79 results about "Fe3o4 nanoparticles" patented technology

The invention discloses a flexible heat-conducting composite material with chain-shaped boron nitride and a preparation method, and belongs to the technical field of flexible electronic device heat management materials, the flexible heat-conducting composite material comprises an elastomer matrix and a magnetic functionalized boron nitride filler filled in the elastomer matrix; the elastomer matrix is polydimethylsiloxane; the magnetic functionalized boron nitride filler is prepared by modifying Fe3O4 nanoparticles on the surface of a boron nitride sheet; the boron nitride sheets form a vertically arranged chain structure in the elastomer matrix. The chained vertical arrangement of the boron nitride sheets is realized by prolonging the magnetic field treatment time, the Fe3O4 modification quantity is controlled to optimize the balance between the magnetic responsiveness and the heat-conducting property, a chained heat-conducting network connected end to end is formed, and the thermal seepage threshold value is reduced. According to the flexible composite material and the preparation method thereof, boron nitride sheets are induced to be vertically arranged through a magnetic field to form a chain-shaped heat-conducting network, so that high heat conductivity under low filler loading capacity is realized, and excellent stretchability is kept at the same time.

The invention belongs to the technical field of biomedical materials, and discloses pH-responsive injectable hydrogel as well as a preparation method and application thereof. Comprising the following steps: (1) dissolving sodium alginate in water to form a uniform solution; (2) adding a fat-soluble small molecule drug and Fe3O4 nanoparticles into the solution, carrying out high-speed shearing dispersion under an ice-water bath condition to form a drug / nano composite system, and standing; and (3) sequentially adding a calcium carbonate suspension and glucolactone into the drug / nano composite system, uniformly stirring, and incubating until the mixture is completely cured to obtain the pH-responsive injectable hydrogel. The hydrogel obtained by the invention not only has excellent injectability and pH response release performance, but also can remarkably improve the loading efficiency of fat-soluble drugs, and provides a new technical approach for realizing local anti-tumor treatment.

The invention belongs to the technical field of SERS (Surface Enhanced Raman Scattering) detection, and relates to a preparation method of an Ag-Fe3O4 composite SERS substrate and application of the Ag-Fe3O4 composite SERS substrate in monitoring trace pollutants in water. Based on a plasma-semiconductor synergistic enhancement mechanism, cubic Fe3O4 nano particles with exposed {100} crystal faces are synthesized through a hydrothermal method, and the cubic Fe3O4 nano particles and Ag nano particles are subjected to ultrasonic-stirring to construct the Schottky heterojunction. The substrate creatively realizes dual-channel enhancement: the local surface plasmon resonance effect of Ag nanoparticles generates electromagnetic enhancement, the narrow band gap of Fe3O4 promotes photo-induced electrons to be transferred to Ag, an interface electric field is formed, and the polarizability of adsorption molecules is remarkably increased. When the probe is applied to detection of trace pollutants in a water body, the probe molecule RB is anchored on the surface of Fe3O4 through carboxyl, and the HOMO energy level of the probe molecule RB and the valence band top of Fe3O4 generate resonance charge transfer, so that the Raman cross section is improved. The detection limit of RB under 0.25 mW laser is increased by several orders of magnitude compared with that of a single Ag substrate.

The invention discloses a magnetic-aptamer targeting tumor tissue nano-drug delivery system as well as a preparation method and application thereof, and belongs to the field of medicines. The system comprises a mesoporous ferroferric oxide magnetic core, a polyethyleneimine (PEI) layer coated outside the mesoporous ferroferric oxide magnetic core and an aptamer adsorbed outside the PEI layer, and an autophagy activator can be selectively loaded in the mesoporous core. The preparation method comprises the following steps: sequentially carrying out drug loading, PEI coating and aptamer modification on the mesoporous Fe3O4 nanoparticles. According to the invention, efficient enrichment and endocytosis of tumor tissues are realized through dual effects of magnetic targeting and active targeting of the aptamer; lysosome escape is promoted by using the proton sponge effect of PEI; finally, by virtue of the synergistic effect of iron ions released by degradation of the Fe3O4 nanoparticles and endogenous iron ions released by ferritin autophagy induced by an autophagy activator, ferroptosis of tumor cells is induced through enhanced Fenton-like reaction, so that high-efficiency and low-toxicity targeted therapy is realized.

