CN102351172B - Method for preparing multilayer graphene - Google Patents

Abstract

The invention discloses a preparation method of multilayer graphene, which is characterized in that 85-98.5 parts of vinyl monomers, 1-10 parts of layered compounds and 0.5-5 parts of aromatization catalyst are firstly prepared according to the mass ratio, and then bulk polymerization is adopted. Or in-situ polymerization to prepare a vinyl polymer compound, then heat at 700-1500°C for 1min-10h under an inert atmosphere, and place the obtained mixture containing multi-layer graphene in a hydrogen fluoride with a mass concentration of 10-30% Soak in acid solution for 1-48h, then place the separated solid in a mixed solution of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 1:1 and soak for 1-48h, separate and obtain purified multilayer graphene with a thickness of 0.35-15nm . The method of the invention uses vinyl polymer as a carbon source, and the source of raw materials is abundant; the used aromatization catalyst can be directly obtained from the market; the reaction process is mild and controllable, and the operation is convenient; and low-cost large-scale preparation of graphene can be realized.

Description

A kind of preparation method of multilayer graphene

technical field

The invention belongs to the technical field of graphene material preparation, and in particular relates to a method for preparing multilayer graphene by using vinyl polymer as a carbon source and performing heat treatment under the action of a layered compound and an aromatization catalyst.

Background technique

Graphene nanomaterial is a carbon atomic structure with only one or several layers of atomic thickness, and its CC bonds are combined by SP ² to form a dense honeycomb lattice structure. Graphene's excellent electrical properties, good thermal conductivity, high Young's modulus and fracture strength, and some unique properties, such as quantum Hall effect, quantum tunneling effect, etc., make it widely used in gas sensors, energy storage and composite materials, etc. The field has bright application prospects. But graphene's current applications are limited by the lack of large-scale, low-cost production methods. The preparation method of existing graphene mainly contains: as introduced in Chinese Patent Application No. 201010179119.1, adopts mechanical exfoliation carbon material to obtain graphene, but the yield of mechanical exfoliation method is low and the mixed product that obtains graphene is difficult to separate; Chinese patent Although the epitaxial growth method introduced in application number 200910077648.8 can prepare single-layer graphene, it is difficult to obtain graphene with large area and uniform thickness due to the complex surface structure of SiC crystal; the arc method introduced in Chinese patent application number 200910312486.1 High energy requirement, often accompanied by by-products in the product, large-scale production is greatly limited; the graphite oxide reduction method introduced in Chinese Patent Application No. 200910099595.X first uses strong acid and strong oxidizing substances to oxidize natural graphite into graphite oxide, Then obtain graphene through hydrazine reduction, the preparation process of this method has the danger of explosion, the raw material used is more toxic and the graphene obtained has certain structural defects; the chemical vapor deposition method introduced in the application number 200810113596.0 can prepare high High-quality, large-area graphene, but the preparation process of the ideal substrate material required for the preparation of graphene is complex and expensive. So far, there has been no report on the preparation of graphene by directly using metal powder as a catalyst to catalyze the cracking of polymers at a certain temperature.

Contents of the invention

The purpose of the present invention is to provide a kind of preparation method of multi-layer graphene, to overcome the deficiencies such as complex preparation process and high cost existing in the existing graphene production process, to achieve low cost and large-scale production of graphene.

The preparation method of multilayer graphene of the present invention is characterized in that:

Prepare vinyl polymer composites first; then heat the prepared vinyl polymer composites at 700-1500°C for 1min-2h under an inert atmosphere with a flow rate of 50-1000ml/min to obtain multilayer graphene The mixture containing multilayer graphene is placed in a hydrofluoric acid solution with a mass concentration of 10-30% and soaked for 1-48h, and after separation, the resulting solid is placed in sulfuric acid with a mass concentration of 60-98% and mass concentration of 30-65% nitric acid are soaked in a mixed solution prepared at a volume ratio of 1:1 for 1-48h, and the purified multi-layer graphene is obtained after separation;

The method for preparing vinyl polymers is:

When the vinyl monomer is a styrene monomer, (meth)acrylate monomer, vinyl ester monomer or vinyl ether monomer, the method of bulk polymerization is adopted, that is, 85 - 98.5 parts of vinyl monomers and 0.085-4.925 parts of oil-soluble initiators are added with 1-10 parts of layered compounds and 0.5-5 parts of aromatization catalysts under the protection of an inert atmosphere and stirring, and the temperature is raised to 75-120 ° C for polymerization to The viscous and flowable prepolymer is then kept at 60-120°C for 12-72h to cure and form a vinyl polymer compound;

When the vinyl monomer is an acrylonitrile monomer, the method of solution polymerization is adopted, that is, 85-98.5 parts of vinyl monomer, 0.425-9.85 parts of water-soluble initiator and 85-394 parts of distilled water are mixed in Add 1-10 parts of layered compound and 0.5-5 parts of aromatization catalyst under inert atmosphere protection and stirring, heat up to 75-120°C to polymerize to a viscous flowable prepolymer, and then keep it at 80-150°C for 12- 72h, that is, curing to form a vinyl polymer compound;

Described styrene monomer, its structure can adopt general formula to be expressed as:

In the formula, X ₁ , X ₂ , X ₃ , X ₄ , X ₅ , X ₆ and X ₇ are H, CH ₃ , C _m H _2m+1 , OH, OCH ₃ , OC _m H _2m+1 , COOH, COOCH _3. COOC _m H _2m+1 , Cl or Br, X ₈ is H, CH ₃ or C _m H _2m+1 , m is an integer, n is 1-2; suitable monomers include: styrene, α-formaldehyde butylstyrene, tert-butylstyrene, o-, m- or p-methylstyrene, o-, m- or p-ethylstyrene, o-, m- or p-isopropylstyrene, p-chloro or bromostyrene, o, p-di Chlorine and bromostyrene, ortho, m or p-methoxystyrene, o, m or p-tert-butoxystyrene, o, m or p-phenoxystyrene, p-trimethylsiloxyindene and its derivatives, ethylene Naphthalene, vinylalkylnaphthalene, vinylhalogenated naphthalene, indenene, diphenylethylene or vinylanthracene;

