121 results about "Triiron Tetraoxide" patented technology

The invention belongs to the technical field of catalysis materials, and discloses a photo-Fenton catalyst Fe3O4 / rGO / TiO2, a preparation method and applications thereof. The preparation method comprises: adding aminated nanometer triiron tetraoxide to isopropanol, carrying out ultrasonic dispersing, adding a graphene oxide aqueous solution in a dropwise manner, carrying out a reaction for 2-3 h under a mechanical stirring condition to obtain a Fe3O4 / GO composite material, dispersing the Fe3O4 / GO composite material in isopropanol, adding tetrabutyl titanate in a dropwise manner under a stirring condition, carrying out a reaction for 30-60 min, adding distilled water, uniformly stirring and mixing, and carrying out a hydrothermal reaction on the obtained mixed solution at a temperature of 180-200 DEG C to obtain the photo-Fenton catalyst Fe3O4 / rGO / TiO2. According to the present invention, the obtained photo-Fenton catalyst Fe3O4 / rGO / TiO2 has advantages of high catalysis performance, stable structure, no pollution of the degradation product, and has good application prospects in treatment of antibiotic wastewater.

The invention relates to the technical field of magnetic metal organic framework materials, in particular to a preparation method and application of Fe3O4 / MIL-101(Cr). The method includes the steps of preparing MIL-101(Cr) material through a hydrothermal method to serve as a template, and generating Fe3O4 particles in situ in holes of MIL-101(Cr) through a reduction co-precipitation method under the ultrasonic conduction and in a nitrogen protection state. The Fe3O4 / MIL-101(Cr) composite obtained through the method is strong in magnetism, large in surface area, shortened in synthesis time, controllable in synthesis condition, novel in synthesis method, simple and easy to repeat, stable and controllable in prepared material quality, and capable of being synthesized in batches. The Fe3O4 / MIL-101(Cr) composite is good in effect and can be repeatedly used six times or more when used for adsorbing and removing acid dyes in environmental water.

The present invention relates to new material, and is one kind of carbon fiber reinforced friction resistance material suitable for producing automobile and train brake disc and its preparation process. The carbon fiber reinforced friction resistance material is produced with reinforcing fiber, base resin and friction performance regulator, the reinforcing fiber is the mixture of carbon fiber, metal fiber and inorganic mineral fiber; the base resin is water latex modified phenolic resin; and the friction performance regulator consists of at least two of barium sulfate, ionic oxide, triiron tetrachloride, iron trichloride, magnesia and silica. The preparation process includes the steps of mixing material, pre-stoving, pressing and post-treatment. The carbon fiber reinforced friction resistance material has excellent friction resistance performance and the preparation process has no pollution.

The invention provides a preparation method of polyamine compound-modified magnetic chitosan and an application thereof. The preparation method comprises the following steps: firstly swelling chitosan with a 2% acetic acid solution, then connecting triethylene tetramine to the chitosan molecules by epoxy chloropropane, performing carboxymethylation of the above product by chloroacetic acid, and finally introducing magnetic ferroferric oxide into the triethylene tetramine-grafted chitosan molecules by using N,N'-dicyclohexyl carbimide with N,N-dimethyl formamide as a solvent, so as to obtain a target adsorbent. The adsorbent of the invention is mainly used for adsorption treatment of heavy metal ion-polluted waste water, not only can be used for adsorption recovery of single heavy metal ion, but also can be used for adsorption treatment of waste water polluted by a plurality of heavy metal ions, has the advantages of good adsorption effect, no secondary pollution, easy separation, recyclability, cheap and easily available raw materials, and the like, and is a potential heavy metal waste water treating agent.

The invention relates to a preparation method of a folic acid coupled gold nano-rod / polypyrrole / ferroferric oxide multifunctional composite nano diagnosis and treatment agent. The preparation method comprises the following steps: by adopting composite nanoparticles consisting of gold nano-rods, polypyrrole and ferroferric oxide as a substrate, modifying the surfaces of the composite nanoparticles by using polycationic electrolyte chitosan and polyanionic electrolyte sodium alginate respectively by virtue of a layer-by-layer self-assembly process to ensure that the surfaces of the nanoparticles contain amino groups, and then connecting with carboxy groups of folic acid. The prepared multifunctional composite nano diagnosis and treatment agent disclosed by the invention has the advantages of high photo-thermal conversion efficiency, good biocompatibility, active tumor targeting performance, strong cancer cell killing ability, significant imaging effect, a function of being controlled for a long time, and the like, and can be applied to treatment, pathological magnetic resonance imaging analysis and medical diagnosis of X-ray computer tomography and ultrasonic imaging of tumors or cancers of human bodies or other mammals.

