Broadband electromagnetic wave invisibility metamaterial and preparation method and application thereof

Abstract

The application discloses a broadband electromagnetic wave stealth metamaterial and a preparation method and application thereof, and belongs to the technical field of electromagnetic stealth materials. The broadband electromagnetic wave stealth metamaterial utilizes an intermediate body to adjust the molecular chain spacing of a polypyrrole, and forms a two-dimensional spatial arrangement of polypyrrole molecular chains. The preparation method comprises the following steps: simultaneously spraying a mixed solution A of a first intermediate body and pyrrole and a mixed solution B of a second intermediate body and an oxidizing agent on the surface of a substrate to perform a polymerization reaction; and after the reaction is completed, washing is performed, so that the broadband electromagnetic wave stealth metamaterial is obtained. The application further discloses the application of the material in the fields of electromagnetic shielding, electromagnetic stealth, sensors or intelligent touch transmission. The electromagnetic wave material prepared by the application has a molecular level molecular resonance ring structure, simultaneously has more regular and longer single molecular chains and molecular chain arrangement, and can realize the stealth function of a wider electromagnetic wave.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic stealth materials technology, and particularly relates to a broadband electromagnetic wave stealth metamaterial, its preparation method and application. Background Technology

[0002] In recent years, problems such as electromagnetic interference, information leakage, and electromagnetic pollution caused by electromagnetic waves have been increasing, seriously affecting the normal operation of electronic equipment and posing a serious threat to the life and health of humans and animals. Therefore, the stealth and shielding of electromagnetic radiation has always been an important research topic in both scientific and military fields.

[0003] With the rapid development of military detection and modern communication technologies, humanity is no longer limited to the electromagnetic wave frequencies covered by simple electronic devices and radar. The stealth and shielding effects of electromagnetic waves are increasingly covering multiple frequency bands, including infrared, visible light, and ultraviolet light. Currently, most electromagnetic shielding materials suffer from limitations in structure, function, and shielding band, severely restricting their application. Achieving good compatibility across a wide frequency band presents new challenges to the properties of the materials themselves and their further control.

[0004] Therefore, how to provide a broadband electromagnetic shielding material through reasonable structural design is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a broadband electromagnetic wave stealth metamaterial, its preparation method, and its application, which can solve the technical problem that existing electromagnetic stealth or shielding materials are only effective against electromagnetic waves of a single frequency band in terms of structure and function.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A broadband electromagnetic wave stealth metamaterial includes an intermediate and an intrinsically conductive polymer polypyrrole (PPy). The intermediate is used to adjust the spacing between polypyrrole molecular chains to form polypyrrole molecular chains arranged in a two-dimensional space.

[0008] Beneficial Effects: The two-dimensional spatial arrangement of polypyrrole molecular chains can better cope with the corresponding frequency band characteristics and polarization state changes of working electromagnetic waves. Traditional metamaterials are designed by combining microstructures of metal resonant rings, while this invention uses polypyrrole molecules as resonant rings, designing from within the molecular structure. By adjusting the spacing of polypyrrole molecular chains using intermediates, two-dimensional spatially arranged polypyrrole molecular chains are formed, and the molecular structure is rearranged so that each molecular structure becomes a resonant ring. These resonant rings are arranged in a specific way to constitute the metamaterial. To achieve the double negative properties of metamaterials, molecular polymerization must be directional. Random polymerization, although conductive and possessing a certain shielding effect, cannot form metamaterials. This invention, through specific experimental methods, adjusts the spacing of polypyrrole molecular chains to ensure that the material forms a two-dimensional planar and linear structure, which is the key to achieving wide-band double negative properties and obtaining metamaterial performance.

[0009] Preferably, the interchain spacing of polypyrrole molecules is 0.25-0.45 nm.

[0010] Beneficial Effects: Metal resonant rings are fundamental to metamaterial research. Metamaterials must simultaneously possess negative dielectric constant and magnetic permeability to achieve stealth effects. Polypyrrole itself is a conductive polymer with inherent electromagnetic shielding properties, but it does not exhibit metamaterial properties without specific initiation. This invention, by adjusting the interchain spacing of polypyrrole molecules to 0.25-0.45 nm, ensures a more regular two-dimensional spatial arrangement, and within 1×10⁻⁶... 8 -2×10 8 It possesses both negative dielectric constant and magnetic permeability at the Hz level, which is more conducive to achieving wideband operating scenarios.

