73 results about "Broadband absorption" patented technology

The invention discloses a metasurface array antenna housing, belongs to the technical field of electromagnetic wave regulation and control, and solves the problem of how to improve the transmittance and absorptivity of a metasurface to electromagnetic waves. Electromagnetic waves with different frequencies resonate on the first metasurface wave-absorbing layer and the second metasurface wave-absorbing layer respectively, so that the electromagnetic waves are absorbed by the lumped resistor. And the metasurface wave-transmitting layer re-radiates electromagnetic waves of a communication frequency band to enable the electromagnetic waves to penetrate through the metasurface unit, and meanwhile, the surface of the metasurface wave-transmitting layer can serve as a metal floor of the first metasurface wave-absorbing layer and the second metasurface wave-absorbing layer due to copper coating. The antenna can be widely used in the scenes of radar stealth, communication antenna integration, electromagnetic compatibility, wireless energy transmission and the like, and has a good application prospect.

The invention discloses a multifunctional broadband metamaterial structure with a polarization independent characteristic and a control method. The structure has a switchable tri-state function and a complete polarization operation capability irrelevant to polarization. By introducing the guide circuit design, three different electromagnetic energy regulation and control modes of second-order filtering, broadband absorption and multi-reflection shielding are efficiently integrated in the same structure, the real broadband performance in the band is realized, and meanwhile, the higher reflection efficiency outside the band is kept. Different from a traditional method which depends on a broadband lossless reflecting layer to expand the transmission bandwidth of an absorption structure, the three arrays are considered as an integral operating system, support three-state switching operation and have real broadband and efficient behaviors.

A broadband low-transmittance and high-absorption wave absorption and transmission integrated frequency selection surface comprises three wave absorption layers and two wave transmission layers which are sequentially stacked from top to bottom, and the three wave absorption layers are sequentially divided into an upper wave absorption layer, a middle wave absorption layer and a lower wave absorption layer from top to bottom; the two wave-transparent layers are sequentially divided into an upper wave-transparent layer and a lower wave-transparent layer from top to bottom; the multi-layer composite structure design is adopted, collaborative optimization of the wave absorbing performance and the wave transmitting performance is achieved by combining the two wave transmitting layers on the lower portion and the three wave absorbing layers on the upper portion, through organic combination of the upper layer structure and the lower layer structure, dual performance improvement of broadband wave absorbing and broadband wave transmitting is achieved, and a transition zone between a wave absorbing zone and a wave transmitting zone is greatly reduced.

The invention discloses a polarization sensitive type broadband absorber based on metal-medium stacking, and relates to the technical field of micro-nano photonic devices and infrared detection. The absorber sequentially comprises a bottom-layer high-loss metal reflecting layer, a multi-layer stacked composite dielectric cavity structure and a top-layer sub-wavelength metal grating from bottom to top, according to impedance matching and interference resonance theories, a broadband absorption substrate is constructed through a multi-layer film structure at the bottom, and light energy is converted into heat energy by utilizing the high loss characteristic of bottom layer metal; plasmon resonance is excited through the top metal grating, the coupling efficiency of TM polarized light is enhanced, and TE polarized light is cut off; the above structural design successfully realizes efficient broadband absorption and high polarization extinction ratio in an infrared band. The structure is simple in design, is compatible with a CMOS technology, and has excellent wide-angle stability. And meanwhile, polarization screening can be realized without an external polaroid, and miniaturization and integration of an infrared detection system are facilitated.

