2281 results about "Dimethyl formamide" patented technology

The present invention relates to a high modulus macroscopic fiber comprising single-wall carbon nanotubes (SWNT) and an acrylonitrile-containing polymer. In one embodiment, the macroscopic fiber is a drawn fiber having a cross-sectional dimension of at least 1 micron. In another embodiment, the acrylonitrile polymer-SWNT composite fiber is made by dispersing SWNT in a solvent, such as dimethyl formamide or dimethyl acetamide, admixing an acrylonitrile-based polymer to form a generally optically homogeneous polyacrylonitrile polymer-SWNT dope, spinning the dope into a fiber, drawing and drying the fiber. Polyacrylonitrile/SWNT composite macroscopic fibers have substantially higher modulus and reduced shrinkage versus a polymer fiber without SWNT. A polyacrylonitrile/SWNT fiber containing 10 wt % SWNT showed over 100% increase in tensile modulus and significantly reduced thermal shrinkage compared to a control fiber without SWNT. With 10 wt % SWNT, the glass transition temperature of the polymer increased by more than 40° C.

An improved process for chlorination of sugars produces chlorodeoxy derivatives, in particular the chlorination of sucrose-6-esters to produce sucralose (4,1′,6′-trichloro-4,1′,6′-trideoxy galactosucrose), with thionyl chloride and N,N-dimethyl formamide (DMF) at the ration of about 1 molar equivalent of thionyl chloride for every molar equivalent of free hydroxyl group.

The invention discloses a high-yield preparing method for inorganic halogen perovskite fluorescent quantum dots at the room temperature. The fluorescent quantum dots are CsPbX3, wherein X is equal to AxB1-x and is larger than or equal to 0 and smaller than or equal to 1, and A and B are any one of Cl, Br and I. The method comprises the following steps that firstly, lead halide and cesium halide are dissolved into dimethyl formamide, surfactant oleylamine and oleic acid are added, the mixture is stirred until complete dissolution, and a precursor solution is obtained; secondly, the precursor solution is dripped into a poor solvent at the speed of 0.08-0.13 mL/s and stirred evenly at the uniform speed, and the inorganic halogen perovskite fluorescent quantum dots CsPbX3 are obtained. The preparing method is implemented at the room temperature, protection gas is not needed, equipment is simple, mass production can be achieved, and full visible light band shining can be achieved by selecting halogen and adjusting the proportion of halogen. The full width at half maximum of the inorganic halogen perovskite fluorescent quantum dots prepared through the preparing method ranges from 16 nm to 39 nm, the fluorescence quantum efficiency is close to 90%, and the inorganic halogen perovskite fluorescent quantum dots can be stably stored for more than three months, and can be used in the field of solar cells, lasers, light detectors, light-emitting diodes and the like.

The present invention discloses preparation and application of perovskite nanowires, a photoelectric detector and a solar cell. A preparation method of the perovskite nanowires comprises: (1) dissolving iodinated methylamine and haloid of lead in dimethyl formamide solution to prepare lead-halide perovskite precursor solution; (2) carrying out ultraviolet and ozone treatment on a substrate for at least 30 minutes to obtain the substrate with hydrophilcity; (3) roughening the edge of one end of the substrate and dispensing or spraying the lead-halide perovskite precursor solution on the substrate; and then jacking up the roughened edge end to enable an included angle to be formed between the substrate and the horizontal plane, carrying out standing and heating the substrate to obtain the lead-halide perovskite nanowires. According to the present invention, the lead-halide perovskite nanowires which are uniform in density and are ordered in direction can grow in a selective region of the substrate; and moreover, the grown lead-halide perovskite can be well combined with other parts or preparation methods of existing devices (for example, the lead-halide perovskite can be combined with other parts of the existing devices into the photoelectric detector, the solar cell and the like), so that performance of the devices are improved.

