Textile-based absorbing material with both electromagnetic wave absorption properties and flexibility, preparation method and application thereof

Abstract

The present invention relates to the technical field of absorbing materials, and in particular to a textile-based absorbing material having both electromagnetic wave absorption properties and flexibility, as well as a preparation method and application thereof. The invention relates to a ZIF-67-modified absorbing fabric obtained by impregnating a plasma-treated aramid fabric in a ZIF-67 solution, ultrasonically impregnating the fabric, and drying the resulting material. The ZIF-67 / MXene composite-modified absorbing fabric is prepared by an impregnation process, which is then impregnated in a MXene solution, treated in an ultrasonic cleaner, and then dried. Furthermore, a flexible textile aramid fabric is used as a substrate to effectively composite ZIF-67 and MXene. The composite material is flexible, foldable, and lightweight, and the absorbing performance of the composite material is improved by optimizing the impedance matching of the fabric.

Description

Technical Field

[0001] The present invention relates to the technical field of absorbing materials, in particular to a textile-based absorbing material having both electromagnetic wave absorption properties and flexibility, and a preparation method and application thereof. Background Art

[0002] Electromagnetic wave pollution has become another major source of pollution in the 21st century, following air pollution, water pollution, and light pollution. It not only affects the operation of precision instruments but also threatens human health. Furthermore, with the in-depth development of precision-guided weapons, wearable stealth materials have become a key research project in the military equipment of various countries. Therefore, the development of textile composite absorbing materials has important significance and application value for improving the performance of electromagnetic protection materials and national defense security.

[0003] The core of radar stealth technology lies in electromagnetic wave absorbing materials, which effectively attenuate electromagnetic radiation. Existing electromagnetic wave absorbing materials may suffer from poor impedance matching, narrow effective absorption bandwidth, and thick absorbing materials, resulting in poor absorption performance. Electromagnetic wave materials must first possess excellent absorption properties, effectively absorbing incident electromagnetic waves. This reduces or eliminates issues such as transmission, penetration, and leakage. Secondly, electromagnetic wave materials must have a wide effective absorption bandwidth, exhibiting stable absorption performance across different frequency bands and capable of handling a variety of electromagnetic wave signals. Absorbent materials must also be stable and durable, maintaining their absorption performance under varying environmental conditions, such as temperature, humidity, and corrosion. They must also maintain their absorption performance over long periods of use, avoiding issues such as aging, breakage, and cracks.

[0004] CN 102821589B discloses an absorbing material comprising at least one material layer, each of which comprises three substrates, namely, a first substrate, a second substrate, and a third substrate from top to bottom. Each substrate layer comprises at least one substrate unit, and each substrate unit has a metal microstructure attached to its upper surface. The metal microstructures attached to the upper surface of the substrate unit of the first substrate are multiple hollow annular structures of varying sizes, wherein the hollow annular structures of the same size are arranged in a circular array. The metal microstructures attached to the upper surface of the substrate unit of the second substrate are open annular structures, with the two ends of the open annular structure respectively spiraling inward to form two non-intersecting spiral structures. The metal microstructures attached to the upper surface of the substrate unit of the third substrate are complementary to the metal microstructures attached to the substrate unit of the second substrate. The absorbing material having the above structure has good absorbing performance in the low-frequency band.

[0005] In the modern military, stealth fighters, capable of evading radar detection, offer a preemptive and deterrent capability. This also serves as a reminder for all nations to prioritize the development of electromagnetic absorbers and the production of superior materials. The aforementioned patent utilizes a rigid substrate, making it unsuitable for the production of flexible absorbers for both military and civilian applications. Textile materials, with their low density, lightness, porosity, flexible shape and structure, and excellent load-bearing properties, are ideal substrates for flexible absorbers. Textile-based absorbers, combining electromagnetic absorption properties with flexibility, have become the preferred choice for both military and civilian applications. However, their relatively weak absorption strength cannot meet the stealth requirements of battlefield environments. Absorbent fabrics hold significant value in enhancing the performance of electromagnetic shielding materials and promoting national defense security. Summary of the Invention

[0006] In response to the shortcomings of the above-mentioned existing technologies, a textile-based absorbing material with both electromagnetic wave absorption properties and flexibility, as well as a preparation method and application thereof are provided. A ZIF-67 / MXene composite-modified absorbing fabric is prepared by an impregnation process, and an effective composite of ZIF-67 and MXene is achieved using a flexible textile aramid fabric as a substrate. The composite material has the characteristics of flexibility, foldability, and lightness, and the absorbing performance of the composite material is improved by optimizing the impedance matching of the fabric.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is to prepare a textile-based absorbing material with both electromagnetic wave absorption properties and flexibility. The ZIF-67 modified absorbing fabric obtained by immersing the plasma-treated aramid fabric in a ZIF-67 solution, ultrasonically impregnating and drying it, is then immersed in a MXene solution, treated with an ultrasonic cleaner and then dried.

