98 results about "Ferrite nanoparticles" patented technology

The present invention relates to a poly(organophosphazene)-superparamagnetic nanoparticle complex including a biodegradable and thermosensitive poly(organophosphazene) and a iron oxide (Fe₃O₄, Magnetite)-series ferrite superparamagnetic nanoparticle, a preparation method, and uses of carrying a physiologically-active material, a bio-material and a biomaterial for cancer hyperthermia. The iron oxide is used as a MRI contrast agent for T-₂ and T₂* weighted image, and the poly(organophosphazene) shows a sol-to-gel behavior depending upon the temperature change. The complex is a bound-type where the superparamagnetic ferrite nanoparticle is bonded to phosphazene-based polymer via hydrophobic binding, and a mixed-type where the superparamagnetic ferrite nanoparticle is physically mixed with the phosphazene-based polymer.

The invention discloses a graphene/nano ferrite based water electromagnetic shielding paint and a preparation method thereof. Ferrite nanoparticles are loaded on the surface of graphene to prepare a graphene/ferrite nanocomposite with the electrical conductivity of the graphene and the good magnetic property of the nano ferrite, and then the nanocomposite is combined with a water film-forming resin and other auxiliaries to prepare the green and environment-friendly water electromagnetic shielding paint. The preparation method has the characteristics of being simple to operate, high in practicability, free of hazardous substance, capable of making electromagnetic shielding paints suitable for different frequencies and occasions, good in shielding effect, and the like; the prepared graphene/nano ferrite based water electromagnetic shielding paint has excellent electromagnetic shielding performance, and therefore has good application prospect in the field of electromagnetic shielding paints.

A superparamagnetism mesoporous silicon dioxide composite ball of the present invention and manufacture method thereof belong to nucleocapsid type technology field of magnetic nano particle. The shape of the composite ball is global; inner core being made of magnetic ferrite nano particle cluster, shell coating layer being made of mesoporous silicon dioxide; quality ratio of magnetic ferrite nano particle in particulate being 40-80%. Method of manufacturing has that producing magnetic ferrite nano particle is by using coprecipitation method; executing surface modification by adding oleic acid stirring; ultrasonic forming oil-in-water emulsion in the mix solution of ethyl orthosilicate and cyclohexane, cetyl trimethyl ammonium bromide as surfactant; ethyl orthosilicate hydrolytic condensation forming mesoporous silicon dioxide coating layer by adding ammonia spirit; finally taking off molding plate and getting products. Product of the invention has bigger specific surface area and stronger magnetic separation capacity, and has good dispersancy in water, and is further functionalization after being decorated at surface. The method of the present invention has simple process, and lower equipment requirement.

The invention relates to a sulfonylation graphene oxide magnetic adsorbent, and a preparation method and application thereof. The adsorbent uses graphene oxide nanosheet as a substrate; the substrate surface is loaded with magnetic ferrite nanoparticles, and contains a large amount of sulfonic acid. The method comprises the following specific steps: first subjecting a graphite powder to pre-oxidation and deep oxidation, and conducting ultrasonic separation to obtain a graphene oxide solution; then adding a mixed solution of iron ions and ferrous ions; rapidly adding ammonia solution while stirring to obtain magnetic graphene oxide; and finally grafting aminobenzene sulfonic acid to magnetic graphene oxide matrix, washing and determining a constant volume to obtain a final product. The product has good adsorption effect on the heavy metals, copper and cadmium, and organic aniline. The product has the advantages of low cost, large specific surface area, high adsorption capacity and easy separation and recovery. The invention can be used for treating wastewater from smelting factory, electronics factory, chemical plant and electroplating plant.

A magnetic core-shell microparticle with strong response power to magnetic field is composed of SiO2 as shell and 20-1000 nanometre-class magnetic ferrite particles with super-paramagnetism. Its preparing process includes such steps as preparing the said ferrite particles by the deposition method, dispersing them in the aqueous solution of water-soluble inorganic salt containing SiO2, stirring, and hydrolysis reaction of ethyl n-silicate for coating SiO2 again.