The application claims a kind of multiband terahertz absorber based on laminated graphene structure, which is a laminated stack structure.The positive terminal of external power supply is connected to two layers of graphene, and the negative terminal is connected to a gold reflection layer.The Fermi energy level of graphene is controlled by voltage.The structure parameters of each layer, graphene and dielectric layer material characteristics are set.The absorber forms multiple absorption peaks in the 1~5 THz frequency band, with a peak absorption rate of over 90%.At 1.60 THz, a narrowband absorption of 93% is achieved, and at 2.54~4.28 THz, a broadband absorption with a relative bandwidth of 51% is achieved.The normalized equivalent impedance at the resonance frequency point is nearly perfectly matched with the free space impedance.The absorber also has good polarization angle insensitivity, with only slight absorption performance attenuation within an incident angle range of 0~60°.The absorption characteristics can also be adjusted by adjusting the key geometric parameters.The application can simultaneously achieve narrowband and broadband absorption, with excellent absorption performance, and is suitable for interference signal filtering in terahertz communication systems.

This invention relates to a method for preparing a broadband absorption hydrogel. The method comprises the following steps: S1, mixing solvent A (N,N-dimethylformamide or acetonitrile) with deionized water to obtain a mixed solvent; S2, adding polyethylene glycol methyl ether acrylate-480 and acryloylmorpholine to the solvent in S1 and dissolving them to obtain a mixed solution; S3, removing dissolved oxygen from the mixed solution in S2, sealing the container, and stirring under ice bath conditions; S4, adding potassium persulfate and N,N,N',N'-tetramethylethylenediamine to the mixed solution after stirring in S3, and sealing the container again; S5, completing the polymerization reaction in the container at 60 °C to obtain the hydrogel. Compared with the prior art, the hydrogel material provided by this invention has improved reflection loss intensity and effective absorption bandwidth performance, thus providing a new perspective for developing highly flexible and efficient electromagnetic wave absorbers.

This invention discloses an integrated energy-selective metasurface for electromagnetic shielding and absorption, belonging to the field of electromagnetic protection technology. It comprises a first substrate dielectric substrate, a first metal circuit structure printed on the upper surface of the first substrate dielectric substrate, a second metal circuit structure printed on the lower surface of the first substrate dielectric substrate, a second substrate dielectric substrate, and a third metal circuit structure printed on the upper surface of the second substrate dielectric substrate. The energy-selective metasurface of this invention exhibits energy selectivity in two frequency bands: 1.92GHz–2.05GHz and 4.40GHz–4.46GHz, allowing low-power signals to transmit while reflecting or blocking high-power electromagnetic energy; and achieves a broadband absorption effect with an absorption rate exceeding 95% in the X-band. This invention integrates multi-band energy-selective protection and broadband high-efficiency absorption functions into one device.

The present application relates to the field of optical technology, more particularly to a visible to mid-infrared super-wideband absorber and a preparation method thereof, the method comprising the following steps: self-assembling polystyrene microspheres on a polyimide substrate to form a monolayer hexagonal close-packed structure substrate, and then forming a nano-cone array substrate through ion etching; placing a copper substrate into a coating chamber and introducing argon, and sputtering to obtain a reflection layer; placing a zirconium substrate into the coating chamber and introducing argon and oxygen, and sputtering to obtain a first metal absorption film layer; continuously introducing argon and oxygen, and sputtering to obtain a second metal absorption film layer; continuously introducing argon and oxygen, and sputtering to obtain a third metal absorption film layer; placing an aluminum oxide substrate into the coating chamber, and then introducing argon, and sputtering to obtain a dielectric antireflection layer, thereby forming the absorber. The present application can have extremely high absorption in the visible light and near-infrared regions, and has good angle tolerance, polarization insensitivity, bending resistance and heat resistance.

This invention discloses a broadband duct silencing structure combining perforated tubes and cavities. The structure uses a galvanized housing as its main body, with perforated tubes coaxially arranged inside. A perforated partition divides the structure into front and rear silencing chambers. The front silencing chamber contains a first sound absorber and an air layer, forming a Helmholtz resonant cavity to efficiently eliminate low-frequency fan noise. The rear silencing chamber is filled with a second sound absorber and is equipped with perforated tubes, micro-perforated tubes, and micro-perforated inserts with progressively smaller apertures, forming a gradient microporous structure to achieve broadband absorption of mid-to-high frequency noise. The structure utilizes the airflow in the duct to drive the impeller to rotate, which in turn drives a bidirectional reciprocating screw via bevel gear transmission. This drives a delivery rod and a one-way valve to form a directional airflow circulation. The sound absorber is automatically purged through the air duct and comb-shaped air duct to remove fiber dust, preventing secondary pollution and stabilizing acoustic performance. This invention combines the advantages of low-frequency resonance silencing and mid-to-high frequency gradient microporous sound absorption, featuring a compact structure, wide silencing bandwidth, and stable and reliable operation.

