74results about How to "Excellent electromagnetic wave absorption performance" patented technology

The invention discloses a wave-absorbing foam / honeycomb core composite board as well as a preparation method and application thereof. Comprising a honeycomb core substrate layer, a wave-absorbing foam embedding layer and a wave-transparent foam filling layer which are sequentially stacked, the honeycomb core substrate layer is a honeycomb core with a plurality of through hollow areas, and each surface of the honeycomb core is provided with a wave-absorbing coating; the wave-absorbing foam embedded layer comprises a plurality of filling parts and protruding parts, the hollow area of the honeycomb core substrate layer is filled with the filling parts, and the protruding parts are arranged on the surface of the honeycomb core substrate layer in a protruding mode and form a fluctuating structure; the wave-absorbing foam embedded layer is made of a wave-absorbing material; the wave-transparent foam filling layer is filled in the protruding parts, and a flat surface is formed on the side, away from the honeycomb core substrate layer, of the wave-transparent foam filling layer. The low-frequency absorption performance is improved on the premise that the total thickness is not increased, the multiple wave-absorbing characteristics of the wave-absorbing foam embedded layer are reserved, and meanwhile the excellent performance of the plane plate in the aspects of bearing, cutting and splicing is ensured.

One embodiment of the present invention relates to a thermoplastic resin composition for electromagnetic wave absorbers, which contains a thermoplastic resin (A), carbon nanotubes (B) having an average diameter of 1-15 nm, and carbon black (C) having an average primary particle diameter of 20-50 nm, and satisfies any one of (i)-(iv), in which [Delta] RL represented by formula (1) is 3 dB or less, and [Delta] TL represented by formula (2) is 5 dB or less.

The invention belongs to the technical field of wave-absorbing materials, and particularly relates to a monatomic modified carbon composite wave-absorbing material and a preparation method thereof. The method specifically comprises the following steps: S1, uniformly dispersing a pyrrole monomer and molybdenum trioxide hydride by using a solvent, and reacting at room temperature for 3-6 hours to obtain an HM-PPy compound; s2, adding metalloporphyrin and thionyl chloride into N, N-dimethylformamide, uniformly mixing, and then adding 4-dimethylaminopyridine to obtain a raw material solution; s3, dispersing the HM-PPy compound into a N, N-dimethylformamide solution containing triethylamine, so as to obtain a turbid liquid; s4, dropwise adding the raw material solution into the turbid liquid, and stirring and reacting at room temperature for 20-25 hours to obtain HM-PPy-MPor; and S5, carrying out pyrolysis on the HM (at) PPy-MPor to obtain the monatomic modified carbon composite wave-absorbing material.

The invention discloses a liquid metal-manganese oxide-MXene wave-absorbing phase change composite particle as well as a preparation method and application thereof. The liquid metal-manganese oxide-MXene wave-absorbing phase-change composite particle comprises a liquid metal inner core, a manganese oxide middle shell layer and an MXene outer coating layer. The preparation method comprises the following steps: 1) preparing the liquid metal-manganese oxide composite particle; 2) preparing surface modified liquid metal-manganese oxide composite particles; and 3) electrostatic adsorption coating of MXene on the surfaces of the surface modified liquid metal-manganese oxide composite particles. The liquid metal-manganese oxide-MXene wave-absorbing phase-change composite particle has excellent electromagnetic wave absorption performance, also has phase-change heat absorption and cooling functions, is small in matching thickness and simple and convenient in preparation method, and is suitable for the fields of 5G communication, consumer electronics, national defense and military industry and the like.

The invention provides an intrinsic magnetic MXene material and a preparation method and application thereof, the preparation method comprises the following steps: S1, mixing an aqueous solution of MXene with an alkaline reagent, and carrying out ultrasonic dispersion to obtain a mixed dispersion liquid; freezing the mixed dispersion liquid into a solid by liquid nitrogen; the alkaline reagent is potassium hydroxide or sodium hydroxide; s2, the obtained solid is subjected to freeze drying, and the Archimedes screw type MXene aerogel is obtained; s3, the Archimedes spiral type MXene aerogel is subjected to heat treatment under the protection of inert gas, and the intrinsic magnetic MXene material is obtained. The invention designs and develops a single-component pure MXene electromagnetic wave absorbing material on the premise of not introducing magnetic nanoparticles.