The present invention relates to a preparation method of a magnetic superhydrophobic ethylcellulose sponge for oil-water separation. The preparation method specifically comprises: preparing silane hydrophobically modified ethyl cellulose, introducing the silane hydrophobically modified ethyl cellulose adopted as a matrix into oleic acid-coated triiron tetraoxide magnetic nanoparticles prepared through a co-precipitation method, and obtaining a magnetic superhydrophobic three-dimensional porous material capable of efficiently performing oil-water separation through a pore forming agent occupation method. According to the present invention, the ethyl cellulose is firstly used as the oil-water separation material, such that the preparation method has advantages of economy, high efficiency, simple preparation process, wide raw material source, green environmental protection, and durability; the prepared superhydrophobic porous sponge has advantages of excellent oil absorption, excellent stability, excellent recyclability, excellent biodegradability, and the like; and the preparation method further has characteristics of simpleness, easy performing, industrial production of the raw materials, and good promotion application value.

The invention discloses a preparation method of doxorubicin hydrochloride magnetic nanoparticles. The preparation method comprises the following steps: (1) dissolving nano block polymer polyethylene glycol-polylactic acid in dimethyl formamide to prepare a solution A; (2) dissolving doxorubicin hydrochloride in dimethyl formamide to prepare a solution B; (3) adding triethylamine into the solution B, and performing the deionization ultrasonic dissolving on the doxorubicin hydrochloride; (4) dissolving ferroferric oxide powder in tetrahydrofuran, and ultrasonically dispersing to obtain a solution C; (5) dropwise adding the deionized solution B into the solution A under a stirring condition; (6) stirring and uniformly mixing the doxorubicin hydrochloride and nano blocks, and volatilizing organic solvent to obtain medicine carrying micelle; (7) dropwise adding the solution C into the medicine carrying nano micelle obtained in the step (6), and uniformly stirring; (8) dialyzing to obtain magnetic medicine carrying nano micelle; and (9) adding a freeze drying protective agent into the nano micelle to obtain the magnetic medicine carrying nanoparticles. The method is simple in operation procedures and easy in operation.

Calcium deficiency and low absorptivity of calcium are known as global problems, and it is confirmed that phosphorylated peptides are capable of promoting absorption of calcium by human body effectively, so that research on high-efficient and rapid enrichment method of phosphopeptides is of significant importance. Separation and purification of target substances by taking magnetic nanoparticles as adsorption carriers are emerging technologies. According to the emerging technologies, the magnetic nanoparticles are subjected to surface modification so as to realized separation and purification of the target substances, and rapid separation of the target substances from complex systems can be realized in the presence of an applied magnetic field. Compared with traditional methods, magnetic separation technology is fast, is simple in operation, and high in efficiency and recovery rate. The invention firstly provides a preparation method of metallic oxide magnetic nanoparticles, and the obtained zirconium dioxide and ferriferrous oxide magnetic nanoparticles are used for enrichment of phosphopeptides. The zirconium dioxide and ferriferrous oxide magnetic nanoparticles possess superparamagnetism and excellent water dispersibility, and show high specificity on adsorption of phosphopeptides. Enrichment effects on phosphopeptides of the method based on the metallic oxide magnetic nanoparticles are obviously better than that of the conventional methods.