The invention discloses high-strength high-thermal-insulation silica aerogel and a preparation method thereof. The preparation method comprises the following steps: modifying halloysite with amino-terminated polysiloxane; adding ethyl orthosilicate, absolute ethyl alcohol, hydrochloric acid, dimethyl formamide and ammonium hydroxide to ensure a reaction and obtain gel; finally, carrying out carbon dioxide supercritical extraction to obtain the silica aerogel. As hollow natural clay fiber halloysite which is high in mechanical strength, low in thermal conductivity and high in thermal stability is taken as a reinforcing phase, the silica aerogel prepared according to the preparation method is relatively high in porosity, relatively low in density, excellent in mechanical property, favorable in heat-insulating property and relatively high in heat resistance.

The invention discloses a method for preparing a grapheme/silver nanoparticles composite material by using a liquid phase method. N and N-dimethyl formamide (DMF) serve as a reducing agent, grapheme powder with purity as high as 99% serves as a carrier, and silver forms a core and grows on a grapheme layer under a soft reaction condition to obtain the grapheme/silver nanoparticles composite material. The preparation method has the advantages of being simple, convenient, rapid and high-efficient in process, the grapheme/silver nanoparticles composite material prepared by using the method is high in purity and less in impurity content, and silver nanoparticles generated on the surface layer of the grapheme are small in particle size, uniform in distribution and high in bond strength with the grapheme. The silver nanoparticles are closely absorbed on the grapheme layer, aggregation of the grapheme is effectively avoided, and application of the grapheme/silver nanoparticles composite material in the fields of electron, catalysis, antibiosis and the like can be enlarged.

The invention relates to the technical field of nano materials and specifically relates to amino-modified silica with dual drug-loading effects. According to the technical scheme, firstly, mesoporous silica nanoparticles are prepared by a template method; secondly, surface amino modification is carried out onto the mesoporous silica nanoparticles by 3-aminopropyltriethoxy silane; thirdly, ursolic acid is chemically coupled to the spherical mesoporous silica nanoparticles by amido bonds; and fourthly, the coupled nanoparticles are dispersed in DMF (dimethyl formamide) solution; a proper amount of ursolic acid is added, mixed and stirred; and finally vacuum drying is carried out to obtain the amino-modified silica with dual drug-loading effects. The mesoporous nano material with dual drug-loading effects prepared by the mesoporous silica disclosed by the invention is high in loading rate, can achieve controlled release effect for the loading drug ursolic acid, so that drug effect lasts for a long period time, and therefore, bioavailability of the ursolic acid is greatly improved.

The invention relates to a polyurethane-polypeptide graft copolymer and a preparation method thereof. The graft copolymer is a comb-shaped polymer, wherein the molecular weight of polyurethane is 10,000 to 100,000; and the molecular weight of the polypeptide chain segment is 500 to 5,000. The preparation method comprises the following steps of: 1) synthesis of polyurethane provided with lateral carboxyl on the molecular chain: adding diisocyanate, polypropylene glycol, polyethylene glycol, dibutyltin dilaurate catalyst and dimethyl formamide solvent into a dry reaction bottle, performing stirring reaction under inert atmosphere, adding dimethylolpropionic acid dissolved in dimethyl formamide to react, adding butanediol to react, finally adding butanol to react, and obtaining a target product; and 2) synthesis of the polyurethane-polypeptide graft copolymer: putting the polyurethane provided with lateral carboxyl on the molecular chain, a solvent and a condensation agent into a dry reactor, adding polypeptide homopolymer into the reactor, and performing stirring reaction under the inert atmosphere to obtain a target product with pH response.

The invention discloses a method for producing real leather intimating polyurethane synthetic leather, which comprises the following steps: firstly, preparing a wet synthetic leather semi-finished product; secondly, coating a polyurethane finishing agent on the surface of the wet synthetic leather semi-finished product to perform printing surface treatment; thirdly, sticking a release paper pattern transferred polyurethane film to the surface of the printed wet synthetic leather semi-finished product, wherein raw materials in polyurethane slurry comprise polyester-polyether-polycarbon copolymerized polyurethane resin, cracking resin, dimethyl formamide, down powder, wet wax sensitive toner and solvent pigment; and finally, performing kneading treatment. The polyurethane synthetic leather has frosting effect on the surface, smooth handfeel, color change when pushing the surface by hand and strong third dimension of patterns, has good physical properties such as scratch resistance, cold resistance, hydrolysis resistance and the like, and can replace real leather in many aspects so as to reduce the requirement for furs, protect the nature and keep ecological balance.

