Aerogel with radio frequency dielectric near-zero performance and preparation method and application thereof

Abstract

The invention relates to the technical field of dielectric near-zero materials, in particular to aerogel with radio frequency dielectric near-zero performance and a preparation method and application thereof, and the aerogel comprises polyurethane / high-entropy alloy at carbon (PU / HEA at C) aerogel, polyurethane / copper at carbon (PU / Cu at C) and polyurethane / cobalt nickel copper alloy at carbon (PU / CoNiCu at C) aerogel. Wherein the polyurethane / copper at carbon aerogel and the polyurethane / cobalt-nickel-copper alloy at carbon aerogel show negative dielectric properties at 1M Hz to 110M Hz, the dielectric constant of the polyurethane / high-entropy alloy at carbon aerogel is changed from negative to positive, and the dielectric near-zero performance is achieved near 24M Hz.

Description

Technical Field

[0001] The present invention relates to the technical field of dielectric near-zero materials, and specifically relates to an aerogel with radio frequency dielectric near-zero performance, a preparation method thereof, and an application thereof. Background Art

[0002] Due to unique physical phenomena such as negative dielectric constant, negative magnetic permeability, dielectric near-zero or near-zero magnetic permeability, electromagnetic metamaterials exhibit novel physical properties such as negative refractive index and field enhancement effect, and have broad application prospects in electromagnetic shielding and absorption, optical nonlinearity, high-order harmonics, superlenses, etc. Dielectric near-zero materials, whose real part of the dielectric constant often experiences a change from positive to negative or from negative to positive, exhibit a very low dielectric constant near the plasma frequency, which has attracted extensive attention from researchers. Due to the extremely low dielectric constant, dielectric near-zero materials usually exhibit unique physical properties such as a refractive index close to zero and a huge electric field near the plasma frequency, thus showing important applications in fields such as perfect absorption and nonlinear nanodevices. Currently, there are mainly two methods to achieve dielectric near-zero materials. One is to continue the traditional metamaterial preparation process and achieve dielectric near-zero properties by constructing artificial periodic structures. The other is to construct a metal / dielectric medium stack (or plasma filler / dielectric medium composite) according to the effective medium theory, using the negative dielectric constant of metal or plasma fillers and the positive dielectric constant of the medium to achieve dielectric near-zero performance. For common plasma materials such as silver, gold, carbon nanotubes, graphene, and semiconductors, their plasma resonance frequencies are usually in the infrared, ultraviolet, visible light, etc. ranges. Therefore, there is very little research on radio frequency dielectric near-zero materials because it is difficult to objectively achieve plasma resonance in the radio frequency band.

[0003] However, the research and development of radio frequency dielectric near-zero materials are indeed of great significance and crucial. Because with the integration, intelligence, and miniaturization of electronic information technology, radio frequency devices have increasingly become the bottleneck in the development of electronic information technology, and there is an urgent need to innovate and break through the existing principles and technologies. In the terahertz band, dielectric near-zero materials are combined with devices (such as photodetectors and antennas) to achieve performance breakthroughs. Therefore, combining radio frequency dielectric near-zero materials with radio frequency devices is an effective means to achieve performance breakthroughs in radio frequency electronic devices.

[0004] Currently, the realization of radio frequency dielectric near-zero materials is mainly plasma filler / dielectric composites or ceramics. However, in order to be integrated with electronic devices, an important feature of radio frequency dielectric near-zero materials is light weight. But it is very difficult for these radio frequency dielectric near-zero materials to meet this characteristic. Therefore, it is necessary and urgent to design a lightweight radio frequency dielectric near-zero material. Summary of the Invention

[0005] The object of the present invention is to provide an aerogel with radio frequency dielectric near-zero performance, a preparation method thereof and an application.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] An aerogel with radio frequency dielectric near-zero performance, which is any one of polyurethane / high-entropy alloy@carbon aerogel, polyurethane / copper@carbon and polyurethane / cobalt-nickel-copper alloy@carbon aerogel.