The (meth)acrylate monomers include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, (meth) n-butyl acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, sec-butyl (meth)acrylate, n-pentyl (meth)acrylate, isoamyl (meth)acrylate, Cyclopentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, (meth)acrylate 2 - ethyl butyl, n-nonyl (meth)acrylate, n-decyl methacrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cinnamyl (meth)acrylate, ( Crotonyl methacrylate, N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, N,N-tert-butylethyl (meth)acrylate ester, 2-sulfoethyl (meth)acrylate, glycidyl (meth)acrylate, benzyl (meth)acrylate, allyl (meth)acrylate, 2-n-butoxy (meth)acrylate Ethyl ester, 2-fluoroethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, furfuryl (meth)acrylate, 2-methoxybutyl (meth)acrylate, ( 3-methoxybutyl methacrylate, 2-nitro-2-methylpropyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-phenoxy (meth)acrylate ethyl (meth)acrylate, 2-phenylethyl (meth)acrylate, phenyl (meth)acrylate, propargyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, bornyl (meth)acrylate or Tetrahydropyranyl (meth)acrylate;

The vinyl ester monomers include vinyl formate, vinyl acetate, vinyl propionate, vinyl caproate, vinyl octanoate, vinyl nonanoate, vinyl laurate, vinyl palmitate, vinyl stearate ester, vinyl valerate, vinyl monochloroacetate, vinyl trichloroacetate, vinyl trifluoroacetate, vinyl toluate or vinyl 2-ethylhexanoate;

The vinyl ether monomers include methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether or isobutyl vinyl ether;

The acrylonitrile monomer includes acrylonitrile, methacrylonitrile, 4-pentenenitrile, 3-methyl-4-pentenenitrile, 5-hexanenitrile, 4-vinyl-benzonitrile, 4-vinyl - cyclohexanenitrile or 4-cyanocyclohexene;

The oil-soluble initiator includes an azo compound selected from azobisisobutyronitrile, azobis(dimethylvaleronitrile), azobicyclohexylnitrile, dimethyl-2,2'-azobis Isobutyronitrile, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile); or a peroxide selected from benzoyl peroxide, lauroyl peroxide, peroxide Acetyl, octanoyl peroxide, isobutyl peroxide, cumyl peroxide neodecanoate, acetylcyclohexylsulfonyl peroxide, isopropyl peroxydicarbonate, n-butyl peroxydicarbonate, isopropyl peroxydicarbonate Butyl peroxydicarbonate, sec-butyl peroxydicarbonate, 2-ethylhexyl peroxydicarbonate, or tert-butyl peroxybenzoate;

Described water-soluble initiator comprises potassium persulfate, sodium persulfate, ammonium persulfate or hydrogen peroxide;

The layered compound includes organically modified montmorillonite, organically modified layered phosphate or organically modified double hydroxide;

Organically modified montmorillonites include organically modified sodium-based montmorillonites, organically modified calcium-based montmorillonites, organically modified calcium-magnesium-based montmorillonites, and organically modified iron-based montmorillonites Or organically modified nickel-based montmorillonite; the synthetic method of this iron-based or nickel-based montmorillonite is: the molar ratio of soluble metal iron salt or nickel salt, sodium silicate and magnesium acetate or zinc acetate is 1.4-1.9 : 3.8-4.2: 0.25-0.35 to prepare a solution, adjust the pH to 10.5-12.5, put it in an autoclave and react at 140-180°C for 12-72h to obtain iron-based or nickel-based montmorillonite; the organically modified montmorillonite The preparation method of desoiling is as follows: after mixing montmorillonite and cationic organic modifier at a mass ratio of 1:0.5-5, then adding it to distilled water at a liquid-to-solid mass ratio of 100ml/g, at 60-120°C Heat and stir for 4-48h, wash with distilled water until neutral, and obtain organically modified montmorillonite after separation; the cationic organic modifier is selected from dodecyltrimethylammonium chloride, dodecyltrimethylammonium Ammonium bromide, dodecyldimethylbenzyl ammonium chloride, dodecyldimethylbenzyl ammonium bromide, tetradecyldimethylbenzyl ammonium chloride, tetradecyldimethylbenzyl ammonium Benzyl ammonium bromide, cetyl trimethyl ammonium chloride, cetyl trimethyl ammonium bromide, octadecyl dimethyl benzyl ammonium chloride, octadecyl dimethyl benzyl Ammonium Bromide, Octadecyltrimethylammonium Chloride, or Octadecyltrimethylammonium Bromide;

The organically modified layered phosphate includes organically modified layered titanium phosphate, organically modified layered zirconium phosphate, organically modified layered hafnium phosphate, organically modified layered vanadium phosphate, organically modified Layered niobium phosphate, organically modified layered molybdenum phosphate, organically modified layered cerium phosphate, organically modified layered germanium phosphate, organically modified layered tin phosphate or organically modified layered lead phosphate The preparation method of the organically modified phosphate is as follows: after dissolving the soluble metal salt and phosphoric acid, mixing and stirring at a molar ratio of 1:2-5 to form a gel liquid, transferring the gel to a reaction kettle, and React at 150-200°C for 4-72 hours, wash with distilled water until neutral, and obtain layered phosphate after separation; disperse the powder of the layered phosphate in the aqueous solution to form a uniform suspension according to the liquid-solid mass ratio of 100ml/g , then add 0.2-0.5mol/l ethylamine solution dropwise to the suspension according to the molar ratio of ethylamine to phosphate is 2-4:1, ultrasonic 30-120min until a uniform colloidal solution is obtained, and then add phosphate 0.5-5 times the weight of a cationic organic modifier, ultrasonic 30-120min, washed with distilled water until neutral, and separated to obtain an organically modified phosphate; the cationic organic modifier is selected from dodecyl trimethyl Ammonium Chloride, Dodecyltrimethylammonium Bromide, Dodecyldimethylbenzylammonium Chloride, Dodecyldimethylbenzylammonium Bromide, Tetradecyldimethylbenzyl Ammonium Chloride, Tetradecyl Dimethyl Benzyl Ammonium Bromide, Cetyl Trimethyl Ammonium Chloride, Cetyl Trimethyl Ammonium Bromide, Octadecyl Dimethyl Benzyl Ammonium Chloride Ammonium, Octadecyldimethylbenzylammonium Bromide, Octadecyltrimethylammonium Chloride, or Octadecyltrimethylammonium Bromide;