A hydrophilic polyurethane dressing for wound is composed of the soft foam chips of hydrophilic polyurethane and the water-proof bacteria-isolating air and moisture permeable polyurethane film. Its preparing process includes such steps as mixing polygolyol, toluene diisocyanate (TDI-80) and propanetriol, stirring, reaction at 80-90 deg.C for 90-120 min to obtain prepolymer of polyurethane, mixingit with polyether, organotin catalyst, alamine catalyst pore-forming agent, stabilizer and water, foaming and ageing to obtain said soft foam chips, preparing the solution of said prepolymer in acetone and/or N,N-dimethyl formamide, adding water, filming, removing solvent, and solidifying reaction to obtain polyurethane film.

The invention discloses a metal/grapheme nanocomposite and a preparation method thereof. The method comprises a photo-reduction one-step method and a photocatalytic reduction one-step method. The photo-reduction one-step method comprises the steps as follows: a grapheme oxide and metal complex acid or inorganic salt and a photo-reduction agent are mixed at the room temperature or under the condition of an ice-water bath, and under the light condition, organic negative hydrogen donors reduce metal ions and the grapheme oxide, so that a product is obtained. One approach of the photocatalytic reduction one-step method comprises the steps as follows: the grapheme oxide and the metal complex acid or salt are mixed in a DMF (dimethyl formamide) water solution containing a reducing agent, a metal ligand and a photocatalyst or in a water solution, catalysis is performed through the catalyst under the light condition, and at the same time, the reducing agent reduces the metal ions and the grapheme oxide, so that a product is obtained; and the other approach of the photocatalytic reduction one-step method comprises the steps as follows: the grapheme oxide and a metal organic complex are mixed in a DMF water solution containing the reducing agent and the photocatalyst or in a water solution, then catalysis is performed through the catalyst under the light condition, and the reducing agent reduces the metal organic complex and the grapheme oxide, so that a product is obtained.

The invention discloses a method for preparing a G/Sn/PAN-base carbon nanometer fiber membrane. The method for preparing the G/Sn/PAN-base carbon nanometer fiber membrane includes: 1) preparing spinning solution, to be more specific, weighing polyacrylonitrile, nanometer tin powder and graphene nanometer film according to certain mass ratio, blending and dissolving in N-N dimethyl formamide, and stirring to obtain the uniformly dispersed electrostatic spinning solution; b) electrostatic spinning, to be more specific, carrying out electrostatic spinning on the electrostatic spinning solution of the step a) to obtain a graphene/tin/polyacrylonitrile nanometer fiber membrane; c) pre-oxidizing, to be more specific, pre-oxidizing the graphene/tin/polyacrylonitrile nanometer fiber membrane of the step b) in air atmosphere to obtain the pre-oxidized nanometer fiber membrane; d) carbonizing, to be more specific, carbonizing the pre-oxidized nanometer fiber membrane in argon atmosphere to obtain the G/Sn/PAN-base carbon nanometer fiber membrane. The method for preparing the G/Sn/PAN-base carbon nanometer fiber membrane is easy to operate, the graphene coats the nanometer fiber well; the G/Sn/PAN-base carbon nanometer fiber membrane has advantages of large specific surface area, high porosity, and high electrical conductivity and so on, and has broad expanding space.

A polyacrylnitrile-base carbon fibre spinning liquid is prepared from acrylnitrile, dimethyl formamide, distilled water, azodiisobutylnitrile and chain transfer agent through homopolymerization, introducing ammonia gas to stop reaction, and regulating pH value by ammonia gas. Its advantages are uniform distribution of function groups on macro-molecular chain, simple process and easy control.

