WO2023029564A1 - Carbon/magnetic electromagnetic wave absorbing material having sandwich structure, and preparation method therefor - Google Patents
Carbon/magnetic electromagnetic wave absorbing material having sandwich structure, and preparation method therefor Download PDFInfo
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- WO2023029564A1 WO2023029564A1 PCT/CN2022/091932 CN2022091932W WO2023029564A1 WO 2023029564 A1 WO2023029564 A1 WO 2023029564A1 CN 2022091932 W CN2022091932 W CN 2022091932W WO 2023029564 A1 WO2023029564 A1 WO 2023029564A1
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- the application belongs to the technical field of electromagnetic materials, and in particular relates to a sandwich-structured carbon/magnetic electromagnetic wave absorbing material and a preparation method thereof.
- Electromagnetic pollution has become the fifth largest public hazard after wastewater, waste gas, solid waste and noise. Relevant reports indicate that electromagnetic pollution will replace noise pollution in this century and become one of the five major physical pollutions. At present, using electromagnetic wave absorbing materials to weaken or eliminate electromagnetic wave pollution is an effective method.
- ferrite or carbon materials are commonly used as electromagnetic wave absorbing materials in the market.
- Fe3iron tetroxide, carbonyl iron and magnetic electromagnetic wave absorbing materials are heavy in weight, and the prepared materials are thick and heavy, which limits their application range.
- carbon-based electromagnetic wave absorbing materials have the advantages of light weight, adjustable frequency range, and good compatibility with the organic/inorganic phase interface of the matrix.
- Graphite powder, carbon black, carbon nanotubes, chopped carbon fibers and activated carbon fibers have been reported as carbon-based electromagnetic wave protection functional fillers.
- the main factor determining the absorbing characteristics of carbon materials is electrical resistance, but its high conductivity makes it easy to reflect electromagnetic waves and affect the absorption efficiency.
- Electromagnetic wave absorbing materials are also improved by means of dielectric loss materials, a layer of magnetic loss materials, etc.
- the existing technology proposes a method for preparing electromagnetic wave absorbing materials with a sandwich structure, but there are still certain defects in the preparation process. It is not an obvious multi-layer structure, but a hybrid material, and the number of layers cannot be freely controlled. Self-regulated electromagnetic wave absorption performance.
- each exemplary embodiment of the present application provides a carbon/magnetic electromagnetic wave absorbing material with a sandwich structure and a preparation method thereof.
- the micro-flaky particles with multi-layer structures such as carbon layers and magnetic layers formed by bit hybridization can effectively absorb electromagnetic waves and have very broad application prospects.
- a carbon/magnetic electromagnetic wave absorbing material with a sandwich structure comprising a first composite layer, the first composite layer including a first inner layer, a first middle layer and a first outer layer, wherein the The first inner layer is ferroferric oxide, the first middle layer is a carbon layer, and the first outer layer is nano ferric oxide particles.
- the absorbing material further comprises a second composite layer, the second composite layer includes a second inner layer of iron tetraoxide, a second middle layer of carbon, and a nanometer layer of iron tetraoxide.
- the second outer layer of the particle is not limited to a second composite layer, the second composite layer includes a second inner layer of iron tetraoxide, a second middle layer of carbon, and a nanometer layer of iron tetraoxide.
- the present application provides a method for preparing a sandwich structure carbon/magnetic electromagnetic wave absorbing material, which includes the following steps, (1) by dissolving iron salt in diethylene glycol, preparing a mass fraction of 8 % to 10% metal salt solution S1; (2) by adding a buffering agent to the solution S1, stirring and dissolving, and standing for 5 minutes to prepare a solution S2; (3) by transferring the S2 solution to an autoclave , pass through the protective gas, keep at 200°C for 8 hours, shake once every 30 minutes to prevent the agglomeration of particles, and obtain ferric oxide, then take out the ferric oxide, wash and dry with deionized water , obtain flaky ferric oxide; (4) prepare solution S3 by configuring the dopamine hydrochloride of 1g/L to 2g/L and adjusting the pH to 8.5; (5) prepare the flaky ferric oxide by step (3) Iron ferric oxide is put into the solution S3, wherein the mass fraction of the sheet-shaped ferric iron tetro
- the iron salt is selected from ferric sulfate and ferric chloride.
- the sandwich structure carbon/magnetic electromagnetic wave absorbing material includes a first combined layer, the first combined layer includes a first inner layer, a first middle layer and a first outer layer, and the first and other The inner layer is iron ferric oxide, the first middle layer is a carbon layer, and the first outer layer is nano ferric oxide particles.
- the buffer is citric acid-sodium citrate.
- the protective gas is nitrogen.
- steps (4)-(7) are repeated to prepare an electromagnetic wave absorbing material with multiple combined layers.
- the sandwich-structured carbon/magnetic electromagnetic wave absorbing material prepared by cross-hybridization of ferroferric oxide and carbon in this application can significantly improve the electromagnetic wave absorbing performance of the material, has both dielectric loss and magnetic loss properties, and is light in weight. It can be used as an electromagnetic wave absorber and combined with textiles, polymer adhesives, etc. to prepare light and soft electromagnetic wave absorbing composite materials, and has very broad application prospects.
