Three-dimensional graphene / polypyrrole / nano-silver composite material as well as preparation method and application thereof

Abstract

The invention discloses a three-dimensional graphene / polypyrrole / nano-silver composite material as well as a preparation method and application thereof, and relates to the technical field of electromagnetic shielding materials. In-situ preparation of three-dimensional graphene, polypyrrole and nano-silver is performed on a carbon-containing substrate by utilizing a high-energy beam induction preparation technology; the advantages of the three materials of the three-dimensional graphene, the polypyrrole and the nano-silver are fully exerted, a large number of heterogeneous interfaces are provided, multiple loss mechanisms are coupled, and application in the field of electromagnetic shielding is achieved. And the preparation method provided by the invention has the advantages of low cost, simple process, greenness, environmental protection and the like, and has relatively high popularization value.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic shielding materials, and in particular to a three-dimensional graphene / polypyrrole / nanosilver composite material and a preparation method and application thereof. Background Art

[0002] With the progress of human society and the continuous development of productivity, various electronic equipment and instruments have greatly improved the quality of human life, but at the same time have also brought some negative effects. The electromagnetic waves generated by electronic and communication equipment not only affect the normal operation of electronic equipment, but also cause harm to the human body. The barrier formed by conductive materials and magnetic materials can effectively block or dissipate electromagnetic waves. With the vigorous development of electronic information technology, under the new development opportunities, higher requirements are put forward for the development of electromagnetic shielding materials.

[0003] As traditional shielding materials, metal-based materials (such as nickel, iron, copper, silver and their alloys) are used in the field of electromagnetic shielding due to their high electrical conductivity and ability to effectively reflect electromagnetic waves. However, metals are heavy, not easy to corrode, and not easy to process. More importantly, the electromagnetic waves reflected into free space will cause secondary electromagnetic wave pollution. In contrast, conductive polymers (such as polyaniline and polypyrrole) have attracted great attention in the field of electromagnetic shielding due to their multiple advantages such as low density, easy processing, adjustable absorption frequency and wide absorption bandwidth. However, the improvement of the conductivity of conductive polymers is limited and cannot meet the application requirements of high-performance electromagnetic shielding. With the development trend of integration and miniaturization of electronic equipment, higher requirements are placed on the "light, thin and tough" characteristics of electromagnetic shielding materials. Three-dimensional graphene has good dielectric properties and a typical hierarchical porous structure, which is conducive to multiple internal reflections of electromagnetic waves, promotes the absorption and dissipation of electromagnetic waves, and shows broad application prospects in the field of electromagnetic shielding. However, the loss mechanism of three-dimensional graphene alone is single, and it is difficult to achieve high shielding effectiveness. By utilizing the hierarchical porous structure of three-dimensional graphene, combining the heterogeneous interface provided by metal nanoparticles and conductive polymers, and coupling multiple loss mechanisms, high-efficiency electromagnetic shielding performance can be effectively achieved. However, in the actual preparation process, the simultaneous in-situ composite of three-dimensional graphene, conductive polymers and metal nanoparticles still faces challenges. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for preparing a three-dimensional graphene / polypyrrole / nanosilver composite material, focusing on solving the problem of synchronous in-situ preparation of polypyrrole and nanosilver in three-dimensional graphene, and successfully applying the obtained three-dimensional graphene / polypyrrole / nanosilver composite material to the field of electromagnetic shielding.

[0005] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:

[0006] The first object of the present invention is to provide a method for preparing a three-dimensional graphene / polypyrrole / nanosilver composite material, comprising the following steps:

[0007] (1) treating the carbon-containing substrate to be hydrophilic;

[0008] (2) using a high energy beam to irradiate the hydrophilic treated carbon-containing substrate to obtain hydrophilic three-dimensional porous graphene;

[0009] (3) loading pyrrole and silver salt onto the hydrophilic three-dimensional porous graphene by an impregnation method;

[0010] (4) Using high energy beam to irradiate hydrophilic three-dimensional porous graphene loaded with pyrrole and silver salt, a three-dimensional graphene / polypyrrole / nanosilver composite material is obtained.

[0011] The second object of the present invention is to provide a three-dimensional graphene / polypyrrole / nanosilver composite material prepared by the aforementioned preparation method.

[0012] The third object of the present invention is to provide the use of the aforementioned three-dimensional graphene / polypyrrole / nanosilver composite material in electromagnetic shielding.

