CN113956532B - Millimeter wave absorbing material and preparation method and application thereof - Google Patents
Millimeter wave absorbing material and preparation method and application thereof Download PDFInfo
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- CN113956532B CN113956532B CN202111319295.5A CN202111319295A CN113956532B CN 113956532 B CN113956532 B CN 113956532B CN 202111319295 A CN202111319295 A CN 202111319295A CN 113956532 B CN113956532 B CN 113956532B
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
- C08J9/36—After-treatment
- C08J9/365—Coating
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
- C08J9/36—After-treatment
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q17/00—Devices for absorbing waves radiated from an antenna; Combinations of such devices with active antenna elements or systems
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K9/00—Screening of apparatus or components against electric or magnetic fields
- H05K9/0073—Shielding materials
- H05K9/0081—Electromagnetic shielding materials, e.g. EMI, RFI shielding
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2325/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring; Derivatives of such polymers
- C08J2325/02—Homopolymers or copolymers of hydrocarbons
- C08J2325/04—Homopolymers or copolymers of styrene
- C08J2325/06—Polystyrene
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- Microelectronics & Electronic Packaging (AREA)
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- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
- Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
The invention discloses a millimeter wave absorbing material which has a core-shell structure, wherein the core is polystyrene foam microspheres, and the shell is polyaniline. The millimeter wave absorbing material has the characteristics of light weight, excellent wave absorbing performance and excellent suspension characteristic, and has a good application prospect in the aspects of absorbing shielding and smoke screen interference. The invention also discloses a preparation method and application of the millimeter wave absorbing material.
Description
Technical Field
The invention relates to the technical field of wave-absorbing materials and smoke screen interference. And more particularly, to a millimeter wave absorbing material, a method for preparing the same, and applications thereof.
Background
The millimeter wave is an electromagnetic wave between microwave and light wave, and the frequency band of the millimeter wave is usually 30 to 300GHz, and the corresponding wavelength is 1 to 10mm. With the rapid development of millimeter wave technology application, passive interference technology (i.e. interference cloud formed by suspending interfering particles in the air to be implemented, including absorption and scattering) with features of simplicity, rapidness, high efficiency-cost ratio and low price becomes an important research direction for millimeter wave countermeasure. In China, smoke screen technology research starts late, the foundation is weak, and related applications are still few. One of the important issues is to study a wave-absorbing material having a significant attenuation in the millimeter wave band. Over the years, domestic researchers have studied the millimeter wave interference performance of millimeter wave foil strips/sheets, chopped carbon fibers, aluminized hollow glass fibers, expanded graphite and other materials, and the results show that the materials still have certain defects in the interference effect or practicability at present, and the distance index still has a certain distance. Therefore, it is desirable to provide a wave-absorbing material having excellent attenuation characteristics in the millimeter wave band.
Disclosure of Invention
Based on the defects, the invention provides a millimeter wave absorbing material, and a preparation method and application thereof, so as to at least solve the problem that the prior art does not have a good wave absorbing material with excellent attenuation characteristics in millimeter wave bands.
On one hand, the invention provides a millimeter wave absorbing material which has a core-shell structure, wherein the core is a polystyrene foam microsphere, and the shell is polyaniline.
The millimeter wave smoke screen interference material with excellent performance meets two conditions: firstly, the material has certain conductivity, so that incident waves can be more easily subjected to multistage scattering and attenuation; secondly, the particle size should be increased to millimeter level and have good suspension performance. According to the quarter wavelength principle, the interference material has to have a relatively large particle size due to a long millimeter wave wavelength, and the particles with a small size have a good suspension capacity, so that how to solve the contradiction becomes a research focus and a technical key of the millimeter wave interference material.
In order to solve the contradiction, the technical scheme of the invention utilizes the polystyrene foam microspheres which are common in the market and very light as the carriers to coat the polyaniline with the semiconductor property on the surface of the carriers, so that the polyaniline has certain conductivity and solves the contradiction that the particle size is large and the particle size has suspension property.
It is also understood that the composition of the material comprises polystyrene foam microspheres and polyaniline; in the material, the polyaniline coats the polystyrene foam microspheres.
Further, the millimeter wave absorbing material is spherical particles or approximately spherical particles, and the particle size is 0.5-2mm.
Further, the polystyrene foam microspheres are polystyrene foam microspheres.
Further, the polystyrene foam microspheres are sulfonated polystyrene foam microspheres.
