was 12 h, and the two-dimensional iron nanocarbonyl in the magnetic composite material had a maximum diameter of 5 nm and an intermediate diameter of 4 nm.

Embodiment 32

Embodiment 32 was performed with reference to Embodiment 31, different from Embodiment 31, in Embodiment 32, a mass ratio of particles of the two-dimensional iron nanocarbonyl to the magnetic composite material was 4.25: 1.

Embodiment 33

Embodiment 33 was performed with reference to Embodiment 32, different from Embodiment 32, in the operation of preparing the carbon crystal cluster of Embodiment 33, the ratio of the mass percent of hydrogen peroxide in the hydrogen peroxide solution to the mass percent of the first graphene oxide in the dispersion of the first graphene oxide was 1: 30. The edge length of one of the carbon crystals was 11.5 nm.

Embodiment 34

Embodiment 34 was performed with reference to Embodiment 33, different from Embodiment 33, in the operation of preparing the nano tungsten disulfide of Embodiment 34, the ratio of WCl₆ to thioacetamide was reduced to 1: 3, and the nano tungsten disulfide had a maximum diameter of 5 nm and an intermediate diameter of 4 nm.

Embodiment 35

Embodiment 35 was performed with reference to Embodiment 34, different from Embodiment 34, in the operation of mixing the nano tungsten disulfide and the carbon crystal cluster of Embodiment 35, the mass ratio of the nano tungsten disulfide to the carbon crystal cluster was 1: 1.4.

Test Embodiment 9

The density, thermal conductivity, and wave-absorbing performance of the magnetic composite material obtained in embodiments 31-35 were tested with reference to test Embodiment 1, and the results of the tests are shown in Table 9.

Table 9

Embodiment 36

15 g of anhydrous copper chloride, 10.5 g of sodium phosphite, 3.3 g of polyvinylpyrrolidone, and 3.1 g of isopropanol were dissolved in 100 mL of a mixed solvent of diethylene glycol and octadecanethiol to obtain a mixed solution. The mass ratio of diethylene glycol to octadecanethiol was 1: 1.5. The mixed solution was reacted at 180℃ for 100 minutes. The reaction product was filtered, washed, and dried to obtain copper powder.

The prepared copper powder was mixed and ground with the magnetic composite material of Deo prepared in Embodiment 1 according to a mass ratio of 4.5: 1. The grinding pressure was 0.1 MPa, the grinding speed was 150 rpm, and the grinding time was 12 h. The magnetic composite material was then subjected to hydrogenation, heated at 50℃, and cooled in the inert gas to obtain the magnetic composite material. FIG. 16 is a micrograph illustrating a magnetic composite material. FIG. 17 is a diagram illustrating an insertion loss of a magnetic composite material.

Test Embodiment 10

The density, thermal conductivity, and wave-absorbing performance of the magnetic composite material obtained in Embodiment 36 were tested according to test Embodiment 1. The test results are shown in Table 10.

Table 10

Embodiment 37

Embodiment 37 was performed with reference to Embodiment 36, different from Embodiment 36, in Embodiment 37, the grinding pressure was 0.2 MPa, the grinding speed was 180 rpm, the grinding time was 13 h, and the length of the copper powder in the magnetic composite material was 3 nm in the X-axis direction, 3 nm in the Y-axis direction, and 3 nm in the Z-axis direction.

Embodiment 38

Embodiment 38 was performed with reference to Embodiment 37, different from Embodiment 37, in Embodiment 38, the mass ratio of copper powder to magnetic composite was 4.7: 1.1.

Embodiment 39

Embodiment 39 was performed with reference to Embodiment 37, different from Embodiment 37, in the operation of preparing the carbon crystal clusters of Embodiment 39, the ratio of the mass percent of hydrogen peroxide in the hydrogen peroxide solution to the mass percent of the first graphene oxide in the dispersion of the first graphene oxide was 1: 30. The edge length of one of the carbon crystals was 11.5 nm.

Embodiment 40

Embodiment 40 was performed with reference to Embodiment 39, different from Embodiment 39, in the operation of preparing the nano tungsten disulfide of Embodiment 40, the ratio of WCl₆ to thioacetamide was reduced to 1: 3, and the nano tungsten disulfide had a maximum diameter of 5 nm and an intermediate diameter of 4 nm.

Embodiment 41

Embodiment 41 was performed with reference to Embodiment 40, different from Embodiment 40, in the operation of mixing the nano tungsten disulfide and carbon crystal cluster of Embodiment 41, the mass ratio of the nano tungsten disulfide to the carbon crystal cluster was 1: 1.4.

Test Embodiment 11

The density, thermal conductivity, and wave-absorbing performance of the magnetic composite material obtained in Embodiments 37-41 were tested with reference to test Embodiment 1, and the results of the tests are shown in Table 11.

Table 11

Embodiment 42

The wave-absorbing gel was prepared using a single-component gel preparation manner, wherein vinyl silicone oil was mixed with an ethynyl cyclohexanol inhibitor according to a mass ratio of 8: 1, to obtain 20 g of the first mixture; 80 g of the magnetic composite material obtained in Embodiment 1 was added to the first mixture to obtain a second mixture; 30 g of hydrogen-containing silicone oil was added to the second mixture to obtain a third mixture; and 0.5 g of a chloroplatinic acid catalyst was added to the third mixture to perform a cross-linking reaction and obtain the wave-absorbing gel.

Comparative Embodiment 5

Comparative Embodiment 5 was performed with reference to Embodiment 42, different from Embodiment 42, in Comparative Embodiment 5, the magnetic composite material was replaced with ferrite magnetic powder. FIG. 18 is a diagram illustrating a comparison between an insertion loss of a cured wave-absorbing gel made according to Embodiment 42 and an insertion loss of a cured wave-absorbing gel made according to Embodiment 5.

Test Embodiment 12

The thermal conductivity, wave-absorbing performance, and compression modulus of the wave-absorbing gel obtained in Embodiment 42 and comparison Embodiment 5 were tested, wherein the test process of the thermal conductivity and wave-absorbing performance were performed with reference to test Embodiment 1, the test process of the compression modulus are shown as follows, and the test results are shown in Table 12.

Compression modulus: testing the compression modulus referring to GB/T2918.

Table 12

According to Table 12, the wave-absorbing gel prepared from the magnetic composite material of the present disclosure may have higher insertion loss compared to ferrite magnetic powders, and the absorption bandwidth may cover electromagnetic waves in the frequency band of 30 MHz-3.5 GHz.

Embodiment 43

Embodiment 43 was performed with reference to Embodiment 42, different from Embodiment 42, in Embodiment 43, the mass percent of the magnetic composite material in the wave-absorbing gel was 70%.

Embodiment 44

Embodiment 44 was performed with reference to Embodiment 43, different from Embodiment 43, in Embodiment 44, the wave-absorbing gel also included 10 g of iron powder with a permeability of 3.5 H/m.

Embodiment 45

Embodiment 45 was performed with reference to Embodiment 44, different from Embodiment 44, in the operation of preparing the carbon crystal cluster of Embodiment 45, a ratio of the mass percent of hydrogen peroxide in the hydrogen peroxide solution to the mass percent of the first graphene oxide in the dispersion of the first graphene oxide was 1: 30. The edge length of one of the carbon crystals was 11.5 nm.