The invention provides a preparation method of an oil-soluble Fe3O4 / modified graphene oxide composite material. The method includes steps of: a) under alkaline condition, mixing a graphene oxide watersolution and a water solution containing Fe<3+> and Fe<2+>, and performing a heating reaction to obtain a Fe3O4 / modified graphene oxide composite material; B) performing a mixing reaction to the Fe3O4 / modified graphene oxide composite material with alkyl amine to obtain the oil-soluble Fe3O4 / modified graphene oxide composite material, wherein the alkyl amine is selected from lauryl amine, tridecylamine, tetradecylamine, cetylamine, octadecylamine, or diisotridecylamine. In the invention, firstly, through chemical coprecipitation to the Fe<3+> and Fe<2+> and graphene oxide, water-soluble Fe3O4 / graphene oxide is obtained; then through self-assembling to the Fe3O4 / modified graphene oxide with specific alkyl amine, the oil-soluble Fe3O4 / modified graphene oxide composite material is produced.

The invention discloses resin-based metal copper anticorrosion coating and a preparation method thereof. The coating comprises, by weight, 0.2-0.4 part of p-tert-amyl phenol, 1-2 parts of sodium lauroyl sarcosine, 1-2 parts of amino trimethylene phosphonic acid, 10-14 parts of vinyl trimethoxy silane, 200-300 parts of 1.8-2g / l citric acid solution, 13-17 parts of silane coupling agent KBM5103, 100-110 parts of tetraethylortho silicate, 30-37 parts of hexafluorobutyl acrylate, 0.1-014 part of azodiisobutyronitrile, 5-7 parts of 20-25% ammonium water, 4-5 parts of ferroferric oxide, 2-3 parts of perfluorosulfonate resin, 1-2 parts of borax, 0.2-0.5 part of beta-hydroxyl alkyl amide and 3-4 parts of sorbitol monoleate. The resin-based metal copper anticorrosion coating can form various hybridization coating surfaces of different structures, and the different-structured coating surfaces combine with exposed low-surface-energy ethylene groups to allow the coating to have a super-hydrophobic property.

The invention provides a petal-shaped ferroferric oxide-based composite wave-absorbing agent, a preparation method thereof and a wave-absorbing material. The composite wave-absorbing agent is composedof graphene, petal-shaped ferroferric oxide and polyaniline, the petal-shaped ferroferric oxide is distributed on the graphene, and the polyaniline coats the surfaces of the graphene and the petal-shaped ferroferric oxide and the contact interface of the graphene and the petal-shaped ferroferric oxide. According to the preparation method, a reflux method and a chemical coprecipitation method areutilized, firstly rGO / iron alkoxide is prepared by taking tetrabutylammonium bromide as a structure directing agent for preparing petal-shaped Fe3O4; then organic matters such as a structure-directingagent and the like in the rGO / iron alkoxide and structural water are removed by utilizing a high-temperature calcination method to obtain rGO / f-Fe3O4; and finally, the rGO / f-Fe3O4 is coated by utilizing a chemical oxidative polymerization method and aniline in-situ polymerization to prepare the rGO / f-Fe3O4 coated PANI composite wave absorbing agent. The wave-absorbing agent prepared by the methodhas stronger maximum wave-absorbing strength and wider effective absorption frequency band.

The invention relates to a preparation method of a catalyst for photocatalytically decomposing a toxic and hazardous gas PH3. According to the preparation method, low-cost natural halloysite nano-tubes (HNTs) are used as a carrier, tetrabutyl titanate, nickel chloride, ferric chloride and ferrous sulfate are used as precursors, nano-titania (TiO2) is synthesized on the surface of the carrier in anin-situ manner, and ammoniation, impregnation, drying, calcination, hydrogen reduction and other steps are performed to generate the metal nickel (Ni) and triiron tetraoxide (Fe3O4) catalytically active center on the surface of the composite carrier. According to the present invention, the reactions of the preparation method are easily performed, the uniformity at the molecular level can be obtained within a short time, the process is simple, and the efficiency of the catalytic decomposition of PH3 can be enhanced by introducing the photocatalytic material.

The invention relates to a preparation method for a PEI-coated bimodal contrast agent, i.e., a ferriferrous oxide-gadolinium hydroxide magnetic nanoparticle. The preparation method comprises the following steps: (1) dissolving an Fe source in ultrapure water, then adding NH3.H2O, carrying out stirring in the air to realize oxidation, then adding an aqueous solution of polyethylene imine (PEI) and an aqueous solution of Gd(NO3)3 and carrying out natural cooling to room temperature after completion of a reaction so as to obtain Fe3O4-Gd(OH)3-PEI; and (2) subjecting Fe3O4-Gd(OH)3-PEI and methoxypolyethylene glycol carboxylic acid to pegylation. The preparation method provided by the invention has the advantages of simple process, mild reaction conditions and easy operation and separation; the prepared ferriferrous oxide-gadolinium hydroxide magnetic nanoparticle (Fe3O4-Gd(OH)3-PEI-PEG) has good biocompatibility, good relaxation effects at T1 and T2 and a latent application value in the field of MRI imaging diagnosis.