- Fig. 1 is the SEM picture of the carbon-magnetic electromagnetic wave absorbing material of the sandwich structure prepared by the present application;
- Fig. 2 is the carbon-magnetic electromagnetic wave absorbing material electromagnetic wave absorption performance figure of the sandwich structure that the embodiment 1 of the present application makes;
- Fig. 3 is the carbon-magnetic electromagnetic wave absorbing material electromagnetic wave absorption performance figure of the sandwich structure that the embodiment 2 of the present application makes;
- Fig. 4 is a diagram of the electromagnetic wave absorption performance of the sandwich-structured carbon-magnetic electromagnetic wave absorbing material prepared in Example 3 of the present application.
- step 3 transfer the solution prepared in step 2 to a stainless steel autoclave lined with Teflon, keep it at 200°C for 8 hours, feed nitrogen to protect ferric oxide from oxidation during the reaction, and simultaneously Vibrate once in 30 minutes to prevent the agglomeration of particles; then take it out and wash it with deionized water and dry it to obtain flake ferric oxide;
- Dopamine hydrochloride of 1g/L is configured, and the pH of the solution is adjusted to 8.5 by using a citric acid-sodium citrate buffer;
- step 5 Place the material prepared in step 5 into a nitrogen atmosphere at 450°C for carbonization treatment for 1 hour, and then take it out;
- the prepared material is ferroferric oxide as the inner layer, the middle layer is a carbon layer, and the outermost layer is nanometer ferric oxide particles, the conductivity is 0.2S/cm, and the special sandwich structure has certain electromagnetic wave absorption performance, as shown in Figure 2 below.
- step 3 transfer the solution prepared in step 2 to a stainless steel autoclave lined with Teflon, keep it at 200°C for 8 hours, feed nitrogen to protect ferric oxide from oxidation during the reaction, and simultaneously Vibrate once in 30 minutes to prevent the agglomeration of particles; then take it out and wash it with deionized water and dry it to obtain flake ferric oxide;
- step 5 Place the material prepared in step 5 into a nitrogen atmosphere at 600°C for carbonization treatment for 1 hour, and then take it out;
- the prepared material is ferroferric oxide as the inner layer, the middle layer is carbon layer, the outermost layer is nanometer ferric oxide particles, the conductivity is 0.8S/cm, and the special sandwich structure has good electromagnetic wave Absorption performance, controlling the carbonization temperature of dopamine can effectively improve the electromagnetic wave absorption performance of the material, as shown in Figure 3 below.
- step 3 transfer the solution prepared in step 2 to a stainless steel autoclave lined with Teflon, keep it at 200°C for 8 hours, feed nitrogen to protect ferric oxide from oxidation during the reaction, and simultaneously Vibrate once in 30 minutes to prevent the agglomeration of particles; then take it out and wash it with deionized water and dry it to obtain flake ferric oxide;
- step 5 Place the material prepared in step 5 into a nitrogen atmosphere at 600°C for carbonization treatment for 1 hour, and then take it out;
- the prepared material is ferroferric oxide as the inner layer, and the outer layer is alternately loaded with carbon layer and nanometer ferric oxide particle layer.
- the conductivity is 0.85S/cm.
- the multi-layer special sandwich structure has excellent electromagnetic wave absorption Performance, we found that the electromagnetic wave absorption performance of the material becomes stronger, the minimum loss reaches -19dB, and the bandwidth of the effective loss ( ⁇ -10dB) in the 2-18GHz band reaches 12GHz, as shown in Figure 4 below.
- the coating, carbonization and other preparation processes involved in this application generate a carbon layer in situ on the surface of the flake ferric oxide, so that the product structure is more stable, and the carbonization rate of dopamine can be controlled by the carbonization temperature.
- the preparation process controls the number of layers in order to achieve the maximum absorption performance under different electromagnetic wave frequency bands.
- the dispersion of various materials prepared by it is not stable, and the stability is not good.
- this patent is loaded layer by layer, and the thickness of each layer is controllable.
- the prepared material has stable performance.
- the carbon layer has a great influence on the performance of the material.
- This patent uses dopamine coating and carbonization technology to prepare carbon layers with different conductivity to control the electromagnetic wave impedance matching and coordinated electromagnetic wave loss of the material as a whole.
Abstract
Disclosed in the present application are a carbon/magnetic electromagnetic wave absorbing material having a sandwich structure and a preparation method therefor. an iron salt is utilized and piece-shaped iron(II, III) oxide is prepared; 5-10 g of piece-shaped iron(II, III) oxide are coated with a polydopamine and a piece-shaped material is obtained; then the polydopamine-coated piece-shaped material is placed in a nitrogen atmosphere at 450-600 °C, carbonization treatment is performed for 1 hour, and a material is obtained; same is added into 100 ml of distilled water, then 5 g of a blend of iron(III) chloride and iron(II) chloride at a molar ratio of 2:1 is added, and upon stirring and dissolving, 8 ml of ammonia water is gradually added in a dropwise fashion, a reaction is performed for 1 hour in a 50 °C water bath, and then cleaning is performed. A structure of the carbon/magnetic electromagnetic wave absorbing material having a sandwich structure is iron(II, III) oxide as an inner layer, a carbon layer as an intermediate layer, and iron(II, III) oxide nanoparticles as an outermost layer; the electromagnetic wave absorption property of a material can be distinctly improved, same has both dielectric loss and magnetic loss properties, has low mass, and has extremely broad application prospects.