Disclosed is a method for making pH sensitive PVDF hollow fiber intelligent film and products made thereby, wherein the making process comprises the steps of, (1) steeping the film in pure water for 24 hours, (2) preparing 10-20% alkali solution, and charging 3-4gl/L of tetrabutylammonium bromide, charging immersed film in alkali solution, heating by water bath, (3) preparing 1-2 mol/L of AAC solution, charging dimethyl formamide solution by 40-50ml/L, mixing uniformly, charging alkali-treated film in the mixed solution, steeping 10-20 minutes at room temperature, preparing solution of crosslinking agent 0.01-0.09mol/L and K2S2O3 0.1-0.3g, charging the readily made film into the solution, filling N2 and sealing, water-bathing, heating and washing with deionized water, the crosslinking agent is MBAA or diacrylic acid ethylene glycol ester.

The invention discloses a preparation method for a high-dielectricity polyvinylidene fluoride/poly-dopamine-coated graphene nanocomposite. The method comprises the following steps: graphene oxide is prepared through a Hummers oxidation method, dopamine is automatically polymerized under the alkaline condition to coat the surface of the graphene oxide, reduction is performed on the poly-dopamine graphene oxide through hydrazine hydrate, centrifugal washing is performed repeatedly for removing impurities, the obtained poly-dopamine-coated grapheme can disperse in N, N-dimethylformamide well after being subjected to ultrasonic treatment, the polyvinylidene difluoride and the poly-dopamine-coated graphene are mixed through a solution method, and hot press molding is performed on the mixture, so that the nanocomposite is obtained. The preparation process is simple and easy to operate, the repeatability is good, the composite is good in flexibility and machinability, and has high potential for being applied to dielectric materials of energy storage parts such as capacitors.

The invention relates to a preparation process of a metal-organic framework porous adsorption material for C4-C8 normal paraffin and isoparaffin adsorption separation. According to the preparation method of the synthesized metal-organic framework porous adsorption material, metal ion nitrate and an organic ligand are dissolved according to the mass ratio of 1:1-15 in a mixed solution of N,N-dimethylformamide and N,N-diethyl formamide; stirring is carried out for 0.5-12 h; reaction temperature is controlled to 80-250 DEG C, and reaction time is 12-120 h; and by a hydrothermal synthesis method, the metal-organic framework porous adsorption material is prepared. The material has characteristics as follows: specific surface area is large; pore structure height is ordered; pore size is controllable; surface potential energy is controllable; and adsorption capacity of normal paraffin is large. The material can selectively adsorb normal paraffin from mixed materials of normal paraffin and isoparaffin, has high selectivity and has a wide practical application prospect in normal paraffin and isoparaffin separation.

The invention relates to a blocking remover of a gas well shaft. The blocking remover comprises, by weight, 5-25% of an alcohol ether compound, 0.5-10% of a dispersant, 1-10% of a cleaning agent, and 0.5-5% of chelating agent, with the balance being a nitrogen-containing polar solvent, wherein the nitrogen-containing polar solvent is one selected from N,N dimethyl formamide, N,N dimethyl acetamide, and N-methyl pyrrolidone, the alcohol ether compound is one selected from glycol-ether, glycol-propyl ether, glycol-butyl ether, and diglycol-ether, the disperant whose micelle particle size is from 20nm to 100nm is a middle-phase microemulsion-type dispersant mixed by kerosene, water, a surfactant and a cosurfactant, the cleaning agent is one selected from allene diamine, acetonitrile and pentylamine, and the chelating agent is one selected from sodium citrate and EDTA. The blocking remover has the advantages that corrosivity is weak, that the speed of dissolving blockage is fast, that the product performance is stable in high temperatures, and that the blocking remover can reduce damages caused by water locking and fouling in areas close to gas wells, and can recover the permeability of storing layers.