[0013] The beneficial effects of the present invention are as follows: the present invention utilizes high-energy beam induced preparation technology to carry out in-situ preparation of three-dimensional graphene, polypyrrole and nano-silver on a carbon-containing polymer, giving full play to the advantages of the three-dimensional graphene, polypyrrole and nano-silver materials, providing a large number of heterogeneous interfaces, coupling multiple loss mechanisms, and realizing application in the field of electromagnetic shielding; and the preparation method provided by the present invention has many advantages such as low cost, simple process, green environmental protection, etc., and has high promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a scanning electron microscope image of the three-dimensional graphene / polypyrrole / nanosilver composite material prepared in Example 1 of the present invention;

[0015] Figure 2 This is a graph showing the electromagnetic shielding performance of the three-dimensional graphene / polypyrrole / nanosilver composite material prepared in Example 1 of the present invention; wherein SE T , SE A , SE R They represent the total electromagnetic shielding effectiveness, absorption effectiveness and reflection effectiveness respectively. DETAILED DESCRIPTION

[0016] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific embodiments and diagrams.

[0017] The present invention provides a method for preparing a three-dimensional graphene / polypyrrole / nanosilver composite material, comprising the following steps:

[0018] (1) treating the carbon-containing substrate to be hydrophilic;

[0019] (2) using a high energy beam to irradiate the hydrophilic treated carbon-containing substrate to obtain hydrophilic three-dimensional porous graphene;

[0020] (3) loading pyrrole and silver salt onto the hydrophilic three-dimensional porous graphene by an impregnation method;

[0021] (4) A three-dimensional graphene / polypyrrole / nanosilver composite material is obtained by irradiating a hydrophilic three-dimensional porous graphene loaded with pyrrole and silver salt using a high energy beam.

[0022] Furthermore, the carbon-containing substrate includes but is not limited to at least one of polyimide, polyurethane, polyamide, polyamic acid, polyetheretherketone, polyether, polyester, polyethersulfone, polyetherimide, polyethylene, polystyrene, polyvinyl chloride, polysulfide rubber, phenolic resin, and epoxy resin.

[0023] Furthermore, the high-energy beam irradiation is performed by first designing a pattern on a computer-side CAD software, and then placing the hydrophilic treated carbon-containing substrate and the hydrophilic three-dimensional porous graphene loaded with pyrrole and silver salt on a vacuum adsorption platform for high-energy beam irradiation.

[0024] Furthermore, the high-energy beam includes but is not limited to at least one of a laser beam, an electron beam, and an ion beam.

[0025] Furthermore, the wavelength of the high-energy beam is 500nm-100μm, the power is 4-20W, the scanning speed is 100-300mm / s, the scanning interval is 100-300μm, and the spot size is 10-100nm.

[0026] Furthermore, the hydrophilic treatment is to immerse the carbon-containing substrate in an acidic or alkaline solution.

[0027] Furthermore, the acidic solution includes but is not limited to at least one of hydrochloric acid, sulfuric acid, nitric acid, hydrobromic acid, and hydroiodic acid; the alkaline solution includes but is not limited to at least one of potassium hydroxide solution, sodium hydroxide solution, and barium hydroxide solution.

[0028] Furthermore, the silver salt includes but is not limited to at least one of silver nitrate, silver sulfate and silver halide. Under the irradiation of the high energy beam, the pyrrole is oxidatively polymerized to polypyrrole due to the oxidation of silver ions, and the silver ions are carbon-thermally reduced to silver nanoparticles due to the photothermal effect after being irradiated by the high energy beam.

[0029] The present invention provides a three-dimensional graphene / polypyrrole / nanosilver composite material prepared by the above-mentioned preparation method.

[0030] The present invention also provides the use of the above three-dimensional graphene / polypyrrole / nanosilver composite material in electromagnetic shielding.

[0031] Example 1

[0032] 1. Preparation of three-dimensional porous graphene:

[0033] A polyimide film with a thickness of 150 μm was selected and immersed in a 2 mol / L dilute sulfuric acid solution for 1 hour. After being taken out and dried, it was placed on a vacuum adsorption platform and irradiated in situ using a CO2 infrared laser. The laser wavelength was 10.6 μm, the laser power was 7 W, the laser scanning speed was 170 mm / s, the laser scanning interval was 150 μm, and the laser spot diameter was 50 nm to obtain hydrophilic three-dimensional porous graphene.

[0034] 2. Preparation of three-dimensional graphene / polypyrrole / nanosilver composite materials:

[0035] The prepared hydrophilic three-dimensional graphene was immersed in a mixed solution of pyrrole and silver nitrate for 2 hours, wherein the contents of pyrrole and silver nitrate in the mixed solution were 0.5 mol / L and 0.8 mol / L, respectively. After being taken out and dried, it was placed on a vacuum adsorption platform and irradiated in situ using a CO2 infrared laser with a laser wavelength of 10.6 μm, a laser power of 8 W, a laser scanning speed of 160 mm / s, a laser scanning interval of 130 μm, and a laser spot diameter of 50 nm to obtain a three-dimensional graphene / polypyrrole / nanosilver composite material.

