Egg yolk shell hollow ferroferric oxide@air@carbon nano composite wave-absorbing material and preparation method thereof

A technology of ferroferric oxide and carbon nanocomposite, applied in shielding materials, electrical components, magnetic field/electric field shielding, etc., can solve problems affecting the normal operation of the immune system, secret electromagnetic signal leakage, human health hazards, etc., and achieve easy regulation The effect of microwave absorption performance, low filling ratio, and no secondary pollution

Active Publication Date: 2021-05-25
ZHEJIANG UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] In recent years, with the extensive development and application of communication equipment and electronic equipment, it has provided great convenience for human beings, but it has also caused considerable electromagnetic pollution. It will not only cause secret electromagnetic signal leakage and electromagnetic wave interference, but also make the human body Health is endangered, long-term exposure to high electromagnetic radiation pollution will affect the normal work of the immune system and increase the risk of disease

Method used

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  • Egg yolk shell hollow ferroferric oxide@air@carbon nano composite wave-absorbing material and preparation method thereof
  • Egg yolk shell hollow ferroferric oxide@air@carbon nano composite wave-absorbing material and preparation method thereof
  • Egg yolk shell hollow ferroferric oxide@air@carbon nano composite wave-absorbing material and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036](1) Weigh 3.2436 g of sodium citrate, 7.0584 g of sodium citrate and 2.1624 g of urea, sequentially dissolved in 210 mL deionized water, then add 1.8 g of polyacrylamide, stir the solution at room temperature 5 h to uniform Clarified, the rear polytetrafluoroethylene liner washed 10 h at 200 ° C at 200 ° C, and the resulting black mud product was washed 5 times with deionized water, and no water ethanol washing 3 times, drying at 60 ° C, that is, the hollow tetoxide Iron nanoparticles;

[0037](2) Weighing 300 mg of hollow tetrashydriobiobiometers dispersed in 150 ml of ethanol, 50 ml deionized water mixed solution, ultrasonic dispersion of 30 min, adding 4 mL of concentrated ammonia water (concentration of 25 wt / %), mechanical stirring 5 MIN, 1 mL of TEOS (tetraeth ester) was added, and once again, it was added once, a total of 3 times, mechanically stirred 6 h, the resulting product was washed 5 times with ethanol, 60 ° C drying, FE3O4@Sio2Nanoparticles;

[0038](3) Weigh 100 mg ...

Embodiment 2

[0046]Example 2 The difference from Embodiment 1 is that in step (5), the calcination temperature is 700 ° C, and the remaining process conditions are identical, and the black product made by the example is Named P-700.

[0047]The egg yolk hydroforming three iron @ air @ carbon nano-composite absorbing material (P-700) is mixed with paraffin, and the ratio of paraffin is 7.00 mm in the special mold. The inner diameter is 3.04 mm, the thickness of about 2 mm is 30%, and the product mass fraction is 30%, and the electromagnetic parameters are tested using the N5224A vector network analyzer, calculated to obtain the absorbing performance, and the test frequency range is 2-18 GHz.

[0048]The reflection loss of the sample P-700 follows the frequency change curve such asFigure 4As shown, when the thickness of the coating is 3 mm, the maximum absorption intensity of the composite can reach -27.7 dB; when the thickness of the coating is 2 mm, the effective absorption band is as high as 8 GHz, w...

Embodiment 3

[0050]Example 3 The difference from Embodiment 1 is that in step (5), the calcination temperature is 800 ° C, and the remaining process conditions are identical, and the black product made by this embodiment is named P-800.

[0051]The egg yolk housing hollow tetraned iron @ air @ carbon nanocomposite absorbing material (P-800) is mixed with paraffin, and the ratio of paraffin is 70% by 70% by weight, and it is pressed into an outer diameter of 7.00 mm in a special mold. The inner diameter is 3.04 mm, the thickness of about 2 mm is 30%, and the product mass fraction is 30%, and the electromagnetic parameters are tested using the N5224A vector network analyzer, calculated to obtain the absorbing performance, and the test frequency range is 2-18 GHz.

[0052]When the coating has a thickness of 5.5 mm, the egg yolk housing hollow tetraned iron @ air @ carbon nanocomposite absorbing material can be up to -25 dB, and the effective absorption bandwidth is 2 GHz.

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Abstract

The invention relates to the technical field of electromagnetic wave absorption, in particular to a yolk shell hollow ferroferric oxide@air@carbon nano composite wave-absorbing material and a preparation method thereof, and the preparation method comprises the following steps: (1) coating SiO2 on the surfaces of hollow ferroferric oxide nano particles; (2) carrying out carboxylation modification on the surface; (3) growing MIL-100 (Fe) on the surface in situ; (4) carrying out high-temperature calcination in a nitrogen atmosphere; and (5) heating and stirring in alkali liquor to remove the SiO2 layer, washing and drying to obtain the yolk shell hollow ferroferric oxide@air@ nano composite wave-absorbing material. The preparation method disclosed by the invention is low in cost, green and safe, free from any toxic and harmful substances, free from secondary pollution and easy for large-scale synthesis, and has an industrialization prospect. The yolk shell hollow ferroferric oxide@air@carbon nano composite wave-absorbing material prepared by the preparation method has the characteristics of small thickness, light weight, low filling ratio, strong absorption, wide frequency band and easiness in regulation and control of wave-absorbing performance, and has a wide application prospect.

Description

Technical field[0001]The present invention relates to the field of electromagnetic wave absorption, and more particularly to a metal organic frame-derived egg yolk shell hollow tetraned iron @ air @ carbon nanocomposite absorbing material and a preparation method thereof.Background technique[0002]In recent years, with the extensive development and application of communication equipment and electronic equipment, it provides a great convenience of mankind and also causes considerable electromagnetic pollution. It will not only cause the secret electromagnetic signal leakage and electromagnetic interference, but also make the human body. Health is harmful, and the environment in high electromagnetic radiation pollution will affect the normal operation of the immune system to increase the risk of illness. In addition, radar is an important role in the military sector, which uses electromagnetic wave detection target positioning, and its principle is to rely on emitted electromagnetic wa...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H05K9/00
CPCH05K9/0073
Inventor 胡军杨华栋潘剑南
Owner ZHEJIANG UNIV OF TECH
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