Wave-absorbing material, preparation method and application thereof

Abstract

The application discloses a wave-absorbing material and a preparation method and application thereof. The wave-absorbing material comprises a wave-absorbing layer and a reflecting layer. The wave-absorbing layer is prepared from a sponge matrix, MXene material and natural rubber. The reflecting layer is prepared from MXene material and natural rubber. The wave-absorbing layer and the reflecting layer are connected through the MXene material. The high conductivity and high electromagnetic shielding performance of the MXene material are combined with the porous structure of the sponge matrix, so that the provided wave-absorbing material has high electromagnetic shielding performance and good mechanical performance. Moreover, the wave-absorbing layer and the reflecting layer of the wave-absorbing material are connected through the MXene material. The continuous structure ensures high absorption rate of electromagnetic waves on one hand, and adjusts the impedance matching characteristics at the interface on the other hand, further improving the absorption rate of electromagnetic waves.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wave-absorbing materials, in particular to a wave-absorbing material and a preparation method and application thereof. BACKGROUND

[0002] With the rapid development of communication technology, especially in the upcoming 6G era, the electromagnetic environment has become increasingly complex. 6G technology not only pursues higher data transmission rates and lower delays, but also strives to achieve more extensive spectrum coverage, including the application of high-frequency bands such as terahertz bands. However, the wavelength of high-frequency electromagnetic waves is extremely short, easily blocked by obstacles, and easily affected by environmental reflection and interference during propagation, which poses a serious challenge to the stability and efficiency of communication systems. Therefore, it is particularly important to develop materials that can effectively absorb and reduce electromagnetic wave reflection.

[0003] In the field of electromagnetic wave absorption, wave-absorbing sponges, as a special type of electromagnetic wave absorbing material, have been widely used in electromagnetic compatibility testing, electromagnetic field protection, antenna design, noise control, and other fields. Although traditional wave-absorbing sponges have good wave-absorbing effects in certain frequency bands, their wave-absorbing frequency bands are often narrow, making it difficult to meet the demand for wide-band wave-absorbing materials in the 6G era. In addition, with the increasing density of base stations and the continuous rise of electromagnetic energy, long-term exposure to high-energy density microwave environments may have adverse effects on human health, further emphasizing the importance of developing efficient wide-band wave-absorbing materials.

[0004] Specifically, most of the wave-absorbing sponges on the market are made of organic polymer materials such as silicone, neoprene, and polyurethane, and are added with wave-absorbing agents such as ferrite, carbon black, and iron oxide to improve wave-absorbing performance. These materials exhibit good wave-absorbing effects in specific frequency bands, but have obvious shortcomings in wide-band frequency ranges. For example, flat plate-type wave-absorbing materials have simple structures but narrow wave-absorbing frequency bands; corner pyramid-type wave-absorbing materials can achieve wide-band absorption, but their structures are complex and prone to wear and deformation, which is not conducive to practical application. In addition, research in the field of wave-absorbing materials has made some progress in recent years. For example, some studies have used quantum materials and semiconductor materials in combination to enhance the quantum effect of materials by reducing their dimensions, thereby improving wave-absorbing performance. However, these new materials have potential, but their preparation process is complex, the cost is high, and their stability and reliability in practical applications still need to be further verified.

[0005] Therefore, the prior art still needs to be improved and developed. SUMMARY

[0006] In view of the deficiencies of the prior art described above, the purpose of the present application is to provide a wave-absorbing material and a preparation method and application thereof, aiming to solve the problem of insufficient wave-absorbing materials in wide-band wave-absorbing.

[0007] The technical solutions of the present application are as follows:

[0008] In a first aspect of the present application, a wave-absorbing material is provided, comprising a wave-absorbing layer and a reflective layer, wherein the wave-absorbing layer is prepared from a mixture comprising a sponge matrix, MXene material and natural rubber, and the reflective layer is prepared from a mixture comprising MXene material and natural rubber.

[0009] Preferably, the wave-absorbing layer is prepared from a mixture comprising 90-95% by mass of the sponge matrix, 7.5-10% by mass of the MXene material and 0-2.5% by mass of the natural rubber.

[0010] Preferably, the reflective layer is prepared from a mixture comprising 75% by mass of the MXene material and 25% by mass of the natural rubber.

[0011] Preferably, the wave-absorbing layer has a thickness of 1-20 mm, and the reflective layer has a thickness of 5-500 microns.

[0012] Preferably, the wave-absorbing layer has a thickness of 1-20 mm, and the reflective layer has a thickness of 5-500 microns.