[0008] Among them, the preparation method of the polyurethane / high-entropy alloy@carbon aerogel includes the following steps:

[0009] (1) Synthesis of high-entropy alloy@carbon aerogel

[0010] First, dissolve 1,3,5-tricarboxylic acid in a solution of ethanol and deionized water, stir, and label it as solution A;

[0011] Dissolve ferric chloride hexahydrate, nickel chloride hexahydrate, cobalt chloride hexahydrate, manganese chloride, copper chloride dihydrate and collagen peptide protein in deionized water, and label it as solution B;

[0012] Then add solution B to solution A and stir to form a high-entropy metal-organic gel / collagen peptide; pour it into a centrifuge tube and freeze-dry for 48 hours to obtain a dry high-entropy metal-organic gel / collagen peptide; anneal the dried high-entropy metal-organic gel / collagen peptide in a tubular furnace under argon protection at 1000 °C with a heating rate of 10 °C / min to obtain a high-entropy alloy@carbon aerogel;

[0013] (2) Preparation of polyurethane / high-entropy alloy@carbon aerogel

[0014] Dissolve polyurethane in deionized water and stir to obtain a polyurethane solution;

[0015] Then put the high-entropy alloy@carbon aerogel into a beaker, pour the polyurethane solution into the beaker, and vacuum soak it at room temperature until there are no bubbles; repeat the vacuum impregnation process until the polyurethane solution is completely immersed in the high-entropy alloy@carbon aerogel, then take it out and store it at 50 °C; after natural cooling to room temperature, obtain a polyurethane / high-entropy alloy@carbon aerogel.

[0016] Among them, the preparation method of the polyurethane / copper@carbon includes the following steps:

[0017] (1) Synthesis of copper@carbon aerogel

[0018] First, dissolve 1,3,5-tricarboxylic acid in a solution of ethanol and deionized water, stir, and label it as solution A;

[0019] Dissolve copper chloride dihydrate and collagen peptide protein in deionized water, and label it as solution B;

[0020] Then, solution B was added to solution A and stirred to form a metal-organic gel / collagen peptide; it was poured into a centrifuge tube and freeze-dried for 48 hours to obtain a dried metal-organic gel / collagen peptide; the dried metal-organic gel / collagen peptide was annealed in a tube furnace under argon protection at 1000 °C with a heating rate of 10 °C / min to obtain Cu@C aerogel;

[0021] (2) Preparation of polyurethane / Cu@C aerogel

[0022] Polyurethane was dissolved in deionized water and stirred to obtain a polyurethane solution;

[0023] Then, the Cu@C aerogel was placed in a beaker, and the polyurethane solution was poured into the beaker and vacuum-soaked at room temperature until there were no bubbles; the vacuum impregnation process was repeated until the polyurethane solution was completely immersed in the Cu@C aerogel, then it was taken out and stored at 50 °C, and after natural cooling to room temperature, polyurethane / Cu@C aerogel was obtained.

[0024] Among them, the preparation method of the polyurethane / cobalt-nickel-copper alloy@C aerogel includes the following steps:

[0025] (1) Synthesis of cobalt-nickel-copper alloy@C aerogel

[0026] First, 1,3,5-tricarboxylic acid was dissolved in a solution of ethanol and deionized water and vigorously stirred with ultrasonic waves, marked as solution A;

[0027] Nickel chloride hexahydrate, cobalt chloride hexahydrate, copper chloride dihydrate and collagen peptide protein were dissolved in deionized water, marked as solution B;

[0028] Then, solution B was added to solution A and stirred to form a metal-organic gel / collagen peptide; it was poured into a centrifuge tube and freeze-dried for 48 hours to obtain a dried metal-organic gel / collagen peptide; the dried metal-organic gel / collagen peptide was annealed in a tube furnace under argon protection at 1000 °C with a heating rate of 10 °C / min to obtain cobalt-nickel-copper alloy@C aerogel;

