Mxene-based electromagnetic shielding material anchoring 0 / 2-dimensional magnetic metal and preparation and application thereof

Abstract

The application provides a kind of anchoring 0 / 2 dimensional magnetic metal MXene-based electromagnetic shielding material and its preparation and application, the electromagnetic shielding material includes MXene material, near 0-dimensional magnetic alloy microspheres and 2-dimensional sheet magnetic metal, MXene material has sheet structure, magnetic alloy microspheres and sheet magnetic metal are embedded between the sheet of MXene material, the mass of magnetic alloy microspheres accounts for 8.3%-33.3% of the total mass of electromagnetic shielding material, sheet magnetic metal accounts for 8.3%-33.3% of the total mass of electromagnetic shielding material.The preparation method of the electromagnetic shielding material adopts the direct composite mode of anion surfactant and ultrasonic technology.The preparation method of the application is simple, and the component ratio is easy to control.The electromagnetic shielding material prepared has rich electromagnetic loss mechanism, large effective shielding bandwidth, and significant electromagnetic shielding efficiency, and has wide application prospect in MEMS sensor packaging, automotive electronic products, stealth warplanes, wearable electronic devices and electromagnetic interference prevention.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electromagnetic shielding composite materials, in particular to a MXene-based electromagnetic shielding material anchoring 0 / 2-dimensional magnetic metal and preparation and application thereof. BACKGROUND

[0002] The rapid development of wireless communication technology greatly promotes the popularization of electronic devices in daily life, but also produces a large amount of electromagnetic pollution, which not only affects human health, but also interferes with the normal use of sensors and precision electronic devices, and affects their measurement accuracy. Therefore, the preparation of efficient electromagnetic shielding materials is crucial to improve the electromagnetic environment, ensure the normal operation of electronic devices, and improve the measurement accuracy of precision measurement equipment. At the same time, with the wide application of centimeter and millimeter waves in modern information technology, electromagnetic shielding materials will further develop in the direction of wide frequency. However, traditional electromagnetic shielding materials, such as metals and conductive polymers, are difficult to meet these requirements due to their susceptibility to corrosion, large volume, non-magnetic, single electromagnetic loss mechanism, etc. In recent years, researchers have explored various electromagnetic loss materials, including carbon nanotubes, graphene, silver nanowires, zinc oxide, metal-organic frameworks, silicon carbide, and molybdenum disulfide. However, these materials have a single electromagnetic loss mechanism, and electromagnetic waves are reflected due to impedance mismatch, causing secondary pollution.

[0003] Two-dimensional material MXene with high electrical conductivity has become the most promising electromagnetic shielding material due to its strong electromagnetic wave dissipation capability. MXene is a new type of two-dimensional material composed of transition metal carbide, nitride or carbonitride, with an electrical conductivity of about 2.4×10 5 S / m, much higher than that of graphene. In addition, MXene has a unique layered structure, rich surface groups and high specific surface area, so it shows high electromagnetic shielding performance. However, due to its non-magnetic properties, limited attenuation mechanism and ultra-high electrical conductivity, it leads to unbalanced electromagnetic parameters, making it impossible to achieve good impedance matching, which means that electromagnetic waves cannot be effectively absorbed and dissipated. Therefore, although pure MXene has high potential in the field of electromagnetic shielding, it is not suitable for direct use as an electromagnetic shielding material. Magnetic metal particles such as nickel, cobalt and nickel-cobalt alloy are considered to be powerful candidates for enhancing electromagnetic wave attenuation due to their high Snoek limit, high magnetic permeability and high magnetic saturation induction in the GHz range. Introducing magnetic particles into two-dimensional MXene is an effective way to change its impedance matching characteristics and enrich its electromagnetic loss capability. However, the current process of introducing magnetic particles into MXene is complex, the mass composition of the introduced particles is difficult to control, and most of the particles are in the form of particles, with a single loss mechanism.

[0004] Therefore, it is urgent to explore an electromagnetic shielding composite material with a simple preparation method, easy-to-control magnetic metal particle introduction quality, rich electromagnetic loss mechanism and large shielding bandwidth. SUMMARY

[0005] In view of the defects in the prior art, the purpose of the present application is to provide a MXene-based electromagnetic shielding material anchoring 0 / 2-dimensional magnetic metals and a preparation and application thereof. The electromagnetic shielding material provided by the present application has a rich electromagnetic loss mechanism, a large effective shielding bandwidth, a simple preparation method and an easy-to-control component ratio.