Further, in the material, the thickness of the shell is 0.1-0.5mm. Too thick a shell can lead to peeling of the coating and too thin a shell can lead to incomplete coating.
In another aspect, the present invention provides a method for preparing a millimeter wave absorbing material according to the first object, comprising the steps of:
sulfonating the polystyrene foam microspheres;
mixing the sulfonated polystyrene foam microspheres with water and aniline to obtain a mixed solution;
adding an aqueous solution of an oxidant into the mixed solution, and uniformly mixing;
and washing and drying to obtain the millimeter wave absorbing material.
Further, the mass ratio of the polystyrene foam microspheres to the aniline is 1: (2-10).
Further, the molar ratio of the oxidant to the aniline is (1-2): 1.
further, the oxidizing agent includes, but is not limited to, selected from ammonium sulfate.
Further, mixing the sulfonated polystyrene foam microspheres with water and aniline, and stirring at 0-20 ℃ to obtain the mixed solution.
Further, the sulfonation process comprises the steps of:
mixing the polystyrene foam microspheres with concentrated sulfuric acid solution, and stirring for 2-4 hours at 80-120 ℃;
and taking out the polystyrene foam microspheres, and washing until the pH value is 5-7 to obtain the sulfonated polystyrene foam microspheres.
Further, the oxidant is any one of ammonium persulfate, potassium dichromate and hydrogen peroxide.
In yet another aspect, the present invention provides the use of a millimeter wave absorbing material as described in the first object above for millimeter wave absorbing shielding and smoke screen interference.
Further, the millimeter wave wavelength is 3mm or 8 mm.
Unless otherwise specified, the raw materials comprising the polystyrene foam microspheres in the present invention are commercially available.
The invention has the following beneficial effects:
the millimeter wave absorbing material provided by the invention has the characteristics of light weight, excellent wave absorbing performance and excellent suspension property. In the millimeter wave absorbing material, the styrene foam microspheres are taken as cores, and the suspension property of the material is ensured due to the characteristic of light weight; the polyaniline is a shell, and due to the characteristics of a semiconductor, the excellent wave-absorbing interference characteristic of the material is ensured; the polyaniline-coated polystyrene foam microspheres ensure the effective absorption of the material to millimeter waves due to the millimeter-sized dimension. In addition, the preparation method of the millimeter wave absorbing material is quick and simple in equipment. The millimeter wave absorbing material has good application prospect in the aspects of absorbing shielding and smoke screen interference, particularly has the attenuation value of-63 dB at the lowest in a 3mm electromagnetic wave static shielding test, and shows excellent millimeter wave attenuation characteristic; the minimum attenuation value in a static test of 8mm electromagnetic wave interference performance reaches-14.7 dB, and the excellent millimeter wave attenuation characteristic is embodied.
Drawings
The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.
Fig. 1 shows an optical microscope photograph of the millimeter wave absorbing material obtained in example 1 at each stage of the production process.
Fig. 2 shows the wave absorption attenuation curve of the millimeter wave absorbing material obtained in example 1 in the 3mm waveband.
Fig. 3 shows the wave absorption attenuation curve of the millimeter wave absorbing material obtained in example 1 in the 8mm waveband.
Fig. 4 shows an optical micrograph of the millimeter wave absorbing material obtained in example 2 after coating.
Fig. 5 shows the wave-absorbing attenuation curve of the millimeter wave absorbing material obtained in example 2 in the 3mm wave band.
Fig. 6 shows the wave-absorbing attenuation curve of the millimeter wave absorbing material obtained in example 2 in the 8mm waveband.
Fig. 7 shows an optical micrograph of the millimeter wave absorbing material obtained in example 3 after coating.
Detailed Description
In order to more clearly illustrate the present invention, the present invention is further described below with reference to preferred embodiments and the accompanying drawings. Similar components in the figures are denoted by the same reference numerals. It is to be understood by persons skilled in the art that the following detailed description is illustrative and not restrictive, and is not to be taken as limiting the scope of the invention.