Embodiment 46

Embodiment 46 was performed with reference to Embodiment 45, different from Embodiment 45, in the operation of preparing the nano tungsten disulfide of Embodiment 46, the ratio of WCl₆ to thioacetamide was reduced to 1: 3, and the nano tungsten disulfide had a maximum diameter of 5 nm and an intermediate diameter of 4 nm.

Embodiment 47

Embodiment 47 was performed with reference to Embodiment 46, different from Embodiment 46, in the operation of mixing the nano tungsten disulfide and the carbon crystal cluster of Embodiment 47, the mass ratio of the nano tungsten disulfide to the carbon crystal cluster was 1: 1.4.

Test Embodiment 13

The thermal conductivity, wave-absorbing performance, and compression modulus of the wave-absorbing gel in Embodiments 43-47 were tested. The testing process refers to test Embodiment 12, and the test results are shown in Table 13.

Table 13

Embodiment 48

The wave-absorbing composition was obtained by mixing 75 g of the magnetic composite material prepared in Embodiment 1 with 15 g of an acrylic adhesive.

A printed circuit board was provided. FIG. 19 is a radiometric far-field simulation diagram illustrating a printed circuit board. An insulating layer was first formed on the outer surface of the printed circuit board, and then the wave-absorbing composition was formed on the outer surface of the insulating layer. After curing at 3℃ for 0.5 h, a wave-absorbing layer was formed, and an electromagnetic shielding encapsulant was obtained. FIG. 20 is a radiometric far-field simulation diagram illustrating an electromagnetic shielding encapsulant.

Test embodiment 14

The wave-absorbing composition obtained in Embodiment 48 was calendered and cured to form a wave-absorbing layer with a thickness of 3 mm. The thermal conductivity and wave-absorbing performance of the wave-absorbing layer were tested. The test process refers to test Embodiment 1, and the test results are shown in Table 14.

Table 14

Embodiment 49

Embodiment 49 was performed with reference to Embodiment 48 different from Embodiment 48, in Embodiment 49, the mass percent of the magnetic composite material in the wave-absorbing composition was 75%.

Embodiment 50

Embodiment 50 was performed with reference to Embodiment 49 different from Embodiment 49, in Embodiment 50, the wave-absorbing composition further included 5 g of epoxy resin.

Embodiment 51

Embodiment 51 was performed with reference to Embodiment 49 different from Embodiment 49, in Embodiment 51, the acrylic adhesive was replaced with vinyl acetate resin.

Embodiment 52

Embodiment 52 was performed with reference to Embodiment 49 different from Embodiment 49, in Embodiment 52, in the operation of preparing the carbon crystal cluster, the ratio of the mass percent of hydrogen peroxide in the hydrogen peroxide solution to the mass percent of the first graphene oxide in the dispersion of the first graphene oxide was 1: 30. The edge length of one of the carbon crystals was 11.5 nm.

Embodiment 53

Embodiment 53 was performed with reference to Embodiment 52, different from Embodiment 52, in the operation of preparing the nano tungsten disulfide of Embodiment 53, the ratio of WCl₆ to thioacetamide was reduced to 1: 3, and the nano tungsten disulfide had a maximum diameter of 5 nm and an intermediate diameter of 4 nm.

Embodiment 54

Embodiment 54 was performed with reference to Embodiment 53, different from Embodiment 53, in the operation of mixing the nano tungsten disulfide and the carbon crystal cluster of Embodiment 54, the mass ratio of the nano tungsten disulfide to the carbon crystal cluster was 1: 1.4.

Test Embodiment 15

The wave-absorbing compositions obtained in Embodiments 49-54 were calendered and cured to form a wave-absorbing layer with a thickness of 3 mm. The thermal conductivity and wave-absorbing performance of the wave-absorbing layer were tested using the test process described in test Embodiment 1. The test results are shown in Table 15.

Table 15

Embodiment 55

The wave-absorbing composition was prepared by uniformly mixing the magnetic composite material prepared in Embodiment 1, epoxy resin, curing agent dicyandiamide, and solvent dimethylformamide in a stirring kettle at a mass ratio of 2.5: 5: 2: 1. The mass percent of the magnetic composite material in the wave-absorbing composition was 23.8%.

The above wave-absorbing composition was coated onto glass fiber cloth and cured in an oven at 150℃, resulting in a semi-cured sheet.

Copper foils were laminated on both sides of the semi-cured sheet, and the semi-cured sheet was placed in a vacuum hot press under a pressure of 4.8 MPa-5.0 MPa and a temperature of 190℃-210℃ for 2 h to cure and form a dielectric layer, thus obtaining the circuit substrate. The mass percent of the magnetic composite material in the dielectric layer was 26%.

The obtained circuit substrate was made into a printed circuit board. A radiometric far-field simulation of the printed circuit board is shown in FIG. 21.

Comparative Embodiment 6

Comparative Embodiment 6 was performed with reference to Embodiment 55, different from Embodiment 55, in Comparative Embodiment 6, the wave-absorbing composition did not include the magnetic composite material, as shown in FIG. 22, which shows a radiometric far-field simulation of the printed circuit board.

Test Embodiment 16

The wave-absorbing performance of the printed circuit board obtained in Embodiment 55 and comparative Embodiment 6 were tested according to the test process in test Embodiment 1, and the test results are shown in Table 16.

Table 16

According to Table 16, when the wave-absorbing composition includes the magnetic composite material prepared in the embodiments of the present disclosure, the insertion loss of the printed circuit board prepared based on the wave-absorbing composition may be greatly increased, and the wave-absorbing performance may be greatly improved.

Embodiment 56

Embodiment 56 was performed with reference to Embodiment 55, different from Embodiment 55, in the operation of preparing the carbon crystal cluster of Embodiment 56 , the ratio of the mass percent of hydrogen peroxide in the hydrogen peroxide solution to the mass percent of the first graphene oxide in the dispersion of the first graphene oxide was 1: 30. The edge length of one of the carbon crystals was 11.5 nm.

Embodiment 57

Embodiment 57 was performed with reference to Embodiment 56, different from Embodiment 56, in the operation of preparing the nano tungsten disulfide of Embodiment 57, the ratio of WCl₆ to thioacetamide was reduced to 1: 3, and the nano tungsten disulfide has a maximum diameter of 5 nm and an intermediate diameter of 4 nm.

Embodiment 58

Embodiment 58 was performed with reference to Embodiment 57, different from Embodiment 57, in the operation of mixing the nano tungsten disulfide and the carbon crystal cluster of Embodiment 58, the mass ratio of the nano tungsten disulfide to the carbon crystal cluster was 1: 1.4.

Embodiment 59

Embodiment 59 was performed with reference to Embodiment 58, different from Embodiment 58, in Embodiment 59, the wave-absorbing composition included 1, 1, 2, 2-tetrahydroxyphenyl ethane tetraglycidyl ether. The mass ratio of the epoxy resin to the 1, 1, 2, 2-tetrahydroxyphenyl ethane tetraglycidyl ether was 5: 0.5, and the fiberglass cloth was silanized.