The invention discloses a large-scale adsorbing material ZIF-8 synthesizing and forming methods, and belongs to the technical field of adsorbing materials. The method comprises the steps of: pouring 70-75ml of dimethyl formamide (DMF) into a polytetrafluoroethylene liner with the volume of 100ml, and adding Zn(NO3)2.6H2O and 2-methylimidazole according to a molar ratio of 1:(2-4) to be fully dissolved; crystallizing under self-generated pressure; heating from a room temperature to a preset crystallization temperature through programs, and then preserving a constant temperature for a plurality of hours; cooling, filtering in vacuum and washing; weighing and putting ZIF-8 powder into a mortar, and adding an adhesion agent to be completely ground together; then adding a peptizing agent, and completely grinding the peptizing agent in the mortar until wet fine powder is formed; and tabletting the obtained wet fine powder through a tabletting machine so as to obtain a platy ZIF-8 mateiral. The ZIF-8 synthesized by the method has high crystallinity and good adsorption property.

The invention belongs to the technical field of metal organic framework materials, and discloses a zinc and copper bi-metal organic framework material and a preparation method and application thereof. The preparation method comprises the steps that 1, soluble copper salt, soluble zinc salt and trimesic acid are added to mixed solvent of N,N'-dimethyl formamide, water and ethyl alcohol, even stirring and ultrasonic treatment are conducted, and reaction liquid is obtained; 2, the reaction liquid obtained in the first step is transferred into a polytef reaction kettle for a hydrothermal reaction, and a roughly prepared zinc and copper bi-metal organic framework material is obtained; 3, the material obtained in the second step is washed through the N,N'-dimethyl formamide firstly and then soaked through ethyl alcohol solvent, and the purified zinc and copper bi-metal organic framework material is obtained after activation is conducted. According to the zinc and copper bi-metal organic framework material, the framework structure of an original copper-based organic material is reserved; meanwhile, the prepared material is large in specific surface and developed in micro-pore structure and has higher adsorption capacity to low-concentration congo red dye molecules in water.

The invention relates to a method for preparing silicon dioxide-nanometer noble metal composite microspheres. The method comprises the following steps of: 1) preparing modified silicon dioxide colloid microspheres; 2) dispersing the modified silicon dioxide colloid microspheres in dimethyl formamide (DMF), adding an organic monomer and an initiator for reacting, performing centrifugal separation, washing, and drying to obtain silicon dioxide/polymer composite microspheres; and 3) dispersing the silicon dioxide/polymer composite microspheres in deionized water, dripping a AgNO3 solution, stirring, dripping a reducing agent dropwise, stirring, performing centrifugal separation, washing and drying to obtain the silicon dioxide-silver nanometer composite microspheres. The method has the advantages that the silicon dioxide metal composite material which is high in dispersion degree and firm in combination, and of which the metal ion diameter is small can be obtained under the mild reaction condition; and the specific surface areas of the noble-metal-loaded silicon dioxide composite particles have adjustability. The method can be used for preparing the silicon dioxide silver-loaded nanometer particles, and also can be used for loading other noble metal nanometer particles by silicon dioxide.

The invention provides a piece of novel sewing-free hot melt adhesive TPU-PU leather, and a preparation method thereof. The TPU-PU leather comprises release paper, a hot melt adhesive film, a TPU film and a dry-type PU film, wherein the release paper comprises a paper bottom layer, an adhesive layer, a plastic layer, a transition layer, and a release layer; a hot melt adhesive raw material is composed of polyester polyol, diisocyanate, polyether polyol, and a plurality of additives; a TPU raw material is composed of polymer polybasic alcohol, 1,4-cyclohexane-diisocyanate, a chain extender and a plurality of functional additives; a PU raw material is composed of polyester dibasic alcohol, straight chain diol, isocyanate, TDI trimer, dimethyl formamide, butanone, black sand, and a plurality of functional addictives. Through the adoption of the preparation method, innovations are conducted on the raw material components of the release paper, the hot melt adhesive, the TPU film and the PU film; the manufactured sewing-free TPU-PU leather has the technical advantages of firmness in adhesion, durability, environment-friendly materials, no invisible harm to a human body, and the like.