The invention discloses a ferrite/graphene composite adsorbent and preparation and using methods thereof, and belongs to the technical field of adsorbents. The ferrite MFe2O4/graphene composite adsorbent is prepared by taking hexamethylenetetramine as a precipitator and a reducing agent and decomposing the hexamethylenetetramine under a hydrothermal condition to generate alkaline and reducing substances by one step. M is Mn, Ni, Co and Zn; the mass percentage of the ferrite is 40-70 percent; ferrite nano particles are dispersed on the sheet type graphene surface; the particle sizes of the ferrite nano particles are 5-30 nanometers; and the specific surface area of the ferrite/graphene composite adsorbent is 60-300 m<2>/g. The ferrite/graphene composite adsorbent has the advantages that the shortcomings of high reaction temperature, non-uniform reactants and low product structure and composition uniformity of the conventional ferrite composite metal oxide prepared by solid phase reaction are overcome; an effect of adsorbing heavy metal ions Cr<6+>, Pb<2+>, Cu<2+>, Cd<2+> and Hg<2+> in water is achieved; and a wide application prospect is realized.

The invention relates to the field of nanometer drug carriers, and concretely relates to an asymmetric magnetic mesoporous silica rod supporting chemotherapeutic and gene drugs and application thereof to tumor diagnosis and treatment. The asymmetric magnetic mesoporous silica rod is prepared by employing spherical magnetic ferrite nanoparticles and ethyl orthosilicate through a sol-gel method, and the asymmetric magnetic mesoporous silica rod is subjected to surface functionalization modification, and is successively loaded with a chemotherapeutic drug, coated by a positive high-molecular polymer and loaded with a gene drug, so that a target product is obtained. The chemotherapeutic drug is connected with the silica rod through functionalization of the mesoporous surface, and the silica rod is endowed with the pH-responsive drug release characteristic, also the biocompatibility of the composite material is increased and the in-vivo cycling time is prolonged, and gene is supported in an electrostatic adsorption mode. The composite material is injected into a living body via an intravenous route, the characteristics of nanoparticle in-vivo passive targeting, gene guiding and pH-responsive drug release of the composite material are utilized, also the cooperativity of the multidrug resistant gene and the chemotherapeutic drug is utilized, and in-vitro magnetic targeting, NMR imaging and other technologies are applied to diagnosis and treatment of malignant tumors.

The invention belongs to the field of nano adsorption materials and in particular relates to a high-efficiency superparamagnetic ferrite nano arsenic adsorbent and a preparation process thereof. The prepared nano ferrite can well remove harmful ions (such as arsenic) from water and has strong magnetic recovery capacity, so that the problems of excessive harmful ions in the water and incapability of recovery of the adsorbent at present are solved. The adsorbent consists of superparamagnetic spinel ferrite phase nanoparticles and is nanopowder with the grain size of 3 to 8 nm, wherein the specific surface area is 100 to 500 m<2>/g. According to the process, pure crystallized nano ferrite powder is prepared by using anhydrous metal chloride, absolute ethanol and sodium hydroxide as reaction precursors and performing solvent thermal reaction. The prepared superparamagnetic ferrite nanoparticles are high in purity, small in grain size, high in specific surface area and high in hydrophilicity and more new selectable materials are provided for reducing the harmful ion (such as arsenic) content of water.

The invention discloses Mn element and Zn element-doped super-paramagnetic ferrite nanoparticles and a preparation method thereof. Manganese element is added or manganese element and zinc element are simultaneously added into a face-centered cubic crystal structure of ferriferrous oxide nanoparticles by using a method of decomposing metal precursor compound at a high temperature; the magnetic performance of the prepared super-paramagnetic nanoparticles is improved by changing the doping amount and the distribution of the metal element; and primarily, the saturation magnetization is improved. The preparation method specifically comprises the following steps of: mixing acetylacetones of Fe and Mn as well as Zn with 1,2-hexadecanol; performing high-temperature decomposition in high-boiling-point solvent by taking oleic acid and oleylamine as surfactants; or performing high-temperature decomposition on composite oleate of Fe, Mn and Zn by taking the oleic acid as the surfactant; heating and preserving heat in stages in argon or nitrogen protective atmosphere to guarantee growth of nanoparticle nuclear; and cooling to room temperature after reaction is finished and settling and centrifuging to finally obtain the super-paramagnetic ferrite nanoparticles which are uniformly dispersed in normal hexane solution.