The invention relates to the technical field of wave absorbing materials, and to a preparation method of a flaky carbonyl iron / molybdenum disulfide composite wave absorbing material and corresponding materials, comprising: adding sodium dodecylbenzene sulfonate, sodium molybdate, and thiourea to an ethanol solution according to a ratio and stirring to obtain a precursor solution; placing the precursor solution in a reactor for hydrothermal reaction to obtain a hydrothermal reaction solution, centrifugally washing the hydrothermal reaction solution to obtain a hydrothermal reaction product, vacuum drying the obtained hydrothermal reaction product to obtain a molybdenum disulfide nanomaterial; mixing the molybdenum disulfide nanomaterial with flaky carbonyl iron according to a ratio and grinding to obtain a mixed powder, bonding the mixed powder to obtain a flaky carbonyl iron / molybdenum disulfide composite wave absorbing material. The preparation method of the flaky carbonyl iron / molybdenum disulfide composite wave absorbing material and the corresponding materials of the invention can prepare a wave absorbing material with excellent electromagnetic wave absorption performance and can meet the absorption requirements of different frequency bands.

The invention relates to a preparation method of a lightweight reduced graphene oxide-silicon dioxide electromagnetic wave absorbing material. The invention belongs to the technical field of electromagnetic wave absorbing materials. The invention solves the problems that the impedance of the existing reduced graphene oxide is mismatched, the density of the modified reduced graphene oxide composite wave-absorbing material is increased and the preparation method is complicated. The method comprises the following steps: performing chemical crosslinking on graphene oxide, silicon dioxide and a silane coupling agent to obtain a precursor; and drying and sintering the precursor. The material prepared in the invention has good impedance matching and abundant interface polarization and relaxation effects, can effectively reduce the reflection loss value of electromagnetic waves and increase the effective absorption bandwidth of the electromagnetic waves, and has excellent electromagnetic wave absorption performance. When the thickness of the material is only 1.5 mm, the RL of the material can reach-54.08 dB, and when the thickness of the material is 1.7 mm, the effective absorption bandwidth of the material can reach 5.12 GHz. In addition, the density of the material is only 0.083 g / cm < 3 >, the process is simple, and stable batch production can be realized.

The invention provides a BN fiber-coated PANI nano composite wave-absorbing material and a preparation method thereof, and relates to the field of wave-absorbing materials. The preparation method of the BN fiber-coated PANI nano composite wave-absorbing material comprises the following steps: pre-contact, reaction coating and post-treatment. According to the BN fiber-coated PANI nano composite wave-absorbing material and the preparation method thereof, the defects that an existing microwave absorbing material formed by combining fibers and polyaniline is poor in thermal stability, the composite effect of the fibers and polyaniline is affected, and the microwave absorbing performance and the mechanical performance of the microwave absorbing material are affected can be overcome, meanwhile, uniform distribution of polyaniline on the outer surfaces of the boron nitride fibers is achieved, and the wave-absorbing performance of the BN fiber-coated PANI nano composite wave-absorbing material is improved. Polyaniline and boron nitride fibers are effectively and firmly combined; the flame retardant property, the corrosion resistance and the conductivity of the microwave absorbing material are further improved.

The invention provides Yb2Si2O7-BaSrAlSiO / TiO2nws composite ceramic as well as a preparation method and application of the Yb2Si2O7-BaSrAlSiO / TiO2nws composite ceramic, and solves the problems of the existing microwave absorption ceramic. The Yb2Si2O7-BaSrAlSiO / TiO2nws composite ceramic is prepared by adopting a cold pressing method according to a research and development path of introducing TiO2nws and BaSrAlSiO on the basis of Yb2Si2O7 ceramic, and the ternary ceramic, namely the Yb2Si2O7-BaSrAlSiO / TiO2nws composite ceramic, which is adjustable in dielectric constant and electromagnetic wave absorption characteristic and has different energy gaps and structural properties can be realized by changing the mass ratio of raw materials.