Test Embodiment 17

The wave-absorbing performance of the printed circuit board obtained in Embodiments 56-59 were tested according to the test process according to test Embodiment 1, and the results of the tests are shown in Table 17.

Table 17

Embodiment 60

Arc discharge was performed using graphite as a cathode, a composite electrode including carbon and H₂O₂ as an anode, and hydrogen as a reactive gas in a reaction vessel filled with helium. The arc discharge was performed at a temperature of 3, 650℃, resulting in the formation of disordered single-walled carbon nanotubes.

The disordered single-walled carbon nanotubes were heated at 700℃ for 4.5 h and adhered to a template with Fe/CO adhered to a surface of the template. After cooling down to 300℃ for finalization, parallel-arranged carbon nanotubes were obtained.

A mixture containing 100 mL of toluene diisocyanate, 50 mL of ethylene glycol, 200 mL of polyester oligomers containing terminal hydroxyl groups, and 150 mL of polyformaldehyde resin was polymerized at 70℃ to obtain the soft polyurethane.

The magnetic composite material, carbon nanotubes, and soft polyurethane prepared in Embodiment 1 were added to a blender in a mass ratio of 2.5: 2: 1, stirred at 350 r/min for 24 h and then injected into a hollow cylindrical mold after thorough mixing. The surface temperature of the mold was controlled at -10℃. After curing and shaping, magnetic hollow tubes with wall thicknesses of 3 mm or 1.5 mm were obtained. FIG. 23 is a scanning electron micrograph illustrating a magnetic hollow tube made according to Embodiment 60, where A represents the carbon nanotube, B represents the magnetic composite material, and C represents the adhesive. FIG. 24 is a diagram illustrating an insertion loss of a magnetic hollow tube made according to Embodiment 60.

Comparative Embodiment 7

Comparative Embodiment 7 was performed with reference to Embodiment 60 (with a wall thickness of 1.5 mm) , different from Embodiment 60, in Comparative Embodiment 7, only the magnetic composite material and the adhesive were added to the blender, without adding the carbon nanotubes.

Comparative Embodiment 8

Comparative Embodiment 8 was performed with reference to embodiment 60 (with a wall thickness of 1.5 mm) , different from Embodiment 60, in Comparative Embodiment 8, only the carbon nanotubes and the adhesive were added to the blender, without adding the magnetic composite material.

Test Embodiment 18

The density, thermal conductivity, wave-absorbing performance, and the a of the magnetic hollow tubes obtained in Embodiment 60 and comparative Embodiments 7-8, with the testing process of density, thermal conductivity, and wave-absorbing performance referring to test Embodiment 1, and a testing process of the ductility range is as follows. The testing results are shown in Table 18.

Ductility range test includes: measuring the flexibility of the material referring to ASTM F147-1987 (2017) .

Table 18

As shown in Table 8, carbon nanotubes may further improve the wave-absorbing performance of magnetic composite material in specific frequency bands.

Embodiment 61

Embodiment 61 was performed with reference to Embodiment 60 (with a wall thickness of 1.5 mm) , different from Embodiment 60, in Embodiment 61, the adhesive was selected from the epoxy resin.

Embodiment 62

Embodiment 62 was performed with reference to Embodiment 60 (with a wall thickness of 1.5 mm) , different from Embodiment 60, in Embodiment 62, the disordered single-walled carbon nanotubes were heated at 700℃ for 4 h. The tube diameter of the carbon nanotubes was 20 nm. Embodiment 63

Embodiment 63 was performed with reference to Embodiment 62, different from Embodiment 62, in the operation of adding the magnetic composite material of Embodiment 63, carbon nanotubes, and adhesive to the blender, the mass ratio of the carbon nanotubes to the magnetic composite material was 1.33: 1.

Embodiment 64

Embodiment 64 was performed with reference to Embodiment 63, different from Embodiment 63, in the operation of adding the magnetic composite material, carbon nanotubes, and adhesive to the blender of Embodiment 64, the mass ratio of the carbon nanotubes to the adhesive was 1.5: 1.

Embodiment 65

Embodiment 65 was performed with reference to Embodiment 63, different from Embodiment 63, in the operation of preparing the carbon crystal cluster of Embodiment 65, the ratio of the mass percent of hydrogen peroxide in the hydrogen peroxide solution to the mass percent of the first graphene oxide in the dispersion of the first graphene oxide was 1: 30. The edge length of one of the carbon crystals was 11.5 nm.

Embodiment 66

Embodiment 66 was performed with reference to Embodiment 65, different from Embodiment 65, in the operation of preparing the nano tungsten disulfide of Embodiment 66, the ratio of WCl₆ to thioacetamide was reduced to 1: 3, and the nano tungsten disulfide had a maximum diameter of 5 nm and an intermediate diameter of 4 nm.

Embodiment 67

Embodiment 67 was performed with reference to Embodiment 66, different from Embodiment 66, in the operation of mixing the nano tungsten disulfide and the carbon crystal cluster of Embodiment 67, the mass ratio of the nano tungsten disulfide to carbon crystal cluster was 1: 1.4. Test Embodiment 19

The density, thermal conductivity, wave-absorbing performance, and ductility range of magnetic hollow tubes obtained in Embodiments 61-67 were tested with reference to test Embodiment 18, and the testing process of ductility range is as follows. The test results are shown in Table 19.

Table 19

Embodiment 68

Graphene powder was added to water in a mass ratio of 1: 3 for mixing, then SnCl₂ was added. The mass ratio of SnCl₂ to the graphene powder was 1: 1. The mixture was then placed in the argon gas atmosphere and heated at 250℃ for 6 h, and then cooled in the CO environment to obtain the first formulation.

The first formulation was mixed with phenolic resin to obtain the second formulation. The mass ratio of the graphene powder to the phenolic resin was 5: 1.

The second formulation was added to poly (methyl vinyl acid ethyl ester) colloid crystals. A mass ratio of graphene to poly (methyl vinyl acid ethyl ester) colloid crystals was 8: 1. The mixture was then placed in the argon gas atmosphere and heated at a temperature of 200℃ for 24 h, then cooled in the CO environment to obtain the graphene cluster shown in FIG. 25. The graphene cluster consisted of porous graphene ellipsoids arranged in a three-dimensional array. One of the porous graphene ellipsoids had an equatorial radius of 100 nm, a polar radius of 210 nm, and a pore diameter of 18 nm.

The graphene cluster and the nano zinc sulfide with a particle size of 1.8 nm were added to water in a mass ratio of 4: 1 to be stirred and mixed, then ethylene oxide and propylene oxide block copolyether were added. The mixture was then placed in the argon gas atmosphere and heated to a viscous consistency at 150℃, and finally cooled to obtain the magnetic composite material shown in FIG. 26.

Embodiment 69

Embodiment 69 was performed with reference to Embodiment 68, different from Embodiment 68, in Embodiment 69, the mass ratio of graphene cluster to the nano zinc sulfide was 5: 1.