The organically modified double hydroxides include organically modified magnesium-iron double hydroxides, organically modified calcium-iron double hydroxides, organically modified zinc-iron double hydroxides, organically modified ferromanganese Double hydroxide, organically modified cobalt-iron double hydroxide, organically modified nickel-iron double hydroxide, organically modified copper-iron double hydroxide, organically modified cobalt-aluminum double hydroxide, organic Modified nickel aluminum double hydroxide, organically modified cobalt chromium double hydroxide, organically modified nickel chromium double hydroxide, organically modified cobalt gallium double hydroxide or organically modified nickel gallium double hydroxide Hydroxide; the preparation method of the organically modified double hydroxide is: the molar ratio of divalent metal ions and trivalent metal ions is 1-5: 1, and the total concentration of metal ions is 0.1-2mol/l Aqueous solution; add an alkali solution with a molar concentration of 1-4mol/l dropwise under stirring at room temperature, adjust the pH to 7.5-12, then raise the temperature to 70-140°C, and add an anionic type with 0.5-5 times the molar mass of trivalent ions Organic modifier, react for 6-60h, wash with distilled water to neutrality, and obtain organically modified double hydroxide after separation; the anionic organic modifier is selected from sodium lauryl sulfate, dodecylsulfonic acid Sodium, sodium dodecylbenzenesulfonate, sodium dialkylbenzenesulfonate, sodium dodecylbenzenesulfonate, sodium butylnaphthalenesulfonate, sodium dibutylnaphthalenesulfonate, diisopropylnaphthalenesulfonate Sodium, sodium monobismethyl naphthalene sulfonate, or sodium lauryl sulfate;

The aromatization catalyst is selected from iron, cobalt, nickel, copper, palladium, platinum, ruthenium, manganese, chromium, molybdenum or tungsten, and its particle size is not greater than 500 μm;

The inert atmosphere usually adopts nitrogen, helium or argon atmosphere.

The invention utilizes layered compounds to block the cracked products of the graphitizable polymer in many micro-reaction zones, so that they can more fully contact the graphitization catalyst, thereby effectively converting into multi-layer graphene. Compared with the prior art, the method of the present invention has the following advantages: the preparation method of multilayer graphene of the present invention can use vinyl polymer as a carbon source, and its raw material source is abundant; the aromatization catalyst adopted can be obtained directly from the market The reaction process of the multilayer graphene of the present invention is mild and controllable, and the operation is convenient; the method of the present invention can realize low-cost and large-scale preparation of graphene, and the thickness of the obtained graphene sheet is distributed in the range of 0.35-15nm.

Description of drawings

Fig. 1 is the scanning electron micrograph of the multilayer graphene that makes in embodiment 1.

Fig. 2 is the transmission electron microscope picture of the multilayer graphene that makes in embodiment 2.

Fig. 3 is the high-resolution electron microscope picture of the multilayer graphene that makes in embodiment 2.

Fig. 4 is the Raman figure of the multilayer graphene that makes in embodiment 3.

Fig. 5 is the X-ray photoelectron energy spectrogram of the multilayer graphene that makes in embodiment 4.

Fig. 6 is the thermogravimetric graph of the multilayer graphene that makes in embodiment 6.

Detailed ways

Example 1:

After mixing sodium montmorillonite and cetyltrimethylammonium bromide in a mass ratio of 1:1, add it into distilled water at a liquid-solid mass ratio of 100ml/g, heat and stir at 80°C for 12h Centrifuge, wash with distilled water until neutral, and dry to obtain organically modified sodium-based montmorillonite.

In a three-necked flask equipped with a stirrer, 92.5 parts of styrene and 0.46 parts of benzoyl peroxide are charged according to the mass ratio, and 5 parts of organically modified sodium-based montmorillonite are added to the three-necked flask under nitrogen protection and stirring. Soil and 2.5 parts of iron are heated to 85°C to polymerize to a viscous flowable prepolymer, and then placed in an oven at 70°C for 24 hours to solidify into a polystyrene compound. It was then heated at 900° C. for 10 min under a nitrogen atmosphere with a flow rate of 200 ml/min. The resulting mixture containing multi-layer graphene is added with a mass concentration of 30% hydrofluoric acid, soaked for 24h, and after separation, the resulting solid is added with a mass concentration of 98% sulfuric acid and 65% nitric acid by volume. In the mixed solution prepared at 1:1, soak for 12 hours, and obtain purified multilayer graphene after separation.

Fig. 1 has provided the scanning electron micrograph of the product that makes in the present embodiment, and product is piled up to form bird's nest structure by intertwined graphene sheet, and the diameter of graphene sheet is distributed in 400nm-3 μ m, and thickness is distributed in 0.35-15nm . The yield of the graphene sheet is not lower than 15%, has few defects and impurities, and is suitable for large-scale production.

Example 2:

After mixing sodium montmorillonite and cetyltrimethylammonium bromide at a mass ratio of 1:2, add it to distilled water at a liquid-solid mass ratio of 100ml/g, heat and stir at 80°C for 48h Centrifuge, wash with distilled water until neutral, and dry to obtain organically modified sodium-based montmorillonite.

In a three-necked flask equipped with a stirrer, load 92.5 parts of styrene and 4.925 parts of benzoyl peroxide according to the mass ratio, and add 5 parts of organically modified sodium-based montmorillonite to the flask under nitrogen protection and stirring and 2.5 parts of copper, heated to 85°C to polymerize to a viscous flowable prepolymer, and then placed in an oven at 80°C for 12 hours to solidify into a polystyrene compound. It was then heated at 1000° C. for 15 minutes under a nitrogen atmosphere with a flow rate of 100 ml/min. The obtained mixture containing multi-layer graphene is added with a mass concentration of 30% concentrated hydrofluoric acid, soaked for 48h, and after separation, the obtained solid is added with a mass concentration of 98% sulfuric acid and a mass concentration of 30% nitric acid by volume. In the mixed solution prepared at 1:1, soak for 24 hours, and obtain purified multilayer graphene after separation.

