Method for preparing light magnetic carbon composite electromagnetic compatibility material by inducing chelate salt through carbon nitride

Abstract

The invention belongs to the technical field of electromagnetic compatibility, and discloses a method for preparing a light magnetic carbon composite electromagnetic compatibility material by inducing chelate salt through carbon nitride, which comprises the following steps: 1, fully dispersing metal chelate salt and graphitized carbon nitride to form a uniform mixture; and 2, carrying out temperature programming calcination treatment on the uniform mixture to obtain the target magnetic carbon composite material. According to the present invention, the construction of the rich porous structure is achieved, the preparation process is simple and environmentally friendly, the template method adopted for the conventional porous structure inevitably comprises the introduction and the removal of the template agent in the whole production process, the use of the acid, the alkali or the oxidizing agent is involved, and the harm and the pollution are serious; the adopted carbon nitride template can be decomposed in the high-temperature pore-forming process for preparing the wave-absorbing agent, so that the problem of subsequent template removal is avoided.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electromagnetic compatibility and relates to a method for preparing a light magnetic carbon composite electromagnetic compatibility material from a carbon nitride-induced chelate salt. BACKGROUND

[0002] In recent years, electronic devices in the GHz range are widely used, making electromagnetic pollution a common problem that has caused great harm to human health and threatened information security and national defense security. At present, electromagnetic absorption is the main strategy to solve this problem, which dissipates electromagnetic energy through multiple attenuation mechanisms inside the wave-absorbing agent to avoid secondary pollution. Ideal wave-absorbing materials have the characteristics of thin thickness, light weight, wide effective absorption bandwidth, and strong absorption capacity, but traditional microwave absorbing materials (such as magnetic metals, ferrites, ceramics, barium titanate, etc.) have certain absorption performance, but generally have application bottlenecks such as high filling degree and narrow effective absorption bandwidth. Therefore, how to achieve excellent electromagnetic wave absorption at low filling amount is still a challenge.

[0003] Carbon materials are considered to have great potential in the wave-absorbing field due to their advantages of abundant resources, low density, good electrical conductivity, high dielectric loss, and good stability. Introducing heteroatoms into the carbon skeleton can induce dipole relaxation loss, thereby enhancing electromagnetic dissipation capacity. However, for single-component carbon materials, impedance mismatch caused by excessively high electrical conductivity and lack of magnetic loss capacity can greatly limit their wave-absorbing performance. According to the effective medium theory, constructing a cross-linked porous structure can reduce the density and filling ratio, and multiple reflections and interface polarization at the air-carbon interface can also enhance the dissipation capacity of the material to microwave energy. In addition, the interconnected network structure can also promote electron transfer and transition, thereby enhancing the electrical conduction loss. Today, the construction of porous morphology involves the introduction and removal of templates, and the preparation method is complex and environmentally unfriendly. On the other hand, introducing magnetic elements can enhance magnetic attenuation capacity and improve impedance characteristics, but effective control of the size of doped magnetic nanoparticles still faces challenges. When the size of the magnetic nanoparticles exceeds the skin depth, electromagnetic waves will be reflected, leading to poor impedance matching and being detrimental to attenuating electromagnetic energy. Reducing the size of the magnetic nanoparticles can not only form a large-area magnetic coupling attenuation network but also endow the material with light weight and rich interface polarization relaxation.

[0004] In summary, a simple and environmentally friendly preparation process for a magnetic carbon composite wave-absorbing material with effective porous structure and controllable magnetic particle size is proposed, which is a prerequisite for the application of light-weight and high-efficiency magnetic carbon composite wave-absorbing materials and will have broad application prospects and significant practical value. SUMMARY

[0005] (I) Invention purpose The application aims to provide a method for preparing light magnetic carbon composite electromagnetic compatibility materials by using carbon nitride induced chelate salt, to develop high-performance magnetic carbon composite wave-absorbing materials through a simple and green preparation process, and to achieve excellent electromagnetic compatibility effect.

[0006] The technical scheme To solve the above technical problems, the application provides a method for preparing light magnetic carbon composite electromagnetic compatibility materials by using carbon nitride induced chelate salt, characterized by comprising the following steps: Firstly, the metal chelate salt is uniformly dispersed with graphitized carbon nitride to form a uniform mixture; Secondly, the uniform mixture is subjected to programmed temperature calcination treatment to obtain the target magnetic carbon composite material.