Example 1
Preparing a millimeter wave absorbing material:
1) Adding 0.2g of polystyrene foam beads (shown as a in figure 1) with the particle size of 1.5-2.5mm into 55mL of concentrated sulfuric acid solution, and continuously stirring for 2.5 hours at 100 ℃;
2) Fishing out the pellets, washing with distilled water for 2-3 times to ensure that the PH is 5-7 to obtain sulfonated polystyrene pellets (shown as b in figure 1);
3) Adding sulfonated polystyrene beads into 25mL of water, then adding 0.63mL of aniline, and stirring for 15 minutes at 0-20 ℃;
4) Dissolving 2.85g of ammonium persulfate in 25mL of water, adding the mixture in the step 3) into the mixed solution, stopping stirring, and standing for 12 hours to obtain undried polyaniline-coated polystyrene spheres (as shown in a figure 1 c);
5) Washing with water and ethanol for several times, respectively, and vacuum drying at 60 deg.C for 12h to obtain polyaniline-coated polystyrene spheres (shown as d in FIG. 1) with particle diameter of 0.5-2mm.
And (3) performance testing:
the millimeter wave absorption material obtained by the embodiment is subjected to a millimeter wave static shielding test, and the minimum attenuation value in a 3mm electromagnetic wave interference performance static test reaches-63 dB (as shown in figure 2), so that excellent millimeter wave attenuation characteristics are embodied; the minimum attenuation value in the static test of the 8mm electromagnetic wave interference performance reaches-14.7 dB (as shown in figure 3), and the better millimeter wave attenuation characteristic is shown.
Example 2
Preparing a millimeter wave absorbing material:
1) Adding 0.1g of polystyrene foam small balls with the particle size of 1.5-2.5mm into 30mL of concentrated sulfuric acid solution, and continuously stirring for 4 hours at 80 ℃;
2) Fishing out the pellets, washing with distilled water for 2-3 times to ensure that the PH is 5-7 to obtain sulfonated polystyrene pellets;
3) Adding the sulfonated polystyrene pellets into 25mL of water, then adding 0.8mL of aniline, and stirring for 15 minutes at 0-20 ℃;
4) Dissolving 1.6g of ammonium persulfate in 25mL of water, adding the mixture in the step 3) into the mixed solution, stopping stirring, and standing for 12 hours to obtain undried polyaniline-coated polystyrene spheres (shown in figure 4);
5) Washing with water and ethanol for several times, respectively, and vacuum drying at 60 deg.C for 12 hr to obtain polyaniline-coated polystyrene spheres with particle diameter of 0.5-2mm.
And (3) performance testing:
according to the method of the embodiment 1, the millimeter wave absorption material obtained in the embodiment is subjected to a millimeter electromagnetic wave static shielding test, and the attenuation value in the 3mm electromagnetic wave interference performance static test is as low as-41.6 dB (as shown in figure 5), so that the millimeter wave absorption material shows excellent millimeter wave attenuation characteristics; the minimum attenuation value in the static test of the 8mm electromagnetic wave interference performance reaches-20.2 dB (as shown in figure 6), and the better millimeter wave attenuation characteristic is shown.
Example 3
Preparing a millimeter wave absorbing material:
1) Adding 0.1g of polystyrene foam small balls with the particle size of 1.5-2.5mm into 30mL of concentrated sulfuric acid solution, and continuously stirring for 2 hours at 120 ℃;
2) Fishing out the pellets, washing with distilled water for 2-3 times to ensure that the PH is 5-7 to obtain sulfonated polystyrene pellets;
3) Adding sulfonated polystyrene beads into 25mL of water, then adding 0.2mL of aniline, and stirring for 15 minutes at 0-20 ℃;
4) Dissolving 0.14g of hydrogen peroxide in 25mL of water, adding the mixture in 3) and stopping stirring and standing for 12 hours to obtain undried polyaniline-coated polystyrene spheres (shown in figure 7);
5) Washing with water and ethanol for several times, respectively, and vacuum drying at 60 deg.C for 12 hr to obtain polyaniline-coated polystyrene spheres with particle diameter of 0.5-2mm.
And (4) performance testing:
according to the method of the embodiment 1, the millimeter wave absorption material obtained by the embodiment is subjected to a millimeter electromagnetic wave static shielding test, and the attenuation value in the 3mm electromagnetic wave interference performance static test is as low as-11.1 dB, so that a certain millimeter wave attenuation characteristic is embodied; the minimum attenuation value in a static test of 8mm electromagnetic wave interference performance reaches-9.1 dB, and certain millimeter wave attenuation characteristic is embodied.
It should be understood that the above-described embodiments of the present invention are examples for clearly illustrating the invention, and are not to be construed as limiting the embodiments of the present invention, and it will be obvious to those skilled in the art that various changes and modifications can be made on the basis of the above description, and it is not intended to exhaust all embodiments, and obvious changes and modifications can be made on the basis of the technical solutions of the present invention.
