Iron-cobalt-nickel nanocrystalline / carbon fiber composite material and preparation method and application thereof

Abstract

The invention discloses an iron-cobalt-nickel nanocrystalline / carbon fiber composite material and a preparation method and application thereof, and belongs to the technical field of electromagnetic shielding material preparation. The main preparation method of the iron-cobalt-nickel nanocrystalline / carbon fiber composite material comprises the following steps: immersing activated carbon fiber cloth into a chemical plating solution, and carrying out chemical reaction to obtain the iron-cobalt-nickel nanocrystalline / carbon fiber composite material. According to the carbon fiber composite material, the carbon fiber cloth is mainly used as a base material, iron-cobalt-nickel nanocrystals are prepared on the surface of the carbon fiber cloth through a chemical plating method, and finally the iron-cobalt-nickel nanocrystal / carbon fiber composite material is obtained and has excellent electromagnetic shielding performance.

Description

Technical Field

[0001] The invention relates to the technical field of electromagnetic shielding material preparation, and in particular to an iron-cobalt-nickel nanocrystalline / carbon fiber composite material and a preparation method and application thereof. Background Art

[0002] With the development of modern communication technology and intelligent products and equipment, electromagnetic waves are used as a carrier of information transmission in daily life, military activities and scientific research, and electromagnetic waves provide convenience for work and life. At present, the main way to reduce the negative impact of electromagnetic waves is to use electromagnetic shielding materials to block the propagation path of electromagnetic waves and minimize interference and radiation to the protected target. Therefore, electromagnetic shielding materials will usher in unprecedented new opportunities and become a key component of electronic materials and even future new materials.

[0003] Carbon fiber is widely used in electromagnetic shielding. Carbon fiber materials have good electrical conductivity and electromagnetic shielding properties, and can effectively absorb and scatter electromagnetic waves, thereby reducing the propagation and reflection of electromagnetic waves. This makes carbon fiber an ideal choice for making electromagnetic shielding materials. However, when only carbon fiber is used as a shielding material, there may be defects such as low magnetic permeability, high dielectric constant and narrow absorption band.

[0004] In the prior art, there are related patents that treat the surface of carbon fiber with a metal layer to improve the mechanical properties of the carbon fiber, such as CN106801335A; or reduce the resistivity by coating the surface of carbon fiber fabric with metal, such as CN112144272A and CN107164950A. In the prior art, the metal materials coated on the surface of carbon fiber are mostly copper, nickel and other materials, and there is little research on the electromagnetic shielding performance of carbon fiber materials coated with multiple metals. Summary of the invention

[0005] In order to solve the problems existing in the prior art, the present invention provides an iron-cobalt-nickel nanocrystal / carbon fiber composite material and a preparation method and application thereof; the present invention adopts a chemical plating method to in-situ modify soft magnetic cobalt-nickel nanocrystals on carbon fibers to enhance the electromagnetic interference shielding performance of the carbon fibers, and the modified carbon fibers not only retain their original light weight and high strength characteristics, but also significantly improve their electrical conductivity by introducing metal alloy components, thereby further optimizing the electromagnetic shielding performance.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: In one aspect, the present invention provides a method for preparing an iron-cobalt-nickel nanocrystal / carbon fiber composite material, comprising: (1) Pretreatment of carbon fiber cloth; (2) performing roughening, sensitization and activation treatments on the pretreated carbon fiber cloth in sequence to obtain an activated carbon fiber cloth; (3) immersing the activated carbon fiber cloth in a chemical plating solution at a reaction temperature of 85° C. for a reaction time of 60 min to obtain an iron-cobalt-nickel nanocrystal / carbon fiber composite material; The chemical plating solution is prepared by the following method: dissolving dimethylamino borane, potassium sodium tartrate, sodium citrate, phosphorous acid, ammonium sulfate and metal sulfate heptahydrate in deionized water, and adjusting the pH of the chemical plating solution to 4.0-8.0 using sodium hydroxide; The addition amount of the dimethylamino borane is 0.2-0.5 mol / L, the addition amount of the potassium sodium tartrate is 0.1-1.0 mol / L, the addition amount of the sodium citrate is 0.01-0.1 mol / L, the addition amount of the 0.05 mol sodium citrate and the phosphorous acid is 0.01-0.1 mol / L, the addition amount of the ammonium sulfate is 0.1-0.5 mol / L, the addition amount of the metal sulfate heptahydrate is 0.02-0.15 mol / L, the metal ions in the metal sulfate heptahydrate are iron, cobalt and nickel; the molar ratio of the iron, cobalt and nickel is 10-25:50-70:5-40.