[0011] Preferably, the intermediate includes a first intermediate and a second intermediate;

[0012] Preferably, the first intermediate includes one or more of a disulfonic acid compound and a dicarboxylic acid compound that can react with the NH2 group in the pyrrole monomer;

[0013] More preferably, it is one or any combination of 4,4'-biphenyl disulfonic acid (BPDSA), 1,2-ethanedisulfonic acid, 1,4-butanedisulfonic acid, 4,4'-biphenyl dicarboxylic acid and 1,4-butanedicarboxylic acid;

[0014] The second intermediate is a metal-organic ligand, including one or any combination of sodium ions, zinc ions, iron ions, copper ions and silver ions.

[0015] More preferably, it is tetrasodium 1,3,6,8-pyrene tetrasulfonate (PTSA) and / or sodium phthalocyanine copper tetrasulfonate.

[0016] Beneficial effects: Tetrasodium 1,3,6,8-pyrenetetrasulfonate (PTSA) and / or sodium phthalocyanine copper tetrasulfonate are more conducive to enhancing interchain charge transport between conductive polymer chains, and the spatial and electrostatic interactions between these two intermediates and polypyrrole are beneficial to the self-assembly of polypyrrole chains.

[0017] A method for preparing a broadband electromagnetic wave stealth metamaterial includes the following steps:

[0018] A mixed solution A of the first intermediate and pyrrole and a mixed solution B of the second intermediate and oxidant were simultaneously sprayed onto the substrate surface for polymerization. After the reaction was completed, the substrate was cleaned to obtain the broadband electromagnetic wave stealth metamaterial.

[0019] Preferably, it includes the following steps:

[0020] (1) Preparation of mixed solution A: Dissolve the first intermediate in an organic solvent to obtain a first intermediate solution, then mix the pyrrole (Py) solution with the first intermediate solution and stir at -5-40℃ for 0.5-5h, preferably at 0-20℃ for 1-3h, to obtain mixed solution A;

[0021] (2) Preparation of mixed solution B: The second intermediate is added to the oxidant solution and stirred at room temperature for 0.5-2 hours until dissolved, preferably for 0.8-1.5 hours, to obtain mixed solution B;

[0022] (3) Matrix pretreatment: Place the matrix in an environment with a preset reaction temperature until the matrix temperature is the same as the preset reaction temperature;

[0023] (4) Preparation of broadband electromagnetic wave stealth metamaterial: Mixed solution A and mixed solution B are sprayed onto the substrate surface at a certain ratio using two spray gun injection pumps to carry out polymerization reaction. After the reaction, the substrate is repeatedly washed with distilled water and anhydrous ethanol to remove impurities, dried, and then peeled off from the substrate as needed to obtain the broadband electromagnetic wave stealth metamaterial.

[0024] Wave-stealth metamaterials.

[0025] Preferably, the substrate is a flexible substrate or a rigid substrate, including but not limited to fabrics, films, glass, walls, and instrument surfaces; the substrate shape can be any shape, including but not limited to planar, spherical, triangular, or irregular shapes; the substrate material includes but is not limited to organic materials, inorganic materials, and natural materials.

[0026] Beneficial effects: The method provided by this invention has no limitations on the substrate, thus broadening the application field.

[0027] Preferably, the concentration of the pyrrole solution in step (1) is 0.5-20 wt%, more preferably 1-10 wt%, the concentration of the first intermediate solution is 0.01-1 wt%, more preferably 0.05-0.5 wt%, and the volume ratio of the pyrrole solution to the first intermediate solution is (100-350):1.

[0028] Preferably, the concentration of the oxidant solution in step (2) is 0.1-1 mol / L, more preferably 0.3-0.8 mol / L, and the concentration of the second intermediate is 0.1-1.5 wt%.

[0029] The mass ratio of the second intermediate to the first intermediate is 1:3 to 1:50, more preferably 1:5 to 1:20.

[0030] Beneficial effect: This mass ratio is more conducive to obtaining well-arranged two-dimensional network polypyrrole molecular chains.

[0031] Preferably, the oxidant is one or more of ferric oxide, ammonium persulfate, copper chloride, or hydrogen peroxide. The solvent is one or more of acetone, methanol, ethylene glycol, and dimethyl sulfoxide, with acetone being preferred.