Claims (10)
1. The millimeter wave absorbing material is characterized by having a core-shell structure, wherein the core is polystyrene foam microspheres, and the shell is polyaniline.
2. The millimeter wave absorbing material according to claim 1, wherein the millimeter wave absorbing material is spherical particles or substantially spherical particles having a particle diameter of 0.5 to 2mm.
3. The millimeter wave absorbing material according to claim 1, wherein the polystyrene foam microspheres are sulfonated polystyrene foam microspheres.
4. The millimeter wave absorbing material according to claim 1 or 2, wherein the thickness of the shell is 0.1 to 0.5mm.
5. The method for producing a millimeter wave absorbing material according to any one of claims 1 to 4, comprising the steps of:
sulfonating the polystyrene foam microspheres;
mixing the sulfonated polystyrene foam microspheres with water and aniline to obtain a mixed solution;
adding an aqueous solution of an oxidant into the mixed solution, and uniformly mixing;
and washing and drying to obtain the millimeter wave absorbing material.
6. The method of claim 5, wherein the sulfonation process comprises the steps of:
mixing the polystyrene foam microspheres with concentrated sulfuric acid solution, and stirring for 2-4 hours at 80-120 ℃;
and taking out the polystyrene foam microspheres, and washing until the pH value is 5-7 to obtain the sulfonated polystyrene foam microspheres.
7. The method of claim 5, wherein the sulfonated polystyrene foam microspheres are mixed with water and aniline, and then stirred at 0-20 ℃ to obtain the mixed solution.
8. The preparation method according to claim 5, wherein the oxidant is any one of ammonium persulfate, potassium dichromate and hydrogen peroxide.
9. Use of the millimeter wave absorbing material of any of claims 1 to 4 in millimeter wave absorption shielding and smoke screen interference.
10. Use according to claim 9, characterized in that the millimeter wave wavelength is 3mm or 8 mm.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11209505A (en) * | 1998-01-23 | 1999-08-03 | Mitsubishi Cable Ind Ltd | Electroconductive expanded particle, its production and wave absorber |
| CN102702636A (en) * | 2012-06-14 | 2012-10-03 | 南京大学 | Polystyrene/polyaniline/magnetic nanoparticle composite particle and preparation method thereof |
| CN103740233A (en) * | 2014-01-08 | 2014-04-23 | 南京信息工程大学 | Micrometer wave absorbing coating material and preparation method thereof |
| CN105315565A (en) * | 2015-11-27 | 2016-02-10 | 湖北大学 | Sulfonated polystyrene/polyaniline/nano silver compound microsphere and preparation method thereof |
| CN105504337A (en) * | 2016-01-20 | 2016-04-20 | 武汉理工大学 | Attapulgite clay/polyanion/polystyrene composite particle and preparation method thereof |
| CN110256847A (en) * | 2019-06-18 | 2019-09-20 | 同济大学 | Polyaniline/carbon foam composite preparation method with controllable absorbing property |
-
2021
- 2021-11-09 CN CN202111319295.5A patent/CN113956532B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11209505A (en) * | 1998-01-23 | 1999-08-03 | Mitsubishi Cable Ind Ltd | Electroconductive expanded particle, its production and wave absorber |
| CN102702636A (en) * | 2012-06-14 | 2012-10-03 | 南京大学 | Polystyrene/polyaniline/magnetic nanoparticle composite particle and preparation method thereof |
| CN103740233A (en) * | 2014-01-08 | 2014-04-23 | 南京信息工程大学 | Micrometer wave absorbing coating material and preparation method thereof |
| CN105315565A (en) * | 2015-11-27 | 2016-02-10 | 湖北大学 | Sulfonated polystyrene/polyaniline/nano silver compound microsphere and preparation method thereof |
| CN105504337A (en) * | 2016-01-20 | 2016-04-20 | 武汉理工大学 | Attapulgite clay/polyanion/polystyrene composite particle and preparation method thereof |
| CN110256847A (en) * | 2019-06-18 | 2019-09-20 | 同济大学 | Polyaniline/carbon foam composite preparation method with controllable absorbing property |
Non-Patent Citations (2)
| Title |
|---|
| "High frequency millimeter wave absorbers deriverd from polymeric nanocomposites";Shital et al.;《Polymer》;20160210;第84卷;398-419 * |
| "Trapping of microwave radiation in hollow polypyrrole microsphere through enhanced internal reflection: A novel approach";Ritwik Panigrahi et al.;《SCIENTIFIC REPORTS》;20150106;第5卷;7638 * |
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