282 results about "Cobalt ferrite" patented technology

The invention discloses a preparation method of nano ferrate/carbon nano tube composite materials, which utilizes a carbon nano tube as a supporting material and adopts a method of solvothermal synthesis to prepare a series of nano ferrate/carbon nano tube composite materials which are even in dispersion, have magnetic property, include nano cobalt ferrite/carbon nano tubes, ferrous acid nickel/carbon nano tubes, ferrous acid copper/carbon nano tubes, zinc ferrite/carbon nano tubes, ferrous acid manganese/carbon nano tubes and the like, and have certain universality. Compared with the prior art, the preparation method of the nano ferrate/carbon nano tube composite materials utilizes ethanol as solvent. The prepared nano materials are uniform in grain size and excellent in performance and have good application prospect and economic benefits on aspects of photocatalysis sewage treatment, lithium ion batteries and the like.

Processing techniques for forming a textured hexagonal ferrite materials such as Z-phase barium cobalt ferrite Ba₃Co₂Fe₂₄O₄₁ (Co₂Z) to enhance the resonant frequency and other magnetic properties of the material for high frequency applications are provided. The processing techniques include magnetic texturing by using fine grain particles and sintering the material at a lower temperature than conventional firing temperatures to inhibit reduction of iron. The processing techniques also may include aligning M-phase (BaFe₁₂O₁₉ uniaxial magnetization) with non-magnetic additives in a static magnetic field and reacting with BaO source and CoO to form Z-phase (Ba₃Me₂Fe₂₄O₄₂). In some implementations, processing techniques includes aligning Co₂Z phase (planar magnetization) with magnetic texturing occurring in a rotating magnetic field.

The invention discloses an expandable graphite/polyaniline/cobalt ferrite wave-absorbing material with an anti-electromagnetic interference function and a preparation technology thereof. The invention aims to provide an expandable graphite/polyaniline/cobalt ferrite wave-absorbing material which has strong electromagnetic wave absorbing capability and wide absorption frequency bandwidth and is convenient to use without causing environmental pollution and a preparation technology thereof. According to the invention, the wave-absorbing material consists of paraffin serving as a film forming material and an expandable graphite/polyaniline/cobalt ferrite ternary complex serving as an electromagnetic wave absorbent. The preparation technology of the expandable graphite/polyaniline/cobalt ferrite wave-absorbing material comprises the following steps of: (1) preparing expandable graphite; (2) preparing absolute ethyl alcohol containing expandable graphite; (3) preparing an expandable graphite/polyaniline binary complex; (4) preparing the expandable graphite/polyaniline/cobalt ferrite ternary complex; and (5) weighing the expandable graphite/polyaniline/cobalt ferrite ternary complex and the paraffin, uniformly mixing the expandable graphite/polyaniline/cobalt ferrite ternary complex and the paraffin and performing ball milling to obtain the expandable graphite/polyaniline/cobalt ferrite wave-absorbing material.

The invention relates to a 2-2 type ferroelectrics-ferrite multilayer composite magnetoelectric material and the preparation method, which relates to a ferroelectrics-ferrite multilayer composite magnetoelectric material. The invention consists of a ferroelectrics and a ferrite, the ferroelectrics and the ferrite materials are composed by adopting a layered alternate arrangement mode, wherein, the ferroelectrics material selects a lead zirconate titanate PbZr0.52Ti0.48O3 ceramics, and the ferrite selects a cobalt ferrite CoFe2O4 ferrite ceramics. An organic solvent, a plasticizer, a dispersant and a bonding agent are added in PZT powder and are ball milled and mixed to obtain a paste; the paste is treated with screening, defoaming and doctor blade casting to obtain an electrolyte thin film green, demoulding and cutting are carried out; the organic solvent, the plasticizer, the dispersant and the bonding agent are added in CFO powder and are ball milled and mixed to obtain the paste; the paste is treated with screening, defoaming and doctor blade casting to obtain the electrolyte thin film green, the demoulding and cutting are carried out; the PZT green and the CFO green are overlapped alternatively, a multi-layer composite green material is obtained by heating and pressurizing, roasting and hydrostatic pressure processing are carried out, and then sintering and molding are carried out for preparation.

