CN114696112A - Hollow glass bead/ferroferric oxide/carbon wave-absorbing powder and preparation method thereof - Google Patents
Hollow glass bead/ferroferric oxide/carbon wave-absorbing powder and preparation method thereof Download PDFInfo
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- CN114696112A CN114696112A CN202011602976.8A CN202011602976A CN114696112A CN 114696112 A CN114696112 A CN 114696112A CN 202011602976 A CN202011602976 A CN 202011602976A CN 114696112 A CN114696112 A CN 114696112A
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- ferroferric oxide
- silicon dioxide
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- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 98
- 229910052799 carbon Inorganic materials 0.000 title claims abstract description 98
- 239000000843 powder Substances 0.000 title claims abstract description 86
- 238000002360 preparation method Methods 0.000 title claims abstract description 64
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 207
- 239000000377 silicon dioxide Substances 0.000 claims abstract description 104
- 235000012239 silicon dioxide Nutrition 0.000 claims abstract description 99
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- 229920000128 polypyrrole Polymers 0.000 claims abstract description 34
- KAESVJOAVNADME-UHFFFAOYSA-N Pyrrole Chemical compound C=1C=CNC=1 KAESVJOAVNADME-UHFFFAOYSA-N 0.000 claims abstract description 30
- 239000003513 alkali Substances 0.000 claims abstract description 15
- 239000003054 catalyst Substances 0.000 claims abstract description 13
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- 235000013855 polyvinylpyrrolidone Nutrition 0.000 claims description 21
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- NWZSZGALRFJKBT-KNIFDHDWSA-N (2s)-2,6-diaminohexanoic acid;(2s)-2-hydroxybutanedioic acid Chemical compound OC(=O)[C@@H](O)CC(O)=O.NCCCC[C@H](N)C(O)=O NWZSZGALRFJKBT-KNIFDHDWSA-N 0.000 claims description 13
- IKDUDTNKRLTJSI-UHFFFAOYSA-N hydrazine monohydrate Substances O.NN IKDUDTNKRLTJSI-UHFFFAOYSA-N 0.000 claims description 13
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 12
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 claims description 12
- 239000012153 distilled water Substances 0.000 claims description 12
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- 238000001132 ultrasonic dispersion Methods 0.000 claims description 12
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- 229910021578 Iron(III) chloride Inorganic materials 0.000 claims description 10
- 239000002585 base Substances 0.000 claims description 10
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 claims description 10
- 238000002156 mixing Methods 0.000 claims description 10
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- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 9
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- 239000012792 core layer Substances 0.000 claims description 9
- HZAXFHJVJLSVMW-UHFFFAOYSA-N 2-Aminoethan-1-ol Chemical compound NCCO HZAXFHJVJLSVMW-UHFFFAOYSA-N 0.000 claims description 6
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- 239000002131 composite material Substances 0.000 claims description 5
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- KWSLGOVYXMQPPX-UHFFFAOYSA-N 5-[3-(trifluoromethyl)phenyl]-2h-tetrazole Chemical compound FC(F)(F)C1=CC=CC(C2=NNN=N2)=C1 KWSLGOVYXMQPPX-UHFFFAOYSA-N 0.000 claims description 3
- ZBCBWPMODOFKDW-UHFFFAOYSA-N diethanolamine Chemical compound OCCNCCO ZBCBWPMODOFKDW-UHFFFAOYSA-N 0.000 claims description 3
- XMYQHJDBLRZMLW-UHFFFAOYSA-N methanolamine Chemical compound NCO XMYQHJDBLRZMLW-UHFFFAOYSA-N 0.000 claims description 3
- 229940087646 methanolamine Drugs 0.000 claims description 3
- 229910001379 sodium hypophosphite Inorganic materials 0.000 claims description 3
- 239000000203 mixture Substances 0.000 abstract description 8
- 239000011358 absorbing material Substances 0.000 description 17
- 238000009210 therapy by ultrasound Methods 0.000 description 16
- 239000011258 core-shell material Substances 0.000 description 13
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 13
- 239000006228 supernatant Substances 0.000 description 13
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- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 6
- 230000007246 mechanism Effects 0.000 description 6
- NDLPOXTZKUMGOV-UHFFFAOYSA-N oxo(oxoferriooxy)iron hydrate Chemical compound O.O=[Fe]O[Fe]=O NDLPOXTZKUMGOV-UHFFFAOYSA-N 0.000 description 6
- 230000006872 improvement Effects 0.000 description 5
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- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- 229910001289 Manganese-zinc ferrite Inorganic materials 0.000 description 2
- JIYIUPFAJUGHNL-UHFFFAOYSA-N [O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[Mn++].[Mn++].[Mn++].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Zn++].[Zn++] Chemical compound [O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[Mn++].[Mn++].[Mn++].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Zn++].[Zn++] JIYIUPFAJUGHNL-UHFFFAOYSA-N 0.000 description 2
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- 229910000859 α-Fe Inorganic materials 0.000 description 2
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
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Images
Classifications
-
- 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
- H01Q17/004—Devices for absorbing waves radiated from an antenna; Combinations of such devices with active antenna elements or systems using non-directional dissipative particles, e.g. ferrite powders
-
- 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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- Glass Compositions (AREA)
Abstract
The invention provides hollow glass bead/ferroferric oxide/carbon wave-absorbing powder and a preparation method thereof. The preparation method comprises the step of S1, preparing hollow glass beads/ferroferric oxide/silicon dioxide; step S2, adding the prepared PVP modified hollow glass bead/ferroferric oxide/silicon dioxide into an inorganic solvent containing pyrrole under the action of a catalyst, stirring and drying to prepare the hollow glass bead/ferroferric oxide/silicon dioxide/polypyrrole microsphere; step S3, calcining the hollow glass beads/ferroferric oxide/silicon dioxide/polypyrrole microspheres at high temperature in an inert gas atmosphere to obtain hollow glass beads/ferroferric oxide/silicon dioxide/carbon microspheres; and then adding the mixture into an alkali solution for etching, and then stirring and drying to obtain the hollow glass bead/ferroferric oxide/carbon wave-absorbing powder with a gap between a ferroferric oxide layer and a carbon layer.
Description
Technical Field
The invention relates to the field of wave-absorbing materials, in particular to hollow glass bead/ferroferric oxide/carbon wave-absorbing powder and a preparation method thereof.
Background
The hollow glass bead is a hollow, light and uniform spherical particle, and has the characteristics of high and low temperature resistance, corrosion resistance, insulation, heat insulation, stable chemical performance, high strength, no toxicity and the like. Although the light composite wave-absorbing material does not have the wave-absorbing property, if one or more layers of wave-absorbing agents with good chemical stability and strong wave-absorbing capability are coated on the surface of the light hollow glass microsphere, the cost can be reduced, the resources can be effectively utilized, the density of the material can be reduced, and the ideal light composite wave-absorbing material can be obtained.
At present, there are many researches on the application of glass beads in the field of wave absorption:
the existing literature provides a fly ash glass bead/ferrite composite wave-absorbing material, and the fly ash glass bead is coated with a specific kind of ferrite, so that the fly ash glass bead has excellent wave-absorbing performance. The composite wave-absorbing material is light in weight and also has a certain sound absorption effect.
Another prior document provides a surface chemical plating process for hollow glass beads, and the prepared plated metal hollow glass beads have the advantages of complete metal layer, light weight, good conductivity and the like, and can be used as a filler to reduce material density, reduce cost and enhance mechanical properties.
