380 results about "Triethylenetetramine" patented technology

The invention discloses a method for preparing graphene aerogel and application thereof, and relates to the technical field of graphene materials. The method includes steps of uniformly mixing graphene oxide dispersion liquid and amine curing agents with one another to obtain graphene oxide mixed liquid; hermetically heating the obtained graphene oxide mixed liquid to obtain the graphene aerogel. The amine curing agents are one type of or a plurality of types of diaminodiphenyl-methane, diamino diphenyl sulfone, diethylenetriamine, triethylenetetramine, diethylaminopropylamine and m-phenylenediamine. The graphene aerogel prepared by the aid of the method can be applied to epoxy resin, so that graphene aerogel / epoxy resin composite materials with high conductivity and excellent mechanical properties can be obtained. The method and the application have the advantages that the graphene aerogel prepared by the aid of the method is internally of a uniform macroporous structure and is high in porosity; the amine curing agents are adopted in preparation procedures, accordingly, the epoxy resin interface bonding can be improved, and the conductivity and the mechanical properties of the epoxy resin can be enhanced.

A composition including triethylenetetramine and aminoethylpiperazine is used as a clay inhibitor in water-based drilling fluids and in hydraulic fracturing fluids for drilling wells and for fracturing subterranean formations, and is also used as a clay inhibitor in other treatment fluids for treating wells or subterranean formations.

The invention relates to a preparation method and application of an amphoteric chelate sorbent containing agricultural straw. The sorbent is brownish-yellow solid powder, the nitrogen content is 10.83wt%, and the specific surface area is 12.93m<2> / g. The sorbent is prepared by taking agricultural straw, epoxy chloropropane and monochloroacetic acid as raw materials, taking trimethylamine or triethylamine as a grafting reaction agent and taking ethylenediamine, diethylenetriamine or triethylenetetramine as a cross-linking agent. The method of the invention has the advantages of simple production processes, economy, practicability, reproducibility and the like and can be suitable for large-scale production. The sorbent prepared by the invention has the characteristics of good stability, good adsorption effect, wide application range and the like, can be widely applied to treatment of waste water containing heavy metal ions, and has better treatment effect.

The invention relates to a preparation method of a formaldehyde-free color fixative. The invention is characterized in that amines and epoxy chloropropane react to generate a condensate, wherein the amines are total amines and prepared by mixing hexamethylendiamine and other substances; and the other substances can be one or more of ammonia water, monomethyl amine, dimethyl amine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, tetraethylenepentamine, ethylene diamine, urea and urea substitute. The color fixative has the advantages of high color fastness, small influence on sensitive color tone, low consumption, no environment pollution of formaldehyde, accessible raw materials and simple production technique, can enhance the dry / wet fastness to rubbing and the color fastness to water washing, and basically does not generate color phase variations when fixing emerald blue, bright blue and other sensitive color dyes.

The invention discloses a method for removing carbon dioxide from a gas mixture through biphasic absorption. In the method, an organic solution of enamine is used as an absorbent, wherein the enamine is one or more of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine and hexvinylhepamino; an organic solvent is one or more of C1-C10 alcohols, tetrahydrofuran, DMF and DMAC; the absorbent has the characteristics of large absorption amount and high absorption speed. The carbon dioxide in the gas mixture is removed by generating precipitate after being contacted with the absorbent, the absorbent is regenerated for desorption after the precipitate is obtained through separation, and desorbed liquid is reused in an absorption process; the method has the advantages of low regeneration temperature, and significant decrease in regeneration energy consumption.

The invention discloses a metal wear resistant repairing composite coating material and a preparation method of the metal wear resistant repairing composite coating material, wherein the metal wear resistant repairing composite coating material comprises a main agent which is prepared by mixing a silane coupling agent, epoxy resin, diisoamyl naphthalene, silicon carbide particles, aluminium oxide powder and fumed silica, and a curing agent which is prepared by mixing a silane coupling agent, triethylenetetramine, N-aminoethyl piperazine, aluminium oxide powder and fumed silica. A two-component room temperature curing composite coating with good anti-corrosion performance and abrasive resistance is prepared by optimizing the performance of epoxy coating inorganic powder filled and modified with inorganic powder, the prepared wear-resistant coating has good bonding effect to the metal, the cured coating has excellent abrasive resistance and can be applied for building and repairing the inner layer of a liquid slurry delivery pump, and an anti-corrosion wear-resistant coating of blades, and building an anti-corrosion wear-resistant coating of the inner surface of a gas transmission pipeline, a powder transmission pipeline and a liquid transmission pipeline.

