226 results about "Acetic acid solution" patented technology

The invention discloses a graphene oxide-chitosan-carboxymethyl cellulose composite aerogel and an application of the graphene oxide-chitosan-carboxymethyl cellulose composite aerogel in adsorption of amaranth. The preparation method comprises the following steps: mixing a carboxymethyl cellulose aqueous solution with a chitosan acetic acid solution, adding gallic acid, stirring until the gallic acid is completely dissolved, adding the graphene oxide dispersion liquid, and stirring until a system forms uniform and stable gel; the gel is firstly subjected to ultralow-temperature freezing and then subjected to freeze drying, and finally the graphene oxide-chitosan-carboxymethyl cellulose composite aerogel is obtained. The aerogel prepared by the method is environment-friendly and stable in pore structure, and is a composite aerogel material with high adsorption capacity and good regeneration performance on anionic dyes. The adsorption capacity of the aerogel to amaranth can reach 125 mg / g, the adsorption rate is still kept at 77% after the aerogel is recycled for 3 times, and the aerogel is suitable for efficient treatment of dye wastewater.

The invention relates to a method for recovering lithium and fluorine from aluminum electrolysis hazardous waste, which comprises the following steps: firstly, mixing organic polyol and alkaline hydroxide according to a molar ratio of 1: (0.5-2) to obtain a eutectic solvent; heating the eutectic solvent to 80-150 DEG C, and adding a proper amount of raw material fine powder and calcium oxide for reaction leaching; carbonating and filtering the leachate to obtain lithium carbonate; washing the leaching residues with an acetic acid solution to obtain a calcium fluoride product; the concentration of fluorine ions in the leachate is smaller than or equal to 200 ppm, and the purity of calcium fluoride is larger than or equal to 90%; the leaching rate of lithium in the method is greater than 85%; the slag feeding rate of fluorine is greater than 95%; and no hydrogen fluoride gas is generated in the method. According to the method, a non-toxic and biodegradable eutectic solvent is adopted as a leaching agent, and efficient leaching of lithium and fluorine in the aluminum electrolysis dangerous waste materials is achieved; calcium oxide is used as a precipitating agent, free fluorine is promoted to be precipitated and recycled as calcium fluoride, the whole process meets the requirement of green metallurgy, and the win-win situation of resources and the environment is achieved.

The application discloses a kind of nano magnetic flocculants and its preparation method and application, belong to drinking water processing technical field, including the following steps: step S1, modified ferroferric oxide nanosphere is ultrasonically dispersed in ammonia alcohol solution, while stirring, slowly drop adding tetraethyl orthosilicate, continue stirring after drop, after centrifugal separation, wash, obtain silica coated ferroferric oxide nanoparticles;Step S2, phenylalanine modified chitosan is added into glacial acetic acid solution, after completely swelling and dissolving, add silica coated ferroferric oxide nanoparticles and ultrasonic treatment, under low pressure ultraviolet lamp, then with anhydrous ethanol wash purification, vacuum drying to constant weight, obtain nano magnetic flocculants;The method of the application is simple and easy to operate, the nano magnetic flocculants prepared can be quickly adsorbed to the surface of sulfonamide antibiotics, produce flocculation and can be magnetically separated, very suitable for trace sulfonamide antibiotics in drinking water source efficient removal.

The invention belongs to the technical field of high polymer chemistry and composite materials, and particularly relates to a composite proton exchange membrane and a preparation method thereof. The method comprises the following steps: adding an original multi-walled carbon nanotube into a mixed acid solution, and carrying out oxidation treatment to obtain an acidified carbon nanotube; carrying out condensation reaction on the acidified carbon nanotube, a condensing agent and sulfanilic acid in a solvent system to obtain a sulfonated carbon nanotube; dispersing the sulfonated carbon nanotubes in an acetic acid solution to form a dispersion liquid, dissolving chitosan in the acetic acid solution to form a chitosan solution, and mixing the dispersion liquid with the chitosan solution to prepare a membrane casting solution; forming a membrane from the membrane casting solution to obtain an initial composite proton exchange membrane; and placing the initial composite proton exchange membrane in a sulfuric acid solution for crosslinking treatment, washing and drying to obtain the target composite proton exchange membrane. Based on the method, the technical effect of preparing the proton exchange membrane with excellent comprehensive performance is achieved.

