CN114477148B - Graphene microchip aggregate, preparation method thereof and preparation method of high-concentration graphene aqueous solution - Google Patents
Graphene microchip aggregate, preparation method thereof and preparation method of high-concentration graphene aqueous solution Download PDFInfo
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- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 411
- 229910021389 graphene Inorganic materials 0.000 title claims abstract description 393
- 239000007864 aqueous solution Substances 0.000 title claims abstract description 72
- 238000002360 preparation method Methods 0.000 title claims abstract description 55
- 238000009830 intercalation Methods 0.000 claims abstract description 51
- 230000002687 intercalation Effects 0.000 claims abstract description 51
- 230000007547 defect Effects 0.000 claims abstract description 44
- 238000000034 method Methods 0.000 claims abstract description 42
- 150000001875 compounds Chemical class 0.000 claims abstract description 19
- 230000004931 aggregating effect Effects 0.000 claims abstract description 5
- 239000010410 layer Substances 0.000 claims description 36
- 238000006243 chemical reaction Methods 0.000 claims description 29
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 21
- 238000000227 grinding Methods 0.000 claims description 17
- 238000005406 washing Methods 0.000 claims description 15
- 239000002253 acid Substances 0.000 claims description 14
- 238000009210 therapy by ultrasound Methods 0.000 claims description 14
- 229910002804 graphite Inorganic materials 0.000 claims description 13
- 239000010439 graphite Substances 0.000 claims description 13
- 239000007800 oxidant agent Substances 0.000 claims description 13
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 10
- 230000001590 oxidative effect Effects 0.000 claims description 10
- 229910052751 metal Inorganic materials 0.000 claims description 9
- 239000002184 metal Substances 0.000 claims description 9
- 238000001035 drying Methods 0.000 claims description 8
- 239000000463 material Substances 0.000 claims description 8
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 7
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 6
- 239000011229 interlayer Substances 0.000 claims description 6
- 238000000926 separation method Methods 0.000 claims description 6
- VZOPRCCTKLAGPN-ZFJVMAEJSA-L potassium;sodium;(2r,3r)-2,3-dihydroxybutanedioate;tetrahydrate Chemical compound O.O.O.O.[Na+].[K+].[O-]C(=O)[C@H](O)[C@@H](O)C([O-])=O VZOPRCCTKLAGPN-ZFJVMAEJSA-L 0.000 claims description 5
- 239000011435 rock Substances 0.000 claims description 5
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 claims description 4
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 4
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 4
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 claims description 4
- 238000005119 centrifugation Methods 0.000 claims description 4
- 239000000919 ceramic Substances 0.000 claims description 4
- IIPYXGDZVMZOAP-UHFFFAOYSA-N lithium nitrate Chemical compound [Li+].[O-][N+]([O-])=O IIPYXGDZVMZOAP-UHFFFAOYSA-N 0.000 claims description 4
- 238000005374 membrane filtration Methods 0.000 claims description 4
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 claims description 4
- VLTRZXGMWDSKGL-UHFFFAOYSA-N perchloric acid Chemical compound OCl(=O)(=O)=O VLTRZXGMWDSKGL-UHFFFAOYSA-N 0.000 claims description 4
- KMUONIBRACKNSN-UHFFFAOYSA-N potassium dichromate Chemical compound [K+].[K+].[O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O KMUONIBRACKNSN-UHFFFAOYSA-N 0.000 claims description 4
- 238000004062 sedimentation Methods 0.000 claims description 4
- -1 small molecule compound Chemical class 0.000 claims description 4
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 claims description 2
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 claims description 2
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims description 2
- 229910021578 Iron(III) chloride Inorganic materials 0.000 claims description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 2
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 claims description 2
- 238000001237 Raman spectrum Methods 0.000 claims description 2
- UIIMBOGNXHQVGW-DEQYMQKBSA-M Sodium bicarbonate-14C Chemical compound [Na+].O[14C]([O-])=O UIIMBOGNXHQVGW-DEQYMQKBSA-M 0.000 claims description 2
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 2
- QZPSXPBJTPJTSZ-UHFFFAOYSA-N aqua regia Chemical compound Cl.O[N+]([O-])=O QZPSXPBJTPJTSZ-UHFFFAOYSA-N 0.000 claims description 2
- 239000001110 calcium chloride Substances 0.000 claims description 2
- 229910001628 calcium chloride Inorganic materials 0.000 claims description 2
- 239000001506 calcium phosphate Substances 0.000 claims description 2
- 229910000389 calcium phosphate Inorganic materials 0.000 claims description 2
- 235000011010 calcium phosphates Nutrition 0.000 claims description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-N carbonic acid Chemical compound OC(O)=O BVKZGUZCCUSVTD-UHFFFAOYSA-N 0.000 claims description 2
- YNQRWVCLAIUHHI-UHFFFAOYSA-L dilithium;oxalate Chemical compound [Li+].[Li+].[O-]C(=O)C([O-])=O YNQRWVCLAIUHHI-UHFFFAOYSA-L 0.000 claims description 2
- 235000019253 formic acid Nutrition 0.000 claims description 2
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 claims description 2
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 claims description 2
- 229910052808 lithium carbonate Inorganic materials 0.000 claims description 2
- XKPJKVVZOOEMPK-UHFFFAOYSA-M lithium;formate Chemical compound [Li+].[O-]C=O XKPJKVVZOOEMPK-UHFFFAOYSA-M 0.000 claims description 2
- 229940097364 magnesium acetate tetrahydrate Drugs 0.000 claims description 2
- XKPKPGCRSHFTKM-UHFFFAOYSA-L magnesium;diacetate;tetrahydrate Chemical compound O.O.O.O.[Mg+2].CC([O-])=O.CC([O-])=O XKPKPGCRSHFTKM-UHFFFAOYSA-L 0.000 claims description 2
- 229910017604 nitric acid Inorganic materials 0.000 claims description 2
- 239000012286 potassium permanganate Substances 0.000 claims description 2
- 239000011734 sodium Substances 0.000 claims description 2
- 229910052708 sodium Inorganic materials 0.000 claims description 2
- 229910000029 sodium carbonate Inorganic materials 0.000 claims description 2
- RSIJVJUOQBWMIM-UHFFFAOYSA-L sodium sulfate decahydrate Chemical compound O.O.O.O.O.O.O.O.O.O.[Na+].[Na+].[O-]S([O-])(=O)=O RSIJVJUOQBWMIM-UHFFFAOYSA-L 0.000 claims description 2
- HIFJUMGIHIZEPX-UHFFFAOYSA-N sulfuric acid;sulfur trioxide Chemical compound O=S(=O)=O.OS(O)(=O)=O HIFJUMGIHIZEPX-UHFFFAOYSA-N 0.000 claims description 2
- QORWJWZARLRLPR-UHFFFAOYSA-H tricalcium bis(phosphate) Chemical compound [Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O QORWJWZARLRLPR-UHFFFAOYSA-H 0.000 claims description 2
- 238000004299 exfoliation Methods 0.000 claims 2
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 claims 1
- 239000000853 adhesive Substances 0.000 claims 1
- 230000001070 adhesive effect Effects 0.000 claims 1
- 125000000524 functional group Chemical group 0.000 abstract description 39
- 238000005516 engineering process Methods 0.000 abstract description 9
- 239000000126 substance Substances 0.000 abstract description 4
- 238000004519 manufacturing process Methods 0.000 description 44
- 238000001000 micrograph Methods 0.000 description 7
- 238000005054 agglomeration Methods 0.000 description 4
- 230000002776 aggregation Effects 0.000 description 4
- 238000000265 homogenisation Methods 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 3
- 239000000543 intermediate Substances 0.000 description 3
- 239000011259 mixed solution Substances 0.000 description 3
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- 239000002994 raw material Substances 0.000 description 3
- 238000001878 scanning electron micrograph Methods 0.000 description 3
- 239000012498 ultrapure water Substances 0.000 description 3
- 230000006978 adaptation Effects 0.000 description 2
- 238000000089 atomic force micrograph Methods 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 150000001721 carbon Chemical group 0.000 description 2
- 238000005229 chemical vapour deposition Methods 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
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- 230000033116 oxidation-reduction process Effects 0.000 description 2