The invention discloses a low-profile band-pass frequency selective wave-absorbing surface with broadband wave absorption. The low-profile band-pass frequency selective wave-absorbing surface comprises a resistance loss layer, an air layer and a band-pass FSS transmission layer in sequence from top to bottom, the resistance loss layer comprises a first dielectric substrate, a central metal sheet is printed at the center of the upper surface of the first dielectric substrate, an etching groove is etched in the central metal sheet, a parallel LC resonance circuit is formed through the etching groove, the periphery of the central metal sheet is connected with metal bridge arms which are symmetrically distributed in a central rotation mode and extend outwards, and the metal bridge arms are connected with the first dielectric substrate. The tail end of each metal bridge arm is connected with a circular metal sheet which takes the midpoint of the tail end of the metal bridge arm as a circle center, and lumped resistors are loaded on the metal bridge arms; through the single resistance loss layer, loading of the lumped resistor and special slotting of the resistance loss layer, broadband wave absorption with a band-pass window can be realized by using a two-dimensional structure, and the broadband wave absorption device has the characteristics of low profile, easy processing, flexible regulation and control and the like.

The invention discloses a preparation method of an aramid nanofiber / graphitized multi-walled carbon nanotube composite fiber woven body, and belongs to the technical field of electromagnetic wave absorbing materials. According to the invention, the effective loss of electromagnetic wave energy and the cooperative improvement of broadband absorption performance are realized. The method comprises the following steps: by taking aramid nano-fibers as a framework and graphitized multi-walled carbon nanotubes as a loss medium, constructing composite fibers with a microscopic three-dimensional conductive network structure through a wet spinning and sol-gel conversion process, and weaving the fibers to obtain a composite fiber woven body with a macroscopic conductive network. According to the invention, efficient loss and broadband absorption of electromagnetic waves are realized. The method is simple in technological process, low in cost, high in controllability, capable of achieving continuous production and high in industrial feasibility, and the product has high electromagnetic wave loss capacity and wide electromagnetic wave absorption bandwidth. The method is applied to the field of electromagnetic wave absorbing materials.

According to the invention, the existing MR organic molecules are used in the anti-blue light product, so that not only are the defects of broadband absorption, low light transmittance, color cast, instability and the like of the traditional absorption type anti-blue light material improved, but also the overall light stability and durability are improved by utilizing the structural advantages of the MR molecules. The blue-light-resistant transparent base material achieves precise narrow-band protection, long-term stable protection, excellent color reducibility and good compatibility with existing transparent base materials, and is suitable for various blue-light-resistant products such as spectacle lenses, screen protection films, vehicle-mounted glass, lighting lampshades and VR / AR optical elements.

The utility model discloses a metasurface structure for reducing normal incident scattering of an antenna, and the metasurface structure employs a double-layer design, combines an absorption layer and a frequency selection surface layer, and achieves broadband absorption through a periodically two-dimensional unfolded microstrip patch unit and a three-layer resistor loading metal ring. Ansys electromagnetic field simulation software verifies that the structure effectively reduces the radar cross section of the microstrip antenna within the frequency band of 3-10 GHz, and ensures the normal work of the antenna at the same time. Through deep analysis and simulation optimization, key factors influencing the performance are determined, and the balance between the wave permeability and the wave absorbing property is realized. Besides, an adjustable resistance circuit, a reconfigurable mechanism, an intelligent algorithm and a sensor technology are integrated, the stability and the automation level of the antenna performance are further improved, and an effective solution is provided for improving the scattering reduction effect during forward incidence of radar waves.

