A biomass-based FeS particle composite fiber and a preparation method thereof and an electromagnetic absorption material

Abstract

The present invention relates to the technical field of carbon fiber materials and composite material preparation thereof, specifically a biomass-based FeS particle composite fiber and a preparation method thereof and an electromagnetic absorption material. The biomass-based FeS particle composite fiber provided by the present invention comprises a hollow carbon fiber and FeS composited on the carbon fiber; the hollow carbon fiber is a carbide of tree cotton fiber. The composite fiber provided by the present invention is prepared by selecting biomass fibers with unique hollow morphology and performing carbonization treatment to obtain hollow carbon tube fibers, and then combining hydrothermal reaction to perform carbon tube-based magnetic particle composite materials. The composite fiber prepared by the present invention is prepared using tree cotton carbon-based materials with high hollowness and light weight. The preparation method is simple and the process is easy to control. The economic value of tree cotton biomass fibers is improved while giving them functional applications, and they show specificity in chemical and physical (thermal, optical, electromagnetic, etc.) properties.

Description

Technical Field

[0001] The invention relates to the technical field of carbon fiber materials and composite material preparation thereof, in particular to a biomass-based FeS particle composite fiber and a preparation method thereof, and an electromagnetic absorption material. Background Art

[0002] As a new multifunctional fiber material, carbon fiber is currently in great demand and widely used. It has good mechanical, thermal and electrical properties and can show specificity in chemical and physical (thermal, optical, electromagnetic, etc.) properties. The development of lightweight carbon fiber materials will enhance its multifunctionality.

[0003] The preparation method of the unique hollow morphology carbon material is complicated and costly, and the prior art products do not have hollow carbon tube materials derived from biomass materials and then composited with magnetic particles to prepare hollow carbon tube / flower-shaped FeS particle composite fibers.

[0004] Tree cotton is a wild plant shrub fiber species found accidentally on the edge of the primitive forest in Yunnan. The fruit of the ox-horned melon is deseeded and produced by pappus fiber. It is the second plant fiber that is 100% produced at one time after cotton, which has been the only plant fiber in the world for thousands of years. Tree cotton has its own excellent characteristics far exceeding cotton. Its fiber length: 31mm~35mm, fiber fineness: 16μm~28μm. The hollowness of Chinese tree cotton fiber is about 85%-90%, and its specific gravity is one-fourth of cotton fiber, which can be suspended and float in the air. Tree cotton fiber is a new type of hollow fiber that cannot be replicated or replaced by humans at present. Its unique ultra-high aspect ratio makes it easier to form a continuous conductive network in the matrix, which is of great significance for the development of lightweight carbon fiber materials. Summary of the invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide a biomass-based FeS particle composite fiber and a preparation method thereof and an electromagnetic absorption material. The preparation method provided by the present invention can obtain a biomass-based FeS particle composite fiber with high hollowness and light weight. The preparation method is simple and the process is easy to control. The prepared composite fiber shows specificity in chemical and physical (thermal, optical, electromagnetic, etc.) properties.

[0006] The invention provides a biomass-based FeS particle composite fiber, comprising a hollow carbon fiber and FeS composited on the carbon fiber; the hollow carbon fiber is a carbide of tree cotton fiber.

[0007] The composite fiber of the present invention includes hollow carbon fibers. Specifically, the hollow carbon fibers of the present invention are carbides of tree cotton fibers; the hollowness of the hollow carbon fibers is 85% to 90%; the fiber diameter of the hollow carbon fibers is 10 μm to 15 μm; and the carbon wall thickness of the hollow carbon fibers is 500 nm to 1000 nm.