The invention belongs to the technical field of fine chemical synthesis, belongs to a nonionic short fluorine chain surfactant, and relates to a preparation method of a fluorinated polyether surfactant. The preparation method comprises the following steps: reacting trimethylolethane with a hydrogen bromide acetic acid solution to prepare an intermediate 1; reacting the intermediate 1 in an alkaline environment without an organic solvent to prepare an intermediate 2; reacting the intermediate 2 with pentafluoropropanol under the action of potassium hydroxide and a catalyst 1 to prepare a fluorinated monomer; finally, the fluorinated monomer is subjected to ring opening polymerization under the action of an initiator and a catalyst 2, and the fluorinated polyether type surfactant is prepared. The method has the advantages of easily available raw materials, mild reaction conditions, simple synthesis, low cost, high yield and short fluorine chain of the product, can replace a long-chain fluorine-containing surfactant which is difficult to degrade, and can be used as an additive in the fields of photoresists, coatings, adhesives and the like. The surface tension can be obviously reduced, the surface defects of a coating can be reduced, and the appearance can be improved by adding a very small amount of the surface tension reducing agent.

The application discloses a plant-based sewage filtering membrane and a preparation method thereof, and relates to the technical field of membrane materials. In the preparation of the plant-based sewage filtering membrane, tetraethyl orthosilicate, zinc acetate, an acetic acid solution and a polyvinyl alcohol solution are mixed, and then electrostatic spinning and calcination are performed to obtain a flexible base film. After the flexible base film is treated with trimethoxysilane, one side of the flexible base film is grafted with diethyl allyl malate, and the other side of the flexible base film is grafted with allyl trimethyl ammonium chloride. After treatment with hydrochloric acid, the plant-based sewage filtering membrane is obtained. The plant-based sewage filtering membrane prepared by the application has good flexibility, sewage filtering effect and antibacterial performance.

This invention discloses a bioactive glass and its preparation method, belonging to the field of bioactive glass technology. It aims to solve the problems of insufficient synergistic effect between antibacterial efficacy and bone-promoting activity in existing materials, as well as the inability to monitor in vivo degradation processes in real time. The bioactive glass comprises 44-48 parts silica; 22-27 parts calcium oxide; 22-27 parts sodium oxide; 5-7 parts phosphorus pentoxide; 2-4 parts europium zinc complex; 10-20 parts chitosan; 1-5 parts lidocaine; and 2-5 parts dilute acetic acid solution. The addition of the europium zinc complex promotes bone formation and enhances antibacterial activity, achieving a highly efficient synergy between anti-infection and tissue regeneration. Simultaneously, it provides optical tracking capabilities, allowing for non-destructive real-time monitoring of the material's degradation behavior and tissue integration in vivo via fluorescence imaging. This invention offers superior material performance and a simple preparation process, providing an innovative solution for the repair of infected bone defects.

The application discloses sewage treatment composite purifying agent and a preparation method and application thereof, and comprises the following steps: S1, nanometer aluminum powder is mixed with zeolite and is ball milled to obtain nanometer aluminum powder@zeolite inclusion compound; S2, chitosan is dissolved in acetic acid solution, and mercapto acetic acid is added to react to obtain mercapto chitosan; then the mercapto chitosan is dissolved in acetic acid solution, and a trivalent iron source solution is added dropwise to obtain mercapto chitosan-trivalent iron coordination gel; S3, tea saponin is mixed with beta-cyclodextrin to obtain tea saponin-beta-cyclodextrin inclusion compound; S4, porous ceramic granules, nanometer aluminum powder@zeolite inclusion compound, mercapto chitosan-trivalent iron coordination gel, microcrystalline cellulose and citric acid are uniformly mixed, water is added to granulate to obtain an inner core; S5, sulfur powder is melted, carbonate powder, maifanite powder and tea saponin-beta-cyclodextrin inclusion compound are added to obtain molten slurry, the inner core is added, and stirring is carried out to coat, so that the sewage treatment composite purifying agent is obtained; the sewage treatment composite purifying agent can stably remove various pollutants with high efficiency and can adapt to complex water bodies.