Another prior document provides a method for plating silver on the surface of a hollow glass bead and a silver-plated hollow glass bead thereof, wherein the silver-plated hollow glass bead not only has low infrared emissivity, but also has certain radar wave-absorbing performance. Compared with the pure metal particles, the silver-plated hollow glass microspheres have lower cost. However, the above method has a problem that the loss mechanism of electromagnetic waves is single, and the absorption performance thereof cannot meet the existing demand for a high-performance wave absorber.
In view of the above problems, it is desirable to provide a wave-absorbing material with low density, low cost, good mechanical properties and high wave-absorbing properties.
Disclosure of Invention
The invention mainly aims to provide hollow glass bead/ferroferric oxide/carbon wave-absorbing powder and a preparation method thereof, aiming at solving the problems that the existing wave-absorbing material has a single loss mechanism for electromagnetic waves and cannot meet the requirement of a high-performance wave-absorbing agent.
In order to achieve the purpose, the invention provides a preparation method of hollow glass bead/ferroferric oxide/carbon wave-absorbing powder, which comprises the following steps: step S1, preparing hollow glass beads/ferroferric oxide/silicon dioxide; step S2, adding the hollow glass beads/ferroferric oxide/silicon dioxide into an organic solvent containing polyvinylpyrrolidone, and preparing modified hollow glass beads/ferroferric oxide/silicon dioxide after performing dispersion treatment and drying; under the action of a catalyst, adding the modified hollow glass beads/ferroferric oxide/silicon dioxide into an inorganic solvent containing pyrrole, stirring and drying to prepare hollow glass beads/ferroferric oxide/silicon dioxide/polypyrrole microspheres; step S3, calcining the hollow glass beads/ferroferric oxide/silicon dioxide/polypyrrole microspheres at high temperature in an inert gas atmosphere to obtain hollow glass beads/ferroferric oxide/silicon dioxide/carbon microspheres; adding the hollow glass beads/ferroferric oxide/silicon dioxide/carbon microspheres into an alkaline solution for etching, and then stirring and drying to obtain the hollow glass beads/ferroferric oxide/carbon wave-absorbing powder with the gaps between the ferroferric oxide layer and the carbon layer.
Further, step S2 specifically includes: adding hollow glass beads/ferroferric oxide/silicon dioxide into an organic solvent, and performing ultrasonic dispersion treatment; then adding polyvinylpyrrolidone, and preparing modified hollow glass beads/ferroferric oxide/silicon dioxide after ultrasonic dispersion treatment, filtration and drying; adding the modified hollow glass beads/ferroferric oxide/silicon dioxide into an inorganic solvent, and performing ultrasonic dispersion treatment; and then adding a catalyst, stirring, adding pyrrole, further stirring, filtering and drying to prepare the hollow glass microsphere/ferroferric oxide/silicon dioxide/polypyrrole microsphere.
Further, the organic solvent is ethanol or acetone, the inorganic solvent is deionized water, and the catalyst comprises ferric chloride; in the step of preparing the modified hollow glass beads/ferroferric oxide/silicon dioxide, 1-6 parts by mass of the hollow glass beads/ferroferric oxide/silicon dioxide, 50-400 parts by mass of ethanol or acetone and 3-8 parts by mass of polyvinylpyrrolidone are used; in the step of preparing the hollow glass bead/ferroferric oxide/silicon dioxide/polypyrrole microsphere, 1-6 parts by mass of the modified hollow glass bead/ferroferric oxide/silicon dioxide, 100-400 parts by mass of deionized water, 5-10 parts by mass of ferric chloride and 1-5 parts by mass of pyrrole are used.
Further, step S3 specifically includes: calcining the hollow glass bead/ferroferric oxide/silicon dioxide/polypyrrole microspheres for 2-6 hours under the condition of nitrogen at the temperature of 500-800 ℃ to obtain the hollow glass bead/ferroferric oxide/silicon dioxide/carbon microspheres; and then dispersing the hollow glass beads/ferroferric oxide/silicon dioxide/carbon microspheres into 100-400 parts of 10-30% sodium hydroxide solution for etching, stirring at the rotating speed of 800-1500 r/min for 10-20 hours at the temperature of 40-80 ℃, collecting precipitates by using a magnet, pouring out supernate, washing for 3-6 times by using distilled water, and drying the precipitates for 8-15 hours in a blast oven at the temperature of 40-80 ℃ to obtain the hollow glass beads/ferroferric oxide/carbon wave-absorbing powder.
Further, step S1 specifically includes: substep S11, pretreating the hollow glass beads with an alkali solution; substep S12 converting Fe (CO)5Adding the pretreated hollow glass beads into an alcohol amine solvent, and stirring to obtain a reaction solution; adding an alkali solution and a reducing agent into the reaction solution, stirring, filtering and drying to obtain hollow glass beads/ferroferric oxide with a core/shell structure; step S13, adding the hollow glass beads/ferroferric oxide into the mixed solution for dispersion treatment; and then adding ethyl orthosilicate, stirring, filtering and drying to obtain the hollow glass microsphere/ferroferric oxide/silicon dioxide with the core/shell structure.
Further, the alcohol amine solvent is one or more of methanolamine, ethanolamine and diethanolamine; the alkali solution is one or more of NaOH and KOH; the reducing agent is one or more of hydrazine hydrate and sodium hypophosphite; the mixed solution comprises absolute ethyl alcohol or acetone, water and weak base solution.
Further, the substep S12 hasThe body includes: mixing Fe (CO)5Adding the pretreated hollow glass beads into an alcohol amine solvent, and stirring to obtain a reaction solution; adding an alkali solution into the reaction solution to keep the pH value within 8-10, adding a reducing agent into the reaction solution, and stirring to fully react to obtain a first precipitate; and cleaning the first precipitate by using a first cleaning solution, and drying to obtain the hollow glass bead/ferroferric oxide.
Further, the first cleaning solution is deionized water, the aqueous alkali is a NaOH solution, and the reducing agent is hydrazine hydrate; the pretreated hollow glass beads are 8-50 parts by mass of Fe (CO)55-40 parts by mass of an alcohol amine solvent, 200-600 parts by mass of an alcohol amine solvent; the mass concentration of the NaOH solution is 5-28%, and the mass concentration of the hydrazine hydrate is 10-50 parts.
Further, the sub-step S13 specifically includes: adding the hollow glass beads/ferroferric oxide into a mixed solution of a solvent, water and weak base, and performing ultrasonic dispersion treatment; then adding tetraethoxysilane, and stirring in a water bath to react to obtain a second precipitate; and cleaning the second precipitate by using a second cleaning solution, and drying to obtain the hollow glass bead/ferroferric oxide/silicon dioxide.
Further, the solvent comprises absolute ethyl alcohol, and the weak base comprises ammonia water; 2-10 parts of hollow glass beads/ferroferric oxide, 800-1200 parts of absolute ethyl alcohol, 200-500 parts of water, 20-100 parts of ammonia water and 1-6 parts of ethyl orthosilicate.
The hollow glass bead/ferroferric oxide/carbon wave-absorbing powder comprises a hollow glass bead layer serving as a hollow inner core layer, and a ferroferric oxide layer and a carbon layer which are sequentially coated on the outer surface of the hollow inner core layer from inside to outside, wherein a gap is formed between the ferroferric oxide layer and the carbon layer.
