227 results about "Dimethyl formamide" patented technology

The invention belongs to the technical field of thermal management materials, and provides aerogel fibers of a three-dimensional porous structure and a preparation method and application of the aerogel fibers. The preparation method comprises the following steps: preparing a polyurethane spinning solution by taking N, N-dimethylformamide as a solvent; then carrying out wet spinning on the polyurethane spinning solution to obtain wet gel state fibers; and immersing the wet gel-state fiber into an organic solvent for solvent exchange, and drying after the solvent exchange is completed to obtain the aerogel fiber. The method is simple, low in cost and low in equipment requirement, efficient and continuous production of the aerogel fibers can be achieved, different spinning solutions can be adopted for preparing the aerogel fibers of different pore structures, meanwhile, the problem that the porous structures of the aerogel fibers are prone to collapsing when the aerogel fibers are dried at normal pressure is solved, and the aerogel fibers are suitable for large-scale production. The aerogel fiber with the three-dimensional porous structure is stable in porous structure, not prone to collapse, excellent in mechanical property and excellent in heat preservation and heat insulation performance.

The invention relates to a platinum-zinc alloy supported nitrogen-doped porous multi-layer carbon material and preparation and application thereof, the carbon material takes a rod-like graded porous carbon nanomaterial as a carrier, and platinum-zinc alloy particles and zinc monatomic are jointly supported on the surface of the carrier; the preparation method comprises the following steps: S1, adding zinc acetate and hexadecyl trimethyl ammonium bromide into DMF (Dimethyl Formamide), carrying out ultrasonic treatment, adding into a polyacrylonitrile solution, and stirring; s2, performing electrostatic spinning on the obtained spinning precursor solution; s3, adding the obtained nanofiber into a zinc acetate dihydrate solution, then adding a dimethylimidazole solution, carrying out hydrothermal reaction, soaking the obtained product in a chloroplatinic acid methanol solution, and then carrying out freeze drying; and S4, heating carbonization is carried out under the protection of an inert atmosphere, then annealing and cooling are carried out, and the PtZn-Zn-N4-HPCNFs material is obtained. Compared with the prior art, the catalytic performance and the like in the reaction processes of oxygen reduction reaction (ORR), chlorine evolution reaction (CER) and the like can be effectively improved.

The invention belongs to the technical field of chemical synthesis, and particularly relates to a method for preparing 5-methylfurfural by using 2-methylfuran. The special solid acid catalyst is used for replacing traditional phosphorus oxychloride, hydrogen chloride and phosphorus-containing wastewater are eliminated from the source, and the sulfolane is used for replacing DMF (Dimethyl Formamide), so that solvent residues in the product are reduced. The solid catalyst SO4 < 2-> is modified to form a strong Bronsted acid site (-SO3H) which cooperates with Ce < 3 + > / Ce < 4 + > redox to inhibit carbon deposition, selectively activate 2-methylfuran alpha-C and inhibit side reactions, so that the selectivity and yield of a target product are improved. Na2CO3 neutralization is replaced by electrochemical neutralization, salt slag solid waste is eliminated, and environmental pollution is reduced. After the organic phase is dried and dewatered through a molecular sieve, most of the solvent is removed through rotary evaporation, and the residual crude product is subjected to centrifugal molecular distillation, so that unreacted raw materials and trace impurities are effectively removed, and the product purity is remarkably improved.

The invention relates to a phase change energy storage fiber with ultraviolet shielding and heat regulation and control functions and a preparation method of the phase change energy storage fiber. The preparation method comprises the following steps: dissolving thermoplastic polyurethane in N, N-dimethylformamide to form a spinning mother solution; the preparation method comprises the following steps: firstly, adding nano titanium dioxide and uniformly dispersing, then adding a silicon dioxide shell layer-octadecane core layer phase change microcapsule, and stirring and ultrasonically defoaming to obtain a uniform composite spinning solution; extruding the spinning solution into a coagulating bath consisting of isopropanol and deionized water through an injection pump, and coagulating and forming to obtain nascent fibers; finally, washing, solvent replacement, tension setting and drying treatment are conducted, and compared with the prior art, the obtained fiber has efficient ultraviolet shielding performance and remarkable phase change energy storage capacity and has wide application prospects in the fields of intelligent temperature adjusting textiles, outdoor protective garments, building heat management and the like.