Figure 2 and Figure 3 show the transmission electron microscope and high resolution transmission electron microscope images of the graphene prepared in this embodiment, respectively. It can be seen from the TEM images that the graphene sheets are stacked on each other, and the sidewalls are rolled up at the edges, and the thickness of the graphene is distributed between 0.35nm and 6nm. The thickness of the graphene shown in the high-resolution electron microscope image is 3-8 atomic layers, and the crystallization degree of graphene is high.

Example 3:

Ferric chloride, sodium silicate and zinc acetate were formulated into a solution at a molar ratio of 1.4:3.8:0.25, adjusted to pH 12.5, and placed in an autoclave at 140°C for 72 hours to obtain iron-based montmorillonite. After mixing the above-mentioned iron-based montmorillonite and octadecyldimethylbenzyl ammonium bromide in a ratio of 1:0.5 by mass ratio, it was added to distilled water at a liquid-solid mass ratio of 80ml/g at 120 After heating and stirring at ℃ for 4 hours, centrifuge, wash with distilled water until neutral, and obtain organically modified iron-based montmorillonite after drying.

In a three-necked flask equipped with a stirrer, 88 parts of methyl methacrylate and 0.264 parts of benzoyl peroxide are charged according to the mass ratio, and 8 parts of organically modified iron are added to the flask under nitrogen protection and stirring. Based on montmorillonite and 4 parts of copper, the temperature is raised to 80°C for polymerization to obtain a viscous flowable prepolymer, and then put into an oven at 65°C for 48 hours to solidify into a polymethyl methacrylate compound. It was then heated at 1000° C. for 5 minutes under a nitrogen atmosphere with a flow rate of 1000 ml/min. The obtained mixture containing multi-layer graphene is added into a mass concentration of 10% hydrofluoric acid solution, soaked for 24h, and after separation, the resulting solid is added with a mass concentration of 60% sulfuric acid and a mass concentration of 65% nitric acid by volume. Soak in the mixed solution prepared for 1:1 for 36h, and obtain purified multilayer graphene after separation.

Fig. 4 has provided the Raman figure of the graphene that makes in the present embodiment, can find out from the figure, the ratio of G band and D band is about 0.6, and this shows that the graphene crystallization degree that makes is high, and defect few. In addition, the existence of a 2D peak can also be observed at ²⁷⁰⁰ cm, which fully proves the formation of graphene.

Example 4:

Nickel acetate, sodium silicate, and zinc acetate were formulated into a solution at a molar ratio of 1.9:4.2:0.35, adjusted to pH 10.5, and placed in an autoclave at 180°C for 12 hours to obtain nickel-based montmorillonite. Mix the above-prepared nickel-based montmorillonite and dodecyltrimethylchloride in a mass ratio of 1:5, add it to distilled water at a liquid-solid mass ratio of 80ml/g, and heat and stir at 60°C After 48 hours, it was centrifuged, washed with distilled water until neutral, and dried to obtain organically modified nickel-based montmorillonite.

In a three-necked flask equipped with a stirrer, put 85 parts of methyl acrylate and 0.085 parts of azobisisobutyronitrile according to the mass ratio, and add 10 parts of organically modified nickel-based montmorillonite into the flask under nitrogen protection and stirring. Remove the soil and 5 parts of copper, heat up to 75 ° C to polymerize to a viscous flowable prepolymer, and then put it in an oven at 60 ° C for 72 hours to solidify into a polymethylacrylate compound. It was then heated at 950° C. for 20 min under argon at a flow rate of 200 ml/min. The resulting mixture containing multi-layer graphene is added into a 20% hydrofluoric acid solution with a mass concentration of 20%, soaked for 36 hours, and after separation, the resulting solid is added with a mass concentration of 98% sulfuric acid and 65% nitric acid by volume. Soak in the mixed solution prepared at 1:1 for 48h, and obtain purified multilayer graphene after separation.

Fig. 5 has provided the X-ray photoelectron energy spectrogram of the graphene that makes in the present embodiment, can find out, the carbon atom content is about 94.6% in the graphene, and the content of oxygen atom is about 5.4%, illustrates using polyformaldehyde The graphene obtained by using methyl acrylate as a carbon source contains only a very small amount of heteroatom defects.

Example 5:

Dissolve 0.5mol of zirconium oxychloride in 1000ml of distilled water, then add 1mol of phosphoric acid solution with a mass concentration of 85%, stir to form a gel, transfer the gel to a reaction kettle, react at 150°C for 72h, and wash with distilled water Until the solution is neutral, dry to obtain layered zirconium phosphate; the powder of this layered zirconium phosphate is dispersed in the aqueous solution according to the liquid-solid mass ratio of 100ml/g, and then the molar ratio of ethylamine to layered zirconium phosphate is 2: 1 Add 0.5 mol/l ethylamine solution dropwise to the uniformly dispersed suspension, perform interlayer pre-stretching, obtain a uniform colloidal solution after ultrasonication for 30 minutes, and then add hexadecane which is 0.5 times the mass of layered zirconium phosphate Trimethylammonium bromide was further intercalated by ultrasonication for 120min, centrifuged, washed with distilled water until neutral, and dried to obtain organically modified layered zirconium phosphate.

In a flask equipped with a stirrer, put 98.5 parts of 2-phenoxyethyl methacrylate and 0.085 parts of tert-butyl peroxybenzoate according to the mass ratio, and add 1 part of Organically modified layered zirconium phosphate and 0.5 parts of tungsten are heated up to 120°C to polymerize to a viscous and flowable prepolymer, and then placed in an oven at 120°C for 12 hours to solidify into polymethacrylic acid 2-phenoxy Ethyl complexes. It was then heated at 1500° C. for 1 min under helium at a flow rate of 50 ml/min. The resulting mixture containing multi-layer graphene is added with a mass concentration of 30% hydrofluoric acid, soaked for 1h, and after separation, the resulting solid is added with a mass concentration of 60% sulfuric acid and a mass concentration of 30% nitric acid. In the mixed solution prepared at 1:1, soak for 1 h, and obtain purified multilayer graphene after separation.