A method for attaching and detaching electronics structures during integrated circuit manufacturing is disclosed. A stack is formed including a carrier and an electronics structure. Between the carrier and electronics structure, a broadband absorber layer is provided. The broadband absorber layer includes broadband absorber material and polymer. A layer of ultraviolet (UV) light curable adhesive is also provided between the carrier and the electronics structure. UV light is directed through the carrier in order to cure the UV curable adhesive. The electronics structure can be processed while secured to the carrier. The electronics structure is removable from the carrier by transmitting a light pulse from a flashlamp through the carrier to heat the broadband absorber layer. The heat can decompose the polymer to permit removal of the electronics structure from the carrier.

This invention provides a diazobiphenyl dye for thin-film polarizers, which is an analog of AD1. Thin-film polarizers prepared using this dye exhibit good optical quality, such as low light scattering, high dichroism ratio, broadband absorption, and / or stability to heat and light irradiation. This invention also provides a method for preparing the diazobiphenyl dye from two different monoazo dyes via a cross-coupling reaction. This method is eco-friendly because it does not use toxic benzidine as a raw material. The product (diazobiphenyl dye) obtained by this method can be purified in a simple and convenient manner, and the diazobiphenyl dye prepared by this method can have a symmetrical or asymmetrical structure. Furthermore, this invention provides a thin-film polarizer comprising the diazobiphenyl dye and an apparatus for display applications comprising the thin-film polarizer.

The invention relates to the technical field of dichroic dyes, and particularly provides a total anthraquinone type black dichroic dye, a guest-host liquid crystal composition containing the total anthraquinone type black dichroic dye and application of the total anthraquinone type black dichroic dye. The total anthraquinone type black dichroic dye provided by the invention comprises an anthraquinone type orange dye, an anthraquinone type red dye and an anthraquinone type blue dye, each of the anthraquinone orange dye, the anthraquinone red dye and the anthraquinone blue dye comprises a structural formula as shown in a formula (1). The total anthraquinone type black dichroic dye provided by the invention shows remarkable absorption in a visible light broadband range of 400-650nm, not only covers a main interval from purple light to red light, but also keeps relatively stable absorbance in the broadband, and shows broadband absorption characteristics; meanwhile, the average dichroic ratio can reach 11.28, and the optical performance is excellent; and the material also has excellent switching performance between a black opaque state and a transparent state, and can realize rapid reversible switching between the two states under the action of an electric field.

The invention provides a broadband metasurface wave absorber based on an oblique symmetric mosaic structure. The broadband metasurface wave absorber comprises a metal resonance layer, a dielectric layer and a metal reflecting layer which are sequentially stacked, the metal reflecting layer is formed by two inlaid structures which are arranged in an oblique symmetry mode, each inlaid structure comprises a semi-square ring body and a semi-circular ring body wrapping the outer side of the semi-square ring body, and two edge protruding edges of each semi-square ring body are connected with the corresponding semi-circular ring body; the semi-square ring body and the semi-circular ring body are both of an open structure, and the opening directions of the semi-square ring body and the semi-circular ring body are the same. According to the wave absorber disclosed by the invention, a broadband absorption effect on electromagnetic waves in a frequency band of 9.43 GHz to 14.95 GHz is realized; meanwhile, within the absorption frequency band, the absorption rate of electromagnetic waves reaches 90% or above, and the absorption rate of electromagnetic waves reaches 99% or above near two resonance peak values of 10.02 GHz and 13.56 GHz.