This invention belongs to the field of tertiary oil recovery technology, specifically relating to a CO2-switched magnetically driven nanoparticle, its preparation method, and its application. The magnetically driven nanoparticles are silica-coated Fe3O4 nanoparticles. The surface of the silica coating is further modified with amidine groups to act as CO2 switches. These CO2 switches cause the hydrophilicity of the magnetically driven nanoparticles to increase with the increase of CO2 solubility in the solution in which they are located. This invention integrates emulsification and demulsification functions through the CO2 switch loaded on the surface of the magnetically driven nanoparticles. Furthermore, the particles can be recycled using their own magnetic response, reducing costs. This nano-displacement agent can solve the problems of poor efficiency, ineffective oil-water separation, high economic costs, and environmental impact associated with existing displacement agents.

The application belongs to the technical field of medicine preparation, and particularly relates to a magnetic layered double hydroxide, a targeted drug-loaded nano preparation, a preparation method and application of a tumor-targeted drug-loaded nano preparation. The preparation method of the magnetic layered double hydroxide provided by the application can prepare Fe3O4 nanoparticles with small particle size, and further prepare the magnetic layered double hydroxide which can be used as a water-soluble drug carrier. The magnetic layered double hydroxide is used for preparing the targeted drug-loaded nano preparation and the tumor-targeted drug-loaded nano preparation, and can be used for delivering water-soluble drugs such as 5-fluorouracil. The tumor-targeted drug-loaded nano preparation has good dispersity and can be actively targeted to HepG2 cells with high FR expression, has a good inhibitory effect on liver cancer cells, and is expected to provide a potential new treatment system for magnetic chemotherapy.

The invention discloses a three-dimensional network structure magnetic fiber carrier reinforced micro-plastic magnetic separation removal method, which is characterized in that Fe3O4 nanoparticles are selectively precipitated among sepiolite fiber bundle layers by controlling a coprecipitation process, and a wedging effect is generated to realize controllable stripping of fiber bundles, so that a three-dimensional network structure magnetic carrier is formed; a mechanical interlocking structure is formed on the surface of the flexible fiber and the micro-plastic, and the pH of a water body is self-adaptively regulated and controlled through the amphoteric ionization characteristic of silicon hydroxyl; enabling the magnetic aggregate suspension to sequentially pass through a multi-stage gradient magnetic field consisting of a pre-magnetization field, a main separation field and a fine scavenging field, and controlling the flow rate to enable the aggregate to form a stable filter cake layer on the surface of a magnetism gathering medium, so as to realize efficient separation of the micro-plastic; and the magnetic gathering medium capturing the aggregate is subjected to heat treatment, so that the micro-plastic is thermally decomposed, the magnetic carrier is directly recycled, the magnetic performance is improved, and regeneration reinforcement is realized. The micro-plastic removal rate reaches 99% or above, the performance is stable after multiple cycles, and the method is suitable for treating various micro-plastic-containing water bodies.

This invention relates to a high-temperature resistant industrial coating and its preparation method. The method includes: amylating Fe3O4 nanoparticles; grafting the amylated Fe3O4 nanoparticles with polybenzimidazole to obtain PBI-g-Fe3O4 composite particles; in-situ growing MOF to form polyMOF; and surface modification with a hydrophilic silane coupling agent to obtain a hydrophilic modified polyMOF; simultaneously, co-grafting silica nanoparticles with an aminosilane coupling agent and a long-chain alkylsilane coupling agent to obtain a synergist; finally, dispersing all components in an aqueous polyester resin varnish to prepare a composite coating. This invention achieves stable dispersion and strong interfacial bonding of polyMOF in aqueous polyester through a multi-level chemical bonding structure. The synergist synergistically provides curing and defoaming effects. The resulting coating exhibits grade 0 adhesion, excellent defoaming performance, a pencil hardness of 3H, and a temperature resistance limit of 640℃, showing broad application prospects in the field of high-temperature protection.