The invention discloses a layered MXene loaded cobalt ferrite composite wave-absorbing material. The cobalt ferrite of the composite wave-absorbing material is loaded between layers of layered MXene, and the mass ratio of the cobalt ferrite to the layered MXene is 1: (1-3), wherein the MXene has a unique lamellar microstructure, and the surface of the MXene is rich in functional groups, so that the cobalt ferrite can be loaded between layers or on the surface of the MXene to form a dielectric-magnetic two-phase heterojunction microstructure, and the MXene has a remarkable dielectric polarization loss characteristic; the nano magnetic cobalt ferrite loaded on the MXene has a high-frequency natural resonance effect and a strong magnetic loss mechanism, and the high resistivity of the nano magnetic cobalt ferrite can weaken the strong reflection effect of the MXene on incident electromagnetic waves, so that the composite material is more beneficial to impedance matching with space; therefore, the composite material shows a broadband strong electromagnetic wave absorption characteristic, and a reflectivity result shows that the bandwidth of the composite material is superior to -10dB (90% absorption rate) and reaches 7.2 GHz, and a corresponding absorption peak reaches -21.75 dB.

The invention provides a preparation method of dark-blue zirconia ceramic. The method comprises following steps: step one, taking zirconia powder as the base material, adding at least one component from following components: cobalt ferrite, cobalt oxide and cobalt aluminate in the zirconia powder as the coloring agent, and adding polyvinyl alcohol water solution in the zirconia powder as the binder; step two, putting the mixture of the ceramic raw materials prepared in the step one into a ball-grinding bottle to grind until the mixture is homogenously mixed, pouring out the suspending liquid in the ball-grinding bottle, drying the suspending liquid to remove the water, and obtaining ceramic powder; step three, pressing the ceramic powder obtained in the step two into required ceramic bodies through the dry pressing technology or the isostatic pressing technology; step four, putting the ceramic bodies obtained in the step three into a high-temperature sintering furnace after slow glue discharging to sinter into products. The preparation method produces a dark-blue zirconia ceramic, and the ceramic contains a coloring material. The coloring material can stably exist at the temperature of 1500 DEG C, furthermore, the coloring material not only can guarantee that zirconia is sintered into a completely compact state, but also makes the zirconia ceramic have a dark-blue appearance.

The invention discloses a nitrogen-doped graphene/cobalt ferrite nano composite material and a preparation method thereof. The preparation method comprises the following steps: putting graphite oxide into absolute ethyl alcohol and carrying out ultrasonic treatment; adding cobalt nitrate and iron nitrate into the absolute ethyl alcohol; adding a dissolved metal salt solution into a graphene oxide solution to carry out ultrasonic dispersion again; adding urea into the uniformly-dispersed mixed solution; agitating and dissolving; finally, carrying out a hydro-thermal synthesis reaction on the mixed solution; after the reaction is finished, centrifugally washing and drying a product to obtain a composite material. According to the preparation method, the urea is used for reducing graphene oxide; in the reduction process, nitrogen atoms are doped on the surface of graphene; the doping of nitrogen atoms changes the surface chemical properties of the graphene to make up the surface defects formed by preparing the graphene by a chemical method; the alkalinity provided by the urea enables cobalt ferrite to be formed on the surface of the nitrogen-doped graphene; nano particles of the cobalt ferrite can further prevent layers of the graphene from being accumulated and reunited, and the electrochemical performance of the composite mateial is improved.

The invention adopts an in-situ oxidation polymerization method and enables the polyaniline to be wrapped on the surface of the magnetic ferrate, and a series of ferrate/polyaniline magnetic nano composite materials can be prepared by using the method and comprise cobalt ferrite/polyaniline, nickel ferrite/polyaniline, copper ferrite/polyaniline, zinc ferrite/polyaniline and manganese ferrite/polyaniline and the like. A prepared ferrate/polyaniline magnetic nanometer catalytic agent has obvious preferential adsorption performance and good photoelectrical activity, and has good application prospects and economic benefits in the fields of adsorption, photocatalysis, lithium ion batteries and the like.