This application relates to the technical field of microwave absorbing materials, and in particular to a high-power electromagnetic compatibility (EMC) composite microwave absorbing material and its preparation method. The high-power EMC composite microwave absorbing material comprises an aramid paper honeycomb core and a microwave absorbing resin composite solution coated on the surface of the aramid paper honeycomb core. The microwave absorbing resin composite solution comprises the following raw materials in parts by weight: 2-7 parts microwave absorber, 30-40 parts solvent-based binder, 1-5 parts dispersant, 0.1-0.8 parts additives, and 50-65 parts solvent. The high-power EMC composite microwave absorbing material prepared by this application has the advantages of withstanding high-power radiation, good broadband absorption performance, and stable product performance, meeting the core requirements of EMC anechoic chambers for microwave absorbing materials.

This invention relates to a method for preparing Ag₂O-Bi₄O₅I₂ broadband absorption heterojunction photocatalyst and its application in microreactors, belonging to the field of photocatalyst preparation technology. This invention utilizes a chemical precipitation method to support broadband-absorbing Ag₂O on the surface of Bi₄O₅I₂ nanosheets, constructing a heterojunction to achieve separation of photogenerated carriers. The prepared Ag₂O-Bi₄O₅I₂ composite material also exhibits excellent broadband absorption. The composite with Ag₂O nanoparticles further increases the reactive sites on the Bi₄O₅I₂ nanosheets, further enhancing its photocatalytic performance. Coating it onto a glass surface to prepare a microreactor increases the heating rate and reaction temperature of the photothermal catalyst in liquid-phase catalysis, improving the photocatalytic degradation effect. The composite material prepared by this invention shows good performance in the photocatalytic degradation of tetracycline, helping to solve the current problem of excessive antibiotics that are difficult to degrade in wastewater.

The invention provides a polarization-independent switchable frequency selective absorption transmitter. The polarization-independent switchable frequency selective absorption transmitter comprises a loss layer and a switching layer, the loss layer and the switching layer are distributed up and down, and an air spacing layer is arranged between the loss layer and the switching layer; the loss layer comprises a first dielectric substrate, an upper loss layer and a lower loss layer, the upper loss layer and the lower loss layer are attached to the upper surface and the lower surface of the dielectric substrate respectively, and the upper loss layer and the lower loss layer are distributed orthogonally; the switching layer comprises a second dielectric substrate, a metal layer and four PIN diodes; the metal layer is attached to the upper surface of the second dielectric substrate, the metal layer is provided with a square annular gap, and the four PIN diodes are all arranged in the square annular gap. The loss layer and the lower loss layer are in a Z-shaped structure in central symmetry and comprise two interdigital structures. According to the invention, stable switching of two modes of absorption-transmission-absorption and absorption-reflection-absorption can be realized, characteristics of broadband absorption, low insertion loss and polarization independence are realized, and the adaptability to a complex electromagnetic environment is improved.

This invention belongs to the field of metamaterials technology, specifically relating to an adjustable integrated absorption and reflection metamaterial structure. It includes several basic units arranged in a periodic array. Each basic unit comprises a resonant unit, a dielectric layer, and a reflector layer stacked sequentially. The dielectric layer is deformable to create a cavity between itself and the reflector layer or to fit tightly against it. The resonant unit includes four sequentially connected arc-shaped segments arranged centrally symmetrically. The ends of adjacent arc-shaped segments connect to form sharp corners extending towards the center of the resonant unit, with a gap between opposing sharp corners. This invention offers good reconfigurability, high flexibility, and deformability, allowing for easy adjustment of the state and switching of operating modes according to actual usage needs, achieving broadband absorption or complete reflection functions from 4.9 GHz to 16.3 GHz.

The invention discloses a polyethersulfone ketone-based high-temperature-resistant wave-absorbing composite film, which belongs to the technical field of functional composite materials, the composite film has a compact continuous phase structure, and mainly comprises the following components in percentage by mass: 28-50% of polyethersulfone ketone resin used as a continuous matrix, and the balance of a wave-absorbing agent tightly wrapped by the polyethersulfone ketone resin. The mass percent of the wave absorbing agent is 50-72%. According to the composite film, the polyethersulfone ketone resin is used as a matrix, anti-oxidation protection can be achieved without complex surface pre-coating of a wave absorbing agent, and the composite film has excellent thermal stability, good dispersity and film forming quality and ultra-thin broadband absorption. Meanwhile, the invention further provides a preparation method of the composite membrane, sedimentation of the wave-absorbing agent is effectively inhibited through a specific solvent ratio and a gradient curing process, the preparation method is simple and high in operability, and the technical problem that high temperature resistance, ultra-thinness and broadband absorption are difficult to achieve at the same time can be solved only by using a simple casting process.