The embodiment of the invention provides a preparation method of a wave-absorbing and heat-dissipating film and the wave-absorbing and heat-dissipating film. The preparation method comprises the following steps: carrying out amination modification on Ti < 3 > C < 2 > T < x > powder to obtain NH < 2 >-Ti < 3 > C < 2 > T < x > powder; the preparation method comprises the following steps: carrying out carboxylation modification on the Fe3O4 nano particles to obtain the Fe3O4-COOH particles. And mixing the NH2-Ti3C2Tx powder with the Fe3O4-COOH particles, and carrying out an amidation condensation reaction, so as to obtain the Ti3C2Tx-Fe3O4 complex. The preparation method comprises the following steps: dissolving polyvinyl butyral in ethanol, and stirring and mixing to obtain a precursor solution; adding the Ti3C2Tx-Fe3O4 complex and hexagonal boron nitride powder into the precursor solution, and stirring and dispersing to obtain a composite glue solution; and coating a substrate with the composite glue solution, drying, curing, and stripping from the substrate to obtain the wave-absorbing and heat-dissipating film. Multiple interfaces exist between Ti3C2Tx-Fe3O4 and h-BN, electromagnetic waves are reflected and scattered for multiple times between the interfaces with different dielectric constants, and the electromagnetic waves are fully lost. H-BN cooperates with Ti3C2Tx-Fe3O4 to jointly form a stable heat conduction channel, so that heat is rapidly conducted to the surface of the wave-absorbing heat dissipation film from a heat source and dissipated, and the situation of local overheating is reduced.

The application discloses a preparation method of an antibiotic selective adsorbent, first, C-BN nanosheet balls are prepared by a simple catalytic thermal evaporation method; second, the C-BN nanosheet balls are used as a main body to limit and load magnetic Fe3O4 nanoparticles; and then mesoporous SiO2 and imprinted polymers are coated on the surface of the C-BN nanosheet balls in sequence, and the tetracycline antibiotic selective adsorbent is obtained after template molecules are eluted. The tetracycline antibiotic selective composite adsorbent with high adsorption capacity is prepared, the high specific surface area of the carrier material and the enrichment antibiotic capacity of the radial structure and the selectivity of the surface molecular imprinting material are fully utilized, the selective adsorption of specific antibiotics in a complex solution is effectively realized, and the adsorption efficiency is effectively improved. The carbon-doped BN and the limited loading magnetic particles enhance the adsorption capacity, and the adsorbent can be quickly recovered and separated under an external magnetic field. Meanwhile, the SiO2 layer and the imprinted polymers enable the antibiotics to be quickly desorbed, and the cycle number is more, so that the antibiotic selective adsorbent has application prospects in the fields of sewage treatment and food antibiotic detection.

The invention discloses a magnetic amide functionalized covalent organic framework material and a preparation method and application thereof, the preparation method comprises the following steps: S1, uniformly dispersing Fe3O4 nanoparticles and ammonia water, adding tetraethyl orthosilicate, and reacting; s2, a product obtained in the step S1 and 3-aminopropyltriethoxysilane are uniformly dispersed and subjected to a reaction, and aminated magnetic nanoparticles Fe3O4 (at) SiO2-NH2 are obtained; and S3, uniformly dispersing the Fe3O4 (at) SiO2-NH2 and trialdehyde phloroglucinol in a mixed solution of o-dichlorobenzene and N, N-dimethylformamide, adding 4, 4 '-diaminobenzanilide, uniformly mixing, then adding an acetic acid solution, and reacting at the temperature of 100-120 DEG C for 3-5 days to obtain the magnetic covalent organic framework Fe3O4 (at) Am-COFs material. The Fe3O4atAm-COFs prepared by the preparation method disclosed by the invention has a large specific surface area, rapid magnetic separation capability and abundant active sites, so that the adsorption performance of the material on a target object is effectively improved.

The invention relates to a preparation method of a nano-composite microbial agent for efficiently removing kitchen waste grease. Pseudomonas, alcaligenes, bacillus and candida which have high grease degradation capacity are screened out from grease polluted water and kitchen waste compost, and the proportion of the pseudomonas, the alcaligenes, the bacillus and the candida is optimized to form the efficient composite flora. The preparation method comprises the following steps: synthesis of the magnetic Fe3O4 nanoparticles, surface functionalization treatment and synthesis and immobilization of the complex microbial inoculant. The stable and efficient nano-composite microbial agent is prepared by combining the functionalized nano-particles with the composite flora. Experimental verification shows that the complex microbial inoculant shows excellent stability and degradation performance in the application of removing kitchen waste grease, and can be repeatedly used through a magnetic separation technology. Compared with a traditional method, the method has the advantages that the grease removal efficiency is improved, the treatment cost is reduced, and the method has a wide application prospect.