[0008] The above-mentioned textile-based absorbing material has both electromagnetic wave absorption characteristics and flexibility, which can be folded and bent at will, and has a gram weight of 120-350g / cm 2 .

[0009] The above-mentioned textile-based absorbing material having both electromagnetic wave absorption characteristics and flexibility has a thickness of 2.0 mm.

[0010] The above-mentioned textile-based absorbing material having both electromagnetic wave absorption properties and flexibility, wherein the MXene mass concentration is 2 mL / mg of MXene.

[0011] The above-mentioned textile-based absorbing material having both electromagnetic wave absorption characteristics and flexibility has an optimal reflection loss value of -20.10dB when the electromagnetic wave frequency is 9.376GHz.

[0012] The above-mentioned textile-based absorbing material, which has both electromagnetic wave absorption properties and flexibility, can adjust the number of times it is immersed in the MXene solution, and the reflection loss can achieve effective absorption in the frequency band within the range of 4.5-12.4 GHz.

[0013] The preparation method of the above-mentioned textile-based absorbing material having both electromagnetic wave absorption properties and flexibility comprises the following steps:

[0014] (1) Plasma treatment of aramid fabric using a vacuum plasma surface treatment system;

[0015] (2) Use a graduated cylinder to measure 10-12 mL of anhydrous methanol, weigh 0.3-0.5 g of Co(NO3)2·6H2O using an analytical balance, dissolve it in anhydrous methanol, and stir with a magnetic stirrer for 20-40 min to dissolve the solid;

[0016] (3) Use a measuring cylinder to measure 10-12 mL of anhydrous methanol, weigh 0.5-0.7 g of dimethylimidazole, dissolve it in anhydrous methanol, and stir rapidly with a magnetic stirrer for 20-40 minutes to dissolve the solid;

[0017] (4) Slowly add the methanol solution of dimethylimidazole to the methanol solution of Co(NO3)2·6H2O and magnetically stir for 1-2 h at room temperature to prepare a ZIF-67 solution;

[0018] (5) Immersing the aramid fabric in the stirred ZIF-67 solution and ultrasonically immersing it for 3-4 hours to prepare a ZIF-67-modified absorbing fabric, and drying the impregnated fabric in a drying oven;

[0019] (6) The aramid fabric impregnated with the ZIF-67 solution and dried is immersed in the MXene solution, treated with an ultrasonic cleaner for 10-20 minutes, and then placed in a drying oven for 1-2 hours to obtain a textile-based absorbing material with both electromagnetic wave absorption properties and flexibility.

[0020] The application of textile-based absorbing materials that have both electromagnetic wave absorption properties and flexibility is used in modern military equipment, especially electromagnetic wave absorption in stealth fighters.

[0021] The beneficial effects of the textile-based absorbing material with both electromagnetic wave absorption properties and flexibility of the present invention, as well as its preparation method and application are as follows: a ZIF-67 / MXene composite modified absorbing fabric is prepared by an impregnation process, and a flexible textile aramid fabric is used as a substrate to achieve effective compounding of ZIF-67 and MXene. The absorbing performance of the sample is tested, and finally an aramid absorbing fabric modified by ZIF-67 / MXene is successfully prepared. The composite material has the characteristics of flexibility, foldability, and lightness, and the absorbing performance of the composite material is improved by optimizing the impedance matching of the fabric.