[0029] (2) Preparation of polyurethane / cobalt-nickel-copper alloy@C aerogel

[0030] Polyurethane was dissolved in deionized water and mechanically stirred at room temperature for 30 min to obtain a polyurethane solution;

[0031] Then, the cobalt-nickel-copper alloy@C aerogel was placed in a beaker, and the polyurethane solution was poured into the beaker and vacuum-soaked at room temperature until there were no bubbles; the vacuum impregnation process was repeated until the polyurethane solution was completely immersed in the cobalt-nickel-copper alloy@C aerogel, then it was taken out and stored at 50 °C, and after natural cooling to room temperature, polyurethane / cobalt-nickel-copper alloy@C aerogel was obtained.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] (1) The present invention designs for the first time a lightweight aerogel with radio frequency dielectric near-zero response, and prepares polyurethane / high-entropy alloy@carbon (PU / HEA@C) aerogel through an entropy engineering strategy.

[0034] (2) The present invention also prepares polyurethane / copper@carbon (PU / Cu@C) and polyurethane / cobalt-nickel-copper alloy@carbon (PU / CoNiCu@C) aerogels. Among them, the polyurethane / copper@carbon aerogel and the polyurethane / cobalt-nickel-copper alloy@carbon aerogel exhibit negative dielectric properties in the range of 1 MHz to 110 MHz, while the dielectric constant of the polyurethane / high-entropy alloy@carbon aerogel changes from negative to positive, and realizes dielectric near-zero performance near 24 MHz. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is the SEM image of the high-entropy alloy@carbon aerogel.

[0036] Figure 2 It is the TEM image and the mapping distribution image of metal elements of the high-entropy alloy@carbon aerogel.

[0037] Figure 3 In, (a) is the XRD image of the high-entropy alloy@carbon aerogel; (b) is the proportion of metal elements of the high-entropy alloy@carbon aerogel.

[0038] Figure 4 It is the SEM image of the polyurethane / high-entropy alloy@carbon aerogel.

[0039] Figure 5 It is the relationship diagram between the real part of the dielectric constant and the frequency of the polyurethane / high-entropy alloy@carbon aerogel.

[0040] Figure 6 In, (a) is the SEM image of the copper@carbon aerogel; (b) is the XRD image of the copper@carbon aerogel.

[0041] Figure 7 It is the SEM image of the polyurethane / copper@carbon aerogel.

[0042] Figure 8 It is the relationship diagram between the real part of the dielectric constant and the frequency of the polyurethane / copper@carbon aerogel.

[0043] Figure 9 In, (a) is the SEM image of the cobalt-nickel-copper@carbon aerogel; (b) is the XRD image of the cobalt-nickel-copper@carbon aerogel.

[0044] Figure 10 It is the SEM image of the polyurethane / cobalt-nickel-copper alloy@carbon aerogel.

[0045] Figure 11 It is a graph of the relationship between the real part of the dielectric constant and the frequency of polyurethane / cobalt-nickel-copper alloy@carbon aerogel. Specific embodiments

[0046] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0047] Example 1

[0048] A preparation method of polyurethane / high-entropy alloy@carbon (PU / HEA@C) aerogel, the specific steps are as follows:

[0049] (1) Synthesis of high-entropy alloy@carbon (HEA@C) aerogel

[0050] First, dissolve 1,3,5-tricarboxylic acid (1 g) in a solution of ethanol (10 mL) and deionized water (3 mL), and stir vigorously with ultrasonic waves, marked as solution A.

[0051] Dissolve ferric chloride hexahydrate (1 mmol), nickel chloride hexahydrate (1 mmol), cobalt chloride hexahydrate (1 mmol), manganese chloride (1 mmol), copper chloride dihydrate (1 mmol) and collagen peptide protein (1 g) in deionized water (30 mL), marked as solution B.