The invention discloses a degradable nanocellulose sustained-release drug-loaded film and a preparation method thereof, and belongs to the technical field of drug functional materials. The preparation method comprises the following steps: mixing and stirring microcrystalline cellulose and 64wt% sulfuric acid solution, centrifuging, dialyzing to be neutral, and freeze-drying to obtain CNCs; cNCs, NaIO4 and water are mixed and then subjected to a light-shielding reaction, ethanol precipitation is added, dialysis purification is conducted, freeze drying is conducted, and formylation modified CNCs are obtained; mixing and stirring the aldehyde modified CNCs, sericin, polyvinyl alcohol, water and a target drug to obtain a core layer solution; dissolving a polylactic acid-glycolic acid copolymer into a mixed solution of chloroform and DMF (Dimethyl Formamide) to obtain a shell solution; the core layer solution and the shell layer solution are subjected to coaxial electrostatic spinning forming to obtain the drug-loaded fiber, then the drug-loaded fiber is subjected to biomimetic mineralization surface modification to obtain the degradable nanocellulose sustained-release drug-loaded film, the drug loading rate is increased, the mechanical property of the drug-loaded film is improved, and the sustained-release and release-controllable effects are achieved.

The preparation method comprises the following steps: mixing cobalt acetate, a modified ligand, a modified additive and DMF (Dimethyl Formamide), carrying out ultrasonic treatment, adding deionized water and a modified filler, carrying out ultrasonic treatment, carrying out heating reaction, carrying out centrifugation to remove a supernatant, and carrying out drying treatment to prepare the rapid-charge high-capacity artificial graphite negative electrode material, when the cobalt acetate, the modified ligand, the modified additive and the modified filler are subjected to blending reaction, carboxyl on the modified ligand and carboxyl on the modified additive can form coordinate bonds with cobalt ions of the cobalt acetate, then a cobalt metal organic framework is formed on the surface of the modified filler, and a fluorine element in the modified ligand can react with lithium to form lithium fluoride; electron penetration is effectively blocked, and side reactions are reduced; the lithium ion diffusion energy barrier is reduced, rapid charging and discharging are achieved, pyridine groups on the surface of the modified filler can provide lone pair electrons and serve as binding sites of lithium ions, pseudocapacitance is formed, and then the capacity is increased.

The invention relates to the technical field of lithium-ion solid-state batteries, in particular to a three-dimensional polymer modified intermediate layer for a lithium-ion solid-state battery and a preparation method of the three-dimensional polymer modified intermediate layer, and the preparation method comprises the following steps: adding polyacrylonitrile into N, N-dimethylformamide, and stirring until the polyacrylonitrile is completely dissolved; and then adding the modified polyamide acid-phosphonate copolymer, continuously stirring to obtain an electrostatic spinning precursor solution, and carrying out electrostatic spinning on the electrostatic spinning precursor solution to obtain the composite nanofiber membrane. According to the invention, the indium-containing heterocyclic modified diamine is used as a core monomer of the polyamide acid-phosphonate copolymer, the lithium deposition nucleation overpotential can be reduced by the excellent lithium-loving activity of the indium-containing heterocyclic modified diamine, the lithium is enabled to be compact and free of dendritic crystal deposition, and the indium-containing heterocyclic group is uniformly dispersed in a three-dimensional framework through a cross-linked network of the modified polyamide acid-phosphonate copolymer, so that the performance of the polymer is improved. The contact interface of the intermediate layer and the lithium metal forms a global uniform lithium-loving site, and concentrated deposition of lithium atoms caused by local lithium-loving activity difference is avoided.