The application relates to a preparation method of a SiC absorbing-transmitting laminated wave-absorbing coating and belongs to the technical field of electromagnetic wave absorbing materials. The application aims at solving the problems that the existing wave-absorbing materials cannot simultaneously satisfy impedance matching and rapid absorption and cannot satisfy low-frequency broadband absorption. The method comprises the following steps: 1, mixing cobalt oxide, silicon powder, silicon dioxide powder and carbon powder; 2, calcining and high-temperature carbon removal; 3, preparing coating I; 4, preparing coating II; and 5, coating. The application is used for the preparation of the SiC absorbing-transmitting laminated wave-absorbing coating.

The invention relates to the technical field of electromagnetic shielding composite materials, in particular to a composite material beneficial to shielding of electromagnetic interference of an engine of an unmanned aerial vehicle and a preparation method thereof.The composite material is of a five-layer structure, the outer layer is a high-permeability absorption layer and is 0.8-1.2 mm thick, the inner layer is an impedance transition layer and is 0.5-0.8 mm thick, and the composite material is composed of polyimide, silicon carbide whiskers and flaky carbonyl iron powder; the broadband absorption layer is arranged inwards, the thickness of the broadband absorption layer ranges from 1.5 mm to 2.5 mm, polyether-ether-ketone serves as a matrix, manganese zinc ferrite, carbon nanotubes and graphene are compounded, the metal reflection layer with the thickness ranging from 0.3 mm to 0.6 mm is arranged on the inner side of the broadband absorption layer, an alloy thin plate with specific roughness is adopted, the carbon fiber reinforced protection layer is arranged on the innermost layer, the thickness of the carbon fiber reinforced protection layer ranges from 0.8 mm to 1.5 mm, and the carbon fiber reinforced protection layer is formed by compounding carbon fibers and epoxy resin and provides structural support; by adjusting the characteristic impedance of the material layer by layer, the step-by-step attenuation of electromagnetic waves is realized, and the interface reflection is minimized.

Provided in the present invention are a method for designing a causally optimal broadband acoustic metamaterial sound absorber, and a sound absorber. A new method for designing and manufacturing a metamaterial sound absorber to realize causally optimal broadband absorption (COBA) is introduced. The method involves three key steps: (1) calculating a COBA spectral line by means of solving an optimization problem based on a causal constraint; (2) designing a resonator array, the modal density and resonance strength of which match the COBA spectral line; and (3) using a mass production method, such as a mold forming process, to manufacture a sound absorber. As a result, compared with conventional porous sound absorbers, a produced acoustic metamaterial sound absorber shows a better broadband absorption performance under a given thickness constraint, particularly within a low frequency range. The present invention represents a significant advancement in the development of a high-performance and space-saving noise control solution.

This invention belongs to the field of frequency-selective surfaces and electromagnetic absorption materials, and relates to a broadband low-pass frequency-selective absorber. It comprises multiple structural units arranged in a rectangular array. Each structural unit includes an absorption layer, a first transmission layer, a second transmission layer, and a third transmission layer, sequentially arranged and fixedly connected by insulating connecting pillars. Support structures are provided between adjacent layers, correspondingly forming foam layers one, two, and three. The absorption layer includes a first dielectric substrate and a loss-absorbing structure thereon. The first transmission layer includes a second dielectric substrate and a first metal square ring structure thereon. The second transmission layer includes a third dielectric substrate and a spiral metal strip structure thereon. The third transmission layer includes a fourth dielectric substrate and a second metal square ring structure thereon. This invention features a small unit structure size and low profile, achieving low insertion loss transmission in the low-frequency band, broadband absorption in the high-frequency band, and stable performance under large-angle incident light.