- 150000003384 small molecules Chemical class 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 238000002604 ultrasonography Methods 0.000 description 2
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 230000003044 adaptive effect Effects 0.000 description 1
- 238000004630 atomic force microscopy Methods 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/15—Nano-sized carbon materials
- C01B32/182—Graphene
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/15—Nano-sized carbon materials
- C01B32/182—Graphene
- C01B32/184—Preparation
- C01B32/19—Preparation by exfoliation
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2204/00—Structure or properties of graphene
- C01B2204/04—Specific amount of layers or specific thickness
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2204/00—Structure or properties of graphene
- C01B2204/20—Graphene characterized by its properties
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2204/00—Structure or properties of graphene
- C01B2204/20—Graphene characterized by its properties
- C01B2204/28—Solid content in solvents
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2204/00—Structure or properties of graphene
- C01B2204/20—Graphene characterized by its properties
- C01B2204/32—Size or surface area
Abstract
The invention provides a graphene microchip aggregate, which is formed by aggregating graphene microchip; the graphene microchip aggregate microscopically has a layered structure. According to the invention, the graphene microchip aggregate with a specific structure is obtained, the graphene has a stacked structure of micron-sized graphene microchip, and the graphene microchip aggregate can be used for preparing high-quality graphene. The graphene prepared by the method has a graphene structure with a lamellar layer smaller than 10 layers, is low in surface functional groups and defect degree, high in graphene quality and is a thin-layer low-defect graphene. According to the preparation method provided by the invention, the nano graphene is prepared in the aqueous solution by the mechanical stripping, the secondary chemical thermal expansion and the small molecular compound intercalation technology, so that the preparation of the high-concentration graphene aqueous solution under the environment-friendly and pollution-free conditions is realized, the method is simple, the cost is low, and the preparation method is more suitable for industrial popularization and application.
Description
Technical Field
The invention belongs to the technical field of graphene, relates to a graphene microchip aggregate and a preparation method thereof, and a preparation method of a graphene aqueous solution, and particularly relates to a graphene microchip aggregate and a preparation method thereof, and a preparation method of a high-concentration graphene aqueous solution.
Background
Graphene (Graphene) is a new material of a single-layer sheet structure composed of carbon atoms. It is a compound comprising a carbon atom and sp 2 Planar film with hexagonal lattice and sp composed of hybridized orbitals 2 The hybridized carbon six-membered ring-shaped two-dimensional crystal structure is a basic unit for constructing carbon materials with other dimensions. The basic structural unit is the most stable benzene six-membered ring in the organic material, the theoretical thickness is only 0.335nm, and the two-dimensional material with the thickness of only one carbon atom is the currently found oneThe thinnest two-dimensional material among the known materials. Since Geim et al prepared graphene by a micromechanical stripping method for the first time in 2004, graphene has attracted much attention because of its excellent properties such as high conductivity, high specific surface area, high strength, high electron mobility, and the like, and further has promoted rapid development of graphene preparation technology. Due to the excellent physicochemical properties, the material is widely applied to energy storage materials, environmental engineering and sensitive sensing, is called "black gold" or "king of new materials", has wide potential application prospect, and is now a focus of attention and research hotspot worldwide.
However, although graphene has excellent performance, in practical application, graphene has a plurality of problems and constraint factors, and regarding the preparation method, most of graphene prepared by the existing physical stripping mode is prepared under a water system and an oil system, and a graphene drying step exists, so that the graphene is seriously overlapped, the graphene characteristics are not obvious, and nano-scale graphene with smaller thickness cannot be obtained; and graphene prepared by oxidation reduction has more surface functional groups and high defects. The application range of the graphene is limited. The laboratory-level CVD method is too complicated in preparation process, harsh in conditions, low in yield, high in cost and difficult to control the production efficiency, and the nano graphene sheet diameter is difficult to separate from the substrate, so that the method is not suitable for mass production and difficult to realize large-scale industrial production and popularization and application. Particularly in industrial practical application, in order to better improve the dispersion performance of the nano graphene, the nano graphene is often in the form of a graphene aqueous solution product, but the existing graphene aqueous solution, particularly a high-concentration graphene aqueous solution, still has the problems of unstable performance, easy agglomeration, long-time layering and the like, so that the popularization and application of the graphene product are greatly limited.
Therefore, how to find an adaptive graphene preparation method solves the technical problems existing in the existing preparation and hard rock, has a better industrialization prospect, and becomes one of the problems to be solved urgently for many research and development enterprises and first-line researchers in the industry.
Disclosure of Invention
In view of the above, the technical problems to be solved by the invention are to provide a graphene microchip aggregate, a preparation method thereof and a preparation method of a graphene aqueous solution, in particular to a preparation method of a high-concentration graphene aqueous solution.
The invention provides a graphene microchip aggregate, which is formed by aggregating graphene microchip;
the graphene microchip aggregate microscopically has a layered structure.
Preferably, the graphene microchip aggregate has a layered structure of rock stacks;
the graphene sheet aggregate has a layered stack structure along a single direction and a direction perpendicular to the single direction;
Interlayer gaps are formed between layers of the graphene microchip aggregate;
the distance between the interlayer gaps is 10-20 mu m;
the graphene microchip aggregate is a micron-sized material.
Preferably, the thickness of the graphene aggregate is 200-500 μm;
the radial dimension of the graphene aggregate is 0.1-2 mm;
the graphene microchip has a wrinkled shape;
the graphene microplates are stacked in layers and/or staggered;
the thickness of the graphene microchip is 5-8 nm;
the diameter of the graphene microchip is 1-10 mu m.
The invention provides a preparation method of graphene microchip aggregates, which comprises the following steps:
1) Ultrasonic grinding and homogenizing are carried out on the expanded graphite to obtain an intermediate;
2) And (3) carrying out intercalation reaction on the intermediate, the acid and the oxidant obtained in the steps, and then carrying out thermal expansion treatment to obtain the graphene microchip aggregate.
Preferably, the ultrasonic treatment time is 10-120 min;
the frequency of the ultrasonic wave is 1000-3000 Hz;
the grinding mode comprises sanding;
the grinding time is 20-80 min;
the grinding rotating speed is 1000-3000 r/min;
the homogenizing pressure is 30-120 MPa;
The homogenizing time is 5-20 min;
the acid includes one or more of sulfuric acid, phosphoric acid, hydrochloric acid, nitric acid, perchloric acid, aqua regia, carbonic acid, formic acid, acetic acid and hydrofluoric acid.