[0013] In a second aspect of the present application, a method for preparing a wave-absorbing material is provided, comprising the following steps:

[0014] Mixing a solution containing MXene material with a natural rubber solution to obtain a first mixed solution, then immersing a sponge matrix in the first mixed solution to obtain a moist sponge matrix containing MXene material and natural rubber, denoted as a wave-absorbing layer;

[0015] Mixing a solution containing MXene material with a natural rubber solution to obtain a second mixed solution, then performing suction filtration on the second mixed solution, stopping the suction filtration when the second mixed solution disappears to obtain a moist film, denoted as a reflective layer;

[0016] Placing the wave-absorbing layer on the surface of the reflective layer to obtain a wave-absorbing material precursor, then sequentially performing pressing and drying treatments on the wave-absorbing material precursor to obtain the wave-absorbing material.

[0017] Preferably, in the first mixed solution, the mass ratio of MXene material to natural rubber is 3:1.

[0018] Preferably, the time for immersing the sponge matrix in the first mixed solution is 10 minutes.

[0019] Preferably, in the second mixed solution, the mass ratio of MXene material to natural rubber is 3:1.

[0020] Preferably, the temperature of the drying treatment is 60℃, and the time of the drying treatment is 1-12h.

[0021] In a third aspect, the application provides the use of the wave-absorbing material or the wave-absorbing material prepared by the preparation method in the field of electromagnetic wave absorption.

[0022] Beneficial effects: The application provides a wave-absorbing material, a preparation method and an application thereof. The application combines the high conductivity and high electromagnetic shielding performance of MXene material with the porous structure of a sponge matrix, so that the provided wave-absorbing material has high electromagnetic shielding performance and good mechanical performance. In addition, the wave-absorbing layer and the reflective layer of the wave-absorbing material provided by the application are connected by MXene material. The continuous structure ensures high absorption of electromagnetic waves and adjusts the impedance matching characteristics at the interface, further improving the absorption of electromagnetic waves. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a flowchart of the wave-absorbing material prepared by the preferred embodiment of the application.

[0024] Figure 2 is a flexibility display of the wave-absorbing material prepared by example 1 of the application.

[0025] Figure 3 is a scanning electron microscope image of the wave-absorbing material prepared by example 1 of the application.

[0026] Figure 4 is an electromagnetic shielding test diagram of the wave-absorbing material prepared by examples 1-4 and comparative example 1 of the application.

[0027] Figure 5 is an electromagnetic shielding comparison test diagram of the wave-absorbing material prepared by examples 1-4 and comparative example 1 of the application. DETAILED DESCRIPTION

[0028] The application provides a wave-absorbing material, a preparation method and an application thereof. To make the purpose, technical scheme and effects of the application more clear and explicit, the application is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the application and do not limit the application.

[0029] The embodiment of the application provides a wave-absorbing material, which comprises a wave-absorbing layer and a reflective layer. The wave-absorbing layer is prepared from a sponge matrix, MXene material and natural rubber, and the reflective layer is prepared from MXene material and natural rubber.

[0030] The wave-absorbing layer and the reflective layer are connected by MXene material.

[0031] The high conductivity and high electromagnetic shielding performance of the MXene material are combined with the porous structure of the sponge matrix, so that the provided wave-absorbing material has high electromagnetic shielding performance and good mechanical performance. Moreover, the wave-absorbing layer and the reflecting layer of the wave-absorbing material provided by the application are connected by the MXene material, and the continuous structure ensures high absorption of electromagnetic waves and adjusts the impedance matching characteristics at the interface, further improving the absorption of electromagnetic waves.

[0032] Moreover, the wave-absorbing layer and the reflecting layer provided by the application are both prepared from the MXene material and the natural rubber, and new chemical bonds are formed after the combination of the natural rubber and the MXene material. The combination of the two components enhances the bonding force of each component in the wave-absorbing material, thereby enhancing the mechanical strength of the wave-absorbing material, and improves the stability of the wave-absorbing material in special environments, such as water.

[0033] In some embodiments, the wave-absorbing layer is prepared from the sponge matrix with a mass fraction of 90% to 95%, the MXene material with a mass fraction of 7.5% to 10%, and the natural rubber with a mass fraction of 0% to 2.5%.

[0034] In some preferred embodiments, the wave-absorbing layer is prepared from the sponge matrix with a mass fraction of 92%, the MXene material with a mass fraction of 6%, and the natural rubber with a mass fraction of 2%.

[0035] In some preferred embodiments, the wave-absorbing layer is prepared from the sponge matrix with a mass fraction of 90%, the MXene material with a mass fraction of 7.5%, and the natural rubber with a mass fraction of 2.5%.

[0036] In some embodiments, the reflecting layer is prepared from the MXene material with a mass fraction of 75% and the natural rubber with a mass fraction of 25%.

[0037] In some embodiments, the thickness of the wave-absorbing layer is 1mm to 20mm, and the thickness of the reflecting layer is 5μm to 500μm.