The invention discloses a composite flying dust inhibitor and a preparation method thereof. The composite flying dust inhibitor is prepared from the following raw materials: a urease preparation, sodium alginate, urea, calcium chloride, magnesia, ethyl orthosilicate, triiron tetraoxide powder and the like. The inhibitor provided by the invention adopts a granular structure, an outer layer is coated with the urease preparation, and urease is separated from internal components by the modified sodium alginate. The inhibitor is diluted in water when in use, and the urease accelerates the hydrolysis of urea to react with the calcium chloride to generate calcium carbonate. Flying dust particles are bonded together to form large particles by the bonding performance. Meanwhile, through the large area adsorption of the modified magnesia, the fast and efficient inhibition of flying dust is effectively ensured. Compared with a traditional dust inhibitor, the dust inhibition effect is greatly improved, and the service cost is greatly decreased. The composite flying dust inhibitor and the preparation method thereof are suitable for being generally popularized and used.

The invention relates to the technical field of soil remediation materials, and discloses a magnetic carbon composite material for remedying heavy metal contaminated soils and a preparation method thereof. The preparation method includes the steps that bivalent ferric salt and trivalent ferric salt are mixed, then biomass charcoal and water are added and mixed evenly, the bivalent ferric salt andthe trivalent ferric salt are adsorbed by the biomass charcoal, and liquid is filtered out naturally; the biochar that adsorbs bivalent ferric salt and trivalent ferric salt is obtained, then ammoniawater is added, a reaction is carried out to generate ferroferric oxide, and washing with water is carried out to obtain a magnetic modified biochar material; and the magnetic modified biochar material and beta cyclodextrin modified starch are uniformly stirred and mixed, and granulating is carried out to form the magnetic soil remediation material. The problems that an existing magnetic materialis complex in preparation process and poor in acid resistance in soil remediation application are solved. The beta cyclodextrin modified starch is compounded with the magnetic modified biochar material, so that the adsorption capacity of heavy metal ions in soil can be improved, the remediation efficiency of the soil is improved, and meanwhile, the magnetic soil remediation material has relativelygood acid resistance, so that the magnetic soil remediation material can be recycled after heavy metals are removed by dilute acid washing after being recycled.

The invention provides a method for preparing carbon / calcium phosphate / ferroferric oxide composite structured nano particles, and application of the nano particles. The method comprises the following steps: by taking calcium hydroxide, polyacrylic acid, isopropanol, ferrous chloride and diammonium phosphate as raw materials, performing calcining, mixing, drying and the like, thereby obtaining the carbon / calcium phosphate / ferroferric oxide composite structured nano particles by using the simple method. The prepared product is uniform in particle size, high in photo-thermal conversion efficiency and good in biocompatibility, and has very good application prospects in fields such as photo-thermal treatment, medicine conveying and biological imaging.

The invention relates to the technical field of catalysts, and more particularly to a magnetic catalyst, a preparation method thereof, and a method for preparing furfuryl alcohol. The preparation method of the magnetic catalyst comprises the following steps: treating carbon nanotubes, namely treating the carbon nanotube in an acid agent to obtain acid-treated carbon nanotubes; and carrying out reaction, namely adding the acid-treated carbon nanotubes to an aqueous solution of ferric trichloride, adjusting the pH value, then adding an aqueous solution of ruthenium trichloride thereto, and adding hydrazine hydrate to react under a stirring condition to obtain the magnetic catalyst loaded with ruthenium and triiron tetraoxide. A magnetic catalyst with ruthenium and triiron tetraoxide loaded on carbon nanotubes can be obtained by the preparation method disclosed in the invention, which is high in catalytic activity and selectivity and good in reusability without causing environmental pollution.