The invention relates to the technical field of high-performance composite materials, and provides a frequency band magnetic control adjustable one-dimensional nanotube composite wave-absorbing material and a preparation method thereof.The material is composed of a one-dimensional tubular ferroferric oxide matrix and manganous-manganic oxide wrapping the outer side of the matrix, and directional arrangement is conducted through magnetic control rotation. The preparation method comprises the following steps: preparing an iron oxyhydroxide precursor through a hydrothermal synthesis method; the preparation method comprises the following steps: reducing an iron oxyhydroxide precursor by a liquid-phase pyrolysis method, and coating a manganous-manganic oxide shell layer in situ at the same time, so as to obtain a nanotube ferroferric oxide / manganous-manganic oxide composite material; and carrying out orientation arrangement on the nanotube-shaped ferroferric oxide / manganous-manganic oxide composite material through magnetic field control. According to the preparation method and the structural design, the yield, the uniformity, the magnetic performance, the electromagnetic wave absorption efficiency, the multi-band electromagnetic loss enhancement and the like of the material are remarkably improved.

The invention relates to a preparation method of SiC concrete with an electromagnetic wave absorption function and concrete.The method comprises the steps that 1, fine aggregate, Portland cement, fly ash and coarse aggregate are evenly mixed to obtain powder, the fine aggregate comprises modified SiC and sand, the modified SiC accounts for 15% or less of the total mass of the concrete, and the sand accounts for 15% or less of the total mass of the concrete; wherein the modified SiC is obtained by modifying a silane coupling agent; step 2, adding a water reducing agent into water, dissolving to obtain a water reducing agent aqueous solution, and uniformly mixing the powder with the water reducing agent aqueous solution in a stirring state to obtain a wave-absorbing concrete stirring material; and step 3, pouring the wave-absorbing concrete mixed material obtained in the step 2 into a mold for pouring, vibrating and molding, and maintaining for 28 days to obtain the SiC wave-absorbing concrete. The SiC concrete with the electromagnetic wave absorption function has good electromagnetic wave absorption performance, wave absorption strength and effective frequency band width; the strength of the concrete is guaranteed, and meanwhile, the mechanical property of the concrete can be improved.

A preparation method of a magnetic metal nanoparticle-loaded nitrogen-doped wood carbon aerogel wave-absorbing material comprises the following steps: step 1, delignification is performed on cut natural wood, and then freeze drying is performed to obtain delignified wood aerogel; 2, the delignification wood aerogel and a metal adenine solution are subjected to a reaction in a reaction kettle, then freeze drying is conducted, and wood aerogel loaded with a metal adenine complex is obtained; 3, the wood aerogel loaded with the metal adenine complex is subjected to high-temperature carbonization treatment in inert gas, and the nitrogen-doped wood carbon aerogel wave-absorbing material loaded with the magnetic metal nanoparticles is obtained. According to the method, natural wood with a directional multilevel pore channel structure is used as a raw material, and a metal-organic complex grows in situ in a pore channel of the wood through solvothermal reaction. The invention aims to realize uniform dispersion and loading of magnetic nanoparticles in a wood carbon-based material so as to solve the problems of non-uniform structure, complex processing procedures and the like in the preparation process of the wave-absorbing material.

The invention relates to the field of inorganic nano composite materials, and provides a preparation method of a nitrogen-doped carbon nanotube wave-absorbing material filled with Fe7S8-FeS2. The method aims at solving the technical problems that the dielectric regulation and control mechanism of a transition metal sulfide wave-absorbing material is not clear, the electromagnetic wave absorption frequency band is narrow, and the absorption strength is low. According to the main scheme, the method comprises the following steps: dissolving dicyandiamide and ferric chloride in deionized water, and heating and drying to obtain red powder; annealing the powder to obtain Fe / nitrogen-doped carbon nanotube black powder; after mixing with sulfur powder, annealing again to obtain Fe7S8 / nitrogen-doped carbon nanotube black powder; and finally, mixing and annealing with sulfur powder to obtain the Fe7S8 / FeS2 filled nitrogen-doped carbon nanotube wave-absorbing material. The material shows excellent absorption strength and absorption bandwidth under the condition of low thickness (1.6 mm), the maximum reflection loss is-36.83 dB, and the effective absorption bandwidth is 5.14 GHz (11.9-17.04 GHz). The invention also provides application of the material, namely the material is used as a wave-absorbing material, and is mixed with paraffin or epoxy resin and then coated on the surface of a protected object.