The application discloses a preparation method of fluorine-containing Fe3O4 nano-assemblies and application of the fluorine-containing Fe3O4 nano-assemblies in intracellular protein delivery, and the preparation method comprises the following steps: preparing Fe3O4 nanoparticles and small-molecule ligands containing fluorine alkyl chains respectively, and the two are combined through ligand exchange reaction to form fluorine-containing Fe3O4 nanoparticles; the fluorine-containing Fe3O4 nanoparticles can be self-assembled with proteins to form stable complexes through the hydrophobic effect and electrostatic effect of the fluorine alkyl chains. The fluorine-containing Fe3O4 assemblies provided by the application have universality as intracellular protein delivery carriers, can effectively deliver proteins with different isoelectric points and molecular weights to tumor cells, do not affect the biological activity of the cargo proteins, have small toxicity to cells, and have good biocompatibility. The protein delivery efficiency of the assemblies is further improved under the guidance of an external magnetic field, so that the killing effect of therapeutic proteins on tumor cells is enhanced, and the assemblies have application potential in the field of tumor treatment.

The invention discloses a preparation method and application of magnetic microspheres for drug adsorption. Ferric salt is dissolved in water and heated, an alkaline agent is slowly dropwise added and stirred, cleaning is conducted after the reaction is finished, and Fe3O4 nanoparticles are prepared; the preparation method comprises the following steps: dispersing Fe3O4 nanoparticles in water, heating, adding a double-bond compound, and cleaning after the reaction is finished, so as to prepare Fe3O4 nanoparticles with-C = C-double bonds on the surface; fe3O4 nanoparticles with-C = C-double bonds on the surfaces are dispersed in water, an emulsifier and an active group compound are added, the active group compound is sodium p-styrenesulfonate, vinylpyrrolidone or triethyl (4-vinylbenzyl) ammonium chloride, continuous heating is performed, cleaning is performed after the reaction is finished, and the magnetic microspheres for drug adsorption are prepared. The magnetic microspheres can be fully mixed with sewage through the directional movement of the magnetic microspheres, adsorption, purification and concentration of drugs are completed through anion groups or cation groups, the operation steps of testing are greatly simplified, and the working efficiency is improved.

The invention relates to a preparation method and application of a probe based on wheat germ lectin. The probe is provided with a core-shell structure, and the core-shell structure is provided with a core and a shell wrapping the outer surface of the core. The core of the core-shell structure is Fe3O4 nanoparticles; the shell comprises a first cationic polymer layer, a gold nanoparticle layer, a second cationic polymer layer, a first quantum dot layer, a third cationic polymer layer, a second quantum dot layer and a wheat germ agglutinin layer which are sequentially coated from the outer surface of the core to the outside. The probe has relatively strong magnetic response capability, colorimetric signals, fluorescence signals and capability of capturing various virus glycoproteins; the MAuDQD-coated WGA-LFA method based on the probe provided by the invention is relatively wide in target detection object range, relatively high in detection sensitivity, relatively high in accuracy and relatively short in detection time.

The application discloses a novel composite powder for improving electromagnetic shielding performance and a preparation method thereof, relates to the technical field of electromagnetic functional materials, and comprises a magnetic core, a composite carrier and a surface modification layer; the magnetic core is Fe3O4 nanoparticles; the composite carrier is an inorganic layer coated on the surface of the magnetic core; the surface modification layer is elemental silver (Ag) loaded on the surface of the composite carrier; the composite powder is a core-shell structure, and the chemical formula is Fe3O4-NiSiO3-Ag. The application utilizes the magnetic loss of Fe3O4, the multiple scattering and interface polarization caused by the porous structure of NiSiO3 and the continuous conductive network constructed by elemental silver, realizes excellent impedance matching and wide-frequency strong absorption performance, and solves the technical problems of single loss mechanism and insufficient absorption capacity of the existing electromagnetic shielding materials.