[0006] According to a first aspect of the present application, a MXene-based electromagnetic shielding material anchoring 0 / 2-dimensional magnetic metals is provided, the electromagnetic shielding material comprising a MXene material, near-0-dimensional magnetic alloy microspheres and 2-dimensional flaky magnetic metals, the MXene material having a sheet structure, the magnetic alloy microspheres and the flaky magnetic metals being embedded between the sheets of the MXene material, the mass of the magnetic alloy microspheres accounting for 8.3%-33.3% of the total mass of the electromagnetic shielding material, and the flaky magnetic metals accounting for 8.3%-33.3% of the total mass of the electromagnetic shielding material.

[0007] Optionally, the MXene material is a MAX phase ceramic.

[0008] Optionally, the particle size of the MXene material is 200-400 mesh.

[0009] Optionally, the magnetic alloy microspheres are any one of magnetic FeCo microspheres, magnetic CoNi microspheres and magnetic FeNi microspheres.

[0010] Optionally, the diameter of the magnetic alloy microspheres is 1-10 μm.

[0011] Optionally, the flaky magnetic metals are any one of nanosheet-shaped nickel, nanosheet-shaped iron and nanosheet-shaped ferroferric oxide.

[0012] Optionally, the edge length of the flaky magnetic metals is 1-20 μm.

[0013] According to a second aspect of the present application, a preparation method of a MXene-based electromagnetic shielding material anchoring 0 / 2-dimensional magnetic metals is provided, the preparation method comprising:

[0014] providing a MXene suspension;

[0015] adding magnetic alloy microspheres to deionized water, adding an anionic surfactant, and ultrasonic dispersion to obtain a magnetic alloy microsphere dispersion;

[0016] Add the flaky magnetic metal powder into deionized water, then add an anionic surfactant, and ultrasonically disperse to obtain a flaky magnetic metal dispersion liquid;

[0017] Mix the MXene suspension, the magnetic alloy microsphere dispersion liquid and the flaky magnetic metal dispersion liquid, and ultrasonically disperse uniformly to obtain a composite liquid;

[0018] Rapidly freeze the composite liquid into shape with liquid nitrogen;

[0019] Vacuum dry the frozen mixture to obtain an anchor 0 / 2-dimensional magnetic metal MXene-based electromagnetic shielding material powder.

[0020] Optionally, the MXene suspension is provided by adding a MAX phase ceramic powder into an etching liquid, stirring under water bath conditions, then centrifuging and washing with water, and then ultrasonically dispersing to obtain the MXene suspension.

[0021] Optionally, the etching liquid is an HCl / LiF composite liquid.

[0022] Optionally, the anionic surfactant is any one of sodium dodecyl benzene sulfonate, sodium dodecyl sulfate and sodium diisooctyl sulfosuccinate.

[0023] According to a third aspect of the present application, the MXene-based electromagnetic shielding material of the first aspect or the MXene-based electromagnetic shielding material prepared by the method of the second aspect is applied to any one of MEMS sensor packaging, automotive electronic products, stealth warplanes and wearable electronic devices.

[0024] Compared with the prior art, the present application has at least one of the following beneficial effects:

[0025] 1、The present application forms a MXene-based electromagnetic shielding material by introducing near 0-dimensional magnetic alloy microspheres and 2-dimensional flaky magnetic metals into MXene materials, the MXene materials provide dielectric loss and multiple reflection loss capabilities, the near 0-dimensional magnetic alloy microspheres and 2-dimensional flaky magnetic metals provide magnetic loss and reflection loss, thereby not only making up for the magnetic loss capability of the electromagnetic shielding material, but also the 2-dimensional flaky magnetic metals reflecting electromagnetic waves like MXene nanosheets, increasing the propagation path of electromagnetic waves, thereby further enhancing the electromagnetic wave attenuation capability of the material, the MXene-based electromagnetic shielding material provided by the present application has rich electromagnetic loss mechanisms, has high electromagnetic shielding capability in a wide frequency band range, and has significant electromagnetic shielding efficiency.

[0026] 2、The MXene is mixed with the magnetic alloy microspheres and the sheet-shaped magnetic metal by directly adopting an anionic surfactant and an ultrasonic process, which is different from a chemical composite process, the method can more accurately adjust the proportion of different single materials, the direct composite method is simple in process, and various component proportions are easy to control, so that the electromagnetic shielding material with good shielding efficiency is prepared.