The invention relates to a biological adhesive for plywood and a preparation method thereof. The adhesive is a product obtained by chemically modifying animal blood protein grains with an amino compound and epoxy chloropropane, and the weight ratio of animal blood protein grains to amino compound to epoxy chloropropane is 10:1-5:1-5, wherein the animal blood protein grains are prepared from fresh animal blood, the grain size is greater than or equal to 50 meshes, and the solid content is 60-95 wt%; the amino compound is one or more than one of ammonia water, dimethylamine, diethylenetriamine, triethylenetetramine, polyvinylamine, polyethyleneimine and polyketoamine; and the fresh animal blood is blood of pigs, cows, sheep, chickens or ducks. The preparation method comprises the following steps of: chemically modifying the animal blood protein grains with the amino compound and epoxy chloropropane, and diluting the product to obtain the biological adhesive. The obtained adhesive reaches the bonding strength of No. I adhesives, the water resistance of an adhesive layer is increased, and the adhesive does not contain formaldehyde and has low cost and industrial popularization value.

A substantially cyanide-free plating solution for depositing copper from the monovalent ionic state, which includes a source of copper ions, a reducing agent capable of reducing divalent copper ions to monovalent copper ions, an alkali material in an amount sufficient to maintain the pH of the solution in the range of about 7 to about 10, and a complexing agent of an imide, such as succinimide, 3-methyl-3-ethyl succinimide, 3-methyl succinimide, 3-ethyl succinimide, 3,3,4,4-tetramethyl succinimide, or 3,3,4-trimethyl succinimide, or a hydantoin, such as dimethyl hydantoin. The substantially cyanide-free plating solutions may also include at least one of a conductivity salt, an additive to promote brightness, or an alloying metal. The reducing agent may be an alkali sulfite, alkali bisulfite, hydroxylamine, or hydrazine. The copper is typically provided in the form of CuC1, CuC12, CuSO4, or Cu20 in an amount sufficient to provide a copper ion concentration of from about 2 to about 30 grams per liter of solution, and the complexing agent is present in an amount sufficient to provide a molar ratio of copper ions to complexing agent of from about 1:1 to about 1:5, preferably about 1:4. The alkali material is typically NaOH, KOH, NH4OH, or Na2CO3, and the conductivity salt is typically NaC1, KC1, Na2SO4, K4P2O7, Na3PO4, C6H5Na3O7, C6H11NaO7, NH4C1, or KNaC4H4O6. Useful additives include organic amines or oxyalkyl polyamines, such as triethylene tetramine, tetraethylene pentamine, and polyoxypropyl-triamine. Methods for preparing such a solution for plating copper onto a substrate, and of plating copper onto a substrate with such a solution are also disclosed.

To provide a technique for realizing high-precision surface planarization when copper is used as a wiring metal. A polishing compound is used which comprises water; a peroxide oxidizer; a surface protective agent for copper; at least one first chelating agent selected from the group consisting of tartaric acid, malonic acid, malic acid, citric acid, maleic acid, oxalic acid and fumaric acid; and at least one second chelating agent selected from the group consisting of triethylenetetramine, ethylenediaminediacetic acid, ethylenediaminetetraacetic acid, tetraethylenepentamine, glycol-ether-diaminetetraacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, o-phenanthroline, and derivatives thereof.

Preparation and application of water-soluble macromolecule heavy-metal collector belong to the technical field of preparation of functional macromolecule materials and treatment of heavy-metal-containing waste water. The invention discloses a preparation method of the water-soluble macromolecule heavy-metal collector. The preparation method includes generating a macromolecule framework by crosslinking micromolecule amine ethylenediamine with triethylenetetramine, and grafting dithio carbamic acid group on the macromolecule framework to generate the water-soluble macromolecule heavy-metal collector. The like heavy-metal collector has effects of chelating heavy-metal ions and netting flocculation, can react with the free or complexing heavy-metal ions quickly in waste water at the normal temperature to generate insoluble precipitations, and is applicable to wide range of heavy-metal ions, the flocculation precipitation is large in particles, compact in structure and fast in settlement, the pH value ranges from 1 to 9, and removal rate of the heavy-metal ions in water is high and can reach above 95%.