[0032] Beneficial effects: When using acetone solution as the oxidant, the morphology and structure of polypyrrole molecular chains can be better controlled.

[0033] Preferably, during the spraying process, the spraying speed ratio (i.e., the propulsion speed in step (4)) of mixed solution A to mixed solution B is 2:1 to 10:1, more preferably 3:1 to 6:1.

[0034] Beneficial effects: By limiting the spraying speed, the rate of pyrrole polymerization can be controlled, making the polymerization process more stable. This allows the molecular chains to grow more stably according to the design, resulting in a more regular arrangement of polypyrrole molecular chains.

[0035] Preferably, the polymerization reaction is carried out at a temperature of -5 to 40°C for 0.5 to 9 hours.

[0036] More preferably, the polymerization reaction is carried out at a temperature of 0-20°C for 2-3 hours.

[0037] Beneficial effects: Lower polymerization temperatures allow for more stable polymerization reactions and result in better morphologies. Appropriate polymerization time can prevent oxidants from over-oxidizing the polypyrrole molecular chains.

[0038] Applications of a broadband electromagnetic wave stealth metamaterial in the fields of electromagnetic shielding, electromagnetic stealth, sensors, or smart touch conduction.

[0039] Beneficial effects: Unlike shielding materials, the metamaterial in this invention has a stealth function. Shielding is a lower-level function; stealth is like an invisibility cloak, making the object completely invisible. Shielding, on the other hand, is like an iron box encasing an object; while it prevents external access to the interior, the box itself is visible. Shielding materials only need to be conductive; double negative properties are not required.

[0040] Therefore, existing shielding materials cannot be directly used as stealth metamaterials. However, the metamaterial in this invention can achieve 1×10⁻⁶ Ω·cm. 8 -2×10 8 It possesses the characteristic that both its dielectric constant and permeability are negative (i.e., double negative) between Hz, thereby achieving stealth capabilities.

[0041] Compared with the prior art, the present invention has the following advantages and technical effects:

[0042] This invention designs a conjugated system of polypyrrole single molecular chains and adjusts the inter-chain spacing to prepare a broadband electromagnetic wave stealth metamaterial with wide-bandwidth, lightweight, and flexible characteristics. The prepared electromagnetic wave material has a molecular-level molecular resonant ring structure, and also has more regular and longer single molecular chains and molecular chain arrangements, enabling it to achieve stealth functionality over a wider electromagnetic wave range. Attached Figure Description

[0043] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0044] Figure 1 This is a schematic diagram of the molecular structure of the broadband electromagnetic wave stealth metamaterial obtained in this invention;

[0045] Figure 2 Here is a SEM image of the broadband electromagnetic wave stealth metamaterial obtained in Example 1;

[0046] Figure 3 The graph shows the dielectric constant of the broadband electromagnetic wave stealth metamaterial obtained in Example 2.

[0047] Figure 4 The graph shows the electromagnetic conductivity of the broadband electromagnetic wave stealth metamaterial obtained in Example 2.

[0048] Figure 5 The infrared spectrum of the broadband electromagnetic wave stealth metamaterial obtained in Example 3;

[0049] Figure 6 The image shows the XRD pattern of the broadband electromagnetic wave stealth metamaterial obtained in Example 3.

[0050] Figure 7This is a schematic diagram of the ultraviolet light transmittance detection device in this invention;

[0051] Figure 8 This is a graph showing the UV transmittance results obtained in Example 4;

[0052] Figure 9 This is a schematic diagram of the infrared light transmittance detection device in this invention.

[0053] Figure 10 This is a graph showing the infrared temperature detection results of the internal environment of the broadband electromagnetic stealth metamaterial obtained in Example 4. Detailed Implementation

[0054] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0056] This invention provides a broadband electromagnetic wave stealth metamaterial with the following molecular structure: Figure 1 As shown, it includes an intermediate and an intrinsically conductive polymer, polypyrrole (PPy). The intermediate is used to adjust the spacing between the polypyrrole molecular chains to form polypyrrole molecular chains arranged in a two-dimensional space.

[0057] In a preferred embodiment, the interchain spacing of polypyrrole molecules is 0.25-0.45 nm.

[0058] In a preferred embodiment, the intermediate includes a first intermediate and a second intermediate;

[0059] In a preferred embodiment, the first intermediate includes one or more of a disulfonic acid compound and a dicarboxylic acid compound that can react with the NH2 group in the pyrrole monomer.