Preferably, the oxidant comprises one or more of potassium permanganate, hydrogen peroxide, potassium dichromate, fuming sulfuric acid, ozone, chlorine and sodium ferrate;
the mass ratio of the intermediate to the acid is 1: (10-100);
the mass ratio of the intermediate to the oxidant is 1: (1-5);
the time of the intercalation reaction is 1-3 h;
the temperature of the intercalation reaction is 20-50 ℃;
the intercalation reaction is followed by a drying step;
the temperature of the thermal expansion treatment is 900-1100 ℃;
the time of the thermal expansion treatment is 10-60 min.
The invention provides a preparation method of a graphene aqueous solution, which comprises the following steps:
a) And (3) carrying out re-stripping and small molecular compound intercalation reaction on the graphene microchip aggregate, and then carrying out stripping-assisting and water washing to obtain a graphene aqueous solution.
Preferably, the re-peeling mode comprises water bath ultrasonic treatment and/or ultrasonic bar treatment;
the time for re-stripping is 60-120 min;
the frequency of the re-stripping is 1000-3000 Hz;
The small molecule compound comprises a metal small molecule compound;
the temperature of the intercalation reaction is 30-90 ℃;
the time of the intercalation reaction is 60-180 min;
the graphene is low-defect graphene.
Preferably, the peeling-assisting mode comprises ultrasonic peeling-assisting;
the water washing mode comprises ultrasonic water washing;
the mass ratio of the graphene microchip aggregate to the micromolecular compound is (1-2): 1, a step of;
the metal small molecular compound comprises one or more of potassium sodium tartrate tetrahydrate, sodium sulfate decahydrate, magnesium acetate tetrahydrate, sodium carbonate, sodium bicarbonate, ferric chloride, lithium nitrate, lithium oxalate, lithium formate, lithium carbonate, calcium chloride and calcium phosphate;
the intercalation reaction comprises the following specific steps:
preserving heat for 10-30 min at 30-40 ℃ in the first stage, preserving heat for 30-60 min at 50-60 ℃ in the second stage, and preserving heat for 20-30 min at 80-90 ℃ in the third stage;
the ultrasonic stripping-assisting mode comprises water bath ultrasonic stripping-assisting and/or ultrasonic rod stripping-assisting;
the graphene is nanoscale graphene.
Preferably, the ultrasonic assisted stripping time is 60-120 min;
the frequency of the ultrasonic stripping aid is 1000-3000 Hz;
The washing process further comprises a separation step;
the separation mode comprises one or more of a centrifugation method, a sedimentation method and a ceramic membrane filtration method;
the concentration of the graphene aqueous solution is 0.1% -10%;
the number of the graphene sheets is less than or equal to 10;
the sheet diameter of the graphene is 1-5 mu m;
the defect degree of the graphene is that the Id/Ig value of the Raman spectrum is smaller than 0.1.
The invention provides a graphene microchip aggregate, which is formed by aggregating graphene microchip; the graphene microchip aggregate microscopically has a layered structure. Compared with the prior art, the graphene prepared by the physical stripping method has thicker lamellar, the graphene has insignificant characteristics, and the graphene with smaller thickness can not be obtained; and graphene prepared by oxidation reduction has more surface functional groups and high defects. The application range of the graphene is limited; the CVD method has the problems that the preparation process is too complicated, the conditions are harsh, the production efficiency is affected, the diameter of the nano graphene sheet is difficult to control, the graphene and the substrate are difficult to separate, and large-scale industrialized production, popularization and application and the like are difficult to realize. Particularly, the high-concentration graphene aqueous solution still has the problems of unstable performance, easy agglomeration, long-time layering and the like.
According to the invention, the graphene microchip aggregate with a specific structure is obtained, the graphene has a stacked structure of micron-sized graphene microchip, and the graphene microchip aggregate can be used for preparing high-quality graphene. The graphene prepared by the method has a graphene structure with a lamellar layer smaller than 10 layers, is low in surface functional groups and defect degree, high in graphene quality and is a thin-layer low-defect graphene. The preparation method provided by the invention creatively prepares the nano graphene in the aqueous solution by the technology of mechanical stripping, secondary chemical thermal expansion and small molecular compound intercalation, realizes the promotion of the expanded graphite after the pretreatment of the expanded graphite and the high-temperature expansion, carries out the stripping of the graphene by the assistance of ultrasound through the secondary intercalation of metal small molecules and the ultrasonic washing, realizes the preparation of the high-concentration graphene aqueous solution under the environment-friendly and pollution-free conditions, has the advantages of simple method and low cost, and is more suitable for industrialized popularization and application.
The graphene aqueous solution prepared by the method has higher concentration, can prepare graphene concentration ranges of 1-10% according to the needs, has better dispersibility and stability, has simple preparation process, and can realize industrialized preparation of graphene. The high-concentration nano graphene aqueous solution obtained by the method can be used for preparing graphene with a sheet layer of less than 10 layers under a simple process, and the secondary intercalation stripping technology is adopted, so that the yield of the nano graphene is higher, the concentration is higher than that of the nano graphene obtained by the common technology, and the highest yield concentration can reach 10%. The high-concentration nano graphene creates a proper condition for the next graphene application.
Experimental results show that the graphene prepared by the method has smaller defect degree (Id/Ig is less than 0.1), the thickness of the sheet layer is thinner (10 layers), and the graphene has better dispersibility and no obvious agglomeration phenomenon under high concentration (10% concentration).
Drawings
Fig. 1 is an SEM scanning electron microscope image of graphene microchip aggregates prepared in example 1 of the present invention;
FIG. 2 is a high-magnification SEM image of graphene microchip aggregates prepared in example 1 of the present invention;
FIG. 3 is an AFM atomic force microscope image of graphene prepared according to the present invention;
FIG. 4 is a high-magnification SEM image of graphene microchip aggregates prepared in example 2 of the present invention;
FIG. 5 is a high resolution field emission transmission electron microscope image of graphene prepared in accordance with the present invention;
FIG. 6 is a high-magnification SEM image of graphene microchip aggregates prepared in example 3 of the present invention;
fig. 7 is an infrared spectrogram of graphene prepared according to the present invention.
Detailed Description
For a further understanding of the present invention, preferred embodiments of the invention are described below in conjunction with the examples, but it should be understood that these descriptions are merely intended to illustrate further features and advantages of the invention and are not limiting of the invention claims.
All the raw materials of the present invention are not particularly limited in their sources, and may be purchased on the market or prepared according to conventional methods well known to those skilled in the art.
All raw materials of the invention are not particularly limited in purity, and the invention preferably adopts analytically pure or graphene to prepare conventional purity requirements.
All raw materials of the invention, the brands and abbreviations of which belong to the conventional brands and abbreviations in the field of the related application are clear and definite, and the person skilled in the art can purchase from the market or prepare by the conventional method according to the brands, abbreviations and the corresponding application.
The invention provides a graphene microchip aggregate, which is formed by aggregating graphene microchip;
the graphene microchip aggregate microscopically has a layered structure.