[0052] Then add solution B to solution A and stir. After a few minutes, a high-entropy metal-organic gel / collagen peptide (HE-MOG / CP) is formed. Pour the gel into a centrifuge tube and freeze-dry for 48 hours to obtain dry HE-MOG / CP. Anneal the dried HE-MOG / CP in a tube furnace at 1000 °C under argon protection at a heating rate of 10 °C / min for 2 hours to obtain high-entropy alloy@carbon (HEA@C) aerogel.

[0053] Use a field emission scanning electron microscope (Philips XL-30) to characterize the microstructure of the material. Figure 1 a, Figure 1 b is the SEM image of the high-entropy alloy@carbon aerogel. It can be observed that many high-entropy alloy particles are loaded on the carbon sheet layer structure of the aerogel, and a porous structure is observed.

[0054] Use a high-resolution transmission electron scanning microscope (FEI Talos F200x) to characterize the morphology and element distribution of the high-entropy alloy@carbon aerogel, as Figure 2As shown, it can be observed that the high-entropy alloy particles are in the nanometer scale, and the five metal elements of manganese, iron, cobalt, nickel, and copper are evenly distributed.

[0055] Figure 3 a is the XRD pattern of the high-entropy alloy@carbon aerogel. Diffraction peaks of crystal planes (111), (200), (220), and (311) are observed. Compared with the PDF card, it is in good agreement, proving that a single-phase high-entropy alloy with a face-centered cubic structure is formed. The proportion of metal elements in the high-entropy alloy@carbon aerogel is tested using an inductively coupled plasma atomic emission spectrometer (PE optima 6000), and the results are as Figure 3 shown in b. The atomic ratio of manganese element is 5.1%, that of iron element is 25.3%, that of cobalt element is 19.4%, that of nickel element is 27.4%, and that of copper element is 22.8%. The definition of high-entropy alloy is that in a multi-element alloy of a single phase, the proportion of each element is between 5% and 35%. The above test results meet this condition, proving that high-entropy alloy nanoparticles are successfully synthesized in the carbon aerogel.

[0056] (2) Preparation of polyurethane / high-entropy alloy@carbon (PU / HEA@C) aerogel

[0057] Dissolve polyurethane (20 ml) in deionized water (30 ml), and mechanically stir for 30 min at room temperature to obtain a polyurethane solution. Then put the HEA@C aerogel into a beaker, pour the polyurethane solution into the beaker, and soak it in a vacuum at room temperature until there are no bubbles. Repeat the vacuum impregnation process until the polyurethane solution is completely immersed in the HEA@C aerogel, then take it out and store it at 50 °C for 4 hours. After naturally cooling to room temperature, polyurethane / high-entropy alloy@carbon (PU / HEA@C) aerogel is obtained. It can be seen that even on a single leaf, a large piece of aerogel can be carried, proving the light weight of the polyurethane / high-entropy alloy@carbon aerogel.

[0058] Figure 4 This is the SEM image of the polyurethane / high-entropy alloy@carbon aerogel. A large number of porous structures can be observed, and from the polyurethane-carbon interface, it can be seen that polyurethane is mainly attached to the surface of the carbon aerogel without breaking the porous carbon network structure of the carbon aerogel.

[0059] Figure 5 This is the relationship diagram between the real part of the dielectric constant and the frequency of the polyurethane / high-entropy alloy@carbon aerogel. The real part of the dielectric constant realizes a transition from negative to positive, and the dielectric constant approaches zero near 24 MHz, thus realizing the radio frequency dielectric near-zero performance.

[0060] Example 2

[0061] A preparation method of a polyurethane / copper@carbon (PU / Cu@C) aerogel, and the specific steps are as follows:

[0062] (1) Synthesis of copper@carbon (Cu@C) aerogel

[0063] First, dissolve 1,3,5-tricarboxylic acid (1 g) in a solution of ethanol (10 mL) and deionized water (3 mL), and stir vigorously with ultrasonic waves, marked as solution A.