Embodiment 6:

Dissolve 0.5 mol of titanium tetrachloride in 1000 ml of distilled water, then add 2.5 mol of phosphoric acid solution with a mass concentration of 85%, stir to form a gel, transfer the gel to a reaction kettle, react at 200°C for 4 hours, and use distilled water Wash until the solution is neutral and dry to obtain layered titanium phosphate; the powder of the layered titanium phosphate is dispersed in the aqueous solution according to the liquid-solid mass ratio of 100ml/g, and then the molar ratio of ethylamine to layered titanium phosphate is 4 : 1 the ethylamine solution of 0.2mol/l is added dropwise to the uniformly dispersed suspension, it is pre-supported between layers, obtains a uniform colloid solution after ultrasonic 120min, and then adds 18% by layered titanium phosphate quality 5 times Alkyltrimethylammonium chloride was further intercalated by ultrasonication for 30 minutes, centrifuged, washed with distilled water until neutral, and dried to obtain organically modified layered titanium phosphate.

In a flask equipped with a stirrer, charge 94 parts of vinyl acetate and 0.47 parts of benzoyl peroxide according to the mass ratio, and add 4 parts of organically modified layered titanium phosphate to the flask under argon protection and stirring and 2 parts of nickel, the temperature is raised to 90°C to polymerize to a viscous flowable prepolymer, and then placed in an oven at 70°C for 24 hours to solidify into a polyvinyl acetate compound. It was then heated at 700° C. for 2 h at a flow rate of 200 ml/min argon. The resulting mixture containing multi-layer graphene is added with a mass concentration of 30% hydrofluoric acid, soaked for 10h, and after separation, the resulting solid is added with a mass concentration of 60% sulfuric acid and a mass concentration of 30% nitric acid. In the mixed solution prepared at 1:1, soak for 24h, and obtain purified multilayer graphene after separation.

Figure 6 shows the thermogravimetric curve of the graphene prepared in this example in air. Graphene begins to decompose at 550°C, reaches its peak weight loss at about 680°C, and maintains at least 4% of its weight at 1000°C. Residual weight, which shows that the obtained graphene has a high degree of crystallinity and few impurities and defects.

Embodiment 7:

Zinc nitrate and aluminum nitrate are formulated into an aqueous solution with a total metal ion concentration of 2 mol/l at a molar ratio of 1:1; an alkali solution with a molar concentration of 1 mol/l is added dropwise under stirring at room temperature to adjust the pH to 12, and then Raise the temperature to 70°C, add sodium dodecyl sulfate which is 5 times the molar weight of trivalent ions to modify the product, react for 60 hours, centrifuge the precipitate, wash with distilled water until neutral, and obtain organically modified zinc after drying Aluminum double hydroxide.

In a flask equipped with a stirrer, 85 parts of acrylonitrile, 0.425 parts of potassium persulfate and 85 parts of water are charged according to the mass ratio, and 10 parts of organically modified zinc-aluminum dihydrogen are added to the flask under nitrogen protection and stirring. Oxide and 5 parts of nickel are heated up to 75°C to polymerize to a viscous and flowable prepolymer, and then placed in an oven at 80°C for 72 hours to solidify into a polyacrylonitrile compound. It was then heated at 1100° C. for 30 min under nitrogen at a flow rate of 400 ml/min. The resulting mass concentration of the mixture containing multi-layer graphene added is 30% hydrofluoric acid, soaked for 24h, and after separation, the resulting solid is added with a mass concentration of 98% sulfuric acid and a mass concentration of 65% nitric acid by volume. In the mixed solution prepared at 1:1, soak for 24 hours, and obtain purified multilayer graphene after separation.

Embodiment 8:

Nickel nitrate and ferric nitrate are formulated into an aqueous solution with a total concentration of metal ions of 0.1 mol/l at a molar ratio of 5:1; an alkali solution with a molar concentration of 4 mol/l is added dropwise under stirring at room temperature to adjust the pH to 7.5, Then heat up to 140°C, add sodium dodecylbenzenesulfonate 0.5 times the molar weight of trivalent ions to modify the product, react for 6 hours, centrifuge the precipitate, wash with water until neutral, and obtain organic modification after drying nickel-iron double hydroxide.

In a flask equipped with a stirrer, 98.5 parts of acrylonitrile, 9.85 parts of ammonium persulfate and 394 parts of water are charged according to the mass ratio, and 1 part of organically modified nickel-iron dihydrogen is added to the flask under nitrogen protection and stirring. Oxide and 0.5 parts of iron are heated up to 120°C to polymerize to a viscous and flowable prepolymer, and then placed in an oven at 150°C for 12 hours to solidify into a polyacrylonitrile compound. It was then treated at 900° C. for 1 h under nitrogen at a flow rate of 500 ml/min. The resulting mass concentration of the mixture containing multi-layer graphene added is 10% hydrofluoric acid, soaked for 36h, and after separation, the resulting solid is added with a mass concentration of 60% sulfuric acid and a mass concentration of 30% nitric acid by volume. In the mixed solution prepared at 1:1, soak for 6 hours, and obtain purified multilayer graphene after separation.