[0060] More preferably, it is one or any combination of 4,4'-biphenyl disulfonic acid (BPDSA), 1,2-ethanedisulfonic acid, 1,4-butanedisulfonic acid, 4,4'-biphenyl dicarboxylic acid, and 1,4-butanedicarboxylic acid.

[0061] The second intermediate is a metal-organic ligand, including one or any combination of sodium ions, zinc ions, iron ions, copper ions and silver ions.

[0062] More preferably, it is tetrasodium 1,3,6,8-pyrene tetrasulfonate (PTSA) and / or sodium phthalocyanine copper tetrasulfonate.

[0063] This invention also provides a method for preparing a broadband electromagnetic wave stealth metamaterial, comprising the following steps:

[0064] A mixed solution A of the first intermediate and pyrrole and a mixed solution B of the second intermediate and oxidant were simultaneously sprayed onto the substrate surface for polymerization. After the reaction was completed, the substrate was cleaned to obtain the broadband electromagnetic wave stealth metamaterial.

[0065] In a preferred embodiment, the specific steps include:

[0066] (1) Preparation of mixed solution A: Dissolve the first intermediate in an organic solution to obtain a first intermediate solution, then mix the pyrrole (Py) solution with the first intermediate solution and stir at -5-40℃ for 0.5-5h, preferably at 0-20℃ for 1-3h, to obtain mixed solution A;

[0067] (2) Preparation of mixed solution B: The second intermediate is added to the oxidant solution and stirred at room temperature for 0.5-2 hours until dissolved, preferably for 0.8-1.5 hours, to obtain mixed solution B;

[0068] (3) Matrix pretreatment: Place the matrix in an environment with a preset reaction temperature until the matrix temperature is the same as the preset reaction temperature;

[0069] (4) Preparation of broadband electromagnetic wave stealth metamaterial: Mixed solution A and mixed solution B are sprayed onto the substrate surface at a certain ratio of injection speed through two spray guns to carry out polymerization reaction. After the reaction is completed, the substrate is repeatedly washed with distilled water and anhydrous ethanol to remove impurities and then dried to obtain the broadband electromagnetic wave stealth metamaterial.

[0070] In a preferred embodiment, the substrate is a flexible substrate or a rigid substrate, including but not limited to fabrics, films, glass, walls, and instrument surfaces; the substrate shape can be any shape, including but not limited to planar, spherical, triangular, or irregular shapes; the substrate material includes but is not limited to organic materials, inorganic materials, and natural materials.

[0071] In a preferred embodiment, the concentration of the pyrrole solution in step (1) is 0.5-20 wt%, more preferably 1-10 wt%, the concentration of the first intermediate solution is 0.01-1 wt%, more preferably 0.05-0.5 wt%, and the volume ratio of the pyrrole solution to the first intermediate solution is (100-350):1.

[0072] In a preferred embodiment, the concentration of the oxidant solution in step (2) is 0.1-1 mol / L, more preferably 0.3-0.8 mol / L, and the concentration of the second intermediate is 0.1-1.5 wt%.

[0073] The mass ratio of the second intermediate to the first intermediate is 1:3 to 1:50, more preferably 1:5 to 1:20.

[0074] In a preferred embodiment, the oxidant is one or any combination of ferric oxide, ammonium persulfate, copper chloride, or hydrogen peroxide. The solvent is one or any combination of acetone, methanol, ethylene glycol, and dimethyl sulfoxide, preferably acetone.

[0075] In a preferred embodiment, during the spraying process, the spraying speed ratio (i.e., the propulsion speed in step (4)) of mixed solution A to mixed solution B is 2:1 to 10:1, more preferably 3:1 to 6:1.

[0076] In a preferred embodiment, the polymerization reaction is carried out at a temperature of -5 to 40°C for a duration of 0.5 to 9 hours.

[0077] In a more preferred embodiment, the polymerization reaction is carried out at a temperature of 0-20°C for 2-3 hours.

[0078] This invention also provides an application of a broadband electromagnetic wave stealth metamaterial in the fields of electromagnetic shielding, electromagnetic stealth, sensors, or smart touch conduction.

[0079] Unless otherwise specified, all raw materials used in this invention are obtained through commercial channels.

[0080] Among them, pure polypyrrole was purchased from commercial sources, and the molecular chain spacing was 0.68 nm.