The application belongs to the technical field of enzyme engineering and new material cross, and particularly relates to a kind of immobilized cellulase of magnetic mesoporous core-shell material and preparation method and application. The immobilized cellulase is obtained by physical adsorption of cellulase with magnetic mesoporous core-shell material F5HPU-46 as carrier. F5HPU-46 is a unique core-shell structure with paramagnetic Fe3O4 nanoparticles as core layer and UIO-66 mesoporous shell layer with stable structure, which has the dual advantages of magnetic response and high specific surface area mesoporous structure. The relative enzyme activity of the immobilized cellulase in the application is increased to 119% under acidic conditions at pH 4, while the relative enzyme activity of free enzyme is decreased to 75%.

This invention provides a high-performance polyethersulfone membrane and its preparation method, comprising the following steps: sulfonated polyethersulfone is blended with polyethersulfone and dissolved in a mixed solvent containing ionic liquid, and aminated nano-SiO2 particles are added, followed by ultrasonic dispersion to achieve covalent grafting, resulting in a premix; aminated Fe3O4 nanoparticles are added to the premix, and after ultrasonic dispersion, a crosslinking agent is added and stirred until homogeneous, resulting in a casting solution; the casting solution is degassed until no bubbles are visible, then cast onto a substrate, and coated using a doctor blade, with a magnetic field applied below the doctor blade during the coating process; the coated membrane is immersed in a coagulation bath, and through the synergistic effect of phase inversion and interfacial crosslinking reaction, a polyethersulfone membrane is obtained; the membrane exhibits high water permeability, antifouling properties, and high mechanical strength.

This invention provides a novel synthesis method for producing spherical monodisperse polymer beads that have adjustable diameter, good rigidity and good resistance to organic solvents, and contain sufficient hydrophilic functional groups to promote the uploading of a high percentage of superparamagnetic Fe3O4NP, enabling the production of new monodisperse superparamagnetic polymer beads in the 1-5 μm diameter range for IVD applications. [Solution] A monodisperse superparamagnetic bead having a core-shell structure. The bead includes: a core portion formed from a polystyrene polymer matrix material encapsulating a first batch of superparamagnetic Fe3O4 nanoparticles; a first shell portion directly located on the top of the core portion and formed from a crosslinked polymer matrix material composed of a styrene monomer, a crosslinkable monomer, and a first functional monomer having a functional group; and a second shell portion directly located on the top of the first shell portion.

The invention belongs to the technical field of electrocatalytic materials, and discloses an electrocatalyst for selectively preparing hydrogen peroxide by controlling an oxygen reduction reaction path and application. The electrocatalyst is a composite material in which a Fe3O4 dispersion liquid, an amino-containing monomer, an aldehyde-containing monomer and a zinc salt are subjected to a Schiff base reaction in the presence of a catalyst to obtain a product, and the product and a magnetic metal salt are subjected to a replacement reaction to prepare a metal monatomic covalent organic framework which coats the surface of a magnetic matrix Fe3O4 in a shell form; the Fe3O4 dispersion liquid is prepared by mixing Fe3O4 nanoparticles and a dispersing aid, and the size of the Fe3O4 nanoparticles is smaller than or equal to 100 nm. The electrocatalyst according to the present invention is used to control an oxygen reduction reaction path (2 electron path), thereby achieving high-selectivity production of hydrogen peroxide.

The invention discloses a preparation method of a magnetic modified plant-source alginate biochar adsorption material, which is characterized by comprising the following steps: S1, drying, crushing and sieving plant-source biomass waste, pyrolyzing to obtain plant-source biochar, and mixing the plant-source biochar with a magnetic material, beta-cyclodextrin and an organic acid cross-linking agent to form composite slurry; the magnetic material is Fe3O4 nanoparticles, a magnetic manganese oxide, a magnetic nickel iron oxide or a magnetic cobalt iron oxide; the organic acid crosslinking agent is citric acid; s2, dispersing the composite slurry, adding into a sodium alginate solution, uniformly stirring, and dropwise adding into a calcium chloride solution at normal temperature for cross-linking to form gel ball particles; s3, washing the gel ball particles, and performing freeze drying to obtain the magnetic modified plant source alginate charcoal adsorption material.