The invention belongs to the technical field of nano materials and environment-friendly functional coatings, and discloses a preparation method and application of a lignin-based super-hydrophobic coating. The method comprises the steps that lignin is pretreated with ethylene carbonate to break steric hindrance and improve the grafting rate, then hexadecyl trimethoxy silane is added for grafting to form a hydrophobic chain, and surface energy is reduced; then adding silicon dioxide and N, N-dimethylformamide, carrying out ultrasonic dispersion to synergistically construct a micro-nano coarse structure, spraying the micro-nano coarse structure on a base material by using a spraying method, and putting the base material into a drying oven for curing, so as to obtain the lignin-based super-hydrophobic coating material. According to the method disclosed by the invention, a high-activity epoxy group is grafted on a lignin skeleton through ethylene carbonate pretreatment, so that steric hindrance in a three-dimensional space is broken, and dense anchor points are provided for a subsequent hydrophobic chain; then cocondensing with hexadecyl trimethoxy silane to form an alkyl-siloxane double network, and cooperating with nano silicon dioxide to construct micro-nano double roughness, so that a stable super-hydrophobic core under a fluorine-free condition is realized, and the technical route is simple and efficient.

The invention provides halogen-free flame-retardant liquid epoxy resin, solid epoxy resin for powder coating and a preparation method of the solid epoxy resin, and belongs to the technical field of powder coating. The liquid epoxy resin disclosed by the invention is prepared by polymerizing 2, 4-diamino-6-phenyl-1, 3, 5-triazine, formaldehyde, triethyl phosphite, epoxy chloropropane, sodium hydroxide, DMF (Dimethyl Formamide) and the like. The contents of halogen-free flame-retardant elements nitrogen and phosphorus in the product are high, a solid epoxy resin product obtained by carrying out chain extension on liquid epoxy resin serving as a synthetic monomer of solid epoxy resin of the powder coating and bisphenol F is good in flame retardance, the oxygen index reaches 37% or above, and the flame retardance is high. A coating film obtained after the powder coating and an accelerated dicyandiamide curing agent are subjected to low-temperature rapid curing (150 DEG C / 10 min) is high in gloss and leveling grade and good in impact resistance, hardness and the like, and the application requirements of the powder coating are met.

The invention discloses a method for synthesizing N, N-dimethylformamide through electrochemical catalytic conversion of dimethylamine. The synthesis method provided by the invention comprises the following steps: by taking dimethylamine as a single substrate, carrying out in-situ electrochemical oxidation reaction to obtain N, N-dimethylformamide; a working electrode used in the in-situ electrochemical oxidation reaction is a composite electrode loaded with a co-oxide Cr2WO6 crystal. According to the synthesis method provided by the invention, only dimethylamine is used as a substrate, and the substrate is few in variety and low in concentration, so that the raw material cost is greatly reduced, and the damage of the high-concentration substrate to a catalyst and reaction equipment is reduced; in addition, the method is high in Faraday efficiency, has important practical application value for efficient resource utilization of dimethylamine, and has far-reaching significance in the aspect of carbon neutralization at present.

The application discloses a police clothing fabric convenient for heat dissipation and a processing technology, and the processing technology comprises the following steps: after carbon fibers are pretreated by a potassium permanganate solution and a KH550 aqueous solution, the carbon fibers are added into N,N-dimethylformamide, then ethylenediaminetetraacetic dianhydride is added into the mixture under stirring, and stirring reaction is carried out; the product is extracted, washed and dried to obtain ethylenediaminetetraacetic dianhydride modified carbon fibers; the modified carbon fibers are added into deionized water, then mannitol is added, concentrated sulfuric acid is used as a catalyst, and stirring reaction is carried out; the product is centrifuged, washed and dried to obtain modified carbon fibers; the modified carbon fibers and PET chips are mixed, then melt spinning is carried out, and the police clothing fabric convenient for heat dissipation is obtained through weaving; the fabric greatly improves the moisture absorption, sweat releasing, air permeability and heat dissipation performance of the fabric, improves the breaking strength of the fabric, and is suitable for being used as a police fabric.