Description
相关申请related application
本申请要求于2021年9月6日提交中国专利局、申请号为202111038277X、申请名称为“一种三明治结构的碳/磁电磁波吸收材料及其制备方法”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。This application claims the priority of the Chinese patent application submitted to the China Patent Office on September 6, 2021, with the application number 202111038277X, and the application name "a carbon/magnetic and electromagnetic wave absorbing material with a sandwich structure and its preparation method", all of which The contents are incorporated by reference in this application.
本申请属于电磁材料技术领域，具体涉及一种三明治结构的碳/磁电磁波吸收材料及其制备方法。The application belongs to the technical field of electromagnetic materials, and in particular relates to a sandwich-structured carbon/magnetic electromagnetic wave absorbing material and a preparation method thereof.
随着电子、电气技术的迅速发展，电磁能利用范围不断扩大，随之而来的就是电磁辐射污染。电磁污染问题已成为继废水、废气、固体废弃物和噪音之后的第5大公害，有关报道表明本世纪电磁污染将取代噪声污染而成为主要的5大物理污染之一。目前，利用电磁波吸收材料来减弱或消除电磁波污染是一种有效的方法。With the rapid development of electronics and electrical technology, the scope of electromagnetic energy utilization continues to expand, followed by electromagnetic radiation pollution. Electromagnetic pollution has become the fifth largest public hazard after wastewater, waste gas, solid waste and noise. Relevant reports indicate that electromagnetic pollution will replace noise pollution in this century and become one of the five major physical pollutions. At present, using electromagnetic wave absorbing materials to weaken or eliminate electromagnetic wave pollution is an effective method.
目前市场上普遍使用铁氧体或者碳材料作为电磁波吸收材料。四氧化三铁、羰基铁以及磁性电磁波吸收材料质量重，所制备的材料厚重，限制了其应用的范围。另一方面，碳基电磁波吸收材料具有重量轻、频率范围可调、与基体的有机/无机相界面相容性好的优点。石墨粉、炭黑、碳纳米管、短切碳纤维和活性碳纤维作为碳基电磁波防护功能填料均已有研究报道。但是，碳材料决定其吸波特性的主要因素是电阻，但是其电导率较高，容易反射电磁波，影响吸收效率。为此，许多研究者在碳材料上负载磁性粒子，包括石墨粉镀镍、碳纳米管镀镍、以及负载纳米铁氧体粒子等方式来提高材料的电磁波吸收性能，另外也有通过涂覆一层介电损耗材料、一层磁损耗材料等方式也改善电磁波吸收材料。现有技术提出了制备三明治结构的电磁波吸收材料的方法，但是在制备工艺上还存在着一定的缺陷，不是明显的多层结构，而是混杂材料，不能自由的进行层数的控制，从而不能自主调控电磁波吸收性能。At present, ferrite or carbon materials are commonly used as electromagnetic wave absorbing materials in the market. Fe3iron tetroxide, carbonyl iron and magnetic electromagnetic wave absorbing materials are heavy in weight, and the prepared materials are thick and heavy, which limits their application range. On the other hand, carbon-based electromagnetic wave absorbing materials have the advantages of light weight, adjustable frequency range, and good compatibility with the organic/inorganic phase interface of the matrix. Graphite powder, carbon black, carbon nanotubes, chopped carbon fibers and activated carbon fibers have been reported as carbon-based electromagnetic wave protection functional fillers. However, the main factor determining the absorbing characteristics of carbon materials is electrical resistance, but its high conductivity makes it easy to reflect electromagnetic waves and affect the absorption efficiency. For this reason, many researchers load magnetic particles on carbon materials, including nickel-plated graphite powder, nickel-plated carbon nanotubes, and loaded nano-ferrite particles to improve the electromagnetic wave absorption performance of the material. Electromagnetic wave absorbing materials are also improved by means of dielectric loss materials, a layer of magnetic loss materials, etc. The existing technology proposes a method for preparing electromagnetic wave absorbing materials with a sandwich structure, but there are still certain defects in the preparation process. It is not an obvious multi-layer structure, but a hybrid material, and the number of layers cannot be freely controlled. Self-regulated electromagnetic wave absorption performance.
发明内容Contents of the invention
为了克服现有技术中电磁波吸收材料产品质量重、成型困难、电磁波损耗机制单一等问题，本申请各示例性实施例提供了一种三明治结构的碳/磁电磁波吸收材料及其制 备方法，通过原位杂化方式形成碳层、磁层等多层结构的微米片状颗粒，可以针对电磁波进行有效的吸收，具有非常广阔的应用前景。In order to overcome the problems of heavy product quality, difficult molding, and single electromagnetic wave loss mechanism in the prior art, each exemplary embodiment of the present application provides a carbon/magnetic electromagnetic wave absorbing material with a sandwich structure and a preparation method thereof. The micro-flaky particles with multi-layer structures such as carbon layers and magnetic layers formed by bit hybridization can effectively absorb electromagnetic waves and have very broad application prospects.