[0038] In some preferred embodiments, the thickness of the wave-absorbing layer is 5mm, and the thickness of the reflecting layer is 5μm.

[0039] In some preferred embodiments, the thickness of the wave-absorbing layer is 10mm, and the thickness of the reflecting layer is 10μm.

[0040] With the above mass ratio and thickness, a lighter shielding wave-absorbing material and better flexibility can be obtained, which can be suitable for more application scenarios.

[0041] The preparation method of the wave-absorbing material is provided, which comprises the following steps:

[0042] mixing the solution containing MXene material with the solution of natural rubber to obtain a first mixed solution, then immersing a sponge matrix in the first mixed solution to obtain a wet sponge matrix containing MXene material and natural rubber, denoted as a wave-absorbing layer;

[0043] mixing the solution containing MXene material with the solution of natural rubber to obtain a second mixed solution, then performing suction filtration treatment on the second mixed solution, stopping the suction filtration treatment when the second mixed solution just disappears to obtain a wet film, denoted as a reflecting layer;

[0044] placing the wave-absorbing layer on the surface of the reflecting layer to obtain a wave-absorbing material precursor, and sequentially performing pressing treatment and drying treatment on the wave-absorbing material precursor to obtain the wave-absorbing material.

[0045] In some embodiments, the mass ratio of MXene material to natural rubber in the first mixed solution is 3:1.

[0046] In some embodiments, the time for immersing the sponge matrix in the first mixed solution is 10 min.

[0047] In some embodiments, the mass ratio of MXene material to natural rubber in the second mixed solution is 3:1.

[0048] In some preferred embodiments, the temperature of the drying treatment is 60℃, and the time of the drying treatment is 1-12 h.

[0049] In some embodiments, the temperature of the drying treatment is 60℃, and the time of the drying treatment is 2 h.

[0050] The application also provides the use of the wave-absorbing material in the field of electromagnetic wave absorption.

[0051] The technical solutions in the embodiments of the application will be described clearly and completely below. Obviously, the described embodiments are only some of the embodiments of the application, but not all the embodiments of the application, which are only used to illustrate the application and by no means limit the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the application.

[0052] Preparation Example 1

[0053] Preparation of MXene nanosheets, including the following steps:

[0054] MXene nanosheets were prepared using a chemical etching and intercalation exfoliation method. The procedure was as follows: 12 mL of deionized water was pipetted into a plastic bottle and magnetically stirred at 35°C. 24 mL of 9 M HCl and 5 mL of HF were then added to the stirred bottle to form a mixture. 2 g of Ti3AlC2 powder was then slowly added to the mixture in small increments. Etching was performed at 35°C with stirring for 24 hours. After etching, the mixture was poured into a centrifuge tube and centrifuged at 5000 rpm for two minutes. The supernatant was discarded, and the precipitate was retained. Deionized water was added and centrifuged again. This process was repeated until the pH value was neutral using pH paper. The supernatant was discarded, and the precipitate was retained. 2 g of LiCl was then weighed into a new plastic bottle and heated and stirred at 35°C. The washed neutral precipitate was then rinsed with 120 mL of deionized water into the plastic bottle containing LiCl. The intercalation reaction was continued at 35°C with stirring for 4 hours. The intercalated suspension was transferred to a 50 mL centrifuge tube and centrifuged at 5000 rpm for 2 min. The supernatant was discarded and the precipitate was retained. Deionized water was added and manually shaken to continue washing and centrifugation. The operation was repeated twice. The shaken mixture was then centrifuged at 8000 rpm for 3 min. Deionized water was added and shaken to continue centrifugation at 3500 rpm for 2 min. The upper suspension was placed in a new centrifuge tube to obtain MXene nanosheets.

[0055] Example 1

[0056] Preparation of absorbing materials, such as Figure 1 As shown, the following steps are included:

[0057] Preparation of the absorbing layer: Cut a polyurethane sponge into pieces of 3cm*3cm*2mm in size, repeatedly wash in anhydrous ethanol and deionized water, and dry. Next, use the MXene nanosheets prepared in Example 1 to prepare a 0.5mg / mL MXene solution. Take 20mL of this solution into a small beaker and stir it magnetically. Then, take 1mL of natural rubber (NR) (30mg / mL) and mix it with the MXene solution in a beaker and stir for 10 minutes to obtain a first mixed solution. Then, place the polyurethane sponge into the beaker containing the first mixed solution and vacuum-immerse it in a vacuum drying oven for 10 minutes to obtain a moist polyurethane sponge matrix containing MXene material and natural rubber, thus forming the absorbing layer.