The morphology of the graphene microchip aggregate is not particularly limited in principle, and can be selected and adjusted according to actual production conditions, product requirements and quality requirements by a person skilled in the art, so that the morphology of graphene prepared subsequently is further improved, the surface functional groups and the defect degree of graphene are reduced, the quality of graphene is improved, the dispersibility and the stability of a graphene aqueous solution are finally improved, and the graphene microchip aggregate preferably has the morphology of a layered structure formed by stacking rocks in a microcosmic manner.
The structure of the graphene sheet aggregate is not particularly limited in principle, and can be selected and adjusted according to actual production conditions, product requirements and quality requirements by a person skilled in the art.
The invention is in principle not particularly limited to the specific morphology and parameters of the layered stacked structure, and a person skilled in the art can select and adjust the specific morphology and parameters according to actual production conditions, product requirements and quality requirements. The distance between the interlayer voids in the present invention is preferably 10 to 20. Mu.m, more preferably 12 to 18. Mu.m, still more preferably 14 to 16. Mu.m.
The specific category of the graphene microchip aggregate is not particularly limited in principle, and can be selected and adjusted according to actual production conditions, product requirements and quality requirements by a person skilled in the art.
The thickness of the graphene aggregate is not particularly limited in principle, and can be selected and adjusted according to actual production conditions, product requirements and quality requirements by a person skilled in the art, so that the morphology of the graphene prepared later is further improved, the surface functional groups and the defect degree of the graphene are reduced, the quality of the graphene is improved, and finally the dispersibility and the stability of the graphene aqueous solution are improved, wherein the thickness of the graphene aggregate is preferably 200-500 mu m, more preferably 250-450 mu m, and even more preferably 300-400 mu m.
The radial dimension of the graphene aggregate is not particularly limited in principle, and can be selected and adjusted according to actual production conditions, product requirements and quality requirements by a person skilled in the art, so that the morphology of the graphene prepared later is further improved, the surface functional groups and the defect degree of the graphene are reduced, the quality of the graphene is improved, and finally the dispersibility and the stability of the graphene aqueous solution are improved, wherein the radial dimension of the graphene aggregate is preferably 0.1-2 mm, more preferably 0.3-1.8 mm, more preferably 0.5-1.5 mm, and even more preferably 0.8-1.2 mm.
The invention provides a preparation method of graphene microchip aggregates, which comprises the following steps:
1) Ultrasonic grinding and homogenizing are carried out on the expanded graphite to obtain an intermediate;
2) And (3) carrying out intercalation reaction on the intermediate, the acid and the oxidant obtained in the steps, and then carrying out thermal expansion treatment to obtain the graphene microchip aggregate.
The parameters and the selection of the products in the preparation method and the corresponding preferred principles of the products in the graphene microchip aggregate can be corresponding to the parameters and the selection of the products in the graphene microchip aggregate and the corresponding preferred principles, and are not described in detail herein.
The invention firstly obtains an intermediate after ultrasonic treatment, grinding and homogenization of the expanded graphite.
The ultrasonic time is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, product requirements and quality requirements, so that the morphology of the graphene prepared later is further improved, the surface functional groups and the defect degree of the graphene are reduced, the quality of the graphene is improved, and finally the dispersibility and the stability of the graphene aqueous solution are improved, wherein the ultrasonic time is preferably 10-120 min, more preferably 30-100 min, and even more preferably 50-80 min.
The ultrasonic frequency is not particularly limited in principle, and can be selected and adjusted according to actual production conditions, product requirements and quality requirements by a person skilled in the art, so that the morphology of the graphene prepared subsequently is further improved, the surface functional groups and the defect degree of the graphene are reduced, the quality of the graphene is improved, and finally the dispersibility and the stability of the graphene aqueous solution are improved, wherein the ultrasonic frequency is preferably 1000-3000 Hz, more preferably 1400-2600 Hz, and even more preferably 1800-2200 Hz.
The grinding mode is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, product requirements and quality requirements, and the grinding mode preferably comprises sanding in order to further improve the morphology of the subsequently prepared graphene, reduce the surface functional groups and defect degree of the graphene, improve the quality of the graphene and finally improve the dispersibility and stability of the graphene aqueous solution.
The grinding time is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, product requirements and quality requirements, so that the morphology of the graphene prepared later is further improved, the surface functional groups and the defect degree of the graphene are reduced, the quality of the graphene is improved, and finally the dispersibility and the stability of the graphene aqueous solution are improved, wherein the grinding time is preferably 20-80 min, more preferably 30-70 min, and even more preferably 40-60 min.
The grinding rotating speed is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, product requirements and quality requirements, so that the morphology of the graphene prepared later is further improved, the surface functional groups and the defect degree of the graphene are reduced, the quality of the graphene is improved, and finally the dispersibility and the stability of the graphene aqueous solution are improved, wherein the grinding rotating speed is preferably 1000-3000 r/min, more preferably 1400-2600 r/min, and even more preferably 1800-2200 r/min.
The method is in principle not particularly limited to the homogeneous pressure, and a person skilled in the art can select and adjust the pressure according to actual production conditions, product requirements and quality requirements, and the method is used for further improving the morphology of the subsequently prepared graphene, reducing the surface functional groups and the defect degree of the graphene, improving the quality of the graphene and finally improving the dispersibility and the stability of the graphene aqueous solution, wherein the homogeneous pressure is preferably 30-120 MPa, more preferably 50-100 MPa, and even more preferably 70-80 MPa.
The homogenization time is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, product requirements and quality requirements, so that the morphology of the graphene prepared later is further improved, the surface functional groups and the defect degree of the graphene are reduced, the quality of the graphene is improved, and finally the dispersibility and the stability of the graphene aqueous solution are improved, wherein the homogenization time is preferably 5-20 min, more preferably 8-17 min, and even more preferably 11-14 min.
Finally, the intermediate, the acid and the oxidant obtained in the steps are subjected to intercalation reaction and then subjected to thermal expansion treatment to obtain the graphene microchip aggregate.
The specific choice of the acid is not particularly limited in principle, and a person skilled in the art can choose and adjust the acid according to actual production conditions, product requirements and quality requirements, so as to further improve the morphology of the graphene prepared later, reduce the surface functional groups and defects of the graphene, improve the quality of the graphene, and finally improve the dispersibility and stability of the aqueous graphene solution.
The specific choice of the oxidizing agent is not particularly limited in principle, and a person skilled in the art can select and adjust the oxidizing agent according to actual production conditions, product requirements and quality requirements.
The mass ratio of the intermediate to the acid is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, product requirements and quality requirements, and the mass ratio of the intermediate to the acid is preferably 1: (10 to 100), more preferably 1: (30 to 80), more preferably 1: (50-60).
The mass ratio of the intermediate to the oxidant is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, product requirements and quality requirements, and the mass ratio of the intermediate to the oxidant is preferably 1: (1 to 5), more preferably 1: (1.5 to 4.5), more preferably 1: (2 to 4), more preferably 1: (2.5-3.5).
The time of the intercalation reaction is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, product requirements and quality requirements, and the time of the intercalation reaction is preferably 1-3 hours, more preferably 1.4-2.6 hours, and even more preferably 1.8-2.2 hours, in order to further improve the morphology of the subsequently prepared graphene, reduce the surface functional groups and defect degree of the graphene, improve the quality of the graphene and finally improve the dispersibility and stability of the graphene aqueous solution.