本申请提供的技术方案：一种三明治结构的碳/磁电磁波吸收材料，包括第一组合层，所述第一组合层包括第一内层、第一中间层和第一外层，其中，所述第一内层为四氧化三铁，所述第一中间层为碳层，所述第一外层为纳米四氧化三铁颗粒。The technical solution provided by the application: a carbon/magnetic electromagnetic wave absorbing material with a sandwich structure, comprising a first composite layer, the first composite layer including a first inner layer, a first middle layer and a first outer layer, wherein the The first inner layer is ferroferric oxide, the first middle layer is a carbon layer, and the first outer layer is nano ferric oxide particles.
在一实施例中，所述吸收材料还包含第二组合层，所述第二组合层包括为四氧化三铁的第二内层、为碳层的第二中间层以及为纳米四氧化三铁颗粒的第二外层。In one embodiment, the absorbing material further comprises a second composite layer, the second composite layer includes a second inner layer of iron tetraoxide, a second middle layer of carbon, and a nanometer layer of iron tetraoxide. The second outer layer of the particle.
作为本申请的另一方面，本申请提供一种三明治结构碳/磁电磁波吸收材料的制备方法，其包括以下步骤，(1)通过将铁盐溶解到二乙二醇中，制备质量分数为8％至10％金属盐溶液S1；(2)通过向所述溶液S1中加入缓冲剂，并搅拌溶解后静置5分钟，制备溶液S2；(3)通过将所述S2溶液转移至高压釜中，通入保护气体，在200℃下保持8小时，每隔30min进行震动1次来防止颗粒的团聚，得到四氧化三铁，然后取出所述四氧化三铁，并用去离子水洗净烘干，得到片状四氧化三铁；(4)通过配置1g/L至2g/L的盐酸多巴胺并调节pH至8.5，制备溶液S3；(5)通过将步骤(3)制备的所述片状四氧化三铁放入所述溶液S3中，其中所述片状四氧化三铁的质量分数为9％至11％，然后在30℃水浴中震荡反应10至24小时，得到包覆聚多巴胺的片状材料；(6)将所述包覆聚多巴胺的片状材料置入450℃至600℃的氮气气氛中碳化处理1小时得到材料S4；(7)将每10g的所述材料S4加入到100ml蒸馏水中，然后加入摩尔比为2:1的氯化铁和氯化亚铁共混物5g搅拌溶解后，逐渐滴入8ml氨水，在50℃水浴中反应1小时，洗净以得到所述三明治结构碳/磁电磁波吸收材料。As another aspect of the present application, the present application provides a method for preparing a sandwich structure carbon/magnetic electromagnetic wave absorbing material, which includes the following steps, (1) by dissolving iron salt in diethylene glycol, preparing a mass fraction of 8 % to 10% metal salt solution S1; (2) by adding a buffering agent to the solution S1, stirring and dissolving, and standing for 5 minutes to prepare a solution S2; (3) by transferring the S2 solution to an autoclave , pass through the protective gas, keep at 200°C for 8 hours, shake once every 30 minutes to prevent the agglomeration of particles, and obtain ferric oxide, then take out the ferric oxide, wash and dry with deionized water , obtain flaky ferric oxide; (4) prepare solution S3 by configuring the dopamine hydrochloride of 1g/L to 2g/L and adjusting the pH to 8.5; (5) prepare the flaky ferric oxide by step (3) Iron ferric oxide is put into the solution S3, wherein the mass fraction of the sheet-shaped ferric iron tetroxide is 9% to 11%, and then shaken and reacted in a water bath at 30°C for 10 to 24 hours to obtain a polydopamine-coated sheet (6) put the polydopamine-coated sheet material into a nitrogen atmosphere at 450°C to 600°C for carbonization treatment for 1 hour to obtain material S4; (7) add every 10g of the material S4 to 100ml In distilled water, then add 5g of ferric chloride and ferrous chloride blend with a molar ratio of 2:1 and stir to dissolve, then gradually drop in 8ml of ammonia water, react in a water bath at 50°C for 1 hour, and wash to obtain the sandwich Structural carbon/magnetic electromagnetic wave absorbing materials.
在一实施例中，所述铁盐选自硫酸铁、氯化铁。In one embodiment, the iron salt is selected from ferric sulfate and ferric chloride.
在一实施例中，所述三明治结构碳/磁电磁波吸收材料，包括第一组合层，所述第一组合层包括第一内层、第一中间层以及第一外层，所述第一其内层为四氧化三铁，所述第一中间层为碳层，所述第一外层为纳米四氧化三铁颗粒。In one embodiment, the sandwich structure carbon/magnetic electromagnetic wave absorbing material includes a first combined layer, the first combined layer includes a first inner layer, a first middle layer and a first outer layer, and the first and other The inner layer is iron ferric oxide, the first middle layer is a carbon layer, and the first outer layer is nano ferric oxide particles.
在一实施例中，所述缓冲剂为柠檬酸-柠檬酸钠。In one embodiment, the buffer is citric acid-sodium citrate.