The invention relates to the technical field of functional resin-based composite materials, in particular to a chopped carbon fiber felt-based impact-resistant and wave-absorbing dual-function-integrated resin-based composite metamaterial and a simplified preparation process thereof.The chopped carbon fiber felt-based impact-resistant and wave-absorbing dual-function-integrated resin-based composite metamaterial comprises an upper dielectric layer, an array structure layer, a lower dielectric layer and a bottom reflecting layer which are sequentially stacked from top to bottom; the array structure layer is of a central symmetry structure and is formed by periodically arranging m * n carbon fiber felt structure units; the carbon fiber felt structural unit is a square annular patch, the outer ring width L1 of the square annular patch is 23-26 mm, the inner ring width L2 of the square annular patch is 10-15 mm, and the periodic side length P of the carbon fiber felt structural unit is 30 mm. Due to the miniaturization design of the structural units, the oblique incidence responses of the metamaterial in a transverse electric polarization mode and a transverse magnetic polarization mode can reach 45 degrees and 60 degrees respectively; and when the incident angle of the transverse magnetic wave is up to 60 degrees, 80% of electromagnetic wave absorptivity can still be maintained.

The invention provides a ternary composite nanofiber capable of being used for marine metal corrosion prevention and electromagnetic wave absorption and a preparation method and application of the ternary composite nanofiber. The preparation method of the ternary composite nanofiber comprises the following steps: (1) preparation of a precursor solution: dispersing a copper salt and a cobalt compound in a first solvent, stirring until the copper salt and the cobalt compound are fully dissolved, adding a polymer, and uniformly mixing to obtain the precursor solution; (2) preparation of a nanofiber membrane: performing electrostatic spinning on the precursor solution to obtain the nanofiber membrane loaded with copper and cobalt metal ions; and (3) carbonization: drying the nanofiber membrane, and performing high-temperature treatment after drying to obtain the ternary composite nanofiber capable of being used for marine metal corrosion prevention and electromagnetic wave absorption. The preparation method of the ternary composite nanofiber is simple and low in cost, and the prepared ternary composite nanofiber has a huge application prospect when being used for electromagnetic wave shielding in corrosion environments such as ocean.

The invention relates to a high-entropy oxide wave-absorbing ceramic powder material as well as a preparation method and application thereof, belongs to the technical field of electromagnetic wave absorbing materials, and solves the problems of poor high-temperature resistance and oxidation resistance and low absorption efficiency on low-frequency wave bands of an existing electromagnetic wave absorbing material. The high-entropy oxide ceramic material has a perovskite structure, the molecular structure is ABO3, A comprises La and Sr, and B is at least five elements of Cr, Ni, Mn, Fe, Co, Zr, Hf and Ti. According to the invention, the high-entropy oxide is combined with the perovskite structure, the electromagnetic function of the high-entropy oxide ceramic material is accurately regulated and controlled, and effective absorption of low-frequency electromagnetic waves is realized; the material has oxidation resistance and thermal stability under a high-temperature condition, and excellent electromagnetic function strength of the material at a high temperature is maintained. According to the high-entropy oxide ceramic powder material, the range of an electromagnetic wave absorbing material is widened, the environmental adaptability is improved, and higher requirements of development of a communication technology on the electromagnetic wave absorbing material are met.

The invention discloses a preparation method and application of a MgFe2O4 / coal gasification fine slag composite material, and the preparation method comprises the following steps: dissolving a divalent magnesium source and a trivalent iron source which can be dissolved in ethylene glycol according to a molar ratio of 1: 2 in ethylene glycol to obtain a solution A; taking 50-70 mL of the solution A, then adding 0.4-0.6 g of hexadecyl trimethyl ammonium bromide and 0.5-0.7 g of coal gasification fine slag, and carrying out uniform ultrasonic dispersion to obtain a solution B; and gradually dropwise adding alkali liquor into the solution B, continuously stirring in the process of dropwise adding the alkali liquor, stopping stirring when the pH value of the solution B reaches 10.5-11.5, then putting the obtained mixture into a 100mL high-pressure reaction kettle, heating to 160-190 DEG C in a closed manner, keeping the temperature for 10-15 hours, then cooling, washing and drying the obtained precipitate, thereby obtaining the MgFe2O4 / coal gasification fine slag composite material. According to the invention, the defects in the prior art are overcome, the resource utilization of the waste coal gasification fine slag is realized, and the preparation cost of the electromagnetic wave absorbing material is effectively reduced.