Provided are a friction material composition, friction material, and friction member that have excellent fade resistance and abrasion resistance at high temperatures despite not containing copper which has a high environmental burden or containing 0.5 mass% or less of copper. This friction material composition is configured to be a friction material composition that includes a binding agent, an organic filling material, an inorganic filling material, and a fiber substrate, does not include copper as an element in the friction material composition or contains 0.5 mass% or less of copper, and contains one or more types of inorganic filling material selected from -alumina having an average particle size of 10nm to 50 [mu]m, dolomite having an average particle size of 1-20 [mu]m, calcium carbonate having an average particle size of 1-20 [mu]m, magnesium carbonate having an average particle size of 1-20 [mu]m, manganese dioxide having an average particle size of 1-20 [mu]m, zinc oxide having an average particle size of 10 nm to 1 [mu]m, triiron tetraoxide having an average particle size of 1.0 [mu]m or less, cerium oxide having an average particle size of 0.5-5 [mu]m, and zirconia having an average particle size of 5-50 nm.

The present invention discloses a triiron tetraoxide / polypyrrole / polyaniline nanometer complex and a preparation method thereof, wherein the triiron tetraoxide / polypyrrole / polyaniline nanometer complex comprises a triiron tetraoxide core layer, a polypyrrole layer wrapped around the periphery of the triiron tetraoxide core layer, and a polyaniline layer wrapped around the periphery of the polypyrrole layer. According to the present invention, the triiron tetraoxide (Fe3O4) / polypyrrole (PPy) / polyaniline (PANI) nanometer complex has excellent microwave absorbing ability, and is superior to the existing similar complexes in the prior art; and the large-scale electric conduction network is established in the system by introducing the multilayer electric conduction polymer so as to substantially reduce the resistivity, and the interfacial polarization is introduced through the wrapping between different mediums so as to improve the impedance matching, such that the wave absorbing effect of the system is substantially enhanced.

The invention provides a preparation method and application of a Pd-Fe / Fe3O4 material. According to the preparation method of the Pd-Fe / Fe3O4 material, palladium chloride solid insoluble in water is dissolved in a ferric chloride or ferrous chloride solution, palladium ions and iron ions share Cl<-> to form a palladium-iron complex, the palladium-iron complex is adsorbed on a ferroferric oxide carrier after the carrier is added, and then the Pd-Fe / Fe3O4 material is formed through reduction of sodium borohydride. According to the invention, the metals Pd and Fe in the Pd-Fe / Fe3O4 material are tightly combined, Pd distribution is uniform, nitrogen selectivity is high in the reaction process of reducing and removing nitrite, and ammonia nitrogen selectivity is low.

The invention discloses a magnetic super-hydrophobic polystyrene-based porous material preparation method, which comprises: carrying out a polymerization reaction on a styrene monomer, an epoxy group-containing alkene monomer, amino-modified Fe4O3 and a cross-linking agent at 40-80 DEG C for 4-24 h under the action of an initiator, water and an emulsifier to obtain the magnetic super-hydrophobic polystyrene-based porous material, wherein the cross-linking agent is one elected from ethylene glycol dimethacrylate, divinyl benzene, triallyl isocyanurate, pentaerythritol triacrylate and trimethylolpropane triacrylate, and the epoxy group-containing alkene monomer is one selected from glycidyl methacrylate, glycidyl acrylate and glycidyl stearate. According to the invention, the prepared magnetic super-hydrophobic polystyrene-based porous material has super-hydrophobic and magnetic response, can be used for oil-water separation in food industry, chemical industry and petroleum industry, andcan perform automatic oil-water separation under magnetic driving.

The invention discloses a flocculating agent for sewage treatment. The flocculating agent comprises the following components in parts by weight: 30-50 parts of sodium polyamide xanthogenate, 15-20 parts of starch phosphate, 10-15 parts of chitosan, 5-10 parts of acrylamide, 20-30 parts of an initiator, 5-10 parts of iron sulfate, 10-15 parts of nanometer triiron tetraoxide, 20-30 parts of nanometer ferrous chloride, and 5-10 parts of a modifier; the modifier comprises the following components in parts by weight: 30-40 parts of chloroacetic acid, 20-30 parts of a cationic etherifying agent, 15-30 parts of polyepichlorohydrin-amine, and 5-10 parts of graphene. The flocculating agent for sewage treatment has excellent environmentally friendliness, most parts of the agent is biodegradable withless secondary pollution, and usage efficiency of the flocculating agent is improved. An experiment shows that the rate of deturbidity of sewage reaches 99% or above.