This invention provides a covalent organic framework hybrid matrix membrane, its in-situ growth method, and its application in ion separation. The method includes: dissolving cellulose derivatives, aldehyde monomers of covalent organic frameworks, and amine monomers of covalent organic frameworks in an organic solvent to obtain a first solution, a second solution, and a third solution; mixing acetic acid solution with the first, second, and third solutions to obtain a homogeneous casting solution; and drop-coating the homogeneous casting solution for in-situ growth. This invention constructs a CD@COF hybrid matrix membrane based on a cellulose derivative matrix and a low-loading covalent organic framework filler using an in-situ growth method. The prepared hybrid matrix membrane exhibits good interfacial compatibility between the matrix and the filler. The above-mentioned hybrid matrix membrane preparation process is simple, possesses good mechanical strength and high scalability, and demonstrates high ion flux and excellent ion selectivity for separating monovalent and divalent ions. It has broad application prospects in wastewater resource treatment, lithium extraction from salt lakes, and energy storage.

The invention discloses a poria cocos water-soluble polysaccharide preparation method based on enzyme-alkali synergy. The poria cocos water-soluble polysaccharide preparation method comprises the following steps: S1, crushing poria cocos to obtain poria cocos powder; mixing with ethanol, stirring and extracting; mixing with distilled water, stirring and extracting, and finally drying; s2, mixing the obtained system with a sodium hydroxide solution, stirring at room temperature, and centrifuging to obtain supernate; adjusting the pH value of the supernate by using an acetic acid solution, standing, repeatedly washing by using distilled water, and freeze-drying to obtain the alkali-soluble polysaccharide of the poria cocos; and S3, dissolving the obtained system in a sodium hydroxide solution, adding a compound enzyme, carrying out an enzymatic hydrolysis reaction, and carrying out enzyme deactivation, centrifugation, tetraploid volume ethanol precipitation, dialysis and freeze-drying on an enzymatic hydrolysate to obtain the poria cocos water-soluble polysaccharide. The invention provides a poria cocos water-soluble polysaccharide preparation method based on enzyme-alkali synergy, poria cocos alkali-soluble polysaccharide is used as a substrate, the poria cocos water-soluble polysaccharide is prepared by complex enzyme, and the extraction rate and activity of the poria cocos water-soluble polysaccharide are improved. The invention further discloses application of the poria cocos water-soluble polysaccharide.

The present invention relates to the technical field of biodegradable materials. Disclosed is a preparation method for a bioactive glass fiber reinforced polylactic acid composite material. The preparation method comprises the following steps: (1) subjecting bioactive glass fibers to a plasma treatment; (2) dissolving chitosan in an aqueous acetic acid solution, and then adding the treated bioactive glass fibers thereto, so as to obtain a mixed solution I; (3) adding a bioactive glass powder to an aqueous sodium tripolyphosphate solution, and then subjecting same to ball milling, so as to obtain a mixed solution II; (4) gradually adding the mixed solution II to the mixed solution I while stirring same, continuously stirring same overnight after the addition is finished, and then conducting filtering and drying, so as to obtain modified glass fibers; and (5) mixing the modified glass fibers with polylactic acid particles, and then subjecting the resulting mixture to melt extrusion, so as to obtain a polylactic acid composite material. In the present invention, by compounding modified bioactive glass fibers with a polylactic acid material, the mechanical strength of the composite material can be significantly improved.

The invention discloses an environment-triggered memristor with a nonvolatile storage function and a preparation method thereof, and the method comprises the steps: 1, adding polymer matrix powder with a hydrophilic group into an acetic acid solution, stirring to obtain a polymer matrix solution, taking inorganic salt with a moisture absorption characteristic, adding the inorganic salt into the polymer matrix solution, carrying out ultrasonic treatment, and filtering to obtain a polymer matrix solution; a precursor solution is obtained; 2, cleaning and blow-drying the flexible PI film with the ITO conductive layer to obtain a clean substrate; 3, spin-coating the precursor solution on the surface of an ITO conducting layer of a clean substrate, airing and drying to form a high-salt doped polymer matrix layer on the surface of the ITO conducting layer; and 4, sequentially sputtering active metal and protective metal on the surface of the high-salt doped polymer matrix layer to respectively form an active metal layer and a metal protective layer, thereby obtaining the environment-triggered memristor with the nonvolatile storage function. According to the invention, the coupling of environment threshold sensing and nonvolatile storage is realized, and the environment adaptability and safety of the memristor are improved.