在一实施例中，所述保护气体为氮气。In one embodiment, the protective gas is nitrogen.
在一实施例中，重复步骤(4)-(7)，以制备具有多个组合层的电磁波吸收材料。In one embodiment, steps (4)-(7) are repeated to prepare an electromagnetic wave absorbing material with multiple combined layers.
本申请的有益效果如下：The beneficial effects of the application are as follows:
本申请以四氧化三铁和炭交叉杂化成型制备的三明治结构的片状碳/磁电磁波吸收材料可以明显的改善材料的电磁波吸收性能，兼具介电损耗和磁损耗性能，而且质量轻，可以作为电磁波吸收剂与纺织品、高分子粘合剂等复合制备轻质且柔软的电磁波吸收复合材料，具有非常广阔的应用前景。The sandwich-structured carbon/magnetic electromagnetic wave absorbing material prepared by cross-hybridization of ferroferric oxide and carbon in this application can significantly improve the electromagnetic wave absorbing performance of the material, has both dielectric loss and magnetic loss properties, and is light in weight. It can be used as an electromagnetic wave absorber and combined with textiles, polymer adhesives, etc. to prepare light and soft electromagnetic wave absorbing composite materials, and has very broad application prospects.
图1为本申请制备的三明治结构的碳-磁电磁波吸收材料的SEM图片；Fig. 1 is the SEM picture of the carbon-magnetic electromagnetic wave absorbing material of the sandwich structure prepared by the present application;
图2为本申请实施例1制得的三明治结构的碳-磁电磁波吸收材料电磁波吸收性能图；Fig. 2 is the carbon-magnetic electromagnetic wave absorbing material electromagnetic wave absorption performance figure of the sandwich structure that the embodiment 1 of the present application makes;
图3为本申请实施例2制得的三明治结构的碳-磁电磁波吸收材料电磁波吸收性能图；Fig. 3 is the carbon-magnetic electromagnetic wave absorbing material electromagnetic wave absorption performance figure of the sandwich structure that the embodiment 2 of the present application makes;
图4为本申请实施例3制得的三明治结构的碳-磁电磁波吸收材料电磁波吸收性能图。Fig. 4 is a diagram of the electromagnetic wave absorption performance of the sandwich-structured carbon-magnetic electromagnetic wave absorbing material prepared in Example 3 of the present application.
下面结合附图对本申请作更进一步的说明。The application will be further described below in conjunction with the accompanying drawings.
实施例1：Example 1:
(1)将2g无水氯化铁溶解到20ml二乙二醇中，制备金属盐溶液；(1) 2g anhydrous ferric chloride is dissolved in 20ml diethylene glycol, prepare metal salt solution;
(2)将2g柠檬酸-柠檬酸钠缓冲剂(pH＝10)加入到步骤1溶液中，搅拌溶解后静置5分钟，制备溶液；(2) Add 2 g of citric acid-sodium citrate buffer (pH=10) into the solution in step 1, stir and dissolve, then let stand for 5 minutes to prepare the solution;
(3)将步骤2制备的溶液转移至内衬为特氟龙的不锈钢高压釜中，在200℃下保持8小时，在反应过程中通入氮气保护四氧化三铁不被氧化，同时每隔30min进行震动1次来防止颗粒的团聚；然后取出用去离子水洗净烘干，得到片状四氧化三铁；(3) transfer the solution prepared in step 2 to a stainless steel autoclave lined with Teflon, keep it at 200°C for 8 hours, feed nitrogen to protect ferric oxide from oxidation during the reaction, and simultaneously Vibrate once in 30 minutes to prevent the agglomeration of particles; then take it out and wash it with deionized water and dry it to obtain flake ferric oxide;
(4)配置1g/L的盐酸多巴胺，利用柠檬酸-柠檬酸钠缓冲剂将溶液pH调节至8.5；(4) Dopamine hydrochloride of 1g/L is configured, and the pH of the solution is adjusted to 8.5 by using a citric acid-sodium citrate buffer;
(5)将5g片状四氧化三铁放入50ml的步骤4制备的溶液中，然后在30℃水浴中震荡反应10小时，得到包覆聚多巴胺的片状材料，聚多巴胺厚度为5nm；(5) Put 5g of flaky iron ferric oxide into 50ml of the solution prepared in step 4, then shake and react in a water bath at 30°C for 10 hours to obtain a sheet material coated with polydopamine, and the thickness of polydopamine is 5nm;
(6)将步骤5制备的材料置入450℃氮气气氛中碳化处理1小时，然后取出；(6) Place the material prepared in step 5 into a nitrogen atmosphere at 450°C for carbonization treatment for 1 hour, and then take it out;
(7)将10g步骤6制备的材料加入到100ml蒸馏水中，然后加入摩尔比为2:1的氯化铁和氯化亚铁共混物5g，搅拌溶解后逐渐滴入8ml氨水，在50℃水浴中反应1小时，然后洗净备用；(7) Add 10 g of the material prepared in step 6 to 100 ml of distilled water, then add 5 g of ferric chloride and ferrous chloride blend with a molar ratio of 2:1, stir and dissolve, and gradually add 8 ml of ammonia water, at 50 ° C React in a water bath for 1 hour, then wash and set aside;
(8)所制备的材料为四氧化三铁为内层，中间层为碳层，最外层为纳米四氧化三铁颗粒，电导率为0.2S/cm，特殊的三明治结构具有一定的电磁波吸收性能，如下图2 所示。(8) The prepared material is ferroferric oxide as the inner layer, the middle layer is a carbon layer, and the outermost layer is nanometer ferric oxide particles, the conductivity is 0.2S/cm, and the special sandwich structure has certain electromagnetic wave absorption performance, as shown in Figure 2 below.