The invention relates to a functional material for preparing multifunctional healthy running water and a manufacturing method thereof. Composed of component A and component B, component A is composed of tourmaline, ferric oxide, zinc, copper, magnesium, iron, manganese powder and adhesive auxiliary materials, and is made by low-temperature tableting by special equipment ; Component B is a complex ion element, which is composed of medical stone, wood fish stone, fine wine jade, sepiolite, biotite, volcanic slag, calcium sulfite and clay, and is formed by sintering at high temperature; the preparation of component A : The materials are weighed in proportion, after mixing, heating, cooling, and ball milling to pulverize into micron-sized powders; adding binder to the mixed powder after ball milling and mixing; forming flakes with a punching machine; the prepared black The slices are sent to the heating furnace again to maintain a constant temperature; after cooling, they are packaged for later use. Preparation of component B: Weigh the materials according to the proportion and mix them one by one evenly, add the binder and mix them into agglomerates; inject the agglomerates into the tablet press machine to make sheets, and sinter them in a special sintering furnace after drying. Get the desired product. The water quality after being treated by the multi-functional healthy living water material prepared by the present invention has no toxic and harmful substances to the human body, and has no peculiar smell and good taste; the water body has moderate hardness and contains minerals and trace elements needed by the human body; the water body is weakly alkaline Nature, small molecular group water, the oxidation-reduction potential of water is reduced to a negative value at -200 ~ -550MV, and the nutritional and physiological functions of the water body are strong.

The invention discloses a composite volcanic rock absorbent which is characterized in that the absorbent is prepared from the following raw materials, by weight: 8-15 parts of calcium carbonate fiber, 6-8 parts of iron tetroxide magnetic powder, 20-40 parts of tetrabutyl titanate, 3-5 parts of silica sol, 6-8 parts of calcium aluminate, 60-80 parts of volcanic rock, 6-9 parts of PA6 nylon powder, 3-4 parts of gelatin, 1-3 parts of ammonium bicarbonate, 5-8 parts of vermiculite powder, and deionized water. According to the invention, with the added vermiculite powder and iron tetroxide magnetic powder, volcanic rock absorbability, high-temperature resistance and fire resistance are enhanced; and an absorption range is expanded. The absorbent provided by the invention has good absorption characteristics in various fields and especially in the aspects of sewage treatment, oil pollution treatment and the like. The absorption efficiency is high, and the absorbent is easy to remove. The absorbent has a good reutilization effect, and has a good application prospect.

The invention discloses Fe3O4 ceramsite, a preparation method and applications thereof. The preparation method comprises: 1, weighing Fe3O4 powder and bentonite according to a mass ratio of (7-9):2, adding NaHCO3 accounting for 0.4-0.6% of the total mass of the Fe3O4 powder and the bentonite, completely mixing, adding water, and uniformly blending; 2, preparing a single pellet with a diameter of 5-10 mm from the mixture obtained in the step 1 by using a pelletizer; 3, drying the pellet prepared in the step 2 for 20-40 min at a temperature of 120-180 DEG C; and 4, sealing the dried pellet, roasting the pellets at 150-250 DEG C for 20-40 min, and naturally cooling to a room temperature of 20-30 DEG C to obtain the Fe3O4 ceramsite. According to the invention, the Fe3O4 ceramsite can be used as a wave-absorbing material so as to be used for microwave radiation inactivation of biological aerosols.

The invention provides a corrosion-resisting high-molecular material which is prepared from the components of, by weight: 50-80 parts of polyarylether ester, 10-20 parts of polybutylene, 5-20 of parts PET, 5-10 parts of triiron tetroxide, 1-5 parts of ferric oxide, 1-5 parts of copper oxide, and 1-5 parts of magnesium oxide. The specifications of the triiron tetroxide, ferric oxide, copper oxide, and magnesium oxide are 800-2000 meshes. The corrosion-resisting high-molecular material provided by the invention can resist corrosions of strong acids or strong oxidizing agents such as concentrated sulfuric acid, concentrated hydrochloric acid, chlorine-containing solvents, and the like. The application temperature of the material is higher than common high-molecular materials. Also, the cost of the material is lower than common high-molecular materials, and the production processes are existing processes, such that the material is suitable for industrialized productions.