The invention discloses a preparation method and application of a shape-controllable high-performance carbon wave-absorbing material. The invention belongs to the technical field of wave-absorbing materials. The invention aims to solve the technical problems that the impedance matching characteristic and the attenuation characteristic of the existing pure carbon absorbent are unbalanced and the effective absorption frequency band is limited. The method comprises the following steps: firstly, under a heating condition, respectively dissolving melamine and cyanuric acid in deionized water or an ethanol water solution, then dropwise adding a melamine solution into a cyanuric acid solution, and heating and stirring for reaction to obtain a hydrogen bond organic framework; and adding the hydrogen bond organic framework into an absolute ethyl alcohol solution of phenolic resin, stirring for reaction, and calcining to obtain the carbon wave-absorbing material. The method is simple in process and low in cost. The obtained wave-absorbing material has excellent electromagnetic wave absorption performance, and almost covers all X and Ku wave bands. And the application requirements of thinness, lightness, width and strength are met.

The invention relates to a MnCo-based metal oxide electromagnetic wave absorbing material as well as a preparation method and application thereof. The composition of the MnCo-based metal oxide electromagnetic wave absorbing material is Mn2. 05Co0. 91 O4, the preparation method comprises the following steps: preparing raw materials from a cobalt source, a manganese source, urea and ammonium persulfate according to a molar ratio, and dissolving the raw materials in deionized water to obtain a metal salt solution; carrying out hydrothermal reaction; centrifugally washing, drying and grinding; and calcining, and directly quenching after calcining to finally obtain the MnCo-based metal oxide electromagnetic wave absorbing material. The MnCo-based metal oxide electromagnetic wave absorbing material disclosed by the invention has excellent wave absorbing performance: by changing a quenching medium, customizing the lattice strain of the MnCo-based metal oxide, inducing the generation of unpaired electrons and optimizing the dielectric property of the MnCo-based metal oxide electromagnetic wave absorbing material, the wave absorbing performance of the MnCo-based metal oxide electromagnetic wave absorbing material is finally improved; the preparation process is simple and easy to implement, the metal oxide material with excellent and stable wave-absorbing performance is prepared through simple hydrothermal reaction, calcination and quenching processes, and the metal oxide material has great application prospects.

The invention discloses an organic matter-based wave-absorbing composite material filled with a two-dimensional ferrite film and a preparation method of the organic matter-based wave-absorbing composite material, and the method comprises the following steps: preparing a ferrite / Sr3Al2O6 / SrTiO3 heterostructure filled with the two-dimensional ferrite film on an SrTiO3 single crystal substrate with the crystal orientation of (100) by using a ferrite target material and an Sr3Al2O6 target material and adopting a pulse laser deposition technology; stripping a ferrite film in the heterostructure by adopting a water dissolving method to prepare a ferrite / PDMS heterostructure; the preparation method comprises the following steps: spin-coating a mixed solution of an organic film on a monocrystalline silicon (Si) substrate by adopting a spin-coating method to prepare an organic film / Si heterostructure; the ferrite / PDMS heterostructure and the organic matter film / Si heterostructure are subjected to hot pressing through a hot pressing method, and the organic matter-based wave-absorbing composite material filled with the two-dimensional ferrite film is prepared. The preparation process of the organic matter-based wave-absorbing composite material is simple, and the prepared organic matter-based wave-absorbing composite material avoids the phenomena that ferrite powder particles are agglomerated and electromagnetic waves bypass the ferrite particles.

The invention provides a FeTe1-xOx electromagnetic wave-absorbing material as well as a preparation method and application thereof. The method comprises the following steps: S1, placing a quartz boat containing Te nano powder in an upstream temperature zone of a tubular furnace; s2, placing a certain amount of FeCl2 powder in another quartz boat, and placing the quartz boat in a central temperature zone of a tubular furnace; s3, respectively heating the temperature zones in which the quartz boat in the S1 and the other quartz boat in the S2 to reaction temperatures, keeping the temperature until the FeCl2 powder and the Te powder fully react, and preparing two-dimensional FeTe nanosheets in batches by utilizing a chemical vapor deposition technology; and S4, placing the two-dimensional FeTe nanosheets obtained in S3 in an oxygen plasma treatment instrument, and preparing the oxygen-doped two-dimensional FeTe < 1-x > Ox electromagnetic wave-absorbing material with tellurium vacancies with different concentrations by regulating and controlling performance parameters of the plasma treatment instrument. The product provided by the invention can activate basal plane inert sites of FeTe, and effectively optimizes dielectric relaxation loss, thereby realizing improvement of electromagnetic wave-absorbing performance.