[0027] 3、The electromagnetic shielding material prepared in the application can be used as a coating, a filling material or a composite film, so that it can be applied in multiple scenes, the MXene-based electromagnetic shielding material provided by the application has a wide effective shielding bandwidth and a significant electromagnetic shielding efficiency, and has a wide application prospect in MEMS sensor packaging, automobile electronic products, stealth warplanes and wearable electronic devices. BRIEF DESCRIPTION OF DRAWINGS

[0028] Other characteristics, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments, made with reference to the accompanying drawings:

[0029] Figure 1 A structure schematic diagram of the MXene-based electromagnetic shielding material anchoring 0 / 2-dimensional magnetic metal in the embodiment 1 of the application;

[0030] Figure 2 A scanning electron microscope image of the MXene-based electromagnetic shielding material powder anchoring 0 / 2-dimensional magnetic metal in the embodiment 1 of the application;

[0031] Figure 3 An electromagnetic shielding efficiency diagram of the MXene-based electromagnetic shielding material anchoring 0 / 2-dimensional magnetic metal in the embodiment 1 of the application in the range of 2-18 GHz;

[0032] Figure 4 An electromagnetic shielding efficiency diagram of the MXene-based electromagnetic shielding material anchoring 0 / 2-dimensional magnetic metal in the embodiment 2 of the application in the range of 2-18 GHz;

[0033] Figure 5 An electromagnetic shielding efficiency diagram of the MXene material in the comparative example of the application in the range of 2-18 GHz. DETAILED DESCRIPTION

[0034] The application will be described in detail below with specific embodiments. The following embodiments will help those skilled in the art to further understand the application, but do not limit the application in any form. It should be pointed out that, for those skilled in the art, without departing from the concept of the application, a number of modifications and improvements can be made. These all belong to the protection scope of the application.

[0035] The embodiment of the present application provides a kind of MXene-based electromagnetic shielding material for anchoring 0 / 2-dimensional magnetic metal, specifically, the electromagnetic shielding material includes MXene material, near 0-dimensional (i.e. close to 0-dimensional) magnetic alloy microspheres and 2-dimensional sheet-shaped magnetic metal, MXene material presents large surface area sheet structure, which provides dielectric loss and multiple reflection loss capability, magnetic alloy microspheres and sheet-shaped magnetic metal provide magnetic loss and reflection loss, since MXene material has sheet structure, magnetic alloy microspheres and sheet-shaped magnetic metal are embedded between the sheet layers of MXene material, the mass of magnetic alloy microspheres accounts for 8.3%-33.3% of the total mass of electromagnetic shielding material, and sheet-shaped magnetic metal accounts for 8.3%-33.3% of the total mass of electromagnetic shielding material.

[0036] In some preferred embodiments, in the MXene-based electromagnetic shielding composite material, the addition amount of magnetic alloy microspheres is 16.7%-25%, and the addition amount of sheet-shaped magnetic metal is 16.7%-25%.

[0037] In the embodiment of the present application, the addition amount of magnetic alloy microspheres is set according to its influence on the conductivity of the composite material and the magnetic loss, and a suitable addition ratio can improve the impedance mismatch caused by the ultra-high conductivity of the MXene material itself, thereby enhancing the absorption of electromagnetic waves, and at the same time, due to the magnetism of the magnetic alloy microspheres, the composite material has a certain magnetic loss capability. The addition amount of sheet-shaped magnetic metal is determined according to its influence on the conductivity, magnetic loss and reflection loss of the composite material. In addition to having the same effect as the above-mentioned magnetic alloy microspheres, due to its special sheet structure, sheet-shaped magnetic metal can reflect electromagnetic waves and enhance the shielding performance of the composite material.

[0038] When the percentage of magnetic alloy microspheres and sheet-shaped magnetic metal in the total mass of the composite material is set to 8.3%-33.3%, preferably, 16.7%-25%, it will not have a greater impact on the conductivity of the composite material, and at the same time, it will also achieve better impedance matching characteristics, and the conductivity loss and magnetic loss are best coordinated, with better electromagnetic shielding performance. In contrast, if the addition amount of magnetic particles (magnetic alloy microspheres and sheet-shaped magnetic metal) is too small, it will destroy the high conductivity of the original MXene material, and the magnetic loss capability it provides cannot make up for the loss of shielding performance; while too high magnetic particle doping amount will cause agglomeration, greatly reducing the shielding characteristics of the composite material.