The invention relates to ferroelectric/ferromagnetic compound materials, in particular to a preparation method for 0-3 compound multiple-ferrite ceramic of cobalt ferrite and lead lanthanum zironate titanate, which is characterized in that lead lanthanum zironate titanate is used as a ferroelectric phase in multiple-ferrite ceramic, cobalt ferrite is used as a ferromagnetic phase in the multiple-ferrite ceramic, zirconium oxide sol is wrapped on the surface of the ferrite phase of the cobalt ferrite through sol-gel technology to form a zirconium dioxide coating layer through pyrolysis, 3-8% of LiBiO3 is added into the lead lanthanum zironate titanate to serve as low temperature sintering aid to perform low temperature sintering, the cobalt ferrite wrapped the zirconium dioxide on the surface is mixed with the lead lanthanum zironate titanate sintered at the low temperature according to the mass ratio of 0.1 to 0.5:1, and then mixture of the cobalt ferrite and the lead lanthanum zironate titanate are granulated, pressed and sintered to be prepared into compound ceramic. The preparation method enables CFO and lead lanthanum zironate titanate (PLZT) powder to be compounded and sintered, thereby being simple in process, low in cost and easy to achieve industrialized batch production.

The invention provides a method for preparing multiaperture spherical magnetic ferrite (zinc ferrite, nickel ferrite, cobalt ferrite and manganese ferrite) by taking dodecylamine as a precipitator by a solvothermal method. The preparation method is characterized in that an ethylene glycol solution of ferric trichloride and chloride is used as a reaction solution; dodecylamine is used as the precipitator; and the ethylene glycol solution and the dodecylamine are stirred and mixed uniformly at the room temperature to form a liquid phase reaction solution; and the liquid phase reaction solution is transferred to a reaction kettle for hydrothermal reaction at 180-250 DEG C. Products are separated, washed and dried to obtain corresponding multiaperture ferrite powder after reaction. The preparation method has the characteristics of being low in raw materials, simple in process, convenient in operation, controllable in shape, and the like.

A process for preparing nano-class cobaltic ferrite includes such steps as proportionally dissolving the water-soluble Fe salt and Co salt in water, high-speed stirring while slowly adding alkali or acid to regulate pH=11-13, stirring to become suspension, immersing in boiling water bath, washing with deionized water, filtering to obtain brown deposit, heat treating to become suspension, dispersing, and vacuum freeze drying to obtain granular cobaltic ferrite.

The invention discloses one-dimensional magnetic Fe-Co alloy/cobalt ferrite composite nano-fibers and a preparation method thereof. The diameter of the nano-fibers is 50 to 100 nanometers; a Fe-Co alloy phase has a body-centered cubic structure; the nano-fibers have good magnetism at room temperature; and the phase composition of the composite nano-fibers can be effectively adjusted and controlled by changing the roasting temperature of the cobalt ferrite nano-fibers and the reduction temperature and time of the cobalt ferrite nano-fibers in a hydrogen atmosphere, and the alloy phase content of the nano-fibers changes between about 10 weight percent and nearly 100 weight percent. The preparation method comprises the following steps of: firstly, preparing composite precursor nano-fibers of polyvinylpyrrolidone and related metal inorganic salts by electrostatic spinning; then, preparing pure-phase crystalline cobalt ferrite nano-fibers through high-temperature roasting; and finally, performing reduction treatment on the obtained cobalt ferrite nano-fibers in the hydrogen atmosphere to obtain the Fe-Co alloy/cobalt ferrite composite nano-fibers consisting of different phases.

The invention relates to a ferrite nanometer superstructure porous material and a method for preparing the same, in particular to a method for preparing a nickel ferrite, cobalt ferrite or zinc ferrite nanometer superstructure porous material. The preparation method comprises that: sodium oxalate is used as a precipitator, the soluble nickel, cobalt or zinc salt used as a raw material reacts with the soluble iron salt to prepare a precursor of oxalate, and the precursor is degraded by calcination at certain temperature to obtain the nickel ferrite, cobalt ferrite or zinc ferrite nanometer superstructure porous material. The nickel ferrite, cobalt ferrite or zinc ferrite nanometer superstructure porous material synthesized by the method has the advantages of high purity, uniform size, good dispersibility, mild reaction conditions, simple equipment, easily controlled process conditions and low cost, and meets the need of the actual production.

