CN110040724B - Preparation method of folded graphene and electromagnetic shielding material thereof - Google Patents
Preparation method of folded graphene and electromagnetic shielding material thereof Download PDFInfo
- Publication number
- CN110040724B CN110040724B CN201910435618.3A CN201910435618A CN110040724B CN 110040724 B CN110040724 B CN 110040724B CN 201910435618 A CN201910435618 A CN 201910435618A CN 110040724 B CN110040724 B CN 110040724B
- Authority
- CN
- China
- Prior art keywords
- graphene
- electromagnetic shielding
- shielding material
- folded
- graphene oxide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
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
- C01B32/184—Preparation
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/02—Elements
- C08K3/04—Carbon
- C08K3/042—Graphene or derivatives, e.g. graphene oxides
-
- 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 relates to a preparation method of folded graphene, which comprises the following steps: (1) mixing the graphene oxide dispersion liquid with ascorbic acid and hydroiodic acid to obtain a mixed solution; (2) and (3) heating the mixed solution obtained in the step (1) to obtain the folded graphene. According to the invention, under the synergistic effect of ascorbic acid and hydroiodic acid, graphene oxide is efficiently reduced, and the obtained graphene has a good fold structure, and the fold structure can effectively inhibit stacking of graphene nanosheets, so that more fluffy graphene powder is obtained, and the density is low; the folded graphene powder is easier to filter out from the reduced dispersion liquid, the problem that the graphene powder is difficult to separate in practical application is solved, and the production efficiency is greatly improved; meanwhile, the wrinkled surface of the graphene sheet layer is beneficial to enhancing the shielding effect of the electromagnetic waves.
Description
Technical Field
The invention belongs to the field of electromagnetic shielding materials, and particularly relates to a preparation method of folded graphene and an electromagnetic shielding material thereof.
Background
With the rapid development and precision improvement of modern electronic products, the electromagnetic radiation pollution is more and more serious. The development of high-performance electromagnetic shielding materials is an effective means for relieving electromagnetic interference, secret leakage and human health hazards caused by electromagnetic wave pollution. The graphene with the two-dimensional planar structure has incomparable performances such as ultrahigh electrical conductivity, excellent heat conduction and mechanical properties, and an oversized theoretical specific surface area, and is an ideal material for preparing electromagnetic shielding materials. The graphene/polymer electromagnetic shielding composite material prepared by filling the graphene powder into the polymer has the advantages of light weight, corrosion resistance, easiness in processing, adjustable performance and the like, and is favored. However, the graphene-based electromagnetic shielding material usually requires a high graphene powder filling amount (10 to 30 wt%) for realizing a shielding performance of 20dB for commercial application, and has a thickness of 2 to 4 mm. The high filling amount not only reduces the mechanical property of the composite material, but also greatly increases the preparation cost of the material, and limits the application of the graphene-based electromagnetic shielding material. The essential reason is that stacking of graphene is easy to occur due to strong interaction between sheets in the reduction process, and graphene powder is easy to agglomerate in a polymer, so that the effectiveness of graphene as a high-performance filler is reduced.
The folded graphene is formed on the surface of the graphene, so that stacking and agglomeration of the graphene can be effectively inhibited, and the folded graphene shows more excellent conductivity. The existing methods for preparing the folded graphene include a spray drying method and a template method. In the former method, graphene oxide in a wrinkled form is formed by surface wrinkling after water is lost from a graphene oxide dispersion liquid through a spray drying method, and then the wrinkled graphene is obtained through a high-temperature thermal reduction method. The technology has high dependence on equipment, harsh conditions and high energy consumption by adopting high-temperature thermal reduction. The template method is to distribute graphene oxide on a substrate template and to produce a wrinkled morphology on the surface of a graphene sheet layer by wrinkling the template, and requires a substrate template and is troublesome to operate.
CN105694427A discloses an application of graphene composite material as electromagnetic shielding material, belonging to the technical field of new materials and application thereof. Graphene and foam sponge are compounded, so that graphene materials are uniformly coated on the surface of a foam sponge framework, and the graphene composite material with the isotropic and three-dimensionally communicated conductive network framework is prepared. The performance of the electromagnetic shielding material prepared by the method cannot meet the performance requirement of an excellent electromagnetic shielding material.