The invention discloses a magnetic composite microbial carrier and a preparation method thereof, and belongs to the technical field of preparation of microbial carriers for wastewater treatment. The carrier comprises a magnetic-microbial core, a sodium alginate hydrogel inner layer and a stimuli-responsive electroactive composite outer layer from inside to outside. The core is formed by compounding Fe3O4 nanoparticles modified by citric acid and pseudomonas putida; and the outer layer is prepared from PNIPAM-co-PAA and polyaniline through electrochemical polymerization. The preparation method comprises the following steps: preparing modified magnetic particles and a bacterial suspension, embedding to form gel microspheres, constructing an outer layer through electrochemical in-situ polymerization, and finally performing electrochemical activation and drying to obtain the product. The carrier has adsorption and biological reduction functions, the adsorption capacity retention rate after five times of circulation exceeds 90%, the microbial survival rate exceeds 94%, secondary pollution is avoided, the technical problems that a traditional carrier is low in regeneration efficiency, microbial activity is difficult to maintain and secondary pollution is prone to being generated are solved, and the carrier is suitable for efficient and green remediation of heavy metal polluted water.

The application discloses a preparation method of superfine denier electromagnetic shielding functional chinlon and a product thereof. The chinlon is prepared by mixing 2-7% electromagnetic shielding functional chinlon master batch containing Fe3O4 nanoparticles and 93-98% pure chinlon chips, and then performing drying, melt extrusion, spinning cooling, oiling treatment, drafting setting and winding silk collection. In the preparation process, key parameters such as spinning temperature, filter mesh size, cooling parameter and drafting multiple are optimized, so that the problems of superfine denier fiber spinning breakage, product adhesion and uneven dispersion under high master batch content are solved. The chinlon monofilament fineness obtained by the application is 0.2-0.5 dtex, the breaking strength is greater than or equal to 3.0 cN / dtex, the electromagnetic shielding effectiveness reaches 40 dB in a frequency range of 2000 MHz, the thermal stability is better than that of pure chinlon, and the application is suitable for high-end application scenes such as high-grade clothes, home textiles, electronic protection and filtering materials.

The invention discloses a Br-COF magnetic nanoparticle solid-phase microextraction material as well as a preparation method and application thereof, and relates to the technical field of material preparation and application. The preparation method comprises the following steps: firstly, by utilizing a hydrothermal synthesis method and taking FeCl3. 6H2O as an iron source, partially reducing ferric ions into ferrous iron by ethylene glycol under high-temperature and alkaline conditions, so as to generate magnetic nanoparticles Fe3O4; then, 1, 3, 5-tri (4-aminophenyl) benzene and 2, 5-dibromo terephthalaldehyde are used as monomers, the surface of the magnetic nano Fe3O4 is modified with Br-COF through a solvothermal method, and the cross-linked magnetic extraction material with excellent dispersity is obtained. The COF material structurally contains aromatic rings, bromine atoms and a large conjugated system, the specific adsorption capacity on polybrominated diphenyl ether compounds can be enhanced, the enrichment multiple and extraction selectivity are improved, and therefore the requirement for detecting low-concentration target objects in water environment samples is met.

This invention discloses a method for preparing a wall-mounted magnetic nanoparticle-immobilized enzyme microreactor. The method first involves encapsulating Fe3O4 nanoparticles with polydopamine. Utilizing the self-polymerization properties of dopamine, a uniform polydopamine coating layer rich in active groups is formed on the surface of the Fe3O4 nanoparticles. This provides a high-density reaction site for subsequent activation with a silanizing agent (3-aminopropyltriethoxysilane, APTES) and cross-linking with glutaraldehyde (GA). Subsequently, through multi-level surface functionalization modification involving 3-aminopropyltriethoxysilane activation and glutaraldehyde cross-linking, efficient and stable immobilization of CALB is achieved, while simultaneously endowing the immobilized enzyme with excellent magnetic separation performance, thermal stability, and storage stability. This invention features a simple process, easy operation, and easy recovery.