The invention discloses a nitrogen-doped graphene/cobalt ferrite/polyaniline nanometer composite material and a preparation method thereof. The preparation method comprises the following steps of carrying out ultrasonic dispersion on graphite oxide in ethanol; then adding cobalt nitrate and ferric nitrate to the ethanol; adding a dissolved metal salt solution to a solution, then carrying out the ultrasonic dispersion again; adding carbamide to a mixed solution, and stirring for dissoluton; finally carrying out hydro-thermal synthesis reaction on the mixed solution; after the reaction is finished, centrifugalizing, washing and drying a product to obtain a nitrogen-doped graphene/cobalt ferrite nanometer composite material; carrying out the ultrasonic dispersion again on the obtained composite material in absolute ethyl alcohol; adding a phenylamine monomer under the condition of ice bath, uniformly stirring, and then dropwise adding doping acid and an oxidizing agent; centrifugalizing, washing and drying an obtained product to obtain the nitrogen-doped graphene/cobalt ferrite/polyaniline nanometer composite material. According to the invention, the electrochemical property of the composite material is enhanced to a large degree through the compounding of the graphene, cobalt ferrite and polyaniline, the specific capacitance achieves 1318 F/g, and the specific capacitance is damped by about 5% after the composite material is circulated for 5000 circles.

The invention discloses a three-dimensional micro-nano material composed of nano CoFe2O4 and a preparation method thereof. The three-dimensional micro-nano material is of a double-hexagon flower dumbbell type opposite-connected structure and is obtained by the following steps: 1) adding tervalent iron salt and divalent cobalt salt in polyol, stirring to obtain transparent liquid, heating for reacting, and then cooling to room temperature and collecting precipitates; 2) centrifugally washing the precipitates with ethanol, and drying so as to obtain a yellow green cobalt ferrite precursor; and 3) firing the precursor so as to obtain the CoFe2O4 micro-nano structure with the double-hexagon flower dumbbell type opposite-connected structure. According to the invention, the process is simple and practicable, the distribution range of the obtain material particle is narrow, and the micro-nano material has the advantages of single dispersibility, single product phase and good reaction repeatability; and the synthesized material simultaneously has characteristics and advantages of a micro-nano structure and a nano structure.

The invention discloses a preparation method of a polyaniline/sliver-coated/cobalt ferrite composite material. The preparation method comprises the following steps: respectively weighing three substances according to a stoichiometric ratio of cobalt nitrate to ferric nitrate to citric acid of 1:2:4: preparing cobalt ferrite (CoFe2O4) by adopting a sol-gel process; carrying out chemical silver-plating onto the prepared CoFe2O4 to obtain wave-absorbing filler with excellent electromagnetic performances; and preparing PANI (Polyaniline)/Ag/CoFe2O4 composite material by using aniline monomer and Ag/CoFe2O4 as raw materials through a chemical in-situ polymerization method. The composite material is combined with the excellent electrical performance of metal single substance Ag, the good magnetic performance of CoFe2O4 as well as good processability, stability and electrical performance of the conductive high polymer polyaniline, is a good microwave-absorbing material, and has an important application value in the microwave-absorbing field. The Ag/CoFe2O4 composite filler obtained by the preparation method disclosed by the invention is combined with the excellent electrical performance of the Ag and the good magnetic performance of the CoFe2O4, and is a good electromagnetic composite material; the PANI/Ag/CoFe2O4 prepared by using the composite material as the filler has good microwave-absorbing performance.

A composition for treating dye wastewater and method of synthesizing said composition, is disclosed. The composition is a catalyst composition used for ultrasound irradiation process. The composition comprises a copper sulfide and cobalt ferrite (Cu₂S/CoFe₂O₄) nanocomposite material, and hydrogen peroxide (H₂O₂). Further, the present invention also discloses a method for treating dye wastewater using said nanocomposite catalyst composition. The composition according to the present invention, provides a novel, eco-friendly and economical method for the complete degradation of the organic dye pollutants from the industrial wastewater. Further, the sonocatalyst has enough stability, as its structure and degradation ability does not change even after multiple use. Further, the sonocatalyst could be easily separated and reused from a waste water, without any need for complex separation process.