[0039] In some embodiments, the MXene material is a MAX phase ceramic, which can be Ti3AlC2, Nb2AlC, V2AlC, Ti3AlCN, etc. The MAX phase ceramic material is a ternary layered compound, in which: M represents a transition metal, such as titanium, niobium, molybdenum, etc.; A represents a main group element, such as aluminum, silicon, tin, etc.; and X represents carbon or nitrogen. The three elements are arranged in a certain ratio and structure to form a material with a hexagonal layered structure. The MXene material obtained by subsequent etching of the MAX phase ceramic material has the advantages of large surface area, high electrical conductivity, and rich surface functional groups. The high electrical conductivity of MXene greatly reflects electromagnetic waves, and the electromagnetic waves incident on the material surface also undergo conductive loss; its unique sheet structure also reflects electromagnetic waves, causing further dissipation of electromagnetic waves, and its surface groups can act as polarization sites for polarization loss, so MXene is a relatively potential electromagnetic shielding material. The particle size of the MXene material is mainly determined according to the surface area of the sheet-shaped MXene formed after etching. In theory, a larger surface area will provide more attachment sites for magnetic alloy microspheres and sheet-shaped magnetic metals, and it is also easier to form a good conductive path to reflect electromagnetic waves to a greater extent. Preferably, the particle size of the MAX material for preparing MXene is 200-400 mesh.

[0040] Illustratively, the MAX material for preparing MXene is Ti3AlC2 with a particle size of 200 mesh.

[0041] In some embodiments, the magnetic alloy microspheres are any one of magnetic FeCo microspheres, magnetic CoNi microspheres, and magnetic FeNi microspheres, which can reduce the impedance mismatch phenomenon caused by the high electrical conductivity of pure MXene samples, and can also enrich the magnetic loss capability of the composite material. The diameter of the magnetic alloy microspheres mainly considers whether it will damage the electrical conductivity of the original MXene material. If the diameter is too large, it will cause great damage to the sheet-shaped morphology of the MXene material, thereby greatly damaging the conductive path of the composite material and causing a decrease in electromagnetic shielding performance. Preferably, the diameter of the magnetic alloy microspheres is 1-10 μm.

[0042] Illustratively, the magnetic alloy microspheres are FeCo alloy, and the diameter of the FeCo alloy microspheres is 1-2 μm.

[0043] In some embodiments, the sheet-shaped magnetic metal is any one of nanosheet-shaped nickel, nanosheet-shaped iron and nanosheet-shaped ferrite trioxide, all of which have high magnetic permeability, are easy to process in a sheet-shaped structure, can effectively improve the impedance matching characteristics of the composite material, enrich the magnetic loss capacity, and the sheet-shaped structure can further reflect electromagnetic waves. The edge length of the sheet-shaped magnetic metal mainly considers the influence on the conductive path and the influence on the reflection loss of electromagnetic waves. The edge length should not be too small, otherwise it cannot reflect electromagnetic waves, and the edge length should not be too large, so as to avoid mutual stacking with the MXene sheet and damage the conductive path. Preferably, the edge length of the sheet-shaped magnetic metal is 1-20 μm.

[0044] Exemplarily, the sheet-shaped magnetic metal is nanosheet-shaped Ni, and the edge length of the nanosheet-shaped Ni is 1-5 μm.

[0045] The electromagnetic shielding material in the above embodiments of the present application comprises a dielectric loss material MXene, near 0-dimensional magnetic alloy microspheres and near 2-dimensional sheet-shaped magnetic metal. The MXene material can cause Ohmic loss, interfacial polarization loss and multiple reflection loss due to its good electrical conductivity, unique layered structure and surface groups. The zero-dimensional alloy microspheres can reduce the high electrical conductivity caused by MXene in the composite material, improve the impedance matching characteristics, and under the action of alternating electromagnetic waves, can also cause natural resonance and exchange resonance loss of electromagnetic waves with other magnetic alloy microspheres. In addition to providing magnetic loss capacity, the sheet-shaped magnetic metal can also reflect electromagnetic waves like the MXene material, increase the propagation path of electromagnetic waves, and further enhance the electromagnetic wave attenuation capacity of the composite material. The electromagnetic loss mechanism of the composite material provided in the embodiments of the present application is rich, the composite material has high electromagnetic shielding capacity in a wide frequency band range, and the electromagnetic shielding efficiency is significantly improved.

