Anti-interference wave-absorbing copper foil applied to low-altitude aircraft and preparation method of anti-interference wave-absorbing copper foil

Abstract

The invention provides an anti-interference wave-absorbing copper foil applied to a low-altitude aircraft and a preparation method of the anti-interference wave-absorbing copper foil. The anti-interference wave-absorbing copper foil applied to the low-altitude aircraft comprises two copper foil layers and an electromagnetic shielding layer, the electromagnetic shielding layer is arranged between the two copper foil layers, the electromagnetic shielding layer is made of carbon fiber grafted titanium carbide MXene, and the electromagnetic shielding layer and the copper foil layers are bonded through high-temperature-resistant resin; the electromagnetic shielding layer and the copper foil are prepared into the copper foil plate through a hot pressing / laminating composite process, and the copper foil plate has excellent electromagnetic shielding performance, light weight and structural stability when applied to low-altitude aircrafts.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic shielding materials technology, specifically relating to an anti-interference absorbing copper foil for use in low-altitude aircraft and its preparation method. Background Technology

[0002] Low-altitude aircraft (such as drones and light helicopters) are increasingly used in civilian surveying, power line inspection, and military reconnaissance. However, their operating environment is subject to complex electromagnetic interference (such as interference from ground communication signals, navigation frequency bands, and electromagnetic radiation), which can easily lead to control system malfunctions and communication interruptions, seriously affecting flight safety. Current electromagnetic protection for low-altitude aircraft often uses a single copper foil as the shielding material, relying on its high conductivity to reflect electromagnetic waves. However, this method has the following drawbacks: first, it relies solely on reflection, resulting in weak absorption of electromagnetic waves and a narrow anti-interference bandwidth; second, the bonding strength between the copper foil and the substrate is poor, making it prone to delamination under vibration, high and low temperature cycling, and other conditions; and third, it is not lightweight enough, increasing the aircraft's energy consumption.

[0003] MXene, with its two-dimensional layered structure and high electrical conductivity, possesses both electromagnetic wave absorption and reflection properties, making it an ideal electromagnetic shielding reinforcement. Combining it with carbon fiber creates a high-strength, high-shielding composite material. Carbon fiber, as a high-strength, lightweight material, has a density of 1.7-2.0 g / cm³. 3 With a tensile strength >3GPa, MXene is often used as a carrier and is a good material for constructing composite structures. However, existing MXene / carbon fiber and copper foil composite technologies still have the following problems: First, the interfacial compatibility between MXene and carbon fiber is poor. Unmodified MXene is difficult to disperse evenly due to differences in surface energy, resulting in the formation of conductive islands inside the composite material, which weakens the continuity of the shielding network. Second, the bonding method between copper foil and the composite shielding layer is unreasonable. Traditional physical pressing or ordinary resin bonding is prone to reducing shielding effectiveness due to excessive interfacial resistance, and the temperature resistance is insufficient (glass transition temperature <100℃), which cannot adapt to the thermal environment of the cabin of low-altitude aircraft. Third, the composite process lacks targeted design and does not consider the special requirements of low-altitude aircraft for material thickness (usually <500μm), flexibility, and weather resistance, resulting in excessively rapid performance degradation in practical applications.

[0004] Existing research on electromagnetic shielding materials often focuses on improving a single performance, such as high shielding effectiveness, while neglecting the synergistic optimization of shielding, mechanics, and lightweighting. For example, Chinese patent CN119913582A discloses a silver-gray electromagnetic shielding copper foil, which improves shielding performance through alloy plating but does not introduce a wave absorption mechanism, resulting in limited anti-interference bandwidth. CN209619969U uses a composite of multi-layer rubber pads and copper foil, which improves flexibility but significantly increases density and is prone to aging at high temperatures.