Embodiment 70

Embodiment 70 was performed with reference to Embodiment 68, different from Embodiment 68, in Embodiment 70, the mass ratio of the graphene cluster to the nano zinc sulfide was 3: 1.

Embodiment 71

Embodiment 71 was performed with reference to Embodiment 68, different from Embodiment 68, in Embodiment 71, the second formulation was added to the poly (methyl vinyl acid ethyl ester) colloid crystals, and heated at a temperature of 180℃ for 24 h. The resulting porous graphene ellipsoid had an equatorial radius of 100 nm, a polar radius of 200 nm, and a pore diameter of 14 nm. The particle size of the nano zinc sulfide was 1.7 nm.

Embodiment 72

Embodiment 72 was performed with reference to Embodiment 68, different from Embodiment 68, in Embodiment 72, the second formulation was added to the poly (methyl vinyl acid ethyl ester) colloid crystals, and heated at a temperature of 220℃ for 22 h. The resulting porous graphene ellipsoid had an equatorial radius of 110 nm, a polar radius of 210 nm, and a pore diameter of 17 nm. The particle size of the nano zinc sulfide was 1.7 nm.

Embodiment 73

Embodiment 73 was performed with reference to Embodiment 68, different from Embodiment 68, in Embodiment 73, the second formulation was added to the poly (methyl vinyl acid ethyl ester) colloid crystals, and heated at a temperature of 220℃ for 24 h. The resulting porous graphene ellipsoid had an equatorial radius of 120 nm, a polar radius of 220 nm, and a pore diameter of 22 nm. The particle size of the nano zinc sulfide was 2 nm.

Comparative Embodiment 9

Comparative experiment 9 was performed with reference to Embodiment 68, different from Embodiment 68, in Comparative Embodiment 9, the second formulation was added to the poly (methyl vinyl acid ethyl ester) colloid crystals, and heated at a temperature of 150℃ for 24 h, resulting in a graphene cluster composed of a three-dimensional arrangement of spherical graphene.

Comparative Embodiment 10

Comparative Embodiment 10 was performed with reference to Embodiment 68, different from Embodiment 68, in Comparative Embodiment 10, the second formulation was added to the poly (methyl vinyl acid ethyl ester) colloid crystals, and heated at a temperature of 190℃ for 18 h to obtain a graphene cluster composed of a three-dimensional arrangement of rod graphene.

Comparative Embodiment 11

Comparative Embodiment 11 was performed with reference to Embodiment 68, different from Embodiment 68, in Comparative Embodiment 11, carbon nanotubes were used instead of graphene to obtain a cluster of carbon nanotubes composed of a three-dimensional arrangement of porous carbon nanotube ellipsoids.

Test Embodiment 20

The wave absorption performance of the magnetic composite material obtained in Embodiments 68-73 and comparative Embodiments 9-11 were tested using the following process, and the test results are shown in Table 20.

Wave-absorbing performance test includes: testing an absorption bandwidth and an insertion loss referring to GB/T32596.

Table 20

As shown in Table 20, when the graphene cluster was prepared based on a colloid crystal templating technique using the poly (methyl vinyl acid ethyl ester) as a colloid crystal template by heating at a temperature of 180℃-220℃ for 20-28 h, the prepared magnetic composite material may cover an absorption bandwidth of 0.02-1.2 GHz.

Embodiment 74

Embodiment 74 was performed with reference to Embodiment 68, different from Embodiment 68, in the operation of adding the graphene cluster and the nano zinc sulfide to the water of Embodiment 74, a hard magnetic ferrite nanomaterial was also added. The hard magnetic ferrite nanomaterial had a particle size of 6 nm, the mass ratio of the graphene cluster to the hard magnetic ferrite nanomaterial was 5: 1.

Embodiment 75

Embodiment 75 was performed with reference to Embodiment 74, different from Embodiment 74, in Embodiment 75, the particle size of the hard magnetic ferrite nanomaterial was 7 nm.

Embodiment 76

Embodiment 76 was performed with reference to Embodiment 74, different from Embodiment 74, in Embodiment 76, the particle size of the hard magnetic ferrite nanomaterial was 8 nm.

Embodiment 77

Embodiment 77 was performed with reference to Embodiment 74, different from Embodiment 74, in Embodiment 77, the mass ratio of the graphene cluster to the hard magnetic ferrite nanomaterial was 8: 1.

Embodiment 78

Embodiment 78 was performed with reference to Embodiment 74, different from Embodiment 74, in Embodiment 78, the mass ratio of the graphene cluster to the hard magnetic ferrite nanomaterial was 6: 1.

Embodiment 79

Embodiment 79 was performed with reference to Embodiment 74, different from Embodiment 74, in Embodiment 79, the mass ratio of the graphene cluster to the hard magnetic ferrite nanomaterial was 4: 1.

Comparative Embodiment 12

Comparative Embodiment 12 was performed with reference to Comparative Embodiment 9, different from Comparative Embodiment 9, in the operation of adding the graphene cluster and the nano zinc sulfide to the water of Comparative Embodiment 12, a hard magnetic ferrite nanomaterial was also added. The hard magnetic ferrite nanomaterial had a particle size of 6 nm, and the mass ratio of the graphene cluster to the hard magnetic ferrite nanomaterial was 5: 1.

Comparative Embodiment 13

Comparative Embodiment 13 was performed with reference to comparative embodiment 10, different from Comparative Embodiment 10, in the operation of adding the graphene cluster and the nano zinc sulfide to the water of Comparative Embodiment 13, the hard magnetic ferrite nanomaterial was also added. The hard magnetic ferrite nanomaterial had a particle size of 6 nm, and the mass ratio of the graphene cluster to the hard magnetic ferrite nanomaterial was 5: 1.

Comparative Embodiment 14

Comparative Embodiment 14 was performed with reference to comparative Embodiment 11, different from Comparative Embodiment 11, in the operation of adding the carbon nanotube cluster with nano zinc sulfide to the water of Comparative Embodiment 14, the hard magnetic ferrite nanomaterial was also added, the hard magnetic ferrite nanomaterial had a particle size of 6 nm, and the mass ratio of the graphene cluster to the hard magnetic ferrite nanomaterial was 5: 1.

Test Embodiment 21

The wave-absorbing performance of the magnetic composite material obtained from Embodiments 74-79 and comparative Embodiments 12-14 were tested with reference to Test Embodiment 20, and the results of the tests are shown in Table 21.

Table 21

According to Table 21, it may be seen that when a hard magnetic ferrite nanomaterial is further included in the magnetic composite material, and the graphene cluster is prepared based on a colloid crystal templating technique using the poly (methyl vinyl acid ethyl ester) as a colloid crystal template by heating at a temperature of 180℃-220℃ for 20-28 h, the prepared magnetic composite material may cover an absorption bandwidth of 13 MHz-20 MHz. At the same time, the prepared magnetic composite material may have a high magnetic permeability. However, when the reaction temperature of the preparation of the graphene cluster is below 180℃ and the reaction time is below 20 h, or when carbon nanotubes are used instead of graphene, the prepared magnetic composite material may do not have a polymagnetic function, and the absorption bandwidth may change to 1000 MHz-14000 MHz.