CN104883868B discloses a preparation method of a magnetic material/graphene paper composite material for electromagnetic shielding, belonging to the field of electromagnetic shielding. According to the method, graphene with a complete structure and high conductivity is prepared by a liquid phase stripping method, then a magnetic material precursor is uniformly dispersed in a graphene suspension, an alkaline solution is added, and a magnetic material uniformly grows on a graphene sheet layer by a hydrothermal method, so that the magnetic material/graphene paper composite material for electromagnetic shielding is obtained. The method has complex preparation process and poor electromagnetic shielding performance.
Therefore, there is a need in the art to develop a simple and efficient graphene preparation method, and the prepared graphene has good electromagnetic shielding performance when applied to the field of electromagnetic shielding.
Disclosure of Invention
The invention aims to provide a preparation method of folded graphene and an electromagnetic shielding material thereof, wherein the uneven surface morphology of the folded graphene is beneficial to realizing the scattering of electromagnetic waves and improving the electromagnetic shielding performance of a graphene-based electromagnetic shielding material.
The folds are super folds which have more fold structures compared with graphene in the prior art.
In order to achieve the purpose, the invention adopts the following technical scheme:
one of the purposes of the present invention is to provide a preparation method of folded graphene, which comprises the following steps:
(1) mixing the graphene oxide dispersion liquid with ascorbic acid and hydroiodic acid to obtain a mixed solution;
(2) and (3) heating the mixed solution obtained in the step (1) to obtain the folded graphene.
According to the invention, under the synergistic effect of ascorbic acid and hydroiodic acid, graphene oxide is efficiently reduced, and the obtained graphene has a good fold structure, and the fold structure can effectively inhibit stacking of graphene nanosheets, so that more fluffy graphene powder is obtained, and the density is low; the folded graphene powder is easier to filter out from the reduced dispersion liquid, the problem that the graphene powder is difficult to separate in practical application is solved, and the production efficiency is greatly improved; meanwhile, the wrinkled surface of the graphene sheet layer is beneficial to enhancing the shielding effect of the electromagnetic waves.
The preparation method of the folded graphene does not need specific equipment and harsh conditions, is simple and efficient, and is green and pollution-free.
Preferably, the mass ratio of the graphene oxide, the ascorbic acid and the hydroiodic acid in the step (1) is 1: 1-20, preferably 1: 5-10, such as 1:2:5, 1:5:5, 1:8:2, 1:5:10, 1:10:8, 1:8:12, 1:10:10, 1:12:10, 1:15:5, 1:16:4, 1:10:15, 1:13:8 or 1:18: 5.
The mass ratio of the graphene oxide to the ascorbic acid to the hydroiodic acid is 1: 1-20, graphene with a good fold structure can be obtained within the range, and the fold structure of the graphene obtained beyond the range is poor, so that the performance of the graphene is affected.
Preferably, the concentration of the graphene oxide dispersion liquid in the step (1) is 1-3 mg/mL, preferably 1.5-2.5 mg/mL, such as 1.2mg/mL, 1.4mg/mL, 1.5mg/mL, 1.8mg/mL, 2.0mg/mL, 2.2mg/mL, 2.5mg/mL or 2.8 mg/mL.
When the concentration of the graphene oxide dispersion liquid is less than 1mg/mL, the interaction between graphene oxide lamella is weak, the mutual connection is difficult to cause the lamella to wrinkle, and the pi-pi action between the reduced graphene lamella is greatly enhanced, so that the graphene is stacked; when the concentration of the graphene oxide dispersion liquid is more than 3mg/mL, the interlayer spacing of graphene nanosheets is reduced, the peeling dispersion is poor, and the interaction between the sheets is strong, so that the sheets are attracted to each other to be stacked, and the folded graphene cannot be formed.
Preferably, the mixing time in step (1) is 0.2-0.6 h, such as 0.3h, 0.4h or 0.5 h.
Preferably, the preparation process of the graphene oxide dispersion liquid in the step (1) comprises; and carrying out chemical oxidation, stripping and centrifugation on graphite to obtain the graphene oxide dispersion liquid.
The graphene oxide dispersion liquid is prepared by a conventional method, and is exemplarily prepared by a Hummers method.
Preferably, the mesh size of the graphite is >300 mesh, such as 320 mesh, 350 mesh, 400 mesh, 450 mesh, 500 mesh, 550 mesh, 600 mesh, 700 mesh or 800 mesh, etc.
When the mesh number of the graphite is less than 300 meshes, the particle size of the raw material graphite is larger, the graphene oxide obtained by chemical oxidation has large lamellar size and strong interaction among laminas, the oxygen-containing functional groups at the edges are removed to cause the laminas to be difficult to wrinkle, and finally the graphene exists in a stacking form.