By applying the technical scheme of the invention, the hollow glass bead/ferroferric oxide/carbon wave-absorbing powder has a unique double-shell-double hollow structure, so that the density of the wave-absorbing powder can be greatly reduced, the multiple reflection loss of electromagnetic waves in the wave-absorbing powder is greatly realized, the propagation path of the electromagnetic waves is increased, the loss mechanism of the wave-absorbing powder is enriched, the spatial polarization effect of the wave-absorbing powder can be improved, and the dielectric constant and the magnetic conductivity of the wave-absorbing powder are obviously improved. Meanwhile, the wave-absorbing powder has the excellent characteristics of corrosion resistance and oxidation resistance, improvement of the compatibility and the dispersibility with a matrix, improvement of the interface bonding force and the like, and can meet the requirements of different application scenes. In addition, the hollow glass beads are used as the hollow inner core layer, and the preparation cost of the hollow glass bead layer, the ferroferric oxide layer and the carbon layer is lower. Therefore, the hollow glass bead/ferroferric oxide/carbon wave-absorbing powder with the double-shell-double hollow structure belongs to a wave-absorbing agent with excellent electromagnetic performance and good physical and chemical performance advantages, and has the advantages of low cost, oxidation resistance, corrosion resistance and the like.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:
fig. 1 shows a process flow diagram of a preparation method of hollow glass beads/ferroferric oxide/carbon wave-absorbing powder with a double-shell-double hollow structure provided in embodiment 1 of the invention; and
fig. 2 shows a schematic structural diagram of a hollow glass bead/ferroferric oxide/carbon wave-absorbing powder with a double-shell-double-hollow structure provided in example 1.
Wherein the figures include the following reference numerals:
1. hollow glass beads; 2. fe3O4A layer; 3. SiO 22A layer; 4. PVP; 5. a polypyrrole layer; 6. a carbon layer.
Detailed Description
It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict. The present invention will be described in detail with reference to examples.
As described in the background art, the existing wave-absorbing material has a single loss mechanism for electromagnetic waves and cannot meet the requirement of a high-performance wave-absorbing agent. In order to solve the technical problems, the invention provides a hollow glass bead/ferroferric oxide/carbon wave-absorbing powder with a double-hollow-double-core shell structure, which comprises a hollow glass bead layer serving as a hollow inner core layer, and a ferroferric oxide layer and a carbon layer which are sequentially coated on the outer surface of the hollow inner core layer from inside to outside, wherein a gap is formed between the ferroferric oxide layer and the carbon layer.
The hollow glass bead/ferroferric oxide/carbon wave-absorbing powder has a unique double-shell-double hollow structure, so that the density of the wave-absorbing powder can be greatly reduced, the multiple reflection loss of electromagnetic waves in the wave-absorbing powder is greatly realized, the propagation path of the electromagnetic waves is increased, the loss mechanism of the wave-absorbing powder is enriched, the spatial polarization effect of the wave-absorbing powder can be improved, and the dielectric constant and the magnetic conductivity of the wave-absorbing powder are obviously improved. Meanwhile, the wave-absorbing powder has the excellent characteristics of corrosion resistance, oxidation resistance, improvement on compatibility and dispersibility with a matrix, improvement on interface binding force and the like, and can meet the requirements of different application scenes. In addition, the existing hollow materials which can be used as the hollow inner core layer have more optional types, and the preparation cost of the hollow materials, the ferric oxide layer and the carbon layer is lower. Therefore, the hollow glass bead/ferroferric oxide/carbon wave-absorbing powder with the double-shell-double hollow structure belongs to a wave-absorbing agent with excellent electromagnetic performance and good physical and chemical performance advantages, and has the advantages of low cost, oxidation resistance, corrosion resistance and the like.
In the hollow glass bead/ferroferric oxide/carbon wave-absorbing powder, the hollow glass beads are used as the hollow inner core layer, so that the density and the cost of the wave-absorbing material can be further reduced. The particle size range of the hollow glass beads means the particle size of the existing commercially available product.
The invention also provides a preparation method of the hollow glass bead/ferroferric oxide/carbon wave-absorbing powder with the double-hollow-double-shell structure, which comprises the following steps: step S1, preparing hollow glass beads/ferroferric oxide/silicon dioxide; step S2, adding the hollow glass beads/ferroferric oxide/silicon dioxide into an organic solvent containing polyvinylpyrrolidone, and performing dispersion treatment and drying to prepare modified hollow glass beads/ferroferric oxide/silicon dioxide; under the action of a catalyst, adding the modified hollow glass microspheres/ferroferric oxide/silicon dioxide into an inorganic solvent containing pyrrole, stirring and drying to prepare hollow glass microspheres/ferroferric oxide/silicon dioxide/polypyrrole microspheres; step S3, calcining the hollow glass beads/ferroferric oxide/silicon dioxide/polypyrrole microspheres at high temperature in an inert gas atmosphere to obtain hollow glass beads/ferroferric oxide/silicon dioxide/carbon microspheres; adding the hollow glass beads/ferroferric oxide/silicon dioxide/carbon microspheres into an alkaline solution for etching, and then stirring and drying to obtain the hollow glass beads/ferroferric oxide/carbon wave-absorbing powder with the gaps between the ferroferric oxide layer and the carbon layer.
The process method and the equipment are simple, have no pollution, are easy to control the structure and the performance, and are suitable for mass production. Meanwhile, the prepared hollow glass bead/ferroferric oxide/carbon wave-absorbing powder has a special double-hollow-double-core shell structure, has the advantages of excellent electromagnetic performance and good physical and chemical properties, and also has the advantages of low cost, oxidation resistance, corrosion resistance and the like.
Forming a carbon layer outside the ferric oxide layer is beneficial to improving the oxidation resistance and corrosion resistance of the wave-absorbing material, and in order to further improve the uniformity of the carbon layer, preferably, the step S2 specifically includes: adding hollow glass beads/ferroferric oxide/silicon dioxide into an organic solvent, and performing ultrasonic dispersion treatment; then adding polyvinylpyrrolidone, and preparing modified hollow glass beads/ferroferric oxide/silicon dioxide after ultrasonic dispersion treatment, filtration and drying; adding the modified hollow glass beads/ferroferric oxide/silicon dioxide into an inorganic solvent, and performing ultrasonic dispersion treatment; and then adding a catalyst, stirring, adding pyrrole, further stirring, filtering and drying to prepare the hollow glass microsphere/ferroferric oxide/silicon dioxide/polypyrrole (PPy) microsphere.
In order to remove the solvent used in the preparation process, a solvent with a low boiling point is required. Considering the solvent property of the solvent to the raw material and the safety and cost of the preparation process, preferably, the organic solvent is ethanol or acetone, and the inorganic solvent is deionized water.
In a preferred embodiment, the catalyst comprises ferric chloride. Compared with other catalysts, the pyrrole has higher catalytic activity in the presence of the catalysts, and the catalyst is easier to remove after the reaction is finished.
In a preferred embodiment, in the step of preparing the modified hollow glass beads/ferroferric oxide/silicon dioxide, 1 to 6 parts by mass of the hollow glass beads/ferroferric oxide/silicon dioxide, 50 to 400 parts by mass of ethanol or acetone, and 3 to 8 parts by mass of polyvinylpyrrolidone are used. The weight ratio of the hollow glass beads/ferroferric oxide/silicon dioxide, the organic solvent (ethanol or acetone) and the polyvinylpyrrolidone is not limited to the range, and the limitation of the weight ratio to the range is favorable for further improving the coating uniformity, the structural stability and the void ratio of a subsequently formed polypyrrole layer on the surface of the silicon dioxide layer, so that the corrosion resistance, the oxidation resistance and the wave loss of the finally formed hollow glass beads/ferroferric oxide/carbon wave-absorbing powder are further improved.
