Preparation method of a silica-carbon fiber composite microwave absorbing material

Abstract

The present invention discloses a preparation method of a silica / carbon fiber composite microwave absorbing material, which relates to the technical field of electromagnetic wave absorbing materials. Deionized water is added to beaker A, and then carbon fibers are added to beaker A. The carbon fibers in the first solution in beaker A are uniformly dispersed through ultrasonic treatment and stirring. Cetyltrimethylammonium bromide and urea are added to beaker B and stirred until the second solution is clear. Sodium metasilicate nonahydrate and dilute hydrochloric acid are added to beaker C and stirred until a colloidal precipitate precipitates in the third solution. The first, second, and third solutions are mixed and stirred to obtain a first mixed solution. The first mixed solution is placed in a reaction kettle for hydrothermal reaction. The first mixed solution is stirred until a silica / carbon fiber composite material is obtained, and the water and the silica / carbon fiber composite material in the first mixed solution are separated by vacuum filtration. The obtained composite material is placed in a vacuum drying oven to obtain the final silica / carbon fiber composite microwave absorbing agent material.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic wave absorbing materials, and specifically to a preparation method of a silica / carbon fiber composite electromagnetic wave absorbing material. Background Art

[0002] In the field of electromagnetic wave absorbing materials, traditional carbon fiber materials have always been a popular material in this field due to their light weight, corrosion resistance, high and adaptable dielectric constant, etc. The present invention prepares a high-performance electromagnetic wave absorber that is corrosion-resistant and has the ability to absorb electromagnetic waves in a wide frequency band by compounding carbon fiber materials with silica materials; currently, there have been many studies on the compounding method of carbon fiber materials and silica materials. Han Wenbo et al. from Harbin Institute of Technology used the surface halogenation and azidation treatment of silica first, and then connected the carbon fiber after oxidation treatment to realize the compounding of silica materials on the surface of carbon fiber materials.

[0003] Existing methods have certain common problems. The preparation of composite materials requires multiple steps or the assistance of advanced equipment, with complex operations and is not conducive to large-scale production in factories. Therefore, a preparation method of a silica / carbon fiber composite electromagnetic wave absorbing material is now proposed, which is simple and has a simple preparation process. Summary of the Invention

[0004] To solve the deficiencies mentioned in the above background art, the purpose of the present invention is to provide a preparation method of a silica / carbon fiber composite electromagnetic wave absorbing material.

[0005] The purpose of the present invention can be achieved by the following technical solutions: A preparation method of a silica / carbon fiber composite electromagnetic wave absorbing material, characterized in that the method comprises the following steps:

[0006] Step 1: Add deionized water to beaker A, and then add carbon fiber to beaker A;

[0007] Step 2: Uniformly disperse the carbon fiber in the first solution in beaker A through ultrasonic treatment and stirring;

[0008] Step 3: Add cetyltrimethylammonium bromide and urea to beaker B, and stir until the second solution is clear;

[0009] Step 4: Add sodium metasilicate nonahydrate and dilute hydrochloric acid to beaker C, and stir until a colloidal precipitate precipitates in the third solution;

[0010] Step 5: Mix and stir the first solution, the second solution and the third solution to obtain a first mixed solution;

[0011] Step 6: Put the first mixed solution into a polytetrafluoroethylene reaction kettle for hydrothermal reaction;

[0012] Step 7: Stir the first mixed solution until the silica / carbon fiber composite material is evenly dispersed, and separate the water and the silica / carbon fiber composite material in the first mixed solution by vacuum filtration;

[0013] Step 8: Put the obtained silica / carbon fiber composite material into a vacuum drying oven to obtain the final silica / carbon fiber composite microwave absorbing agent material.

[0014] Further, the time of the ultrasonic treatment is 30 minutes.

[0015] Further, the stirring time for evenly dispersing the carbon fibers in the first solution in beaker A during the ultrasonic treatment and stirring is one hour.

[0016] Further, the molar ratio of cetyltrimethylammonium bromide to urea is 1:10, and the stirring time for stirring until the second solution becomes clear is 30 minutes.

[0017] Further, the concentration of the dilute hydrochloric acid is 1.2 mol / L.