[0005] Therefore, developing an anti-interference material that uses copper foil as a reflective layer, MXene / carbon fiber as an absorbing layer, and achieves stable composite structure through a high-temperature resistant adhesive has become an urgent need to solve the electromagnetic compatibility problem of low-altitude aircraft. Summary of the Invention

[0006] Purpose of the invention:

[0007] The purpose of this invention is to provide an anti-interference absorbing copper foil for use in low-altitude aircraft and its preparation method, which solves the problems of poor anti-interference effect, insufficient structural stability and poor lightweight of existing shielding materials, and achieves synergistic optimization of high shielding effectiveness, strong bonding force and lightweight.

[0008] The technical solution of this invention:

[0009] The present invention provides an anti-interference absorbing copper foil for use in low-altitude aircraft. The anti-interference absorbing copper foil for use in low-altitude aircraft includes two copper foil layers and an electromagnetic shielding layer, wherein the electromagnetic shielding layer is sandwiched between the two copper foil layers; the electromagnetic shielding layer and the copper foil layers are bonded and fixed together by high-temperature resistant resin.

[0010] Furthermore, the electromagnetic shielding layer is made of carbon fiber grafted titanium carbide MXene.

[0011] Furthermore, the method for preparing the electromagnetic shielding layer includes the following steps:

[0012] S1: Add titanium carbide MXene to anhydrous ethanol, adjust the pH to 4-5 with acetic acid solution, slowly add 3-aminopropyltriethoxysilane, react at 60-70℃ under ultrasonic conditions for 4-6 hours, after the reaction is completed, wash with anhydrous ethanol and deionized water, and vacuum dry the precipitate to obtain titanium carbide MXene-NH2.

[0013] S2: At room temperature, carbon fiber is soaked in acetone solution for 64-72 hours, then washed with deionized water and dried under vacuum to obtain pretreated carbon fiber. Then, the pretreated carbon fiber is soaked in nitric acid, heated to 80-90℃, reacted for 3-5 hours, washed with deionized water, and dried under vacuum to obtain oxidized carbon fiber.

[0014] S3: Add the titanium carbide MXene-NH2 and HATU powder prepared in step S1 to DMF solvent, sonicate until uniformly dispersed, then add the carbon oxide prepared in step S2 to completely impregnate and sonicate, react at 60-70℃ for 4-6 hours, wash with deionized water after the reaction, and vacuum dry to obtain carbon fiber grafted with titanium carbide MXene, i.e. the electromagnetic shielding layer.

[0015] Furthermore, the solid-liquid ratio of the titanium carbide MXene to anhydrous ethanol is 1g:100-150ml.

[0016] Furthermore, the concentration of the nitric acid is 65-70 wt%, and the liquid-solid ratio of the nitric acid to the pretreated carbon fiber is 10-20 mL: 1 g.

[0017] Furthermore, the mass ratio of the oxidized carbon fiber to titanium carbide MXene-NH2 is 1:0.05-0.2.

[0018] This invention also provides a method for preparing anti-interference absorbing copper foil for use in low-altitude aircraft, characterized by comprising the following steps:

[0019] (1) Pretreatment: Roughen the surface of the copper foil;

[0020] (2) Lamination: Apply high-temperature resistant resin between the electromagnetic shielding layer and the copper foil layer, and then stack them in the order of copper foil layer-electromagnetic shielding layer-copper foil layer to obtain a laminated structure.

[0021] (3) Hot pressing composite: The laminated structure is placed in a laminator and a temperature of 100-300℃ and a pressure of 1-10MPa are applied to make the layers tightly bonded and remove air bubbles, so as to obtain an anti-interference absorbing copper foil board.

[0022] Furthermore, the surface roughening treatment of the copper foil adopts an electrochemical roughening method, and the roughness Ra of the copper foil surface after roughening is 0.5-2.0μm; in step (3), the heat preservation and pressure preservation time of hot pressing composite is 30-60min.

[0023] Furthermore, the high-temperature resistant resin is one of bisphenol A cyanate, o-cresol epoxy resin, and epoxy resin F-51; the coating thickness of the high-temperature resistant resin is 50-300 μm.

