137 results about "Interfacial polarization" patented technology

The invention relates to the field of super-hydrophobic materials, in particular to a basalt fiber composite material as well as a preparation method and application thereof. According to the composite fabric material provided by the invention, a multistage micro-nano rough surface of the MoS2 nanoflowers and the silver nanoparticles is constructed on the fiber substrate, so that not only is super-hydrophobic self-cleaning realized, but also the anti-icing performance is relatively high, and particularly, rapid heating is realized by combining broadband absorption of the MoS2 nanoflowers and a local surface plasma resonance effect of the silver nanoparticles; and meanwhile, the silver nanoparticles accelerate heat conduction, so that excellent ice melting capability is obtained. The high conductivity of the silver nanoparticles constructs a conductive path, and the layered structure of MoS2 triggers interface polarization, so that the electromagnetic shielding effectiveness of the X wave band is improved. The dual antibacterial mechanism of the MoS2 nanoflowers and the silver nanoparticles also realizes broad-spectrum efficient antibiosis, the preparation method is green and environment-friendly, the cost is low, and the requirements of complex scenes such as wearable electronic equipment, medical protection, polar region protection and national defense can be met.

The invention relates to the technical field of material detection, and discloses an identification analysis and method for recessive degradation of a flexible conductive composite material, and the system comprises a perturbation excitation module, a response collection module, a time sequence feature extraction module, a micro-response trend consistency analysis module, and a state evaluation and early warning module. Multiple periods of small-signal capacitance excitation are applied to the material, pi-pi stacking slippage and interface polarization behaviors in a conductive network are excited, electrical response data are collected to construct a time sequence feature vector, and the deviation degree of the evolution trend is further calculated. And based on the trend deviation index, performing health state scoring and triggering early warning, thereby realizing early recognition and evaluation of material recessive degradation.

The invention relates to the technical field of wave-absorbing materials, in particular to a preparation method of an MXene-NiO-PPy ternary composite wave-absorbing material. The invention provides a preparation method of an MXene-NiO-PPy ternary composite wave-absorbing material, which comprises the following steps of: etching titanium aluminum carbide powder through a LiF / HCl mixture, and performing ultrasonic stripping to prepare a uniform dispersion of MXene nanosheets; the preparation method comprises the following steps: dispersing MXene nanosheets in a solution of water and absolute ethyl alcohol, and adding a pyrrole monomer and a FeCl3. 6H2O aqueous solution for reaction; after the reaction, washing is performed to obtain a PPy-MXene composite material; the preparation method comprises the following steps: by taking NiCl2. 6H2O as a nickel source and sodium oxalate as a precipitator, preparing NiO nanowires by adopting a hydrothermal method combined with a calcining process; the invention discloses a preparation method of an MXene-NiO-PPy ternary composite wave-absorbing material.According to the method, the MXene-NiO-PPy ternary composite wave-absorbing material with rich heterogeneous interfaces and a porous micro-nano structure is constructed, cooperation of dielectric loss, magnetic loss and interface polarization loss is achieved, and finally the light, efficient and broadband wave-absorbing performance is obtained.

The invention discloses a preparation method of a beaded cobalt-doped Bi25FeO40 / BiFeO3 nanofiber wave-absorbing material, which comprises the following steps: obtaining a precursor by a standing method, and adding the precursor, bismuth nitrate, ferric nitrate and a spinning aid into a mixed solvent compounded by N, N-dimethylformamide and absolute ethyl alcohol to obtain a spinning solution; spinning the spinning solution by adopting an electrostatic spinning technology to obtain a nanofiber membrane; and finally, drying and calcining to obtain the wave-absorbing material. According to the wave-absorbing material, multiple reflection and scattering of electromagnetic waves are increased, the absorption performance of the electromagnetic waves is improved, due to the fact that a heterogeneous interface is generated after two phases are compounded, the interface polarization loss is further increased, when the thickness of the wave-absorbing material is 2.33 mm, the minimum reflection loss reaches-56.01 dB, the effective absorption frequency band width is 6.32 GHz, and the whole Ku wave band is covered.