[0046] The present application provides a preparation method of the above-mentioned MXene-based electromagnetic shielding composite material anchoring 0 / 2-dimensional magnetic metal, comprising:

[0047] S1, providing a MXene suspension;

[0048] S2, adding magnetic alloy microspheres into deionized water, then adding an anionic surfactant, exemplarily, the anionic surfactant is sodium dodecyl benzene sulfonate (SDBS), sodium dodecyl sulfate, sodium sulfosuccinic acid diisooctyl ester, etc., and ultrasonic dispersion is performed to obtain a magnetic alloy microsphere dispersion liquid;

[0049] S3, adding sheet-shaped magnetic metal powder into deionized water, then adding an anionic surfactant, exemplarily, the anionic surfactant is sodium dodecyl benzene sulfonate, and ultrasonic dispersion is performed to obtain a sheet-shaped magnetic metal dispersion liquid;

[0050] S4, the MXene suspension, magnetic alloy microsphere dispersion liquid and flaky magnetic metal dispersion liquid are mixed, shaken and uniformly dispersed by ultrasonic, to obtain a composite liquid;

[0051] S5, the composite liquid is rapidly frozen into shape by liquid nitrogen;

[0052] S6, the frozen mixture is placed in a freeze dryer for vacuum drying, to obtain a MXene-based electromagnetic shielding material powder anchored with 0 / 2-dimensional magnetic metal.

[0053] The above embodiment of the application directly uses an anionic surfactant such as sodium dodecyl benzene sulfonate to composite different proportions of magnetic alloy microspheres and flaky magnetic metal on the MXene material. When the anionic surfactant contacts with deionized water in the solution, anions are ionized and tightly adsorbed on the surface of the magnetic particles, which are called surface ions. In the water medium, ions with opposite charges are called counter ions. A part of the counter ions are tightly combined with the magnetic particles and the surface ions by electrostatic adsorption, which are called bound counter ions, and form a tight layer, which becomes a whole in the water medium. Another part of the counter ions forms a diffusion layer by dispersing around. The -OH and -F functional groups introduced in the preparation process of the MXene material make it itself negatively charged, so that it is compounded with the positively charged magnetic particles under the action of electrostatic adsorption. Then the composite liquid is rapidly freeze-dried by liquid nitrogen, and finally the MXene / magnetic alloy microsphere / flaky magnetic metal composite material is prepared by the freeze-drying method. The direct compounding method adopted in the embodiment of the application has a simple preparation process and is easy to control the proportion of various components.

[0054] In some embodiments, the MXene suspension is provided, comprising: adding a MAX phase ceramic powder into an etching liquid, stirring under water bath conditions, then centrifuging and washing with water, and then ultrasonic dispersion, to obtain the MXene suspension.

[0055] In some embodiments, the etching liquid is an HCl / LiF composite liquid.

[0056] In the above embodiment of the application, the ultrasonic power should not be too large, and the time can be appropriately prolonged. For example, in steps S2-S4, the ultrasonic power is 160W, and the ultrasonic time is 15min.

[0057] Ti3C2T x MXene / FeCo / Ni composite material, Ti3C2T x The preparation method of the MXene / FeCo / Ni composite material comprises the following steps:

[0058] S1, Ti3C2T x nanosheets are obtained by configuring an HCl / LiF etching liquid to strip Ti3AlC2, and then Ti3C2Tx MXene nanoplatelet dispersion liquid;

[0059] S2, FeCo alloy particles are added to deionized water, and SDBS is added, ultrasonic dispersion is carried out, and FeCo alloy particle dispersion liquid is obtained;

[0060] S3, Ni sheet powder is added to deionized water, and SDBS is added, ultrasonic dispersion is carried out, and Ni sheet dispersion liquid is obtained;

[0061] S4, the Ti3C2T x MXene suspension is mixed with the FeCo alloy dispersion liquid and the Ni sheet dispersion liquid obtained in steps S2 and S3, and ultrasonic dispersion is carried out, and Ti3C2T x MXene / FeCo / Ni mixed dispersion liquid;

[0062] S5, the uniformly dispersed liquid obtained in step S4 is rapidly frozen with liquid nitrogen;

[0063] S6, the frozen and formed mixture obtained in step S5 is placed in a freeze dryer, vacuum drying is carried out for 36h, and Ti3C2T x MXene / FeCo / Ni composite material powder.

[0064] Unlike the chemical compounding process, the above-mentioned embodiments of the present application directly use anionic surfactants and subsequent ultrasonic processes to mix MXene and magnetic metals, the process is simple, and the proportion of different elemental materials can be more accurately adjusted, thereby solving the problems of complicated preparation process of embedding magnetic particles into the interlayer of MXene and difficulty in controlling the sample content.