[0024] Furthermore, the thickness of the copper foil layer is 10-50 μm, and the thickness of the electromagnetic shielding layer is 50-200 μm.

[0025] The outer copper foil (highly conductive) reflects most of the incident electromagnetic waves (especially high-frequency waves), reducing penetration. In the middle electromagnetic shielding layer, carbon fiber-grafted titanium carbide MXene forms a continuous conductive network with a two-dimensional layered structure, absorbing residual electromagnetic waves through interface polarization and eddy current losses (caused by high conductivity). The inner copper foil further reflects unabsorbed electromagnetic waves, forming a closed-loop attenuation of "reflection-absorption-rereflection," significantly improving shielding effectiveness. The electromagnetic shielding layer uses low-density carbon fiber (1.7-2.0 g / cm³). 3 Using MXene as the matrix, the density after composite formation is still below 3.0 g / cm³. 3Combined with a thin design (total thickness ≤500μm), the overall weight is significantly reduced; the bonding resin is selected with a high Tg (>100℃) variety, whose molecular chain rigidity and temperature resistance are suitable for the cabin thermal environment of low-altitude aircraft, avoiding the degradation of shielding performance caused by bonding failure at high temperatures.

[0026] Beneficial effects:

[0027] This invention discloses an anti-interference absorbing copper foil for low-altitude aircraft and its preparation method. It employs a double-layer copper foil + carbon fiber-grafted titanium carbide MXene shielding layer structure to achieve high shielding efficiency of 45-62dB in the X-band. Utilizing a "reflection-absorption-rereflection" mechanism, it provides highly efficient anti-interference. The electrochemical roughening combined with a high-Tg bonding resin results in high interface strength, maintaining over 95% performance retention after 1000 thermal cycles. It also features a lightweight design (density ≤3.5g / cm³). 3 It is suitable for aircraft requirements, has excellent high-temperature stability, maintains over 95% shielding effectiveness at 200℃, and is compatible with existing production systems, making it highly valuable for applications. Detailed Implementation

[0028] The present invention will be described below with reference to specific embodiments. It should be noted that the following embodiments are examples of the present invention and are used only to illustrate the invention, not to limit it. Other combinations and various modifications within the scope of the present invention can be made without departing from its spirit or scope.

[0029] Unless otherwise specified, all chemical reagents used in this invention are commercially available analytical grade reagents; among them, MAX phase Ti3AlC2: 400 mesh, Foshan Xinxi Technology Co., Ltd.; anhydrous lithium chloride (purity 99%): analytical grade, Maclean Biochemical Technology Co., Ltd.; O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethylureonium hexafluorophosphate (HATU, purity 99%): Shanghai Aladdin Biochemical Technology Co., Ltd.; carbon fiber T700; copper foil thickness 30μm; laminator, model LD-300; electrochemical roughening equipment, model EC-200.

[0030] Preparation of titanium carbide MXene:

[0031] S1: Prepare a mixed acid solution by sequentially adding 20 mL of hydrofluoric acid, 20 mL of hydrochloric acid and 10 mL of deionized water to a 100 mL polytetrafluoroethylene beaker. After heating to 35 °C, slowly add 2 g of MAX phase Ti3AlC2 powder and continue the reaction at 600 r / min for 24 h. After the reaction is completed, wash the acid with deionized water by centrifugation until the pH of the supernatant is ≥6, leaving the bottom precipitate.

[0032] S2: Dissolve 2g of lithium chloride powder in 40mL of deionized water, add the precipitate at the bottom of step S1 and shake well. Stir at room temperature for 24h and remove lithium chloride by centrifugation with deionized water. Filter and dry to obtain titanium carbide MXene.