The invention belongs to the technical field of preparation of wave-absorbing materials, and particularly relates to a cobalt-based nitrogen-doped carbon nano composite material with a hollow cubic structure as well as a preparation method and application thereof. Comprising the following steps: taking ZnCo-ZIF with a nano cubic structure as a core, coating ZnCo-ZIF with polydopamine by adopting a precipitation method to form a precursor with a core-shell structure, and carbonizing the precursor at 800-900 DEG C to obtain the cobalt-based nitrogen-doped carbon nano composite material with the hollow cubic structure. According to the invention, the dielectric loss capability can be enhanced by using the conductivity and interface polarization effect of the coated carbon layer, and the Co particles introduce strong magnetic loss; meanwhile, due to interface polarization caused by abundant heterogeneous interfaces existing between the Co particles and the coating carbon layer, between the magnetic particles and the carbon nanotubes and between the carbon matrix and the carbon nanotubes in the composite material, the impedance matching characteristic can be improved, and high reflection loss and wide effective absorption bandwidth can be achieved under the low matching thickness.

The invention belongs to the technical field of waste lithium battery recovery, and particularly relates to a method for selectively extracting lithium from a waste lithium iron phosphate positive electrode material based on interface polarization activation-complexing impurity inhibition, which comprises the following steps: 1) adding the waste lithium iron phosphate positive electrode material, an oxidizing agent and an activating agent into a solvent, stirring and leaching, and carrying out solid-liquid separation after leaching to obtain a leaching solution; and (2) adding inorganic salt into the leachate, enabling the inorganic salt and the activating agent in the step (S1) to generate precipitate, and carrying out solid-liquid separation to obtain a lithium-rich solution. Through the synergistic effect of the activating agent and the oxidizing agent, the lithium is deintercalated while the main body of the waste lithium iron phosphate positive electrode material is not dissolved basically, the leaching rate of the lithium can reach 99% or above, and the content of iron and phosphorus impurities in the lithium-rich solution is low. The method has the advantages of being high in lithium leaching rate, good in lithium selectivity, wide in leaching temperature application range, short in technological process, few in generated waste and low in cost, and particularly, the method also has the excellent selective lithium leaching effect at the low temperature.

The invention discloses an electromagnetic wave absorbing material CoFe2O4 / ZnO-RGO with a ternary heterostructure as well as a preparation method and application of the electromagnetic wave absorbing material CoFe2O4 / ZnO-RGO, and belongs to the technical field of electromagnetic wave absorption. According to the material, a novel heterostructure with a multi-scale interface and a three-dimensional conductive network is constructed by compounding magnetic loss type CoFe2O4, dielectric loss type ZnO nanorods and resistance loss type RGO. Wherein the ZnO nanorod not only serves as a dielectric loss body, but also effectively enhances the structural anisotropy and the interface polarization effect of the material, and cooperates with the magnetic loss of CoFe2O4 and the resistance loss of RGO to jointly optimize impedance matching and improve the electromagnetic attenuation capability, so that the material shows excellent wave-absorbing performance under various thickness and even ultrathin conditions. The material source is wide, the cost is low, the preparation process is green, simple and convenient, the material is suitable for large-scale production, and an effective material solution is provided for electromagnetic wave absorption application in the national defense and civil fields.

The invention relates to the technical field of power system state monitoring, and discloses an insulator defect detection method and device and a storage medium, and the method comprises the steps: collecting the leakage current of an insulator, and constructing a polarity conduction screening model through power frequency phase information, so as to generate a composite current sequence which highlights the polarization attribute of an interface; analyzing the nonlinear degree of the attenuation rate of the sequence drifting along with evolution time in a multi-stage diffusion evolution time domain, and generating an interface electrochemical mass transfer composite index; utilizing the index to invert and construct an interface polarization background reference and stripping the interface polarization background reference from the composite current sequence so as to extract an abnormal discharge pulse residual error; and finally, quantizing the pulse form distortion degree of the residual error, and performing suppression normalization operation on the distortion degree by using the index to output a judgment result. According to the invention, the interference of the interface mass transfer process is effectively eliminated, and the specific detection of the pollution flashover hidden danger is realized.