[0007] Further, in the first step, the metal chelate salt is a commercially available metal chelate salt or is prepared by using an organic ligand and a metal salt.

[0008] Further, the commercially available metal salt is one of ferrocene, cobaltocene, nickelocene, acetylacetone iron, acetylacetone ferrous, acetylacetone cobalt, and acetylacetone nickel.

[0009] Further, the organic ligand includes terephthalic acid and triethylenediamine, and the metal salt is selected as a nickel salt as the metal salt to prepare a nickel metal chelate salt.

[0010] Further, 1 g of graphitized carbon nitride and 0.25 g of ferrocene are weighed as raw materials, the two are first uniformly mixed by using a stirrer, then the mixture is transferred to an alumina porcelain boat for programmed temperature treatment, under the protection of an argon atmosphere, heating to 800 o C at a heating rate of 5 o C / min and keeping for 2 h, then stopping heating and cooling to room temperature, and the collected black powder is the required magnetic carbon target product.

[0011] Further, 1 g of graphitized carbon nitride and 0.25 g of acetylacetone cobalt are weighed as raw materials, the two are first uniformly mixed by using a stirrer, then the mixture is transferred to an alumina porcelain boat for programmed temperature treatment, under the protection of an argon atmosphere, heating to 850 o C at a heating rate of 5 o C / min and keeping for 2 h, then stopping heating and cooling to room temperature, and the collected black powder is the required magnetic carbon target product.

[0012] Further, 1 g of graphitized carbon nitride and 0.25 g of acetylacetone nickel are weighed as raw materials, the two are first uniformly mixed by using a stirrer, then the mixture is transferred to an alumina porcelain boat for programmed temperature treatment, under the protection of an argon atmosphere, heating to 850 oheated to 850 o C and kept for 2 h, then stop heating and cool to room temperature, the collected black powder is the desired magnetic carbon target product.

[0013] Further, 1 g of graphitized carbon nitride and 0.24 g of iron acetylacetate were weighed as raw materials, first using a blender to mix the two uniformly. Then the mixture was transferred to an alumina porcelain boat for programmed temperature treatment, under the protection of argon atmosphere, heated to 850 o C / min heating rate to 850 o C and kept for 2 h, then stop heating and cool to room temperature, the collected black powder is the desired magnetic carbon target product.

[0014] Further, 1 g of graphitized carbon nitride and 0.24 g of iron acetylacetate were weighed as raw materials, first using a blender to mix the two uniformly. Then the mixture was transferred to an alumina porcelain boat for programmed temperature treatment, under the protection of argon atmosphere, heated to 850 o C / min heating rate to 850 o C and kept for 2 h, then stop heating and cool to room temperature, the collected black powder is the desired magnetic carbon target product.

[0015] Further, 1.36 g of terephthalic acid, 0.96 g of triethylene diamine, 0.44 g of nickel nitrate were dissolved in 200 mL of N, N-dimethylformamide solvent by magnetic stirring treatment, and then 2 g of graphitized carbon nitride was added to form a uniform mixed solution. After the dispersion was poured into a rotary evaporation flask to completely remove the solvent, the obtained solid powder was placed in a tube furnace filled with argon, heated to 900 o C / min heating rate to 900 o C and kept for 2 h, then stop heating and cool to room temperature, the collected black powder is the desired magnetic carbon target product.

[0016] (Three) beneficial effects The method for preparing light magnetic carbon composite electromagnetic compatibility material by carbon nitride induced chelate salt provided by the above technical scheme has the following beneficial effects: (1) The construction of a rich porous structure is achieved, and the preparation process is simple and environmentally friendly. The conventional porous structure into the template method inevitably includes the introduction and removal of the template agent, involving the use of acid, base or oxidizing agent, causing serious harm and pollution. The carbon nitride template used in the present application will decompose during the high-temperature pore preparation process of the wave absorber, avoiding the problem of subsequent template removal.

[0017] (2) The effective control of magnetic nanoparticles is realized, which is beneficial to the development of new lightweight and efficient wave-absorbing materials. The in-situ encapsulation effect of the internal pressure release of carbon nitride and chelate salt can effectively control the size of the magnetic nanoparticles, realize the effective combination of lightweight and heterogeneous components, and finally achieve the purpose of efficient attenuation of electromagnetic waves through dielectric-magnetic multiple loss coupling, which has excellent electromagnetic compatibility. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is an embodiment 1 schematic diagram of the carbon nitride induced chelate salt preparation of lightweight magnetic carbon composite electromagnetic compatibility material of the present application.