The invention relates to the technical field of biomedical materials, in particular to a COF heterojunction nanosphere with biomimetic mineralization and antibacterial functions and a preparation method and application thereof. The preparation method comprises the following steps: mixing a magnolol solution, a 1, 3, 5-tris (4-aminophenyl) benzene solution, a polyvinylpyrrolidone solution, a 2, 5-dimethoxybenzene-1, 4-dicarboxaldehyde solution and acetic acid, so as to obtain COFDMTP-coated Honokiol nanospheres; the preparation method comprises the following steps: mixing 4, 4 '-((2, 5-diformyl-1, 4-phenylene) bis (oxy)) dibutyric acid, COFDMTP (at) Honokiol nanospheres, acetonitrile and an acetic acid solution, and reacting to obtain the COFFPBA (at) Honokiol heterojunction nanospheres. The heterojunction nanosphere provided by the invention not only can promote the mineralization of acid-etched enamel, but also can effectively inhibit the growth of oral bacteria and reduce the occurrence of decayed teeth.

The invention relates to the technical field of synthesis of chlorine-containing pyridine intermediates, and discloses a method for synthesizing 2, 3, 4, 5-tetrachloropyridine by using 2, 5-dichloropyridine, which comprises the following steps: step 1, preparation of 2, 5-dichloropyridine nitrogen oxide: taking 2, 5-dichloropyridine as a raw material, reacting in the presence of a catalyst and acetic acid, and then filtering to remove the catalyst to obtain 2, 5-dichloropyridine nitrogen oxide; adding an acetic acid solution of 2, 5-dichloropyridine nitrogen oxide; step 2, nitration reaction: adding sulfuric acid and nitric acid, and reacting to obtain 2, 5-dichloro-4-nitropyridine nitrogen oxide; step 3, nitrogen and oxygen removal reaction: adding acetyl chloride to replace 4-position nitro to obtain 2, 4, 5-trichloropyridine nitrogen oxide, and then adding phosphorus trichloride to remove nitrogen and oxygen to obtain 2, 4, 5-trichloropyridine; and 4, chlorination and refining: adding Lewis acid into the 2, 4, 5-trichloropyridine, reacting to obtain a 2, 3, 4, 5-tetrachloropyridine crude product, and refining the crude product to obtain the finished product 2, 3, 4, 5-tetrachloropyridine. The invention solves the problems of more byproducts and unsatisfactory product purity and yield in the prior art.

The application belongs to the technical field of food packaging film preparation, and provides a polysaccharide-based food antibacterial fresh-keeping packaging film with pH and enzyme dual response performance and a preparation method thereof, which comprises the following steps: soaking pre-cooled bacterial cellulose in a CaCl2 solution and a mineralizing solution containing sodium phytate and Na2HPO4 in sequence, oscillating mineralization, mechanically crushing the product after freeze-drying to obtain mineralized bacterial cellulose particles; covalently coupling papain and phytic acid PA to obtain an enzyme-PA conjugate; swelling beta-glucan in hot water, adding an enzyme-PA conjugate and a CAR ethanol mixture, adding 0.5M ZnCl2 dropwise after homogenization to obtain a response layer liquid; adding glycerol and mineralized bacterial cellulose particles to a chitosan acetic acid solution, homogenizing to obtain a film-forming liquid; taking the film-forming liquid to form a film by a flow casting method, pre-drying, spraying the response layer liquid, and finally drying to obtain the fresh-keeping film. The fresh-keeping film realizes physical barrier, pH and enzyme responsive release, and prolongs the shelf life of fresh meat.