实施例2：Example 2:
(1)将10g无水氯化铁溶解到80ml二乙二醇中，制备金属盐溶液；(1) 10g anhydrous ferric chloride is dissolved in 80ml diethylene glycol, prepare metal salt solution;
(2)将5g柠檬酸-柠檬酸钠缓冲剂(pH＝10)加入到步骤1溶液中，搅拌溶解后静置5分钟，制备溶液；(2) Add 5 g of citric acid-sodium citrate buffer (pH=10) into the solution in step 1, stir and dissolve, then let stand for 5 minutes to prepare the solution;
(3)将步骤2制备的溶液转移至内衬为特氟龙的不锈钢高压釜中，在200℃下保持8小时，在反应过程中通入氮气保护四氧化三铁不被氧化，同时每隔30min进行震动1次来防止颗粒的团聚；然后取出用去离子水洗净烘干，得到片状四氧化三铁；(3) transfer the solution prepared in step 2 to a stainless steel autoclave lined with Teflon, keep it at 200°C for 8 hours, feed nitrogen to protect ferric oxide from oxidation during the reaction, and simultaneously Vibrate once in 30 minutes to prevent the agglomeration of particles; then take it out and wash it with deionized water and dry it to obtain flake ferric oxide;
(4)配置2g/L的盐酸多巴胺，利用柠檬酸-柠檬酸钠缓冲剂将溶液pH调节至8.5；(4) configure 2g/L dopamine hydrochloride, and use citric acid-sodium citrate buffer to adjust the pH of the solution to 8.5;
(5)将10g片状四氧化三铁放入80ml的步骤4制备的溶液中，然后在30℃水浴中震荡反应24小时，得到包覆聚多巴胺的片状材料，聚多巴胺厚度为10nm；(5) Put 10 g of flaky iron ferric oxide into 80 ml of the solution prepared in step 4, then shake and react in a water bath at 30° C. for 24 hours to obtain a sheet material coated with polydopamine, and the thickness of polydopamine is 10 nm;
(6)将步骤5制备的材料置入600℃氮气气氛中碳化处理1小时，然后取出；(6) Place the material prepared in step 5 into a nitrogen atmosphere at 600°C for carbonization treatment for 1 hour, and then take it out;
(7)将10g步骤6制备的材料加入到100ml蒸馏水中，然后加入摩尔比为2:1的氯化铁和氯化亚铁共混物5g，搅拌溶解后逐渐滴入8ml氨水，在50℃水浴中反应1小时，然后洗净备用；(7) Add 10 g of the material prepared in step 6 to 100 ml of distilled water, then add 5 g of ferric chloride and ferrous chloride blend with a molar ratio of 2:1, stir and dissolve, and gradually add 8 ml of ammonia water, at 50 ° C React in a water bath for 1 hour, then wash and set aside;
(8)所制备的材料为四氧化三铁为内层，中间层为碳层，最外层为纳米四氧化三铁颗粒，电导率为0.8S/cm，特殊的三明治结构具有很好的电磁波吸收性能，控制好多巴胺的碳化温度，可以有效的提高材料的电磁波吸收性能，如下图3所示。(8) The prepared material is ferroferric oxide as the inner layer, the middle layer is carbon layer, the outermost layer is nanometer ferric oxide particles, the conductivity is 0.8S/cm, and the special sandwich structure has good electromagnetic wave Absorption performance, controlling the carbonization temperature of dopamine can effectively improve the electromagnetic wave absorption performance of the material, as shown in Figure 3 below.