[0022] A ZIF-67 solution was prepared via a liquid-phase diffusion method. This method is relatively simple, but requires careful control of stirring and resting time. A ZIF-67 / MXene-modified aramid absorbent fabric was successfully prepared. This method is a simple and environmentally friendly method for in-situ growth through impregnation. The ZIF-67 and MXene solutions were composited with aramid fabric, and its electromagnetic wave absorption properties were tested. The fabric exhibited excellent absorption performance. After three impregnations with 2 mL / mg of MXene and subsequent drying, the optimal reflection loss reached -20.10 dB at an electromagnetic wave frequency of 9.376 GHz. At this point, the absorbent material had a thickness of 2.0 mm. While the absorption efficiency is low, far below the ideal lightweight and efficient electromagnetic absorber, its thin thickness suggests that it possesses considerable application value. Furthermore, it was shown that by adjusting the number of MXene solution impregnations, the frequency band within which reflection loss effectively absorbs can be expanded to the 4.5-12.4 GHz range. Therefore, by adjusting the number of times of immersion in MXene solution, effective absorption of each frequency band can be achieved and applied to higher and wider environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 SEM images of the microstructure of original aramid fabric, MXene, loaded ZIF-67, and ZIF-67 / MXene original aramid fabric;

[0024] Figure 2 The reflection loss RL curve and impedance matching curve of sample 1# are shown;

[0025] Figure 3 The reflection loss RL curve and impedance matching curve of sample 2# are shown;

[0026] Figure 4 The reflection loss RL curve and impedance matching curve of sample 3#;

[0027] Figure 5 The reflection loss RL curve and impedance matching curve of sample 4#;

[0028] Figure 6 The reflection loss RL curve and impedance matching curve of sample 5#;

[0029] Figure 7 The reflection loss RL curve and impedance matching curve of sample 6#;

[0030] Figure 8 These are the reflection loss RL curve and impedance matching curve of sample 7#. DETAILED DESCRIPTION

[0031] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] The textile-based absorbing material with both electromagnetic wave absorption properties and flexibility is obtained by impregnating plasma-treated aramid fabric in a ZIF-67 solution, ultrasonically impregnating and drying it, and then impregnating it in a MXene solution, treating it with an ultrasonic cleaner and then drying it.

[0033] The above-mentioned textile-based absorbing material has both electromagnetic wave absorption characteristics and flexibility, which can be folded and bent at will, and has a gram weight of 120-350g / cm 2 .

[0034] The above-mentioned textile-based absorbing material having both electromagnetic wave absorption characteristics and flexibility has a thickness of 2.0 mm.

[0035] The above-mentioned textile-based absorbing material having both electromagnetic wave absorption properties and flexibility, wherein the MXene mass concentration is 2 mL / mg of MXene.

[0036] The above-mentioned textile-based absorbing material having both electromagnetic wave absorption characteristics and flexibility has an optimal reflection loss value of -20.10dB when the electromagnetic wave frequency is 9.376GHz.

[0037] The above-mentioned textile-based absorbing material, which has both electromagnetic wave absorption properties and flexibility, can adjust the number of times it is immersed in the MXene solution, and the reflection loss can achieve effective absorption in the frequency band within the range of 4.5-12.4 GHz.

[0038] Example 1

[0039] The preparation method of the above-mentioned textile-based absorbing material having both electromagnetic wave absorption properties and flexibility comprises the following steps:

[0040] The preparation method of the above-mentioned textile-based absorbing material having both electromagnetic wave absorption properties and flexibility comprises the following steps:

[0041] (1) Plasma treatment of aramid fabric using a vacuum plasma surface treatment system;

[0042] (2) Use a graduated cylinder to measure 10 mL of anhydrous methanol, weigh 0.3 g of Co(NO3)2·6H2O using an analytical balance, dissolve it in anhydrous methanol, and stir with a magnetic stirrer for 20 min to dissolve the solid;

[0043] (3) Use a graduated cylinder to measure 10 mL of anhydrous methanol, weigh 0.5 g of dimethylimidazole, dissolve it in anhydrous methanol, and stir rapidly with a magnetic stirrer for 20 min to dissolve the solid;

[0044] (4) Slowly add the methanol solution of dimethylimidazole to the methanol solution of Co(NO3)2·6H2O and magnetically stir for 1 h at room temperature to prepare a ZIF-67 solution;

[0045] (5) Immersing the aramid fabric in the stirred ZIF-67 solution and ultrasonically immersing it for 3 h to prepare a ZIF-67-modified absorbing fabric, and drying the impregnated fabric in a drying oven;

[0046] (6) The aramid fabric impregnated with the ZIF-67 solution and dried was immersed in the MXene solution, treated with an ultrasonic cleaner for 10 minutes, and then placed in a drying oven for 1 hour to obtain a textile-based absorbing material with both electromagnetic wave absorption properties and flexibility.