[0007] Furthermore, the step (1) specifically includes: cutting the carbon fiber cloth into a shape of 10 × 10 cm, and sealing the edges of the carbon fiber cloth with a sewing machine to prevent deformation of the carbon fiber during processing.

[0008] Furthermore, in step (2), the specific roughening process is as follows: the pretreated carbon fiber is placed in a 65wt% concentrated nitric acid solution and ultrasonically vibrated for 1 hour, then taken out, washed with deionized water until the pH value reaches neutral, and dried at room temperature.

[0009] Furthermore, in the step (2), the specific sensitization treatment process is: putting the roughened carbon fiber cloth into the sensitization plating solution, soaking for half an hour, taking it out and cleaning it with deionized water, and drying it at room temperature; the ratio of the sensitization plating solution is: SnCl2, 20 g / L; 37wt% HCl, 40 mL / L; the rest is deionized water.

[0010] Furthermore, in step (2), the specific activation treatment process is: placing the sensitized carbon fiber into an activation plating solution, soaking for half an hour, taking it out and cleaning it with deionized water, and drying it at room temperature; the activation plating solution ratio is: PdCl2, 0.2 g / L; 37wt% HCl, 5mL / L; the rest is deionized water.

[0011] Preferably, in step (3), the amount of dimethylamino borane added is 0.26 mol / L, the amount of potassium sodium tartrate added is 0.2 mol / L, the amount of sodium citrate added is 0.05 mol / L, the amount of phosphorous acid added is 0.05 mol / L, the amount of ammonium sulfate added is 0.2 mol / L, and the amount of metal sulfate heptahydrate added is 0.07 mol / L.

[0012] Preferably, the metal sulfate heptahydrate is a mixture of ferrous sulfate heptahydrate, cobalt sulfate heptahydrate and nickel sulfate heptahydrate.

[0013] On the other hand, the present invention also provides an iron-cobalt-nickel nanocrystal / carbon fiber composite material prepared by the above method.

[0014] On the other hand, the present invention also provides an application of the above-mentioned iron-cobalt-nickel nanocrystal / carbon fiber composite material in the field of electromagnetic shielding technology.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention adopts chemical plating to in-situ modify soft magnetic cobalt-nickel nanocrystals on carbon fiber to enhance the electromagnetic interference shielding performance of carbon fiber. The modified carbon fiber not only retains its original light weight and high strength characteristics, but also significantly improves its electrical conductivity by introducing metal alloy components, which is the key to achieving efficient electromagnetic shielding and further optimizes the electromagnetic shielding performance. The carbon fiber composite material of the present invention mainly uses carbon fiber cloth as the substrate, and iron-cobalt-nickel nanocrystals are prepared on its surface by chemical plating method, and finally obtains iron-cobalt-nickel nanocrystal / carbon fiber composite material. Its main preparation method is: immersing the activated carbon fiber cloth into a chemical plating solution, and obtaining the iron-cobalt-nickel nanocrystal / carbon fiber composite material through chemical reaction. The iron-cobalt-nickel nanocrystal / carbon fiber composite material obtained by the present invention has excellent electromagnetic shielding performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The SEM images of Example 1 and Comparative Examples 1-4 are shown below; Figure 2 XRD diagrams of Example 1 and Comparative Examples 1-4 Figure 3 The resistance and conductivity diagrams of Example 1 and Comparative Examples 1-4; Figure 4 It is a comparison chart of electromagnetic shielding performance of Example 1 and Comparative Examples 2-4; Figure 5 SEM images of Example 1, Comparative Example 1 and Comparative Examples 5-6; Figure 6 The XRD patterns of Example 1, Comparative Example 1 and Comparative Examples 5-6 are shown; Figure 7 The resistance and conductivity diagrams of Example 1 and Comparative Examples 5-6; Figure 8 It is a comparison chart of the electromagnetic shielding performance of Example 1 and Comparative Examples 5-6. DETAILED DESCRIPTION