The application relates to a super-hydrophobic cotton fabric and a preparation method thereof. The fabric can be prepared by the following method: firstly, a pore-forming agent and polystyrene are dissolved in dimethylformamide to prepare a spinning solution; secondly, the cotton fabric is pretreated; thirdly, the spinning is performed by using an electrostatic spinning technology; and finally, the super-hydrophobic cotton fabric is prepared by washing under the assistance of ultrasonic waves. The super-hydrophobic cotton fabric prepared by the application contains the hydrophobic material polystyrene on the surface, the apparent contact angle of water drops on the surface of the cotton fabric ranges between 151 DEG and 154 DEG, the super-hydrophobic property is very good, the hydrophobic property of the cotton fabric is not obviously weakened after 10 times of washing, and this indicates that the hydrophobic material polystyrene can be firmly attached to the surface of the cotton fabric.

The invention provides a preparation method of clindamycin hydrochloride alcoholate. The preparation method comprises the following steps: firstly, preparing a chlorination reagent from an oily solvent, DMF (Dimethyl Formamide), a chlorination solvent and an antioxidant; carrying out temperature-controlled chlorination reaction with lincomycin hydrochloride to obtain a chlorination reaction solution; adjusting the pH value of the reaction solution to 10-11, controlling the temperature to react, taking an oil phase after the reaction is finished, concentrating under reduced pressure, diluting with water, and adjusting the pH value to 3-5 to obtain a column loading solution; the preparation method comprises the following steps: dissolving clindamycin hydrochloride in water, adsorbing by using resin, eluting impurities by using dilute alkaline water, analyzing by using ethanol and deionized water in sequence, collecting an analysis solution, concentrating under reduced pressure, adding ethanol, heating for dissolving, adjusting the pH value to 1-1.5, cooling for crystallizing, and drying to obtain the clindamycin hydrochloride alcoholate. According to the preparation method disclosed by the invention, the clindamycin alcoholate with high yield and high purity is prepared by pertinently designing processes such as reaction conditions, a specific oily reagent, temperature control conditions, column adsorption, dilute alkaline water impurity elution, ethanol desorption and the like, only one-time crystallization is needed, repeated refining is not needed, the HPLC (High Performance Liquid Chromatography) purity is up to 99.5% or above, and the clindamycin alcoholate is suitable for industrial production. And 0.14% or less of 2, 7-epiclindamycin.

The invention provides SMMS non-woven fabric and a preparation method thereof, and belongs to the technical field of non-woven fabric. The preparation method comprises the steps of preparing the spunbond layer, preparing the melt-blown layer and compounding. The step of preparing the spunbond layer comprises the steps of preparing reinforced filler and mixing and forming; the preparation of the reinforced filler comprises the following steps: adding maleic anhydride grafted polypropylene into N, N-dimethylformamide, uniformly stirring, adding polypropylene oxide glycol and p-toluenesulfonic acid at 62-66 DEG C, heating to 120-130 DEG C, and refluxing for 3.5-4.0 hours in a nitrogen atmosphere to obtain a modified liquid; adding nano calcium carbonate into the modified liquid, controlling the temperature to be 78-83 DEG C, and adding polyglycerol fatty acid ester to obtain enhanced filler; according to the prepared SMMS non-woven fabric, the strength of the non-woven fabric is improved, meanwhile, the air permeability is guaranteed, and the SMMS non-woven fabric is good in production stability, good in softness, good in light aging resistance and excellent in overall stability.

The invention discloses a preparation method of a high-quality perovskite thick film for an X-ray detector, and relates to the technical field of radiation detection materials and devices. The preparation method of the thick film comprises the following steps: preparing a precursor solution from lead iodide, cesium iodide, formamidine iodide, methylamine iodide, 4-guanidinobenzoic acid hydrochloride, N, N-dimethylformamide and acetonitrile; a bulk phase functional additive is introduced to optimize a large number of Schottky defects at the grain boundary of the perovskite thick film; depositing onto a heated conductive glass substrate using a spray coating technique; and in combination with a low-temperature solvent atmosphere annealing process, secondary growth of crystal grains and grain boundary healing are promoted, and a large-area polycrystalline thick film can be obtained.