The styrene, methyl methacrylate, methyl acrylate, 2-phenoxyethyl methacrylate, vinyl acetate and acrylonitrile used in the above examples belong to vinyl monomers, if the vinyl monomers are replaced Similar results can be obtained for the following substances: styrenic monomers such as styrene, α-methylstyrene, tert-butylstyrene, o-, m-, or p-methylstyrene, ortho, m-, or p-ethylstyrene , o, m or p-isopropylstyrene, p-chloro or bromostyrene, o, p-dichloro and bromostyrene, o, m or p-methoxystyrene, o, m or p-tert-butoxystyrene, o-, m- or p-phenoxystyrene, p-trimethylsiloxyindene and its derivatives, vinylnaphthalene, vinylalkylnaphthalene, vinylhalogenated naphthalene, indenene, diphenylethylene and vinylanthracene; ( Methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate , tert-butyl (meth)acrylate, sec-butyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, cyclopentyl (meth)acrylate, (meth) n-hexyl acrylate, cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylbutyl (meth)acrylate, n-nonyl (meth)acrylate Esters, n-decyl methacrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cinnamyl (meth)acrylate, crotyl (meth)acrylate, N (meth)acrylate , N-dimethylaminoethyl ester, N,N-diethylaminoethyl (meth)acrylate, N,N-tert-butylethyl (meth)acrylate, 2-sulfoethyl (meth)acrylate, Glycidyl (meth)acrylate, benzyl (meth)acrylate, allyl (meth)acrylate, 2-n-butoxyethyl (meth)acrylate, 2-fluoroethyl (meth)acrylate ester, 2-ethoxyethyl (meth)acrylate, furfuryl (meth)acrylate, 2-methoxybutyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, ( 2-nitro-2-methylpropyl methacrylate, 2-ethylhexyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, 2-phenylethyl (meth)acrylate ester, phenyl (meth)acrylate, propargyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, bornyl (meth)acrylate or tetrahydropyranyl (meth)acrylate; vinyl Ester monomers such as vinyl formate, vinyl acetate, vinyl propionate, vinyl caproate, vinyl caprylate, vinyl nonanoate, vinyl laurate, vinyl palmitate, vinyl stearate, t-amyl Vinyl monochloroacetate, vinyl trichloroacetate, vinyl trifluoroacetate, vinyl toluate or vinyl 2-ethylhexanoate; vinyl ether monomers such as methyl vinyl ether, ethyl Vinyl ether, butyl vinyl ether or isobutyl vinyl ether; acrylonitrile monomers such as acrylonitrile, methacrylonitrile, 4-pentenenitrile, 3-methyl-4-pentenenitrile, 5-hexanonitrile , 4-vinyl-benzonitrile, 4-vinyl-cyclohexanenitrile or 4-cyano Cyclohexene;

Organically modified sodium-based montmorillonite, organically modified iron-based montmorillonite, organically modified nickel-based montmorillonite, organically modified layered zirconium phosphate, organically modified layered titanium phosphate, Organically modified zinc-aluminum double hydroxides and organically modified nickel-iron double hydroxides belong to layered compounds. If the layered compounds are replaced by the following substances, similar results can be obtained: organically modified sodium-based montmorillonite, Organically modified calcium-based montmorillonite, organically modified calcium-magnesium-based montmorillonite, organically modified iron-based montmorillonite, or organically modified nickel-based montmorillonite; organically modified layered titanium phosphate , organically modified layered zirconium phosphate, organically modified layered hafnium phosphate, organically modified layered vanadium phosphate, organically modified layered niobium phosphate, organically modified layered molybdenum phosphate, organically modified Layered cerium phosphate, organically modified layered germanium phosphate, organically modified layered tin phosphate or organically modified layered lead phosphate; organically modified magnesium iron double hydroxide, organically modified calcium iron double hydroxide Hydroxide, organically modified zinc-iron double hydroxide, organically modified manganese-iron double hydroxide, organically modified cobalt-iron double hydroxide, organically modified nickel-iron double hydroxide, organically modified Copper-iron double hydroxide, organically modified cobalt-aluminum double hydroxide, organically modified nickel-aluminum double hydroxide, organically modified cobalt-chromium double hydroxide, organically modified nickel-chromium double hydroxide oxide, organically modified cobalt gallium double hydroxide or organically modified nickel gallium double hydroxide; wherein the corresponding organic modifier of montmorillonite, layered phosphate can be selected from dodecyl trihydroxide Methyl ammonium chloride, dodecyl trimethyl ammonium bromide, dodecyl dimethyl benzyl ammonium chloride, dodecyl dimethyl benzyl ammonium bromide, tetradecyl dimethyl ammonium bromide Benzyl ammonium chloride, tetradecyl dimethyl benzyl ammonium bromide, cetyl trimethyl ammonium chloride, cetyl trimethyl ammonium bromide, octadecyl dimethyl benzyl Ammonium chloride, octadecyldimethylbenzylammonium bromide, octadecyltrimethylammonium chloride or octadecyltrimethylammonium bromide; corresponding organic modifier for double hydroxide Can be selected from sodium lauryl sulfate, sodium dodecylsulfonate, sodium dodecylbenzenesulfonate, sodium dialkylbenzenesulfonate, sodium dodecylbenzenesulfonate, sodium butylnaphthalenesulfonate , sodium dibutylnaphthalenesulfonate, sodium diisopropylnaphthalenesulfonate, sodium monodimethylnaphthalenesulfonate or sodium lauryl sulfate;

The iron, nickel and copper used in the above examples belong to the aromatization catalyst, if the aromatization catalyst is replaced by cobalt, palladium, platinum, ruthenium, manganese, chromium, molybdenum or tungsten, similar results can also be obtained.

Benzoyl peroxide, tert-butyl peroxybenzoate and azobisisobutyronitrile used in the above-mentioned examples belong to oil-soluble initiators, if oil-soluble initiators are replaced by: azobisisobutyronitrile, diisobutyronitrile Azobis(dimethylvaleronitrile), azobicyclohexylnitrile, dimethyl-2,2'-azobisisobutyronitrile, 2,2'-azobis(4-methoxy-2, 4-dimethylvaleronitrile); or lauroyl peroxide, acetyl peroxide, octanoyl peroxide, isobutyl ether peroxide, cumyl peroxide neodecanoate, acetylcyclohexylsulfonyl peroxide, isopropyl butyl peroxydicarbonate, n-butyl peroxydicarbonate, isobutyl peroxydicarbonate, sec-butyl peroxydicarbonate, 2-ethylhexyl peroxydicarbonate or tert-butyl peroxydicarbonate Butyl ester; described potassium persulfate and ammonium persulfate belong to water-soluble initiator, if water-soluble initiator is replaced by following material, all can obtain similar result: potassium persulfate, sodium persulfate, ammonium persulfate or hydrogen peroxide , similar results can be obtained.