[0008] Tree cotton is the pappus fiber produced by the fruit of the wild plant shrub fiber species, the ox-horned melon, which was accidentally discovered on the edge of the primitive forest in Yunnan. It is the second plant fiber that has been produced 100% at one time after cotton, which has been the only plant fiber in the world for thousands of years. Tree cotton has its own excellent properties far exceeding cotton, with high hollowness; its specific gravity is one-fourth of cotton fiber, and it can float in the air. Tree cotton fiber can be used as a biomass template for subsequent carbonization to obtain hollow carbon tube fiber. During the carbonization process, the tree cotton fiber including cellulose, hemicellulose, lignin, wax and a small amount of ash will be cracked during the high-temperature carbonization process to generate single carbon material. In some embodiments of the present invention, the hollowness of the tree cotton fiber is 85% to 90%; the fiber length of the tree cotton fiber is 31mm to 35mm; the fiber fineness of the tree cotton fiber, that is, the fiber diameter or cross-sectional area, is 16μm to 28μm.

[0009] The composite fiber of the present invention further comprises FeS compounded on the hollow carbon fiber. The FeS particles of the present invention are compounded on the surface of the hollow carbon fiber tube. In certain embodiments of the present invention, the morphology of the FeS is petal-shaped.

[0010] The biomass-based FeS particle composite fiber provided by the present invention adopts the carbide of tree cotton fiber as the hollow carbon fiber, utilizes the characteristics of high hollowness and light weight of tree cotton fiber, composites FeS on the hollow carbon fiber, improves the economic value of tree cotton biomass fiber and gives it functional application, realizes the specificity of the composite fiber in chemical and physical (thermal, optical, electromagnetic, etc.) properties.

[0011] The present invention also provides a method for preparing biomass-based FeS particle composite fibers, comprising the following steps: subjecting hollow carbon fibers to a hydrothermal reaction in a solution of iron salt and a complexing agent to obtain biomass-based FeS particle composite fibers; the hollow carbon fibers are carbides of tree cotton fibers.

[0012] The hollow carbon fiber of the present invention is a carbide of tree cotton fiber, which is prepared by selecting tree cotton fiber as a raw material and carbonizing it. Specifically, the present invention carbonizes the tree cotton fiber under the protection of an inert gas to obtain the carbide of the tree cotton fiber, that is, the above-mentioned hollow carbon fiber. In certain embodiments of the present invention, the hollowness of the tree cotton fiber is 85% to 90%; the fiber length of the tree cotton fiber is 31mm to 35mm; the fiber diameter of the tree cotton fiber is 16μm to 28μm. In certain embodiments of the present invention, the inert gas is nitrogen, and the purity of the nitrogen is more than 99.99%. In certain embodiments of the present invention, the temperature of the carbonization treatment is 600℃ to 800℃, and the time of the carbonization treatment is 1h to 6h. The present invention needs to maintain a slow temperature rise during the carbonization treatment of the tree cotton fiber; in one embodiment, the heating rate of the carbonization treatment is less than 2℃ / min, preferably 1℃ / min. In one embodiment, the temperature of the carbonization treatment is 800° C., the time of the carbonization treatment is 2 h, and the heating rate of the carbonization treatment is 2° C. / min.

[0013] After the present invention successfully prepares the tree cotton-based carbon tube, that is, after the hollow carbon fiber is prepared, a hydrothermal reaction is carried out based on it to grow FeS particles on its surface. In certain embodiments of the present invention, the hollowness of the hollow carbon fiber prepared above is 85% to 90%; the fiber diameter of the hollow carbon fiber is 10μm to 15μm; the carbon wall thickness of the hollow carbon fiber is 500nm to 1000nm.