In a preferred embodiment, in the step of preparing the hollow glass beads/ferroferric oxide/silicon dioxide/polypyrrole microspheres, 1 to 6 parts by mass of the modified hollow glass beads/ferroferric oxide/silicon dioxide, 100 to 400 parts by mass of deionized water, 5 to 10 parts by mass of ferric chloride, and 1 to 5 parts by mass of pyrrole are used. The weight ratio of the modified hollow glass beads/ferroferric oxide/silicon dioxide, the deionized water, the ferric chloride and the pyrrole includes but is not limited to the range, and the limitation of the weight ratio in the range is favorable for further improving the coating uniformity and the coating amount of the polypyrrole layer, so that the wave loss and the mechanical property of the hollow glass beads/ferroferric oxide/carbon wave-absorbing powder are favorably improved.
In an embodiment of the present invention, step S3 specifically includes: calcining the hollow glass beads/ferroferric oxide/silicon dioxide/polypyrrole microspheres for 2-6 hours at the temperature of 500-800 ℃ under the condition of nitrogen to obtain the hollow glass beads/ferroferric oxide/silicon dioxide/carbon microspheres; and then dispersing the hollow glass beads/ferroferric oxide/silicon dioxide/carbon microspheres into 100-400 parts of 10-30% sodium hydroxide solution for etching, stirring at the rotating speed of 800-1500 r/min for 10-20 hours at the temperature of 40-80 ℃, collecting precipitates by using a magnet, pouring out supernate, washing for 3-6 times by using distilled water, and drying the precipitates for 8-15 hours in a blast oven at the temperature of 40-80 ℃ to obtain the hollow glass beads/ferroferric oxide/carbon wave-absorbing powder. The calcination temperature is limited in the range, so that the void ratio of the wave-absorbing material is further improved, and the density and the wave-convection loss of the wave-absorbing material are further reduced. Limiting the concentration of sodium hydroxide, the temperature, the rotating speed and the time in the etching process within the ranges is beneficial to further improving the porosity between the ferroferric oxide layer and the carbon layer, thereby being beneficial to further improving the wave loss of the hollow glass bead/ferroferric oxide/carbon wave-absorbing powder. Limiting the temperature and time of the drying process in the above range is beneficial to improving the drying efficiency and shortening the preparation period.
In an embodiment of the present invention, step S1 specifically includes: a substep S11 of pretreating the hollow glass microspheres with an alkali solution; substep S12 converting Fe (CO)5Adding the pretreated hollow glass beads into an alcohol amine solvent, and stirring to obtain a reaction solution; and then adding an alkali solution and a reducing agent into the reaction solution, stirring, filtering and drying to obtain the hollow glass bead/ferroferric oxide with the core/shell structure. Wherein, the core/shell structure sheet alloy powder/manganese zinc ferrite means that ferroferric oxide generated by reaction is coated on the outer surface of the hollow glass micro-beads; step S13, adding the hollow glass beads/ferroferric oxide into the mixed solution for dispersion treatment; then adding ethyl orthosilicate, stirring, filtering and drying to obtain the hollow glass microsphere/ferroferric oxide with the core/shell structureSilicon dioxide. The core/shell structure sheet alloy powder/manganese-zinc ferrite/silicon dioxide wave-absorbing powder is formed by coating ferroferric oxide on the outer surface of hollow glass microspheres, and the silicon dioxide generated by reaction is coated on the outer surface of the ferroferric oxide.
In one non-limiting example, the alcohol amine solvent is one or more of methanolamine, ethanolamine, and diethanolamine.
The alcohol amine solvents are alkalescent and are used as the solvents to further improve Fe (CO)5The reaction rate is high, so that the conversion rate of the ferroferric hydroxide is further improved, and the wave absorbing performance of the wave absorbing material is further improved. The amount of the alcohol amine solution is not particularly limited and may be adjusted as desired.
In the above substep S11, the alkali solution may be used in a kind commonly used in the art, such as NaOH and/or KOH.
In one embodiment of the invention, the reducing agent is hydrazine hydrate and/or sodium hypophosphite. Compared with other reducing agents, the reducing agent has weaker reducing performance, so that the reducing agent is adopted to participate in reduction reaction, and the ferric trioxide can be converted into the ferroferric oxide.
In one embodiment of the present invention, the mixed solution includes absolute ethanol, acetone, water, and a weak base solution. In a preferred embodiment, the weak base solution is ammonia.
In an embodiment of the present invention, the sub-step S12 specifically includes: mixing Fe (CO)5Adding the pretreated hollow glass beads into an alcohol amine solvent, and stirring to obtain a reaction solution; adding an alkali solution into the reaction solution to keep the pH value within 8-10, adding a reducing agent into the reaction solution, and stirring to fully react to obtain a first precipitate; and cleaning the first precipitate by using a first cleaning solution, and drying to obtain the hollow glass bead/ferroferric oxide.
In the above coating process, Fe (CO)5Unstable and forms ferric oxide after contacting with solvent, and the reaction of the ferric oxide with reductant can reduce partial ferric oxide into ferric oxideAnd (4) oxidizing ferrous iron to obtain a ferroferric oxide coating layer. The ferroferric oxide layer formed on the surface of the hollow material by adopting the preparation method is favorable for improving the uniformity of the ferroferric oxide coating layer, thereby being favorable for further improving the performance stability and uniformity of the wave-absorbing material.
In a preferred embodiment, the first cleaning solution is deionized water, the alkaline solution is a NaOH solution, and the reducing agent is hydrazine hydrate; the pretreated hollow glass beads are 8-50 parts by mass of Fe (CO)55-40 parts by mass of an alcohol amine solvent, 200-600 parts by mass of an alcohol amine solvent; the mass concentration of the NaOH solution is 5-28%, and the mass concentration of the hydrazine hydrate is 10-50 parts. The pH value and the hollow material of the step of coating ferroferric oxide, Fe (CO)5And the weight ratio of the reducing agent is limited in the range, which is favorable for further improving the conversion rate of the ferric oxide, thereby being favorable for further improving the wave-absorbing performance of the wave-absorbing material.
In a preferred embodiment, the sub-step S13 specifically includes: adding the hollow glass beads/ferroferric oxide into a mixed solution of a solvent, water and weak base, and performing ultrasonic dispersion treatment; then adding tetraethoxysilane, and stirring in a water bath to react to obtain a second precipitate; and cleaning the second precipitate by using a second cleaning solution, and drying to obtain the hollow glass bead/ferroferric oxide/silicon dioxide.
In order to further improve the coating rate and the coating amount of the silicon dioxide layer and further improve the wave loss rate of the subsequently prepared hollow glass bead/ferroferric oxide/carbon wave-absorbing powder, preferably, the solvent comprises absolute ethyl alcohol, and the weak base comprises ammonia water; 2-10 parts of hollow glass beads/ferroferric oxide, 800-1200 parts of absolute ethyl alcohol, 200-500 parts of water, 20-100 parts of ammonia water and 1-6 parts of ethyl orthosilicate.