Claims (9)

1. the preparation method of a multi-layer graphene is characterized in that:

The mixture for preparing vinyl polymer earlier by the method for mass polymerization or solution polymerization; Be 700-1500 ℃ of heating 1min-2h under the inert atmosphere of 50-1000ml/min again at flow with the mixture of prepared vinyl polymer, obtain containing the mixture of multi-layer graphene; It is that the hydrofluoric acid solution of 10-30% soaks 1-48h that this mixture that contains multi-layer graphene is placed mass concentration, after the separation resultant solid placed with the mass concentration be the sulfuric acid of 60-98% and nitric acid that mass concentration is 30-65% by volume for the mixing solutions of 1:1 preparation soaks 1-48h, namely obtain the multi-layer graphene of purifying after the separation;

The method of the mixture of described preparation vinyl polymer is:

Adopt styrene monomer, (methyl) acrylic ester monomer, vinyl ester monomer or vinyl ethers monomer to carry out mass polymerization as vinyl monomer, that is: press mass ratio 85-98.5 part vinyl monomer and 0.0085-9.85 part oil-soluble initiator are added 1-10 part lamellar compound and 0.5-5 part aromatized catalyst at inert atmosphere protection with under stirring, be warming up to 75-120 ℃ and be polymerized to the thickness performed polymer that can flow, at 60-120 ℃ of insulation 12-72h, namely solidify to form the mixture of vinyl polymer then; Perhaps

Adopt the vinyl cyanide monomer to carry out solution polymerization as vinyl monomer, that is: press mass ratio 85-98.5 part vinyl monomer, 0.0085-9.85 part water soluble starter and 85-394 part distilled water are added 1-10 part lamellar compound and 0.5-5 part aromatized catalyst at inert atmosphere protection with under stirring, be warming up to 75-120 ℃ and be polymerized to the thickness performed polymer that can flow, at 80-150 ℃ of insulation 12-72h, namely solidify to form the mixture of vinyl polymer then;

Layered compound is selected from organically-modified polynite, organically-modified layered phosphates or organically-modified double-hydroxide;

Described aromatized catalyst chosen from Fe, cobalt, nickel, copper, palladium, platinum, ruthenium, manganese, chromium, molybdenum or tungsten, its granularity size is not more than 500 μ m.

2. the preparation method of multi-layer graphene according to claim 1, be characterised in that described styrene monomer is selected from vinylbenzene, alpha-methyl styrene, t-butyl styrene, adjacent, between or p-methylstyrene, adjacent, between or to ethyl styrene, adjacent, between or p-isopropyl vinylbenzene, to chlorine or bromine vinylbenzene, the neighbour, right-dichloro and bromstyrol, adjacent, between or to methoxy styrene, adjacent, between or to tert.-butoxy vinylbenzene, adjacent, between or to phenoxy group vinylbenzene, to trimethylsiloxy group indenes and derivative, vinylnaphthalene, the vinyl alkylnaphthalene, the vinyl naphthalene halide, indenes alkene, diphenylethlene or vinyl anthracene.

3. the preparation method of multi-layer graphene according to claim 1, be characterised in that described (methyl) acrylic ester monomer is selected from (methyl) methyl acrylate, (methyl) ethyl propenoate, (methyl) vinylformic acid n-propyl, (methyl) isopropyl acrylate, (methyl) n-butyl acrylate, (methyl) isobutyl acrylate, (methyl) tert-butyl acrylate, (methyl) sec-butyl acrylate, (methyl) vinylformic acid n-pentyl ester, (methyl) vinylformic acid isopentyl ester, (methyl) vinylformic acid ring pentyl ester, the just own ester of (methyl) vinylformic acid, (methyl) cyclohexyl acrylate, the positive heptyl ester of (methyl) vinylformic acid, (methyl) vinylformic acid n-octyl, (methyl) vinylformic acid 2-ethyl butyl ester, (methyl) vinylformic acid ester in the positive ninth of the ten Heavenly Stems, methacrylic acid ester in the positive last of the ten Heavenly stems, (methyl) vinylformic acid Lauryl Ester, (methyl) stearyl acrylate base ester, (methyl) vinylformic acid cinnamic ester, (methyl) vinylformic acid crotons ester, (methyl) vinylformic acid N, the N-dimethylaminoethyl, (methyl) vinylformic acid N, the N-lignocaine ethyl ester, (methyl) vinylformic acid N, N-tertiary butyl ethyl ester, (methyl) vinylformic acid 2-sulphur ethyl ester, (methyl) glycidyl acrylate, (methyl) benzyl acrylate, (methyl) allyl acrylate, (methyl) vinylformic acid 2-n-butoxy ethyl ester, (methyl) vinylformic acid 2-fluoroethyl ester, (methyl) vinylformic acid 2-ethoxy ethyl ester, (methyl) vinylformic acid chaff ester, (methyl) vinylformic acid 2-methoxyl group butyl ester, (methyl) vinylformic acid 3-methoxyl group butyl ester, (methyl) vinylformic acid 2-nitro-2-methyl propyl ester, (methyl) 2-EHA, (methyl) vinylformic acid 2-phenoxy ethyl, (methyl) vinylformic acid 2-phenethyl ester, (methyl) phenyl acrylate, (methyl) vinylformic acid alkynes propyl ester, (methyl) tetrahydrofurfuryl acrylate, (methyl) vinylformic acid norbornene ester or (methyl) vinylformic acid tetrahydropyrans ester.

4. the preparation method of multi-layer graphene according to claim 1 is characterised in that described vinyl ester monomer is selected from vinyl formate, vinyl-acetic ester, propionate, vinyl caproate, sad vinyl acetate, n-nonanoic acid vinyl acetate, vinyl laurate, palmitinic acid vinyl acetate, stearic acid vinyl ester, trimethylacetic acid vinyl acetate, Monochloro Acetic Acid vinyl acetate, trichoroacetic acid(TCA) vinyl acetate, vinyl trifluoroacetate, toluic acid vinyl acetate or 2 ethyl hexanoic acid vinyl acetate.

5. the preparation method of multi-layer graphene according to claim 1 is characterised in that described vinyl ethers monomer is selected from ethylene methacrylic ether, ethyl vinyl ether, butyl vinyl ether or isobutyl vinyl ether.

6. the preparation method of multi-layer graphene according to claim 1 is characterised in that described vinyl cyanide monomer is selected from vinyl cyanide, methacrylonitrile, allyl acetonitrile, 3-methyl-allyl acetonitrile, the own nitrile of 5-, 4-vinyl-benzonitrile, 4-vinyl-cyclohexanenitrile or 4-cyanocyclohexanoic alkene.

