34results about How to "Guaranteed absorption effect" patented technology

The invention belongs to the field of material preparation, in particular to a light-weight hollow carbon cube wave-absorbing material and a preparation method thereof. The present invention aims to solve the problems of the impedance mismatch and the non-adjustable electromagnetic wave absorption frequency band of the pure carbon absorbing material prepared by the existing method. On the basis of making full use of the hard template to construct the hollow structure, a light-weight hollow carbon cube absorbing material is proposed. The method of preparation of the material. The present invention selects Cu 2 O microspheres are hard templates, and light hollow carbon cubes are obtained by in-situ growth, calcination, template removal and other processes. By adjusting Cu 2 The coating thickness of the polydopamine precursor on the O surface can be used to control the shell thickness of the hollow carbon cube, which can realize the effective regulation of the electrical conductivity of the carbon material in a small range, and can also obtain suitable wave-absorbing materials according to the needs, which is conducive to improving Impedance matching and absorbing effect of materials. The development of lightweight hollow carbon cube absorbing materials is expected to be applied in the field of building absorbing materials.

The invention provides a double-layer conductive thin film-based transparent broadband electromagnetic wave absorber and aims at solving the technical problem of a narrow application range of an existing wave absorber. The double-layer conductive thin film-based transparent broadband electromagnetic wave absorber comprises a conductive thin film, a first dielectric layer, a second dielectric layer, a third dielectric layer and a bottom plate, wherein transparent dielectric plates are adopted as the first dielectric layer and the third dielectric layer; the transparent dielectric plate or an air dielectric is adopted as the second dielectric layer; the three dielectric layers are arranged from top to bottom to form the dielectric layers with a stacked structure; a transparent conductive thin film is adopted as the bottom plate and is printed on the lower surface of the third dielectric layer; and the conductive film is formed by compounding m*n arrays formed by square transparent conductive thin films and (m+1)*(n+1) arrays formed by cross-shaped transparent conductive thin films and is printed on the upper surface of the first dielectric layer. High light transmission is achieved while the wave absorption bandwidth and the wave absorption rate are ensured; and the double-layer conductive thin film-based transparent broadband electromagnetic wave absorber can be applied to electromagnetic anti-interference of microwave systems, of aircraft cabin glass, a PCB-based novel inter-chip wireless interconnection system and the like, requiring the high light transmission.

The invention relates to a low-frequency P-band wave-absorbing material and a preparation method thereof. The method includes: using a first surfactant to modify the graphene powder to obtain a functionalized graphene dispersion; using a high-energy ball milling method to compound the functionalized graphene dispersion with spherical magnetic alloy particles to obtain a Functionalized graphene / flaky magnetic alloy particle composite absorbent; using a second surfactant to coat the composite absorbent to obtain a low-frequency P-band absorbent; combining the low-frequency P-band absorbent with EPDM After the rubber is mixed, the low-frequency P-band wave-absorbing material is obtained through rubber mixing and calendering processes. The present invention provides a new idea for expanding the low-frequency P-band wave-absorbing material. The effective absorption bandwidth of the wave-absorbing material prepared by the present invention can be flexibly adjusted within the range of 0.3-1.0GHz wave band according to needs, and at the same time, the material has better Mechanical and construction properties, easy to bond to the surface of various structural parts.

The invention relates to a functionalized graphene / polymethacrylamide composite wave-absorbing material and a preparation method thereof. The preparation method comprises the following steps: (1) mixing graphene, resin, a modifier, a coupling agent, a dispersing agent, a wetting agent and an organic solvent uniformly to obtain functionalized graphene slurry; wherein the modifier is selected from one or more of KH550, KH560 and KH570, and the mass of the modifier is 1-5% of the mass of the graphene; the coupling agent is selected from one or more of TMC-101, TMC-102 and TMC-201, wherein the mass of the coupling agent is 0.5-2% of the mass of the graphene; (2) mixing the functionalized graphene slurry with a foaming liquid; (3) pre-polymerizing; and (4) polymerizing. The product prepared bythe method is reliable in performance and stable in quality, not only can the effect of absorbing electromagnetic waves, but also also has the advantages of light weight, wide frequency and easiness in processing.

The invention discloses a scaling-theory-based design method of high-performance absorber. The method comprises: S1, on the basis of a prototype wave-absorbing material, corresponding electromagneticparameters and a corresponding prototype frequency are obtained, wherein the electromagnetic parameters include a dielectric constant and a magnetic permeability; S2, according to a reflectivity calculation theory of multi-layer materials, impedance characteristics and changing rule functions of all layers of materials are analyzed by combining the electromagnetic parameters and the prototype frequency of the prototype wave-absorbing material, thereby obtaining an impedance characteristic function; and on the basis of a scaling theory, a scaling material having the shape same as the prototypewave-absorbing material is prepared and scaling electromagnetic parameters and thicknesses of all layers of materials are theoretically designed based on the impedance characteristic parameters; S3, ascaling frequency coefficient and a shape ratio factor are determined to obtain a material prescription meeting the impedance characteristic; and S4, a needed high-performance absorber is constructedby using the material prescription. The method has the following advantage: the quick design of a broadband absorbing material is realized.

The invention relates to a cable wave absorbing layer coating system and a coating method thereof. The system comprises a thread releasing shaft, two coating devices, two sintering furnaces, three guide wheels, a traction wheel and a thread drawing shaft, and each coating device comprises a thread passing mold, a liquid storage tank and a liquid scraping mold, wherein the thread passing mold and the liquid scraping mold are fixed on the bottom and the top of the liquid storage tank via a fastening flange and a rubber sealing ring, respectively; the upper end of the liquid storage tank is provided with a liquid adding hole, and the middle of the liquid storage tank is provided with a transparent window. By adopting the system, a cable is coated twice, and is sintered twice, and a coating liquid is formed by mixing a certain amount of Teflon suspension emulsion, graphene, distilled water and triton; the temperature of each sintering furnace is controlled to be within the range of 180 DEG C-320 DEG C; the traction speed is 10-12m / min. By adopting the system, the low-noise cable wave absorbing layer is coated; by a twice-coating and twice-sintering technology, the wave absorbing layer is coated uniformly and firmly so as to guarantee the cable wave absorbing effect. Meanwhile, the cable wave absorbing layer coating system and the coating method thereof have the characteristics of high coating efficiency, good uniformity and consistence and the like.

The invention discloses a composite wave-absorbing material based on 3D printing and its application, and belongs to the technical field of building materials; the composite wave-absorbing material based on 3D printing includes a main printing material; the main printing material includes the following components by weight: ordinary silicate 30-90 parts of cement, 0-20 parts of sulphoaluminate cement, 0-20 parts of fly ash, 0-20 parts of silica fume, 5-60 parts of solid waste from sludge power plants, 60-200 parts of quartz sand or river sand 0-50 parts of wave-absorbing aggregate, 0.3-5 parts of water reducing agent, 20-50 parts of water, 0-3 parts of flexible chopped fiber, and 0-30 parts of wave absorbing agent. The present invention uses power plant fly ash and tailings to replace part or all of the wave absorbing agent, which can simultaneously ensure the wave absorbing effect and mechanical strength of the 3D printed composite wave absorbing material.