[0065] The application of the MXene-based electromagnetic shielding material provided by the embodiments of the present application is introduced into the composite material by introducing magnetic alloy microspheres with low coercivity and high saturation magnetization and sheet-shaped magnetic metals, which not only makes up for the magnetic loss ability of the composite material, but also reflects electromagnetic waves like MXene nanosheets, increases the propagation path of electromagnetic waves, and further enhances the electromagnetic wave attenuation ability of the composite material, so that the electromagnetic loss mechanism is rich, has the characteristics of large effective shielding bandwidth and significant electromagnetic shielding efficiency, and becomes a promising candidate material in electromagnetic shielding applications. The composite material in the above-mentioned embodiments of the present application can be used as a coating for coating, or as a filling material or prepared into a composite film, so as to be applied in multiple scenes. The above-mentioned composite material can be applied to any one of high-precision MEMS sensor packaging, automotive electronic products (automotive chips), stealth warplanes and wearable electronic devices, and realizes good electromagnetic shielding packaging effect.

[0066] The scheme of the present application will be explained below in connection with specific examples and comparative examples. Those skilled in the art can understand that the examples below are only for illustration of the present application and should not be regarded as limiting the scope of the present application. If no specific technology or condition is specified in the examples, the technology or condition described in the literature in the art or according to the product manual is used. If no manufacturer of the reagent or instrument is specified, it is a conventional product that can be obtained by marketable means.

[0067] Example 1

[0068] The MXene-based electromagnetic shielding material provided in this example anchors 0 / 2-dimensional magnetic metal, the percentage of FeCo alloy particles in the total mass of the electromagnetic shielding material is 25%, and the percentage of Ni sheet in the total mass of the electromagnetic shielding material is 25%, and the preparation method comprises the following steps:

[0069] 1. Ti3C2T x Preparation of nanosheets: First, 40 ml of 9 mol / L HCl solution was prepared and added to a Teflon beaker for standby, then 2 g of LiF powder was added to a Teflon beaker, and magnetic stirring was carried out under a 38℃ water bath environment for 20 minutes. Then 2 g of Ti3AlC2 was slowly added to the container in small amounts for etching reaction. After 48 hours of reaction, centrifugation was carried out at 4750 rpm, and the precipitate was washed several times with deionized water until the pH was 6. Then a high-power ultrasonic machine was used for treatment (180W, 40min), followed by centrifugation (4750rpm, 10min), and finally the black upper suspension in the centrifuge tube was collected.

[0070] 2. The 5ml MXene suspension was filtered into a film using a vacuum filtration device (device caliber 55mm, pressure 5000Pa, membrane material cellulose, pore size 0.22um), and after drying and removing the film, the mass was measured to obtain a concentration of 7mg / ml.

[0071] 3. FeCo alloy particles with a diameter of 1-2μm and a mass of 75mg were added to 20ml deionized water, and 20mg SDBS was added, ultrasonic dispersion was carried out, the ultrasonic power was 160W, and the ultrasonic time was 15min, to obtain a FeCo alloy particle dispersion of 3.75mg / ml.

[0072] 4. Ni sheet powder with a diameter of 1-5μm and a mass of 75mg was added to deionized water, and 20mg SDBS was added, ultrasonic dispersion was carried out, the ultrasonic power was 160W, and the ultrasonic time was 15min, to obtain a Ni sheet dispersion of 3.75mg / ml.

[0073] 5. Take 21.5 ml of the MXene suspension obtained in step 1, 20 ml of the FeCo alloy dispersion with a concentration of 3.75 mg / ml obtained in step 3, and 20 ml of the Ni sheet dispersion with a concentration of 3.75 mg / ml obtained in step 4, mix and shake well, and then ultrasonically disperse using a power of 160 W for 15 min to obtain Ti3C2T. x MXene / FeCo / Ni mixed dispersion.

[0074] 6. Quickly freeze the uniform dispersion obtained in step 5 with liquid nitrogen.

[0075] 7. Place the freeze-formed mixture obtained in step 6 into a freeze dryer and dry it under vacuum for 36 hours to obtain Ti3C2T. x MXene / FeCo / Ni composite powder.