The invention discloses a warp-wise elastic tatting antibacterial fabric and a preparation method thereof, and belongs to the technical field of antibacterial fabric preparation. The preparation method of the warp-wise elastic tatting antibacterial fabric comprises the following steps: step 1, adding composite polyester particles into a mixed solution of N, N-dimethylformamide and acetone, heating and stirring, adding a modified antibacterial agent, and carrying out electrostatic spinning treatment, drying, hot pressing and cutting to obtain composite polyester staple fibers; 2, wool is treated to obtain pretreated wool, the pretreated wool is mixed with composite polyester staple fibers, an antistatic agent and emulsified oil are added, opening mixing, carding, drawing and roving processing are carried out, and mixed roving yarn is obtained; 3, spandex yarn serves as core yarn, the core yarn is wrapped with the pretreated wool, elastic wrap yarn is formed, the elastic wrap yarn and the mixed coarse yarn are mixed, spinning, weaving and heat setting are conducted, and the warp-wise elastic tatting antibacterial fabric is obtained. The fabric prepared by the method has excellent antibacterial property and mechanical property.

The invention belongs to the technical field of oil exploitation, and particularly relates to a clay stabilizer for an oil field as well as a preparation method and application thereof. The preparation method comprises the following steps: adding 1, 1 '-bis (4-aminophenyl)-[4, 4'-dipyridyl]-1, 1 '-ammonium dichloride, DMF (Dimethyl Formamide), triethylamine and (3-chloropropyl)-trimethyl ammonium chloride into a reactor, and carrying out a first heat preservation reaction; adding chloroalkane into the reactor, and carrying out a second heat preservation reaction; adding diacyl chloride into the reactor, and carrying out a third heat preservation reaction; and carrying out reduced pressure distillation to remove DMF to obtain a clay stabilizer crude product, adding water and ethyl acetate, fully mixing, separating out ethyl acetate, and carrying out reduced pressure distillation to obtain the clay stabilizer. The clay stabilizer has the advantages of high anti-swelling rate and washing resistance, the anti-swelling rate reaches 97% or above, and the washing anti-swelling rate reaches 93.5% or above.

The invention discloses a flexible glass cutting fluid and a preparation method thereof, and the preparation method comprises the following steps: S1, adding cellobiose into DMF, then adding chloroacetic anhydride and pyridine, and carrying out a stirring reaction to obtain an intermediate; s2, adding the intermediate into DMF (Dimethyl Formamide), and then carrying out constant-temperature reaction on glycerol monocaprylate, 2-(2-hydroxyphenyl) benzothiazole and triethylamine to obtain a modifier; s3, uniformly mixing a modifier, sodium dioctyl sulfosuccinate and a polyoxyethylene polyoxypropylene block copolymer, so as to obtain a composite surfactant; s4, adding the composite surfactant, the propylene glycol, the defoaming agent, the sterilizing agent and the triethanolamine into the water, and uniformly stirring to obtain the cleaning agent. According to the prepared cutting fluid, the protection effect on a flexible glass base material and a surface functional layer of the flexible glass base material is remarkably improved while the excellent wettability is kept, microcrack generation and surface damage in the cutting process are reduced, and the cutting fluid is particularly suitable for precise glass processing of flexible display devices.