The invention discloses a Fe3C (at) C assembled nano wave-absorbing structure and a preparation method thereof, and the preparation method comprises the following steps: synthesizing Fe2O3 (at) C spheres through a hydrothermal method, carrying out carbon removal treatment on the Fe2O3 (at) C spheres by adopting an air oxidation method to obtain a Fe2O3 hollow sphere precursor, and finally carrying out chemical vapor deposition (CVD) reaction on the obtained Fe2O3 hollow sphere precursor to convert a Fe2O3 phase in the Fe2O3 hollow sphere precursor into a Fe3C phase to form Fe3C hollow spheres, thereby obtaining the Fe3C assembled nano wave-absorbing structure. And growing a C nano-particle array on the surface of the Fe3C hollow sphere in situ so as to obtain the Fe3C-C assembled nano wave-absorbing structure. The problems that an existing magnetic wave-absorbing material is large in density, poor in impedance matching, low in electromagnetic wave loss efficiency and the like are solved. According to the prepared nano wave-absorbing structure, coupling of dielectric loss and magnetic loss and optimization of impedance matching are easily achieved, the multiple scattering effect of electromagnetic waves is greatly enhanced through the C nano-particle array structure and the hollow structure on the surface of the nano wave-absorbing structure, enhancement of the interface polarization relaxation loss effect is promoted through a large number of Fe3C-C heterogeneous interfaces, and the wave-absorbing performance is improved.

The application discloses a kind of high-entropy dual-phase sulfide and its preparation method and application, belong to electromagnetic wave absorbing material field.The application wants to solve how to enhance the weak interface polarization effect of high-entropy sulfide in electromagnetic attenuation problem.The application introduces Cu and Al metal elements into multi-metal sulfide by solvothermal and annealing method, and synthesizes a kind of six-component high-entropy sulfide wave-absorbing material (6-HES) with dual-phase structure, wherein all metal elements are uniformly distributed in M9S8 and MS (M represents metal element) two phases with crystal lattice defects.The high-entropy dual-phase sulfide prepared by the method has heterogeneous interface structure and rich vacancy defects, which not only can improve its conductance loss, but also can enhance defect-induced polarization and interface loss.The application taps the potential of multi-metal sulfide in the field of electromagnetic attenuation.

The invention belongs to the field of wave-absorbing materials, and particularly relates to three-dimensional oriented porous aerogel loaded with yttrium-cobalt nanoparticles as well as a preparation method and application of the three-dimensional oriented porous aerogel. According to the invention, electromagnetic waves are forced to repeatedly refract and scatter through the three-dimensional honeycomb-shaped directional pore channels to have a synergistic effect with multiple heterogeneous interfaces (carbon / Co, carbon / Y2O3 and Co / Y2O3), so that the material synchronously enhances interface polarization, dipole polarization and magnetic-dielectric loss, and efficient attenuation of the electromagnetic waves is realized; by forming an intermediate ZIF-67, highly uniform dispersion of cobalt on a molecular scale is realized, and a subsequent in-situ carbonization process is combined, so that highly dispersed and tightly embedded Co nanoparticles are successfully formed in a chitosan derived carbon skeleton, the interface bonding strength is remarkably improved, and agglomeration is inhibited; according to the process, biomass chitosan is used as a carbon source, and the process has the advantages of low filling, high performance and industrial compatibility. The aerogel-based wave-absorbing material disclosed by the invention has important application value in the fields of communication, aerospace and military protection.

The application provides a hetero-composite wave-absorbing material based on attapulgite, a preparation method and application thereof. The wave-absorbing material is prepared by acid activation and high-frequency ultrasonic stirring to disperse attapulgite in a deionized water system to form an attapulgite emulsion, and the well-dispersed attapulgite fibers are uniformly coated with a carbon layer on the surface through hydrothermal stirring and high-temperature carbonization; then, a flower-like NiCo2O4 is grown in situ on the carbon-coated attapulgite to construct a hetero-interface, the carbon-coated attapulgite is used as a dielectric loss material, the flower-like NiCo2O4 is used as a magnetic loss material, through hetero-structure design, the carbon layer can inhibit the skin effect caused by the cross-linked flower-like NiCo2O4, so as to amplify the magnetic response behavior of the NiCo2O4; the hetero-interface formed between the two can significantly enhance the interface polarization, realize impedance matching, significantly improve the microwave absorption performance, and overcome the defects of impedance mismatch and structure design existing in the prior art magnetic-dielectric synergistic wave-absorbing material.