[0019] Figure 2 is an embodiment 2 schematic diagram of the carbon nitride induced chelate salt preparation of lightweight magnetic carbon composite electromagnetic compatibility material of the present application.

[0020] Figure 3 is an embodiment 3 schematic diagram of the carbon nitride induced chelate salt preparation of lightweight magnetic carbon composite electromagnetic compatibility material of the present application.

[0021] Figure 4 is an embodiment 4 schematic diagram of the carbon nitride induced chelate salt preparation of lightweight magnetic carbon composite electromagnetic compatibility material of the present application.

[0022] Figure 5 is an embodiment 5 schematic diagram of the carbon nitride induced chelate salt preparation of lightweight magnetic carbon composite electromagnetic compatibility material of the present application.

[0023] Figure 6 is an embodiment 6 schematic diagram of the carbon nitride induced chelate salt preparation of lightweight magnetic carbon composite electromagnetic compatibility material of the present application. DETAILED DESCRIPTION

[0024] In order to make the purpose, content and advantages of the present application more clear, the specific embodiments of the present application are described in further detail below in combination with the drawings and examples.

[0025] In the process flow of the method for preparing lightweight magnetic carbon composite electromagnetic compatibility material induced by carbon nitride and chelate salt proposed in the present application, the raw materials are simple, the operability is strong, and the use of strong acid, strong base and strong oxidant is not involved, and the method specifically comprises the following steps: Firstly, the metal chelate salt and graphitized carbon nitride are dispersed to form a uniform mixture.

[0026] Among them, the chelate salt raw material can be ferrocene, cobaltocene, nickelocene, acetylacetone iron, acetylacetone ferrous, acetylacetone cobalt, acetylacetone nickel and other metal chelate salts that can be directly purchased; or metal chelate salt prepared by using organic ligand and metal salt, for example, terephthalic acid, triethylenediamine as organic ligand, nickel salt as metal salt, nickel metal chelate salt can be obtained.

[0027] Second step, the uniform mixture is treated by programmed temperature calcination, and the target magnetic carbon composite material is obtained.

[0028] The working principle of the present application is as follows: carbon nitride will decompose to produce a large amount of nitrogen-containing gas during high-temperature treatment, which can effectively induce the formation of a three-dimensional conductive network and rich pore structure, the pressure from the internal gas can push away the nanoparticles, avoid the agglomeration of the magnetic components, and thus achieve good particle size control effect. The chelate salt raw material can provide a carbon source and a magnetic source, and the in-situ formed compact coating structure of magnetic core-carbon shell inhibits the growth of the magnetic particles, further controls the particle size, and at the same time, the nitrogen-containing gas from the carbon nitride also effectively dopes the nitrogen atoms in the carbon material. Therefore, the method for preparing the light magnetic carbon composite electromagnetic compatibility material by using carbon nitride-induced chelate salt according to the present application can achieve simple preparation of the magnetic carbon composite material, and the developed material has the potential for outstanding electromagnetic compatibility application under the synergistic action of the mechanisms of dipole polarization, interface polarization, electric conduction loss and magnetic loss.

[0029] Example 1: 1 g of graphitized carbon nitride and 0.25 g of ferrocene were weighed as raw materials, and the two were first mixed uniformly using a blender. Then the mixture was transferred to an alumina ceramic boat for programmed temperature treatment, and heated to 800 o C at a heating rate of 5 o C / min under the protection of argon atmosphere, and kept for 2 h, and then the heating was stopped and cooled to room temperature. The black powder collected was the target product of the magnetic carbon. The prepared magnetic carbon material presented a cross-linked sheet-like micro-morphology, had a rich porous structure, and the size of the loaded magnetic particles was well controlled. Finally, a high strong absorption of -56.1 dB and an effective bandwidth of 5.8 GHz were achieved at a low filling amount of 4 wt%, as shown in Figure 1 .

[0030] Example 2: 1 g of graphitized carbon nitride and 0.25 g of cobalt acetylacetonate were weighed as raw materials, and the two were first mixed uniformly using a blender. Then the mixture was transferred to an alumina ceramic boat for programmed temperature treatment, and heated to 850 o C at a heating rate of 5 o C / min under the protection of argon atmosphere, and kept for 2 h, and then the heating was stopped and cooled to room temperature. The black powder collected was the target product of the magnetic carbon. The prepared magnetic carbon material presented a cross-linked pipe-like micro-morphology, had a rich porous structure, and the size of the loaded magnetic particles was well controlled. Finally, a high strong absorption of -71.8 dB and an effective bandwidth of 6.2 GHz were achieved at a low filling amount of 6 wt%, as shown in Figure 2 .