The invention relates to the technical field of batteries, and discloses an electrolyte and application thereof, and a lithium carbon fluoride battery. The electrolyte comprises a lithium salt and an organic solvent; wherein the lithium salt is lithium bis (fluorosulfonyl) imide; the organic solvent is selected from one of ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene carbonate, propylene carbonate, dimethyl carbonate, ethyl methyl carbonate, dimethylformamide, dimethylacetamide and dimethyl sulfoxide. The electrolyte can be applied to preparation of a lithium primary battery. The invention also relates to a lithium carbon fluoride battery comprising the electrolyte. The electrolyte system provides an optimized solution for the preparation of the high-energy-density lithium carbon fluoride battery, has a wide application prospect, can remarkably improve the performance of the battery, reduces the production cost, and promotes the further development of the lithium carbon fluoride battery technology.

The invention belongs to the technical field of pharmaceutical analysis, and particularly relates to a method for determining a residual solvent in LXH-1211 by adopting headspace gas chromatography. Preparing a reference solution and a test solution of the LXH-1211, respectively carrying out headspace equilibrium on the blank solution, the reference solution and the test solution, injecting the solutions into a gas chromatograph in a headspace sample injection manner, recording a chromatogram, and calculating the content of the residual solvent in the test solution by peak area according to an external standard method; wherein the residual solvent is one or more of methanol, ethanol, dichloromethane, dioxane, N, N-diisopropylethylamine or N, N-dimethylformamide. The method is high in sensitivity, good in repeatability and high in accuracy, and can be used for simultaneously detecting the contents of various residual solvents in the LXH-1211, so that the quality of the LXH-1211 is ensured, and the safety of clinical medication is improved.

The invention discloses a high-flux interface modification method of an oxide-based all-solid-state battery and a lithium ion battery, and belongs to the technical field of solid-state lithium ion batteries. The method comprises the following steps: mixing LTFSI, PVDF-HFP, m-fluorobenzamide and LLZO powder, and adding dimethylformamide to obtain a mixed raw material; adding an organic wet grinding solvent into the mixed raw material, and carrying out ball milling to obtain interface modification slurry; and coating one side of an LLZO electrolyte sheet with the interface modification slurry, and drying to complete interface modification. According to the interface modification method disclosed by the invention, the solid electrolyte has a lithium-loving property, can be in good contact with a metal lithium negative electrode, and can generate LiFamp through an in-situ reaction; and Li3N fills up interface defects and pores, and meanwhile, lithium dendrite growth and electron permeation can be inhibited, so that the interface structure of the obtained modified layer is stable. In addition, the lithium ion conductivity at the interface is further improved, the lithium ion flux at the interface is enhanced, the cycle life of the lithium battery is prolonged, and the preparation method is simple and suitable for industrial large-scale production.

The invention discloses octavinyl polyhedral oligomeric silsesquioxane coupled brominated tetraphenylethylene as well as a preparation method and application thereof, and belongs to the field of fluorescent probes. Firstly, the rigid cage-shaped structure of POSS obviously enhances the aggregation-induced emission effect of TPE, so that the probe shows strong fluorescence emission in organic solvents such as DMF (Dimethyl Formamide) and the like; secondly, the probe shows an obvious solvent discoloration characteristic and shows adjustable optical response in different solvents, and meanwhile, the probe is endowed with excellent chemical stability by a POSS (Polyhedral Oligomeric Silsesquioxane) skeleton; thirdly, the probe has high selectivity and sensitivity recognition capability on heavy metal ions such as Fe < 2 + > and anions such as CN <->, the detection limit can reach 10 <-3 > mol / L, and visual detection can be realized through fluorescence change; in addition, a simple and convenient Heck coupling method is adopted for synthesis, the reaction condition is mild, the yield is up to 85%, and purification and large-scale production are easy.