The invention provides a carbon quantum dot and small nucleic acid nanocomposite, which is formed by wrapping the outer layer of a positively charged carbon quantum dot with negatively charged siRNA through electrostatic interaction, the carbon quantum dot is a histidine-doped chitosan quantum dot or arginine-doped chitosan quantum dot, chitosan is dissolved in an acetic acid solution, and the small nucleic acid and the chitosan are mixed to form the nanocomposite. The preparation method comprises the following steps: continuously adding amino acid, stirring until the amino acid is dissolved, treating for 6-8 hours at the temperature of 100-180 DEG C to obtain a mixture, cooling the mixture to room temperature, centrifuging, passing through a filter membrane with the pore diameter of 0.22-0.45 mu m, dialyzing the obtained filtrate in ultrapure water for 8-12 hours by using a dialysis bag with the MWCO value of 800-1000Da, freeze-drying the residual dialysate in the dialysis bag to obtain carbon quantum dots, mixing the carbon quantum dots with free siRNA, and performing freeze-drying on the carbon quantum dots to obtain the siRNA. Incubating at room temperature for 30 minutes to 1 hour to obtain a nano compound of the carbon quantum dots and the small nucleic acid; according to the invention, the drug stability and targeting effect can be improved.

The present application relates to the technical field of wound dressing, and particularly relates to a chitosan modified clay-based aerogel wound dressing and a preparation method thereof. The preparation method comprises the following steps: S1: adding clay minerals into deionized water to prepare a slurry, and adding acetic acid while stirring to obtain a clay mineral slurry; S2: dissolving chitosan in an acetic acid solution to prepare a chitosan sol; S3: continuously stirring and mixing the clay mineral slurry and the chitosan sol to obtain a sol; S4: immersing the sol in a metal cation solution first, and then immersing the sol in an anion salt solution to obtain a standing product; and S5: freeze-drying the standing product to obtain a composite aerogel. The present application successfully constructs a three-dimensional porous aerogel dressing, which not only retains the strong hemostatic ability of clay, but also significantly enhances the mechanical strength and antibacterial performance, and exhibits great potential in the treatment of high-exudation complex wounds such as diabetic foot ulcers and infected wounds.

This invention belongs to the field of carbon dot technology in traditional Chinese medicine, and more specifically, relates to cinnamon carbon quantum dots, composite films, their preparation methods, and applications. The cinnamon carbon quantum dots provided by this invention are prepared from cinnamon as raw material through a hydrothermal reaction at 190–210℃ for 9–11 hours, followed by centrifugation and dialysis (molecular weight cutoff 900–1100 Da). The resulting particles are spherical with a particle size of 1.5–3.2 nm and contain O-C=O, C-O, and C-C functional groups on their surface. A composite film is prepared by mixing and drying chitosan, acetic acid solution, glycerol, and the cinnamon carbon quantum dot solution. This composite film, when used for preserving honeysuckle berries, can improve the rate of good fruit, reduce weight loss, and maintain nutritional indicators such as soluble solids, titratable acid, total phenols, ascorbic acid, anthocyanins, and flavonoids. Simultaneously, it reduces malondialdehyde content, inhibits respiration intensity, and maintains fruit firmness. It extends the shelf life by 4 days at 25℃ and by 10 days at 4℃, demonstrating promising application prospects in fruit and vegetable preservation.

The invention discloses a compound color fixing agent and a preparation method and application thereof, and belongs to the technical field of papermaking chemicals, the preparation method of the compound color fixing agent comprises the following steps: adding a bio-based polycation component into an acetic acid solution, heating and stirring to obtain a bio-based polycation stock solution; and adding amphiphilic polycyclodextrin and a surfactant into the bio-based polycation stock solution, and carrying out homogenization treatment to obtain the compound color fixing agent. The compound color fixing agent provided by the invention comprises bio-based polycations, amphiphilic polycyclodextrin and a surfactant, the amphiphilic polycyclodextrin with a hydrophobic cavity is connected with C3-C5 alkyl and quaternary ammonium salt groups, through a multi-component compounding design, by utilizing a synergistic effect of host-guest inclusion, electrostatic interaction and hydrophobic interaction, the color fixing agent has a good color fixing effect, and the color fixing agent has a good color fixing effect. And a coating with an interpenetrating network structure is constructed on the surface of the paper, so that fixation of the dye is realized.

