Preparation method of polymer conversion ceramic-based wave-absorbing material loaded with nitrogen-doped graphene in situ

A nitrogen-doped graphene and wave-absorbing material technology, applied in the field of wave-absorbing materials, can solve the problems of easy-structure agglomeration wave-absorbing properties, cumbersome preparation methods, insufficiencies, etc. Effect

Active Publication Date: 2021-12-03
NORTHWESTERN POLYTECHNICAL UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In order to avoid the deficiencies of the prior art, the present invention proposes a method for preparing a polymer-converted ceramic-based wave-absorbing material that supports nitrogen-doped graphene in situ, which solves the tedious and easy preparation method of the existing graphene-doped PDCs material. Insufficient microwave absorption performance caused by structural agglomeration

Method used

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  • Preparation method of polymer conversion ceramic-based wave-absorbing material loaded with nitrogen-doped graphene in situ
  • Preparation method of polymer conversion ceramic-based wave-absorbing material loaded with nitrogen-doped graphene in situ
  • Preparation method of polymer conversion ceramic-based wave-absorbing material loaded with nitrogen-doped graphene in situ

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Experimental program
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Effect test

Embodiment 1

[0032] (1) First disperse 6g of urea into 15ml of xylene solution, then transfer it to a Schlenk device, add 6.6ml of liquid polysilazane, stir and react at 80°C for 2h, and then remove the organic solvent under vacuum. Solvent, you can get a single-source precursor;

[0033] (2) Put the obtained single-source precursor into a tube furnace, use nitrogen as a protective gas, and raise the temperature of the furnace to 300°C at a heating rate of 5°C / min, so that the precursor is fully cross-linked and solidified at this temperature 2h, after the heat preservation is completed, turn off the heating power supply and naturally cool down with the furnace. Fully grind and sieve the cured powder to obtain a 200-mesh precursor powder;

[0034] (3) Put the sieved precursor powder into a graphite crucible, then put the crucible into a high-temperature tube furnace, use nitrogen as a protective gas, and raise the furnace temperature to 900 °C at a heating rate of 5 °C / min. At this tempe...

Embodiment 2

[0036] (1) First disperse 3g of melamine into 15ml of xylene solution, then transfer it to a Schlenk device, add 6ml of liquid polysiloxane, stir and react at 80°C for 2h, and then remove the organic solvent under vacuum , the single-source precursor can be obtained;

[0037](2) Put the obtained single-source precursor into a tube furnace, use nitrogen as a protective gas, and raise the temperature of the furnace to 180°C at a heating rate of 5°C / min, so that the precursor is fully cross-linked and solidified at this temperature 5h, after the heat preservation is completed, turn off the heating power supply and naturally cool down with the furnace. Fully grind and sieve the cured powder to obtain a 300-mesh precursor powder;

[0038] (3) Put the sieved precursor powder into a graphite crucible, then put the crucible into a high-temperature tube furnace, use nitrogen as a protective gas, and raise the furnace temperature to 1000 °C at a heating rate of 5 °C / min. At this tempe...

Embodiment 3

[0040] (1) First disperse 10g of N,N'-methylenebisacrylamide into 30ml of xylene solution, then transfer it to a Schlenk device, add 5ml of liquid polysilazane, and stir at 100°C React for 3 hours, and then remove the organic solvent under vacuum to obtain a single-source precursor;

[0041] (2) Put the obtained single-source precursor into a tube furnace, use nitrogen as a protective gas, and raise the temperature of the furnace to 220°C at a heating rate of 5°C / min, so that the precursor is fully cross-linked and solidified at this temperature 2h, after the heat preservation is completed, turn off the heating power supply and naturally cool down with the furnace. Fully grind and sieve the cured powder to obtain a 300-mesh precursor powder;

[0042] (3) Put the sieved precursor powder into a graphite crucible, then put the crucible into a high-temperature tube furnace, use nitrogen as a protective gas, and raise the furnace temperature to 1100 °C at a heating rate of 8 °C / mi...

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Abstract

The invention relates to a preparation method of a polymer conversion ceramic-based wave-absorbing material loaded with nitrogen-doped graphene in situ. An organic nitrogen source reacts with a silicon-based polymer to generate a single-source precursor, and cracking and high-temperature heat treatment are carried out to enable the precursor to be self-assembled to generate the material. The single-source precursor is synthesized in one step through an organic chemical modification method, and the nitrogen-doped graphene-loaded polymer converted ceramic (NG-PDCs)-based composite material with excellent wave-absorbing performance is obtained through high-temperature cracking. The nitrogen-doped graphene loaded composite ceramic is converted from a synthesized single-source precursor, wherein nitrogen-doped graphene is uniformly distributed in polymer conversion ceramic. The NG with more excellent wave-absorbing performance is introduced in one step through chemical combination, so that the defects that preparation is tedious and the structure is prone to agglomeration due to the fact that graphene is added in a traditional method are overcome, and the wave-absorbing performance of the PDCs material is improved.

Description

technical field [0001] The invention belongs to the technical field of wave-absorbing materials, and relates to a method for preparing a polymer-converted ceramic-based wave-absorbing material in-situ loaded with nitrogen-doped graphene. Background technique [0002] Polymer derived ceramics (PDCs) technology has the characteristics of strong artificial design of ceramic precursor molecules, controllable phase domain size of pyrolytic ceramics, and the ability to obtain amorphous / nanocrystalline in-situ composite structures. It is widely used in the preparation of composite materials. Silicon-based PDCs (such as SiCN, SiOC, and SiBCN, etc.) exhibit excellent high-temperature stability, oxidation resistance, and creep resistance. On the basis of this, further high-temperature heat treatment can form SiC nanocrystals and free C in the ceramic The network structure increases the dielectric constant and electrical conductivity of the composite material, and has broad prospects ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/589C04B35/596C04B35/571C04B35/577C04B35/563C04B35/622
CPCC04B35/589C04B35/571C04B35/5603C04B35/563C04B35/622C04B2235/425C04B2235/6562C04B2235/6567C04B2235/96Y02E60/50
Inventor 付前刚张育育孙佳闫宁宁韩旭
Owner NORTHWESTERN POLYTECHNICAL UNIV
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