The invention discloses a nitrogen-doped graphene composite material and a preparation method thereof, and belongs to the technical field of composite materials. The preparation method comprises the following steps: S1, preparing a nitrogen-doped graphene material; s2, dissolving indium nitrate, 2-amino-benzothiazole and the nitrogen-doped graphene material in a DMF (Dimethyl Formamide) aqueous solution, carrying out hydrothermal reaction, cooling to room temperature, washing and freeze-drying to obtain a nitrogen-doped graphene / indium-based MOF (Metal Organic Framework) material; and S3, adding the nitrogen-doped graphene / indium-based MOF material into the lead acetate dispersion liquid, carrying out ultrasonic treatment, stirring and uniformly mixing, dropwise adding a 2g / L sodium hydroxide solution into the mixed liquid in a stirring state until the solution Ph is 8, then carrying out freeze drying, putting a dried sample into a tubular furnace, and calcining in an inert atmosphere to obtain the nitrogen-doped graphene composite material. When the prepared composite material is applied to the negative electrode of the lead-acid battery, the hydrogen evolution side reaction in the charging process of the negative electrode plate can be remarkably reduced, and the electrochemical performance of the battery is improved.

The invention belongs to the technical field of organic synthesis, and particularly relates to a 3-fluoroisoquinoline-4-alcohol compound and a preparation method and application thereof.The preparation method comprises the steps that substituted 2-azido-2-fluoro-2, 3-dihydro-1H-indene-1-ketone reacts with a solvent; adding an extracting agent for extraction, taking an organic phase, drying, filtering and concentrating to obtain a crude product; and purifying to obtain the 3-fluoroisoquinoline-4-alcohol compound. The solvent is prepared from dimethyl sulfoxide, N, N-dimethyl formamide, acetonitrile, isopropanol, tetrahydrofuran, 1, 4-dioxane, dichloromethane and chloroform. Compared with the prior art, the invention solves the problems that the synthesis of isoquinoline compounds in the prior art needs multi-step reaction, the reaction conditions are harsh, and the tolerance of functional groups is poor. According to the scheme, the 3-fluoroisoquinoline-4-alcohol compound is obtained through one-step chemical reaction, and the method has the advantages that raw materials are simple and easy to obtain, the substrate range is wide, the reaction is mild, the yield is high and the like.

The invention provides an application of dimethylformamide in preparation of a product for preventing or treating androgenetic alopecia. When DHT (dihydrotestosterone) is used for constructing an androgenetic alopecia mouse model, it is found that after 30 mg / kg / d of dimethylformamide is given, the growth period of hair follicles is obviously accelerated, the hair density of a model mouse is effectively increased, and the hair recovery time is shortened. Organ-like experiments find that after the dimethylformamide treatment, the aggregation and fusion of the organ-like are obviously increased, and the NRF2 expression is also obviously enhanced. Therefore, the dimethylformamide has an effect of promoting the recovery of androgenetic alopecia and has the potential of being developed into corresponding medicines or cosmetics.

This invention provides a modified organic polymer, its preparation method, and its applications, relating to the field of environmental functional materials technology. The preparation method of the modified organic polymer includes the following steps: dissolving a metal compound in N,N-dimethylformamide solvent; adding an organic compound containing -COOH sites, ultrasonically dissolving, adding formic acid or acetic acid, mixing thoroughly, and carrying out a hydrothermal reaction at 160°C to 200°C for 20 to 28 hours; centrifuging to collect the precipitate, vacuum drying to obtain an organic polymer precursor; and alkalizing the organic polymer precursor in NaOH solution for at least 30 minutes to obtain the modified organic polymer product. By utilizing the empty electron orbitals surrounding the metal clusters to coordinate with the -COOH sites in the organic compound to form covalent bonds, the constructed modified organic polymer exhibits improved hydrophilicity, an increased number of active sites, and an optimized pore structure.