The temperature of the intercalation reaction is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, product requirements and quality requirements, and the temperature of the intercalation reaction is preferably 20-50 ℃, more preferably 25-45 ℃, and even more preferably 30-40 ℃ in order to further improve the morphology of the subsequently prepared graphene, reduce the surface functional groups and defect degree of the graphene, improve the quality of the graphene and finally improve the dispersibility and stability of the graphene aqueous solution.
The invention is an integral and refined preparation process, which further improves the morphology of the graphene prepared later, reduces the surface functional groups and the defect degree of the graphene, improves the quality of the graphene, and finally improves the dispersibility and the stability of the graphene aqueous solution, and the intercalation reaction is preferably followed by a drying step.
The temperature of the thermal expansion treatment is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, product requirements and quality requirements, and the temperature of the thermal expansion treatment is preferably 900-1100 ℃, more preferably 940-1060 ℃, and even more preferably 980-1020 ℃ in order to further improve the morphology of the graphene prepared later, reduce the surface functional groups and defect degree of the graphene, improve the quality of the graphene and finally improve the dispersibility and stability of the graphene aqueous solution.
The time of the thermal expansion treatment is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, product requirements and quality requirements, and the time of the thermal expansion treatment is preferably 10-60 min, more preferably 20-50 min, and even more preferably 30-40 min, in order to further improve the morphology of the graphene prepared later, reduce the surface functional groups and defect degree of the graphene, improve the quality of the graphene and finally improve the dispersibility and stability of the graphene aqueous solution.
The invention also provides a preparation method of the graphene aqueous solution, which comprises the following steps:
a) And (3) carrying out re-stripping and small molecular compound intercalation reaction on the graphene microchip aggregate, and then carrying out stripping-assisting and water washing to obtain a graphene aqueous solution.
The parameters, the selection and the preparation method of the graphene microchip aggregate and the corresponding preferred principles in the preparation method of the graphene aqueous solution can correspond to the parameters, the selection and the preparation method of the graphene microchip aggregate and the preparation method thereof and the corresponding preferred principles, and are not described in detail herein.
The method for re-stripping is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, product requirements and quality requirements, and in order to further improve the morphology of the prepared graphene, reduce the surface functional groups and the defect degree of the graphene, improve the quality of the graphene and finally improve the dispersibility and the stability of the aqueous solution of the graphene, the re-stripping method preferably comprises water bath ultrasonic treatment and/or ultrasonic bar treatment, and more preferably water bath ultrasonic treatment or ultrasonic bar treatment.
The time for re-stripping is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, product requirements and quality requirements, so that the morphology of the prepared graphene is further improved, the surface functional groups and the defect degree of the graphene are reduced, the quality of the graphene is improved, and finally the dispersibility and the stability of the graphene aqueous solution are improved, wherein the time for re-stripping is preferably 60-120 min, more preferably 70-110 min, and even more preferably 80-100 min.
The frequency of the re-stripping is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, product requirements and quality requirements, so that the morphology of the prepared graphene is further improved, the surface functional groups and the defect degree of the graphene are reduced, the quality of the graphene is improved, and finally the dispersibility and the stability of the aqueous solution of the graphene are improved, wherein the frequency of the re-stripping is preferably 1000-3000 Hz, more preferably 1400-2600 Hz, and even more preferably 1800-2200 Hz.
The invention is not particularly limited in principle for the specific selection of the small molecular compound, and a person skilled in the art can select and adjust the small molecular compound according to actual production conditions, product requirements and quality requirements.
The temperature of the intercalation reaction is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, product requirements and quality requirements, and the temperature of the intercalation reaction is preferably 30-90 ℃, more preferably 40-80 ℃, and even more preferably 50-70 ℃ in order to further improve the morphology of the prepared graphene, reduce the surface functional groups and defect degree of the graphene, improve the quality of the graphene and finally improve the dispersibility and stability of the graphene aqueous solution.
The time of the intercalation reaction is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, product requirements and quality requirements, so that the morphology of the prepared graphene is further improved, the surface functional groups and the defect degree of the graphene are reduced, the quality of the graphene is improved, and finally the dispersibility and the stability of the graphene aqueous solution are improved, wherein the time of the intercalation reaction is preferably 60-180 min, more preferably 80-160 min, and even more preferably 100-140 min.
The specific selection of the graphene is not particularly limited in principle, and can be selected and adjusted according to actual production conditions, product requirements and quality requirements by a person skilled in the art.
The stripping-assisting mode is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, product requirements and quality requirements, and the stripping-assisting mode preferably comprises ultrasonic stripping-assisting in order to further improve the morphology of the prepared graphene, reduce the surface functional groups and defect degree of the graphene, improve the quality of the graphene and finally improve the dispersibility and stability of the graphene aqueous solution.
The method is not particularly limited in principle, and a person skilled in the art can select and adjust the method according to actual production conditions, product requirements and quality requirements.
The mass ratio of the graphene microchip aggregate to the small molecular compound is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, product requirements and quality requirements, and the mass ratio of the graphene microchip aggregate to the small molecular compound is preferably (1-2): 1, more preferably (1.2 to 1.8): 1, more preferably (1.4 to 1.6): 1.
the specific choice of the metal small molecular compound is not particularly limited in principle, and a person skilled in the art can choose and adjust the metal small molecular compound according to actual production conditions, product requirements and quality requirements, so that the morphology of the prepared graphene is further improved, the surface functional groups and defects of the graphene are reduced, the quality of the graphene is improved, and finally the dispersibility and stability of a graphene aqueous solution are improved.
The invention is an integral and refined preparation process, which further improves the appearance of the prepared graphene, reduces the surface functional groups and defect degree of the graphene, improves the quality of the graphene, and finally improves the dispersibility and stability of the graphene aqueous solution, and the specific steps of the intercalation reaction are preferably as follows:
the temperature is kept for 10 to 30 minutes at the temperature of 30 to 40 ℃ in the first stage, the temperature is kept for 30 to 60 minutes at the temperature of 50 to 60 ℃ in the second stage, and the temperature is kept for 20 to 30 minutes at the temperature of 80 to 90 ℃ in the third stage.
The method is not particularly limited in principle, and a person skilled in the art can select and adjust the method according to actual production conditions, product requirements and quality requirements, so as to further improve the morphology of the prepared graphene, reduce the surface functional groups and defect degree of the graphene, improve the quality of the graphene, and finally improve the dispersibility and stability of the graphene aqueous solution.
The specific selection of the graphene is not particularly limited in principle, and can be selected and adjusted according to actual production conditions, product requirements and quality requirements by a person skilled in the art.
The ultrasonic assisted stripping time is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, product requirements and quality requirements, so that the morphology of the prepared graphene is further improved, the surface functional groups and the defect degree of the graphene are reduced, the quality of the graphene is improved, and finally the dispersibility and the stability of the graphene aqueous solution are improved, wherein the ultrasonic assisted stripping time is preferably 60-120 min, more preferably 70-110 min, and even more preferably 80-100 min.
The frequency of the ultrasonic assisted stripping is not particularly limited in principle, and can be selected and adjusted according to actual production conditions, product requirements and quality requirements by a person skilled in the art, so that the morphology of the prepared graphene is further improved, the surface functional groups and the defect degree of the graphene are reduced, the quality of the graphene is improved, and finally the dispersibility and the stability of the graphene aqueous solution are improved, wherein the frequency of the ultrasonic assisted stripping is preferably 1000-3000 Hz, more preferably 1400-2600 Hz, and even more preferably 1800-2200 Hz.