The invention provides a micron rod-shaped Fe-Si-Al-based composite electromagnetic wave-absorbing material and a preparation method thereof, spherical FeSiAl alloy powder is subjected to ball milling to obtain micron rod-shaped powder, and the surface of the FeSiAl alloy powder is coated with TiO2 by utilizing hydrolysis reaction of tetrabutyl titanate, so that a FeSiAl-coated TiO2 core-shell composite electromagnetic wave-absorbing material is prepared; the FeSiAl-coated TiO2 core-shell composite electromagnetic wave-absorbing material is annealed in an argon or hydrogen-argon mixed gas atmosphere, the micron rod-shaped iron-silicon-aluminum-based composite electromagnetic wave-absorbing material is prepared, the shape anisotropy and the magnetic conductivity of FeSiAl are effectively improved, the oxygen vacancy concentration of TiO2 is regulated and controlled through annealing in a hydrogen-argon mixed gas reducing atmosphere, the polarization relaxation of dipoles is enhanced, and the electromagnetic wave-absorbing effect is improved. The core-shell structure enhances interface polarization, improves magnetic loss and dielectric loss, and effectively enhances the wave-absorbing bandwidth and reflection loss of the wave-absorbing material.

The invention discloses an iron-based nanoparticle and titanium dioxide magnetoelectric core-shell structure composite wave-absorbing material and a preparation method thereof, and belongs to the technical field of microwave absorbing materials. According to the preparation method, ferroferric oxide coated with titanium dioxide is taken as a precursor, and based on a confinement hydrogen reduction process, the relative content of a titanium dioxide shell layer and an iron and iron oxide composite core is changed by adjusting the dosage of tetrabutyl titanate, so that the construction and regulation of the magnetoelectric core-shell structure are realized. In the obtained composite wave-absorbing material, iron in the magnetic core can provide strong magnetic loss, iron oxide can improve impedance matching characteristics and introduce dielectric loss, and the titanium dioxide shell layer can enhance interface polarization and optimize impedance matching, so that the composite wave-absorbing material shows excellent low-thickness and broadband wave-absorbing characteristics. Meanwhile, the preparation process disclosed by the invention does not need large complex equipment, does not involve the use of highly toxic compounds, and has a relatively high popularization value.

The invention relates to the technical field of batteries, in particular to a positive plate and a preparation method thereof, a battery and electric equipment. The positive plate comprises a positive current collector and a positive active material layer arranged on one side of the positive current collector, the positive active material layer comprises a first active material layer and a second active material layer which are arranged in a stacked mode, the first active material layer is located between the second active material layer and the positive current collector, the first active material layer comprises LiMnx1Fey1PO4 and LiNia1Cob1Mc1O2, x1 + y1 = 1, a1 + b1 + c1 = 1, and the second active material layer is located between the first active material layer and the positive current collector. M comprises at least one of Mn, Al, Zr and Ti; the second active material layer comprises LiMnx2Fey2PO4 and LiNia2Cob2Mc2O2, x < 2 > + y < 2 > = 1, a < 2 > + b < 2 > + c < 2 > = 1, and M'comprises at least one of Mn, Al, Zr and Ti; the ratio of the mass content of Fe to the mass content of Co in the first active material layer is different from the ratio of the mass content of Fe to the mass content of Co in the second active material layer. According to the positive plate, micro-interface polarization can be improved, and the risk of local lithium precipitation caused by uneven charge distribution is reduced.

The application provides a method for calculating interface polarization charge and current distribution based on reflection coefficient, and relates to the technical field of computational electromagnetics. The method comprises the following steps: establishing a reflection coefficient-dielectric parameter mapping, directly correlating the reflection characteristics of electromagnetic waves with the intrinsic parameters of the medium through a reflection coefficient formula, and laying a physical foundation for polarization analysis; interface electromagnetic field reconstruction, using boundary conditions and constitutive relations to determine the electric field distribution on both sides of the interface and the corresponding polarization intensity. The distribution rule of the electromagnetic field in the medium is determined, the macroscopic electric field is converted into the spatial description of the polarization intensity, and an intermediate variable is provided for charge and current calculation; polarization dynamic response quantification, through the spatial and temporal derivatives of the polarization intensity, the interface polarization charge density and the polarization current density are derived. The theoretical model is converted into actual physical quantities, and the dynamic response mechanism of charges and currents when electromagnetic waves interact with the medium is revealed.