[0031] Example 3: Take 1 g of graphitized carbon nitride and 0.25 g of nickel acetylacetonate as raw materials, first use a blender to mix the two evenly. Then transfer the mixture to an alumina porcelain boat for programmed temperature treatment, heat to 850 o C at a heating rate of 5 o C / min under the protection of argon atmosphere and keep for 2 h, then stop heating and cool to room temperature, the black powder collected is the desired magnetic carbon target product. The prepared magnetic carbon material presents a cross-linked tubular micro-morphology, with a rich porous structure and the size of the loaded magnetic particles is well controlled, finally realizes a high strong absorption of -52.6 dB and an effective bandwidth of 5.8 GHz at a low filling amount of 6 wt%, as shown in Figure 3 .

[0032] Example 4: Take 1 g of graphitized carbon nitride and 0.24 g of ferrous acetylacetonate as raw materials, first use a blender to mix the two evenly. Then transfer the mixture to an alumina porcelain boat for programmed temperature treatment, heat to 850 o C at a heating rate of 5 o C / min under the protection of argon atmosphere and keep for 2 h, then stop heating and cool to room temperature, the black powder collected is the desired magnetic carbon target product. The prepared magnetic carbon material presents a cross-linked sheet-like micro-morphology, with a rich porous structure and the size of the loaded magnetic particles is well controlled, finally realizes a high strong absorption of -54.1 dB and an effective bandwidth of 5.3 GHz at a low filling amount of 12 wt%, as shown in Figure 4 .

[0033] Example 5: Take 1 g of graphitized carbon nitride and 0.34 g of iron acetylacetonate as raw materials, first use a blender to mix the two evenly. Then transfer the mixture to an alumina porcelain boat for programmed temperature treatment, heat to 850 o C at a heating rate of 5 o C / min under the protection of argon atmosphere and keep for 2 h, then stop heating and cool to room temperature, the black powder collected is the desired magnetic carbon target product. The prepared magnetic carbon material presents a cross-linked sheet-like micro-morphology, with a rich porous structure and the size of the loaded magnetic particles is well controlled, finally realizes a high strong absorption of -65.5 dB and an effective bandwidth of 5.3 GHz at a low filling amount of 9 wt%, as shown in Figure 5 .

[0034] Example 6: 1.36 g of terephthalic acid, 0.96 g of triethylenediamine, and 0.44 g of nickel nitrate were dissolved in 200 mL of N,N-dimethylformamide solvent by magnetic stirring. Then, 2 g of graphitized carbon nitride was added to form a homogeneous mixed solution. After the dispersion was completely removed by rotary evaporation in a flask, the resulting solid powder was placed in a tube furnace filled with argon gas and heated at 5... o Heating to 900°C / min at a heating rate o Heating was carried out at C for 2 hours, then the mixture was stopped and cooled to room temperature. The collected black powder was the desired magnetic carbon target product. The prepared magnetic carbon material exhibited a cross-linked sheet-like microstructure with abundant porous structure and well-controlled magnetic particle size. Ultimately, with a low filling amount of 5 wt%, a high absorption of -72.3 dB and an effective bandwidth of 5.4 GHz were achieved. Figure 6 As shown.

[0035] In summary, the method for preparing lightweight magnetic carbon composite electromagnetic compatibility materials by carbon nitride-induced chelate salt proposed in this invention can guide the research and development of novel magnetic carbon composite microwave absorbing materials with low dosage and high performance, and has broad application prospects in the field of electromagnetic compatibility.

[0036] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing lightweight magnetic carbon composite electromagnetic compatibility materials using carbon nitride-induced chelating salts, characterized in that, Includes the following steps: The first step is to fully disperse the metal chelate salt and graphitized carbon nitride to form a homogeneous mixture; The second step involves calcining the homogeneous mixture at a programmed temperature to obtain the target magnetic carbon composite material.

2. The method for preparing lightweight magnetic carbon composite electromagnetic compatibility materials by carbon nitride-induced chelation salt as described in claim 1, characterized in that, In the first step, the metal chelate salt is a commercially available metal chelate salt, or it can be prepared by using organic ligands and metal salts.