The invention relates to an environment-friendly external wall paint containing shell powder, which is prepared from the following raw materials in parts by weight: 60-80 parts of shell powder, 40-60 parts of pure acrylic emulsion, 30-50 parts of styrene-acrylic emulsion, 5-10 parts of surfactant, 5-10 parts of hydroxypropyl methyl cellulose, 5-10 parts of aluminum hydroxide, 10-20 parts of calcium oxide, 3-5 parts of magnesium silicate, 5-10 parts of zeolite powder, 5-10 parts of polyvinyl alcohol, 1-5 parts of nanometer calcium carbonate, 1-2 parts of titanium pigment, 1-3 parts of polyethylene glycol, 1-3 parts of turpentine, 1-3 parts of chitosan, 1-3 parts of triethylenetetramine, 0.1-1 part of sodium fluoride, 0.1-0.5 part of water silicon oil, 1-3 parts of defoamer, 1-3 parts of dispersant, 3-5 parts of propylene glycol and 30-50 parts of de-ionized water. The environment-friendly external wall paint provided by the invention contains multiple kinds of specific components which play a mutual synergy effect, so that the prepared paint has the advantages of good wear resistance, strong adhesive force, ageing resistance, acid and alkali resistance as well as a function of removing formaldehyde, and the paint is green and environment-friendly, non-toxic and harmless to human body and wide in market prospects.

The invention relates to a high-efficiency desulfurizing combined solvent which is characterized by having extremely high absorption selectivity on an SO2 gas and higher velocity on the absorption and desorption of the SO2 gas. The high-efficiency desulfurizing combined solvent concretely comprises the following components: a first component, a second component and a third component, wherein the first component is a mixture or any single substance of substances, namely N-methyl pyrrolidone or dimethyl sulfoxide and the like, and the weight percent of the first component accounts for 0.1%-50% of the combined solvent; the second component a mixture or any single substance of polyamine, namely ethylene diamine, propane diamine, diethylenetriamine, triethylenetetramine, and the like which at least contain two amine groups, and piperazine, and the weight percent of the second component accounts for 0.1%-50% of the combined solvent; the third component is the balance of the combined solvent and contains a mixture or any single substance of other acids, namely phosphoric acid, boracic acid, citric acid, and the like, and water; the pH value of the combined solvent is regulated to 5-8. The high-efficiency desulfurizing combined solvent disclosed by the invention is low in volatility without waste gas and waste liquor discharge, can be recycled for multiple times by being desorbed and regenerated, can be used for desorbing the (dry basis) SO2 gas with the purity of 99% and is suitable for being used as an absorbent of the SO2 gas contained in a power plant waste gas.

Amphoteric derivatives of aliphatic polyamines, such as diethylenetriamine or triethylenetetramine reacted with long chain fatty acids, esters or triglycerides from various natural or synthetic sources are effective in the softening / texture modification of substrates such as paper, textiles, human skin surfaces and hair tresses, as well as in applications for metal working and lubrication. The polyamines are first reacted with fatty acids, esters or triglycerides derived from various animal, vegetable or synthetic sources ranging in molecular distribution from butyric through erucic acids (e.g. milkfat, soy bean oil, rapeseed oil) to form polyamines or imidazolines; they are then further reacted with unsaturated or halogenated carboxylic acids, carboxylated epoxy compounds or acid anhydrides (e.g. acrylic acid, itaconic acid, chloroacetic acid, maleic anhydrides octadecenyl anhydride) to form the various amphoteric structures.

The invention provides an electroless copper plating activating solution and a preparation method thereof. The electroless copper plating activating solution is prepared from, by weight part, 1-10 parts of palladium chloride, 100-400 parts of stannous chloride, 50-200 parts of sodium chloride, 10-100 parts of sodium chloride, 0.1-50 parts of a complexing agent, 1-200 parts of a buffering agent, 0.1-10 parts of a stabilizing agent, 0.05-10 parts of an antioxidant and 0.1-10 parts of a wetting agent. The complexing agent is one or more of ethidene diamine, trimethyl amine, triethylanmine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine. The buffering agent is one or more of ethylenediamine tetraacetic acid, glycine, propionic acid, malic acid and 2-(cyclohexylamino)ethanesulfonic acid. The electroless copper plating activating solution is high in stability and can adapt to intense circulating stirring in a horizontal electroless copper plating process.