The invention is an integral and refined preparation process, which further improves the appearance of the prepared graphene, reduces the surface functional groups and defects of the graphene, improves the quality of the graphene, and finally improves the dispersibility and stability of the graphene aqueous solution, and the washing process preferably further comprises a separation step, more particularly, the separation mode preferably comprises one or more of a centrifugation method, a sedimentation method and a ceramic membrane filtration method, and more preferably comprises a centrifugation method, a sedimentation method or a ceramic membrane filtration method.
The concentration of the graphene aqueous solution is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, product requirements and quality requirements, so that the morphology of the prepared graphene is further improved, the surface functional groups and the defect degree of the graphene are reduced, the quality of the graphene is improved, and finally the dispersibility and the stability of the graphene aqueous solution are improved, wherein the concentration of the graphene aqueous solution is preferably 0.1% -10%, more preferably 1% -9.5%, more preferably 5% -9%, more preferably 6% -9%, and particularly can be 5% -10%.
The number of the lamellar layers of the graphene is not particularly limited in principle, and can be selected and adjusted according to actual production conditions, product requirements and quality requirements by a person skilled in the art, so that the morphology of the prepared graphene is further improved, the surface functional groups and the defect degree of the graphene are reduced, the quality of the graphene is improved, and finally the dispersibility and the stability of the graphene aqueous solution are improved, wherein the lamellar number of the graphene is preferably 10 layers or less, more preferably 8 layers or less, and even more preferably 6 layers or less.
The invention is not particularly limited in principle, and a person skilled in the art can select and adjust the sheet diameter of the graphene according to actual production conditions, product requirements and quality requirements, so that the morphology of the prepared graphene is further improved, the surface functional groups and the defect degree of the graphene are reduced, the quality of the graphene is improved, and finally the dispersibility and the stability of the graphene aqueous solution are improved, wherein the sheet diameter of the graphene is preferably 1-5 mu m, more preferably 1.5-4.5 mu m, more preferably 2-4 mu m, and more preferably 2.5-3.5 mu m.
The defect degree of the graphene is not particularly limited in principle, and can be selected and adjusted according to actual production conditions, product requirements and quality requirements by a person skilled in the art.
According to the preparation method, a graphene structure with a sheet layer smaller than 10 layers can be prepared by a simple process, and the preparation of the thin-layer graphene with lower surface functional groups and defect degree and the high-concentration graphene aqueous solution can be realized by the mechanical stripping, the secondary chemical thermal expansion and the micromolecular compound intercalation technology.
The invention discloses an integrated preparation process for preparing graphene, which is characterized in that the appearance of the prepared graphene is further improved, the surface functional groups and the defect degree of the graphene are reduced, the quality of the graphene is improved, and the dispersibility and the stability of a graphene aqueous solution are finally improved, and the preparation method of the graphene aqueous solution specifically comprises the following steps:
(1) Sequentially carrying out ultrasonic treatment, grinding and homogenization on the expanded graphite, mixing the expanded graphite with acid and an oxidant, carrying out primary intercalation treatment, drying after intercalation, and carrying out thermal expansion treatment to obtain graphene microchip aggregates;
(2) Carrying out primary stripping on the graphene microchip aggregate after heat treatment by ultrasonic, and then adding a metal micromolecular compound for secondary intercalation treatment;
(3) And carrying out ultrasonic treatment on the graphene subjected to the secondary intercalation treatment, and then carrying out ultrasonic water washing, and collecting to obtain a high-concentration nano graphene aqueous solution.
The invention provides a graphene microchip aggregate, a preparation method thereof and a preparation method of a high-concentration graphene aqueous solution. According to the preparation method, the graphene microchip aggregate with the specific structure is prepared, the graphene has a stacking structure of micron-sized graphene microchip, and then the graphene microchip aggregate is prepared to obtain the high-quality graphene aqueous solution. The graphene prepared by the method has a graphene structure with a lamellar layer smaller than 10 layers, is low in surface functional groups and defect degree, high in graphene quality and is a thin-layer low-defect graphene. According to the preparation method provided by the invention, the preparation of the nano graphene is carried out in the aqueous solution by the technology of mechanical stripping, secondary chemical thermal expansion and small molecular compound intercalation, after the pretreatment of the expanded graphite, the promotion of the expanded graphite is realized by acid intercalation and high-temperature expansion, the graphene stripping is carried out by the assistance of ultrasound through the secondary intercalation of metal small molecules, and the preparation of the high-concentration graphene aqueous solution under the environment-friendly and pollution-free conditions is realized by ultrasonic washing.
The graphene aqueous solution prepared by the method has higher concentration, can prepare graphene concentration ranges of 1-10% according to the needs, has better dispersibility and stability, has simple preparation process, and can realize industrialized preparation of graphene. The high-concentration nano graphene aqueous solution obtained by the method can be used for preparing graphene with a sheet layer of less than 10 layers under a simple process, and the secondary intercalation stripping technology is adopted, so that the yield of the nano graphene is higher, the concentration is higher than that of the nano graphene obtained by the common technology, and the highest yield concentration can reach 10%. The high-concentration nano graphene creates a proper condition for the next graphene application.
Experimental results show that the graphene prepared by the method has smaller defect degree (Id/Ig is less than 0.1), the thickness of the sheet layer is thinner (10 layers), and the graphene has better dispersibility and no obvious agglomeration phenomenon under high concentration (10% concentration).
For further explanation of the present invention, a graphene microchip aggregate, a preparation method thereof, and a preparation method of a graphene aqueous solution are described in detail below with reference to examples, but it should be understood that these examples are implemented on the premise of the technical scheme of the present invention, and detailed implementation and specific operation procedures are given, which are only for further explaining the features and advantages of the present invention, and not limiting the claims of the present invention, and the scope of protection of the present invention is not limited to the examples described below.
Example 1
5g of expanded graphite is subjected to ultrasonic treatment for 80min at the frequency of 2000Hz, then is subjected to sanding for 60min at the rotating speed of 1800r/min, and is homogenized for 5min under the condition of 80MPa to obtain an intermediate.
Then the intermediate and concentrated sulfuric acid and hydrogen peroxide are mixed according to the following ratio of 1:40:1, carrying out intercalation stripping on the mass ratio, drying the intercalated sample, and carrying out thermal expansion treatment at 1000 ℃ for 10min to obtain the thin-layer graphene microchip aggregate.
The thin-layer graphene microchip aggregate prepared in the embodiment 1 of the present invention is characterized.
Referring to fig. 1, fig. 1 is an SEM scanning electron microscope image of a graphene microchip aggregate prepared in example 1 of the present invention.
As can be seen from fig. 1, the micron-sized graphene microchip aggregate prepared by the present invention has a layered structure similar to that of a rock stack, and has an interlayer gap of 10 to 20 μm between layers in a single direction and a direction perpendicular to the single direction, and has a thickness of 200 to 500 μm as a whole and a radial dimension of approximately 0.1 to 2mm.
Referring to fig. 2, fig. 2 is a high-magnification SEM scanning electron microscope image of the graphene microchip aggregate prepared in example 1 of the present invention.