[0076] A schematic diagram of the composite material structure is shown below. Figure 1 As shown, the large sheet-like structures are MXene obtained through etching, the embedded spherical structures are FeCo alloy microspheres, and the small sheet-like structures are Ni sheets. Scanning electron microscopy (SEM) results are shown below. Figure 2 As shown, the three materials, sheet-like MXene, FeCo alloy magnetic microspheres, and sheet-like Ni, are well mixed, and the magnetic alloy microspheres and Ni sheets are relatively uniformly embedded in the MXene layers.

[0077] The composite material prepared in Example 1 was doped with 30 mg of paraffin and pressed into a coaxial ring with an outer diameter of 7 mm and an inner diameter of 3 mm. Its S-parameters in the coaxial air line at 2-18 GHz were measured using a vector network analyzer. The results are as follows: Figure 3 As shown. According to Figure 3 In Example 1, the average electromagnetic shielding effectiveness of the composite material was 46.2 dB. The average electromagnetic shielding effectiveness was 37.3 dB in the S-band, 40.9 dB in the C-band, 46.2 dB in the X-band, and 52.6 dB in the Ku-band, with a maximum electromagnetic shielding effectiveness of 57.2 dB.

[0078] Example 2

[0079] The MXene-based electromagnetic shielding material anchored to 0 / 2D magnetic metals provided in this embodiment has FeCo alloy particles accounting for 16.7% of the total mass of the electromagnetic shielding material, and Ni sheets accounting for 16.7% of the total mass of the electromagnetic shielding material. Its preparation method includes the following steps:

[0080] According to Example 1, the experimental conditions for steps 1 to 2 are completely identical.

[0081] 3. Add 50 mg FeCo alloy particles with a diameter of 1-2 μm to 20 ml of deionized water and add 20 mg SDBS. Disperse the particles by ultrasonication at a power of 160 W for 15 min to obtain a 2.5 mg / ml FeCo alloy particle dispersion.

[0082] 4. Add 50 mg of Ni sheet powder with a diameter of 1-5 μm to deionized water and add 20 mg of SDBS. Disperse the powder by ultrasonication at a power of 160 W for 15 min to obtain a Ni sheet dispersion of 2.5 mg / ml.

[0083] 5. Take 28.5 ml of the MXene suspension obtained in step 1, 20 ml of the FeCo alloy dispersion with a concentration of 2.5 mg / ml obtained in step 3, and 20 ml of the Ni sheet dispersion with a concentration of 2.5 mg / ml obtained in step 4, mix and shake well, and then ultrasonically disperse using a power of 160 W for 15 min to obtain Ti3C2T. x MXene / FeCo / Ni mixed dispersion.

[0084] According to Example 1, the experimental conditions for steps 6 to 7 are completely identical.

[0085] The composite material prepared in Example 2 was doped with 30 mg of paraffin and pressed into a coaxial ring with an outer diameter of 7 mm and an inner diameter of 3 mm. Its S-parameters in the coaxial air line were measured using a vector network analyzer from 2 to 18 GHz. The results are as follows: Figure 4 As shown. According to Figure 4 In Example 2, the average electromagnetic shielding effectiveness of the composite material was 51.2 dB. The average electromagnetic shielding effectiveness was 39.4 dB in the S-band, 43.1 dB in the C-band, 50.0 dB in the X-band, and 61.2 dB in the Ku-band, with a maximum electromagnetic shielding effectiveness of 69.8 dB.

[0086] Comparative Example

[0087] A comparative example provides a pure MXene electromagnetic shielding material, the preparation method of which includes the following steps:

[0088] According to Example 1, the experimental conditions for steps 1 and 2 are completely identical.

[0089] 3. Take 42.8 ml of the MXene suspension obtained in step 1 and freeze the suspension rapidly with liquid nitrogen.

[0090] 4. The freeze-formed mixture was placed in a freeze dryer and dried under vacuum for 36 hours to obtain Ti3C2T. xMXene powder.

[0091] The composite material prepared in the comparative example was doped with 30 mg of paraffin, pressed into a coaxial ring with an outer diameter of 7 mm and an inner diameter of 3 mm, and the S parameters thereof in the frequency range of 2-18 GHz were measured in a coaxial air line using a vector network analyzer, and the results are shown in Figure 5 According to Figure 5 , the average electromagnetic shielding effectiveness of the composite material in the comparative example was 40.2 dB. The average electromagnetic shielding effectiveness in the S band was 38.5 dB, the average electromagnetic shielding effectiveness in the C band was 38.4 dB, the average electromagnetic shielding effectiveness in the X band was 40.0 dB, the average electromagnetic shielding effectiveness in the Ku band was 45.1 dB, and the highest electromagnetic shielding effectiveness could reach 42.0 dB. Compared with the pure MXene electromagnetic shielding material in the comparative example, the material in the above embodiments of the present application has higher electromagnetic shielding capability in a wider frequency band range, which shows that by introducing magnetic alloy microspheres and sheet-shaped magnetic metals into the MXene material to form a composite material, the electromagnetic shielding effectiveness of the composite material can be significantly improved.