[0033] Preparation of electromagnetic shielding layer A:

[0034] S1: Add 5g of titanium carbide MXene to 750ml of anhydrous ethanol, adjust the pH to 4 with acetic acid solution, slowly add 8g of 3-aminopropyltriethoxysilane, react at 60℃ for 4 hours under ultrasonic conditions, after the reaction is completed, wash with anhydrous ethanol and deionized water, and dry the precipitate under vacuum at 60℃ for 8 hours to obtain titanium carbide MXene-NH2.

[0035] S2: At room temperature, 20g of carbon fiber was soaked in 500mL of acetone solution for 72h, washed with deionized water until no acetone residue was left in the filtrate, and vacuum dried at 60℃ for 6h to obtain pretreated carbon fiber. 10g of pretreated carbon fiber was taken, 150mL of 68% nitric acid (liquid-solid ratio 15mL:1g) was added, and the mixture was heated to 80℃ for 4h. The mixture was washed with deionized water until the pH of the filtrate was 7, and vacuum dried at 60℃ for 6h to obtain oxidized carbon fiber.

[0036] S3: Add 1g of titanium carbide MXene-NH2 and 1g of HATU powder prepared in step S1 to 500ml of DMF solvent, and ultrasonically disperse for 30min until uniform. Then add 10g of carbon oxide prepared in step S2, and continue ultrasonication for 30min after complete impregnation. React at 60℃ for 4h. After the reaction is completed, wash with deionized water and vacuum dry at 60℃ for 8h to obtain carbon fiber grafted with titanium carbide MXene, which is the electromagnetic shielding layer A.

[0037] Preparation of electromagnetic shielding layer B:

[0038] S1: Add 5g of titanium carbide MXene to 750ml of anhydrous ethanol, adjust the pH to 4 with acetic acid solution, slowly add 8g of 3-aminopropyltriethoxysilane, react at 60℃ for 4 hours under ultrasonic conditions, after the reaction is completed, wash with anhydrous ethanol and deionized water, and dry the precipitate under vacuum at 60℃ for 8 hours to obtain titanium carbide MXene-NH2.

[0039] S2: At room temperature, 20g of carbon fiber was soaked in 500mL of acetone solution for 72h, washed with deionized water until no acetone residue was left in the filtrate, and vacuum dried at 60℃ for 6h to obtain pretreated carbon fiber. 10g of pretreated carbon fiber was taken, 150mL of 68% nitric acid (liquid-solid ratio 15mL:1g) was added, and the mixture was heated to 80℃ for 4h. The mixture was washed with deionized water until the pH of the filtrate was 7, and vacuum dried at 60℃ for 6h to obtain oxidized carbon fiber.

[0040] S3: Add 0.5g of titanium carbide MXene-NH2 and 0.5g of HATU powder prepared in step S1 to 500ml of DMF solvent, and ultrasonically disperse for 30min until uniform. Then add 10g of carbon oxide prepared in step S2, and continue ultrasonication for 30min after complete impregnation. React at 60℃ for 4h. After the reaction is completed, wash with deionized water and vacuum dry at 60℃ for 8h to obtain carbon fiber grafted with titanium carbide MXene, which is the electromagnetic shielding layer B.

[0041] Preparation of electromagnetic shielding layer C:

[0042] S1: Add 5g of titanium carbide MXene to 750ml of anhydrous ethanol, adjust the pH to 4 with acetic acid solution, slowly add 8g of 3-aminopropyltriethoxysilane, react at 60℃ for 4 hours under ultrasonic conditions, after the reaction is completed, wash with anhydrous ethanol and deionized water, and dry the precipitate under vacuum at 60℃ for 8 hours to obtain titanium carbide MXene-NH2.

[0043] S2: At room temperature, 20g of carbon fiber was soaked in 500mL of acetone solution for 72h, washed with deionized water until no acetone residue was left in the filtrate, and vacuum dried at 60℃ for 6h to obtain pretreated carbon fiber. 10g of pretreated carbon fiber was taken, 150mL of 68% nitric acid (liquid-solid ratio 15mL:1g) was added, and the mixture was heated to 80℃ for 4h. The mixture was washed with deionized water until the pH of the filtrate was 7, and vacuum dried at 60℃ for 6h to obtain oxidized carbon fiber.