[0018] Further, the stirring time for mixing and stirring the first solution, the second solution and the third solution is 30 minutes.

[0019] Further, the heat preservation temperature of the hydrothermal reaction is 150 °C, and the heat preservation time is 24 hours.

[0020] Further, the vacuum filtration time is 30 seconds.

[0021] Further, the temperature in the vacuum drying oven is 60 °C, and the vacuum drying time is 4 hours.

[0022] Advantages of the present invention:

[0023] In the process of using the present invention, deionized water is added to beaker A, and then carbon fiber is added to beaker A; the carbon fiber in the first solution in beaker A is uniformly dispersed by ultrasonic treatment and stirring; cetyltrimethylammonium bromide and urea are added to beaker B and stirred until the second solution becomes clear; sodium metasilicate nonahydrate and dilute hydrochloric acid are added to beaker C and stirred until a colloidal precipitate precipitates out in the third solution; the first solution, the second solution and the third solution are mixed and stirred to obtain a first mixed solution; the first mixed solution is placed in a polytetrafluoroethylene reaction kettle for hydrothermal reaction; the first mixed solution is stirred until the silica / carbon fiber composite material is uniformly dispersed, and the water and the silica / carbon fiber composite material in the first mixed solution are separated by vacuum filtration; the obtained silica / carbon fiber composite material is placed in a vacuum drying oven to obtain the final silica / carbon fiber composite wave-absorbing agent material. The preparation method of the present invention can effectively realize the composite of silica material and carbon fiber material without complex processes or advanced equipment; simply control the molar ratio of carbon fiber and silica material to control the conductivity of the final sample; the preparation method of the present invention can effectively improve the electromagnetic wave absorption performance of the silica carbon fiber material. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 is the flow chart of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0027] As Figure 1 shown, a preparation method of a silica / carbon fiber composite wave-absorbing material is characterized in that the method includes the following steps:

[0028] Step 1: Add deionized water to beaker A, and then add carbon fiber to beaker A;

[0029] Step 2: Uniformly disperse the carbon fiber in the first solution in beaker A by ultrasonic treatment and stirring;

[0030] Step 3: Add cetyltrimethylammonium bromide and urea into beaker B, and stir until the second solution becomes clear;

[0031] Step 4: Add sodium metasilicate nonahydrate and dilute hydrochloric acid into beaker C, and stir until a colloidal precipitate forms in the third solution;

[0032] Step 5: Mix and stir the first solution, the second solution and the third solution to obtain a first mixed solution;

[0033] Step 6: Place the first mixed solution into a polytetrafluoroethylene autoclave for hydrothermal reaction;

[0034] Step 7: Stir the first mixed solution until the silica / carbon fiber composite is evenly dispersed, and separate the water and the silica / carbon fiber composite in the first mixed solution by vacuum filtration;

[0035] Step 8: Place the obtained silica / carbon fiber composite into a vacuum drying oven to obtain the final silica / carbon fiber composite absorbing agent material.

[0036] It should be further noted that, in the specific implementation process, the time of the ultrasonic treatment is 30 minutes.

[0037] It should be further noted that, in the specific implementation process, the stirring time for the ultrasonic treatment and the stirring to evenly disperse the carbon fibers in the first solution in beaker A is one hour.

[0038] It should be further noted that, in the specific implementation process, the molar ratio of cetyltrimethylammonium bromide to urea is 1:10, and the stirring time until the second solution becomes clear is 30 minutes.

[0039] It should be further noted that, in the specific implementation process, the concentration of the dilute hydrochloric acid is 1.2 mol / L.

[0040] It should be further noted that, in the specific implementation process, the stirring time for mixing and stirring the first solution, the second solution and the third solution is 30 minutes.

[0041] It should be further noted that, in the specific implementation process, the heat preservation temperature of the hydrothermal reaction is 150 °C, and the heat preservation time is 24 hours.

[0042] It should be further noted that, in the specific implementation process, the vacuum filtration time is 30 seconds.

[0043] It should be further noted that, in the specific implementation process, the temperature in the vacuum drying oven is 60 °C, and the vacuum drying time is 4 hours.