[0081] In the embodiments of this invention, room temperature or ambient temperature refers to 25±3℃.

[0082] Example 1

[0083] A method for preparing a broadband electromagnetic wave stealth metamaterial includes the following steps:

[0084] (1) Prepare a 1 ml solution of 1,2-ethanedisulfonic acid acetone with a concentration of 0.01 wt% and a 100 ml solution of Py(pyrrole) acetone with a concentration of 0.5 wt%. Mix the two solutions and stir at 5 °C for 1 h to obtain mixed solution A.

[0085] (2) Prepare a 100ml FeCl3 acetone solution, then add PTSA and stir at room temperature for 1h to obtain mixed solution B; wherein the concentration of FeCl3 is 0.3mol / L, and the mass ratio of 1,2-ethanedisulfonic acid to PTSA in step (1) is 5:1.

[0086] (3) Place the substrate fabric in an environment of 10°C until the surface reaches 10°C. Then add mixed solution A and mixed solution B to two spray gun injection pumps respectively. Set the speed ratio of the injection pump of mixed solution A to the injection pump of mixed solution B to 3:1 and spray it onto the substrate surface. After all the solution is used up, place it in an environment of 10°C for 1 hour to polymerize. After the reaction is complete, wash it repeatedly with distilled water and anhydrous ethanol to remove impurities. After drying or air drying, broadband electromagnetic wave stealth metamaterial is obtained, in which the polypyrrole molecular chain spacing is ~0.39nm.

[0087] Example 2

[0088] A method for preparing a broadband electromagnetic wave stealth metamaterial includes the following steps:

[0089] (1) Prepare a 0.25 ml BPDSA methanol solution with a concentration of 0.05 wt% and a 50 ml Py (pyrrole) methanol solution with a concentration of 1 wt%. Mix the two solutions and stir at 0℃ for 0.5 h to obtain mixed solution A.

[0090] (2) Prepare a 50 ml ammonium persulfate methanol solution, then add sodium phthalocyanine copper tetrasulfonate and stir at room temperature for 0.5 h to obtain mixed solution B; wherein the concentration of ammonium persulfate is 0.1 mol / L, and the mass ratio of BPDSA to sodium phthalocyanine copper tetrasulfonate in step (1) is 50:1.

[0091] (3) Place the substrate glass plate in a 0℃ environment until the surface temperature reaches 0℃. Then add mixed solution A and mixed solution B to two spray gun injection pumps respectively. Set the speed ratio of the injection pump of mixed solution A to the injection pump of mixed solution B to 2:1 and spray it onto the substrate surface. After all the solutions are used up, place it in a 0℃ environment for polymerization for 0.5h. After the reaction is completed, wash it repeatedly with distilled water and anhydrous ethanol to remove impurities. After drying or air drying, broadband electromagnetic wave stealth metamaterial is obtained, in which the polypyrrole molecular chain spacing is ~0.42nm.

[0092] Example 3

[0093] A method for preparing a broadband electromagnetic wave stealth metamaterial includes the following steps:

[0094] (1) Prepare a 1 ml solution of 0.5 wt% 4,4'-biphenyl dicarboxylic acid ethylene glycol and a 150 ml solution of 10 wt% Py(pyrrole) ethylene glycol. Mix the two solutions and stir at 20°C for 1 h to obtain mixed solution A.

[0095] (2) Prepare a 150 ml hydrogen peroxide ethylene glycol solution, then add zinc phthalocyanine copper tetrasulfonate and stir at room temperature for 2 h to obtain mixed solution B; wherein the concentration of hydrogen peroxide is 1 mol / L, and the mass ratio of 4,4'-biphenyl dicarboxylic acid to zinc phthalocyanine copper tetrasulfonate in step (1) is 30:1.

[0096] (3) Place the substrate film in an environment of 20°C until the surface temperature reaches 20°C. Then add mixed solution A and mixed solution B to two spray gun injection pumps respectively. Set the speed ratio of the injection pump of mixed solution A to the injection pump of mixed solution B to 5:1 and spray it onto the substrate surface. After all the solution is used up, place it in an environment of 20°C for 3 hours to polymerize. After the reaction is complete, wash it repeatedly with distilled water and anhydrous ethanol to remove impurities. After drying or air drying, broadband electromagnetic wave stealth metamaterial is obtained, in which the polypyrrole molecular chain spacing is ~0.35nm.