Preferably, the graphene oxide dispersion has an average lateral dimension of graphene oxide lamellae <20 μm, e.g. 5 μm, 8 μm, 10 μm, 12 μm, 15 μm, 18 μm, etc.
According to the invention, the average transverse size of the graphene oxide lamella is controlled by regulating the mesh number of graphite, and if the average transverse size of the graphene oxide lamella is more than or equal to 20 μm, the finally obtained graphene has a poor folded structure and exists in a lamella mutual stacking structure.
Preferably, the heating temperature in step (2) is 70-98 ℃, such as 72 ℃, 75 ℃, 78 ℃, 80 ℃, 82 ℃, 85 ℃, 88 ℃, 90 ℃, 92 ℃ or 95 ℃.
Preferably, the heating time is 2-4 h, such as 2.2h, 2.5h, 2.8h, 3h, 3.2h, 3.5h or 3.8 h.
Preferably, the heating is heating under stirring.
Preferably, the mixed solution further comprises the processes of filtering, washing and drying after being heated.
Preferably, the drying includes any one or a combination of at least two of freeze drying, air drying and natural airing.
As a preferred technical scheme, the preparation method of the folded graphene comprises the following steps:
(1) carrying out chemical oxidation, stripping and centrifugation on graphite larger than 300 meshes to obtain graphene oxide dispersion liquid, wherein the average transverse size of graphene oxide sheets in the graphene oxide dispersion liquid is less than 20 micrometers;
(2) mixing 1.5-2.5 mg/mL of the graphene oxide dispersion liquid with ascorbic acid and hydroiodic acid for 0.2-0.6 h, wherein the mass ratio of the graphene oxide to the ascorbic acid to the hydroiodic acid is 1: 5-10, and thus obtaining a mixed solution;
(3) heating the mixed solution obtained in the step (2) for 2-4 hours at 70-98 ℃ under the stirring condition, filtering, washing, and freeze-drying to obtain the folded graphene.
The second purpose of the present invention is to provide a folded graphene prepared by the method of the first purpose, wherein the microscopic surface of the folded graphene nanosheet is in a folded morphological distribution.
The third purpose of the present invention is to provide a use of the folded graphene according to the second purpose, wherein the folded graphene is applied to the field of electromagnetic shielding materials and/or energy storage.
The fourth purpose of the present invention is to provide an electromagnetic shielding material, which includes the second purpose of providing the folded graphene.
Preferably, the electromagnetic shielding material further comprises a polymer.
Preferably, the raw material of the polymer is a polymer monomer and/or a polymer prepolymer.
Preferably, the polymer monomer comprises any one of polyvinyl alcohol, epoxy resin, polystyrene, polyethylene, polypropylene, polyimide, ethylene propylene rubber, polyurethane, polycarbonate, polymethyl methacrylate and polyamide or a combination of at least two of the same.
Preferably, the polymer prepolymer is any one or a combination of at least two of resin, rubber, polymer fiber or polymer adhesive.
Preferably, the content of the folded graphene in the electromagnetic shielding material is 1-10 wt%, such as 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt% or 9 wt%.
Preferably, the thickness of the electromagnetic shielding material is 0.5-2 mm, such as 0.6mm, 0.8mm, 1mm, 1.2mm, 1.4mm, 1.5mm, 1.6mm or 1.8 mm.
The electromagnetic shielding material disclosed by the invention can obtain excellent electromagnetic shielding performance under the conditions of low graphene consumption and low thickness, and the electromagnetic shielding efficiency can reach 28 dB.
The fifth purpose of the present invention is to provide a method for preparing an electromagnetic shielding material, comprising the following steps: dispersing the folded graphene in the second purpose in a polymer monomer or a polymer prepolymer, and carrying out in-situ polymerization to obtain an electromagnetic shielding material;
or dispersing the folded graphene in the second purpose in a molten mass of a polymer monomer or a polymer prepolymer, and performing melt blending to obtain the electromagnetic shielding material;
or dispersing the folded graphene in the solution containing the polymer monomer or the polymer prepolymer, uniformly mixing, and removing the solvent to obtain the electromagnetic shielding material.