[0017] In order to make the technical problems to be solved, technical solutions and advantages of the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0018] In the present invention, the materials and reagents used can be obtained from commercial sources unless otherwise specified.

[0019] The present invention provides an iron-cobalt-nickel nanocrystal / carbon fiber composite material and a preparation method and application thereof. Specific embodiments are as follows.

[0020] Example 1 A method for preparing an iron-cobalt-nickel nanocrystal / carbon fiber composite material, comprising: (1) Cut the carbon fiber cloth into a shape of 10 × 10 cm and seal the edges of the carbon fiber cloth with a sewing machine to prevent deformation of the carbon fiber during processing; (2) Place the carbon fiber cloth in an acetone solution and ultrasonically vibrate for 1 hour. Take it out and wash it with deionized water and dry it at room temperature. Roughening: put the carbon fiber cloth into a 65wt% concentrated nitric acid solution and ultrasonically vibrate for 1 hour, then take it out, wash it with deionized water until the pH value reaches neutral, and dry it at room temperature; Sensitization: put the roughened carbon fiber cloth into the sensitization plating solution, soak for half an hour, take it out and clean it with deionized water, and dry it at room temperature; the ratio of the sensitization plating solution is: SnCl2, 20 g / L; 37wt% HCl, 40 mL / L; the rest is deionized water; Activation: Put the sensitized carbon fiber cloth into the activation plating solution, soak for half an hour, take it out and clean it with deionized water, and dry it at room temperature; the ratio of the activation plating solution is: PdCl2, 0.2 g / L; 37wt% HCl, 5mL / L; the rest is deionized water, and the activated carbon fiber cloth is obtained.

[0021] (3) immersing the activated carbon fiber cloth in a chemical plating solution, wherein the formula of the chemical plating solution is as follows: dissolving 0.26 M dimethylaminoborane, 0.2 M sodium tartrate, 0.05 M sodium citrate, 0.05 M phosphorous acid, 0.2 M ammonium sulfate and 0.07 M metal sulfate heptahydrate in 1 L of deionized water; adjusting the pH of the plating solution to 6.0 with 1 M NaOH; The metal sulfate heptahydrate is a mixture of ferrous sulfate heptahydrate, cobalt sulfate heptahydrate and nickel sulfate heptahydrate in a molar ratio of 23:67:10.

[0022] (4) At a chemical plating temperature of 85 °C, the carbon fiber cloth was immersed in the chemical plating solution for 60 min to obtain an iron-cobalt-nickel / carbon fiber composite material.

[0023] In order to further illustrate the beneficial effects of the present invention, the following comparative example was constructed.

[0024] Comparative Example 1 The unreacted original carbon fiber cloth was used as Comparative Example 1.

[0025] Comparative Example 2 In this comparative example, the chemical plating time in step (4) is 30 min, and the other conditions are the same as those in Example 1.

[0026] Comparative Example 3 In this comparative example, the chemical plating time in step (4) is 90 min, and the other conditions are the same as those in Example 1.

[0027] Comparative Example 4 In this comparative example, the chemical plating time in step (4) is 120 min, and the other conditions are the same as those in Example 1.

[0028] Comparative Example 5 In this comparative example, the chemical plating temperature in step (4) is 45°C, and the other conditions are the same as those in Example 1.

[0029] Comparative Example 6 In this comparative example, the chemical plating temperature in step (4) is 65° C., and the other conditions are the same as those in Example 1. The materials prepared in the above examples and comparative examples were tested, and the results are as follows.