3. The method for preparing lightweight magnetic carbon composite electromagnetic compatibility materials by carbon nitride-induced chelation salt as described in claim 2, characterized in that, Commercially available metal salts are one of the following: ferrocene, cobalt calorimetry, nickel calorimetry, ferric acetylacetone, ferrous acetamide acetone, cobalt acetylacetone, and nickel acetylacetone.

4. The method for preparing lightweight magnetic carbon composite electromagnetic compatibility materials by carbon nitride-induced chelation salt as described in claim 3, characterized in that, The organic ligands include terephthalic acid and triethylenediamine, and nickel salt is selected as the metal salt to prepare nickel metal chelate salt.

5. The method for preparing lightweight magnetic carbon composite electromagnetic compatibility materials by carbon nitride-induced chelation salt as described in claim 4, characterized in that, Weigh 1 g of graphitized carbon nitride and 0.25 g of ferrocene as raw materials. First, mix the two evenly using a mixer. Then, transfer the mixture to an alumina ceramic boat for programmed temperature treatment under an argon protective atmosphere at 5°C. o Heating to 800°C / min at a heating rate o Heat at C for 2 hours, then stop heating and cool to room temperature. The collected black powder is the desired magnetic carbon target product.

6. The method for preparing lightweight magnetic carbon composite electromagnetic compatibility materials by carbon nitride-induced chelation salt as described in claim 4, characterized in that, Weigh 1 g of graphitized carbon nitride and 0.25 g of cobalt acetylacetonate as raw materials. First, mix the two evenly using a mixer. Then, transfer the mixture to an alumina ceramic boat for programmed temperature treatment under an argon protective atmosphere at 5°C. o Heating to 850°C at a heating rate of C / min o Heat at C for 2 hours, then stop heating and cool to room temperature. The collected black powder is the desired magnetic carbon target product.

7. The method for preparing lightweight magnetic carbon composite electromagnetic compatibility materials by carbon nitride-induced chelation salt as described in claim 4, characterized in that, Weigh 1 g of graphitized carbon nitride and 0.25 g of nickel acetylacetonate as raw materials, and first mix them thoroughly using a mixer. Then transfer the mixture to an alumina ceramic boat for programmed temperature treatment under an argon protective atmosphere at 5°C. o Heating to 850°C at a heating rate of C / min o Heat at C for 2 hours, then stop heating and cool to room temperature. The collected black powder is the desired magnetic carbon target product.

8. The method for preparing lightweight magnetic carbon composite electromagnetic compatibility materials using carbon nitride-induced chelate salts as described in claim 4, characterized in that, Weigh 1 g of graphitized carbon nitride and 0.24 g of ferrous acetylacetone as raw materials, and first mix them thoroughly using a mixer. Then transfer the mixture to an alumina ceramic boat for programmed temperature treatment under an argon protective atmosphere at 5°C. o Heating to 850°C at a heating rate of C / min o Heat at C for 2 hours, then stop heating and cool to room temperature. The collected black powder is the desired magnetic carbon target product.

9. The method for preparing lightweight magnetic carbon composite electromagnetic compatibility materials by carbon nitride-induced chelation salt as described in claim 4, characterized in that, Weigh 1 g of graphitized carbon nitride and 0.34 g of ferric acetylacetone as raw materials, and first mix them thoroughly using a mixer. Then transfer the mixture to an alumina ceramic boat for programmed temperature treatment under an argon protective atmosphere at 5°C. o Heating to 850°C at a heating rate of C / min o Heat at C for 2 hours, then stop heating and cool to room temperature. The collected black powder is the desired magnetic carbon target product.

10. The method for preparing lightweight magnetic carbon composite electromagnetic compatibility materials by carbon nitride-induced chelation salt as described in claim 4, characterized in that, 1.36 g of terephthalic acid, 0.96 g of triethylenediamine, and 0.44 g of nickel nitrate were dissolved in 200 mL of N,N-dimethylformamide solvent using magnetic stirring. Then, 2 g of graphitized carbon nitride was added to form a homogeneous mixture. After completely removing the solvent by pouring the dispersion into a rotary evaporator flask, the resulting solid powder was placed in a tube furnace filled with argon gas and heated at 5... o Heating to 900°C / min at a heating rate o Heat at C for 2 hours, then stop heating and cool to room temperature. The collected black powder is the desired magnetic carbon target product.

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