[0014] The present invention conducts a hydrothermal reaction of the above-mentioned hollow carbon fiber in a solution of an iron salt and a complexing agent to obtain a biomass-based FeS particle composite fiber. In certain embodiments of the present invention, the iron salt and the complexing agent are dissolved in water respectively to obtain an iron salt solution and a complexing agent solution; the iron salt solution and the complexing agent solution are mixed and vigorously stirred to obtain a mixed solution; the above-mentioned hollow carbon fiber is immersed in the mixed solution for a hydrothermal reaction to obtain a biomass-based FeS particle composite fiber. In certain embodiments of the present invention, the hydrothermal reaction is carried out in a stainless steel autoclave lined with polytetrafluoroethylene, and the obtained product is washed and freeze-dried to obtain a biomass-based FeS particle composite fiber. In one embodiment, the temperature of the hydrothermal reaction is 150°C to 300°C; the time of the hydrothermal reaction is 10h to 40h. In one embodiment, the temperature of the hydrothermal reaction is 200°C; the time of the hydrothermal reaction is 24h.

[0015] In certain embodiments of the present invention, the iron salt is selected from one or more of FeSO4·7H2O, FeCl3·6H2O, and ferrocene; the complexing agent is selected from one or more of L-cysteine ​​and polyethyleneimine. In one embodiment, the complexing agent is selected from L-cysteine ​​with a content of 99wt%. In one embodiment, in the solution of the iron salt and the complexing agent, the mass concentration ratio of the iron salt to the complexing agent is 5 to 10:3. In one embodiment, in the solution of the iron salt and the complexing agent, the mass concentration ratio of the iron salt to the complexing agent is 7:3.

[0016] The present invention further includes pre-treating the above-mentioned hollow carbon fibers before subjecting the above-mentioned hollow carbon fibers to a hydrothermal reaction in a solution of an iron salt and a complexing agent. The present invention pre-treats the above-mentioned hollow carbon fibers to facilitate the subsequent growth of FeS particles on their surface. In certain embodiments of the present invention, the temperature of the pre-treatment is 30°C to 60°C; the time of the pre-treatment is 0.5h to 10h. In certain embodiments of the present invention, the pre-treatment is carried out in one or more solutions of sodium carbonate, sodium bicarbonate, and hydrogen peroxide. In one embodiment, the pre-treatment is specifically to successively immerse the above-mentioned hollow carbon fibers in one or more solutions of sodium carbonate, sodium bicarbonate, and hydrogen peroxide. In one embodiment, the pre-treatment is specifically to immerse the above-mentioned hollow carbon fibers in 30wt% hydrogen peroxide at a temperature of 40°C for 5h.

[0017] The present invention also provides an electromagnetic absorption material, comprising a fiber material and an insulating material; the fiber material is the composite fiber mentioned above or the composite fiber prepared by the method mentioned above.

[0018] The present invention provides a biomass-based FeS particle composite fiber, comprising a hollow carbon fiber and FeS composited on the carbon fiber; the hollow carbon fiber is a carbonide of tree cotton fiber. The biomass-based FeS particle composite fiber provided by the present invention is prepared by selecting biomass fibers with unique hollow morphology, performing carbonization treatment to obtain hollow carbon tube fibers, and then combining hydrothermal reaction to perform carbon tube-based magnetic particle composite materials. The hollow carbon / flower-shaped FeS particle composite fiber prepared by the present invention is prepared using tree cotton carbon-based materials with high hollowness and light weight. The preparation method is simple and the process is easy to control. The economic value of tree cotton biomass fibers is improved while giving them functional applications, and they show specificity in chemical and physical (thermal, optical, electromagnetic, etc.) properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the XRD pattern of the hollow carbon fiber material obtained in Example 1;

[0020] Figure 2 This is a SEM image of the hollow carbon fiber material obtained in Example 1;

[0021] Figure 3 This is a SEM image of the hollow carbon / flower-shaped FeS particle composite fiber obtained in Example 1;

[0022] Figure 4 The dielectric constant diagram of the hollow carbon fiber material obtained in Example 1;

[0023] Figure 5 Schematic diagram of the real and imaginary parts of the magnetic permeability of the hollow carbon fiber material obtained in Example 1;

[0024] Figure 6 This is a calculation diagram of the wave absorption performance of the hollow carbon fiber material obtained in Example 1;