[0030] The morphology and microstructure of the surface fibers of the carbon fiber cloth of Example 1 and Comparative Examples 1-4 are as follows: Figure 1 As shown. Figure 1 It can be seen that as the chemical plating time increases, iron-cobalt-nickel nanocrystals are gradually formed on the surface of the carbon fiber cloth, and the grain size gradually increases. The surface morphology of the iron-cobalt-nickel nanocrystal / carbon fiber composite material of Comparative Example 2 shows that the iron-cobalt-nickel nanocrystals have not been fully formed. In contrast, the iron-cobalt-nickel layer in the iron-cobalt-nickel nanocrystal / carbon fiber composite material of Example 1 is uniformly deposited on the surface of the carbon fiber. Prolonging the reaction time may promote the aggregation and crystallization of metal atoms on the surface of the carbon fiber, resulting in an increase in the size of the iron-cobalt-nickel nanocrystals. Large alloy particles can be clearly found in the iron-cobalt-nickel nanocrystal / carbon fiber composite materials of Comparative Examples 3 and 4. Figure 2 The XRD patterns of Example 1 and Comparative Examples 1-4 are shown in Table 1, wherein Comparative Example 1 is 0 h. Figure 2 It can be seen that with the increase of chemical plating time, the diffraction peaks of FeCoNi nanocrystals become more obvious, and due to the neat arrangement of particles, the crystallinity increases with the increase of chemical plating thickness. Figure 3 The resistance and conductivity diagrams of Example 1 and Comparative Examples 1-4 are shown in Figure 1. Compared with Comparative Example 1, the resistance of Example 1 and Comparative Examples 2-4 is lower and the conductivity is higher. Among them, the conductivity of Example 1 is the highest, which is mainly due to the fact that the thickness and particle size of the FeCoNi nanocrystals have an important influence on the conductive properties of the carbon fiber. Thicker FeCoNi nanocrystals or larger FeCoNi nanocrystals may cause the conductive properties of the carbon fiber to decrease. The present invention also uses a coaxial method to test the electromagnetic shielding properties of the material using a vector network analyzer, such as Figure 4 As shown, it is a comparison chart of the electromagnetic shielding performance of Example 1 and Comparative Examples 2-4. As the electroless plating time increases, the electromagnetic shielding effectiveness of the iron-cobalt-nickel / carbon fiber composite material shows a trend of first increasing and then decreasing, among which the electromagnetic shielding effectiveness of Example 1 is the best, indicating that the presence of iron-cobalt-nickel nanocrystals on the surface of the carbon fiber cloth can enhance the electromagnetic shielding effectiveness of the carbon fiber composite material. However, for Comparative Examples 3 and 4, their electromagnetic shielding effectiveness gradually decreases, which means that there is a threshold value of metal content in the electromagnetic shielding effectiveness.

[0031] The morphology and microstructure of Example 1, Comparative Example 1, and Comparative Examples 5-6 are as follows: Figure 5 As shown. Figure 5 It can be seen that there are few iron-cobalt-nickel nanocrystals attached to the surface of the carbon fiber in Comparative Example 5. As the chemical plating temperature increases, iron-cobalt-nickel nanocrystals on the surface of the fabric gradually form, and the grain size also increases. The higher the temperature, the better the effect of chemical plating, and the metal surface morphology formed on the surface of the iron-cobalt-nickel / carbon fiber composite material is the best. Figure 6 The XRD patterns of Example 1, Comparative Examples 5-6 and Comparative Example 1 (25°C) are shown in Table 1. Figure 6 It can be seen that as the chemical plating temperature increases, the structural peak of the Fe-Co-Ni nanocrystal becomes more obvious, and the crystallinity gradually increases. No diffraction peak of C is observed in Comparative Examples 5 and 6, indicating that the Fe-Co-Ni nanocrystal is completely loaded on the surface of the carbon fiber. Figure 7 The resistance and conductivity diagrams of Example 1 and Comparative Examples 5-6 show that, compared with Comparative Example 1, the conductivity of the composite materials of Example 1 and Comparative Examples 5-6 are significantly increased, indicating that the higher the temperature, the higher the conductivity of the iron-cobalt-nickel nanocrystal / carbon fiber composite material. Figure 8 The electromagnetic shielding effectiveness of Example 1 and Comparative Examples 5-6. As the temperature increases, the electromagnetic shielding effectiveness of the Fe-Co-Ni nanocrystal / carbon fiber composite material gradually increases.