The invention relates to a method for manufacturing series silver nano-sheets in a batch. The method includes dividing polyhydric alcohol, dimethyl formamide, high-polymer surfactant, metal salt adjuvant containing halogen and metal silver salt into three batches to be treated by the aid of the metal salt adjuvant containing the halogen; then uniformly mixing the materials; and obtaining the series silver nano-sheets by means of heating reaction. The silver nano-sheets are uniform in shape, high in purity, fine in monodispersity and low in cost, a reaction device is simple, large-scale preparation of the silver nano-sheets can be realized, and the method has an industrial prospect.

A process for the preparation of a sulfonamide of formula (II), comprising reacting at elevated temperature an aniline of formula (I), with a sulfonating agent A of the formula R¹—SO₂-Z in the presence of a catalytic amount of either: (i) an amide B-1, other than N,N-dimethylformamide, or (ii) a high boiling tertiary amine B-2. Also provided in accordance with the present invention are processes for preparing sulfonamides of formula (II) by reacting an aniline of formula (I) with sulfanating agent A of the formula R¹—SO₂-Z in the presence of N,N-dimethylformamide, at a temperature in the range of about 120° C. to about 160° C. for about three to about seven hours. X, Y, Z, R and R¹ are defined herein

The invention relates to a method for manufacturing a CTI copper-clad laminate. The method is realized by the following steps: glue mixing, sizing, plate arrangement, hot-press molding, disassembly, processing and inspecting, wherein an adhesive system in the step of the 'glue mixing' is composed of the following materials in mass ratio (kg): 125 to 133 kg of low brominated epoxy resin, 2.60 to 3.40 kg of dicyandiamide, 30 to 36 kg of dimethyl formamide, 0.060 to 0.080 kg of dimethyl imidazole, and 10 to 40 kg of aluminum hydroxide, wherein the low brominated epoxy resin belongs to tetrabromobisphenol A type brominated epoxy resin, and the content of bromine accounts for 10 to 14 mass percent of the low brominated epoxy resin. The method has the advantage of improving the tracking voltageresistance of a PCB substrate.

The invention belongs to the field of environment pollution treatment, and more specifically relates to a preparation method and applications of a nanometer titanium dioxide @ Fe-based MOF visible light composite catalyst. The preparation method comprises following steps: a ferric iron salt, 2-amino terephthalic acid, and nanometer TiO2 are added into N, N-dimethyl formamide, ultrasonic uniform dispersion treatment is carried out so as to obtain a precursor solution; the precursor solution is subjected to hydro-thermal reaction so as to obtain the nanometer titanium dioxide @ Fe-based MOF visible light composite catalyst. Under sun light effect, the nanometer titanium dioxide @ Fe-based MOF visible light composite catalyst is capable of realizing high efficiency reduction of Cr(VI) under mild neutral conditions, efficiency is high, energy consumption is low, and the nanometer titanium dioxide @ Fe-based MOF visible light composite catalyst is widely suitable for processing of a plurality of chromium containing waste water.

The invention discloses an adsorption-photocatalysis composite material synthesized on basis of in-situ synchronous assembly of UIO-66-NH2 and graphene (GR). The composite material is prepared by following steps: (1), weighing a certain amount of GR, dissolving the same in N, N-dimethyl formamide prepared in advance, and performing ultrasonic treatment to enable GR to be dissolved in a solution to obtain a solution A; (2), weighing a certain amount of 2-amino-terephthalic acid, dissolving the same in the solution A, ultrasonically treating, and stirring to obtain a solution B; (3), weighing a certain amount of a precursor, zirconium tetrachloride used for synthesizing MOF, dissolving the precursor in the solution B, ultrasonically treating, and stirring to obtain a solution C; (4), putting the solution C in microwaves for reaction for a period of time to obtain a product; (5), centrifuging and washing the product to obtain the composite material of UIO-66-NH2 and GR.