The invention discloses a method for synergistically optimizing carbon nano spiral aerogel through a carbon layer / zinc oxide and an obtained product and application of the carbon nano spiral aerogel. Firstly, zinc oxide is deposited on the surface of CNC aerogel through an atomic layer deposition method, and ZnO-coated CNC aerogel is obtained; then, the ZnO (at) CNC aerogel is soaked in a dimethyl imidazole methanol solution, and the ZIF-8 / ZnO (at) CNC aerogel is obtained. Finally, the ZIF-8 / ZnO (at) CNC aerogel is roasted in an inert environment, and the C / ZnO (at) CNC aerogel composite material is generated. The C / ZnO-coated CNC aerogel composite material is prepared through atomic layer deposition, an impregnation method and a chemical vapor deposition method, the process is simple, the amount of ZnO can be accurately controlled, and the composite material has good conductivity, electromagnetic wave absorption performance and photothermal conversion performance and has wide application value in the fields of photothermal conversion, electromagnetic wave absorption and the like.

The invention provides a magnetic control adjustable heat phase change material for electromagnetic wave absorption and a preparation method thereof, and the magnetic control adjustable heat phase change material comprises the following raw materials in parts by mass: a thermoplastic paraffin matrix, and magnetic composite particles and expanded graphite which are distributed in the thermoplastic paraffin matrix, the magnetic composite particles are prepared by depositing nano Fe on the surface of flaky carbonyl iron powder through an oxidation-reduction method. The composite material is cast on a substrate with a planar coil, and different magnetic field modes are formed by adjusting the current direction of the planar coil when the material is heated and melted so as to change the chained arrangement mode of the magnetic particles, so that the wave-absorbing performance is optimized. By changing the heating condition and the magnetic field direction, the microstructure of the material is subjected to phase change driven reconstruction, and the material is endowed with multi-band wave-absorbing capacity and dynamic response characteristic. The invention combines the dual characteristics of thermal phase change and magnetic response, and is especially suitable for the field of intelligent stealth devices and electromagnetic wave protection requiring variable wave absorbing performance.

The invention discloses a preparation method of a carbon cage-in-cage / carbon coated nickel composite material with infrared stealth performance, an obtained product and application. The preparation method comprises the following steps: preparing nickel microspheres; roasting the nickel microspheres and urea in an inert atmosphere to obtain an NC / Ni composite material; and the NC / Ni composite material is placed in diluted hydrochloric acid for acid etching, and the cage-in-cage / carbon-coated nickel composite material is obtained. The obtained composite material is of a carbon-coated nickel modified carbon micron cage-coated nano cage structure, the process is simple, the cage-in-cage structure of the carbon cage can be accurately controlled, the defect that nickel elementary substances are easy to agglomerate is effectively overcome, and the composite material has good conductivity, electromagnetic wave absorption performance and low infrared emissivity and can be applied to the field of electrochemistry. Wide application values are realized in the fields of infrared stealth, electromagnetic wave absorption and the like.

The application discloses a kind of natural rubber filling nickel-aluminum bimetallic hydroxide multi-walled carbon nanotube composite material for electronic component packaging, belong to packaging material technical field, the composite material includes natural rubber matrix and dispersed nickel-aluminum bimetallic hydroxide / multi-walled carbon nanotube hybrid filler, the hybrid filler is made of multi-walled carbon nanotube and nickel-aluminum layered double hydroxide grown in its surface in situ.Its preparation method is: multi-walled carbon nanotube, nickel source, aluminum source, urea and ammonium fluoride are dissolved in water and prepared hybrid filler by hydrothermal reaction;Then it is mixed with natural latex, vulcanization aid dispersion, freeze-drying, vulcanization is obtained.The application improves the dispersibility of filler by constructing LDH / MWCNT hybrid structure, uses phonon transmission optimization, synergism of loss and impedance, combustion inhibition and the friction and reinforcing mechanism of hybrid filler and natural rubber molecular chain, so that the thermal conductivity, electromagnetic wave absorption capacity, flame retardancy, mechanics and damping performance of the composite material are simultaneously improved, suitable for electronic component packaging field.

