109 results about "Magnetite Nanoparticles" patented technology

The present application belongs to the field of magnetic nanoparticle measurement, and particularly relates to a high-sensitivity magnetic nanoparticle spectrometer and a waveform signal conversion method thereof, and aims to solve the problem that the dynamic magnetic characteristics of low-concentration magnetic nanoparticles cannot be quantitatively evaluated in the prior art. The present application comprises a driving module, a switching module, a current sampling module, a band-pass filtering module, a rectifying module, a current control module, a voltage adjustment module, a coil matching module, a coil assembly, a receiving coil signal processing module, a signal acquisition analog block, and a main control calculation module. According to the target current demand, the coil matching module can be flexibly edited, and further, the control signal for driving the coil can be automatically generated according to the matched driving circuit and the target waveform, wherein the data acquisition-processing link can restore the waveform and obtain the original spectrum of the magnetic particles through the built-in calculation steps. At the same time, the current compensation loop contained in the present application can compensate the current error caused by factors such as coil temperature rise, parameter drift of the matching module, and change of the on-resistance of the switching module, so as to ensure the constant output of the target harmonic current.

The present application belongs to the technical field of plant tissue culture, and particularly relates to a high-efficiency rooting and seedling raising method for plant tissue culture seedlings, S1 trimming and disinfection of S2 induction liquid immersion, S3 composite substrate implantation and gradient environment regulation, S4 substrate transplanting and planting; the core is to use modified magnetic biochar composite substrate loaded with FeO nanoparticles, cooperate with the synergistic effect of microencapsulated rooting hormone and melatonin, realize in-situ integrated seedling raising through composite spectrum containing UV-A, CO pulse supply, gradient humidity and PEG osmotic pressure domestication. The present application effectively inhibits basal browning, shortens the seedling raising period, improves the rooting quality and transplanting survival rate, overcomes the pollution prejudice of magnetic nanoparticles, is suitable for woody and herbaceous plants, and can be applied to plant tissue culture seedling production on a large scale.

This invention discloses a method for reconstructing magnetoacoustic electromagnetic particle images based on time-reversal. This method utilizes the method of moments discretization, combining the voltage-time inversion formula with the theory of the magnetoacoustic electromotive force problem for magnetic particles. It reconstructs the spatiotemporal discrete signals of the first and second derivatives of the voltage acquired by the electrodes into an equivalent field source distribution within the imaging region. A unit current is injected across the electrodes, and the potential distribution is obtained by solving the reciprocal potential Poisson equation. Combining the field source and the reciprocal potential distribution, the discrete divergence field of the magnetic nanoparticle concentration can be calculated, and then expressed as a five-point difference form of the Poisson equation. Finally, the Gauss-Seidel iterative method is used to solve this equation to obtain an image of the magnetic nanoparticle concentration distribution. This invention effectively reduces computational complexity and storage requirements, significantly improves imaging speed, and expands the application potential of this technology in the field of medical imaging.

This invention provides a self-splicing large-size single-crystal diamond substrate and its manufacturing method, belonging to the field of single-crystal diamond technology. The method includes the following steps: in-situ printing a light-treated resin barrier layer on the non-splicing surface of the single-crystal diamond; mechanically grinding the splicing surface of the single-crystal diamond; immersing the splicing surface of the single-crystal diamond in a magnetic nanoparticle precursor dispersion; aligning the splicing surfaces of the single-crystal diamonds to be spliced ​​with each other, applying an external magnetic field in a specific direction to align and tightly adhere the splicing surfaces; subjecting the spliced ​​diamond to high-temperature annealing in a reducing atmosphere or vacuum environment; and placing the spliced ​​diamond in a strong acid cleaning solution to dissolve and remove residual metals and impurities from the diamond surface. This invention utilizes small-size single-crystal diamonds with excellent surface quality for splicing to obtain large-size single-crystal diamonds, preserving the thermal and mechanical properties of single-crystal diamonds while achieving wafer-level large-size expansion.

A single-cell transcriptome-guided multimodal synergistic injectable magnetically responsive biomimetic hydrogel system, its preparation method, and its application are described. This hydrogel platform is a three-level composite system of "matrix-microsphere-nanoparticle": the primary structure is a photocrosslinked methacryloyl hyaluronic acid three-dimensional network matrix; the secondary structure is GelMA microspheres loaded with MTPT nanoparticles prepared by microfluidic control; and the tertiary structure consists of bevacizumab and magnetite nanoparticles dispersed in the HAMA matrix. The MTPT nanoparticles have a mesoporous silica core, which is sequentially coated with temozolomide, a polydopamine coating, and a T7 targeting peptide. Under the activation of an alternating magnetic field, Fe3O4 generates a magnetothermal effect, which not only achieves local hyperthermia but also accelerates the time-sequential release of bevacizumab and MTPT, synergistically exerting the effects of chemotherapy, anti-angiogenic therapy, and hyperthermia.