The invention also provides a wave absorbing device which comprises a wave absorbing material, wherein the wave absorbing material comprises the hollow glass bead/ferroferric oxide/carbon wave absorbing powder with the double-hollow-double-core shell structure provided by the invention, or the hollow glass bead/ferroferric oxide/carbon wave absorbing powder with the double-hollow-double-core shell structure prepared by the preparation method provided by the invention.
The hollow glass bead/ferroferric oxide/carbon wave-absorbing powder with the double-hollow-double-core shell structure has the advantages of excellent electromagnetic property, good physical and chemical properties, low cost, oxidation resistance, corrosion resistance and the like. Therefore, the wave absorbing device prepared by the hollow glass bead/ferroferric oxide/carbon wave absorbing powder with the double-shell-double hollow structure can greatly improve the wave absorbing performance and the wave absorbing stability of the wave absorbing device.
The present invention is described in further detail below with reference to specific examples, which are not to be construed as limiting the scope of the invention as claimed.
Comparative example 1
A preparation method of hollow glass beads/ferroferric oxide comprises the following steps:
1. preparation of hollow glass bead/ferroferric oxide particle
1.1 pretreatment of hollow glass microspheres
Weighing 60 parts of hollow glass beads, placing the hollow glass beads in a NaOH solution with the concentration of 40%, carrying out ultrasonic treatment for 400min, then carrying out washing and cleaning for 5 times, placing the washed hollow glass beads in a 120 ℃ blast oven for drying treatment for 12 hours, and reserving for later use, thus finishing the pretreatment of the hollow glass beads.
1.2 preparation of hollow glass beads/ferroferric oxide
Respectively mixing 30 parts of pretreated hollow glass beads, 25 parts of oily liquid Fe (CO)5Adding the mixture into 400 parts of alcohol amine solvent to be used as reaction liquid, and uniformly stirring at the speed of 400 r/min; sodium hydroxide solution with the concentration of 15% is prepared to be used as pH adjusting solution of the reaction solution. Dropwise adding a pH adjusting solution into the reaction solution, controlling the pH within 9, then adding 30 parts of hydrazine hydrate (85%) into the reaction solution, continuously stirring for 3 hours in a 14 ℃ oil bath kettle at the rotating speed of 1000r/min, collecting black precipitate by using a magnet after the reaction is finished, pouring out supernatant, washing paint for 5 times by using deionized water and absolute ethyl alcohol respectively, after the washing is finished, putting the precipitate into a 60 ℃ blast oven, drying for 12 hours, and finishing the micro-drying treatment of the hollow glassPreparing beads/ferroferric oxide.
Example 1
A method for preparing hollow glass bead/ferroferric oxide/carbon wave-absorbing powder with a unique double-hollow-double-core shell structure comprises the following steps of (1) preparing a process flow shown in figure, and (2) preparing a wave-absorbing agent shown in figure 2 (wherein 1 represents hollow glass bead, and 2 represents Fe3O4Layer, 3 represents SiO2Layer, 4 PVP, 5 polypyrrole layer, 6 carbon layer) comprising the steps of:
1. preparation of hollow glass bead/ferroferric oxide particle
1.1 pretreatment of hollow glass microspheres
Weighing 60 parts of hollow glass beads, placing the hollow glass beads in a NaOH solution with the concentration of 40%, carrying out ultrasonic treatment for 400min, then carrying out washing and cleaning for 5 times, placing the washed hollow glass beads in a 120 ℃ blast oven for drying treatment for 12 hours, and reserving for later use, thus finishing the pretreatment of the hollow glass beads.
1.2 hollow glass Microbeads/Fe3O4Preparation of
Respectively mixing 30 parts of pretreated hollow glass beads, 25 parts of oily liquid Fe (CO)5Adding the mixture into 400 parts of alcohol amine solvent to be used as reaction liquid, and uniformly stirring at the speed of 400 r/min; sodium hydroxide solution with the concentration of 15% is prepared to be used as pH adjusting solution of the reaction solution. Dropwise adding a pH adjusting solution into the reaction solution, controlling the pH within 9 range, then adding 30 parts of hydrazine hydrate (85%) into the reaction solution, continuously stirring for 3 hours in a 14 ℃ oil bath kettle at the rotating speed of 1000r/min, collecting black precipitate by using a magnet after the reaction is finished, pouring out supernatant, washing paint for 5 times by using deionized water and absolute ethyl alcohol respectively, and after the washing is finished, putting the precipitate into a 60 ℃ blast oven for drying treatment for 12 hours to finish the preparation of the hollow glass bead/ferroferric oxide.
2. Preparation of hollow glass bead/ferroferric oxide/carbon wave-absorbing powder with double hollow bodies and double core shells
2.1 preparation of hollow glass beads/ferroferric oxide/silicon dioxide
10 parts of prepared hollow glass microsphere/Fe304Adding the mixture into a mixed solution of 1200 parts of absolute ethyl alcohol, 500 parts of water and 100 parts of ammonia water with the mass concentration of 28 wt%, carrying out ultrasonic treatment for 30min to ensure that the pretreated hollow glass beads/ferroferric oxide particles can be uniformly dispersed into the solution, then dripping 1 part of tetraethoxysilane into the solution, and continuously stirring for 3 hours in a water bath kettle at the temperature of 40 ℃ at the rotating speed of 400 r/min. And after the reaction is finished, collecting the precipitate by using a magnet, pouring out the supernatant, washing the supernatant by using ethanol for 5 times, and drying the precipitate in a 60-DEG C forced air oven for 12 hours to finish the preparation of the hollow glass bead/ferroferric oxide/silicon dioxide.
2.2 modification of hollow glass Microbeads/ferroferric oxide/silica
Dispersing 6 parts of hollow glass beads/ferroferric oxide/silicon dioxide into 400 parts of ethanol solution, performing ultrasonic treatment for 20min, adding 3 parts of PVP (polyvinyl pyrrolidone), continuously performing ultrasonic treatment for 50min, washing with distilled water for 5 times for later use, and then putting the washed precipitate into a 60 ℃ air-blowing oven for drying treatment for 12 hours to finish the modification of the hollow glass beads/ferroferric oxide/silicon dioxide.
2.2 preparation of hollow glass bead/ferroferric oxide/carbon wave-absorbing powder
Dispersing 6 parts of PVP modified hollow glass microsphere/ferroferric oxide/silicon dioxide into 400 parts of deionized water, performing ultrasonic treatment for 20min, adding 5 parts of ferric chloride, stirring for 30min, adding 1 part of pyrrole, reacting for 6 hours at a rotating speed of 600r/min under the stirring of water bath at 40 ℃, collecting a precipitate with a magnet after the reaction is finished, pouring out a supernatant, cleaning with distilled water and ethanol for 5 times respectively, and drying the precipitate in a blast oven at 60 ℃ for 12 hours to obtain the hollow glass microsphere/ferroferric oxide/silicon dioxide/PPy (polypyrrole) microsphere.
Calcining the obtained hollow glass bead/ferroferric oxide/silicon dioxide/PPy (polypyrrole) microsphere for 2 hours at 500 ℃ in a tubular furnace under the condition of nitrogen, dispersing the obtained hollow glass bead/ferroferric oxide/silicon dioxide/carbon microsphere into 100 parts of 15% sodium hydroxide solution for etching, stirring for 10 hours at the rotating speed of 1000r/min under the condition of 60 ℃, collecting precipitates by using a magnet, pouring out supernate, washing for 5 times by using distilled water, and drying the precipitates in a blast oven at 60 ℃ for 12 hours to obtain the hollow glass bead/ferroferric oxide/carbon wave-absorbing powder with the double-hollow-double-core shell structure.