The invention discloses a method for preparing an anti-polluting efficient oil-water separation ultra-filtration membrane, which comprises the following steps of: dissolving 16.0 mass percent of cellulose acetate into an N,N-dimethyl formamide solvent based on 100 percent of the mass of membrane casting solution, adding 15.0 to 30.0 mass percent of ethyl orthosilicate, and scraping a nascent state membrane with thickness of 240 microns on a glass plate; placing the nascent state membrane in the air for 10 to 30 seconds, and then soaking the nascent state membrane into gel baths of 25 DEG C, wherein the gel baths are aqueous solution of hydrochloric acid and aqueous solution of sodium hydroxide respectively; and taking out the membrane from the gel bath, placing the membrane into deionizedwater, and changing the water once every 5 hours to obtain the CA(TEOS)-HCl and CA(TEOS)-NaOH modified ultra-filtration membrane. The method is simple in process and mild in conditions; and the flux of the modified membrane is greatly improved, good anti-polluting performance is kept, and the modified membrane has high interception rate and can be used for treating oil-containing wastewater.

The invention discloses a graphene/Fe-MOFs composite material and a preparation method thereof. Adding oxidized graphene, FeCl3 and terephthalic acid into N, N-dimethyl formamide according to the corresponding ratio of 1-15 g : 100 g: 200 g : 150 ml, ultrasonically dissolving the mixture at a power of 600 W for 1 h, and then controlling the temperature to be at 150 degrees to conduct hydrothermal reduction reaction for 15 h; conducting suction filtration on the obtained reaction liquid, conducting repeated washing and suction filtration on the filter cake with N, N-dimethyl formamide till the filter does not contain incompletely reacted oxidized graphene, FeCl3 and terephthalic acid, controlling the temperature to be at 80 degrees to conduct drying, and then the graphene / Fe-MOFs composite material with good electro-chemical performance is obtained and can be used for super capacitor electrode materials. The graphene / Fe-MOFs composite material is simple and controllable in preparation technology, mild in conditions, low in production cost and suitable for industrial production.

The invention relates to a preparation method of a sodium alginate nanofiber, belonging to the field of natural biological polymer materials. The preparation method comprises the following steps: dispersing sodium alginate powder in an ethanol solution, and adding water to regulate the concentration to 4-6 wt%; dropwise adding a crosslinking agent while stirring, and then standing, wherein the content of the crosslinking agent is 1-3 wt% of the sodium alginate; after bubbles emerge, dropwise adding a N,N-dimethyl formamide water solution while stirring, and then standing, thereby obtaining a sodium alginate spinning solution the concentration of which is 0.5-2 wt% after the bubbles emerge; adding the spinning solution into an injector, regulating the voltage to 10-25kV, regulating the distance between a sprayer and a receiver to 5-25cm, and regulating the flow rate to 0.1-1 ml/h; and starting a spinning device. The invention aims at the complicated after-treatment processes of crosslinking, washing, drying and the like for obtaining a pure SA (sodium alginate) nanofiber at present. The method can be used for directly preparing a slightly-crosslinked SA nanofiber, and a solvent can sufficiently volatilize in the spinning process.

The invention discloses a simple green synthesis method of nitrogen-doped carbon quantum dots. Konjac flour, serving as a carbon source, is subjected to pyrolysis in air and solvent extraction to obtain the nitrogen-doped carbon quantum dots. The synthesized nitrogen-doped carbon quantum dots are easily dissolved in solvents such as ethanol, N,N-dimethyl formamide and dimethyl sulfoxide and can be ultrasonically dispersed in water, the particle size is 0.3-2.4 nm, the highest fluorescence quantum yield is 22%, and the yield is 3%-5%. The nitrogen-doped carbon quantum dots can emit blue light, green light and red light respectively under the excitation of ultraviolet light, blue light and green light, and the fluorescence property of the nitrogen-doped carbon quantum dots can be adjusted through the excitation light wavelength, concentration and pH value. The method is simple and easy to operate and can be applied to large-scale synthesis of carbon quantum dots while the cost is low. The synthesized nitrogen-doped carbon quantum dots can be applied to the development of living cells in vitro and the preparation of stimulus response materials, and have broad application prospects in multiple fields of biomarkers, biomedical imaging, bio-development, drug screening and detection, biochips, biosensing and the like.