实施例3：Example 3:
(1)将10g无水氯化铁溶解到80ml二乙二醇中，制备金属盐溶液；(1) 10g anhydrous ferric chloride is dissolved in 80ml diethylene glycol, prepare metal salt solution;
(2)将柠檬酸-柠檬酸钠5g缓冲剂(pH＝10)加入到步骤1溶液中，搅拌溶解后静置5分钟，制备溶液；(2) Add 5 g of citric acid-sodium citrate buffer (pH=10) to the solution in step 1, stir and dissolve, then let stand for 5 minutes to prepare a solution;
(3)将步骤2制备的溶液转移至内衬为特氟龙的不锈钢高压釜中，在200℃下保持8小时，在反应过程中通入氮气保护四氧化三铁不被氧化，同时每隔30min进行震动1次来防止颗粒的团聚；然后取出用去离子水洗净烘干，得到片状四氧化三铁；(3) transfer the solution prepared in step 2 to a stainless steel autoclave lined with Teflon, keep it at 200°C for 8 hours, feed nitrogen to protect ferric oxide from oxidation during the reaction, and simultaneously Vibrate once in 30 minutes to prevent the agglomeration of particles; then take it out and wash it with deionized water and dry it to obtain flake ferric oxide;
(4)配置2g/L的盐酸多巴胺，利用柠檬酸-柠檬酸钠缓冲剂将溶液pH调节至8.5；(4) configure 2g/L dopamine hydrochloride, and use citric acid-sodium citrate buffer to adjust the pH of the solution to 8.5;
(5)将10g片状四氧化三铁放入80ml的步骤4制备的溶液中，然后在30℃水浴中 震荡反应24小时，得到包覆聚多巴胺的片状材料，聚多巴胺厚度为10nm；(5) Put 10g flake iron ferric oxide into the solution prepared in step 4 of 80ml, then shake and react in a water bath at 30°C for 24 hours to obtain a sheet material coated with polydopamine, and the thickness of polydopamine is 10nm;
(6)将步骤5制备的材料置入600℃氮气气氛中碳化处理1小时，然后取出；(6) Place the material prepared in step 5 into a nitrogen atmosphere at 600°C for carbonization treatment for 1 hour, and then take it out;
(7)将10g步骤6制备的材料加入到100ml蒸馏水中，然后加入摩尔比为2:1的氯化铁和氯化亚铁共混物5g，搅拌溶解后逐渐滴入8ml氨水，在50℃水浴中反应1小时，然后洗净备用；(7) Add 10 g of the material prepared in step 6 to 100 ml of distilled water, then add 5 g of ferric chloride and ferrous chloride blend with a molar ratio of 2:1, stir and dissolve, and gradually add 8 ml of ammonia water, at 50 ° C React in a water bath for 1 hour, then wash and set aside;
(8)重复4-7步骤1次，再次进行聚多巴胺的包覆、碳化及最外层四氧化三铁的负载；(8) Repeat steps 4-7 once, and carry out the coating and carbonization of polydopamine and the loading of the outermost layer of iron tetroxide again;
(9)所制备的材料为四氧化三铁为内层，外面为碳层、纳米四氧化三铁颗粒层交替负载，电导率为0.85S/cm，多层的特殊三明治结构具有优异的电磁波吸收性能，我们发现材料的电磁波吸收性能变强，最低损耗达到了-19dB，在2-18GHz波段范围有效损耗(＜-10dB)的频宽达到了12GHz，如下图4所示。(9) The prepared material is ferroferric oxide as the inner layer, and the outer layer is alternately loaded with carbon layer and nanometer ferric oxide particle layer. The conductivity is 0.85S/cm. The multi-layer special sandwich structure has excellent electromagnetic wave absorption Performance, we found that the electromagnetic wave absorption performance of the material becomes stronger, the minimum loss reaches -19dB, and the bandwidth of the effective loss (<-10dB) in the 2-18GHz band reaches 12GHz, as shown in Figure 4 below.
本申请所涉及的包覆、碳化等制备工艺，通过在片状四氧化三铁表面进行原位生成碳层，所生产的产品结构更加稳定,通过碳化温度来控制多巴胺的碳化率，同时可以通过制备工艺进行层数的控制，以便达到不同电磁波频段下最大吸收性能。相比于其他技术进行多种材料的共混及杂化，其制备的各种材料分散规律不定，稳定性不佳，而本专利是一层一层的进行负载，每层的厚度可控，制备出的材料性能稳定。碳层对材料性能影响较大，本专利利用多巴胺包覆及碳化技术进行不同导电率碳层的制备，来控制材料整体的电磁波阻抗匹配及协同电磁波损耗。The coating, carbonization and other preparation processes involved in this application generate a carbon layer in situ on the surface of the flake ferric oxide, so that the product structure is more stable, and the carbonization rate of dopamine can be controlled by the carbonization temperature. The preparation process controls the number of layers in order to achieve the maximum absorption performance under different electromagnetic wave frequency bands. Compared with the blending and hybridization of various materials by other technologies, the dispersion of various materials prepared by it is not stable, and the stability is not good. However, this patent is loaded layer by layer, and the thickness of each layer is controllable. The prepared material has stable performance. The carbon layer has a great influence on the performance of the material. This patent uses dopamine coating and carbonization technology to prepare carbon layers with different conductivity to control the electromagnetic wave impedance matching and coordinated electromagnetic wave loss of the material as a whole.
以上所述仅是本申请的优选实施方式，应当指出：对于本技术领域的普通技术人员来说，在不脱离本申请原理的前提下，还可以做出若干改进和润饰，这些改进和润饰也应视为本申请的保护范围。The above is only a preferred embodiment of the application, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the application, some improvements and modifications can also be made, and these improvements and modifications are also It should be regarded as the protection scope of this application.
Claims (8)
- 一种三明治结构的碳/磁电磁波吸收材料，其中，所述三明治结构碳/磁电磁波吸收材料，包括第一组合层，所述第一组合层包括第一内层、第一中间层和第一外层，其中，所述第一内层为四氧化三铁，所述第一中间层为碳层，所述第一外层为纳米四氧化三铁颗粒。A carbon/magnetic and electromagnetic wave absorbing material with a sandwich structure, wherein the carbon/magnetic and electromagnetic wave absorbing material with a sandwich structure includes a first composite layer, and the first composite layer includes a first inner layer, a first middle layer and a first The outer layer, wherein the first inner layer is ferric oxide, the first middle layer is a carbon layer, and the first outer layer is nano ferric oxide particles.