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 discloses a preparation method for silicone-oil-based magnetic liquid. The preparation method for the silicone-oil-based magnetic liquid is mainly characterized in that 1, Fe3O4 is prepared with a coprecipitation method, and through comparison of physicochemical properties of Fe3O4, a ferric oxide crystal with good crystal morphology and magnetic performance is used for following decoration; 2, the surface of the ferric oxide crystal is coated with a SiO2 shell through a Stober method; 3, ferrite nanoparticles of a shell-core structure are obtained through the Fe3O4 magnetic particles covered by SiO2 and spread in silicone oil base liquid, and then the silicone-oil-based magnetic liquid is obtained. The obtained magnetic liquid can resist to high temperature and is high in saturation magnetization intensity, good in seal performance, high in pressure resisting capacity and long in sealing life.

The invention relates to novel black or brown magnetic falsification-resistant offset printing ink comprising the following components: magnetic nano powder, binders, solvents, lubricating agents, defoaming agents, levelling agents, drying agents, mineral oil, etc. The offset printing ink is characterized in that the used magnetic powder body is formed by one or more of self-made ferrite nanoparticles (with mean grain size between 10nm and 200nm) with chemical formula of MFe2O4 (M=Fe, Co, Ni, Cu, Mg, Zn, Mn and other bivalent cations or combination thereof) or AxB1-XFe12O19 (A=Fe, Co, Ni, Cu, Mg, Zn, Mn and other bivalent cations or combination thereof; B=Ba, Sr, Pr or combination thereof) or nano-scale iron, cobalt and nickel or alloy powder thereof. The labels printed by the magnetic printing ink present black or brown characteristic and simultaneously have magnetic falsification-resistance function. The printing ink has diversified falsification-resistance functions and high technical content, is difficult to copy and can be used for falsification-resistant printing of outer packages of commodities, valuable securities, labels, dockets, etc.

The invention discloses a preparation method and application of a graphene/cobalt-nickel-manganese ferrite nano-composite material. The preparation method comprises: adding a solution containing an iron source, a cobalt source, a nickel source and a manganese source into a dispersion containing graphene oxide drop by drop to obtain a mixed solution, adjusting pH of the mixed solution to greater than or equal to 8, adding a reducing agent into the mixed solution to obtain a precursor solution, transferring the precursor solution into a reactor, and carrying out microwave synthesis to obtain thegraphene/cobalt-nickel-manganese ferrite nano-composite material. The graphene/cobalt-nickel-manganese ferrite nano-composite material is composed of layered graphene and spherical cobalt-nickel-manganese ferrite nanoparticles. The spherical cobalt-nickel-manganese ferrite nanoparticles are uniformly dispersed on the layered graphene surface and between the layers. The graphene/cobalt-nickel-manganese ferrite nano-composite material has the characteristics of strong absorption intensity, effective absorption frequency bandwidth, thin thickness and light weight.

The invention relates to a preparation method and application of magnetic aminated graphene oxide. The preparation method comprises the steps of firstly loading ferrite nanoparticles on a graphene oxide nanosheet so as to prepare magnetic graphene oxide, and grafting diethylenetriamine to the surface of the magnetic graphene oxide so as to prepare the magnetic aminated graphene oxide, wherein the prepared magnetic aminated graphene oxide is easily applied to solid-liquid separation and is easy to recycle. According to the magnetic aminated graphene oxide prepared by virtue of the preparation method, bivalent copper ions in water can be effectively removed, the adsorption property of the magnetic aminated graphene oxide is influenced by the pH value of a solution and back-ground electrolyte. The magnetic aminated graphene oxide can be applied to the treatment of copper-containing wastewater discharged by electroplate factories, smelting plants, electronic equipment factories and the like.

The invention discloses a carbon nanotube/chitosan/magnetic ferrite nanoparticle composite material. A preparation method of the material comprises the following steps of: coating chitosan polymer and magnetic ferrite nanoparticles on multi-wall carbon nanotubes from inside to outside in turn; modifying the surfaces of the carbon nanotubes by coating the chitosan; and depositing the magnetic ferrite nanoparticles on the carbon nanotubes in situ by a hydrothermal method. The material prepared by the method has higher saturation magnetization rate and T2 relaxation coefficient, and is a good magnetic resonance imaging contrast medium. In the invention, concentrated acid oxidation treatment is not required to be performed on the carbon nanotubes in advance, so that the structural integrity of the carbon nanotubes is protected; and the preparation method has the advantages of readily available raw materials, low cost and the like, is easy to operate and is suitable for industrial production.