The application relates to an array type magnetic driving continuous flow system and a catalytic method. The array type magnetic driving continuous flow system comprises at least one reactor unit, and the reactor unit comprises: an upper cover plate and a lower cover plate which are oppositely arranged; a reactor main channel which is arranged between the upper cover plate and the lower cover plate; a solid particle fixing cavity which is arranged in the reactor main channel; magnetic nano particles which are arranged in the solid particle fixing cavity; and a magnetic driving array which comprises at least one group of regularly arranged permanent magnets, the group of permanent magnets are respectively fixed on the upper cover plate and / or the lower cover plate, and can generate a magnetic field which acts on the magnetic nano particles, so that the magnetic nano particles are reversibly fixed in the solid particle fixing cavity. The application effectively solves the problems of the magnetic catalyst in the continuous flow system, such as fixing, mass transfer, flux and recovery, and provides a continuous flow catalytic solution which is efficient, flexible and easy to enlarge.

This invention discloses a method for preparing cationic and amphiphilic quaternized composite magnetic nanoparticles, comprising the following steps: Step S1, preparing magnetic iron oxide nanoparticles using a hydrothermal method; Step S2, preparing silica-coated magnetic iron oxide nanoparticles using the Stober method; Step S3, preparing cationic and amphiphilic quaternized composite magnetic nanoparticles using an electrostatic self-assembly method. This invention uses low-cost alkane quaternary ammonium salts as functional monomers to achieve a three-layer core-shell structure comprising an iron oxide magnetic core, a silica intermediate bridging layer, and an alkane quaternary ammonium salt functional outer layer. The alkane quaternary ammonium salt is stably loaded onto the silica surface through a non-covalent grafting mechanism of electrostatic self-assembly, thereby achieving mild and efficient grafting. The resulting composite magnetic nanoparticles can achieve efficient separation of emulsified oily wastewater at room temperature and exhibit excellent recyclability, salt tolerance, and wide pH adaptability.

The application discloses a kind of magnetic nanocomposite and its application in dye wastewater treatment, belong to water treatment functional material technical field.The magnetic nanocomposite with Fe3O4 Magnetic Nanoparticle as core, successively coats silica layer, graphene nanosheet layer and chitosan crosslinking layer, through the synergistic effect of chitosan liquid ultrasonic modification and graphene nanosheet surface modification, realize efficient adsorption and magnetic separation recovery to dye molecule.The preparation process of the application is mild controllable, environment-friendly, cost moderate, has wide application prospect in printing and dyeing wastewater advanced treatment, industrial dye pollution control field, graphene nanosheet greatly promotes specific surface area and adsorption site, chitosan provides a large number of amino / hydroxyl active groups, three synergies realize high adsorption capacity.Graphene nanosheet is reduced by liquid phase ultrasonic stripping, avoids stacking;Chitosan is modified by ultrasonic and TiO2 is scattered, combination is more firm, material structure is stable, not easy to lose, acid and alkali resistant.

The application discloses a kind of magnetic nanoparticles for atherosclerosis diagnosis and treatment.It is core-shell structure, the inner core is Fe₃O₄ magnetic nano material, shell is the drug-loading layer of biodegradable polymer material, the drug-loading layer is encapsulated with analog movement polypeptide K271la, and the surface of nano particle is covalently coupled with CD36 targeting antibody.Its preparation method mainly includes: by complex emulsification-solvent volatilization method, Fe₃O₄ nanoparticle and K271la polypeptide are co-encapsulated in one step, form nanoparticle, and then CD36 antibody is modified on the surface of particle by chemical coupling.The nanoparticle of the application has the ability of active targeting (CD36 antibody) and passive targeting (magnetic response), can be efficiently enriched in plaque, and deliver therapeutic polypeptide to macrophages, activate lipophagy to remove lipid;It can be used as magnetic resonance imaging contrast agent, realizes diagnosis and treatment integration, and provides a new strategy for solving the problem of low efficiency of atherosclerosis targeted therapy and lack of effective monitoring means.