This invention provides a broadband high-temperature resistant ceramic-based microwave absorbing material and its preparation method, belonging to the technical field of microwave absorbing materials. The microwave absorbing material uses silicon carbide powder with a particle size of 100-500 nm as the matrix material. Silicon carbide is mixed with acetylene black and polycarbosilane solution and ball-milled to prepare ceramic slurries containing different concentrations of acetylene black. The ceramic slurries are then poured into a steel mold and vibrated on a vibration table. The sample surface is then smoothed and dried in a vacuum freeze dryer. The dried green sample is then subjected to high-temperature pyrolysis under vacuum and bonded to obtain a silicon carbide ceramic-based composite material. This invention utilizes a concentration gradient multilayer structure to effectively improve the impedance matching of the material. Simultaneously, by utilizing the multiple reflection and scattering effects of electromagnetic waves between silicon carbide and acetylene black, as well as the interfacial polarization loss between silicon carbide and black, broadband high absorption of electromagnetic waves can be achieved under high-temperature conditions.

The invention discloses a low-voltage polarizable magnetic dielectric microsphere, a preparation method thereof and application of the low-voltage polarizable magnetic dielectric microsphere to adsorption of PFASs, and relates to the technical field of environmental functional materials. The microsphere has a core-shell structure of a conductive magnetic core-dielectric shell, the core is composed of ferroferric oxide and a carbon material, and the shell is a sodium alginate gel layer. The preparation method comprises the following steps: calcining the iron-carbon composite material, mixing a sodium alginate solution, cross-linking calcium lactate / calcium chloride step by step and the like. The microspheres can be subjected to interface polarization under the external 0.2-2 V / cm low-voltage direct-current electric field, a strong local electric field is generated to enhance electrostatic adsorption, meanwhile, the mass transfer and adsorption process of PFASs is synergistically enhanced through electrophoresis and electroosmotic flow effects, the adsorption rate and capacity are remarkably improved, and rapid separation can be achieved through a magnetic field. The material and the method are suitable for efficiently and deeply removing anionic PFASs in wastewater, and have the advantages of low energy consumption, high efficiency, simplicity and convenience in operation and the like.

A method for preparing a MOF-based multiphase composite electromagnetic wave absorbing material is disclosed, which relates to the preparation method and application of electromagnetic wave absorbing materials. The purpose of this invention is to solve the problems of poor attenuation and narrow absorption bandwidth in ABO3-type perovskite electromagnetic wave absorbing materials prepared by existing methods. This invention is based on the metallic Fe in MIL-88A. 3+ Ions were successfully induced to form an oxide perovskite phase in MIL-88A via etching, resulting in a hierarchical hollow nanocomposite material. In this structure, the oxide perovskite, a typical spinel-type p-type semiconductor, is composited with the surrounding elemental Fe phase through an outer graphitized carbon shell. Utilizing the heterojunction effect with metal-semiconductor contacts, an excellent interfacial polarization process is generated, significantly enhancing the dielectric loss performance of the composite material. Simultaneously, by consuming excess Fe metal... 3+ Excellent electromagnetic wave absorption performance was obtained by adjusting the impedance matching of the composite material.

The invention discloses an anti-microwave-radiation and anti-blue-light spectacle lens and a preparation method thereof, and belongs to the technical field of optical lenses, the anti-microwave-radiation and anti-blue-light spectacle lens is structurally divided into three layers, namely an anti-blue-light layer, a water-resistant antifouling layer and an anti-microwave-radiation layer from bottom to top in sequence, through a special synergistic relationship among the three layers, the interface bonding is good, and the anti-microwave-radiation and anti-blue-light spectacle lens is not easy to peel off; in addition, good microwave radiation prevention and blue light prevention effects are achieved, oil contamination can be prevented, adhesion of rainwater can be avoided when the waterproof and anti-glare film is used in rainy days, and the sight is prevented from being influenced; the prepared antifouling layer contains pyridine groups, the pyridine groups and cobalt metal ions of the ZIF-8 / ferric oxide composite fibers in the microwave radiation prevention layer can easily form coordinate bonds, pyridine group doping is formed, the dielectric loss angle tangent of ZIF-8 is low, and the consumption efficiency of microwave electric field energy is limited. The doping coordination of pyridine groups can promote the formation of active sites, enhance dipole polarization and interface polarization, and improve the microwave radiation resistance of the microwave radiation resistance layer.