[0047] Example 2

[0048] The similarities between this embodiment and embodiment 1 are not repeated here. The difference between the present embodiment and embodiment 1 is that the method for preparing the above-mentioned textile-based absorbing material having both electromagnetic wave absorption properties and flexibility comprises the following steps:

[0049] The preparation method of the above-mentioned textile-based absorbing material having both electromagnetic wave absorption properties and flexibility comprises the following steps:

[0050] (1) Plasma treatment of aramid fabric using a vacuum plasma surface treatment system;

[0051] (2) Use a graduated cylinder to measure 11 mL of anhydrous methanol, weigh 0.4 g of Co(NO3)2·6H2O using an analytical balance, dissolve it in anhydrous methanol, and stir with a magnetic stirrer for 30 min to dissolve the solid;

[0052] (3) Use a graduated cylinder to measure 11 mL of anhydrous methanol, weigh 0.6 g of dimethylimidazole, dissolve it in anhydrous methanol, and stir rapidly with a magnetic stirrer for 30 min to dissolve the solid;

[0053] (4) Slowly add the methanol solution of dimethylimidazole to the methanol solution of Co(NO3)2·6H2O and magnetically stir for 1.5 h at room temperature to prepare a ZIF-67 solution;

[0054] (5) Immersing the aramid fabric in the stirred ZIF-67 solution and ultrasonically immersing it for 3.5 h to prepare a ZIF-67-modified absorbing fabric, and drying the impregnated fabric in a drying oven;

[0055] (6) The aramid fabric impregnated with the ZIF-67 solution and dried was immersed in the MXene solution, treated with an ultrasonic cleaner for 15 minutes, and then placed in a drying oven for 1.5 hours to obtain a textile-based absorbing material with both electromagnetic wave absorption properties and flexibility.

[0056] Example 3

[0057] The similarities between this embodiment and embodiment 1 are not repeated here. The difference between the present embodiment and embodiment 1 is that the method for preparing the above-mentioned textile-based absorbing material having both electromagnetic wave absorption properties and flexibility comprises the following steps:

[0058] The preparation method of the above-mentioned textile-based absorbing material having both electromagnetic wave absorption properties and flexibility comprises the following steps:

[0059] (1) Plasma treatment of aramid fabric using a vacuum plasma surface treatment system;

[0060] (2) Use a graduated cylinder to measure 12 mL of anhydrous methanol, weigh 0.5 g of Co(NO3)2·6H2O using an analytical balance, dissolve it in anhydrous methanol, and stir with a magnetic stirrer for 40 min to dissolve the solid;

[0061] (3) Use a graduated cylinder to measure 12 mL of anhydrous methanol, weigh 0.7 g of dimethylimidazole, dissolve it in anhydrous methanol, and stir rapidly with a magnetic stirrer for 40 min to dissolve the solid;

[0062] (4) Slowly add the methanol solution of dimethylimidazole to the methanol solution of Co(NO3)2·6H2O and magnetically stir for 2 h at room temperature to prepare a ZIF-67 solution;

[0063] (5) Immersing the aramid fabric in the stirred ZIF-67 solution and ultrasonically immersing it for 4 h to prepare a ZIF-67-modified absorbing fabric, and drying the impregnated fabric in a drying oven;

[0064] (6) The aramid fabric impregnated with the ZIF-67 solution and dried was immersed in the MXene solution, treated with an ultrasonic cleaner for 20 minutes, and then placed in a drying oven for 2 hours to obtain a textile-based absorbing material with both electromagnetic wave absorption properties and flexibility.

[0065] Example 4

[0066] (1) Aramid fabric was plasma treated using a vacuum plasma surface treatment system (Diener electronic Plasma-Surface-Technology GmbH+Co.KG, 120031, Nano-AL-PCCE) to improve the hydrophilicity of the fabric.

[0067] (2) Use a graduated cylinder to measure 11.3 mL of anhydrous methanol. Use an analytical balance to weigh 0.35 g of Co(NO3)2·6H2O and dissolve it in 11.3 mL of anhydrous methanol. Stir with a magnetic stirrer for 30 min to dissolve the solid.