This invention discloses a method for preparing and applying a chitosan-nanofibrillar-based smart indicator membrane loaded with anthocyanins and alizarin. The method includes the following steps: mixing beet powder with hydrochloric acid, washing with water until neutral, and drying; adding sodium hydroxide solution, mixing and reacting, washing with water until neutral, and drying; adding sodium chlorite solution, mixing, adjusting the pH to 3-3.5, reacting, and washing with water until neutral to obtain beet fiber; adding water, homogenizing under ultra-high pressure to obtain a beet nano-suspension; adding the beet nano-suspension to a chitosan-acetic acid solution and stirring, then adding glycerol; adding pigments, mixing, and obtaining a membrane solution; ultrasonically degassing, and drying to form a membrane. This membrane, as a food preservation indicator membrane, possesses both the characteristics and functions of food preservation and indicating food freshness; using beet nanofibers as a supplementary material improves the mechanical properties of the chitosan membrane; the addition of alizarin and anthocyanin mixed pigments enriches the color changes of the indicator membrane and improves its stability.

The invention provides antibacterial hydrogel artificial skin and a preparation method thereof, and belongs to the technical field of 3D printing biomaterials, the antibacterial hydrogel artificial skin is prepared from the following raw materials by weight: 1-3 parts of aluminum chloride hexahydrate, 30-45 parts of water, 15-22 parts of graft modified chitosan, 8-15 parts of acrylamide, and 1-3 parts of N, N-dimethylformamide. The coating comprises the following components in parts by weight: 0.2-0.8 part of N, N '-methylene bisacrylamide, 0.5-1.5 parts of a photoinitiator, 6-12 parts of quaternized chitosan and 4-8 parts of nano-hydroxyapatite. Wherein the graft modified chitosan is prepared from the following raw materials: 5 to 10 parts of chitosan, 80 to 120 parts of acetic acid solution with the concentration of 2 percent, 0.8 to 2.5 parts of glycidyl methacrylate and 0.05 to 0.2 part of azodiisobutyronitrile. According to the application, by adopting a formula taking the grafted modified chitosan as a core, a collaborative design of multi-scale crosslinking and personalized 3D printing is formed, high mechanical strength, broad-spectrum long-acting bacteriostasis, precise form adaptation and excellent biocompatibility of the hydrogel are realized, and the clinical complex wound repair requirements are met.

This invention relates to a method for preparing a biomass-based biodegradable dust suppressant and a spraying device, comprising the following components by weight percentage: 0.78% biomass matrix, 20.7% salt-precipitating solution, and the remainder being an acetic acid solution diluted with deionized water. The specific steps are as follows: adding biomass matrix powder to the acetic acid solution; pouring the salt-precipitating solution powder into the biomass matrix acetic acid solution; magnetically stirring for 30 minutes at 200 r / min and 30°C; and then sonicating for 10 minutes to ensure a complete reaction. This invention combines salt-precipitation with dust suppression technology, using high-concentration salt solutions such as sodium citrate and sodium sulfate. Utilizing the physicochemical interaction between salt ions and biomass material molecules, and through the synergistic effect of salt-precipitation-assisted precipitation and weak ion cross-linking, it breaks the limitations of traditional cross-linking methods, promoting the rapid formation of a three-dimensional network structure, thereby constructing a high-strength hydrogel membrane. This method allows for the simple and convenient preparation of a long-lasting and safe dust suppressant, effectively improving dust suppression efficiency and reducing dust suppression costs.

The invention relates to the technical field of degradable high polymer materials and disposable personal care products, and discloses a preparation process of a degradable high-barrier plastic film for a hair dyeing shawl, and the preparation process comprises the following steps: 1, preparing chitosan-dopamine grafted modified montmorillonite (CTS-DA-MMT): dispersing 5g of 20-30nm nano montmorillonite in a 2wt% acetic acid solution, and ultrasonically dispersing for 40 minutes by 200W; adding dopamine hydrochloride according to the ratio of montmorillonite to dopamine being 1: 0.2, adjusting the pH value to 8.5 by using 1mol / L NaOH, and carrying out stirring reaction at room temperature for 1 hour; adding chitosan according to the ratio of montmorillonite to chitosan being 1: 0.4, and stirring and reacting at the constant temperature of 50 DEG C for 3 hours; the pH is adjusted to 7.0 through 1 mol / L HCl, centrifugation is carried out for 15 min at the speed of 8000 r / min, washing is carried out three times through deionized water, vacuum drying is carried out for 8 h at the temperature of 60 DEG C, and the product is obtained. According to the preparation technology of the high-barrier plastic film for the degradable hair dyeing shawl, chemical grafting (instead of physical blending) of montmorillonite-dopamine-chitosan is achieved through catechol groups of dopamine, the problems of montmorillonite agglomeration and matrix compatibility are solved, and the degradable hair dyeing shawl is prepared. Meanwhile, through the dynamic adhesiveness of dopamine, the problem of barrier failure under dynamic stretching is solved.