Compared with the prior art, the invention has the following beneficial effects:
(1) according to the invention, under the synergistic effect of ascorbic acid and hydroiodic acid, graphene oxide is efficiently reduced, and the obtained graphene has a good fold structure, and the fold structure can effectively inhibit stacking of graphene nanosheets, so that more fluffy graphene powder is obtained, and the density is low; the folded graphene powder is easier to filter out from the reduced dispersion liquid, the problem that the graphene powder is difficult to separate in practical application is solved, and the production efficiency is greatly improved; meanwhile, the wrinkled surface of the graphene sheet layer is beneficial to enhancing the shielding effect of the electromagnetic waves.
(2) The preparation method of the super-folded graphene does not need specific equipment and harsh conditions, can realize the preparation of the super-folded graphene through regulating and controlling the mass ratio of the graphene oxide, the ascorbic acid and the hydroiodic acid, the concentration of the graphene oxide, the size of a sheet layer and the reduction reaction conditions, and is simple, efficient, green and pollution-free.
(3) The electromagnetic shielding material disclosed by the invention can obtain excellent electromagnetic shielding performance under the conditions of low thickness and low graphene consumption, and the electromagnetic shielding efficiency can reach 28 dB.
Drawings
Fig. 1 is a scanning electron microscope image of the wrinkled graphene obtained in example 1;
FIG. 2 is an optical image of the electromagnetic shielding material obtained in example 1;
fig. 3 is a scanning electron microscope image of the stacked graphene obtained in comparative example 1;
fig. 4 is optical images of the graphenes of example 1 and comparative example 1, where (a) is the optical image of 0.2g of the folded graphene obtained in example 1, and (b) is the optical image of 0.2g of the stacked graphene obtained in comparative example 1.
Detailed Description
For the purpose of facilitating an understanding of the present invention, the present invention will now be described by way of examples. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.
Example 1
The preparation method of the electromagnetic shielding material comprises the following steps:
(1) preparing graphene oxide from 325-mesh natural crystalline flake graphite by adopting an improved Hummers method to obtain graphene oxide dispersion liquid, wherein the average transverse size of graphene oxide sheets in the graphene oxide dispersion liquid is 15 micrometers;
(2) mixing 2.5mg/mL of the graphene oxide dispersion liquid with ascorbic acid and hydroiodic acid for 0.5h, wherein the mass ratio of the graphene oxide to the ascorbic acid to the hydroiodic acid is 1:10:8, so as to obtain a mixed solution;
(3) heating the mixed solution obtained in the step (2) for 2.5h at 90 ℃ under the stirring condition, filtering, washing, freezing and drying to obtain graphene, observing the obtained graphene by using a scanning electron microscope, wherein the surface appearance of the obtained graphene is shown in figure 1, and the surface of the graphene powder can be seen to be in a highly wrinkled form; fig. 4 (a) is an optical image of the graphene, and it can be seen that, in example 1, (a) the volume of the folded graphene powder is more than 3 times that of the stacked graphene powder in comparative example 1(b), which indicates that the folded graphene has a bulkier structure, and when the filtration is performed by using a buchner funnel, (a) the folded graphene powder is easier to separate, and the filtration speed is increased by more than 20 times compared with (b) the stacked graphene;
(4) dissolving 90g of polyvinyl alcohol 1799 in hot water at 90 ℃, adding 10g of graphene obtained in the step (3), stirring for 2h, mixing, then placing in a culture dish, drying in vacuum at 40 ℃, and completely volatilizing the solvent to obtain the electromagnetic shielding material with the thickness of 1.0mm, wherein the electromagnetic shielding material is shown in figure 2.
Example 2
The difference from example 1 is that the natural crystalline flake graphite in step (1) is 400 mesh, and the average transverse dimension of graphene oxide sheets in the graphene dispersion liquid is 10 μm.
Example 3
The difference from example 1 is that the concentration of the graphene oxide dispersion liquid in the step (2) is 1.5 mg/mL.
Example 4
The difference from example 1 is that the concentration of the graphene oxide dispersion liquid in the step (2) is 1 mg/mL.
Example 5
The difference from example 1 is that the concentration of the graphene oxide dispersion liquid in the step (2) is 2 mg/mL.
Example 6
The difference from the example 1 is that the mass ratio of the graphene oxide, the ascorbic acid and the hydroiodic acid in the step (2) is 1:0.5: 25.
Example 7
The difference from the example 1 is that the mass ratio of the graphene oxide, the ascorbic acid and the hydroiodic acid in the step (2) is 1:25: 0.1.