[0097] Example 4

[0098] A method for preparing a broadband electromagnetic wave stealth metamaterial includes the following steps:

[0099] (1) Prepare a 1 ml solution of 1,2-ethanedisulfonic acid dimethyl sulfoxide with a concentration of 10 wt% and a 120 ml solution of Py(pyrrole) dimethyl sulfoxide with a concentration of 20 wt%. Mix the two solutions and stir at 40 °C for 5 h to obtain mixed solution A.

[0100] (2) Prepare a 120 ml solution of copper chloride dimethyl sulfoxide, then add copper phthalocyanine tetrasulfonate and stir at room temperature for 2 h to obtain mixed solution B; wherein the concentration of copper chloride is 0.8 mol / L, and the mass ratio of 1,2-ethanedisulfonic acid to copper phthalocyanine tetrasulfonate in step (1) is 50:1.

[0101] (3) Place the triangular plastic substrate in a 40°C environment until the surface reaches 40°C. Then add mixed solution A and mixed solution B to two spray gun injection pumps respectively. Set the speed ratio of the injection pump of mixed solution A to the injection pump of mixed solution B to 3:1 and spray it onto the substrate surface. After all the solutions are used up, place it in a 40°C environment for polymerization for 5 hours. After the reaction is complete, wash it repeatedly with distilled water and anhydrous ethanol to remove impurities. After drying or air drying, broadband electromagnetic wave stealth metamaterial is obtained, in which the polypyrrole molecular chain spacing is ~0.42nm.

[0102] Comparative Example 1

[0103] A method for preparing a composite material differs from Example 1 only in that step (1) does not include the first intermediate 1,2-ethanedisulfonic acid. The remaining process steps and parameters are the same as in Example 1.

[0104] Comparative Example 2

[0105] A method for preparing a composite material differs from Example 1 only in that step (2) does not include the second intermediate PTSA. The remaining process steps and parameters are the same as in Example 1.

[0106] Comparative Example 3

[0107] A method for preparing a composite material differs from Example 1 only in that step (1) does not include the first intermediate 1,2-ethanedisulfonic acid, and step (2) does not include the second intermediate PTSA. The remaining process steps and parameters are the same as in Example 1.

[0108] Comparative Example 4

[0109] A method for preparing a composite material differs from Example 1 only in that the mass ratio of BPDSA to PTSA in step (1) is 10:1. All other process steps and parameters are the same as in Example 1.

[0110] Comparative Example 5

[0111] A method for preparing a composite material differs from Example 1 only in that the speed ratio of the injection pump for mixed solution A to the injection pump for mixed solution B in step (3) is 5:1. All other process steps and parameters are the same as in Example 1.

[0112] Technical effects:

[0113] 1. Performance Characterization

[0114] Figure 2 The image shown is an SEM image of the broadband electromagnetic wave stealth metamaterial obtained in Example 1. It can be seen that polypyrrole is uniformly loaded on the substrate.

[0115] Figure 5 The infrared spectrum of the broadband electromagnetic stealth metamaterial obtained in Example 3 shows that the wavelength of light reaching ~3400 cm⁻¹ is... -1 The red shift of the CN peaks on both sides indicates an increase in intermolecular forces.

[0116] Figure 6 The image shows the XRD pattern of the broadband electromagnetic wave stealth metamaterial obtained in Example 3. It can be seen that the electromagnetic wave stealth metamaterial has a more regular molecular chain structure and a narrower half-width at half-maximum.

[0117] 2. Light transmittance

[0118] use Figure 7 The device shown was used to detect the ultraviolet light transmittance of the broadband electromagnetic wave stealth metamaterial obtained in Example 4 and Comparative Example 5, and the results are as follows: Figure 8 As shown, the electromagnetic stealth metamaterial has the ability to shield against ultraviolet light, and it can be seen that changing the spraying speed is not conducive to the preparation of the metamaterial.

[0119] use Figure 9 The device shown detects the infrared transmittance of the broadband electromagnetic stealth metamaterial obtained in Example 4. The external ambient temperature is measured to be 40°C, and the internal ambient temperature is measured as follows: Figure 10 As shown, the lower the internal ambient temperature, the stronger the infrared shielding capability. The internal ambient temperature can be used to determine the shielding capability of electromagnetic stealth metamaterials against the infrared band.