[0064] Dissolve copper dichloride dihydrate (5 mmol) and collagen peptide protein (1 g) in deionized water (30 mL), marked as solution B.

[0065] Then add solution B to solution A and stir. After a few minutes, a metal-organic gel / collagen peptide (MOG / CP) is formed. Pour the gel into a centrifuge tube and freeze-dry for 48 hours to obtain dry MOG / CP. Anneal the dried MOG / CP in a tube furnace under argon protection at 1000 °C with a heating rate of 10 °C / min for 2 hours to obtain copper@carbon (Cu@C) aerogel.

[0066] Use a field emission scanning electron microscope (Philips XL-30) to characterize the microtopography of the material. Figure 6 a is the SEM image of the copper@carbon aerogel. It can be observed that many copper metal particles are loaded on the carbon sheet layer structure of the aerogel, and a porous structure is observed. Use an X-ray diffractometer (D / MaxB, Rigaku) to characterize the phase structure of the material. Figure 6 b is the XRD pattern of the copper@carbon aerogel. Diffraction peaks of crystal planes (111), (200), (220), and (311) are observed, which are in good agreement with the PDF card, proving that elemental copper with a face-centered cubic structure is generated, and no metal copper oxide is generated.

[0067] (2) Preparation of polyurethane / copper@carbon (PU / Cu@C) aerogel

[0068] Dissolve polyurethane (20 mL) in deionized water (30 mL), and mechanically stir at room temperature for 30 min to obtain a polyurethane solution. Then put the Cu@C aerogel into a beaker, pour the polyurethane solution into the beaker, and soak it in a vacuum at room temperature until there are no bubbles. Repeat the vacuum impregnation process until the polyurethane solution is completely immersed in the Cu@C aerogel, then take it out and store it at 50 °C for 4 hours. After naturally cooling to room temperature, a polyurethane / copper@carbon (PU / Cu@C) aerogel is obtained.

[0069] Figure 7SEM image of polyurethane / copper@carbon aerogel shows a large number of porous structures. It can be seen from the polyurethane-carbon interface that polyurethane mainly adheres to the surface of carbon aerogel without damaging the porous carbon network structure of carbon aerogel.

[0070] Figure 8 Relationship diagram between the real part of dielectric constant and frequency of polyurethane / copper@carbon aerogel. The real part of dielectric constant of the material was tested from 1 MHz to 110 MHz using an impedance analyzer (Agilent 4294A). Polyurethane / copper@carbon aerogel shows negative dielectric constant within the tested frequency range, achieving negative dielectric properties.

[0071] Example 3

[0072] A preparation method of polyurethane / cobalt-nickel-copper alloy@carbon (PU / CoNiCu@C) aerogel, the specific steps are as follows:

[0073] (1) Synthesis of cobalt-nickel-copper alloy@carbon (CoNiCu@C) aerogel

[0074] First, dissolve 1,3,5-tricarboxylic acid (1 g) in a solution of ethanol (10 mL) and deionized water (3 mL), and stir vigorously with ultrasonic waves, marked as solution A.

[0075] Nickel chloride hexahydrate (1.67 mmol), cobalt chloride hexahydrate (1.67 mmol), copper chloride dihydrate (1.67 mmol) and collagen peptide protein (1 g) are dissolved in deionized water (30 mL), marked as solution B.

[0076] Then add solution B to solution A and stir. After a few minutes, a metal-organic gel / collagen peptide (MOG / CP) is formed. Pour the gel into a centrifuge tube and freeze-dry for 48 hours to obtain dry MOG / CP. Anneal the dried MOG / CP in a tube furnace at 1000 °C under argon protection at a heating rate of 10 °C / min for 2 hours to obtain cobalt-nickel-copper alloy@carbon (CoNiCu@C) aerogel.