Embodiment 80

Embodiment 80 was performed with reference to Embodiment 68, different from Embodiment 68, in the operation of adding the graphene cluster and the nano zinc sulfide to the water of Embodiment 80, spherical nanosilver was also added with a particle size of 5 nm, and a mass ratio of the graphene cluster to the spherical nanosilver was 4: 1.

Embodiment 81

Embodiment 81 was performed with reference to Embodiment 80, different from Embodiment 80, in Embodiment 81, the particle size of the spherical nanosilver was 6 nm.

Embodiment 82

Embodiment 82 was performed with reference to Embodiment 80, different from Embodiment 80, in Embodiment 82, the particle size of the spherical nanosilver was 7 nm.

Embodiment 83

Embodiment 83 was performed with reference to Embodiment 80, different from Embodiment 80, in Embodiment 83, the mass ratio of the graphene cluster to the spherical nanosilver was 5: 1.

Embodiment 84

Embodiment 84 was performed with reference to Embodiment 80, different from Embodiment 80, in Embodiment 84, the mass ratio of the graphene cluster to the spherical nanosilver was 3: 1.

Comparative Embodiment 15

Comparative Embodiment 15 was performed with reference to Comparative Embodiment 9, different from Comparative Embodiment 9, in the operation of adding the graphene cluster and the nano zinc sulfide to the water of Comparative Embodiment 15, the spherical nanosilver was also added with a particle size of 5 nm, and the mass ratio of the graphene cluster to the spherical nanosilver was 4: 1.

Comparative Embodiment 16

Comparative Embodiment 16 was performed with reference to comparative Embodiment 10, different from Comparative Embodiment 10, in the operation of adding the graphene cluster and the nano zinc sulfide to the water of Comparative Embodiment 16, the spherical nanosilver was also added with a particle size of 5 nm, and the mass ratio of the graphene cluster to the spherical nanosilver was 4: 1.

Comparative Embodiment 17

Comparative Embodiment 17 was performed with reference to Comparative Embodiment 11, different from Comparative Embodiment 11, in the operation of adding the carbon nanotube cluster and the nano zinc sulfide to the water of Comparative Embodiment 17, the spherical nanosilver was also added with a particle size of 5 nm, and the mass ratio of the graphene cluster to the spherical nanosilver was 4: 1.

Test Embodiment 22

The wave-absorbing performance of the magnetic composite material obtained in Embodiments 80-84 and Comparative Embodiments 15-17 were tested with reference to Test Embodiment 20, and the test results are shown in Table 22.

Table 22

As shown in Table 22, when the spherical nanosilver is further included in the magnetic composite material, and the graphene cluster is prepared based on a colloid crystal templating technique using the poly (methyl vinyl acid ethyl ester) as a colloid crystal template by heating at a temperature of 180℃-220℃ for 20-28 h, the absorption bandwidth of the prepared magnetic composite material may change to a frequency band of 13 MHz-20 MHz, and the insertion loss may increase to about 40 dB. When the reaction temperature of the preparation of the graphene cluster is below 180℃ and the reaction time is below 20 h, or when carbon nanotubes are used instead of graphene, the prepared magnetic composite material may have a lower insertion loss and poorer wave-absorbing performance.

Embodiment 85

Embodiment 85 was performed with reference to Embodiment 68, different from Embodiment 68, in the operation of adding the graphene cluster with the nano zinc sulfide to the water of Embodiment 85, a ferrochromium cobalt alloy nanomaterial was also added. A particle size of the ferrochromium cobalt alloy nanomaterial was 8 nm, and a mass ratio of the graphene cluster to the ferrochromium cobalt alloy nanomaterial was 5: 1.

Embodiment 86

Embodiment 86 was performed with reference to Embodiment 85, different from Embodiment 85, in Embodiment 86, the particle size of the ferrochromium cobalt alloy nanomaterial was 9 nm.

Embodiment 87

Embodiment 87 was performed with reference to Embodiment 85, different from Embodiment 85, in Embodiment 87, the particle size of the ferrochromium cobalt alloy nanomaterial was 10 nm.

Embodiment 88

Embodiment 88 was performed with reference to Embodiment 85, different from Embodiment 85, in Embodiment 88, the mass ratio of the graphene cluster to the ferrochromium cobalt alloy nanomaterial was 7: 1.

Embodiment 89

Embodiment 89 was performed with reference to Embodiment 85, different from Embodiment 85, in Embodiment 89, the mass ratio of the graphene cluster to the ferrochromium cobalt alloy nanomaterial was 4: 1.

Comparative Embodiment 18

Comparative Embodiment 18 was performed with reference to Comparative Embodiment 9, different from Comparative Embodiment 9, in the operation of adding the graphene cluster with the nano zinc sulfide to water of Comparative Embodiment 18, the ferrochromium cobalt alloy nanomaterial was also added. The particle size of the ferrochromium cobalt alloy nanomaterial was 8 nm, and the mass ratio of the graphene cluster to the ferrochromium cobalt alloy nanomaterial was 5: 1.

Comparative Embodiment 19

Comparative Embodiment 19 was performed with reference to comparative Embodiment 10, different from Comparative Embodiment 10, in the operation of adding the graphene cluster with the nano zinc sulfide to water of Comparative Embodiment 19, the ferrochromium cobalt alloy nanomaterial was also added. The particle size of the ferrochromium cobalt alloy nanomaterial was 8 nm, and the mass ratio of the graphene cluster to the ferrochromium cobalt alloy nanomaterial was 5: 1.

Comparative Embodiment 20

Comparative Embodiment 20 was performed with reference to Comparative Embodiment 11, different from Comparative Embodiment 11, in the operation of adding the carbon nanotube cluster with the nano zinc sulfide to the water of Comparative Embodiment 20, the ferrochromium cobalt alloy nanomaterial was also added. The particle size of the ferrochromium cobalt alloy nanomaterial was 8 nm, and the mass ratio of the graphene cluster to the ferrochromium cobalt alloy nanomaterial was 5: 1.

Test Embodiment 23

The wave-absorbing performance of the magnetic composite material obtained from Embodiments 85-89 and Comparative Embodiments 18-20 were tested with reference to Test Embodiment 20, and the results of the tests are shown in Table 23.

Table 23

According to Table 23, it may be seen that when the ferrochromium cobalt alloy nanomaterial was further included in the magnetic composite material, and the graphene cluster was prepared based on a colloid crystal templating technique using the poly (methyl vinyl acid ethyl ester) as a colloid crystal template by heating at a temperature in a range of 180℃-220℃ for 20-28 h, the absorption bandwidth of the prepared magnetic composite material may change to a frequency band of 5 GHz-6.4 GHz, and the insertion loss may increase to about 40 dB. Specially, in a frequency of 5.8 GHz, the insertion loss of electromagnetic waves may increase to about 45 dB. When the reaction temperature of the preparation of the graphene cluster is below 180℃ and the reaction time is below 20 h, or when carbon nanotubes are used instead of graphene, the prepared magnetic composite material may have an undetectable insertion loss and poorer wave-absorbing performance.