The invention relates to a preparation method and an application of a Z-type magnetic nanocomposite MoS2/CoFe2O4 photocatalyst and aims to solve the problems that the catalyst is difficult to recover and is wasted after the existing photocatalyst degrades organic dyestuff. According to the method, CoFe2O4 magnetic nanoparticles and MoS2 nano-laminated structures are prepared with a simple solvothermal method and a simple hydrothermal method respectively, and the method has the advantages of being simple and efficient. The Z-type magnetic nanocomposite MoS2/CoFe2O4 photocatalyst is used for deeply purifying organically polluted water.

The invention relates to a ferrite/polypyrrole (PPy) magnetic nano-photocatalyst which is composed of magnetic ferrite nanoparticles with spinel structure, and polypyrrole coated on surface of the ferrite nanoparticles. The ferrite has molecular formula of MFe2O4, wherein M is Ni, Cu, Zn, Mn or Co. A preparation method of the ferrite/PPy magnetic nano-photocatalyst comprises the steps of dispersing ferrite nanoparticles and initiator in acid solution; adding pyrrole into the above system under constant temperature; reacting under thermostatic condition; performing filtration separation on resultant product with large amount of deionized water; and drying to obtain cobalt ferrite/PPy magnetic nanomaterial. The inventive photocatalyst has the advantages of high dye adsorbability, visible light response, magnetism, convenient recovery and cyclic usage.

The invention provides a nitrogen-doped carbon nano-array/cobalt ferrite material obtained by calcining a polyaniline-iron-cobalt metal organic framework, the nano material is a double-metal oxide, and has a large specific surface area, a plurality of catalytic sites, and higher catalytic efficiency. The polyaniline-iron-cobalt metal organic framework has good compatibility with various metal ions, a uniform multi-metal spinel can be easily synthesized from the polyaniline-iron-cobalt metal organic framework, the double-metal oxide and a conductive polymer are combined, so that advantages of different types of electrode materials can be combined with each other, and at the same time, nitrogen-doped carbon can be formed by polyaniline calcination, conductivity is further improved, and the defects of poor conductivity and poor stability of iron-cobalt oxides can be solved.

The invention provides a preparation method for a cobalt ferrite (CoFe2O4)-quasi-graphite carbon (SG) nano-composite (CF-SG), and belongs to the technical field of composite materials. Fe(NO3)3.9H2O, Co(NO3)2.6H2O and shaddock peel are used as raw materials, deionized water is used as a solvent, and the CoFe2O4-SG nano-composite is obtained through one-step composition by means of a hydrothermal method. The composite material is composed of the CoFe2O4 of the spinel structure and the SG, has the high adsorption activity, can be rapidly separated under the action of a magnetic field, and can achieve recycling of adsorption materials. In addition, the preparation method has the advantages that the technology is simple, the flow path is short, the cost is low, the yield is high, no any additive is adopted in the synthetic process, and environmental protection is achieved.

The invention discloses a method of treating a waste lithium battery by adopting a mechanochemistry method, selectively recycling metal lithium and meanwhile directionally preparing a cobalt-based magnetic functional material, belonging to a new technology of treating solid wastes in the field of environmental protection and comprehensive utilization of resources. The method particularly comprises five procedures of discharging, splitting, ball milling, lithium recycling and calcining. The method is characterized in that a dry ball milling mode is adopted, so that materials and an assistant generate a solid phase reaction and no waste liquid is produced; by controlling the reaction process, the metal lithium is selectively recycled, and a magnetic material is directionally synthetized from metal cobalt. The method is simple and convenient to operate, low in cost, high in recovery rate, and mild in reaction condition, the assistant is cheap and easy to get, a prepared cobalt ferrite is excellent in magnetism, strong acids and strong oxidizers are not used all the way, and the method is a green and environment-friendly waste lithium battery recycling method.