The invention discloses an epoxy resin composition which comprises an epoxy resin and a curing agent, wherein the general formula of the epoxy resin is disclosed as Formula (I). In the Formula (I), A is disclosed in the specification, and n=2-8. The curing agent is at least one of ethylenediamine, hexamethylendiamine, cyclohexamethylendiamine, diethylenetriamine and triethylenetetramine. The invention also discloses a wet-process ultrasonic degradation method of an epoxy resin curing substance prepared by mixing and curing the epoxy resin composition, which comprises the following steps: pulverizing the epoxy resin curing substance prepared by mixing and curing the epoxy resin and curing agent, mixing with a non-proton polar solvent, swelling, and carrying out ultrasonic degradation treatment to obtain the soluble high polymer. The method has the advantages of mild degradation conditions and high efficiency, and can implement regeneration and recycling of the epoxy resin.

Disclosed herein is a method for separating an arsenic mineral from a copper-bearing material, including the steps of grinding a copper-bearing material containing arsenic, adding water to the copper-bearing material to prepare a slurry, and adding a flotation agent including a depressant, a frother, and a collector to the slurry and blowing air into the slurry for performing flotation to obtain a copper concentrate, wherein the depressant is a chelator. As the chelator, a polyethyleneamine or the like is used. Particularly, when triethylenetetramine is used as the chelator, the amount of triethylenetetramine to be added is preferably 1 to 10 equivalents relative to the amount of soluble copper generated by oxidation of the copper-bearing material, and the pH of the slurry is more preferably adjusted to 7 or more but 8 or less before the slurry is subjected to the flotation.

The invention discloses a method for preparing a polyamine-epichlorohydrin color fixing agent. The color fixing agent is obtained by controlling the mixing ratio of triethylenetetramine or tetraethylenepentamine or a mixture of the triethylenetetramine and the tetraethylenepentamine, epichlorohydrin, triethylamine and distilled water, and the parameters of hybrid reaction. The color fixing agent is used for dyeing after-treatment of textiles, can improve the washing fastness and color fastness to dry and wet crocking of the dyeing of various anionic dyes and keep the handfeel of the textiles soft, and solves the problem that a color fixing agent prepared by the conventional method has bad effects of fixing the colors of fabrics such as dark cotton fabrics, silk, wool, nylon and the like.

The invention provides a cross-linked polyacrylonitrile-based amidoxime fiber. A method for preparing the cross-linked polyacrylonitrile-based amidoxime fiber includes steps of (1), carrying out cross-linking on polyacrylonitrile fibers by the aid of triethylenetetramine to obtain cross-linked polyacrylonitrile fibers; (2), carrying out amidoximation on the cross-linked polyacrylonitrile fibers obtained at the previous step by the aid of hydroxylammonium chloride to obtain the cross-linked polyacrylonitrile-based amidoxime fiber. The cross-linked polyacrylonitrile-based amidoxime fiber and the method have the advantages that the problem that common amidoxime fibers cannot be directly applied to Bayer solution for extracting gallium can be effectively solved; the cross-linked polyacrylonitrile-based amidoxime fiber is high in mechanical strength and high in gallium adsorption capacity and selectivity and has a broad market prospect.

The invention provides a depressurization and augmented injection scale inhibitor for a low-permeation water injection well and a preparation method of the depressurization and augmented injection scale inhibitor. The depressurization and augmented injection scale inhibitor is prepared from the following raw materials: 10-12 parts of a nonionic surfactant, 18-20 parts of a triethylenetetramine-N,N,N',N'',N''',N'''-hexaacetic acid hexasodium salt, 5-8 parts of an anionic surfactant, 6-8 parts of an organic phosphonocarboxylic acid scale inhibitor, 2-5 parts of a dispersant, 15-18 parts of a diluents, 8-10 parts of an organic amine salt and 30-36 parts of water. The depressurization and augmented injection scale inhibitor for the low-permeation water injection well has the characteristic of multiple efficacy with one dose, is good in effects of swelling resistance, swelling shrinkage, corrosion inhibition and calcium sulfate and barium (strontium) sulfate scale inhibition when the dosage is 0.5 percent of water injection rate of the water injection well and barium sulfate solubility is improved by 3125 times at the temperature being 60 DEG C.