[0032] The conductivity data of the above-mentioned Example 1 and Comparative Examples 1-6 and the electromagnetic shielding effectiveness data at 2-16 GHz are shown in Table 1:

[0033] It can be seen from Table 1 that the composite materials prepared under the specific chemical plating time and temperature of the present invention have higher electrical conductivity, which is one order of magnitude higher than that of comparative examples 1-6; at the same time, they have good electromagnetic shielding effectiveness at 2-16 GHz. The composite materials prepared in comparative examples 1-6 have the problem of poor high-frequency shielding effectiveness or poor low-frequency shielding effectiveness.

[0034] The inventors have also optimized the ratio of metal sulfates in the chemical plating solution, as described in detail below.

[0035] Comparative Example 7 In this comparative example, ferrous sulfate heptahydrate and cobalt sulfate heptahydrate were replaced by an equimolar amount of nickel sulfate heptahydrate; the other conditions were the same as those in Example 1.

[0036] Comparative Example 8 In this comparative example, ferrous sulfate heptahydrate and nickel sulfate heptahydrate were replaced by an equimolar amount of cobalt sulfate heptahydrate; the other conditions were the same as those in Example 1.

[0037] Comparative Example 9 In this comparative example, cobalt sulfate heptahydrate and nickel sulfate heptahydrate were replaced by ferrous sulfate heptahydrate in an equal molar amount; the other conditions were the same as those in Example 1.

[0038] Comparative Example 10 In this comparative example, the metal sulfate heptahydrate is a mixture of cobalt sulfate heptahydrate and nickel sulfate heptahydrate in a molar ratio of 1:1; the other conditions are the same as those in Example 1.

[0039] Comparative Example 11 In this comparative example, the metal sulfate heptahydrate is a mixture of ferrous sulfate heptahydrate and nickel sulfate heptahydrate in a molar ratio of 1:1, and the other conditions are the same as those in Example 1.

[0040] Comparative Example 12 In this comparative example, the metal sulfate heptahydrate is a mixture of ferrous sulfate heptahydrate and cobalt sulfate heptahydrate in a molar ratio of 1:1, and the other conditions are the same as those in Example 1.

[0041] Comparative Example 13 In this comparative example, cobalt sulfate heptahydrate was replaced by an equimolar amount of copper sulfate pentahydrate, and the other conditions were the same as in Example 1.

[0042] Comparative Example 14 In this comparative example, the metal sulfate heptahydrate is a mixture of ferrous sulfate heptahydrate, cobalt sulfate heptahydrate, and nickel sulfate heptahydrate in a molar ratio of 1:1:1, and the other conditions are the same as those in Example 1.

[0043] Comparative Example 15 In this comparative example, the metal sulfate heptahydrate is a mixture of ferrous sulfate heptahydrate, cobalt sulfate heptahydrate, and nickel sulfate heptahydrate in a molar ratio of 67:10:23, and the other conditions are the same as those in Example 1.

[0044] Comparative Example 16 In this comparative example, the metal sulfate heptahydrate is a mixture of ferrous sulfate heptahydrate, cobalt sulfate heptahydrate, and nickel sulfate heptahydrate in a molar ratio of 1:2:1, and the other conditions are the same as those in Example 1.

[0045] The performance of comparative examples 7-16 was tested, and the results are shown in Table 2:

[0046] It can be seen from Table 2 that by adjusting the types of metal sulfates in the chemical plating solution and the ratio of the three, the electrical conductivity and electromagnetic shielding effectiveness of the obtained composite material are worse than those of Example 1.