This invention discloses a magnetic amorphous carbon composite aerogel fiber, its preparation method, and its applications, belonging to the field of electromagnetic functional materials. The aerogel fiber has a continuous fiber morphology, composed of an amorphous carbon three-dimensional network framework and uniformly embedded MOF-derived magnetic nanoparticles. The core of its preparation method involves blending transition metal MOF nanoparticles with aramid nanofiber dossile, wet spinning through a unique "MOF-induced-protonation" synergistic gelation mechanism, followed by high-temperature carbonization, which transforms the MOF into magnetic particles in situ and anchors them within the carbon framework. This method is highly versatile and applicable to various MOFs such as Fe, Co, Ni, and Mn, and is simple and can be continuously produced. The resulting aerogel fiber possesses ultra-low density, high flexibility, and excellent broadband strong absorption performance (effective absorption bandwidth ≥ 7.0 GHz, reflection loss ≤ -50 dB), showing broad application prospects in wearable electronics, aerospace stealth, and 5G communication electromagnetic protection.

The application relates to the technical field of biological detection, and particularly discloses a rapid detection kit for Helicobacter pylori and an application method thereof; the kit comprises a sample processing liquid, an antigen pre-enrichment particle suspension and an immunochromatography test paper card; the sample processing liquid comprises an antigen-induced release system, a composite lysis system, a matrix interference blocking system and a chromatography promoter; the antigen pre-enrichment particle is a magnetic nanoparticle with an anti-Helicobacter pylori antibody coupled on the surface; and the immunochromatography test paper card is provided with a first detection line, a second detection line and a quality control line on a nitrocellulose membrane in sequence. The antigen is mildly and efficiently released through the antigen-induced release system, the bacterial cell wall is synergistically lysed through non-ionic and anionic surfactants, the interference substance is blocked through a double mechanism of a protein blocking agent and a metal ion chelating agent, the low-abundance antigen is enriched through the magnetic nanoparticle, and the sample effectiveness is monitored through the second detection line.

The present invention describes novel drug-carrying nanoparticles called bionanocarriers capable of modulating the cellular redox system and targeting the cancerous tumor.Specifically, the invention relates to a nanomedicine strategy for combating cancerous tumor cells, a strategy that aims to target the tumor, and consists of providing quercetin-linked magnetite nanoparticles (Q): (MNPs Q), and 3,5-dimaleylbenzoic acid-linked magnetite nanoparticles (A3'5DMB): (MNPs A3'5DMB)M; both types of nanoparticles were subsequently encapsulated with chitosan (Qs) and O-carboxymethyl chitosan (O-CMQs), functionalized with 11-mercaptoundecanoic acid (MUDA), and finally the anti-ABCC3 antibody was attached to the polymer phase, which was used as a selective driver of the delivery process of the encapsulated nanoparticles, thus carrying out the construction of the bionanocarriers: BNC-1: MNPs-Q-Ab; BNC-2: MNPs-a3'5DMB-Ab.Its manufacturing method and the tests of its biological functionality, its stability, the degradation of the encapsulation for the tumor microenvironment, the controlled release profile of the drugs Q and A3'5DMB, selective cell uptake, intracellular localization, cytotoxic effect on steroids of hepatocellular carcinoma cells with altered redox balance and induction of apoptosis, as well as its safety on normal cells, are described.

The application relates to the technical field of metal recovery, in particular to a metal removal and recovery method for waste titanium anode plates; nanometer particles are subjected to a coating operation, cations are introduced to graft the coated nanometer particles, grafted nanometer particles are obtained, and the grafted nanometer particles are pretreated to obtain initial nanometer particles. In the application, the metal recovery of the waste titanium anode plates is realized through the synergistic effect of magnetic nanometer particle synthesis, functional modification and biological enzyme directional degradation; the surface of the nanometer particles is subjected to double-layer coating of silicon dioxide-polyacrylic acid and synergistic modification of carboxyl and amino groups, the adsorption capacity and selectivity to noble metal ions are enhanced, the noble metal ions are reduced to metal states through catalysis of an active enzyme solution, an integrated process of adsorption to degradation and then magnetic separation is formed between the noble metal ions and the functional nanometer particles, and after the titanium matrix is regenerated through pickling, high-value recovery and utilization of metal materials can be realized through smelting or powder metallurgy.