7. the preparation method of multi-layer graphene according to claim 1, be characterised in that described oil-soluble initiator is selected from Diisopropyl azodicarboxylate, azo two (methyl pentane nitrile), azo two cyclohexanenitriles, dimethyl-2,2 '-Diisopropyl azodicarboxylate, 2,2 '-azo two (4-methoxyl group-2,4-methyl pentane nitrile); Or benzoyl peroxide, lauroyl peroxide, acetyl peroxide, peroxidation decoyl, peroxidation ethyl isobutyl ether, peroxidation neodecanoic acid isopropyl phenyl ester, acetyl peroxide cyclohexyl sulphonyl, sec.-propyl peroxide two carbonic ethers, normal-butyl peroxide two carbonic ethers, isobutyl-peroxide two carbonic ethers, sec-butyl peroxide two carbonic ethers, 2-ethylhexyl peroxide two carbonic ethers or peroxidized t-butyl perbenzoate.

8. the preparation method of multi-layer graphene according to claim 1 is characterised in that described water soluble starter is selected from Potassium Persulphate, Sodium Persulfate, ammonium persulphate or hydrogen peroxide.

9. the preparation method of multi-layer graphene according to claim 1 is characterised in that described organically-modified polynite comprises organically-modified sodium-based montmorillonite, organically-modified calcium-base montmorillonite, organically-modified calcium-magnesium base montmorillonite, organically-modified iron-based polynite or organically-modified ni montmorillonite; This organically-modified polynite preparation method is: be polynite and cationic organic modifiers to be that 100ml/g joins in the distilled water after the mixed of 1:0.5-5, by liquid-solid mass ratio by mass ratio, at 60-120 ℃ of heated and stirred 4-48h, distilled water wash obtains organically-modified polynite to neutral after the separation; This cationic organic modifiers is selected from Dodecyl trimethyl ammonium chloride, Trimethyllaurylammonium bromide, dodecyl benzyl dimethyl ammonium chloride, dodecyl dimethyl benzyl ammonium bromide, the tetradecyl dimethyl benzyl ammonium chloride, tetradecyl dimethyl benzyl ammonium, palmityl trimethyl ammonium chloride, cetyl trimethylammonium bromide, stearyl dimethyl benzyl ammonium chloride, octadecyl dimethyl benzyl brometo de amonio, octadecyl trimethyl ammonium chloride or octadecyl trimethylammonium bromide;

Described organically-modified layered phosphates comprises organic modified layered titanium phosphate, organically-modified bedded zirconium phosphate, organically-modified stratiform phosphoric acid hafnium, organically-modified lamellar vanadium phosphate, organically-modified stratiform niobium phosphate, organically-modified stratiform molybdenum phosphate, organically-modified stratiform Cerium monophosphate, organically-modified stratiform phosphoric acid germanium, organically-modified stratiform phosphoric acid tin or organically-modified stratiform lead phosphate; This organically-modified method for production of phosphate salt is: after soluble metallic salt and phosphoric acid dissolving, mixed with mol ratio 1:2-5 stirs the formation coagulant liquid, this gel is transferred in the reactor, at 150-200 ℃ of reaction 4-72h, be washed with distilled water to neutrality, obtain layered phosphates after the separation; To be 100ml/g with the powder of this layered phosphates be scattered in becomes uniform suspension in the aqueous solution by liquid-solid mass ratio, being 2-4:1 by ethamine and phosphoric acid salt mol ratio again is added drop-wise to the ethylamine solution of 0.2-0.5mol/l in the suspension, ultrasonic 30-120min is to obtaining uniform colloidal solution, add then and press phosphoric acid salt weight 0.5-5 cationic organic modifiers doubly, ultrasonic 30-120min, distilled water is washed till neutrality, obtains organically-modified phosphoric acid salt after the separation; This cationic organic modifiers is selected from Dodecyl trimethyl ammonium chloride, Trimethyllaurylammonium bromide, dodecyl benzyl dimethyl ammonium chloride, dodecyl dimethyl benzyl ammonium bromide, the tetradecyl dimethyl benzyl ammonium chloride, tetradecyl dimethyl benzyl ammonium, palmityl trimethyl ammonium chloride, cetyl trimethylammonium bromide, stearyl dimethyl benzyl ammonium chloride, octadecyl dimethyl benzyl brometo de amonio, octadecyl trimethyl ammonium chloride or octadecyl trimethylammonium bromide;

Described organically-modified double-hydroxide comprises organically-modified magnesium iron double-hydroxide, organically-modified calcium iron double-hydroxide, organically-modified zinc-iron double-hydroxide, organically-modified ferromanganese double-hydroxide, organically-modified ferro-cobalt double-hydroxide, organically-modified ferronickel double-hydroxide, organically-modified copper iron double-hydroxide, organically-modified cobalt aluminium double-hydroxide, organically-modified nickel aluminium double-hydroxide, organically-modified cobalt chromium double-hydroxide, organically-modified nickel chromium triangle double-hydroxide, organically-modified cobalt gallium double-hydroxide or organically-modified nickel gallium double-hydroxide; The preparation method of the double-hydroxide that this is organically-modified is: the mol ratio by divalent-metal ion and trivalent metal ion is that 1-5:1 is mixed with the aqueous solution that the metal ion total concn is 0.1-2mol/l; Under room temperature, stirring, dropwise add the alkaline solution that volumetric molar concentration is 1-4mol/l, adjusting pH is 7.5-12, be warmed up to 70-140 ℃ then, add trivalent ion molar weight 0.5-5 anionic organic modifiers doubly, reaction 6-60h, distilled water is washed till neutrality, obtains organically-modified double-hydroxide after the separation; This anionic organic modifiers is selected from sodium lauryl sulphate, sodium laurylsulfonate, Sodium dodecylbenzene sulfonate, dialkyl benzene sulfonic acids sodium, sodium butylnaphthalenesulfonate, sodium dibutyl naphthalene sulfonate, di-isopropyl sodium naphthalene sulfonate, single two methyl naphthalene sulfonic acid sodium or bay alcohol radical sodium sulfate.

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