As can be seen from fig. 2, the graphene microplates on the graphene microplate aggregate have a wrinkled morphology, and the plurality of graphene microplates are stacked in a layered manner and are stacked in a staggered manner, the thickness of the graphene microplates is about 5 to 8nm, and the plate diameter of the graphene microplates is about 1 to 10 μm.
And (3) putting the graphene microchip aggregate into high-purity water, and carrying out ultrasonic treatment for 60min under the condition of 3000Hz to strip again to obtain the graphene microchip.
Then according to the thin-layer graphene microplates: and (3) carrying out a secondary intercalation experiment on the potassium sodium tartrate tetrahydrate=1:1 ratio, wherein the temperature of the secondary intercalation water bath is divided into three stages, namely, 30 ℃ in one stage, 10min in the other stage, 50 ℃ in the other stage, 30min in the other stage, 80 ℃ in the other stage, 20min in the other stage, carrying out secondary ultrasonic assisted stripping when the temperature of the solution is reduced to room temperature, and the stripping time is 80min, and washing the obtained stripped graphene mixed solution with water for 2-5 times to obtain a graphene aqueous solution.
The graphene prepared in example 1 of the present invention was characterized.
Referring to fig. 3, fig. 3 is an AFM atomic force microscope image of graphene prepared according to the present invention.
As can be seen from fig. 3, random results from atomic force microscopy of graphene were characterized.
The result shows that the graphene has a few-layer structure, and the average lamellar layer is less than 10 layers.
Example 2
5g of expanded graphite is subjected to ultrasonic treatment for 80min at the frequency of 2000Hz, then is subjected to sanding for 60min at the rotating speed of 2000r/min, and is homogenized for 5min under the condition of 100MPa to obtain an intermediate.
Then the intermediate and concentrated sulfuric acid and hydrogen peroxide are mixed according to the following ratio of 1:40:1, carrying out intercalation stripping on the mass ratio, drying the intercalated sample, and carrying out thermal expansion treatment at 1000 ℃ for 10min to obtain the thin-layer graphene microchip aggregate.
Referring to fig. 4, fig. 4 is a high-magnification SEM scanning electron microscope image of the graphene microchip aggregate prepared in example 2 of the present invention.
As can be seen from fig. 4, the graphene microplates on the graphene microplate aggregate have a wrinkled morphology, and the plurality of graphene microplates are stacked in a layered manner and are stacked in a staggered manner, the thickness of the graphene microplates is about 5 to 8nm, and the plate diameter of the graphene microplates is about 1 to 10 μm.
And (3) putting the graphene microchip aggregate into high-purity water, and carrying out ultrasonic treatment for 80min under the condition of 3000Hz to strip again to obtain the graphene microchip.
Then according to the thin-layer graphene microplates: and (3) carrying out a secondary intercalation experiment on the potassium sodium tartrate tetrahydrate=1:1 ratio, wherein the temperature of the secondary intercalation water bath is divided into three stages, namely, 30 ℃ at one stage, 20 minutes at two stages, 50 ℃ at two stages, 40 minutes at three stages, 80 ℃ at three stages, 30 minutes at three stages, carrying out secondary ultrasonic assisted stripping when the temperature of the solution is reduced to room temperature, and the stripping time is 80 minutes, and washing the obtained stripped graphene mixed solution with water for 2-5 times to obtain a graphene aqueous solution.
The graphene prepared in example 2 of the present invention was characterized.
Referring to fig. 5, fig. 5 is a high-resolution field emission transmission electron microscope image of graphene prepared according to the present invention.
As can be seen from fig. 5, random results from high resolution field emission transmission electron microscopy of graphene were characterized.
Example 3
5g of expanded graphite is subjected to ultrasonic treatment for 80min at the frequency of 2000Hz, then is subjected to sanding for 60min at the rotating speed of 3000r/min, and is homogenized for 5min under the condition of 120MPa to obtain an intermediate.
Then the intermediate and concentrated sulfuric acid and hydrogen peroxide are mixed according to the following ratio of 1:40:1, carrying out intercalation stripping on the mass ratio, drying the intercalated sample, and carrying out thermal expansion treatment at 1000 ℃ for 10min to obtain the thin-layer graphene microchip aggregate.
Referring to fig. 6, fig. 6 is a high-magnification SEM scanning electron microscope image of the graphene microchip aggregate prepared in example 3 of the present invention.
As can be seen from fig. 6, the graphene microplates on the graphene microplate aggregate have a wrinkled morphology, and the plurality of graphene microplates are stacked in a layered manner and in a staggered manner, the thickness of the graphene microplates is about 5 to 8nm, and the plate diameter of the graphene microplates is about 1 to 10 μm.
And (3) putting the graphene microchip aggregate into high-purity water, and carrying out ultrasonic treatment for 120min under the condition of 3000Hz to strip again to obtain the graphene microchip.
Then according to the thin-layer graphene microplates: and (3) carrying out a secondary intercalation experiment on the potassium sodium tartrate tetrahydrate=1:1 ratio, wherein the temperature of the secondary intercalation water bath is divided into three stages, namely, the first stage is 40 ℃, the second stage is 60 ℃, the heat preservation is carried out for 30min, the heat preservation is carried out for 60min, the third stage is 90 ℃, the heat preservation is carried out for 30min, when the temperature of the solution is reduced to room temperature, secondary ultrasonic assisted stripping is carried out, the stripping time is 80min, and the obtained graphene mixed solution after stripping is washed by water for 2-5 times, so as to obtain a graphene aqueous solution.
The graphene prepared in example 3 of the present invention was characterized.
Referring to fig. 7, fig. 7 is an infrared spectrogram of graphene prepared by the present invention.
As can be seen from fig. 7, the graphene prepared by the method has low defect degree, and the infrared spectrum shows that the surface has no grafted functional group.
The graphene microchip aggregate, the preparation method thereof and the preparation method of the high-concentration graphene aqueous solution provided by the invention are described in detail, and specific examples are applied to illustrate the principles and the implementation modes of the invention, and the description of the examples is only used for helping understand the method and the core ideas of the invention, including the best mode, and also enables any person skilled in the art to practice the invention, including making and using any device or system and implementing any combined method. It should be noted that it will be apparent to those skilled in the art that various modifications and adaptations of the invention can be made without departing from the principles of the invention and these modifications and adaptations are intended to be within the scope of the invention as defined in the following claims. The scope of the patent protection is defined by the claims and may include other embodiments that occur to those skilled in the art. Such other embodiments are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
Claims (10)
1. The graphene microchip aggregate is characterized by being formed by aggregating graphene microchip;
the graphene microchip aggregate has a layered structure on microcosmic scale;
the graphene sheet aggregate has a layered stack structure along a single direction and a direction perpendicular to the single direction;
interlayer gaps are formed between layers of the graphene microchip aggregate;
the distance between the interlayer gaps is 10-20 mu m;
the graphene microchip has a wrinkled shape;
the graphene microplates are stacked in layers and/or staggered;
the thickness of the graphene microchip is 5-8 nm.
2. The graphene microchip aggregate of claim 1, wherein the graphene microchip aggregate has a layered structure of a rock stack;
the graphene microchip aggregate is a micron-sized material.