The invention provides a preparation method for a China-hemp antibacterial fiber material. The preparation method comprises the following steps: (1) reacting China-hemp fibrils with a base to obtain alkalized China-hemp fibers; (2) oxidizing the alkalized China-hemp fibers with an oxidizing agent to obtain oxidized China-hemp fibers; (3) reacting the oxidized China-hemp fibers with triethylenetetramine to obtain aminated China-hemp fibers; and (4) reacting the aminated China-hemp fibers with glycidyl trimethylammonium halide to obtain the China-hemp antibacterial fiber material containing a quaternary ammonium anti-bacterial functional group. According to the invention, the quaternary ammonium anti-bacterial functional group is covalently grafted into a China-hemp fiber skeleton structure,so the China-hemp antibacterial fibers are allowed to contain the quaternary ammonium antibacterial functional group and have excellent antibacterial properties, no toxicity to human beings, long-lasting antibacterial action and stable performance. The preparation method of the invention is simple in process, easy to opera and control, and friendly to environment. At the same time, the fibers obtained after the reactions are free of pungent amine smell, have good shape and mechanical strength, and can be applied to the development of various antibacterial functional textiles and the sterilization of industrial and domestic water.

The invention relates to a preparation method of an epoxy resin-based micro-filtration film. Firstly, under a certain temperature, the epoxy resin and amines such as diethylene triamine or triethylenetetramine is completely dissolved in polyethyleneglycol medium by a certain weight ratio, and the air bubble is then removed; the solution is cast or flow-cast on supporting material such as metal or plastic tape, and suitable temperature is kept. After a certain time, monomer solution generates polymerization and phase separation at the same time; gel is solidified as white epoxy resin-based nascent state film; the nascent state film is finally dipped in water, and the medium polyethyleneglycol is removed to obtain the micro-filtration film. Other organic solvents are not required to be added in the preparation process, with green environmental protection. The prepared micro-filtration film has good mechanical strength, uniform distribution of aperture, adjustable size, strong hydrophilicity, acid resistance, alkali resistance and solvent resistance; furthermore, the structure of the film is not damaged by high-temperature germicidal treatment under the temperature of 120 DEG C; the film has excellent performance and the method of the invention can be widely applied to the separation and filtration in the industries such as instrument analysis, water disposal and biological medicine, etc.

A water-addition-type surfactant-based composition, containing: at least one of a fatty acid sodium salt and / or potassium salt, as a surfactant component; and at least one of N,N-bis(carboxymethyl)-L-glutamic acid tetrasodium salt, L -aspartate-(N,N)-diacetic acid tetrasodium salt, N-2-hydroxyethyliminodiacetic acid disodium salt, (S,S)-ethylenediaminesuccinic acid trisodium salt, methylglycinediacetic acid trisodium salt, ethylenediaminetetraacetic acid, nitorilotriacetic acid, diethylenetriaminepentaacetic acid, hydroxyethylethylenediaminetriacetic acid, triethylenetetraminehexaacetic acid, 1,3-propanediaminetetraacetic acid, 1,3-diamino-2-hydroxypropanetetraacetic acid, dihydroxyethylglycine, glycol ether diamine tetraacetic acid, hydroxyethanediphosphonic acid, aminotrimethylenephosphonic acid, 1,2,4-butanetricarboxylic acid, dihydroxyethylethylenediaminediacetic acid, sodium gluconate, sodium glucoheptonate, inositol hexaphosphate, hydroxyethanoic acid, 2-hydroxypropanoic acid, 2-hydroxysuccinic acid, 2,3-dihydroxybutanedioic acid, and 2-hydroxy-1,2,3-propanetricarboxylic acid, as a chelating component.