Embodiment 90

Embodiment 90 was performed with reference to Embodiment 68, different from Embodiment 68, in the operation of adding the graphene cluster and the nano zinc sulfide to the water of Embodiment 90, a platinum cobalt alloy nanomaterial was also added. A particle size of the platinum cobalt alloy nanomaterial was 10 nm, and a mass ratio of the graphene cluster to the platinum cobalt alloy nanomaterial was 5: 1.

Embodiment 91

Embodiment 91 was performed with reference to Embodiment 90, different from Embodiment 90, in Embodiment 91, the particle size of the platinum cobalt alloy nanomaterial was 11 nm.

Embodiment 92

Embodiment 92 was performed with reference to Embodiment 90, different from Embodiment 90, in Embodiment 92, the particle size of the platinum cobalt alloy nanomaterial was 12 nm.

Embodiment 93

Embodiment 93 was performed with reference to Embodiment 90, different from Embodiment 90, in Embodiment 93, the mass ratio of the graphene cluster to the platinum cobalt alloy nanomaterial was 7: 1.

Embodiment 94

Embodiment 94 was performed with reference to Embodiment 90, different from Embodiment 90, in Embodiment 94, the mass ratio of the graphene cluster to the platinum cobalt alloy nanomaterial was 4: 1.

Comparative Embodiment 21

Comparative Embodiment 21 was performed with reference to Comparative Embodiment 9, different from Comparative Embodiment 9, in the operation of adding the carbon nanotube cluster with the nano zinc sulfide to the water of Comparative Embodiment 21, the platinum cobalt alloy nanomaterial was also added. The particle size of the platinum cobalt alloy nanomaterial was 10 nm, and the mass ratio of the graphene cluster to the platinum cobalt alloy nanomaterial was 5: 1.

Comparative Embodiment 22

Comparative Embodiment 22 was performed with reference to Comparative Embodiment 10, different from Comparative Embodiment 10, in the operation of adding the carbon nanotube cluster with the nano zinc sulfide to the water of Comparative Embodiment 22, the platinum cobalt alloy nanomaterial was also added. The particle size of the platinum cobalt alloy nanomaterial was 10 nm, and the mass ratio of the graphene cluster to the platinum cobalt alloy nanomaterial was 5: 1.

Comparative Embodiment 23

Comparative Embodiment 21 was performed with reference to comparative Embodiment 9, different from Comparative Embodiment 9, in the operation of adding the carbon nanotube cluster with the nano zinc sulfide to the water of Comparative Embodiment 23, the platinum cobalt alloy nanomaterial was also added. The particle size of the platinum cobalt alloy nanomaterial was 10 nm, and the mass ratio of the graphene cluster to the platinum cobalt alloy nanomaterial was 5: 1.

Test Embodiment 24

The wave-absorbing performance of the magnetic composite material obtained from Embodiments 90-94 and Comparative Embodiments 21-23 were tested with reference to Test Embodiment 20, and the results of the tests are shown in Table 24.

Table 24

As shown in Table 24, when the platinum cobalt alloy nanomaterial is further included in the magnetic composite material, and the graphene cluster is prepared based on a colloid crystal templating technique using the poly (methyl vinyl acid ethyl ester) as a colloid crystal template by heating at a temperature in a range of 180℃-220℃ for 20-28 h, the prepared magnetic composite material may well absorb electromagnetic waves in a frequency band of 10 GHz-27 GHz and solve a problem of radiation spuriousness. When the reaction temperature of the preparation of the graphene cluster is below 180℃ and the reaction time is below 20 h, or when carbon nanotubes are used instead of graphene, the prepared magnetic composite material may have a narrow absorption bandwidth and poorer wave-absorbing performance.

Embodiment 95

Embodiment 95 was performed with reference to Embodiment 68, different from Embodiment 68, in the operation of adding the graphene cluster with the nano zinc sulfide to the water of Embodiment 95, the ferronickel alloy nanomaterial was also added, a particle size of the ferronickel alloy nanomaterial was 12 nm, and a mass ratio of the graphene cluster to the ferronickel alloy nanomaterial was 5: 1.

Embodiment 96

Embodiment 96 was performed with reference to Embodiment 95, different from Embodiment 95, in Embodiment 96, the particle size of the ferronickel alloy nanomaterial was 13 nm.

Embodiment 97

Embodiment 97 was performed with reference to Embodiment 95, different from Embodiment 95, in Embodiment 97, the mass ratio of the graphene cluster to the ferronickel alloy nanomaterial was 7: 1.

Embodiment 98

Embodiment 98 was performed with reference to Embodiment 95, different from Embodiment 95, in Embodiment 98, the mass ratio of the graphene cluster to the ferronickel alloy nanomaterial was 3: 1.

Comparative Embodiment 24

Comparative Embodiment 24 was performed with reference to Comparative Embodiment 9, different from Comparative Embodiment 9, in the operation of adding the graphene cluster and the nano zinc sulfide to the water of Comparative Embodiment 24, the ferronickel alloy nanomaterial was also added. The particle size of the ferronickel alloy nanomaterial was 12 nm, and the mass ratio of the graphene cluster to the ferronickel alloy nanomaterial was 5: 1.

Comparative Embodiment 25

Comparative Embodiment 25 was performed with reference to Comparative Embodiment 10, different from Comparative Embodiment 10, in the operation of adding the graphene cluster and the nano zinc sulfide to the water of Comparative Embodiment 25, the ferronickel alloy nanomaterial was also added. The particle size of the ferronickel alloy nanomaterial was 12 nm, and the mass ratio of the graphene cluster to the ferronickel alloy nanomaterial was 5: 1.

Comparative Embodiment 26

Comparative Embodiment 26 was performed with reference to Comparative Embodiment 11, different from Comparative Embodiment 11, in the operation of adding the graphene cluster and the nano zinc sulfide to the water of Comparative Embodiment 26, the ferronickel alloy nanomaterial was also added. The particle size of the ferronickel alloy nanomaterial was 12 nm, and the mass ratio of the graphene cluster to the ferronickel alloy nanomaterial was 5: 1.

Test Embodiment 25

The wave-absorbing performance of the magnetic composite material obtained from Embodiments 95-98 and Comparative Embodiments 24-26 were tested with reference to Test Embodiment 1, and the results of the tests are shown in Table 25.

Table 25

As shown in Table 25, when the ferronickel alloy nanomaterial is further included in the magnetic composite material, and the graphene cluster is prepared based on a colloid crystal templating technique using the poly (methyl vinyl acid ethyl ester) as a colloid crystal template by heating at a temperature in a range of 180℃-220℃ for 20-28 h, the prepared magnetic composite material may well absorb electromagnetic waves in a frequency band of 40 GHz-60 GHz and improve the electromagnetic compatibility of electronic devices in resisting radar wave interference, such as shielding radar wave interference generated by automobile electronics and improving the electromagnetic compatibility between the automobile electronics and peripheral electronic devices. When the reaction temperature of the preparation of the graphene cluster is below 180℃ and the reaction time is below 20 h, or when carbon nanotubes are used instead of graphene, the prepared magnetic composite material may have a narrow absorption bandwidth and poorer wave-absorbing performance.