The invention discloses a preparation method of ultra-suspension magnetic microspheres, which comprises the following steps: S1) taking FeCl3. 6H2O and FeCl2. 4H2O, dissolving, and dropwise adding weak base to prepare Fe3O4 nanoparticles; s2) dispersing the Fe3O4 nano-particles in water, and adding unsaturated acid with carbon-carbon double bonds to prepare Fe3O4 nano-particles with the carbon-carbon double bonds on the surfaces; s3) dispersing Fe3O4 nanoparticles with carbon-carbon double bonds on the surfaces in water, adding a surfactant, adding a functional monomer and the like to prepare magnetic microspheres with active groups; and S4) dispersing the magnetic microspheres with the active groups in ethanol, adding an amino compound to prepare magnetic microspheres of which the surfaces are rich in amino groups, and performing surface modification on the amino groups in the magnetic microspheres of which the surfaces are rich in amino groups to prepare the super-suspended magnetic microspheres. The prepared magnetic microspheres can suspend in a solution for a long time, and the problems of poor process stability and the like caused by sedimentation of the magnetic microspheres or absence of uniform mixing equipment are solved.

The invention provides a titanium alloy milling surface roughness prediction method based on Fe3O4 nano-particle reinforced cutting fluid. The titanium alloy milling surface roughness prediction method comprises the following steps: preparing the cutting fluid containing Fe3O4 nano-particles; establishing a milling force, milling noise and surface roughness acquisition system, and carrying out TC4 titanium alloy wet milling tests under different process parameters; drawing a change curve of milling force, noise and surface roughness test data, and comparing the performance difference before and after addition of the Fe3O4 nanoparticles; and constructing a prediction model based on a convolutional neural network and a relevance vector machine to realize accurate prediction of the surface roughness. The cutting fluid has the advantages that the Fe3O4 nanoparticles are added into the cutting fluid, so that the milling force and noise are remarkably reduced, the surface roughness is improved, and intelligent prediction of the surface quality can be effectively realized by combining experimental testing with a machine learning model.

The invention discloses a preparation method and application of a magnetic protein enzymolysis material, and the preparation method comprises the following steps: growing ferroferric oxide nanoparticles on the surface of porous silica gel with large enough pore size and in pores by adopting an in-situ synthesis method, so that the ferroferric oxide nanoparticles have magnetism; immobilizing protease on the magnetic substrate to prepare a magnetic proteolysis material; putting the material into a protein solution to complete enzymolysis operation; taking out the magnetic protein enzymolysis material from the solution by magnetic separation; the obtained solution after enzymolysis is used for proteomics research. The method disclosed by the invention has the beneficial effects that the enzyme is fixed on the surface of a material in a form that protein forms a protein crown on the surface of the magnetic macroporous silica gel, and free collision and mutual contact among enzyme molecules are limited through a steric hindrance effect, so that the self-degradation probability of the enzyme is greatly reduced; the enzyme immobilization amount is increased, the enzymolysis efficiency is remarkably improved, and the enzymolysis time is remarkably shortened; the magnetically modified macroporous silicon balls can be quickly recovered from a reaction system through an external magnetic field and can be repeatedly used.

The invention relates to the technical field of aerogel, in particular to a silicon dioxide aerogel-aramid fiber composite material with gradient density and a preparation method of the silicon dioxide aerogel-aramid fiber composite material. According to the method provided by the invention, the aramid fiber and the SiO2 / POSS matrix are combined to form the composite insulating material with a three-dimensional interpenetrating network structure through the process steps of sol preparation, gradient gelation and directional forming, and meanwhile, Fe3O4 nanoparticles are modified on the aramid fiber, so that magnetic field regulation and control of fiber orientation are realized. According to the preparation method provided by the invention, the problems of weak interface bonding force, non-uniform fiber orientation and poor performance stability of the aramid fiber-SiO2 composite material in related technologies are solved.

This invention discloses a magnetic molecularly imprinted polymer, its preparation method, and its applications. First, Fe3O4 nanoparticles are prepared via co-precipitation. Then, the Fe3O4 nanoparticles are surface-modified with tetraethyl orthosilicate and 3-(trimethoxysilyl)propyl methacrylate to obtain Fe3O4@SiO2@CH2=CH2 nanoparticles. Using these as the magnetic core of the molecularly imprinted polymer, hexabromocyclododecane is used as the template molecule, 4-vinylpyridine as the functional monomer, azobisisobutyronitrile as the initiator, ethylene glycol dimethacrylate as the crosslinking agent, and acetonitrile as the porogen, to prepare the magnetic molecularly imprinted polymer. The magnetic molecularly imprinted polymer prepared by this invention can rapidly separate hexabromocyclododecane under an external magnetic field with good specificity, exhibiting excellent adsorption and desorption effects. It has low preparation cost, can be recycled, and has good application prospects.