This application provides a magnetic nanoscale temperature measurement method, device, electronic device, and storage medium based on particle size distribution correction, relating to the field of nanomaterials technology. The method includes: acquiring the electron paramagnetic resonance (EPR) spectrum of magnetic nanoparticles in a target environment, as the target EPR spectrum; extracting the positive and negative peak amplitudes, resonance magnetic field, and peak-to-peak width from the target EPR spectrum, as the target positive and negative peak amplitudes, target resonance magnetic field, and target peak-to-peak width; and calculating the temperature corresponding to the target positive and negative peak amplitudes, target resonance magnetic field, and target peak-to-peak width based on a pre-constructed temperature measurement model, as the temperature of the target environment. The temperature measurement model characterizes the relationship between temperature and the positive and negative peak amplitudes, resonance magnetic field, and peak-to-peak width of the EPR spectrum of the magnetic nanoparticles. The temperature measurement model is constructed based on the particle size distribution of the magnetic nanoparticles. Using this embodiment can improve the accuracy of magnetic nanoscale temperature measurement.

The application belongs to the technical field of water treatment, and particularly relates to a phosphorus-containing modified magnetic chitosan microsphere, a preparation method thereof and application of the phosphorus-containing modified magnetic chitosan microsphere in treatment of chromium-containing underground water. Compared with the prior art, the phosphorus-containing modified magnetic chitosan microsphere provided by the application takes magnetic nanoparticles as a core, can be quickly separated from a reaction system by relying on external magnetic force of a system, and forms hydrogen bonds through hydroxyl groups of the magnetic nanoparticles and amino groups and hydroxyl groups of a chitosan molecular chain, so that stability and dispersibility of the magnetic nanoparticles are improved. Furthermore, a tetramethylammonium hydroxide solution is used as a crosslinking agent, so that a phosphorus-containing cationic group in the tetramethylammonium hydroxide is grafted on the chitosan molecule, thereby greatly enhancing adsorption performance of the chitosan on anionic heavy metal pollutants such as Cr(VI), and having long-term stability in remediation of Cr(VI)-contaminated underground water.

This invention discloses a magnetic fluorescently imprinted nanoparticle, its preparation method, and its application. The nanoparticle comprises amino-functionalized magnetic nanoparticles and a fluorescently imprinted polymer layer coated on their surface, wherein the fluorescently imprinted polymer layer has an imprinted cavity; the imprinted molecule in the fluorescently imprinted polymer layer is a cTnI-specific C-terminal epitope peptide. Functional monomers are screened using computational chemistry, and nanomolecularly imprinted polymers (MIPs) are synthesized using epitope imprinting technology. Fluorescent monomers are introduced to impart autofluorescence response properties, forming a label-free detection system. These nanoparticles exhibit highly efficient adsorption and specific recognition of cTnI protein, with a detection sensitivity of 1 pg / mL (R²=0.98). They show extremely low non-specific adsorption to common interfering proteins and effectively resist interference from complex biological matrices, providing a new approach for rapid clinical cTnI detection.

The application discloses a kind of bifunctional magnetic nano material and its preparation method and application.The nano material described in the application is Fe3O4@ZrO2@TiO2@mSiO2-L-Cys, with spherical structure;The material includes successively from inside to outside: the inner core is the magnetic nanoparticle of ferriferrous oxide;Intermediate layer is zirconium dioxide and titanium dioxide composite metal oxide layer;Sub-outer layer is mesoporous silica layer;The outermost layer is the L-cysteine molecular layer grafted by zirconium-sulfur chemical bond;The preparation method described in the application adopts solvothermal method to synthesize magnetic core, functional layer is coated by hydrothermal reaction, co-condensation method constructs mesoporous shell, and hydrophilic group is introduced by chemical grafting.The bifunctional magnetic mesoporous nano material prepared in the application is applied to the effective enrichment of glycopeptide and phosphopeptide in standard protease solution mixture, and the detection sensitivity of phosphopeptide and glycopeptide reaches 1 fmol / μL, which has wide prospect in glycopeptide and phosphopeptide proteomics analysis research.

The application relates to a skin repair essence and a preparation method thereof. The skin repair essence comprises the following raw materials in percentage by weight: 0.2-0.6% gold-coated magnetic nanoparticles, 75-92% skin repair culture medium, 0.4-1.2% antioxidant and 0.1-1.3% humectant, and the rest is deionized water; wherein the skin repair culture medium comprises a cell in-vitro culture medium, a sturgeon caviar extract, a lactobacillus fermentation product and a brown algae extract; the cell in-vitro culture medium comprises low-sugar DMEM, RPMI-1640, MEM and protein peptides; the antioxidant comprises green tea extract, vitamin C, oat kernel extract and yeast extract; and the humectant comprises trehalose, xanthan gum and sodium hyaluronate. The scheme provided by the application can achieve the purpose of relieving aging by repairing damaged skin cells, and effectively improves the skin repair effect in a safe and effective manner.