[0068] (3) Use a measuring cylinder to measure 11.3 mL of anhydrous methanol, weigh 0.66 g of dimethylimidazole, dissolve it in 11.3 mL of anhydrous methanol, and stir rapidly with a magnetic stirrer for 30 minutes to dissolve the solid.

[0069] (4) The methanol solution of dimethylimidazole was slowly added to the methanol solution of Co(NO3)2·6H2O and magnetically stirred at room temperature for 1 h to prepare a ZIF-67 solution.

[0070] (5) Cut seven aramid fabric samples of equal size and immerse six of them in the stirred ZIF-67 solution. Ultrasonic immersion was performed for 3 h to prepare ZIF-67-modified absorbing fabrics. The impregnated fabrics were dried in a drying oven. The remaining fabric was used as a control fabric impregnated only with MXene.

[0071] (6) The five aramid fabrics impregnated with ZIF-67 solution and dried were immersed in 2 mg / mL MXene solution for 1, 2, 3, 4, and 5 times, respectively. Each time, they were treated with an ultrasonic cleaner for 10 minutes. After each treatment, they were placed in a drying oven and dried for 1 hour. They were numbered 3#, 4#, 5#, 6#, and 7# respectively. Among them, the original aramid fabric was directly immersed in the MXene solution once, treated with an ultrasonic cleaner for 10 minutes and dried. The sample numbered 2# was used as the control group. The sample that was only immersed in the ZIF-67 solution was numbered 1#. After the above experiments, 7 fabric samples were obtained, namely: 1#, 2#, 3#, 4#, 5#, 6#, and 7#.

[0072] Microstructure characterization

[0073] Figure 1 SEM images of the micromorphology of pristine aramid fabric, MXene-loaded ZIF-67, and ZIF-67 / MXene pristine aramid fabric. The modified fabrics retain their original fiber shape. The SEM micromorphology reveals the microscopic morphology of ZIF-67 particles loaded onto the fabric fiber surface. This morphology enhances electromagnetic wave propagation through the material and optimizes impedance matching, thereby improving the fabric's microwave absorption performance.

[0074] Wave absorbing performance

[0075] The electromagnetic parameters of the fabric were tested using a vector network analyzer under the waveguide method. The prepared composite fabric was cut into 25mm×40mm and clamped into an 8.2-12.4GHz waveguide fixture. Its electromagnetic parameters in the X-band were tested, and the absorption performance of the modified fabric was further calculated based on the electromagnetic parameters.

[0076] Complex magnetic permeability, in the frequency range of 8.2-12.4 GHz, the five samples have similar trends, which indicates that their electromagnetic storage capabilities are almost similar. X (MXene used in this application) does not have magnetic loss capability. The magnetism of the sample mainly comes from the Co particles loaded between layers and on the surface. Therefore, and have low values ​​and are almost equal to 1 and 0.

[0077] like Figure 2 As shown, the sample is an aramid fabric immersed in a single ZIF-67 solution. It can be seen that its reflection loss is all above -10dB, and effective absorption is not achieved. This proves that modification with a single ZIF-67 solution cannot meet the requirements for preparing modified absorbing fabrics.

[0078] like Figure 3 As shown in the figure, the sample is a single aramid fabric impregnated with MXene solution. It can be seen that its reflection loss is only as low as -12.34dB when the thickness is 1mm and the frequency is 10.89GHz, which proves that the single MXene solution modification is better than the single ZIF-67 solution modification, but it still cannot meet the requirements for preparing modified absorbing fabrics.

[0079] like Figure 4 The sample shown is a ZIF-67 / MXene composite-modified absorbing aramid fabric (sample 3), and the changes in RL and characteristic impedance Z of the sample with frequency. It can be seen that RL represents the reflection loss of the composite material to microwaves. The smaller the value, the stronger the material's ability to absorb microwaves. The characteristic impedance Z is a parameter that combines the dielectric constant and magnetic permeability of the material. As can be seen from the figure, within the frequency range, when the sample thickness is 5.5mm, the RL value of the composite material is low and the characteristic impedance Z is relatively large, indicating that the composite material has good absorbing performance at this thickness. It is proved that the prepared ZIF-67 / MXene composite-modified absorbing aramid fabric has better absorbing performance than the fabric modified with a single MXene solution or a single ZIF-67 solution.