[0120] 3. Dielectric constant detection

[0121] The detection method is as follows: After preparing the sample (solid or liquid), place it between the electrodes, start the instrument to perform a frequency scan, and record the data on the changes in dielectric constant and dielectric loss with frequency. After the measurement is completed, the analysis software generates a spectrum to reveal the polarization mechanism and electrical conductivity characteristics of the material.

[0122] Figure 3 The graph shows the dielectric constant of the broadband electromagnetic stealth metamaterial obtained in Example 2. It can be seen that the dielectric constant of the electromagnetic stealth metamaterial is negative.

[0123] 4. Electromagnetic conductivity detection

[0124] Test method reference: Place the sample inside or around the coil of the permeability meter, apply an AC or DC magnetic field, and measure the response of magnetic induction intensity or magnetization intensity. Analyze the measured data to calculate the sample's permeability and understand its magnetic characteristics.

[0125] Figure 4 The graph shows the electromagnetic conductivity results of the broadband electromagnetic wave stealth metamaterial obtained in Example 2. It can be seen that the magnetic permeability of the electromagnetic stealth metamaterial can be negative, especially at 1×10⁻⁶. 8 -2×10 8 The Hz range includes significantly negative permeability, while also combining Figure 3 The dielectric constant results indicate that the device possesses both negative dielectric constant and permeability within this frequency range, which could potentially enable stealth capabilities.

[0126] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A broadband electromagnetic wave stealth metamaterial, characterized in that, During the pyrrole polymerization process, intermediates are used to adjust the spacing between polypyrrole molecular chains, forming polypyrrole molecular chains arranged in a two-dimensional space. The interchain spacing of polypyrrole molecules is 0.25-0.45 nm; The intermediate includes a first intermediate and a second intermediate; The first intermediate includes one or any combination of 4,4'-biphenyl disulfonic acid, 1,2-ethanedisulfonic acid, 1,4-butanedisulfonic acid, 4,4'-biphenyl dicarboxylic acid, and 1,4-butanedicarboxylic acid. The second intermediate is a metal-organic ligand, wherein the metal ion in the metal-organic ligand includes one or any combination of sodium ions, zinc ions, iron ions, copper ions and silver ions; Includes the following steps: A mixed solution A of the first intermediate and pyrrole and a mixed solution B of the second intermediate and oxidant were simultaneously sprayed onto the substrate surface for polymerization reaction. After the reaction was completed, the substrate was cleaned to obtain the broadband electromagnetic wave stealth metamaterial. During the spraying process, the spraying speed ratio of mixed solution A to mixed solution B is 2:1 to 10:

1.

2. The method for preparing a broadband electromagnetic wave stealth metamaterial as described in claim 1, characterized in that, Includes the following steps: A mixed solution A of the first intermediate and pyrrole and a mixed solution B of the second intermediate and oxidant were simultaneously sprayed onto the substrate surface for polymerization reaction. After the reaction was completed, the substrate was cleaned to obtain the broadband electromagnetic wave stealth metamaterial. During the spraying process, the spraying speed ratio of mixed solution A to mixed solution B is 2:1 to 10:

1.

3. The method for preparing a broadband electromagnetic wave stealth metamaterial according to claim 2, characterized in that, The mixed solution A is obtained by mixing and stirring the first intermediate solution with the pyrrole solution; The concentration of the pyrrole solution is 0.5-20 wt%. The concentration of the first intermediate solution is 0.01-1 wt%. The volume ratio of the pyrrole solution to the first intermediate solution is (100-350):

1.

4. The method for preparing a broadband electromagnetic wave stealth metamaterial according to claim 2, characterized in that, In the mixed solution B, the concentration of the oxidant is 0.1-1 mol / L, the concentration of the second intermediate is 0.1-1.5 wt%, and the mass ratio of the second intermediate to the first intermediate is 1:(3-50).

5. The method for preparing a broadband electromagnetic wave stealth metamaterial according to claim 4, characterized in that, The oxidant is one or any combination of ferric oxide, ammonium persulfate, copper chloride, or hydrogen peroxide.

6. The method for preparing a broadband electromagnetic wave stealth metamaterial according to claim 2, characterized in that, The polymerization reaction is carried out at a temperature of -5 to 40°C for a duration of 0.5 to 9 hours.

7. The application of the broadband electromagnetic wave stealth metamaterial as described in claim 1 in the fields of electromagnetic shielding, electromagnetic stealth, sensors, or smart touch conduction.

Images