Example 8
The preparation method of the electromagnetic shielding material comprises the following steps:
(1) preparing graphene oxide from 300-mesh artificial graphite by adopting a Hummers method to obtain a graphene oxide dispersion liquid, wherein the average transverse size of graphene oxide sheets in the graphene oxide dispersion liquid is 17 micrometers;
(2) mixing 2.5mg/mL of the graphene oxide dispersion liquid with ascorbic acid and hydroiodic acid for 0.2h, wherein the mass ratio of the graphene oxide to the ascorbic acid to the hydroiodic acid is 1:10:10, and obtaining a mixed solution;
(3) heating the mixed solution obtained in the step (2) for 4 hours at 70 ℃ under the condition of stirring, filtering, washing, and naturally drying to obtain graphene;
(4) and (4) dispersing 1g of graphene obtained in the step (3) in 99g of rubber melt, and carrying out melt blending to obtain the electromagnetic shielding material with the thickness of 1.0 mm.
Comparative example 1
The difference from example 1 is that in step (2) the ascorbic acid and hydroiodic acid are replaced by an equal mass of hydrazine hydrate. Observing the obtained graphene by a scanning electron microscope, wherein the surface appearance of the obtained graphene is as shown in fig. 3, and it can be seen from the figure that the surface of the graphene powder is in a flat stacking state, and graphene nanosheets are stacked seriously; fig. 4 (b) is an optical image of the graphene, and it can be seen from the image that the volume of the wrinkled graphene powder (a) obtained in example 1 is more than 3 times that of the stacked graphene powder (b) in comparative example 1, which indicates that the wrinkled graphene has a bulkier structure, and when the filtration is performed by using a buchner funnel, the wrinkled graphene powder (a) is easier to separate, and the filtration speed is increased by more than 20 times compared with the stacked graphene (b).
Comparative example 2
The difference from example 1 is that the ascorbic acid in step (2) is replaced by an equal mass of hydroiodic acid, i.e. no ascorbic acid is added.
Comparative example 3
The difference from example 1 is that the hydriodic acid in step (2) is replaced by ascorbic acid of equal mass, i.e. no hydriodic acid is added.
Comparative example 4
The difference from example 1 is that the heating process of step (3) is not performed.
And (3) performance testing:
and (3) carrying out performance test on the prepared graphene and the electromagnetic shielding material:
(1) surface morphology: and observing the surface morphology of the obtained graphene by adopting a scanning electron microscope.
(2) Electromagnetic shielding effectiveness: the prepared electromagnetic shielding material is tested for electromagnetic shielding effectiveness in the frequency range of 8.2-12.4 GHz.
TABLE 1
As can be seen from table 1, in comparison with example 1, in example 2, graphene oxide is synthesized by using graphite with a smaller particle size, and since the obtained graphene oxide nanosheets are small in size and most of oxygen-containing functional groups are distributed on the edge, the fold effect caused in the reduction process is more obvious to the nanosheets, and graphene with a fold shape can be obtained.
In the embodiments 3, 4 and 5, the graphene with the folded shape can be obtained within the range of the concentration of the graphene oxide of 1-3 mg/mL, the folded structure is more obvious along with the increase of the concentration within the range, and the electromagnetic shielding of the material is improved.
In example 6, the amount of ascorbic acid used was too low, the reduction effect was poor, the wrinkle morphology was difficult to form, and the graphene stacking was significant; in example 7, the amount of hydroiodic acid used was reduced, the repair of graphene oxide nanosheets and the removal of oxygen-containing functional groups were reduced, and although graphene having a wrinkled morphology could be obtained, the conductivity thereof was inferior to that of the graphene obtained in example 1, and thus the performance of the electromagnetic shielding material prepared using the same as a filler was reduced.
In the comparative example 1, hydrazine hydrate is used as a reducing agent, the graphene sheet layers are stacked seriously, and the electromagnetic shielding performance of the composite material is low; in the comparative example 2, ascorbic acid is not added, and graphene with a fold structure cannot be obtained by simple hydroiodic acid reduction; in the comparative example 3, hydroiodic acid is not added for reduction, so that the reduction degree of graphene is reduced, the conductivity is reduced, and the electromagnetic shielding performance of the composite material is reduced; in comparative example 4, the reduction process was not heated, the reduction effect was poor, the lamellar wrinkle morphology was difficult to form, and the electromagnetic shielding performance of the material prepared with it as a filler was poor.