Example 2
A preparation method of hollow glass bead/ferroferric oxide/carbon wave-absorbing powder with a unique double-hollow-double-core shell structure comprises the following steps:
1. preparation of hollow glass bead/ferroferric oxide particle
1.1 pretreatment of hollow glass microspheres
Same as in example 1.
1.2 preparation of hollow glass beads/ferroferric oxide
Same as in example 1.
2. Preparation of hollow glass bead/ferroferric oxide/carbon wave-absorbing powder with double hollow-double shells
2.1 preparation of hollow glass beads/ferroferric oxide/silicon dioxide
Adding 6 parts of the prepared hollow glass bead/ferroferric oxide into a mixed solution of 1000 parts of absolute ethyl alcohol, 400 parts of water and 600 parts of ammonia water with the mass concentration of 28 wt%, carrying out ultrasonic treatment for 40 minutes to enable the pretreated hollow glass bead/ferroferric oxide particles to be uniformly dispersed into the solution, then dripping 3 parts of tetraethoxysilane into the solution, and continuously stirring for 4 hours in a 60 ℃ water bath at the rotating speed of 600 r/min. And after the reaction is finished, collecting the precipitate by using a magnet, pouring out the supernatant, washing the supernatant by using ethanol for 5 times, and drying the precipitate in a 60-DEG C forced air oven for 12 hours to finish the preparation of the hollow glass bead/ferroferric oxide/silicon dioxide.
2.2 modification of hollow glass Microbeads/ferroferric oxide/silica
Dispersing 3 parts of hollow glass beads/ferroferric oxide/silicon dioxide into 200 parts of ethanol solution, performing ultrasonic treatment for 30min, adding 6 parts of PVP (polyvinyl pyrrolidone), continuously performing ultrasonic treatment for 50min, washing with distilled water for 5 times for later use, and then putting the washed precipitate into a 60 ℃ air-blowing oven for drying treatment for 12 hours to finish the modification of the hollow glass beads/ferroferric oxide/silicon dioxide.
2.3 preparation of hollow glass bead/ferroferric oxide/carbon wave-absorbing powder
Dispersing 4 parts of hollow glass microsphere/ferroferric oxide/silicon dioxide modified by PVP into 200 parts of deionized water, performing ultrasonic treatment for 20min, adding 80 parts of ferric chloride, stirring for 60min, adding 3 parts of pyrrole, reacting for 10 hours at a rotating speed of 600r/min under the stirring of water bath at 40 ℃, collecting a precipitate by using a magnet after the reaction is finished, pouring out a supernatant, respectively cleaning for 5 times by using distilled water and ethanol, and drying the precipitate in a blast oven at 60 ℃ for 12 hours to obtain the hollow glass microsphere/ferroferric oxide/silicon dioxide/PPy (polypyrrole) microsphere.
Calcining the obtained hollow glass bead/ferroferric oxide/silicon dioxide/PPy (polypyrrole) microsphere for 4 hours at 600 ℃ in a tubular furnace under the condition of nitrogen, dispersing the obtained hollow glass bead/ferroferric oxide/silicon dioxide/carbon microsphere into 300 parts of 20% sodium hydroxide solution for etching, stirring for 15 hours at the rotating speed of 1200r/min under the condition of 60 ℃, collecting precipitates by using a magnet, pouring out supernate, washing for 5 times by using distilled water, and drying the precipitates in a blast oven at 60 ℃ for 12 hours to obtain the hollow glass bead/ferroferric oxide/carbon wave-absorbing powder with the double-hollow-double-core shell structure.
Example 3
A preparation method of hollow glass bead/ferroferric oxide/carbon wave-absorbing powder with a unique double-hollow-double-core shell structure comprises the following steps:
1. preparation of hollow glass bead/ferroferric oxide particle
1.1 pretreatment of hollow glass microspheres
Same as in example 1.
1.2 hollow glass Microbeads/Fe3O4Preparation of
Same as in example 1.
2. Preparation of hollow glass bead/ferroferric oxide/carbon wave-absorbing powder with double-hollow-double-nucleocapsid structure
2.1 preparation of hollow glass beads/ferroferric oxide/silicon dioxide
Adding 2 parts of prepared hollow glass beads/ferroferric oxide into a mixed solution of 800 parts of absolute ethyl alcohol, 200 parts of water and 40 parts of ammonia water with the mass concentration of 28 wt%, carrying out ultrasonic treatment for 50 minutes to ensure that pretreated hollow glass beads/ferroferric oxide particles can be uniformly dispersed into the solution, then dripping 6 parts of tetraethoxysilane into the solution, and continuously stirring for 6 hours in a water bath kettle at the temperature of 80 ℃ at the rotating speed of 1000 r/min. And after the reaction is finished, collecting the precipitate by using a magnet, pouring out the supernatant, washing the supernatant by using ethanol for 5 times, and drying the precipitate in a 60-DEG C forced air oven for 12 hours to finish the preparation of the hollow glass bead/ferroferric oxide/silicon dioxide.
2.2 modification of hollow glass Microbeads/ferroferric oxide/silicon dioxide
Dispersing 1 part of hollow glass bead/ferroferric oxide/silicon dioxide into 50 parts of ethanol solution, performing ultrasonic treatment for 40min, then adding 8 parts of PVP (polyvinyl pyrrolidone), continuously performing ultrasonic treatment for 60min, washing with distilled water for 5 times for later use, then placing the washed precipitate into a 60 ℃ air-blast oven for drying treatment for 12 hours, and finishing the modification of the hollow glass bead/ferroferric oxide/silicon dioxide.
2.3 preparation of hollow glass bead/ferroferric oxide/carbon wave-absorbing powder
Dispersing 1 part of hollow glass microsphere/ferroferric oxide/silicon dioxide modified by PVP into 100 parts of deionized water, performing ultrasonic treatment for 50min, adding 10 parts of ferric chloride, stirring for 80min, adding 5 parts of pyrrole, reacting for 12 hours at the rotating speed of 800r/min under the stirring of water bath at 50 ℃, collecting a precipitate by using a magnet after the reaction is finished, pouring out a supernatant, respectively cleaning for 5 times by using distilled water and ethanol, and drying the precipitate in a blast oven at 60 ℃ for 12 hours to obtain the hollow glass microsphere/ferroferric oxide/silicon dioxide/PPy (polypyrrole) microsphere.
Calcining the obtained hollow glass microspheres/ferroferric oxide/silicon dioxide/PPy (polypyrrole) microspheres for 6 hours at 800 ℃ under the condition of nitrogen in a tubular furnace, dispersing the obtained hollow glass microspheres/ferroferric oxide/silicon dioxide/carbon microspheres into 400 parts of 20% sodium hydroxide solution for etching, stirring for 20 hours at the rotating speed of 1500r/min under the condition of 60 ℃, collecting precipitates by using a magnet, pouring out supernate, washing for 5 times by using distilled water, and drying the precipitates in a blast oven at the temperature of 60 ℃ for 12 hours to obtain the hollow glass microspheres/ferroferric oxide/carbon wave-absorbing powder with the double-hollow-double-core shell structure.