This invention belongs to the field of microwave absorbing materials technology, specifically relating to a composite carbon nanofiber microwave absorbing material, its preparation method, and its applications. The composite carbon nanofiber microwave absorbing material is obtained by electrospinning and heat treatment using a polynuclear pentameric acid metal complex as a precursor and polyacrylonitrile as a carbon source. The polynuclear pentameric acid metal complex is any one of trinuclear iron pentameric acid, dinuclear cobalt pentameric acid, and dinuclear nickel pentameric acid. The excellent microwave absorption performance of the composite carbon nanofiber microwave absorbing material in this invention achieves uniform loading of the nanophase, increases the number of heterogeneous interfaces, and enhances dissipation processes such as interfacial polarization, providing a feasible path to solve the common problems of particle agglomeration and impedance mismatch in composite systems.

The present application relates to the field of high-frequency microwave absorbing material and technology, disclose a kind of multifunctional electromagnetic material with high-frequency electromagnetic absorption and corrosion resistance characteristics and its preparation method and application, the multifunctional electromagnetic material is the core-shell structure with 10-100nm particle size, core is metal magnetic alloy component, shell layer is multilayer graphite carbon;It is obtained by carbonization treatment after dissolving and precipitating of metal salt, surfactant and organic ligand, the magnetic alloy component of core body in material and the graphite carbon matrix of shell layer form conductive network, conducive to the conduction loss caused by electron transition;Mutual hetero-interface is conducive to the interface polarization loss of electromagnetic wave.In addition, magnetic component provides strong magnetic loss, optimizes the impedance matching of wave-absorbing body, further enhances the attenuation ability to electromagnetic wave;And shell layer can effectively prevent the penetration and transmission of various corrosive media on the surface of target matrix, it is a kind of multifunctional electromagnetic material with high-frequency electromagnetic absorption and corrosion resistance characteristics.

The invention provides a PEI-based multilayer dielectric composite film containing an inorganic interlayer and a preparation method and application thereof.The PEI-based multilayer dielectric composite film comprises a first layer body, a second layer body and a third layer body which are sequentially arranged in a stacked mode, the first layer body and the third layer body are polyetherimide films, and the second layer body is a polyetherimide film. And the second layer body is a ceramic fiber layer formed by sodium bismuth titanate nanofibers as an inorganic interlayer. The outer-layer pure PEI film provides a high eta value for the PEI-based multilayer dielectric composite film and ensures high breakdown field strength (Eb); the epsilon r value of the composite film is enhanced by the middle layer through the intrinsic high dielectric constant of the NBTNFs and micro interface polarization existing in the contact area of the NBTNFs and the PEI. The multilayer structure can effectively combine respective advantages of different layers, obtains high dielectric constant, high breakdown field strength and low dielectric loss, has high energy storage density and high energy storage efficiency, and can be suitable for various application fields.

The invention provides a step-by-step modification preparation method of a low-agglomeration electromagnetic wave-absorbing putty composite material, and belongs to the technical field of electromagnetic wave-absorbing putty composite materials. The preparation method comprises the following steps: S1, dispersing a micron-sized magnetic filler in a solvent, and drying to obtain surface-modified magnetic powder, S2, dispersing a nano-carbon conductive material in a modifier solution containing a functional group to obtain a surface-modified conductive filler, and S3, adding the surface-modified conductive filler into an organic putty resin matrix, and uniformly dispersing under a three-roller grinding condition to obtain a composite material, and S4, coating the surface of a base material with the composite material to obtain the electromagnetic wave-absorbing putty composite material with a magnetic / electric dual-loss synergistic effect and an interface dissipation enhancement effect. The electromagnetic wave-absorbing putty material with low agglomeration and uniform dispersion is realized through step-by-step chemical modification of the magnetic and conductive filler, reasonable proportioning and a precise control process, has synergistic absorption of magnetic loss, dielectric loss and interface polarization, and is flat in performance, wide in frequency band and easy to prepare.