Embodiment 99

Embodiment 99 was performed with reference to Embodiment 68, different from Embodiment 68, in the operation of adding the graphene cluster with the nano zinc sulfide to the water of Embodiment 99, a porous silicon carbide nanomaterial was also added. A particle size of the porous silicon carbide nanomaterial was 13 nm, and a mass ratio of the graphene cluster to the porous silicon carbide nanomaterial was 6: 1.

Embodiment 100

Embodiment 100 was performed with reference to Embodiment 99, different from Embodiment 99, in Embodiment 100, the particle size of the porous silicon carbide nanomaterial was 14 nm.

Embodiment 101

Embodiment 101 was performed with reference to Embodiment 99, different from Embodiment 99, in Embodiment 101, the particle size of the porous silicon carbide nanomaterial was 15 nm.

Embodiment 102

Embodiment 102 was performed with reference to Embodiment 99, different from Embodiment 99, in Embodiment 102, the mass ratio of the graphene cluster to the porous silicon carbide nanomaterial was 8: 1.

Embodiment 103

Embodiment 103 was performed with reference to Embodiment 99, different from Embodiment 99, in Embodiment 103, the mass ratio of the graphene cluster to the porous silicon carbide nanomaterial was 4: 1.

Comparative Embodiment 27

Comparative Embodiment 27 was performed with reference to Comparative Embodiment 9, different from Comparative Embodiment 9, in the operation of adding the graphene cluster and the nano zinc sulfide to the water of Comparative Embodiment 27, the porous silicon carbide nanomaterial was also added, the particle size of the porous silicon carbide nanomaterial was 13 nm, and the mass ratio of the graphene cluster to the porous silicon carbide nanomaterial was 6: 1. Comparative Embodiment 28

Comparative Embodiment 28 was performed with reference to Comparative Embodiment 10, different from Comparative Embodiment 10, in the operation of adding the graphene cluster and the nano zinc sulfide to the water of Comparative Embodiment 28, the porous silicon carbide nanomaterial was also added, the particle size of the porous silicon carbide nanomaterial was 13 nm, and the mass ratio of the graphene cluster to the porous silicon carbide nanomaterial was 6: 1. Comparative Embodiment 29

Comparative Embodiment 29 was performed with reference to Comparative Embodiment 11, different from Comparative Embodiment 11, in the operation of adding the graphene cluster and the nano zinc sulfide to the water of Comparative Embodiment 29, the porous silicon carbide nanomaterial was also added, the particle size of the porous silicon carbide nanomaterial was 13 nm, and the mass ratio of the graphene cluster to the porous silicon carbide nanomaterial was 6: 1.

Test Embodiment 26

The wave-absorbing performance of the magnetic composite material obtained from Embodiments 99-103 and comparative Embodiments 27-29 were tested with reference to Test Embodiment 1, and the results of the tests are shown in Table 26.

Table 26.

As shown in Table 26, when the porous silicon carbide nanomaterial was further included in the magnetic composite material, and the graphene cluster was prepared based on a colloid crystal templating technique using the poly (methyl vinyl acid ethyl ester) as a colloid crystal template by heating at a temperature in a range of 180℃-220℃ for 20-28 h, the prepared magnetic composite material may well absorb millimeter radar in a frequency band of 70 GHz-85 GHz and improve the issue of electronic devices carrying millimeter wave. When the reaction temperature of the preparation of the graphene cluster is below 180℃ and the reaction time is below 20 h, or when carbon nanotubes are used instead of graphene, the prepared magnetic composite material may have an undetectable insertion loss and poorer wave-absorbing performance.

Each technical feature of the above-described embodiments can be combined in any way. In order to simplify the description, all possible combinations of each technical feature in the above-described embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope of the present disclosure.

The above-described embodiments only express several embodiments of the present disclosure, and their descriptions are relatively specific and detailed, but cannot be understood as limiting the scope of the invention patent. It should be noted that, for those skilled in the art, one or more modifications and improvements can be made without departing from the concept of the present disclosure, and these all belong to the protection scope of the present disclosure. Therefore, the scope of protection of the patent of the present invention should be determined by the appended claims.

Having thus described the basic concepts, it may be rather apparent to those skilled in the art after reading this detailed disclosure that the foregoing detailed disclosure is intended to be presented by way of example only and is not limiting. Various alterations, improvements, and modifications may occur and are intended to those skilled in the art, though not expressly stated herein. These alterations, improvements, and modifications are intended to be suggested by this disclosure and are within the spirit and scope of the exemplary embodiments of this disclosure.

Moreover, certain terminology has been used to describe embodiments of the present disclosure. For example, the terms “one embodiment, ” “an embodiment, ” and “some embodiments” mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Therefore, it is emphasized and should be appreciated that two or more references to “an embodiment” or “one embodiment” or “an alternative embodiment” in various portions of this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined as suitable in one or more embodiments of the present disclosure.

Furthermore, the recited order of processing elements or sequences, or the use of numbers, letters, or other designations therefore, is not intended to limit the claimed processes and methods to any order except as may be specified in the claims. Although the above disclosure discusses through various examples what is currently considered to be a variety of useful embodiments of the disclosure, it is to be understood that such detail is solely for that purpose and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover modifications and equivalent arrangements that are within the spirit and scope of the disclosed embodiments. For example, although the implementation of various components described above may be embodied in a hardware device, it may also be implemented as a software only solution, e.g., an installation on an existing server or mobile device.

Similarly, it should be appreciated that in the foregoing description of embodiments of the present disclosure, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the various embodiments. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed subject matter requires more features than are expressly recited in each claim. Rather, claimed subject matter may lie in less than all features of a single foregoing disclosed embodiment.

In some embodiments, numbers describing the number of ingredients and attributes are used. It should be understood that such numbers used for the description of the embodiments use the modifier "about" , "approximately" , or "substantially" in some examples. Unless otherwise stated, "about" , "approximately" , or "substantially" indicates that the number is allowed to vary by ±20%. Correspondingly, in some embodiments, the numerical parameters used in the description and claims are approximate values, and the approximate values may be changed according to the required characteristics of individual embodiments. In some embodiments, the numerical parameters should consider the prescribed effective digits and adopt the method of general digit retention. Although the numerical ranges and parameters used to confirm the breadth of the range in some embodiments of the present disclosure are approximate values, in specific embodiments, settings of such numerical values are as accurate as possible within a feasible range.

For each patent, patent application, patent application publication, or other materials cited in the present disclosure, such as articles, books, specifications, publications, documents, or the like, the entire contents of which are hereby incorporated into the present disclosure as a reference. The application history documents that are inconsistent or conflict with the content of the present disclosure are excluded, and the documents that restrict the broadest scope of the claims of the present disclosure (currently or later attached to the present disclosure) are also excluded. It should be noted that if there is any inconsistency or conflict between the description, definition, and/or use of terms in the adjuvant materials of the present disclosure and the content of the present disclosure, the description, definition, and/or use of terms in the present disclosure is subject to the present disclosure.