The applicant states that the present invention is illustrated by the above examples to show the detailed process equipment and process flow of the present invention, but the present invention is not limited to the above detailed process equipment and process flow, i.e. it does not mean that the present invention must rely on the above detailed process equipment and process flow to be implemented. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.
Claims (20)
1. A preparation method of folded graphene is characterized by comprising the following steps:
(1) carrying out chemical oxidation, stripping and centrifugation on graphite with the mesh number of more than 300 meshes to obtain graphene oxide dispersion liquid, wherein the concentration of the graphene oxide dispersion liquid is 1-3 mg/mL, and the average transverse size of graphene oxide lamella in the graphene oxide dispersion liquid is less than 20 micrometers;
mixing the graphene oxide dispersion liquid with ascorbic acid and hydroiodic acid, wherein the mass ratio of the graphene oxide to the ascorbic acid to the hydroiodic acid is 1: 1-20, and obtaining a mixed solution; the mixing time is 0.2-0.6 h;
(2) and (3) heating the mixed solution obtained in the step (1) to obtain the folded graphene.
2. The preparation method according to claim 1, wherein the mass ratio of the graphene oxide, the ascorbic acid and the hydroiodic acid in the step (1) is 1:5 to 10.
3. The preparation method according to claim 1, wherein the concentration of the graphene oxide dispersion liquid in the step (1) is 1.5-2.5 mg/mL.
4. The method according to claim 1, wherein the heating temperature in the step (2) is 70 to 98 ℃.
5. The method according to claim 4, wherein the heating time is 2 to 4 hours.
6. The method according to claim 4, wherein the heating is heating under stirring.
7. The method according to claim 1, wherein the step (2) of heating the mixed solution further comprises the steps of filtering, washing and drying.
8. The method of claim 7, wherein the drying comprises any one of freeze-drying, air-drying and air-drying or a combination of at least two of them.
9. The method of claim 1, comprising the steps of:
(1) carrying out chemical oxidation, stripping and centrifugation on graphite larger than 300 meshes to obtain graphene oxide dispersion liquid, wherein the average transverse size of graphene oxide lamella in the graphene oxide dispersion liquid is less than 20 micrometers;
(2) mixing 1.5-2.5 mg/mL of the graphene oxide dispersion liquid with ascorbic acid and hydroiodic acid for 0.2-0.6 h, wherein the mass ratio of the graphene oxide to the ascorbic acid to the hydroiodic acid is 1: 5-10, and thus obtaining a mixed solution;
(3) heating the mixed solution obtained in the step (2) for 2-4 hours at 70-98 ℃ under the stirring condition, filtering, washing, and freeze-drying to obtain the folded graphene.
10. The folded graphene prepared by the method of any one of claims 1 to 9, wherein the microscopic surface of the folded graphene nanosheet is in a folded morphological distribution;
the folds can effectively inhibit stacking of graphene nanosheets;
the folds are beneficial to enhancing the shielding effect of the electromagnetic waves.
11. Use of the folded graphene according to claim 10, wherein the folded graphene is applied to an electromagnetic shielding material.
12. An electromagnetic shielding material, wherein the electromagnetic shielding material comprises the folded graphene of claim 10.
13. The electromagnetic shielding material of claim 12 further comprising a polymer, wherein the polymer is a monomer and/or prepolymer.
14. The electromagnetic shielding material of claim 13 wherein said polymer comprises any one or a combination of at least two of polyvinyl alcohol, epoxy, polystyrene, polyethylene, polypropylene, polyimide, ethylene propylene rubber, polyurethane, polycarbonate, polymethyl methacrylate, and polyamide.
15. The electromagnetic shielding material of claim 13 wherein the polymer prepolymer is any one or a combination of at least two of a resin, a rubber, a polymer fiber, or a polymer adhesive.
16. The electromagnetic shielding material of claim 13, wherein the amount of folded graphene in the electromagnetic shielding material is 1 to 10 wt%.
17. The electromagnetic shielding material of claim 13, wherein the thickness of the electromagnetic shielding material is 0.5 to 2 mm.
18. The preparation method of the electromagnetic shielding material is characterized by comprising the following steps of: dispersing the folded graphene according to claim 11 in a polymer monomer or a polymer prepolymer, and carrying out in-situ polymerization to obtain the electromagnetic shielding material.
19. The preparation method of the electromagnetic shielding material is characterized by comprising the following steps of: dispersing the folded graphene according to claim 11 in a melt of a polymer monomer or a polymer prepolymer, and performing melt blending to obtain the electromagnetic shielding material.