This invention relates to a process for treating acidic mine wastewater (AMD). The process includes the following steps: adjusting the pH of the AMD to a range of 3 to 5; adding magnetite nanoparticles to form a slurry; and a) aerating the slurry obtained in step 3), or b) simultaneously heating and mixing the slurry obtained in step 3). The magnetite nanoparticles loaded with one or more metals and sulfate ions and precipitated metals are then separated from the slurry.

Disclosed are a method, device, and system for X-ray CT contrast imaging using magnetic nanoparticles. The method includes: rotating a target object containing magnetic nanoparticles as contrast agent for one circle relative to X-rays, recording multiple consecutive transmission projection images of the target object at all angles; for multiple transmission projection images at each angle, after conducting image post-processing operations, performing inverse projection transform on magnetic nanoparticle imaging projection images at all angles to obtain a tomographic imaging result. The image post-processing operation includes: time-frequency transform: converting the third dimension of the three-dimensional time domain matrix to frequency domain to obtain a three-dimensional frequency domain matrix; feature extraction: selecting a two-dimensional matrix with frequency of kf along the third dimension of the three-dimensional frequency domain image matrix; k is a positive integer; f is the frequency of the excitation magnetic field.

The application discloses a kind of magnetic porous composite material and its preparation method and the application of adsorbing and purifying micro-nano plastic in water body.The magnetic porous composite material has three-dimensional network skeleton formed by microcrystalline region and hydrogen bond physical crosslinking between polyvinyl alcohol molecular chains, cationic polymer is physically inserted and distributed in the skeleton to provide cation adsorption sites, and magnetic nanoparticles are dispersed in the network;After freeze-drying, a hierarchical porous network structure containing 50-300 μm interconnected macropores and 3-10 nm mesopores is formed, wherein the interconnected macropores serve as mass transfer channels, and the mesopores and cation adsorption sites cooperate to achieve physical entrapment and electrostatic adsorption of micro-nano plastic.The present application does not require any chemical crosslinking agent, can be quickly separated by an external magnetic field, has the advantages of high adsorption efficiency, strong environmental adaptability, easy magnetic separation and multiple cycle regeneration, and is suitable for the enrichment, detection pretreatment and purification of micro-nano plastic in water body.

This invention discloses a method and apparatus for enhancing heat transfer between magnetic molten salt nanofluid and sCO2 through thermomagnetic coupling. The method introduces magnetic molten salt nanofluid and manipulates it using an external magnetic field, constructing a heat transfer model synergistically integrating a velocity field, a temperature gradient field, a pressure gradient field, and a magnetic field. Numerical simulations are used to obtain the velocity, temperature, and pressure distributions of the fluid, allowing analysis of the directional aggregation behavior of magnetic nanoparticles in the wall region, forming a stable thermal conductivity network and significantly reducing wall thermal resistance. Furthermore, response surface methodology (RSM) combined with neural network technology is employed to optimize the angle parameters between the velocity field and the magnetic field, temperature gradient field, and pressure gradient field. α , β , gamma This method achieves optimal configuration of multi-physics coupling, further improving heat exchange efficiency. It provides new ideas and technical support for the design of high-efficiency thermal management systems.

The application discloses a kind of electromagnetic shielding adhesive tape based on composite electromagnetic nanoparticle layer and preparation method thereof, belong to electromagnetic shielding material this technical field, its design key points are in, from top to bottom in turn: protective layer, FeNi metal layer, composite electromagnetic nanoparticle layer, adhesive layer and release layer;The composite magnetic nanoparticle layer is the particle layer with the thickness of 10-30 μm formed by conductive polymer matrix and magnetic nano composite;The conductive polymer matrix is PPy or PANI, and the magnetic nanoparticle is Fe3O4 nanoparticle or CoFe nanoparticle.The technical scheme of the present application combines the magnetic permeability of FeNi metal layer and the characteristics of the electric loss and magnetic loss of the composite magnetic material layer (high magnetic permeability soft magnetic and conductive polymer combination), can simultaneously reflect and absorb electromagnetic waves, and the magnetic permeability guiding mechanism has excellent electromagnetic shielding efficiency in a wide frequency range, especially in low frequency and static magnetic field.