The invention relates to a composite material used for embedding ferrite nanoparticles into antiferromagnetic oxide base and a preparation method thereof. The preparation method comprises the following steps: (1) mixing solution of metal ions is prepared; (2) ammonium hydrogencarbonate aqueous solution is added into the mixing solution of the metal ions so as to form sediment; (3) the obtained sediment is filtered, washed and dried until dry powder is obtained; (4) the obtained powder is sintered in the air at high temperature, thus forming the composite material used for embedding the ferrite nanoparticles into the antiferromagnetic oxide base. The composite material used for embedding the ferrite nanoparticles into the antiferromagnetic oxide base prepared by the method has magnetic exchange bias effect.

The invention provides a rapid preparation method of core-shell spherical magnetic mesoporous silica nanocomposites. The invention also provides an application of the core-shell spherical magnetic mesoporous silica nanocomposites in diagnosis and treatment of tumors. According to the preparation method, spherical magnetic ferrite nanoparticles are prepared by an alkali hydrolysis method; and by using the spherical magnetic ferrite nanoparticles as seed particles and by the utilization of self-assembly behavior of a surfactant in an aqueous solution and an inorganic silicon source, the surface of the magnetic ferrite nanoparticles is rapidly coated with a layer of mesostructured silica nanocomposites so as to obtain the core-shell spherical magnetic mesoporous silica nanocomposites. The method is time-saving and reaction condition is pure water phase. By the method, a lot of the core-shell spherical magnetic mesoporous silica nanocomposites can be prepared within a short time.

The invention belongs to the technical field of magnetic nanomaterial preparation, and relates to the successful preparation of nanoparticles with superparamagnetic properties. The product has the characteristics of high crystallinity, uniform particles, strong magnetic response, and good photocatalytic activity to methylene blue. The raw materials are cheap and easy to obtain, the synthesis process is simple, and it is suitable for large-scale commercial production. These magnetic nanoparticles and their composite materials are widely used in biomedicine (protein adsorption, DNA separation, disease diagnosis and treatment, drug targeted delivery, nuclear magnetic resonance imaging (MRI)) chemical catalysis and coating materials, absorbing materials, electrode materials, There are a wide range of applications in many fields such as electrocatalysis and sewage treatment.

A composite material can include a grain component and a nanostructured grain boundary component. The nanostructured grain boundary component can be insulating and magnetic, so as to provide greater continuity of magnetization of the composite material. The grain component can have an average grain size of about 0.5-50 micrometers. The grain boundary component can have an average grain size of about 1-100 nanometers. The nanostructured magnetic grain boundary material has a magnetic flux density of at least about 250 mT. The grain component can comprise MnZn ferrite particles. The nanostructured grain boundary component can comprise NiZn ferrite nanoparticles. Core components and systems thereof can be manufactured from the composite material.

Provided is a new magnetic material with high magnetic stability, as well as a manufacturing method therefor, said magnetic material having a higher saturation magnetization than ferrite-based magnetic materials, and having a higher electrical resistivity than existing metal-based magnetic materials, thus solving problems such as that of eddy current loss. Mn-ferrite nanoparticles obtained through wet synthesis are reduced within hydrogen, and grains are allowed to grow while simultaneously using a phase separation phenomenon due to a disproportionation reaction to produce a magnetic material powder in which an α-(Fe, Mn) phase and a Mn-enriched phase are nano-dispersed. This powder is then sintered to produce a solid magnetic material.

Provided is a new magnetic material with high magnetic stability, as well as a manufacturing method therefor, said magnetic material having a higher saturation magnetization than ferrite-based magnetic materials, and having a higher electrical resistivity than existing metal-based magnetic materials, thus solving problems such as that of eddy current loss. Ti-ferrite nanoparticles obtained through wet synthesis are reduced within hydrogen, and grains are allowed to grow while simultaneously using a phase separation phenomenon due to a disproportionation reaction to produce a magnetic material powder in which an α-(Fe, Ti) phase and a Ti-enriched phase are nano-dispersed. This powder is then sintered to produce a solid magnetic material.