[0044] Example 1:

[0045] Step S1: Preparation of carbon fiber dispersion liquid

[0046] Add 0.06 g of carbon fiber into beaker A, and then add 60 mL of deionized water.

[0047] Put it into an ultrasonic disperser and perform ultrasonic treatment for 30 min.

[0048] Stir the solution until the carbon fiber is completely dispersed and evenly distributed in the deionized water, thus completing the preparation of the carbon fiber dispersion liquid.

[0049] Step S2: Preparation of silica precursor

[0050] Add 0.0364 g of cetyltrimethylammonium bromide into beaker B, and then add 15 mL of deionized water. Stir the solution in beaker B until it becomes clear, then add 0.0607 g of urea and stir until the solution becomes clear.

[0051] Add 1.47 g of sodium metasilicate nonahydrate into beaker C, and then add 8.61 mL of dilute hydrochloric acid with a solution concentration of 1.2 mol / L. Stir until a colloidal precipitate appears in the solution.

[0052] Add the solution in beaker B into beaker C to complete the preparation of the silica precursor.

[0053] Step S3: Preparation of silica-carbon fiber composite material

[0054] Add the solution in beaker C into beaker A and stir for about half an hour.

[0055] Add the solution in beaker A into a polytetrafluoroethylene hydrothermal reaction kettle and react at 150 °C for about 24 h.

[0056] Pour the solution after hydrothermal reaction into beaker D and stir until the silica / carbon fiber composite powder is evenly dispersed.

[0057] Place a polyvinylidene fluoride filtration membrane with a pore size of 220 nm on the sand core of a suction filter flask, set up the suction filtration device, pour the evenly dispersed solution in solution D into the suction filtration device, and start suction filtration. After about 30 s, remove the suction filtration membrane attached with the silica / carbon fiber composite material.

[0058] Put the suction-filtered silica-carbon fiber composite material into a vacuum drying oven and dry it at 60 °C for about 4 h to complete the preparation of the silica / carbon fiber composite wave-absorbing material.

[0059] Example 2:

[0060] Step W1: Preparation of carbon fiber dispersion liquid

[0061] Add 0.06 g of carbon fiber to beaker A and add 60 mL of deionized water.

[0062] Place it in an ultrasonic disperser and ultrasonically treat for 30 min.

[0063] Stir the solution until the carbon fiber is completely and evenly dispersed in the deionized water to complete the preparation of the carbon fiber dispersion.

[0064] Step W2: Preparation of silica precursor

[0065] Add 0.0364 g of cetyltrimethylammonium bromide to beaker B, add 15 mL of deionized water, stir the solution in beaker B until the solution is clear, add 0.0607 g of urea to beaker B, and stir until the solution is clear.

[0066] Add 1.421 g of sodium metasilicate nonahydrate to beaker C, add 8.33 mL of dilute hydrochloric acid with a solution concentration of 1.2 mol / L, and stir until a colloidal precipitate precipitates from the solution.

[0067] Add the solution in beaker B to beaker C to complete the preparation of the silica precursor.

[0068] Step W3: Preparation of silica-carbon fiber composite

[0069] Add the solution in beaker C to beaker A and stir for about half an hour.

[0070] Add the solution in beaker A to a polytetrafluoroethylene hydrothermal reaction kettle and react at 150 °C for about 24 h.

[0071] Pour the solution after hydrothermal reaction into beaker D and stir until the silica / carbon fiber composite powder is evenly dispersed.

[0072] Place a polyvinylidene fluoride filtration membrane with a pore size of 220 nm on the sand core of the suction filter flask, set up the suction filtration device, pour the evenly dispersed solution in solution D into the suction filtration device, and start suction filtration. After about 30 s, remove the filtration membrane attached with the silica / carbon fiber composite.

[0073] Put the suction-filtered silica-carbon fiber composite into a vacuum drying oven and dry at 60 °C for about 4 h to complete the preparation of the silica / carbon fiber composite wave-absorbing material.

[0074] Example 3:

[0075] Step T1: Preparation of carbon fiber dispersion

[0076] Add 0.06 g of carbon fiber to beaker A and add 60 mL of deionized water.

[0077] Place it in an ultrasonic disperser and ultrasonically treat for 30 min.