[0077] Use a field emission scanning electron microscope (Philips XL-30) to characterize the microstructure of the material. Figure 9 a is the SEM image of cobalt-nickel-copper@carbon aerogel, and it can be observed that alloy particles are loaded on the carbon sheet layer structure of the aerogel. Use an X-ray diffractometer (D / MaxB, Rigaku) to characterize the phase structure of the material. Figure 9 b is the XRD pattern of cobalt-nickel-copper@carbon aerogel. Diffraction peaks of crystal planes (111), (200), (220) and (311) are observed, which are in good agreement with the PDF card, proving that an alloy with a face-centered cubic structure is formed.

[0078] (2) Preparation of Polyurethane / Cobalt-Nickel-Copper Alloy@Carbon (PU / CoNiCu@C) Aerogel

[0079] Dissolve polyurethane (20 mL) in deionized water (30 mL), and mechanically stir for 30 min at room temperature to obtain a polyurethane solution. Then, place the CoNiCu@C aerogel in a beaker, pour the polyurethane solution into the beaker, and soak it under vacuum at room temperature until no bubbles are present. Repeat the vacuum impregnation process until the polyurethane solution is completely immersed in the CoNiCu@C aerogel. Then, take it out and store it at 50 °C for 4 hours. After naturally cooling to room temperature, the polyurethane / cobalt-nickel-copper alloy@carbon (PU / CoNiCu@C) aerogel is obtained.

[0080] Figure 10 It is the SEM image of the polyurethane / cobalt-nickel-copper alloy@carbon aerogel. A large number of porous structures can be observed. And from the polyurethane-carbon interface, it can be seen that the polyurethane is mainly attached to the surface of the carbon aerogel without damaging the porous carbon network structure of the carbon aerogel.

[0081] Figure 11 It is the graph of the relationship between the real part of the dielectric constant and the frequency of the polyurethane / cobalt-nickel-copper alloy@carbon aerogel. The real part of the dielectric constant is negative within the tested frequency range, realizing negative dielectric properties.

[0082] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An aerogel having near-zero radio frequency dielectric performance, characterized in that: It is any one of polyurethane / high entropy alloy@carbon aerogel, polyurethane / copper@carbon and polyurethane / cobalt-nickel-copper alloy@carbon aerogel.

2. The method for preparing the aerogel having near-zero radio frequency dielectric performance according to claim 1, characterized in that: The preparation method of the polyurethane / high entropy alloy@carbon aerogel comprises the following steps: (1) Synthesis of high entropy alloy@carbon aerogel First, 1,3,5-tricarboxylic acid was dissolved in a solution of ethanol and deionized water and stirred, which was labeled as solution A; Ferric chloride hexahydrate, nickel chloride hexahydrate, cobalt chloride hexahydrate, manganese chloride, copper chloride dihydrate and collagen peptide protein were dissolved in deionized water, which was labeled as solution B; Then, solution B was added to solution A and stirred to form high entropy metal organogel / collagen peptide; the high entropy metal organogel / collagen peptide was poured into a centrifuge tube and freeze-dried for 48 hours to obtain dry high entropy metal organogel / collagen peptide; the dried high entropy metal organogel / collagen peptide was annealed in a tubular furnace at 1000°C under argon protection at a heating rate of 10°C / min to obtain high entropy alloy@carbon aerogel; (2) Preparation of polyurethane / high entropy alloy@carbon aerogel.

3. The method for preparing aerogel having radio frequency dielectric near-zero performance according to claim 2, characterized in that: The step (2) in the preparation method of the polyurethane / high entropy alloy@carbon aerogel is specifically as follows: dissolving the polyurethane in deionized water and stirring to obtain a polyurethane solution; Then the high entropy alloy @ carbon aerogel was placed in a beaker, the polyurethane solution was poured into the beaker, and vacuum soaked at room temperature until there were no bubbles; the vacuum impregnation process was repeated until the polyurethane solution was completely immersed in the high entropy alloy @ carbon aerogel, and then taken out and stored at 50°C; after naturally cooling to room temperature, the polyurethane / high entropy alloy @ carbon aerogel was obtained.