The invention relates to the technical field of nitrogen-containing graphene, in particular to a method for preparing nitrogen-containing graphene by taking chitosan as a raw material, which comprises the following steps: dissolving chitosan in an acetic acid solution with the concentration of 3-5% to form a mixed solution, uniformly coating the mixed solution on the surface of a quartz base material by adopting a spin-coating technology, and under a nitrogen protection environment, preparing the nitrogen-containing graphene by taking the chitosan as the raw material. Slowly heating the base material coated with the mixed solution to 200-3500 DEG C, and annealing for 2 hours to obtain a chitosan film; then carrying out two-step carbonization to obtain a pre-carbonized product; and uniformly mixing the obtained pre-carbonized product with a regulation agglomeration agent, carrying out two-step activation treatment, and after the activation is completed, carrying out post-treatment on the product to obtain a nitrogen-containing graphene product. The nitrogen-containing graphene prepared by the method has a D / G ratio of 0.87 and a 2D / G ratio of 0.71, has few defects and has a good layered crystal structure, and the dielectric constant of a nitrogen-containing graphene device prepared subsequently is only 3.53.

The invention discloses a preparation method of a self-crosslinking injectable dual-network OXG-CS-Gel composite hydrogel, which comprises the following steps: dissolving oxidized xanthan gum in ultrapure water to obtain an oxidized xanthan gum solution, dissolving gelatin in ultrapure water to obtain a gelatin solution, dissolving chitosan in an acetic acid solution, stirring at room temperature until complete dissolution to obtain a chitosan solution, and carrying out freeze drying to obtain the self-crosslinking injectable dual-network OXG-CS-Gel composite hydrogel. The preparation method comprises the following steps: adding a chitosan solution into an oxidized xanthan gum solution, uniformly stirring to obtain an OXG-CS solution, then adding a gelatin solution, uniformly stirring to obtain an OXG-CS-Gel solution, and standing to form gel to obtain OXG-CS-Gel composite hydrogel; the composite hydrogel obtained by the invention is formed by a dynamic Schiff base bond and a hydrogen bond, has excellent self-crosslinking capability, self-healing performance, injectable performance and swelling performance, overcomes the defects that the traditional hydrogel is complex in gelling process, needs a cross-linking agent for cross-linking and the like; and a new material is provided for the fields of minimally invasive injection, wound healing, hemostatic materials, targeted drug delivery and the like.

The invention discloses a magnetic amide functionalized covalent organic framework material and a preparation method and application thereof, the preparation method comprises the following steps: S1, uniformly dispersing Fe3O4 nanoparticles and ammonia water, adding tetraethyl orthosilicate, and reacting; s2, a product obtained in the step S1 and 3-aminopropyltriethoxysilane are uniformly dispersed and subjected to a reaction, and aminated magnetic nanoparticles Fe3O4 (at) SiO2-NH2 are obtained; and S3, uniformly dispersing the Fe3O4 (at) SiO2-NH2 and trialdehyde phloroglucinol in a mixed solution of o-dichlorobenzene and N, N-dimethylformamide, adding 4, 4 '-diaminobenzanilide, uniformly mixing, then adding an acetic acid solution, and reacting at the temperature of 100-120 DEG C for 3-5 days to obtain the magnetic covalent organic framework Fe3O4 (at) Am-COFs material. The Fe3O4atAm-COFs prepared by the preparation method disclosed by the invention has a large specific surface area, rapid magnetic separation capability and abundant active sites, so that the adsorption performance of the material on a target object is effectively improved.