Finally, it should be understood that the embodiments described in the present disclosure are only used to illustrate the principles of the embodiments of the present disclosure. Other variations may also fall within the scope of the present disclosure. Therefore, as an example and not a limitation, alternative configurations of the embodiments of the present disclosure may be regarded as consistent with the teaching of the present disclosure. Accordingly, the embodiments of the present disclosure are not limited to the embodiments introduced and described in the present disclosure explicitly.

Claims

A magnetic composite material, comprising a carbon nanomaterial cluster and nano metal sulfide, the carbon nanomaterial cluster including a plurality of carbon nanomaterial units, wherein

the nano metal sulfide is mixed into the carbon nanomaterial cluster; and

the nano metal sulfide includes nano tungsten disulfide and/or nano zinc sulfide, and one of the plurality of carbon nanomaterial units includes nano carbon crystal and/or nano graphene.
The magnetic composite material of claim 1, wherein

the carbon nanomaterial cluster is a nano carbon crystal cluster comprising a plurality of the nano carbon crystals, and the nano metal sulfide is the nano tungsten disulfide, wherein

the nano tungsten disulfide is adhered to a surface of each of at least a portion of the plurality of the nano carbon crystals, and at least a portion of interstices of the nano carbon crystal cluster is filled with the nano tungsten disulfide.
The magnetic composite material of claim 2, wherein the nano tungsten disulfide is in the form of a cube and has a maximum diameter in a range of 3 nm-6 nm and an intermediate mid diameter in a range of 2 nm-5 nm.
The magnetic composite material of claim 2, wherein one of the plurality of the nano carbon crystals has a pore channel structure.
The magnetic composite material of claim 3, wherein one of the plurality of the nano carbon crystals is in the form of three-dimensional pyramid, and a ratio of the maximum diameter of the nano tungsten disulfide to an edge length of the nano carbon crystal is in a range of 1: 1.8-1: 3.
The magnetic composite material of claim 2, wherein a mass ratio of the nano tungsten disulfide to the cluster of nano carbon crystals is in a range of 1: 1.3-1: 1.5.
The magnetic composite material of claim 2, wherein the magnetic composite material further comprises one or more thermal conductive particles and/or a nanomagnetic material, the one or more thermal conductive particles and/or the nanomagnetic material is adhered to the surface of each of at least a portion of the nano carbon crystals and at least a portion of a surface of the nano tungsten disulfide, and at least a portion of the interstices of the cluster of nano carbon crystals is filled with the one or more thermal conductive particles and/or the nanomagnetic material.
The magnetic composite material of claim 1, wherein the nano graphene is a porous graphene ellipsoid, the cluster of carbon nanomaterials is a graphene cluster comprising a plurality of porous graphene ellipsoids arranged in an orderly manner, and the nano metal sulfide is a nano zinc sulfide.
The magnetic composite material of claim 8, wherein the plurality of porous graphene ellipsoids are arranged in a three-dimensional array in the graphene cluster.
The magnetic composite material of claim 8, wherein one of the plurality of porous graphene ellipsoids has an equatorial radius in a range of 100 nm-120 nm and a polar radius in a range of 200 nm-250 nm.
The magnetic composite material of claim 10, wherein one of the plurality of porous graphene ellipsoids has a pore diameter in a range of 14 nm-25 nm.
The magnetic composite material of claim 8, wherein a ratio of a particle size of the nano zinc sulfide to a pore size of one of the plurality of porous graphene ellipsoids is in a range of 1: 8-1: 12.
The magnetic composite material of claim 8, wherein a mass ratio of the nano zinc sulfide to the graphene cluster is in a range of 1: 3-1: 5.
The magnetic composite material of claim 8, wherein the magnetic composite material further comprises a functional nanomaterial, the functional nanomaterial being fused into the graphene cluster, wherein the functional nanomaterial includes a transition metal compound nanomaterial and/or a porous silicon carbide nanomaterial.
The magnetic composite material of claim 14, wherein the transition metal compound nanomaterial includes at least one of a hard magnetic ferrite nanomaterial, a silver nanomaterial, a ferrochromium cobalt alloy nanomaterial, a platinum cobalt alloy nanomaterial, or a ferronickel alloy nanomaterial.
The magnetic composite material of claim 15, wherein the transition metal compound nanomaterial has a particle size in a range of 5 nm-15 nm, and a mass ratio of the transition metal compound nanomaterial to the graphene cluster is in a range of 1: 3-1: 8.
The magnetic composite material of claim 1, wherein the magnetic composite material further comprises an organic insulating material.
A method of preparing a magnetic composite material of any one of claims 1-7 and 17, comprising: preparing a suspension of the nano tungsten disulfide and a suspension of the nano carbon crystal cluster, respectively; heating the suspension of the nano carbon crystal cluster to obtain a precipitate; and mixing the nano tungsten disulfide and the precipitate to obtain the magnetic composite material.
The method of claim 18, wherein the nano tungsten disulfide is prepared according to operations including: reacting tungsten chloride with thioacetamide in a solution to obtain a solid product; wherein a mass percent of the tungsten chloride in the solution is in a range of 0.4%-0.7%, a mass percent of the thioacetamide in the solution is in a range of 0.9%-1.2%, a reaction temperature is in a range of 270℃-290℃, and a reaction time is in a range of 12 h-24 h; and sulfurizing the solid product to obtain the nano tungsten disulfide.
The method of claim 18, wherein the nano carbon crystal cluster is prepared according to operations including: mixing a hydrogen peroxide solution with a dispersion of a first graphene oxide to obtain a solution of a second graphene oxide, wherein an oxidation degree of the second graphene oxide is greater than an oxidation degree of the first graphene oxide; reacting and concentrating the solution of the second graphene oxide and a suspension of porous graphene oxide under a heating condition to obtain a concentrated product; and drying the concentrated product to obtain the nano carbon crystal cluster.
The method of claim 20, wherein a pore diameter of the porous graphene oxide is 1.5-3 times a maximum diameter of the nano tungsten disulfide.
The method of claim 20, wherein a mass ratio of the second graphene oxide to the porous graphene oxide is in a range of 1: 1-1: 3.
The method of claim 20, wherein a ratio of a mass percent of hydrogen peroxide in the hydrogen peroxide solution to a mass percent of the first graphene oxide in the dispersion of the first graphene oxide is in a range of 1: 10-1: 35.
The method of claim 18, wherein the mixing the nano tungsten disulfide and the precipitate to obtain the magnetic composite material comprises: preparing a suspension of the precipitate; mixing the suspension of the precipitate with the nano tungsten disulfide to obtain an initial magnetic composite material; and annealing the initial magnetic composite under a protective gas to obtain the magnetic composite material.
A method of preparing a magnetic composite material of any one of claims 1 and 8-17, comprising: preparing the graphene cluster based on a colloid crystal templating technique using poly (methyl vinyl acid ethyl ester) as a colloid crystal template under a first heating condition, wherein the first heating condition comprises heating for 20 h-28 h at 180℃-220℃; and mixing the graphene cluster with the nano zinc sulfide under a second heating condition to obtain the magnetic composite material.
A wave-absorbing material made based on a magnetic composite material of any one of claims 1-25.
An electronic device including a wave-absorbing material of claim 26.