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Cobalt oxide/carbon composite nano wave-absorbing material and preparation method thereof

A nano-wave absorbing material, cobalt oxide technology, applied in cobalt oxide/cobalt hydroxide, inorganic material magnetism, hydrogen production and other directions, can solve the problems of principle and technical difficulties, complicated operation process, harsh reaction conditions, etc. The effect of cost, simple conditions, and easy control of conditions

Inactive Publication Date: 2010-06-09
XIAMEN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Ferromagnetic / dielectric nanocomposites such as α-Fe / Fe 3 B / Y 2 o 3 Composite particles, Fe / CNT, etc. have shown excellent wave-absorbing performance, but since the single-layer wave-absorbing material containing multi-phase wave-absorbing body is the most ideal wave-absorbing material, if it is to be obtained directly, it is difficult from the principle and technology. is very difficult
[0004] In the current research in this field, mainly by vapor deposition (Che, R.C.; Peng, L.M.; Duan, X.F. Microwave absorption enhancement and complex permittivity and permeability of Fe encapsulatedwithin carbon nanotubes [J]. Adv. Mater, 2004, 16 (5 ): 401.), arc discharge (Liu, X.G.; Geng, D.Y.; Zhang.Z.D.Microwave-absorption properties of ZnO-coated iron nanocapsules[J].Appl.Phys.Lett, 2008, 92:1731171.), heat treatment- Ball milling (Liu, J.R.; Itoh, M.; Machida.K.I.Electrtomagnetic waveabsorption properties of α-Fe / Fe 3 B / Y 2 o 3 nanocomposites in gigahertz range[J].Appl.Phys.Lett, 2000, 83(19): 4017.) and other methods to prepare ferromagnetic / dielectric nanocomposites, these methods have complex processes, relatively harsh reaction conditions, and relatively It is cumbersome and the yield is low, so it is limited to a certain extent in practical application

Method used

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  • Cobalt oxide/carbon composite nano wave-absorbing material and preparation method thereof
  • Cobalt oxide/carbon composite nano wave-absorbing material and preparation method thereof
  • Cobalt oxide/carbon composite nano wave-absorbing material and preparation method thereof

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Effect test

Embodiment 1

[0039] (1) Weigh 0.3g Co(NO 3 ) 2 ·6H 2 O, add 31mL of water, ethanol and diethanolamine mixed solvent (water:ethanol:diethanolamine=20:10:1) under magnetic stirring. After dissolving completely, put the solution into the polytetrafluoroethylene reactor .

[0040] (2) Put the reaction kettle into a stainless steel jacket and put it in an oven to heat to 180°C for 12 hours.

[0041] (3) After the reaction kettle is naturally cooled to room temperature, the supernatant liquid is taken out and the lower layer precipitate is separated by centrifugation, washed with absolute ethanol 3 times, and dried at 80°C to obtain the flake cobalt hydroxide precursor.

[0042] (4) Mix the precursor and oleylamine in a quartz tube at a volume ratio of 1:25, dissolve it ultrasonically, and then insert the quartz tube into a vertical tube furnace to quickly heat to 300°C, take out the quartz tube after 30 minutes, and add The absolute ethanol is allowed to stand, the precipitate is separated by centrif...

Embodiment 2

[0047] (1) Weigh 0.3g Co(NO 3 ) 2 ·6H 2 O, add 38mL of water, ethanol and diethanolamine mixed solvent (water:ethanol:diethanolamine=20:10:8) under magnetic stirring. After the solution is completely dissolved, put the solution into the polytetrafluoroethylene reactor .

[0048] (2) Put the reaction kettle into a stainless steel jacket and put it in an oven to heat to 180°C for 12 hours.

[0049] (3) After the reaction kettle is naturally cooled to room temperature, take out the supernatant liquid, centrifuge to separate the lower sediment, wash 3 times with absolute ethanol, and dry at 80°C to obtain the flower-like cobalt hydroxide precursor.

[0050] (4) Mix the precursor and oleylamine in a quartz tube at a volume ratio of 1:25, dissolve it ultrasonically, and then insert the quartz tube into a vertical tube furnace to quickly heat to 300°C, take out the quartz tube after 30 minutes, and add The absolute ethanol is allowed to stand, the precipitate is separated by centrifugation...

Embodiment 3

[0055] (1) Weigh 0.3g Co(NO 3 ) 2 ·6H 2 O, add 31mL of water, ethanol and diethanolamine mixed solvent (water:ethanol:diethanolamine=20:1:10) under magnetic stirring. After it is completely dissolved, put the solution into the polytetrafluoroethylene reactor .

[0056] (2) Put the reaction kettle into a stainless steel jacket and put it in an oven to heat to 180°C for 12 hours.

[0057] (3) After the reaction kettle is naturally cooled to room temperature, the supernatant liquid is taken out and the lower sediment is separated by centrifugation, washed with absolute ethanol 3 times, and dried at 80°C to obtain the cobalt hydroxide precursor.

[0058] (4) Mix the precursor and oleylamine in a quartz tube at a volume ratio of 1:25, dissolve it ultrasonically, and then insert the quartz tube into a vertical tube furnace to quickly heat it to 300°C, take out the quartz tube after 60 minutes, and add The absolute ethanol is allowed to stand, the precipitate is separated by centrifugation...

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Abstract

The invention discloses a cobalt oxide / carbon composite nano wave-absorbing material and a preparation method thereof and relates to a magnet / dielectric composite nano wave-absorbing material. The cobalt oxide / carbon composite nano wave-absorbing material has a core-shell structure, wherein the core is magnetic cobalt oxide; and the shell is a carbon layer. The preparation method comprises: adding a cobalt salt into a solvent, and after the cobalt salt is dissolved, filling the solution into a reaction kettle; placing the reaction kettle in an outer cover and heating the reaction kettle; after the reaction kettle cools naturally to room temperature, taking out supernatant liquor, carrying out centrifugal separation on lower precipitate, washing and drying the precipitate to obtain a flaky / flower-shaped cobalt hydroxide precursor; mixing the precursor and oleylamine in a quartz tube; after the precursor is dissolved, inserting the quartz tube in a tubular furnace to heat the quartz tube at a constant temperature for at least 20 minutes; and taking out the quartz tube, adding absolute ethanol, standing the mixture, carrying out centrifugal separation on the mixture, and washing and drying the precipitate to obtain the cobalt oxide / carbon magnet / dielectric composite nano wave-absorbing material.

Description

Technical field [0001] The invention relates to a ferromagnetic / dielectric composite nano-wave absorbing material, in particular to a core / shell type composite with ferromagnetic cobalt oxide as the core and dielectric amorphous carbon or graphite carbon as the outer shell Nano absorbing material and its preparation method. Background technique [0002] Radiation absorbing materials have a wide range of applications in the military field, and have become the key to the research on stealth technology of military equipment in various countries; and with the development of the electronics industry, the harm of electromagnetic radiation has become more and more serious. Electromagnetic radiation has become the next air pollution, water pollution and noise pollution. The fourth pollution source afterwards caused serious harm to the ecological environment and human health. The use of absorbing materials is an effective way to solve the harm of electromagnetic pollution. Therefore, the...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F1/12H01F1/36C01G51/04C01B3/02
Inventor 江智渊刘晶匡勤郑兰荪
Owner XIAMEN UNIV
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