20. The preparation method of the electromagnetic shielding material is characterized by comprising the following steps of: dispersing the folded graphene according to claim 11 in a solution containing a polymer monomer or a polymer prepolymer, mixing uniformly, and removing the solvent to obtain the electromagnetic shielding material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910435618.3A CN110040724B (en) | 2019-05-23 | 2019-05-23 | Preparation method of folded graphene and electromagnetic shielding material thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910435618.3A CN110040724B (en) | 2019-05-23 | 2019-05-23 | Preparation method of folded graphene and electromagnetic shielding material thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110040724A CN110040724A (en) | 2019-07-23 |
| CN110040724B true CN110040724B (en) | 2021-08-24 |
Family
ID=67283378
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910435618.3A Active CN110040724B (en) | 2019-05-23 | 2019-05-23 | Preparation method of folded graphene and electromagnetic shielding material thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110040724B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110395716A (en) * | 2019-07-26 | 2019-11-01 | 中国电子科技集团公司第三十三研究所 | A kind of preparation method of the microwave defense material based on graphene |
| CN110436445B (en) * | 2019-08-20 | 2021-03-09 | 中国科学院城市环境研究所 | Single-layer folded graphene and preparation method and application thereof |
| CN113443619B (en) * | 2021-08-13 | 2023-02-17 | 中国科学院城市环境研究所 | Device system for preparing single-layer graphene, single-layer graphene and preparation method of single-layer graphene |
| CN114789997A (en) * | 2022-03-21 | 2022-07-26 | 成都飞机工业（集团）有限责任公司 | Preparation method of mesoporous reduced graphene oxide absorbent |
| CN116375012A (en) * | 2023-04-21 | 2023-07-04 | 华能新能源股份有限公司 | Two-dimensional graphene and preparation method and application thereof |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105967172A (en) * | 2016-05-06 | 2016-09-28 | 电子科技大学 | Preparation method of foldable graphene thin film of large area |
| CN106185905A (en) * | 2016-07-15 | 2016-12-07 | 浙江大学 | A kind of pure Graphene composite electromagnetic screen film and preparation method thereof |
| CN106241777A (en) * | 2016-07-15 | 2016-12-21 | 浙江大学 | A kind of high resiliency graphene paper |
| CN107200992A (en) * | 2017-06-21 | 2017-09-26 | 长兴德烯科技有限公司 | A kind of ABS composite material of graphene toughness reinforcing and preparation method thereof |
| CN107381544A (en) * | 2017-06-16 | 2017-11-24 | 中国科学院福建物质结构研究所 | A kind of graphene film and its preparation method and application |
| CN107555419A (en) * | 2017-10-13 | 2018-01-09 | 杭州高烯科技有限公司 | A kind of low corrugation density graphene film and preparation method thereof |
| CN108794812A (en) * | 2018-06-25 | 2018-11-13 | 厦门中科城环新能源有限公司 | A kind of electromagnetic shielding material and its preparation method and application |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101216052B1 (en) * | 2010-12-10 | 2012-12-27 | 국립대학법인 울산과학기술대학교 산학협력단 | Method of preparing nitrogen-doped graphene and nitrogen-doped graphene prepared thereby |
| KR101754208B1 (en) * | 2015-03-30 | 2017-07-07 | 한국세라믹기술원 | A method for enhancing graphen folding line |
| CN107107052A (en) * | 2015-11-11 | 2017-08-29 | 沙特基础工业全球技术公司 | The multiple function stable nanometer tectosome of hydrotalcite shell containing nano-sized carbon and nanostructured or micrometer structure and through calcining |
-
2019
- 2019-05-23 CN CN201910435618.3A patent/CN110040724B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105967172A (en) * | 2016-05-06 | 2016-09-28 | 电子科技大学 | Preparation method of foldable graphene thin film of large area |
| CN106185905A (en) * | 2016-07-15 | 2016-12-07 | 浙江大学 | A kind of pure Graphene composite electromagnetic screen film and preparation method thereof |
| CN106241777A (en) * | 2016-07-15 | 2016-12-21 | 浙江大学 | A kind of high resiliency graphene paper |
| CN107381544A (en) * | 2017-06-16 | 2017-11-24 | 中国科学院福建物质结构研究所 | A kind of graphene film and its preparation method and application |
| CN107200992A (en) * | 2017-06-21 | 2017-09-26 | 长兴德烯科技有限公司 | A kind of ABS composite material of graphene toughness reinforcing and preparation method thereof |