[0047] In summary, the present invention obtains an iron-cobalt-nickel nanocrystal / carbon fiber composite material with higher electrical conductivity and better electromagnetic shielding performance by specifically selecting metal sulfate in the chemical plating solution in coordination with specific process conditions.

[0048] The above is a preferred embodiment of the present invention. For ordinary technicians in this technical field, making several improvements and modifications without departing from the principles of the present invention should also be regarded as within the protection scope of the present invention.

Claims

1. A method for preparing an iron-cobalt-nickel nanocrystal / carbon fiber composite material, characterized in that: include: (1) Pretreatment of carbon fiber cloth; (2) performing roughening, sensitization and activation treatments on the pretreated carbon fiber cloth in sequence to obtain an activated carbon fiber cloth; (3) immersing the activated carbon fiber cloth in a chemical plating solution at a reaction temperature of 85°C and a reaction time of 60 min to obtain an iron-cobalt-nickel nanocrystal / carbon fiber composite material; The chemical plating solution is prepared by the following method: dissolving dimethylamino borane, potassium sodium tartrate, sodium citrate, phosphorous acid, ammonium sulfate and metal sulfate heptahydrate in deionized water, and adjusting the pH of the chemical plating solution to 4.0-8.0 using sodium hydroxide; The addition amount of the dimethylamino borane is 0.2-0.5 mol / L, the addition amount of the potassium sodium tartrate is 0.1-1.0 mol / L, the addition amount of the sodium citrate is 0.01-0.1 mol / L, the addition amount of the 0.05 mol sodium citrate and the phosphorous acid is 0.01-0.1 mol / L, the addition amount of the ammonium sulfate is 0.1-0.5 mol / L, the addition amount of the metal sulfate heptahydrate is 0.02-0.15 mol / L, the metal ions in the metal sulfate heptahydrate are iron, cobalt and nickel; the molar ratio of the iron, cobalt and nickel is 10-25:50-70:5-40.

2. The method according to claim 1, characterized in that The step (1) specifically includes: cutting the carbon fiber cloth into a shape of 10×10 cm, and sealing the edges of the carbon fiber cloth with a sewing machine to prevent deformation of the carbon fiber during processing.

3. The method according to claim 2, characterized in that In the step (2), the specific roughening treatment process is: put the carbon fiber cloth into a 65wt% concentrated nitric acid solution and ultrasonically vibrate for 1 hour, then take it out, wash it with deionized water until the pH value reaches neutral, and dry it at room temperature.

4. The method according to claim 3, characterized in that In the step (2), the specific sensitization treatment process is: put the roughened carbon fiber cloth into the sensitization plating solution, soak for half an hour, take it out and clean it with deionized water, and dry it at room temperature; the sensitization plating solution has the following ratios: SnCl2, 20 g / L; 37wt% HCl, 40 mL / L; the rest is deionized water.

5. The method according to claim 4, characterized in that In the step (2), the specific activation treatment process is: putting the sensitized carbon fiber cloth into the activation plating solution, soaking for half an hour, taking it out and cleaning it with deionized water, and drying it at room temperature; the activation plating solution ratio is: PdCl2, 2 g / L; 37wt% HCl, 5mL / L; the rest is deionized water.

6. The method according to claim 5, characterized in that In the step (3), the amount of dimethylamino borane added is 0.26 mol / L, the amount of potassium sodium tartrate added is 0.2 mol / L, the amount of sodium citrate added is 0.05 mol / L, the amount of phosphorous acid added is 0.05 mol / L, the amount of ammonium sulfate added is 0.2 mol / L, and the amount of metal sulfate heptahydrate added is 0.07 mol / L.

7. The method according to claim 6, characterized in that The metal sulfate heptahydrate is a mixture of ferrous sulfate heptahydrate, cobalt sulfate heptahydrate and nickel sulfate heptahydrate.

8. An iron-cobalt-nickel nanocrystal / carbon fiber composite material, characterized in that: It is prepared by the method according to any one of claims 1 to 7.

9. Application of the iron-cobalt-nickel nanocrystal / carbon fiber composite material according to claim 8 in the field of electromagnetic shielding technology.

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