The invention discloses a preparation method of a wave-absorbing and heat-dissipating carbon fiber film and the wave-absorbing and heat-dissipating carbon fiber film. Cobalt salt and nickel salt are added into a first solvent, and a first mixed solution is obtained; adding a 1, 2-methylimidazole solution into the first mixed solution, standing, centrifuging to obtain a first precipitate, and drying the precipitate to obtain first powder; polyacrylonitrile fibers are dissolved in dimethylformamide, and a spinning solution is obtained; dispersing the first powder in dimethylformamide, adding a spinning solution, stirring to obtain a first emulsion, and performing electrostatic spinning on the first emulsion to obtain a carbon fiber membrane precursor; and performing high-temperature carbonization treatment on the carbon fiber film precursor to obtain the Co / Ni carbon fiber film. A reduced graphene oxide dispersion liquid and a Co / Ni carbon fiber membrane are provided as filtering media, the reduced graphene oxide dispersion liquid is subjected to suction filtration through a vacuum suction filtration method, a Co / Ni / rGO carbon fiber membrane is obtained, the Co / Ni / rGO carbon fiber membrane is dried, and the wave-absorbing and heat-dissipating carbon fiber membrane is obtained. The wave-absorbing and heat-dissipating carbon fiber film has good wave-absorbing performance and heat-dissipating performance.

The invention belongs to the field of preparation of lithium ion battery negative electrode materials, and particularly relates to a multi-stage silicon-carbon composite material for a battery negative electrode and a preparation method of the multi-stage silicon-carbon composite material. The method comprises the following steps: firstly, weighing DMF, Si NPs and PAN, carrying out ball milling, and then carbonizing in an N2 atmosphere to obtain a Si-C primary structure of a target sample; then uniformly dispersing Si-coated C and PAN in a DMF (Dimethyl Formamide) solution to obtain an electrostatic spinning working solution, and then preparing a Si-coated C composite PAN nanofiber membrane Si-coated C / PAN under an optimal electrostatic spinning working condition; and finally, stabilizing the fiber structure of the Si-coated C / PAN in the air, and carbonizing in the N2 atmosphere to obtain the multistage silicon-carbon composite material Si-coated C / CNFs for the battery negative electrode prepared by electrostatic spinning. According to the invention, an amorphous carbon layer is compounded on the surface of Si NPs by a ball milling method, and a carbon nanofiber network is built in combination with electrostatic spinning, so that the Si NPs are subjected to double constraints of amorphous carbon and carbon nanofibers. And the prepared silicon-carbon composite negative electrode material shows excellent cycling stability and rate capability.

The utility model provides a DMF (Dimethyl Formamide) tail gas recovery treatment device and belongs to the technical field of DMF tail gas treatment. Comprising a bottom plate, a supporting plate is installed at one end of the bottom plate and is in an L shape, a sliding groove is formed in the middle of the vertical end of the supporting plate, a lifting limiting assembly is installed in the supporting plate, a tank body is installed in the middle of the horizontal end of the supporting plate, the tank body is matched with a tank bottom plate, a vertical rod is installed in the middle of the upper portion of the tank bottom plate, and multiple sets of evenly-distributed containing frames are installed on the vertical rod. Through the arrangement of the lifting limiting assembly, the tank bottom plate, the vertical rods and the placing frames can be conveniently driven to integrally move up and down, the lifting plate is movably connected with the tank bottom plate, the tank bottom plate, the vertical rods and the placing frames can be conveniently taken out integrally, the replacement speed of activated carbon is high, the DMF tail gas absorption effect is guaranteed through the arrangement of the multiple sets of placing frames and iron gauze, and the service life of the DMF tail gas is prolonged. And the iron gauze does not hinder the movement of the DMF tail gas.

The present application relates to the technical field of organic synthesis, and particularly relates to a zinc-based fluorescent probe containing a pyridyl carboxylic acid type component, and a preparation method and application thereof. 22 H 14 N3O2)(CHO2)(H2O)·C3H7NO·3H2O; the zinc-based fluorescent probe containing the pyridyl carboxylic acid type component belongs to a monoclinic system, and a space group is P 2 1 / c ; cell parameters are a = 7.2925(2) Å, b = 26.6839(8) Å, c = 12.8618(4) Å, α = 90°, β = 105.5770(10)°, gamma = 90°. The zinc-based fluorescent probe has good thermal stability and large light emission intensity, the preparation method is simple, and the zinc-based fluorescent probe can be used as a fluorescent sensor to detect Fe 3+ and 2,4,6-trinitrophenol in a DMF solution with high sensitivity and high selectivity.