| CN107555419A (en) * | 2017-10-13 | 2018-01-09 | 杭州高烯科技有限公司 | A kind of low corrugation density graphene film and preparation method thereof |
| CN108794812A (en) * | 2018-06-25 | 2018-11-13 | 厦门中科城环新能源有限公司 | A kind of electromagnetic shielding material and its preparation method and application |
Non-Patent Citations (3)
| Title |
|---|
| "高导电石墨烯的化学制备及其性能研究";20190430;《精细化工中间体》;20190430;第49卷(第2期);第48-52页 * |
| 20190430."高导电石墨烯的化学制备及其性能研究".《精细化工中间体》.2019,第49卷(第2期), * |
| Impermeable barrier films and protective coatings based on reduced graphene oxide;Y. Su1 et al.;《NATURE COMMUNICATIONS》;20140911;第1-5页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110040724A (en) | 2019-07-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110040724B (en) | Preparation method of folded graphene and electromagnetic shielding material thereof | |
| Chen et al. | Porous aerogel and sponge composites: Assisted by novel nanomaterials for electromagnetic interference shielding | |
| Chen et al. | Synergistically assembled MWCNT/graphene foam with highly efficient microwave absorption in both C and X bands | |
| Liang et al. | Ultralight, flexible carbon hybrid aerogels from bacterial cellulose for strong microwave absorption | |
| CN105110318B (en) | A kind of graphene water paste and preparation method thereof | |
| Ji et al. | Remarkable microwave absorption performance of ultralight graphene-polyethylene glycol composite aerogels with a very low loading ratio of graphene | |
| Sun et al. | Effective improvement on microwave absorbing performance of epoxy resin-based composites with 3D MXene foam prepared by one-step impregnation method | |
| CN103977748B (en) | A kind of magnetic aeroge and preparation method thereof | |
| CN102533216B (en) | Ferroferric oxide/reduced graphene oxide composite wave-absorbing material with hollow hemisphere structure and preparation method | |
| CN109301184A (en) | Modified composite material, preparation method and the purposes in lithium ion battery of siliceous substrates material | |
| CN106410155B (en) | A kind of preparation method of graphene silica carbon negative pole material | |
| CN108003364B (en) | Flexible graphene-based composite membrane, preparation method thereof and application of flexible graphene-based composite membrane as electromagnetic shielding material | |
| CN104973591B (en) | High-quality graphene and preparation method thereof | |
| WO2012062110A1 (en) | Preparing method of composite lithium iron phosphate/carbon for lithium ion battery | |
| CN108342036B (en) | Magnetic Mxenes polymer composite wave-absorbing material and preparation method thereof | |
| CN102145888A (en) | Preparation method of grapheme three-dimensional entity | |
| CN113462357A (en) | Wave-absorbing particles and preparation method and application of composite material thereof | |
| CN107393622B (en) | Graphene-titanium suboxide composite conductive agent and preparation method thereof | |
| CN109637840B (en) | NiFe2O4/carbon nano sheet composite material and preparation method thereof | |
| CN104108700A (en) | Graphene material powder and preparation method | |
| CN111589435A (en) | Porous reduction-oxidation (carbon nano tube/graphene) nano material and preparation method and application thereof | |
| CN111732743A (en) | Preparation method of carbon nanotube/graphene flexible film | |
| Pai et al. | Nanocellulose-based sustainable microwave absorbers to stifle electromagnetic pollution | |
| Chen et al. | Design of 3D lightweight Ti3C2Tx MXene porous film with graded holes for efficient electromagnetic interference shielding performance | |
| CN113512215B (en) | Graphene-based flexible electromagnetic wave shielding film and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB02 | Change of applicant information | ||
| CB02 | Change of applicant information |
Address after: 361012 627a, No. 581, tonglong 2nd Road, industrial zone, torch high tech Zone (Xiang'an), Xiamen City, Fujian Province Applicant after: Kecharan (Xiamen) New Materials Co.,Ltd. Applicant after: ZKCH Co.,Ltd. Address before: 361021 20th floor 2024, Innovation Building, 1300 Jimei Avenue, Xiamen City, Fujian Province Applicant before: Kecharan (Xiamen) New Materials Co.,Ltd. Applicant before: ZKCH Co.,Ltd. |
|
| GR01 | Patent grant | ||
| GR01 | Patent grant |