A core-shell structure material with a wrinkled surface, and a preparation method and application thereof, wherein the core-shell structure material with a wrinkled surface is formed by coating a foamed sphere core with a three-dimensional carbon wrinkled shell layer; the mass ratio of the three-dimensional carbon wrinkled shell layer to the foamed sphere core is 1:3-10. The preparation method comprises: (1) soaking the dried foamed sphere in a carbon source aqueous solution; (2) standing and drying, heating and shrinking to a stable state, and obtaining a core-shell structure material with a wrinkled surface. The core-shell structure material with a wrinkled surface, or a core-shell structure composite material with a densely packed surface wrinkles obtained by compounding in a frame with a periodic structure, is applied to the fields of electromagnetic wave absorption, catalysis, adsorption and sensing. In the core-shell structure material of the present invention, the three-dimensional carbon wrinkled shell layer is firmly combined with the foamed sphere core, has a large size of millimeters, a controllable morphology, diverse properties, a large specific surface area, and excellent electromagnetic wave absorption performance. The method of the present invention is environmentally friendly, green, efficient, convenient, low-cost, and suitable for industrial production.

The invention belongs to the technical field of inorganic nonmetallic materials, and particularly relates to a preparation method and application of a cubic phase TiC nanosheet. The preparation method comprises the following steps: firstly, taking multi-layer Mxene (Ti3C2Tx) as a raw material, taking tetramethylammonium hydroxide as an intercalation agent, and thinning intercalation to obtain less-layer Ti3C2Tx; then 3-aminophenol is used for carrying out coating treatment on the Ti3C2Tx nanosheets, and the content of C on the surfaces of the few-layer Ti3C2Tx nanosheets is increased; and finally, taking the coated few-layer Ti3C2Tx as a template, and carrying out high-temperature calcination treatment in an argon atmosphere to obtain the cubic-phase TiC nanosheet. The cubic phase titanium carbide nanosheet prepared by the method has the advantages of controllable sheet shape, simple operation and mass production, and can be used in the field of electromagnetic wave absorption.

This invention belongs to the field of electromagnetic wave absorbing materials technology, and specifically discloses a hollow spherical Ti3C2T x @Molybdenum disulfide@cobalt / carbon composite materials, their preparation methods, and applications. The preparation method includes the following steps: reacting formaldehyde with melamine to prepare melamine-formaldehyde resin particles, ultrasonically dispersing them in water, and then adding Ti3C2T. x Suspension, stirred, melamine-formaldehyde resin particles with Ti3C2T x Self-assembly yields the core-shell material Ti3C2T x @MF; Ti3C2T x @MF, molybdenum source, and sulfur source are dispersed in water in a certain proportion and subjected to a hydrothermal reaction. The hydrothermal reaction product is washed and dried to obtain hollow spherical Ti3C2T x @Molybdenum disulfide composite material HTM; A dimethylimidazole alcohol solution is slowly added to a mixed alcohol solution of HTM and a cobalt source, stirred for a set time, and then allowed to stand for a set time to obtain HTM@ZIF67; HTM@ZIF67 is then pyrolyzed in an inert atmosphere to obtain hollow spherical Ti3C2T. x @Molybdenum disulfide@cobalt / carbon composite material. This material combination can effectively promote the attenuation of electromagnetic waves and reduce the material's filler content.

The invention relates to a ferric oxide / porous carbon heterogeneous composite wave-absorbing material as well as a preparation method and application thereof. The ferric oxide provides high magnetic conductivity and saturation magnetization intensity, the porous carbon formed by carbonizing the covalent organic framework with a regular structure can provide high conductive loss, a heterogeneous interface formed by the composite material provides abundant interface polarization, different element compositions provide dipole polarization, and the composite material has high magnetic conductivity and high saturation magnetization intensity. And good electromagnetic coupling enables the antenna to have excellent impedance matching and electromagnetic loss capabilities.