The invention discloses a magnetic ZnO / Fe3O4 composite catalyst as well as a preparation method and application thereof. The preparation method of the composite catalyst comprises the following steps: under an inert atmosphere, dissolving iron oxide and zinc salt according to the ratio in a solvent, mixing an aqueous solution of sodium borohydride and carrying out reduction reaction and after the reaction is completed, drying the obtained precipitate to obtain the composite catalyst. The deficiencies of the prior art are overcome, the invention provides the magnetic ZnO / Fe3O4 catalyst which has the advantages of simple preparation, cheap raw materials and high catalytic activity and the preparation method thereof. By the catalyst, the removal rate of crystal violet in the Fenton reaction can be obviously increased.

The invention discloses a modified magnesite flue gas desulfurizing agent and a preparation method thereof. The modified magnesite flue gas desulfurizing agent is prepared from carboxymethyl chitosan,a macromolecular material, lauryl sodium sulfate, magnesite, tetraethoxysilane, ferroferric oxide powder and other raw materials. According to the modified magnesite flue gas desulfurizing agent disclosed by the invention, the modified magnesite is wrapped by two organic solutions, so that the surface tension of the desulfurizing agent can be reduced, the gas-liquid specific surface area is effectively enlarged, the mass transfer rate is increased, and the dispersivity of the desulfurizing agent is improved; the desulfurizing agent can be in more effective contact with sulfur dioxide, so thatthe adsorption intensity is enhanced, and the desulfurizing effect is increased; meanwhile, the modified magnesite flue gas desulfurizing agent is low in production cost, high in desulfurizing efficiency and high in system stability and can be widely used in the field of desulfurization.

The invention discloses a method for preparing triiron tetraoxide nanometer particles. A hyperbranched polymer is hydrophobically modified by fatty acyl chloride to prepare an amphiphilic hyperbranched polymer; and the highly dispersed triiron tetraoxide nanometer particles are prepared via a water / organic one-step solvothermal method by virtue of the micelle self-assembly effect of the amphiphilic hyperbranched polymer as a protective agent in a solution, the average particle size of the triiron tetraoxide nanometer particles is 8nm-35nm; the surfaces of the triiron tetraoxide nanometer particles are amphiphilically modified by virtue of encapsulation and dispersion effects of the amphiphilic hyperbranched polymer on the triiron tetraoxide nanometer particles, so that triiron tetraoxide nanometer particles are dispersed and stably exist in solvents with different degrees of polarity, at the same time, a plurality of active groups are given on the surface of the particles, the active groups provide possible sites for the secondary functionalization of particles and the application range of the triiron tetraoxide nanometer particles is extended.

The invention provides a method for detecting trivalent chromic ions by using gamma-polyglutamic acid stabilized triiron tetraoxide nano grains. The method comprises the following steps: adding a gamma-polyglutamic acid solution into an iron trichloride solution; stirring and adding a sodium sulfite solution; stirring and reacting; adding ammonia water under a water bath condition; reacting, centrifuging and dialyzing to obtain a gamma-polyglutamic acid stabilized triiron tetraoxide nano grain solution; adding a Cr<3+> solution into the gamma-polyglutamic acid stabilized triiron tetraoxide nano grain solution; mixing and then diluting; standing; and testing the change of relaxation time T2 of the triiron tetraoxide nano grains to obtain a quantitative relation between the concentration of Cr<3+> and the relaxation time T2. According to the method provided by the invention, the triiron tetraoxide nano grains are prepared by adopting the macromolecular structure property of gamma-polyglutamic acid; the preparation method is simple, the reaction conditions are moderate and the operation is easy; and the gamma-polyglutamic acid stabilized triiron tetraoxide nano grains prepared by the invention have good selectivity and extremely-high sensitivity on the detection of the trivalent chromic ions.