The application provides a synthesis method of 6-bromo-2-chloro-3-nitropyridine and relates to the technical field of organic synthesis. 2-amino-3-nitro-6-chloropyridine is reacted with a hydrobromic acid acetic acid solution to obtain 2-amino-3-nitro-6-bromopyridine, which is diazotized to obtain 6-bromo-2-hydroxy-3-nitropyridine, and then the 6-bromo-2-hydroxy-3-nitropyridine is reacted with a chlorinating reagent to obtain 6-bromo-2-chloro-3-nitropyridine. The synthesis method of 6-bromo-2-chloro-3-nitropyridine has the advantages of easy availability of raw materials, low price, mild reaction condition, simple process, high economic benefit, suitability for large-scale production, and the like, can solve the current situation of high price of 6-bromo-2-chloro-3-nitropyridine, and can play a positive role in the promotion of downstream products of 6-bromo-2-chloro-3-nitropyridine.

This invention provides a pH-responsive, high-temperature resistant hybrid intelligent drug-release microcapsule, its preparation method, and its application in electrical insulation materials, relating to the field of electrical insulation materials. The preparation method of the microcapsules of this invention includes the following steps: weighing chitosan and adding it to an aqueous acetic acid solution, stirring to obtain an acidic chitosan solution; adding an isothiazolinone antibacterial agent solution dropwise to the acidic chitosan solution, performing high-speed shearing and ultrasonic dispersion to obtain a nano / submicron emulsion; adding tetraethyl orthosilicate dropwise to the emulsion, stirring, adjusting the pH value to form a hybrid gel shell; dispersing the hybrid gel shell in anhydrous ethanol; adding a silane coupling agent; adding a zinc salt solution, stirring to obtain a microcapsule slurry; adding the microcapsule slurry to a growth solution, and reacting to obtain the target microcapsules. The microcapsules of this invention have a core-shell-skin three-layer structure and, when used in outdoor electrical insulation materials, can achieve intelligent response and long-term inhibition of algae, mold, and microbial attachment and growth.

The invention belongs to the technical field of mineral processing treatment, and particularly discloses porous magnesium oxide based on dolomite and a macro-quantity preparation method of the porous magnesium oxide. The method comprises the following steps: crushing dolomite ore, and carrying out solid-phase reaction on the crushed dolomite ore and ammonium dihydrogen phosphate to obtain a mixture containing MgNH4PO4 and calcium phosphate; then selectively dissolving out magnesium in the mixture by using an acetic acid solution to obtain magnesium-rich filtrate and calcium hydrophosphate filter residues; mixing the magnesium-rich filtrate with ammonium bicarbonate for reaction to obtain basic magnesium carbonate precipitate and an ammonia-containing solution; sequentially carrying out first heat treatment and second heat treatment on the basic magnesium carbonate precipitate to obtain the porous magnesium oxide. According to the method, the porous magnesium oxide is successfully prepared on a large scale by taking the dolomite with large reserves and low cost as a direct raw material; the porous magnesium oxide also has the advantages of hierarchical pore structure and large specific surface area.

The invention relates to an evaluation method of a building material mortar mix proportion, and belongs to the technical field of building materials. The evaluation method comprises the following steps: drying a to-be-detected sample to constant weight, weighing the initial mass m0 of the sample, putting the sample into a high-temperature furnace, calcining, and weighing the mass m1 of the sample; grinding the calcined sample in a mortar, so that a hydration product adhered to the sand is separated; the ground sample is placed on a sieve to be screened, the mass of oversize products and the mass of undersize products are weighed, the oversize products are recorded as m2, and the undersize products are recorded as m3; soaking oversize products with an acetic acid solution, stirring and cleaning the oversize products on a sieve, drying the oversize products to constant weight, recording the weight as m4, combining the mass lost by pickling with m3, and recording the combined mass as m5; and calculating the value of the sand-glue ratio m4 / m5, comparing with a design value, and judging whether the sand-glue ratio is qualified or not. According to the invention, the aggregate and the cementing material of the mortar subjected to hydration reaction after construction can be effectively separated, the mortar-to-sand ratio of the mortar for construction can be accurately calculated, and whether the mortar is qualified or not can be judged.