[0078] Stir the solution until the carbon fibers are completely and evenly dispersed in deionized water, thus completing the preparation of the carbon fiber dispersion.

[0079] Step T2: Preparation of the silica precursor

[0080] Add 0.0364 g of cetyltrimethylammonium bromide to beaker B, and then add 15 mL of deionized water. Stir the solution in beaker B until it becomes clear. Add 0.0607 g of urea to beaker B and stir until the solution is clear.

[0081] Add 0.947 g of sodium metasilicate nonahydrate to beaker C, and then add 5.56 mL of dilute hydrochloric acid with a solution concentration of 1.2 mol / L. Stir until a colloidal precipitate forms in the solution.

[0082] Add the solution in beaker B to beaker C to complete the preparation of the silica precursor.

[0083] Step T3: Preparation of the silica-carbon fiber composite

[0084] Add the solution in beaker C to beaker A and stir for about half an hour.

[0085] Add the solution in beaker A to a polytetrafluoroethylene hydrothermal reaction kettle and react at 150 °C for about 24 h.

[0086] Pour the solution after the hydrothermal reaction into beaker D and stir until the silica / carbon fiber composite powder is evenly dispersed.

[0087] Place a polyvinylidene fluoride filtration membrane with a pore size of 220 nm on the sand core of a suction flask, set up the suction filtration device, pour the evenly dispersed solution in solution D into the suction filtration device, and start suction filtration. After about 30 s, remove the filtration membrane attached with the silica / carbon fiber composite.

[0088] Put the suction-filtered silica-carbon fiber composite into a vacuum drying oven and dry it at 60 °C for about 4 h to complete the preparation of the silica / carbon fiber composite microwave absorption material.

[0089] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A preparation method of a silica carbon fiber composite microwave absorbing material, characterized in that, The method comprises the following steps: Step 1: Add deionized water into beaker A, and then add carbon fiber into beaker A; Step 2: Make the carbon fiber in the first solution in beaker A be uniformly dispersed through ultrasonic treatment and stirring; Step 3: Add cetyltrimethylammonium bromide and urea into beaker B, and stir until the second solution is clear; Step 4: Add sodium metasilicate nonahydrate and dilute hydrochloric acid into beaker C, and stir until a colloidal precipitate precipitates out in the third solution; Step 5: Mix and stir the first solution, the second solution and the third solution to obtain a first mixed solution; Step 6: Put the first mixed solution into a polytetrafluoroethylene reaction kettle for hydrothermal reaction; The heat preservation temperature of the hydrothermal reaction is 150 °C, and the heat preservation time is 24 hours; Step 7: Stir the first mixed solution until the silicon dioxide / carbon fiber composite material is uniformly dispersed, and separate the water in the first mixed solution and the silicon dioxide / carbon fiber composite material by vacuum filtration; Step 8: Put the obtained silicon dioxide / carbon fiber composite material into a vacuum drying oven to obtain the final silicon dioxide / carbon fiber composite absorbent material; The temperature in the vacuum drying oven is 60 °C, and the vacuum drying time is 4 hours.

2. The preparation method of a silica carbon fiber composite wave-absorbing material according to claim 1, characterized in that, The time of the ultrasonic treatment is 30 minutes.

3. The preparation method of a silica-carbon fiber composite microwave absorbing material according to claim 1, characterized in that, The stirring time for making the carbon fiber in the first solution in beaker A be uniformly dispersed through ultrasonic treatment and stirring is one hour.

4. The preparation method of a silica-carbon fiber composite microwave absorbing material according to claim 1, characterized in that The molar ratio of the cetyltrimethylammonium bromide to the urea is 1:10, and the stirring time for stirring until the second solution is clear is 30 minutes.

5. The preparation method of a silica carbon fiber composite wave-absorbing material according to claim 1, characterized in that, The concentration of the dilute hydrochloric acid is 1.2 mol / L.

6. The preparation method of a silica carbon fiber composite wave-absorbing material according to claim 1, characterized in that, The stirring time for mixing and stirring the first solution, the second solution and the third solution is 30 minutes.

7. The preparation method of a silica carbon fiber composite microwave absorbing material according to claim 1, characterized in that, The vacuum filtration time is 30 seconds.

Images