[0044] S3: Add 2g of titanium carbide MXene-NH2 and 2g of HATU powder prepared in step S1 to 500ml of DMF solvent, and ultrasonically disperse for 30min until uniform. Then add 10g of carbon oxide prepared in step S2, and continue ultrasonication for 30min after complete impregnation. React at 60℃ for 4h. After the reaction is completed, wash with deionized water and vacuum dry at 60℃ for 8h to obtain carbon fiber grafted with titanium carbide MXene, which is the electromagnetic shielding layer C.

[0045] Example 1

[0046] (1) Pretreatment: The surface of the copper foil is roughened by electrochemical roughening to Ra 1.0 μm;

[0047] (2) Stacking: Apply 150 μm of bisphenol A cyanate between electromagnetic shielding layer A and copper foil layer, 30 μm of copper foil layer, 100 μm of electromagnetic shielding layer, and 30 μm of copper foil layer, and then stack them in the order of copper foil layer-electromagnetic shielding layer-copper foil layer to obtain a stacked structure.

[0048] (3) Hot pressing composite: The laminated structure is placed in a laminator, and a temperature of 200℃ and a pressure of 5MPa are applied. The temperature is maintained for 45 minutes to make the layers tightly bonded and remove air bubbles, thus obtaining an anti-interference absorbing copper foil board.

[0049] Example 2

[0050] (1) Pretreatment: The surface of the copper foil is roughened by electrochemical roughening to Ra 1.0 μm;

[0051] (2) Stacking: Apply epoxy resin F-51 50μm between electromagnetic shielding layer B and copper foil layer, copper foil layer 10μm, electromagnetic shielding layer 50μm, copper foil layer 10μm, and then stack them in the order of copper foil layer-electromagnetic shielding layer-copper foil layer to obtain a stacked structure.

[0052] (3) Hot pressing composite: The laminated structure is placed in a laminator, and a temperature of 100°C and a pressure of 1MPa are applied. The temperature is maintained for 30 minutes to make the layers tightly bonded and remove air bubbles, thus producing an anti-interference absorbing copper foil board.

[0053] Example 3

[0054] (1) Pretreatment: The surface of the copper foil is roughened by electrochemical roughening to Ra 1.0 μm;

[0055] (2) Lamination: Apply 300μm of o-cresol epoxy resin, 50μm of copper foil layer, 200μm of electromagnetic shielding layer, and 50μm of copper foil layer between electromagnetic shielding layer C and copper foil layer. Then, stack them in the order of copper foil layer-electromagnetic shielding layer-copper foil layer to obtain the laminated structure.

[0056] (3) Hot pressing composite: The laminated structure is placed in a laminator, and a temperature of 300℃ and a pressure of 10MPa are applied. The temperature is maintained for 60 minutes to make the layers tightly bonded and remove air bubbles, thus obtaining an anti-interference absorbing copper foil board.

[0057] Comparative Example 1

[0058] (1) Pretreatment: The surface of the copper foil is roughened by electrochemical roughening to Ra 1.0 μm;

[0059] (2) Lamination: Apply epoxy resin E51 150μm between electromagnetic shielding layer A and copper foil layer, copper foil layer 30μm, electromagnetic shielding layer 100μm, copper foil layer 30μm, and then stack them in the order of copper foil layer-electromagnetic shielding layer-copper foil layer to obtain the laminated structure.

[0060] (3) Hot pressing composite: The laminated structure is placed in a laminator, and a temperature of 200℃ and a pressure of 5MPa are applied. The temperature is maintained for 45 minutes to make the layers tightly bonded and remove air bubbles, thus obtaining an anti-interference absorbing copper foil board.