[0036] Example 2

[0037] Example 2 The method for preparing a three-dimensional graphene / polypyrrole / nanosilver composite material is the same as that of Example 1, except that the contents of pyrrole and silver nitrate are 1 mol / L and 1.3 mol / L, respectively.

[0038] Example 3

[0039] Example 3 The method for preparing a three-dimensional graphene / polypyrrole / nanosilver composite material is the same as that of Example 1, except that the contents of pyrrole and silver nitrate are 1.5 mol / L and 1.8 mol / L, respectively.

[0040] Example 4

[0041] Example 4 The method for preparing a three-dimensional graphene / polypyrrole / nanosilver composite material is the same as that of Example 1, except that a polyethersulfone film is used as the carbon-containing substrate.

[0042] Example 5

[0043] Example 5 The method for preparing a three-dimensional graphene / polypyrrole / nanosilver composite material is the same as that of Example 1, except that the laser power is 10 W, the laser scanning speed is 200 mm / s, the laser scanning interval is 120 μm, and the laser spot diameter is 80 nm.

[0044] Comparative Example 1

[0045] Comparative Example 1 only adopts the method of Example 1 to prepare three-dimensional porous graphene (without hydrophilic treatment), and does not compound with polypyrrole and nanosilver. The remaining steps are the same as those of Example 1.

[0046] Comparative Example 2

[0047] Comparative Example 2 The method for preparing three-dimensional porous graphene is the same as that of Example 1, but it is only immersed in a 0.8 mol / L silver nitrate solution to obtain a three-dimensional graphene / nanosilver composite material.

[0048] Comparative Example 3

[0049] Comparative Example 3 is a polypyrrole / silver / graphene oxide composite material prepared according to the method of Example 1 in patent CN111768976A.

[0050] The electromagnetic shielding performance of the composite materials prepared in the above embodiments and comparative examples was tested in the X-band (8.2-12.4 GHz) using a vector grid analyzer (VNA, N5244A). The results are shown in Table 1.

[0051] Table 1 Electromagnetic shielding properties of composite materials

[0052]

[0053]

[0054] It can be seen from Table 1 that the three-dimensional graphene / polypyrrole / nanosilver composite material prepared by the present invention has excellent electromagnetic shielding performance, and the polypyrrole and nanosilver generated in situ in the three-dimensional graphene structure are more conducive to improving the electromagnetic shielding performance.

[0055] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for preparing a three-dimensional graphene / polypyrrole / nanosilver composite material, characterized in that: The following steps are involved: (1) treating the carbon-containing substrate to be hydrophilic; (2) using a high energy beam to irradiate the hydrophilic treated carbon-containing substrate to obtain hydrophilic three-dimensional porous graphene; (3) loading pyrrole and silver salt onto the hydrophilic three-dimensional porous graphene by an impregnation method; (4) Using high energy beam to irradiate hydrophilic three-dimensional porous graphene loaded with pyrrole and silver salt, a three-dimensional graphene / polypyrrole / nanosilver composite material is obtained.

2. The preparation method according to claim 1, characterized in that: The carbon-containing substrate is at least one of polyimide, polyurethane, polyamide, polyamic acid, polyetheretherketone, polyether, polyester, polyethersulfone, polyetherimide, polyethylene, polystyrene, polyvinyl chloride, polysulfide rubber, phenolic resin, and epoxy resin.

3. The preparation method according to claim 1, characterized in that: The high-energy beam irradiation is to first design a pattern on a computer-side CAD software, and then place the carbon-containing substrate after hydrophilic treatment and the hydrophilic three-dimensional porous graphene loaded with pyrrole and silver salt on a vacuum adsorption platform for high-energy beam irradiation.

4. The preparation method according to claim 1, characterized in that: The high energy beam is at least one of a laser beam, an electron beam and an ion beam.

5. The preparation method according to claim 4, characterized in that: The wavelength of the high-energy beam is 500nm-100μm, the power is 4-20W, the scanning speed is 100-300mm / s, the scanning interval is 100-300μm, and the spot size is 10-100nm.

6. The preparation method according to claim 1, characterized in that: The hydrophilic treatment is to immerse the carbon-containing substrate in an acidic or alkaline solution.

7. The preparation method according to claim 6, characterized in that: The acidic solution is at least one of hydrochloric acid, sulfuric acid, nitric acid, hydrobromic acid, and hydroiodic acid; the alkaline solution is at least one of potassium hydroxide solution, sodium hydroxide solution, and barium hydroxide solution.

8. The preparation method according to claim 1, characterized in that: The silver salt is at least one of silver nitrate, silver sulfate and silver halide.

9. A three-dimensional graphene / polypyrrole / nanosilver composite material prepared by the preparation method according to claims 1 to 8.

10. Use of the three-dimensional graphene / polypyrrole / nanosilver composite material according to claim 9 in electromagnetic shielding.

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