[0058] Preparation of the reflective layer: 2.57 mL of MXene solution (10 mg / mL) prepared by using MXene nanosheets prepared in Example 1 was taken in a small beaker of 50 mL and subjected to magnetic stirring, then a NR solution of 200 mL was prepared with a solid content of 61 wt% and a concentration of 30 mg / mL, and 2 mL of the NR solution of 30 mg / mL was taken in the small beaker containing the MXene solution and stirring was continued for 15 min. After completion of stirring, a film was formed using a vacuum filtration device, and the filtration process was stopped when the second mixed solution just disappeared, obtaining a wet film with a MXene content of 30 wt%, and a reflective layer was obtained.

[0059] Preparation of the wave-absorbing material: The wave-absorbing layer was placed on the reflective layer and pressed uniformly, and then placed in an oven for drying at 60°C for 2 h, obtaining a wave-absorbing material. According to the concentration of the impregnated MXene and the amount of 30 wt% MXene in the composite film, the wave-absorbing material is recorded as MR3P0.5.

[0060] Example 2

[0061] Preparation of the wave-absorbing material, the method of this embodiment is basically the same as that of Example 1, the difference is only that in the preparation of the wave-absorbing layer, the concentration of the MXene solution is 1 mg / mL, and the wave-absorbing material prepared thereby is recorded as MR3P1.

[0062] Example 3

[0063] Preparation of the wave-absorbing material, the method of this embodiment is basically the same as that of Example 1, the difference is only that in the preparation of the wave-absorbing layer, the concentration of the MXene solution is 5 mg / mL, and the wave-absorbing material prepared thereby is recorded as MR3P5.

[0064] Example 4

[0065] Preparation of the wave-absorbing material, the method of this embodiment is basically the same as that of Example 1, the difference is only that in the preparation of the wave-absorbing layer, the concentration of the MXene solution is 10 mg / mL, and the wave-absorbing material prepared thereby is recorded as MR3P10.

[0066] Comparative Example 1

[0067] A preparation method of a wave-absorbing material is as follows: 2.57 mL of MXene solution (10 mg / mL) prepared from MXene nanosheets prepared in Example 1 is taken in a 50 mL small beaker and subjected to magnetic stirring, then a natural rubber solution with a solid content of 61 wt% NR is prepared into 200 mL of a natural rubber solution with a concentration of 30 mg / mL, and 2 mL of the 30 mg / mL natural rubber solution is taken into the above small beaker containing the MXene solution, and stirring is continued for 15 min. After stirring is completed, a film is formed by using a vacuum filtration device, and a thin film with a MXene content of 30 wt% is obtained, which is recorded as MR3.

[0068] Performance detection experiment

[0069] The wave-absorbing material prepared in Example 1 is subjected to flexibility demonstration, as shown in Figure 2 .

[0070] The wave-absorbing material prepared in Example 1 is subjected to electron microscope scanning, as shown in Figure 3 .

[0071] The wave-absorbing materials prepared in Examples 1-4 and Comparative Example 1 are subjected to electromagnetic shielding test, as shown in Figure 4 , in which the black, blue and red rectangular columns in the figure respectively represent the reflection, absorption and transmission attenuation contribution of the materials to electromagnetic waves.

[0072] The wave-absorbing materials prepared in Examples 1-4 and Comparative Example 1 are subjected to electromagnetic shielding comparison test, as shown in Figure 5 .

[0073] It should be understood that the application of the present application is not limited to the above examples, and those of ordinary skill in the art can make improvements or changes according to the above description, and all these improvements and changes shall belong to the protection scope of the appended claims of the present application.

Claims

1. A method for preparing a wave absorbing material, characterized in that: The following steps are involved: A solution containing MXene material and a natural rubber solution are mixed to obtain a first mixed solution, and then a sponge substrate is immersed in the first mixed solution to obtain a wet sponge substrate containing MXene material and natural rubber, which is recorded as an absorbing layer; The solution containing the MXene material is mixed with the natural rubber solution to obtain a second mixed solution, and then the second mixed solution is filtered. The filtration is stopped when the second mixed solution disappears, thereby obtaining a wet film, which is recorded as a reflective layer. The absorbing layer is placed on the surface of the reflecting layer to obtain a absorbing material precursor, and the absorbing material precursor is subjected to a pressing process and a drying process in sequence to obtain the absorbing material.

2. The method for preparing the absorbing material according to claim 1, wherein: In the first mixed solution, the mass ratio of MXene material to natural rubber is 3:

1.

3. The method for preparing the absorbing material according to claim 1, wherein: The sponge matrix was immersed in the first mixed solution for 10 minutes.

4. The method for preparing the absorbing material according to claim 1, wherein: In the second mixed solution, the mass ratio of MXene material to natural rubber is 3:

1.

5. The method for preparing the absorbing material according to claim 1, wherein: The temperature of the drying process is 60° C., and the time of the drying process is 1 to 12 hours.

6. Use of the absorbing material prepared by the preparation method according to any one of claims 1 to 5 in the field of electromagnetic wave absorption.

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