Provided herein are methods of determining molecular binding kinetics on particles, such as magnetic nanoparticles. In some embodiments, the methods include introducing an incident light from a light source toward a sample container that comprises a particle-bound biomolecule-ligand composition comprising a plurality of particle-bound biomolecules and a plurality of ligands that binds, or is capable of binding, to biomolecules of the plurality of particle-bound biomolecules, detecting light scattered from particle-bound biomolecule-ligand complexes in the particle-bound biomolecule-ligand composition over a duration to produce a set of imaging data using the detector, and determining size or volume changes of one or more of the particle-bound biomolecule-ligand complexes during at least a portion of the duration from the set of imaging data to thereby determine the molecular binding kinetics on the particles. Related systems and computer readable media are also provided.

This invention discloses a multi-stimulus-responsive upconversion luminescent nanocrystalline magnetic microsphere and its preparation method, belonging to the field of biomedical polymer materials and nanobiotechnology. The microsphere's main body is a porous copolymer matrix, encapsulating a core of magnetite (Fe3O4) magnetic nanocrystals. Rare-earth-doped fluoride upconversion luminescent nanocrystals are coupled to the surface and pores. The copolymer side chains of the microsphere incorporate azide groups, acidic stimulus-responsive groups, and photostimulation-responsive groups, constructing an independent and non-interfering triple orthogonal logic gating system on the surface. The preparation method includes preparing an oil phase containing copolymers, magnetic nanoparticles, and a volatile porogen; pre-emulsifying and homogenizing the oil phase in an acidic aqueous phase using an SPG membrane; inducing phase separation by controlled solvent evaporation to form porous microspheres; and finally coupling the upconversion nanocrystals via a click chemistry reaction. The magnetic microspheres of this invention eliminate background fluorescence interference from complex samples from a physical perspective. Their porous structure endows the microspheres with excellent quasi-levitation properties and magnetic responsiveness, effectively solving problems such as single surface function and signal crosstalk of microspheres. They are suitable for in vitro clinical diagnosis and complex analysis of multiple targets.

The application belongs to the technical field of biological detection, and particularly relates to a high-throughput biological macromolecule detection and separation integrated method and system, which comprises the following steps: providing a magnetic nanoparticle sample with uniform particle size, connecting biological macromolecules with different molecular weights or conformations on the surface of each magnetic nanoparticle to obtain a to-be-detected sample solution; after a background magnetic field with a specific intensity and direction and a gradient magnetic field with a certain gradient size are applied to the solution, the magnetic nanoparticles with different types of biological macromolecules connected on the surface will present different motion trajectories, so that the effective separation of different biological macromolecules in the liquid can be realized; then, the magnetophoretic velocity of each magnetic nanoparticle is extracted through imaging, and the type of biological macromolecule can be deduced from the velocity. The application can utilize the steady-state magnetophoresis characteristics of the magnetic nanoparticles under the conditions of saturated magnetization and strong gradient magnetic field, realize continuous characterization based on velocity information, and break through the technical bottleneck that the traditional magnetic separation technology only relies on the end-point capture or enrichment result and cannot reflect the difference in dynamic behavior of the magnetic nanoparticles.

The application discloses a kind of porous carbon / magnetic nanoparticle composite and its preparation method and application, the composite described in the application is that shaddock skin powder is mixed with cobalt source, 2,5-dihydroxy p-phenylenediamine terephthalate in solvent, precursor is obtained by hydrothermal reaction, and it is prepared by high-temperature carbonization under inert atmosphere.The morphology, size and graphitization degree of the magnetic nanoparticles in the composite can be effectively controlled by regulating the carbonization temperature in the application, so as to optimize the impedance matching and electromagnetic wave attenuation capacity of the material, and the composite prepared has excellent electromagnetic absorption performance, the minimum reflection loss value (RL min ) can reach-36.93 dB, and the effective absorption bandwidth (EAB) can reach 4.77 GHz, and has wide application prospect in the field of electromagnetic wave absorbing materials.

The application discloses a preparation method of amino-modified magnetic microspheres, which comprises the following steps: modifying the surface of magnetic nanoparticles to obtain magnetic microspheres with double bonds on the surface; performing a polymerization reaction on the surface of the magnetic microspheres to form core-shell magnetic beads with a surface polymer; and performing an amino-modification treatment on the core-shell magnetic beads to form amino-modified magnetic microspheres. The magnetic microspheres have strong magnetism, uniform particle size distribution, regular morphology, and small batch difference, and the sensitivity of magnetic bead extraction is greatly improved.