- 如权利要求1所述的电磁波吸收材料，其中，所述吸收材料还包含第二组合层，所述第二组合层包括为四氧化三铁的第二内层、为碳层的第二中间层以及为纳米四氧化三铁颗粒的第二外层。The electromagnetic wave absorbing material according to claim 1, wherein the absorbing material further comprises a second composite layer, the second composite layer includes a second inner layer of ferric oxide and a second middle layer of carbon and the second outer layer of nano ferric oxide particles.
- 一种三明治结构碳/磁电磁波吸收材料的制备方法，包括：A method for preparing a sandwich carbon/magnetic and electromagnetic wave absorbing material, comprising:(1)通过将铁盐溶解到二乙二醇中，制备得到质量分数为8％至10％金属盐溶液S1；(1) By dissolving the iron salt into diethylene glycol, a metal salt solution S1 with a mass fraction of 8% to 10% is prepared;(2)通过向所述溶液S1中加入缓冲剂，并搅拌溶解后静置5分钟，制备得到溶液S2；(2) By adding a buffer into the solution S1, stirring and dissolving, and standing for 5 minutes, the solution S2 is prepared;(3)通过将所述溶液S2转移至高压釜中，通入保护气体，在200℃下保持8小时，每隔30min进行震动1次来防止颗粒的团聚，得到四氧化三铁，然后取出所述四氧化三铁，并用去离子水洗净烘干，得到片状四氧化三铁；(3) By transferring the solution S2 into an autoclave, introducing a protective gas, keeping it at 200° C. for 8 hours, and vibrating once every 30 minutes to prevent the agglomeration of the particles to obtain ferric oxide, and then take out the Describe ferric oxide, and wash and dry with deionized water, obtain flaky iron ferric oxide;(4)通过配置1g/L至2g/L的盐酸多巴胺并调节pH至8.5，制备得到溶液S3；(4) Prepare solution S3 by configuring 1g/L to 2g/L dopamine hydrochloride and adjusting the pH to 8.5;(5)通过将步骤(3)制备的所述片状四氧化三铁放入所述溶液S3中，其中所述片状四氧化三铁的质量分数为9％至11％，然后在30℃水浴中震荡反应10至24小时，得到包覆聚多巴胺的片状材料；(5) Put the flake ferric iron tetroxide prepared in step (3) into the solution S3, wherein the mass fraction of the flake ferric ferric oxide is 9% to 11%, and then Shaking and reacting in a water bath for 10 to 24 hours to obtain a sheet material coated with polydopamine;(6)将所述包覆聚多巴胺的片状材料置入450℃至600℃的氮气气氛中碳化处理1小时得到材料S4；(6) carbonizing the polydopamine-coated sheet material in a nitrogen atmosphere at 450°C to 600°C for 1 hour to obtain material S4;(7)将每10g的所述材料S4加入到100ml蒸馏水中，然后加入摩尔比为2:1的氯化铁和氯化亚铁共混物5g搅拌溶解后，逐渐滴入8ml氨水，在50℃水浴中反应1小时，洗净以得到所述三明治结构碳/磁电磁波吸收材料。(7) The material S4 of every 10g is added to 100ml distilled water, then add ferric chloride and ferrous chloride blend 5g that molar ratio is 2:1 after stirring and dissolving, drip into 8ml ammoniacal liquor gradually, at 50 °C in a water bath for 1 hour, and washed to obtain the sandwich structure carbon/magnetic electromagnetic wave absorbing material.
- 如权利要求3所述的方法，其中，步骤(1)中所述铁盐选自硫酸铁、氯化铁。The method according to claim 3, wherein the iron salt described in step (1) is selected from ferric sulfate and ferric chloride.
- 如权利要求3所述的方法，其中，步骤(7)得到的所述三明治结构碳/磁电磁波吸收材料包括第一组合层，所述第一组合层包括第一内层、第一中间层以及第一外层，所述第一内层为四氧化三铁，所述第一中间层为碳层，所述第一外层为纳米四氧化三铁颗粒。The method according to claim 3, wherein the sandwich structure carbon/magnetic electromagnetic wave absorbing material obtained in step (7) comprises a first combined layer, and the first combined layer comprises a first inner layer, a first middle layer and The first outer layer, the first inner layer is ferric oxide, the first middle layer is a carbon layer, and the first outer layer is nano ferric oxide particles.
- 如权利要求3所述的方法，其中，所述缓冲剂为柠檬酸-柠檬酸钠。The method of claim 3, wherein the buffer is citric acid-sodium citrate.
- 如权利要求3所述的方法，其中，所述保护气体为氮气。The method of claim 3, wherein the shielding gas is nitrogen.
- 如权利要求5所述的方法，其中，重复步骤(4)-(7)，以制备具有多个组合层的电磁波吸收材料。The method according to claim 5, wherein steps (4)-(7) are repeated to prepare an electromagnetic wave absorbing material having a plurality of combined layers.
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