The application provides a fiber weaving structure dielectric film for a high energy density capacitor and a preparation method, and aims at the fact that the dielectric constant and the breakdown strength of a polymer-based dielectric material are difficult to be simultaneously improved, so that the energy density cannot meet the demand of a high power density energy storage capacitor. A polyetherimide / polyvinylidene fluoride-hexafluoropropylene core-shell structure fiber with a core-shell structure is prepared through a coaxial electrospinning technology, a composite film is formed through laminated hot pressing, the weaving structure is adjusted by adjusting the core-shell fiber composition content, the fiber orientation stacking direction and the stacking layer number, the mechanical strength of the film is enhanced, carriers are captured by deep traps, the breakdown strength is significantly improved, the high dielectric constant is maintained by utilizing interface polarization, and the energy density is comprehensively improved.

The invention belongs to the technical field of anticorrosive materials, and particularly relates to a composite shielding material and a preparation method and application thereof. The composite shielding material comprises fluorocarbon resin and modified graphene oxide, the modified graphene oxide comprises graphene oxide and a silane coupling agent containing a hydrophobic group, and the graphene oxide and the silane coupling agent containing the hydrophobic group are connected through a Si-O-C bond; the oxygen content of the graphene oxide is 5-10 wt%. The composite shielding material has the beneficial effects that under the synergistic effect of the fluorocarbon resin and the modified graphene oxide in the composite shielding material, the surface energy of a coating can be reduced, the super-hydrophobic characteristic is achieved, and a compact interface is achieved on the surface of the coating to block water and oxygen permeation; and due to the moderate conductivity and the interface polarization effect of the modified graphene oxide material, the composite shielding material has good electromagnetic shielding effectiveness.

This invention provides a multi-channel structure for a rapid, highly selective water-voltaic ion sensor, its fabrication method, and its applications. The sensor comprises a multi-channel sandwich-structured fiber membrane, a gradient polarization interface, and an electrode assembly. The multi-channel sandwich-structured fiber membrane includes a first macroporous layer, an intermediate microporous layer, and a second macroporous layer stacked sequentially, dividing the membrane into multiple independent sensing channels on a plane. The gradient polarization interface exhibits different degrees of interface polarization in different sensing channels. The electrode assembly connects to both ends of each sensing channel. The rapid, highly selective water-voltaic ion sensor provided by this invention utilizes a sandwich structure to form ion transport channels with rapid transport at both ends and precise sieving in the middle. This allows for the synergistic enhancement of both rapid ion transport and high-sensitivity response. Furthermore, by constructing differentiated sensing channels with "identical structures but different interfaces," the sensor synergistically amplifies and identifies differences in the intrinsic properties of ions, significantly improving ion selectivity.

This invention relates to a wide-temperature-range structural microwave-absorbing ceramic matrix composite material with a PyC / BN embedded nano-interface and its preparation method. The preparation method of the composite material includes: laminating and shaping a multilayer fiber cloth, depositing a PyC interface on it, introducing Ni particles to etch the continuous PyC interface to form a discontinuous PyC interface, depositing a BN interface to obtain a PyC / BN nano-embedded interface structure, and finally depositing a matrix to obtain the wide-temperature-range structural microwave-absorbing ceramic matrix composite material. This invention, by controlling the PyC / BN nano-embedded interface structure, can reduce conductivity loss and enhance interface polarization loss. The changes in these two losses cancel each other out during heating, resulting in relatively stable electromagnetic wave absorption performance of the ceramic matrix composite material during heating. This achieves excellent electromagnetic wave absorption of over 90% in the X-band across a wide temperature range of room temperature to 1000℃.

A preparation method and application of a hollow core-shell structured Co@SiO2@PPy, belonging to the technical field of electromagnetic wave absorbing materials. The present invention first prepares monodisperse hollow Co microspheres by a solvothermal method. The hollow structure reduces the weight of Co without sacrificing its magnetic loss performance. SiO2 is then coated on the surface of the Co microspheres by a modified Stober method. The introduction of the SiO2 layer not only enhances the interfacial polarization of the composite material but also prevents the Co core from being corroded by acidic solutions and has no significant negative impact on the magnetic loss capacity of Co. Finally, PPy is coated on the surface of the SiO2 layer by in-situ polymerization. PPy has strong electrical conductivity loss due to its high electrical conductivity, and high dielectric loss can be obtained without high-temperature calcination. A hollow core-shell structured Co@SiO2@PPy is used as an electromagnetic wave absorbing material.