3. The graphene microchip aggregate of claim 1, wherein the thickness of the graphene aggregate is 200-500 μm;
the radial dimension of the graphene aggregate is 0.1-2 mm;
and the sheet diameter of the graphene micro-sheet is 1-10 mu m.
4. A method for preparing the graphene microchip aggregate according to any one of claims 1 to 3, comprising the following steps:
1) Ultrasonic grinding and homogenizing are carried out on the expanded graphite to obtain an intermediate;
2) And (3) carrying out intercalation reaction on the intermediate, the acid and the oxidant obtained in the steps, and then carrying out thermal expansion treatment to obtain the graphene microchip aggregate.
5. The preparation method according to claim 4, wherein the ultrasonic time is 10-120 min;
the frequency of the ultrasonic wave is 1000-3000 Hz;
the grinding mode comprises sanding;
the grinding time is 20-80 min;
the grinding rotating speed is 1000-3000 r/min;
the homogenizing pressure is 30-120 MPa;
the homogenizing time is 5-20 min;
the acid includes one or more of sulfuric acid, phosphoric acid, hydrochloric acid, nitric acid, perchloric acid, aqua regia, carbonic acid, formic acid, acetic acid and hydrofluoric acid.
6. The method according to claim 4, wherein the oxidizing agent comprises one or more of potassium permanganate, hydrogen peroxide, potassium dichromate, fuming sulfuric acid, ozone, chlorine gas and sodium ferrate;
the mass ratio of the intermediate to the acid is 1: (10-100);
the mass ratio of the intermediate to the oxidant is 1: (1-5);
the time of the intercalation reaction is 1-3 h;
the temperature of the intercalation reaction is 20-50 ℃;
The intercalation reaction is followed by a drying step;
the temperature of the thermal expansion treatment is 900-1100 ℃;
the time of the thermal expansion treatment is 10-60 min.
7. The preparation method of the graphene aqueous solution is characterized by comprising the following steps of:
a) Re-stripping the graphene microchip aggregate and performing small molecular compound intercalation reaction, and then carrying out assisted stripping and water washing to obtain a graphene aqueous solution;
the graphene microchip aggregate is the graphene microchip aggregate according to any one of claims 1 to 3 or the graphene microchip aggregate prepared by the preparation method according to any one of claims 4 to 6.
8. The method according to claim 7, wherein the re-peeling means comprises water bath ultrasonic treatment and/or ultrasonic bar treatment;
the time for re-stripping is 60-120 min;
the frequency of the re-stripping is 1000-3000 Hz;
the small molecule compound comprises a metal small molecule compound;
the temperature of the intercalation reaction is 30-90 ℃;
the time of the intercalation reaction is 60-180 min;
the graphene is low-defect graphene.
9. The method of claim 8, wherein the means for assisting in exfoliation comprises ultrasonic assisted exfoliation;
The water washing mode comprises ultrasonic water washing;
the mass ratio of the graphene microchip aggregate to the micromolecular compound is (1-2): 1, a step of;
the metal small molecular compound comprises one or more of potassium sodium tartrate tetrahydrate, sodium sulfate decahydrate, magnesium acetate tetrahydrate, sodium carbonate, sodium bicarbonate, ferric chloride, lithium nitrate, lithium oxalate, lithium formate, lithium carbonate, calcium chloride and calcium phosphate;
the intercalation reaction comprises the following specific steps:
preserving heat for 10-30 min at 30-40 ℃ in the first stage, preserving heat for 30-60 min at 50-60 ℃ in the second stage, and preserving heat for 20-30 min at 80-90 ℃ in the third stage;
the ultrasonic stripping-assisting mode comprises water bath ultrasonic stripping-assisting and/or ultrasonic rod stripping-assisting;
the graphene is nanoscale graphene.
10. The method for preparing the adhesive according to claim 9, wherein the ultrasonic assisted stripping time is 60-120 min;
the ultrasonic stripping-assisting frequency is 1000-3000 Hz;
the washing process further comprises a separation step;
the separation mode comprises one or more of a centrifugation method, a sedimentation method and a ceramic membrane filtration method;
the concentration of the graphene aqueous solution is 0.1% -10%;
the number of the graphene sheets is less than or equal to 10;
The sheet diameter of the graphene is 1-5 mu m;
the defect degree of the graphene is that the Id/Ig value of the Raman spectrum is smaller than 0.1.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3404061A (en) * | 1962-03-21 | 1968-10-01 | Union Carbide Corp | Flexible graphite material of expanded particles compressed together |
| CN104058396A (en) * | 2014-07-14 | 2014-09-24 | 复旦大学 | Method for preparing large-size high-quality graphene with controllable number of layers |
| CN104386680A (en) * | 2014-11-14 | 2015-03-04 | 沙嫣 | Method for large-scale preparation of bulky graphene |
| CN105293476A (en) * | 2015-11-16 | 2016-02-03 | 复旦大学 | Preparation method of large-size graphene oxide or graphene |
| CN107840327A (en) * | 2016-09-21 | 2018-03-27 | 比亚迪股份有限公司 | A kind of graphene aggregation composite material and its preparation method and application |
| CN109650385A (en) * | 2019-01-19 | 2019-04-19 | 深圳市国创珈伟石墨烯科技有限公司 | A kind of high-purity high stable watersoluble plumbago alkene slurry of super-small and preparation method thereof |
| CN109665518A (en) * | 2017-10-16 | 2019-04-23 | 山东欧铂新材料有限公司 | A kind of preparation method of highly conductive graphene |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10787365B2 (en) * | 2016-01-18 | 2020-09-29 | King Abdullah University Of Science And Technology | Expansion and exfoliation of graphite to form graphene |
-
2020
- 2020-10-27 CN CN202011166341.8A patent/CN114477148B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3404061A (en) * | 1962-03-21 | 1968-10-01 | Union Carbide Corp | Flexible graphite material of expanded particles compressed together |
| CN104058396A (en) * | 2014-07-14 | 2014-09-24 | 复旦大学 | Method for preparing large-size high-quality graphene with controllable number of layers |
| CN104386680A (en) * | 2014-11-14 | 2015-03-04 | 沙嫣 | Method for large-scale preparation of bulky graphene |
| CN105293476A (en) * | 2015-11-16 | 2016-02-03 | 复旦大学 | Preparation method of large-size graphene oxide or graphene |
| CN107840327A (en) * | 2016-09-21 | 2018-03-27 | 比亚迪股份有限公司 | A kind of graphene aggregation composite material and its preparation method and application |
| CN109665518A (en) * | 2017-10-16 | 2019-04-23 | 山东欧铂新材料有限公司 | A kind of preparation method of highly conductive graphene |
| CN109650385A (en) * | 2019-01-19 | 2019-04-19 | 深圳市国创珈伟石墨烯科技有限公司 | A kind of high-purity high stable watersoluble plumbago alkene slurry of super-small and preparation method thereof |
Non-Patent Citations (3)
| Title |
|---|
| 杨永清等.石墨及其改性产物研究进展.《材料导报》.2011,(第15期), * |
| 石墨及其改性产物研究进展;杨永清等;《材料导报》;20110810(第15期);第3-57页 * |
| 膨胀石墨制备石墨烯的可行性研究;崔汶静等;《前沿科学》;20110928(第03期);第42-49页 * |
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