[0092] The specific embodiments of the present application are described above. It should be understood that the present application is not limited to the specific embodiments described above, and various modifications or changes can be made by those skilled in the art within the scope of the claims, which does not affect the essential content of the present application. The above preferred features can be used in combination as long as they do not conflict with each other.

Claims

1. An MXene-based electromagnetic shielding material anchoring 0 / 2-dimensional magnetic metal, characterized in that, The electromagnetic shielding material comprises a MXene material, near 0-dimensional magnetic alloy microspheres and 2-dimensional flaky magnetic metal, the MXene material has a sheet structure, the magnetic alloy microspheres and the flaky magnetic metal are embedded between the sheets of the MXene material, the mass of the magnetic alloy microspheres accounts for 8.3%-33.3% of the total mass of the electromagnetic shielding material, and the flaky magnetic metal accounts for 8.3%-33.3% of the total mass of the electromagnetic shielding material. 2.The MXene-based electromagnetic shielding material anchoring 0 / 2-dimensional magnetic metal of claim 1, wherein, The MXene material is a MAX phase ceramic. 3.The MXene-based electromagnetic shielding material anchoring 0 / 2-dimensional magnetic metal of claim 1, wherein, The particle size of the MXene material is 200-400 mesh. 4.The MXene-based electromagnetic shielding material anchoring 0 / 2-dimensional magnetic metal of claim 1, wherein, The magnetic alloy microspheres are any one of magnetic FeCo microspheres, magnetic CoNi microspheres and magnetic FeNi microspheres; the diameter of the magnetic alloy microspheres is 1-10 μm.

5. The MXene-based electromagnetic shielding material anchoring 0 / 2-dimensional magnetic metal of claim 1, wherein, The flaky magnetic metal is any one of nanoscale flaky nickel, nanoscale flaky iron and nanoscale flaky ferroferric oxide; the edge length of the flaky magnetic metal is 1-20 μm.

6. A method of preparing the MXene-based electromagnetic shielding material anchoring 0 / 2-dimensional magnetic metal according to any one of claims 1-5, characterized in that, Comprising: providing a MXene suspension; adding magnetic alloy microspheres to deionized water, then adding an anionic surfactant, ultrasonic dispersion to obtain a magnetic alloy microsphere dispersion; adding flaky magnetic metal powder to deionized water, then adding an anionic surfactant, ultrasonic dispersion to obtain a flaky magnetic metal dispersion; mixing the MXene suspension, the magnetic alloy microsphere dispersion and the flaky magnetic metal dispersion, and ultrasonic dispersion to obtain a composite liquid; rapidly freezing the composite liquid into shape with liquid nitrogen; vacuum drying the frozen mixture to obtain an anchored 0 / 2-dimensional magnetic metal MXene-based electromagnetic shielding material powder.

7. The method of claim 6, wherein the MXene-based electromagnetic shielding material anchoring 0 / 2-dimensional magnetic metal is prepared by, The method for providing a MXene suspension comprises adding a MAX phase ceramic powder to an etching solution, stirring under water bath conditions, then centrifugal washing, ultrasonic dispersion to obtain a MXene suspension.

8. The method of claim 7, wherein the MXene-based electromagnetic shielding material anchoring 0 / 2-dimensional magnetic metal is prepared by, The etching solution is an HCl / LiF composite solution.

9. The method of claim 6, wherein the MXene-based electromagnetic shielding material anchoring 0 / 2-dimensional magnetic metal is prepared by, The anionic surfactant is any one of sodium dodecylbenzenesulfonate, sodium dodecyl sulfate and sodium dioctyl sulfosuccinate.

10. Use of the electromagnetic shielding material according to any one of claims 1 to 5 or of the electromagnetic shielding material prepared by the method according to any one of claims 6 to 9, characterized in that, The MXene-based electromagnetic shielding material is applied to any one of MEMS sensor packaging, automotive electronic products, stealth warplanes and wearable electronic devices.

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