[0025] Figure 7 The dielectric constant diagram of the hollow carbon / flower-shaped FeS particle composite fiber obtained in Example 1;

[0026] Figure 8 Schematic diagram of the real and imaginary parts of the magnetic permeability of the hollow carbon / flower-shaped FeS particle composite fiber obtained in Example 1;

[0027] Fig. 9 This is a calculation diagram of the microwave absorption performance of the hollow carbon / flower-shaped FeS particle composite fiber obtained in Example 1. DETAILED DESCRIPTION

[0028] The present invention discloses a biomass-based FeS particle composite fiber and a preparation method thereof and an electromagnetic absorption material. Those skilled in the art can refer to the content of this article and appropriately improve the process parameters to achieve it. It is particularly important to point out that all similar substitutions and modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention. The method and application of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the method and application of this article without departing from the content, spirit and scope of the present invention to realize and apply the technology of the present invention.

[0029] The present invention will be further described below in conjunction with embodiments:

[0030] Example 1

[0031] The biomass-based FeS particle composite fiber of the present invention is prepared according to the following steps:

[0032] Step 1: prepare hollow carbon tube fibers, select tree cotton fibers, a biomass fiber material, as raw materials, and obtain hollow carbon fiber materials after carbonization treatment; the carbonization treatment is to heat the temperature to 600°C for high-temperature treatment under the protection of inert gas nitrogen with a gas purity of ≥99.99%, maintain a slow heating rate of 1°C / min, and keep warm for 2 hours.

[0033] Step 2: Pretreatment of carbon fiber: pretreating the hollow carbon fiber material obtained in step 1 so that FeS particles can grow on its surface later; the pretreatment is performed by immersing in 30 wt % hydrogen peroxide for 5 hours.

[0034] Step 3: Riveting of flower-like FeS particles, the hollow carbon fiber material pretreated in step 2 is subjected to hydrothermal reaction to prepare hollow carbon / flower-like FeS particle composite fibers, specifically: 0.70g of FeSO4·7H2O and 0.30g of L-cysteine ​​are dissolved in 10mL of water respectively, and after obtaining two solutions, the two solutions are vigorously stirred and evenly mixed to obtain a mixed solution. Subsequently, the hollow carbon fiber material pretreated in step 2 is immersed in the mixed solution, and the obtained mixture is placed in a polytetrafluoroethylene-lined stainless steel autoclave at 200°C for a synthetic reaction for 24h. Finally, the obtained product is washed and freeze-dried to obtain the hollow carbon / flower-like FeS particle composite fiber of the present invention.

[0035] The hollow carbon fiber material obtained in step 1 of this embodiment was subjected to XRD and SEM detection, and the hollow carbon / flower-shaped FeS particle composite fiber obtained in step 3 was subjected to SEM detection. The detection results are as follows: Figures 1 to 3 shown. Figure 1 The XRD pattern of the hollow carbon fiber material obtained in Example 1 is shown in FIG. Figure 1 It can be seen that the tree cotton fibers after carbonization treatment are completely converted into amorphous elemental carbon. Figure 2 This is the SEM image of the hollow carbon fiber material obtained in Example 1. Figure 2 It can be seen that the morphology of the hollow carbon fiber material prepared after carbonization treatment replicates the hollow morphology of tree cotton, with a fiber diameter of 15 μm and a carbon wall thickness of about 600 nm. Figure 3 The SEM image of the hollow carbon / flower-shaped FeS particle composite fiber obtained in Example 1 is shown in FIG. Figure 3 It can be seen that FeS particles are successfully grown inside the hollow carbon tubes by the method of the present invention, and the morphology thereof is petal-shaped.