The invention relates to the technical field of electromagnetic wave absorption devices, in particular to a multifunctional metamaterial perfect absorber and a manufacturing method thereof. The invention provides a multifunctional metamaterial perfect absorber and a manufacturing method thereof. The absorber comprises a silicon substrate layer, an adhesion chromium layer, a silicon dioxide thin film spacing layer, a gold thin film spacing layer, a broadband absorption metasurface and a narrowband absorption metasurface. The zirconium nitride concentric ring array is arranged on the broadband absorption metasurface, and the average absorption rate in the visible to near-infrared region wave band is as high as 97.48%; the narrow-band absorption metasurface is provided with a 4 * 4 grid array formed by zirconium nitride, and has 99.99% ultrahigh narrow-band absorption and high refractive index sensitivity. The material has excellent refractive index sensing performance and high thermal chemical stability of the zirconium nitride material, is suitable for the fields of solar energy collection, biosensing, environmental protection and the like, and remarkably improves the energy collection efficiency and the sensing sensitivity.

The application belongs to the field of micro-nano photonics and infrared sensing, and relates to an infrared broadband absorption metasurface structure. A structure of metal layer-dielectric layer-metal layer is adopted, the upper and lower metal layers adopt platinum, the dielectric layer uses traditional material silicon, and array arrangement is realized by combining different size sub-units, an infrared broadband absorption metasurface based on a square bevel structure is designed, and an average absorption rate of more than 60% in the 8-13um atmospheric window band is realized. The bottom metal and the dielectric layer are uniform layer structures, and the top metal layer adopts a square bevel of one angle, the ratio of the bevel to the square side length is related to the absorption wavelength. The application regulates the light field based on micro-nano structure parameter change, has good wavelength selectivity and modulation performance, the selected material has good chemical stability, and has practicability and process compatibility.

The invention belongs to the field of electromagnetic wave absorbing materials, and discloses an MXene sphere and cobalt / carbon core-shell composite wave absorbing material and a preparation method and application thereof. The material takes a hollow MXene sphere as a core, and ZIF-67 is grown and pyrolyzed on the surface of the hollow MXene sphere in situ to form a unique core-shell structure. The preparation method comprises the following steps: (1) dispersing MXene (Ti3C2Tx) and a spherical polymethyl methacrylate (PMMA) template, and then freeze-drying to obtain composite aerogel; (2) carrying out heat treatment in an inert atmosphere to remove the template so as to obtain hollow MXene spheres; (3) reacting the hollow spheres with Co (NO3) 2.6 H2O and 2-methylimidazole in methanol, and washing and drying to obtain a precursor; and (4) pyrolyzing to obtain the final composite material. According to the structure, MXene interlayer stacking is inhibited, the specific surface area is increased, dielectric loss and impedance matching are optimized, the minimum reflection loss of the material within the frequency band of 2-18 GHz reaches-57.5 dB, and the broadband absorption characteristic is achieved. The material is low in density, excellent in wave absorbing performance and suitable for the fields of aerospace stealth coatings, 5G communication protection, flexible electronics and the like.

The application provides a display structure, which comprises a narrow-band absorber structure and a wide-band absorber structure. The wide-band absorber structure comprises a film formed by a dielectric layer and a metal layer. The metal layer is multilayered and has a loss and a K value greater than a preset threshold. The wide-band absorber structure is located above the narrow-band absorber structure and coupled with the narrow-band absorber structure to generate bright colors. In the wide-band absorber structure, the multilayered metal layer with a high K value can inhibit reflectivity of non-target wave bands, so that rich colors can be generated and the purity of the colors can be improved. The structure assembly has the advantages of simple structure, resistance to environmental influence, angle insensitivity and the like.