[0080] like Figure 5 As shown in the figure, this sample is a ZIF-67 / MXene composite modified aramid fabric (sample 4). It can be seen that its reflection loss reaches a minimum of -15.65dB at a thickness of 2mm and a frequency of 8.87GHz. This proves that with increasing MXene impregnation times, the absorption bandwidth of its reflection loss increases, further improving its absorbing performance. As can be seen from the figure, at thicknesses of 2mm and 1.5mm, its impedance matching can fluctuate around 1, basically achieving the excellent absorbing properties of the composite material. Therefore, the prepared composite absorbing fabric can basically meet the requirements for preparing modified absorbing fabrics.

[0081] like Figure 6 As shown in the figure, this sample is a ZIF-67 / MXene composite modified absorbing aramid fabric (5#). It can be seen that its reflection loss reaches a minimum of -21.34dB at a thickness of 2mm and a frequency of 9.26GHz, proving that with increasing MXene impregnation times, its optimal reflection loss value decreases, and the effective absorption bandwidth reaches 3.7GHz, further improving the absorbing performance. Similar to sample 4#, its impedance matching fluctuates around 1 at thicknesses of 2mm and 1.5mm, basically achieving the excellent absorbing properties of the composite material. Therefore, the prepared composite absorbing fabric can basically meet the requirements for preparing modified absorbing fabrics.

[0082] like Figure 7 As shown in the figure, the sample is a ZIF-67 / MXene composite modified absorbing aramid fabric (6#). It can be seen that its reflection loss reaches a minimum of -14.96dB at a thickness of 5.5mm and a frequency of 10.76GHz. This proves that with the increase in the number of MXene impregnations, its effective absorption bandwidth and minimum reflection loss do not increase, but decrease instead. At thicknesses of 2.5mm and 1.5mm, its impedance matching basically fluctuates around 1. Therefore, the prepared composite absorbing fabric can basically meet the requirements for preparing modified absorbing fabrics.

[0083] like Figure 8 As shown in the figure, the sample is a ZIF-67 / MXene composite modified absorbing aramid fabric (7#). It can be seen that when the thickness is 2.5 mm, its reflection loss is relatively wide, and can reach 1.24 GHz. This proves that with the increase of the number of MXene immersion times, its effective absorption bandwidth and minimum reflection loss deteriorate. Therefore, the absorbing performance of the composite electromagnetic wave absorbing fabric does not become more superior with the increase of the number of immersion in MXene solution.

[0084] The excellent microwave absorption performance of the composite material is primarily due to the following factors: First, ZIF-67 and MXene have high dielectric constants and magnetic permeabilities, which enable them to effectively absorb and scatter microwave signals, resulting in strong dielectric and magnetic losses within the microwave frequency range. Second, the layered structure and interfacial interactions cause multiple reflections and scattering, preventing the transmission of microwave signals through the material, thereby improving the material's microwave absorption performance. In addition, the interfacial polarization phenomenon between ZIF-67 and MXene also contributes to the material's microwave absorption performance. In summary, the prepared ZIF-67 and MXene composite absorbing fabric has excellent microwave absorption performance and can meet the application requirements of modified microwave absorbing fabrics.

[0085] In this application, a ZIF-67 / MXene composite modified absorbing fabric was prepared through an impregnation process, and a flexible textile aramid fabric was used as the substrate to achieve an effective composite of ZIF-67 and MXene. The absorbing performance of the sample was tested, and finally an aramid absorbing fabric modified by ZIF-67 / MXene was successfully prepared. The composite material has the characteristics of flexibility, foldability, and lightweight, and the absorbing performance of the composite material is improved by optimizing the impedance matching of the fabric.