[0061] Comparative Example 2

[0062] Add 1g of MAX phase Ti3AlC2 powder and 1g of HATU to 500ml of DMF, disperse by ultrasonication, add 10g of carbon fiber, and react at 60℃ for 4h to obtain an electromagnetic shielding layer.

[0063] (1) Pretreatment: The surface of the copper foil is roughened by electrochemical roughening to Ra 1.0 μm;

[0064] (2) Stacking: Apply 150 μm of bisphenol A cyanate between the electromagnetic shielding layer and the copper foil layer, 30 μm of copper foil layer, 100 μm of electromagnetic shielding layer, and 30 μm of copper foil layer, and then stack them in the order of copper foil layer-electromagnetic shielding layer-copper foil layer to obtain a stacked structure.

[0065] (3) Hot pressing composite: The laminated structure is placed in a laminator, and a temperature of 200℃ and a pressure of 5MPa are applied. The temperature is maintained for 45 minutes to make the layers tightly bonded and remove air bubbles, thus obtaining an anti-interference absorbing copper foil board.

[0066] Comparative Example 3

[0067] (1) Pretreatment: The surface of the copper foil is roughened by electrochemical roughening to Ra 1.0 μm;

[0068] (2) Stacking: Apply 150 μm of bisphenol A cyanate between electromagnetic shielding layer A and copper foil layer, 30 μm of copper foil layer, 100 μm of electromagnetic shielding layer, and 30 μm of copper foil layer, and then stack them in the order of copper foil layer-electromagnetic shielding layer-copper foil layer to obtain a stacked structure.

[0069] (3) Hot pressing composite: The laminated structure is placed in a laminator, and a temperature of 145℃ and a pressure of 5MPa are applied. The temperature is maintained for 45 minutes to make the layers tightly bonded and remove air bubbles, thus obtaining an anti-interference absorbing copper foil board.

[0070] Performance testing experiments:

[0071] 1. Electromagnetic shielding effectiveness (SE): Tested using a vector network analyzer in the X-band (8-12GHz), with a sample size of 22.86mm × 10.16mm.

[0072] 2. Bond strength: Refer to GB / T 7124-2008 to test the tensile shear strength between the copper foil and the electromagnetic shielding layer;

[0073] 3. Environmental resistance: After 1000 cycles of thermal cycling from -50℃ to 150℃, the structural integrity was observed and the SE retention rate was tested.

[0074] Table 1: Test Results Table

[0075]

[0076] As shown in the table above, the anti-interference absorbing copper foils prepared in Examples 1-3 for use in low-altitude aircraft, when matched with suitable bonding resins and hot-pressing parameters, achieve shielding effectiveness of 45-62dB and interfacial bonding strength of 10.2-13.8MPa. Furthermore, they exhibit high performance retention after thermal cycling and high-temperature testing, demonstrating the synergistic advantages of "high shielding + strong bonding + environmental resistance." Among these, Example 3 demonstrates the best performance due to the superior high-temperature resistance of o-cresyl epoxy resin and its thicker electromagnetic shielding layer. Comparative Example 1, with its insufficient high-temperature resistance of epoxy resin E51 (Tg≈120℃), suffers from significant attenuation in shielding effectiveness and bonding strength at high temperatures. Comparative Example 2, using the MAX phase directly (not etched to MXene), fails to form an effective conductive network, resulting in a shielding effectiveness of only 30dB and weak bonding with carbon fiber, leading to easy delamination. Comparative Example 3, with its hot-pressing temperature (145℃) lower than the curing threshold of bisphenol A cyanate (≈200℃), suffers from incomplete curing, resulting in numerous interlayer defects and a comprehensive performance decline.

[0077] This invention can also be implemented in various other ways. Without departing from the spirit and essence of this invention, those skilled in the art can make various corresponding changes and modifications according to this invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. An anti-interference absorbing copper foil for use in low-altitude aircraft, characterized in that, The anti-interference absorbing copper foil used in low-altitude aircraft comprises two copper foil layers and an electromagnetic shielding layer, wherein the electromagnetic shielding layer is sandwiched between the two copper foil layers; the electromagnetic shielding layer and the copper foil layers are bonded and fixed together by high-temperature resistant resin.