Example 4
A preparation method of hollow glass bead/ferroferric oxide/carbon wave-absorbing powder with a unique double-hollow-double-core shell structure comprises the following steps:
1. preparation of hollow glass bead/ferroferric oxide particle
1.1 pretreatment of hollow glass microspheres
Weighing 100 parts of hollow glass beads, placing the hollow glass beads into a NaOH solution with the concentration of 40%, carrying out ultrasonic treatment for 80min, then carrying out washing and cleaning for 5 times, placing the washed hollow glass beads into a 120 ℃ blast oven, drying for 12 hours, and reserving for later use, thus finishing the pretreatment of the hollow glass beads.
1.2 preparation of hollow glass beads/ferroferric oxide
Respectively mixing 50 parts of pretreated hollow glass microspheres and 5 parts of oily liquid Fe (CO)5Adding the mixture into 200 parts of alcohol amine solvent to be used as reaction liquid, and uniformly stirring at the speed of 200 r/min; preparing a sodium hydroxide solution with the concentration of 5% as a pH adjusting solution of the reaction solution. Dropwise adding a pH adjusting solution into the reaction solution, controlling the pH within 8, then adding 10 parts of hydrazine hydrate (85%) into the reaction solution, continuously stirring for 2 hours in an oil bath kettle at 120 ℃ at the rotating speed of 800r/min, collecting black precipitate by using a magnet after the reaction is finished, pouring out supernatant, washing paint for 5 times by using deionized water and absolute ethyl alcohol respectively, and after the washing is finished, putting the precipitate into a 60 ℃ blast oven for drying treatment for 12 hours to finish the preparation of the hollow glass bead/ferroferric oxide.
2. Preparation of hollow glass bead/ferroferric oxide/carbon wave-absorbing powder with double-hollow-double-nucleocapsid structure
2.1 preparation of hollow glass beads/ferroferric oxide/silicon dioxide
The same as in example 2.
2.2 modification of hollow glass Microbeads/ferroferric oxide/silica
The same as in example 2.
2.3 preparation of hollow glass bead/ferroferric oxide/carbon wave-absorbing powder
The same as in example 2.
Example 5
A preparation method of hollow glass bead/ferroferric oxide/carbon wave-absorbing powder with a unique double-hollow-double-core shell structure comprises the following steps:
1. preparation of hollow glass bead/ferroferric oxide particle
1.1 pretreatment of hollow glass microspheres
Weighing 40 parts of hollow glass beads, placing the hollow glass beads in a NaOH solution with the concentration of 50%, carrying out ultrasonic treatment for 80min, then carrying out water washing and cleaning for 5 times, placing the cleaned hollow glass beads in a 120 ℃ blast oven for drying treatment for 12 hours, and reserving for later use, thus finishing the pretreatment of the hollow glass beads.
1.2 preparation of hollow glass beads/ferroferric oxide
Respectively mixing 8 parts of pretreated hollow glass beads and 40 parts of oily liquid Fe (CO)5Adding the mixture into 600 parts of alcohol amine solvent to be used as reaction liquid, and uniformly stirring at the speed of 500 r/min; sodium hydroxide solution with the concentration of 20% is prepared to be used as pH adjusting solution of the reaction solution. Dropwise adding a pH adjusting solution into the reaction solution, controlling the pH value within 10, then adding 50 parts of hydrazine hydrate (85%) into the reaction solution, continuously stirring for 4 hours in a 160 ℃ oil bath kettle at the rotating speed of 1500r/min, collecting a black precipitate by using a magnet after the reaction is finished, pouring out a supernatant, washing paint for 5 times by using deionized water and absolute ethyl alcohol respectively, and after the washing is finished, putting the precipitate into a 60 ℃ blast oven for drying treatment for 12 hours to finish the preparation of the hollow glass microsphere/ferroferric oxide.
2. Preparation of hollow glass bead/ferroferric oxide/carbon wave-absorbing powder with double-hollow-double-nucleocapsid structure
2.1 preparation of hollow glass beads/ferroferric oxide/silicon dioxide
The same as in example 2.
2.2 modification of hollow glass Microbeads/ferroferric oxide/silica
The same as in example 2.
2.3 preparation of hollow glass bead/ferroferric oxide/carbon wave-absorbing powder
The same as in example 2.
Respectively and uniformly mixing the original hollow glass beads, the hollow glass beads/ferroferric oxide/carbon wave-absorbing powder prepared in the examples 1 to 5 and the comparative example 1 with paraffin, preparing 80% of coaxial samples and testing. The method mainly comprises the following steps: firstly, mixing hollow glass beads/ferroferric oxide/carbon wave-absorbing powder with paraffin according to the ratio of 8:2, and heating the mixture in a high-temperature oven at 65 ℃ for 10 min; then quickly taking out, mixing and stirring uniformly to prepare a viscous solid; filling the viscous solid into a coaxial ring mold (the outer diameter of the mold is 7mm, the inner diameter of the mold is 3.04mm), respectively preparing samples with the thickness of 1-2 mm, and respectively measuring the complex dielectric constant and the complex permeability by using a network vector analyzer; and then calculating a curve of the reflection loss of the test sample along with the change of frequency when the thickness of the test sample is 2.5mm by matlab simulation according to an electromagnetic field transmission line theory.
The tap density of the original hollow glass beads and the hollow glass beads/ferroferric oxide/carbon wave-absorbing powder prepared in the examples 1 to 5 and the comparative example 1 was measured by a tap density meter. The original hollow glass beads and the hollow glass beads/ferroferric oxide/carbon wave-absorbing powder prepared in the examples 1 to 5 and the comparative example 1 are respectively added into 25 percent of dilute hydrochloric acid, and the time for generating bubbles in the solution or the time for changing the color of the solution is observed. The test results are shown in Table 1.
TABLE 1
By reaction with Fe3O4Particle comparison, powders prepared in examples 1-5 and comparative example 1 were tested to find: examples 1-5 and comparative example 1 powder density vs. particulate Fe3O4Has great reductionThe corrosion resistance is obviously improved; in the embodiments 2-5, after the double-shell-double hollow is formed, the relative ratio of the electromagnetic parameters, the absorption bandwidth and the absorption intensity of the powder 1 is greatly improved, compared with the powder in the embodiment 1, because the double-shell-double hollow structure greatly increases the multiple reflection loss mechanism, the dielectric constant and the magnetic conductivity are improved, and the wave-absorbing powder prepared in the embodiments 1-5 is accompanied by Fe3O4The dielectric constant and the magnetic permeability tend to increase with the increase of the thickness of the coating layer, and the dielectric constant tends to increase and the magnetic permeability tends to decrease with the increase of the thickness of the coating layer of the carbon material; in order to obtain excellent electromagnetic absorption performance, both loss and impedance matching of the material are considered. The material loss and impedance matching of example 2 were found to be optimal under formulation tuning, with the best bandwidth and absorption strength.