[0086] A ZIF-67 solution was prepared using the liquid-phase diffusion method. This method is relatively simple to use, but requires careful control of stirring and resting time. This method successfully produced ZIF-67 / MXene-modified aramid absorbing fabric. This is a simple and environmentally friendly method for in-situ growth through impregnation. The ZIF-67 and MXene solutions were composited with aramid fabric and their electromagnetic wave absorption properties were tested. The resulting absorbing fabric exhibited excellent absorption performance. The fabric impregnated with ZIF-67 alone exhibited the worst absorption loss, with the maximum reflection loss value failing to achieve effective absorption. This also indirectly reflects the poor absorption performance of MXene and ZIF-67 alone. The performance of the absorbing fabrics prepared by combining ZIF-67 and MXene is improved compared to those prepared by using only MXene and ZIF-67. After being immersed in 2mL / mg of MXene three times and dried, the sample has an optimal reflection loss value of -20.10dB at an electromagnetic wave frequency of 9.376GHz. The thickness of the absorbing material at this time is 2.0mm. Although the absorption efficiency is low and there is a certain gap with the ideal lightweight and efficient electromagnetic absorbing material, it is thin and can be said to have certain application value. In addition, it can be seen that by adjusting the number of times of immersion in the MXene solution, the frequency band in which the reflection loss reaches effective absorption can be expanded to the range of 4.5-12.4GHz. Therefore, by adjusting the number of times of immersion in the MXene solution, effective absorption of each frequency band can be achieved, and it can be applied to higher and wider environments.

[0087] Example 8

[0088] The application of textile-based absorbing materials that combine electromagnetic wave absorption properties with flexibility. Textile-based absorbing materials that combine electromagnetic wave absorption properties with flexibility are flexible, foldable, and lightweight. By optimizing the impedance matching of the fabric, the absorbing performance of the composite material is improved. They can be applied to modern military equipment, especially stealth fighters, for electromagnetic absorption.

[0089] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention should also fall within the scope of protection of the present invention.

Claims

1. A textile-based absorbing material having both electromagnetic wave absorption properties and flexibility, characterized by: The ZIF-67 modified absorbing fabric is obtained by impregnating the plasma-treated aramid fabric in a ZIF-67 solution, ultrasonically impregnating and drying it, and then impregnating it in a MXene solution, treating it with an ultrasonic cleaner and then drying it; The preparation process of the ZIF-67 solution is as follows: 10-12 mL of anhydrous methanol is measured with a measuring cylinder, 0.3-0.5 g of Co(NO3)2·6H2O is weighed on an analytical balance, and the mixture is dissolved in anhydrous methanol, and stirred with a magnetic stirrer for 20-40 minutes to dissolve the solid; 10-12 mL of anhydrous methanol is measured with a measuring cylinder, 0.5-0.7 g of dimethylimidazole is weighed, and the mixture is dissolved in anhydrous methanol, and the mixture is rapidly stirred with a magnetic stirrer for 20-40 minutes to dissolve the solid; the methanol solution of dimethylimidazole is slowly added to the methanol solution of Co(NO3)2·6H2O, and the mixture is magnetically stirred for 1-2 hours at room temperature to prepare a ZIF-67 solution; When the MXene mass concentration is 2 mL / mg and the thickness is 2.0 mm, the optimal reflection loss value is -20.10 dB when the electromagnetic wave frequency is 9.376 GHz.

2. The textile-based absorbing material having both electromagnetic wave absorption properties and flexibility according to claim 1, characterized in that: It can be folded and bent at will, and its weight is 120-350g / m².

3. The method for preparing the textile-based absorbing material having both electromagnetic wave absorption properties and flexibility according to any one of claims 1 to 2, characterized in that: The steps include: (1) Plasma treatment of aramid fabric using a vacuum plasma surface treatment system; (2) Use a measuring cylinder to measure 10-12 mL of anhydrous methanol, weigh 0.3-0.5 g of Co(NO3)2·6H2O on an analytical balance, dissolve it in anhydrous methanol, and stir with a magnetic stirrer for 20-40 minutes to dissolve the solid; (3) Use a measuring cylinder to measure 10-12 mL of anhydrous methanol, weigh 0.5-0.7 g of dimethylimidazole, dissolve it in anhydrous methanol, and stir rapidly with a magnetic stirrer for 20-40 minutes to dissolve the solid; (4) Slowly add the methanol solution of dimethylimidazole to the methanol solution of Co(NO3)2·6H2O and magnetically stir at room temperature for 1-2 h to prepare a ZIF-67 solution; (5) Immerse the aramid fabric in the stirred ZIF-67 solution and ultrasonically immerse it for 3-4 hours to prepare a ZIF-67-modified absorbing fabric, and dry the impregnated fabric in a drying oven; (6) The aramid fabric impregnated with the ZIF-67 solution and dried is immersed in the MXene solution, treated with an ultrasonic cleaner for 10-20 minutes, and then placed in a drying oven for 1-2 hours to obtain a textile-based absorbing material with both electromagnetic wave absorption properties and flexibility.

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