[0036] The hollow carbon fiber material obtained in step 1 was tested for electromagnetic parameters and wave absorption performance. The results are as follows: Figures 4 to 6 As shown, Figure 4 The dielectric constant diagram of the hollow carbon fiber material obtained in Example 1, Figure 5 Schematic diagram of the real and imaginary parts of the magnetic permeability of the hollow carbon fiber material obtained in Example 1, Figure 6The calculation diagram of the wave absorption performance of the hollow carbon fiber material obtained in Example 1. The real part and imaginary part of the magnetic permeability of the hollow carbon fiber material obtained in Example 1 are respectively concentrated near 1 and 0, which belongs to the magnetic permeability data characteristics of the composite dielectric loss type wave absorption material; due to the high dielectric constant, its wave absorption performance is poor, and the wave absorption performance is only the minimum reflection loss value of -18.2dB.

[0037] The electromagnetic parameters and microwave absorption performance of the hollow carbon / flower-shaped FeS particle composite fiber obtained in step 3 were tested. Figures 7 to 9 As shown, Figure 7 The dielectric constant diagram of the hollow carbon / flower-shaped FeS particle composite fiber obtained in Example 1 is shown in FIG. Figure 8 Schematic diagram of the real and imaginary parts of the magnetic permeability of the hollow carbon / flower-shaped FeS particle composite fiber obtained in Example 1, Fig. 9 The calculation diagram of the wave absorption performance of the hollow carbon / flower-like FeS particle composite fiber obtained in Example 1. It can be calculated that after the hollow carbon / flower-like FeS particle composite fiber is prepared at 600°C, its dielectric constant and magnetic permeability can be adjusted, and its wave absorption performance can be greatly improved. The minimum reflection loss can reach -60dB at 9.5GHz. It can be seen that the biomass-based hollow carbon / flower-like FeS particle composite fiber provided by the present invention can show specificity in electromagnetic absorption properties.

[0038] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A biomass-based FeS particle composite fiber, It is characterized in that The method comprises hollow carbon fibers and FeS composited on the hollow carbon fibers; the hollow carbon fibers are subjected to hydrothermal reaction in a solution of iron salt and a complexing agent to obtain biomass-based FeS particle composite fibers; The hollow carbon fiber is a carbonized product of tree cotton fiber; The hollowness of the hollow carbon fiber is 85% to 90%; The fiber diameter of the hollow carbon fiber is 10 μm to 15 μm; The carbon wall thickness of the hollow carbon fiber is 500 nm to 1000 nm.

2. A method for preparing biomass-based FeS particle composite fibers, It is characterized in that The following steps are involved: The hollow carbon fibers are subjected to a hydrothermal reaction in a solution of an iron salt and a complexing agent to obtain biomass-based FeS particle composite fibers; The hollow carbon fiber is a carbide of tree cotton fiber; the carbide of tree cotton fiber is prepared by carbonizing tree cotton fiber as a raw material; the temperature of the carbonization treatment is 600° C. to 800° C., and the time of the carbonization treatment is 1 h to 6 h; The hollowness of the tree cotton fiber is 85% to 90%; The fiber diameter of the tree cotton fiber is 16 μm to 28 μm; The iron salt is selected from FeSO 4 •7H 2 O, FeCl 3 •6H 2 O, one or more of ferrocene; The complexing agent is selected from one or more of L-cysteine ​​and polyethyleneimine; In the solution of the iron salt and the complexing agent, the mass concentration ratio of the iron salt to the complexing agent is 5-10:3; the temperature of the hydrothermal reaction is 150° C.-300° C.; The hydrothermal reaction time is 10 h~40 h.

3. The method according to claim 2, It is characterized in that Before the hydrothermal reaction, the hollow carbon fiber is pre-treated; The pretreatment temperature is 30°C to 60°C; the pretreatment time is 0.5 h to 10 h.

4. The method according to claim 3, It is characterized in that The pretreatment is carried out in one or more solutions of sodium carbonate, sodium bicarbonate and hydrogen peroxide.

5. An electromagnetic absorption material, It is characterized in that It comprises fiber material and insulating material; the fiber material is the composite fiber according to claim 1 or the composite fiber prepared by any one of the methods described in claims 2 to 4.

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