The invention relates to a high-adhesion-strength low-temperature curing conductive silver adhesive used for a piezoelectric composite material and a preparation method of the adhesive. The conductivesilver adhesive includes a conductive filler, basic resin, a curing agent and a solvent, wherein the conductive filler is conductive silver powder, the basic resin is epoxy resin, and the curing agent is an organic polyamine curing agent. The additive can further include an additive, and the additive is one or more selected from a diluent, a dispersant, a toughening agent, a coupling agent, a catalyst, a conductive accelerator, a curing accelerator, and an adhesion accelerator. The organic polyamine curing agent is one selected from ethylenediamine, tetraethylenepentamine, triethanolamine, diethylenetriamine, and triethylenetetramine of fatty amines of single polyamines. The conductive silver adhesive provided by the invention has the advantages of low costs, a low curing temperature, short curing time, good electrical conductivity, and high adhesion strength between a silver layer and a composite material as well as high adhesion strength between the silver layer and a welding spot compared with that of a market, and can be widely used in the field of welding of the composite material.

In various aspects, the invention provides methods for treating ocular inflammation using copper chelating compounds, such as compounds other than D-penicillamine. In some embodiments, such compounds may be polyamines, such as triethylenetetramine or tetraethylenepentamine. For example, the present invention provides methods for treating inflammation secondary to ocular laser therapy.

The present invention discloses an adipic acid bis-imidazoline derivative and a preparation method thereof, and applications of the adipic acid bis-imidazoline derivative as a corrosion inhibitor. According to the present invention, the preparation method comprises that: adipic acid and triethylenetetramine react to generate an imidazoline intermediate, the imidazoline intermediate and benzyl chloride react to obtain a quaternization product, and the quaternization product and thiourea react to generate a target compound. According to the present invention, when the adipic acid bis-imidazoline derivative prepared by the method is adopted as the corrosion inhibitor, the excellent anti-CO2 corrosion performance is provided at the low temperature.

The invention discloses a composite additive and a preparation method thereof. The key points of the technical scheme adopted by the invention are as follows: the composite additive is characterized in that the composite additive is prepared by mixing several single additives with stronger polarities in percentage by weight: 80-99 percent of oxidation and corrosion inhibitor, 5-15 percent of triethylenetetramine, 0.5-1.5 percent of trisubstituted-octyl carbinol, 1-7 percent of antirust completing agent, 3-8 percent of benzotriazole, 0.5-1.5 percent of dinonylnaphthalene sulfonic acid barium and 5-10 percent of flame retardant. The raw materials are refined under certain conditions to form the compound additive. The composite additive can be used for producing lubricating grease. The lubricating grease prepared from the composite additive has more excellent performances of resisting water showering, extreme pressure, high temperature and the like compared with single additive. According to the preparation method, a formula of the raw materials is reasonable, the process is advanced and the cost of products can be reduced; and in addition, the prepared lubricating grease has excellent performances, and thus the produced lubricating grease products have higher sales advantages.

The invention relates to a method for inhibiting generation of grease in an alkaline tower, and mainly solves the problems that the alkaline tower is easy to block and is inconvenient for operation caused by poor grease inhibiting effect in a conventional technology. The technical solution of the method solves the problems well by employing on-line continuously injecting inhibitor, wherein the inhibitor is at least one selected from diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dipropylenetriamine, tripropylenetetramine, tetrapropylenepentamine. The method can be applied to alkaline towers of industrial apparatuses of preparing ethane from petroleum, preparing ethylene from ethanol, preparing alkene from methanol, and preparing propylene, vinyl acetate, dichloroethylene and epoxypropane from methanol, etc.

An amino-enhanced graphene membrane and a preparing method thereof are disclosed. The method includes (1) adding a mixture of a graphene oxide solution, a water-soluble amine type crosslinking agent and a water-soluble reductant into a flat-shape hollow reactor, with the water-soluble amine type crosslinking agent being one or more selected from a group consisting of ethylenediamine, diaminopropane, diaminobutane, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, ammonia, poly(allylamine) and para-phenylene diamine, and the water-soluble reductant being one or more selected from a group consisting of ascorbic acid, sodium ascorbate, sodium citrate, hydroiodic acid, hydrobromic acid, sodium hydrogen sulfite and sodium sulfide, (2) heating the reactor at 60-95 DEG C, and (3) drying amino-enhanced graphene hydrogel prepared in the step (2). A nitrogen-doped graphene membrane and a preparing method thereof are also disclosed. The nitrogen-doped graphene membrane is prepared by subjecting the amino-enhanced graphene membrane to heat processing. The methods are simple and mild in conditions, and the prepared graphene membranes are uniform in structure and excellent in mechanical properties.