It is noted that the terms first, second and the like in the description and in the claims of the present invention are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in sequences other than those described or illustrated herein.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (11)
1. A preparation method of hollow glass bead/ferroferric oxide/carbon wave-absorbing powder is characterized by comprising the following steps:
step S1, preparing hollow glass beads/ferroferric oxide/silicon dioxide;
step S2, adding the hollow glass beads/ferroferric oxide/silicon dioxide into an organic solvent containing polyvinylpyrrolidone, and preparing modified hollow glass beads/ferroferric oxide/silicon dioxide after performing dispersion treatment and drying; under the action of a catalyst, adding the modified hollow glass bead/ferroferric oxide/silicon dioxide into an inorganic solvent containing pyrrole, stirring and drying to prepare a hollow glass bead/ferroferric oxide/silicon dioxide/polypyrrole microsphere;
step S3, calcining the hollow glass beads/ferroferric oxide/silicon dioxide/polypyrrole microspheres at high temperature in an inert gas atmosphere to obtain hollow glass beads/ferroferric oxide/silicon dioxide/carbon microspheres; and adding the hollow glass bead/ferroferric oxide/silicon dioxide/carbon microsphere into an alkaline solution for etching, and then stirring and drying to obtain the hollow glass bead/ferroferric oxide/carbon wave-absorbing powder with a gap between a ferroferric oxide layer and a carbon layer.
2. The preparation method of the hollow glass bead/ferroferric oxide/carbon wave-absorbing powder according to claim 1, which is characterized by comprising the following steps: the step S2 specifically includes:
adding the hollow glass beads/ferroferric oxide/silicon dioxide into an organic solvent, and performing ultrasonic dispersion treatment; then adding polyvinylpyrrolidone, and performing ultrasonic dispersion treatment, filtering and drying to prepare modified hollow glass beads/ferroferric oxide/silicon dioxide;
adding the modified hollow glass beads/ferroferric oxide/silicon dioxide into an inorganic solvent, and performing ultrasonic dispersion treatment; and then adding a catalyst, stirring, adding pyrrole, further stirring, filtering and drying to prepare the hollow glass microsphere/ferroferric oxide/silicon dioxide/polypyrrole microsphere.
3. The preparation method of the hollow glass bead/ferroferric oxide/carbon wave-absorbing powder according to claim 2, characterized by comprising the following steps: the organic solvent is ethanol or acetone, the inorganic solvent is deionized water, and the catalyst comprises ferric chloride;
in the step of preparing modified hollow glass beads/ferroferric oxide/silicon dioxide, 1-6 parts by mass of the hollow glass beads/ferroferric oxide/silicon dioxide, 50-400 parts by mass of ethanol or acetone and 3-8 parts by mass of polyvinylpyrrolidone are used;
in the step of preparing the hollow glass bead/ferroferric oxide/silicon dioxide/polypyrrole microsphere, 1-6 parts by mass of the modified hollow glass bead/ferroferric oxide/silicon dioxide, 100-400 parts by mass of deionized water, 5-10 parts by mass of ferric chloride and 1-5 parts by mass of pyrrole are used.
4. The preparation method of the hollow glass bead/ferroferric oxide/carbon wave-absorbing powder according to claim 1, which is characterized by comprising the following steps: the step S3 specifically includes:
calcining the hollow glass microspheres/ferroferric oxide/silicon dioxide/polypyrrole microspheres for 2-6 hours under the condition of nitrogen at the temperature of 800 ℃ of 500-;
then dispersing the hollow glass beads/ferroferric oxide/silicon dioxide/carbon microspheres into 100-400 parts of 10-30% sodium hydroxide solution for etching, and stirring at the temperature of 40-80 ℃ and the rotating speed of 800-1500 r/min for 10-E
And (3) collecting precipitates by using a magnet for 20 hours, pouring out supernate, washing the supernate by using distilled water for 3-6 times, and drying the precipitates for 8-15 hours in a blast oven at the temperature of 40-80 ℃ to obtain the hollow glass bead/ferroferric oxide/carbon wave-absorbing powder.
5. The method for preparing the hollow glass bead/ferroferric oxide/carbon wave-absorbing powder according to claim 1, wherein the step S1 specifically comprises the following steps:
substep S11, pretreating the hollow glass beads with an alkali solution;
substep S12 converting Fe (CO)5Adding the pretreated hollow glass beads into an alcohol amine solvent, and stirring to obtain a reaction solution; adding an alkali solution and a reducing agent into the reaction solution, stirring, filtering and drying to obtain hollow glass beads/ferroferric oxide with a core/shell structure;
step S13, adding the hollow glass bead/ferroferric oxide into a mixed solution for dispersion treatment; and then adding ethyl orthosilicate, stirring, filtering and drying to obtain the hollow glass microsphere/ferroferric oxide/silicon dioxide with the core/shell structure.
6. The preparation method of the hollow glass bead/ferroferric oxide/carbon wave-absorbing powder according to claim 5, characterized by comprising the following steps: the alcohol amine solvent is one or more of methanolamine, ethanolamine and diethanolamine;
the alkali solution is one or more of NaOH and KOH;
the reducing agent is one or more of hydrazine hydrate and sodium hypophosphite;
the mixed solution comprises absolute ethyl alcohol or acetone, water and weak base solution.
7. The preparation method of the hollow glass bead/ferroferric oxide/carbon wave-absorbing powder according to claim 5, characterized by comprising the following steps: the sub-step S12 specifically includes:
mixing Fe (CO)5Adding the pretreated hollow glass beads into an alcohol amine solvent, and stirring to obtain a reaction solution;
adding an alkali solution into the reaction solution to keep the pH value within the range of 8-10, adding a reducing agent into the reaction solution, and stirring to fully react to obtain a first precipitate; and cleaning the first precipitate by using a first cleaning solution, and drying to obtain the hollow glass bead/ferroferric oxide.
8. The preparation method of the hollow glass bead/ferroferric oxide/carbon wave-absorbing powder according to claim 7, which is characterized by comprising the following steps: the first cleaning solution is deionized water, the alkali solution is a NaOH solution, and the reducing agent is hydrazine hydrate;
the pretreated hollow glass beads are 8-50 parts by mass, and the mass ratio of the hollow glass beads to the hollow glass beads is Fe (CO)55 to 40 parts by mass of the alcohol amine solvent, and 200 to 600 parts by mass of the alcohol amine solventWeighing parts; the mass concentration of the NaOH solution is 5-28%, and the mass concentration of the hydrazine hydrate is 10-50 parts.
9. The preparation method of the hollow glass bead/ferroferric oxide/carbon wave-absorbing powder according to claim 5, characterized by comprising the following steps: the substep S13 specifically includes:
adding the hollow glass beads/ferroferric oxide into a mixed solution of a solvent, water and weak base, and performing ultrasonic dispersion treatment; then adding tetraethoxysilane, and stirring in a water bath to react to obtain a second precipitate;
and cleaning the second precipitate by using a second cleaning solution, and drying to obtain the hollow glass bead/ferroferric oxide/silicon dioxide.
10. The preparation method of the hollow glass bead/ferroferric oxide/carbon wave-absorbing powder according to claim 9, characterized by comprising the following steps: the solvent comprises absolute ethyl alcohol, and the weak base comprises ammonia water;
the hollow glass bead/ferroferric oxide composite material is prepared from 2-10 parts by mass of hollow glass beads/ferroferric oxide, 800-1200 parts by mass of absolute ethyl alcohol, 200-500 parts by mass of water, 20-100 parts by mass of ammonia water and 1-6 parts by mass of ethyl orthosilicate.
11. The hollow glass bead/ferroferric oxide/carbon wave-absorbing powder prepared by the preparation method of the hollow glass bead/ferroferric oxide/carbon wave-absorbing powder according to any one of claims 1 to 10 comprises a hollow glass bead layer serving as a hollow inner core layer, and a ferroferric oxide layer and a carbon layer which are sequentially coated on the outer surface of the hollow inner core layer from inside to outside, wherein a gap is formed between the ferroferric oxide layer and the carbon layer.
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