A kind of graphene/pyrolytic carbon/silicon carbide electromagnetic shielding composite material and preparation method thereof

A technology of electromagnetic shielding and composite materials, applied in the direction of magnetic/electric field shielding, electrical components, etc., can solve the problems of lack of structure and function, poor mechanical structure performance, etc., and achieve ultra-high mechanical structural performance, super electromagnetic shielding characteristics, Effect of excellent electromagnetic shielding performance

Active Publication Date: 2022-07-19
SHAANXI UNIV OF SCI & TECH
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  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] The purpose of the present invention is to provide a graphene / pyrolytic carbon / silicon carbide electromagnetic shielding composite material and its preparation method, which solves the problems that the existing electromagnetic shielding composite materials have poor mechanical structure performance and do not have the integration of structure and function

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  • A kind of graphene/pyrolytic carbon/silicon carbide electromagnetic shielding composite material and preparation method thereof
  • A kind of graphene/pyrolytic carbon/silicon carbide electromagnetic shielding composite material and preparation method thereof
  • A kind of graphene/pyrolytic carbon/silicon carbide electromagnetic shielding composite material and preparation method thereof

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preparation example Construction

[0036] The preparation method of a graphene / pyrolytic carbon / silicon carbide electromagnetic shielding composite material provided by the invention comprises the following steps:

[0037] Step 1, Preparation of Graphene Oxide (GO)

[0038] Slowly add 1-5 g of graphite powder and 0.5-2 g of sodium nitrate into 30-150 mL of concentrated sulfuric acid to obtain a mixture, which is placed in an ice-water bath at 0°C and mixed uniformly; then slowly add 3-20 g of potassium permanganate, Make it fully stirred in a 35°C water bath to obtain a strong oxidizing concentrated sulfuric acid / potassium permanganate / sodium nitrate-graphite mixture;

[0039] Then slowly add the concentrated sulfuric acid / potassium permanganate / sodium nitrate-graphite mixture into 30-150 mL of deionized water to obtain a dilution with a concentration ratio of the mixture to deionized water of 1;

[0040] The diluted product is then placed in a 90°C water bath to fully react for 30 to 60 minutes to obtain the ...

Embodiment 1

[0058] Step 1, preparation of graphene oxide (GO);

[0059] Weigh 1g of graphite powder and 0.5g of NaNO respectively 3 , which were successively added to 30 mL of concentrated H 2 SO 4 , the mixture was placed in an ice-water bath at 0°C and stirred well, and then 3g KMnO was slowly added. 4 , and then placed in a 35°C water bath to stir and react for 30min, then added to 30mL of deionized water, and reacted in a 90°C water bath for 15min. After the reaction was over, slowly add 5 mL of H with a mass concentration of 30%. 2 O 2 solution, let stand for a period of time, remove the lower layer of sediment, wash it by centrifugation with ethanol and water until the pH value is 5-7, and take the lower layer of sediment to be GO;

[0060] In step 2, the prepared GO was added with water to prepare a dispersion with a concentration of 3 mg / mL, ultrasonically treated for 3 hours, then frozen for 24 hours, and then freeze-dried for 48 hours to obtain a GO sponge three-dimensional ...

Embodiment 2

[0066] In step 1, graphene oxide is prepared in the same manner as in the first step of Example 1.

[0067] Step 2, adding water to the prepared graphene oxide to prepare a dispersion with a concentration of 3 mg / mL, ultrasonically treating it for 3 hours, freezing it for 24 hours, and then performing freeze-drying treatment for 48 hours to obtain a GO sponge three-dimensional framework.

[0068] In step 3, the prepared GO sponge three-dimensional skeleton is placed in a tube furnace, and the temperature is raised to 900° C. under nitrogen protection for 30 minutes of high temperature heat treatment to obtain a G sponge.

[0069] Step 4: Immerse the prepared G sponge in an ethanol solution with a mass fraction of 50% resin for 30 minutes, then place it in an oven for curing, and heat it up to 120° C. for 3 hours at 1° C. / min. Finally, it was put into a tube furnace for high temperature cracking with nitrogen gas, the cracking temperature was 900 °C, and the time was 2 hours; i...

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Abstract

A graphene / pyrolytic carbon / silicon carbide electromagnetic shielding composite material and a preparation method thereof provided by the present invention include the following steps: step 1, preparing a G sponge three-dimensional skeleton; The three-dimensional skeleton of the G sponge obtained in PyC and SiC was alternately impregnated and cracked in the order of PyC and SiC until it was completely densified to obtain G / (PyC‑SiC) n Electromagnetic shielding composite material; the multi-layered G / (PyC-SiC)n composite material prepared by the invention not only has the ultra-high specific strength of high-temperature structural materials, but also has both ultra-strong electromagnetic shielding properties and ultra-light density. The total electromagnetic shielding effectiveness (SET) is above 40dB, and it is expected to be used in the structural components of countermeasures.

Description

technical field [0001] The invention relates to the field of composite material preparation, in particular to a graphene / pyrolytic carbon / silicon carbide electromagnetic shielding composite material and a preparation method thereof. Background technique [0002] The rapid development of modern radar electromagnetic countermeasure technology makes future national defense and war face a huge threat. In order to counter electromagnetic interference and reconnaissance technology, the development of electromagnetic shielding and stealth absorbing materials has become an important direction of modern defense and military research. In recent years, with the rapid development of my country's aerospace and national defense technology, such as a new generation of stealth aircraft, radar electronic equipment, etc., traditional electromagnetic shielding and absorbing materials can no longer meet the needs of modern defense, structural electromagnetic shielding and absorbing materials hav...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C04B35/80C04B35/571C04B35/524H05K9/00
CPCC04B35/524C04B35/571H05K9/0081C04B2235/3826C04B2235/422C04B2235/52C04B2235/656C04B2235/6567C04B2235/658
Inventor 冯雷何鑫侯小江锁国权叶晓慧张荔杨艳玲张喆
Owner SHAANXI UNIV OF SCI & TECH
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