2. The anti-interference absorbing copper foil for low-altitude aircraft according to claim 1, characterized in that, The electromagnetic shielding layer is made of carbon fiber grafted titanium carbide MXene.

3. The anti-interference absorbing copper foil for low-altitude aircraft according to claim 2, characterized in that, The method for preparing the electromagnetic shielding layer includes the following steps: S1: Add titanium carbide MXene to anhydrous ethanol, adjust the pH to 4-5 with acetic acid solution, slowly add 3-aminopropyltriethoxysilane, react at 60-70℃ under ultrasonic conditions for 4-6 hours, after the reaction is completed, wash with anhydrous ethanol and deionized water, and vacuum dry the precipitate to obtain titanium carbide MXene-NH2. S2: At room temperature, carbon fiber is soaked in acetone solution for 64-72 hours, then washed with deionized water and dried under vacuum to obtain pretreated carbon fiber. Then, the pretreated carbon fiber is soaked in nitric acid, heated to 80-90℃, reacted for 3-5 hours, washed with deionized water, and dried under vacuum to obtain oxidized carbon fiber. S3: Add the titanium carbide MXene-NH2 and HATU powder prepared in step S1 to DMF solvent, sonicate until uniformly dispersed, then add the carbon oxide prepared in step S2 to completely impregnate and sonicate, react at 60-70℃ for 4-6 hours, wash with deionized water after the reaction, and vacuum dry to obtain carbon fiber grafted with titanium carbide MXene, i.e. the electromagnetic shielding layer.

4. The anti-interference absorbing copper foil for low-altitude aircraft according to claim 2, characterized in that, The solid-liquid ratio of the titanium carbide MXene to anhydrous ethanol is 1g:100-150ml.

5. The anti-interference absorbing copper foil for low-altitude aircraft according to claim 2, characterized in that, The concentration of the nitric acid is 65-70 wt%, and the liquid-solid ratio of the nitric acid to the pretreated carbon fiber is 10-20 mL: 1 g.

6. The anti-interference absorbing copper foil for low-altitude aircraft according to claim 1, characterized in that, The mass ratio of the oxidized carbon fiber to titanium carbide MXene-NH2 is 1:0.05-0.

2.

7. The method for preparing anti-interference absorbing copper foil for low-altitude aircraft according to any one of claims 1-6, characterized in that, Includes the following steps: (1) Pretreatment: Roughen the surface of the copper foil; (2) Lamination: Apply high-temperature resistant resin between the electromagnetic shielding layer and the copper foil layer, and then stack them in the order of copper foil layer-electromagnetic shielding layer-copper foil layer to obtain a laminated structure. (3) Hot pressing composite: The laminated structure is placed in a laminator and a temperature of 100-300℃ and a pressure of 1-10MPa are applied to make the layers tightly bonded and remove air bubbles, so as to obtain an anti-interference absorbing copper foil board.

8. The method for preparing anti-interference absorbing copper foil for low-altitude aircraft according to claim 7, characterized in that, The surface roughening treatment of the copper foil adopts the electrochemical roughening method, and the roughness Ra of the copper foil surface after roughening is 0.5-2.0μm; in step (3), the heat preservation and pressure preservation time of hot pressing composite is 30-60min.

9. The method for preparing anti-interference absorbing copper foil for low-altitude aircraft according to claim 7, characterized in that, The high-temperature resistant resin is one of bisphenol A cyanate, o-cresol epoxy resin, and epoxy resin F-51; the coating thickness of the high-temperature resistant resin is 50-300 μm.

10. The method for preparing anti-interference absorbing copper foil for low-altitude aircraft according to claim 7, characterized in that, The thickness of the copper foil layer is 10-50 μm, and the thickness of the electromagnetic shielding layer is 50-200 μm.

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