4. The method for preparing aerogel having radio frequency dielectric near-zero performance according to claim 1, characterized in that: The preparation method of the polyurethane / copper@carbon comprises the following steps: (1) Synthesis of copper@carbon aerogel First, 1,3,5-tricarboxylic acid was dissolved in a solution of ethanol and deionized water and stirred, which was marked as solution A; Copper chloride dihydrate and collagen peptide protein were dissolved in deionized water, labeled as solution B; Then, solution B was added to solution A and stirred to form metal organic gel / collagen peptide; the metal organic gel / collagen peptide was poured into a centrifuge tube and freeze-dried for 48 hours to obtain a dry metal organic gel / collagen peptide; the dried metal organic gel / collagen peptide was annealed in a tubular furnace at 1000°C under argon protection at a heating rate of 10°C / min to obtain copper@carbon aerogel; (2) Preparation of polyurethane / copper@carbon aerogel.

5. The method for preparing aerogel with near-zero radio frequency dielectric performance according to claim 4, characterized in that: The step (2) in the preparation method of the polyurethane / copper@carbon aerogel is specifically as follows: dissolving polyurethane in deionized water and stirring to obtain a polyurethane solution; Then the copper@carbon aerogel was placed in a beaker, the polyurethane solution was poured into the beaker, and vacuum soaked at room temperature until there were no bubbles; the vacuum impregnation process was repeated until the polyurethane solution was completely immersed in the copper@carbon aerogel, and then taken out and stored at 50°C. After naturally cooling to room temperature, the polyurethane / copper@carbon aerogel was obtained.

6. The method for preparing aerogel with near-zero radio frequency dielectric performance according to claim 1, characterized in that: The preparation method of the polyurethane / cobalt-nickel-copper alloy@carbon aerogel comprises the following steps: (1) Synthesis of Cobalt-Nickel-Copper Alloy@Carbon Aerogel First, 1,3,5-tricarboxylic acid was dissolved in a solution of ethanol and deionized water and stirred vigorously with ultrasound, which was labeled as solution A; Nickel chloride hexahydrate, cobalt chloride hexahydrate, copper chloride dihydrate and collagen peptide protein were dissolved in deionized water, marked as solution B; Then, solution B was added to solution A and stirred to form metal organic gel / collagen peptide; the metal organic gel / collagen peptide was poured into a centrifuge tube and freeze-dried for 48 hours to obtain a dry metal organic gel / collagen peptide; the dried metal organic gel / collagen peptide was annealed in a tubular furnace at 1000°C under argon protection at a heating rate of 10°C / min to obtain cobalt nickel copper alloy@carbon aerogel; (2) Preparation of polyurethane / cobalt-nickel-copper alloy@carbon aerogel.

7. The method for preparing aerogel with radio frequency dielectric near-zero performance according to claim 6, characterized in that: The step (2) in the preparation method of the polyurethane / cobalt-nickel-copper alloy@carbon aerogel is specifically as follows: dissolving the polyurethane in deionized water, and mechanically stirring at room temperature for 30 minutes to obtain a polyurethane solution; Then the cobalt-nickel-copper alloy@carbon aerogel was placed in a beaker, the polyurethane solution was poured into the beaker, and vacuum soaked at room temperature until there were no bubbles; the vacuum impregnation process was repeated until the polyurethane solution was completely immersed in the cobalt-nickel-copper alloy@carbon aerogel, and then taken out and stored at 50°C. After naturally cooling to room temperature, the polyurethane / cobalt-nickel-copper alloy@carbon aerogel was obtained.

8. Use of the aerogel with near-zero radio frequency dielectric performance as claimed in claim 1 in radio frequency electronic devices.

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