Double-shell-structure carbonyl iron powder composite wave-absorbing material and preparation method thereof

Abstract

The invention discloses a double-shell-structure carbonyl iron powder composite wave-absorbing material and a preparation method thereof, wherein the composite wave-absorbing material is of a double shell layer core-shell structure, the core is carbonyl iron powder, the inner layer of the double-shell layer is an insulating layer, and the outer layer of the double-shell layer is a magnetic layer;the thickness of the insulating layer is 1 nm-1 [mu] m; and the thickness of the magnetic layer is 1nm-5 [mu] m; the preparation method comprises the following steps: coating the surface of the carbonyl iron powder with the insulating layer and coating the surface of a core-shell structure precursor by a chemical coprecipitation method. The surface of the carbonyl iron powder is coated with the double-shell layer by the chemical coprecipitation method. The impedance matching characteristic of the material is greatly improved, meanwhile, a large amount of nano-interface heterojunction is formedat the interfaces of the inner core and the double-shell layer, so that interface polarization is effectively induced, the scattering effect is formed for electron migration, and electromagnetic waveloss mechanisms such as multi-reflection absorption, strong ] ferromagnetic resonance and eddy current loss and the like of the material are greatly improved, so that the wave absorbing performance of the material is remarkably improved; the composite wave-absorbing material is simple in preparation method, is uniform and compact in coating and controllable in coating layer thickness and particlesize.

Description

technical field

[0001] The invention relates to an electromagnetic wave absorbing material, in particular to a double-shell structure carbonyl iron powder composite wave-absorbing material and its preparation method, specifically to a double-shell structure MFe 2 o 4 / SiO 2 The invention relates to a carbonyl iron powder composite wave absorbing material and a preparation method thereof, belonging to the technical field of electromagnetic wave absorbing materials. Background technique

[0002] Electromagnetic interference between internal components of equipment, electromagnetic stealth technology in the military field, microwave guidance of missiles, information leakage in the field of wireless communication, etc. have drawn wide attention to electromagnetic wave absorbing materials. Broadband, strong absorption of electromagnetic wave absorbing material. When the electromagnetic wave is incident on the surface of the wave-absorbing material, the incident electromagnetic...

Examples

Embodiment 1

[0049] mn 0.6 Zn 0.4 Fe 2 o 4 / SiO 2 / Preparation of carbonyl iron powder composite absorbing material:

[0050] Take 100g of carbonyl iron powder and wash it twice with alcohol to remove impurities and oil stains on the surface. Mix the cleaned carbonyl iron powder with deionized water, stir, add KH550 surface modifier dropwise, and stir for 1 hour. Then add tetraethyl orthosilicate TEOS to the mixture, and drop an appropriate amount of ammonia water NH 4 OH, adjust the pH of the solution to about 10, and stir vigorously for 4 hours until the reaction is complete. The mass percentages of carbonyl iron powder, deionized water, surface modifier and TEOS in the reaction system are: 1:10:0.02:0.1. After the reaction, carbonyl iron powder / SiO with core-shell structure was magnetically separated 2 powder, washed with absolute ethanol or deionized water until the filtrate was clear, and dried at 50°C for 1 h for later use.

[0051] Prepared Mn 0.6 Zn 0.4 Fe 2 o 4 Ferri...

Embodiment 2

[0054] NiFe 2 o 4 / SiO 2 / Preparation of carbonyl iron powder composite absorbing material:

[0055] Take 100g of carbonyl iron powder and wash it with alcohol for 3 times to remove impurities and oil stains on the surface. Mix the cleaned carbonyl iron powder with alcohol, stir, add KH560 surface modifier dropwise, and stir for 0.5h. Then, tetraethyl orthosilicate TEOS was added to the mixture, and an appropriate amount of NaOH solution was added dropwise to adjust the pH value of the solution to about 9, and the mixture was vigorously stirred for 2 hours until the reaction was complete. The mass percentages of carbonyl iron powder, alcohol, KH560 and TEOS in the reaction system are: 1:3:0.01:0.02. After the reaction, carbonyl iron powder / SiO with core-shell structure was magnetically separated 2 powder, washed with absolute ethanol or deionized water until the filtrate was clear, and dried at 100°C for 1 h for later use. Weigh an appropriate amount of Ni(NO 3 ) 2 ·6...

Embodiment 3

[0058] CoFe 2 o 4 / SiO 2 / Preparation of carbonyl iron powder composite absorbing material:

[0059] Take 100g of carbonyl iron powder and wash it twice with alcohol to remove impurities and oil stains on the surface. Mix the cleaned carbonyl iron powder with alcohol, stir, add KH550 surface modifier dropwise, and stir for 1h. Then add tetraethyl orthosilicate TEOS to the mixture, and add an appropriate amount of ammonia water dropwise to adjust the pH value of the solution to about 7, and stir vigorously for 2 hours until the reaction is complete. The mass percentages of carbonyl iron powder, alcohol, KH550 and TEOS in the reaction system are: 1:8:0.05:0.3. After the reaction, carbonyl iron powder / SiO with core-shell structure was magnetically separated 2 powder, washed with absolute ethanol or deionized water until the filtrate was clear, and dried at 50°C for 1 h for later use. Weigh an appropriate amount of CoCl 2 and FeCl 3 ·6H 2 O, dissolved in deionized water ...

technical field

[0001] The invention relates to an electromagnetic wave absorbing material, in particular to a double-shell structure carbonyl iron powder composite wave-absorbing material and its preparation method, specifically to a double-shell structure MFe 2 o 4 / SiO 2 The invention relates to a carbonyl iron powder composite wave absorbing material and a preparation method thereof, belonging to the technical field of electromagnetic wave absorbing materials. Background technique

[0002] Electromagnetic interference between internal components of equipment, electromagnetic stealth technology in the military field, microwave guidance of missiles, information leakage in the field of wireless communication, etc. have drawn wide attention to electromagnetic wave absorbing materials. Broadband, strong absorption of electromagnetic wave absorbing material. When the electromagnetic wave is incident on the surface of the wave-absorbing material, the incident electromagnetic...

Examples

Embodiment 1

[0049] mn 0.6 Zn 0.4 Fe 2 o 4 / SiO 2 / Preparation of carbonyl iron powder composite absorbing material:

[0050] Take 100g of carbonyl iron powder and wash it twice with alcohol to remove impurities and oil stains on the surface. Mix the cleaned carbonyl iron powder with deionized water, stir, add KH550 surface modifier dropwise, and stir for 1 hour. Then add tetraethyl orthosilicate TEOS to the mixture, and drop an appropriate amount of ammonia water NH 4 OH, adjust the pH of the solution to about 10, and stir vigorously for 4 hours until the reaction is complete. The mass percentages of carbonyl iron powder, deionized water, surface modifier and TEOS in the reaction system are: 1:10:0.02:0.1. After the reaction, carbonyl iron powder / SiO with core-shell structure was magnetically separated 2 powder, washed with absolute ethanol or deionized water until the filtrate was clear, and dried at 50°C for 1 h for later use.

[0051] Prepared Mn 0.6 Zn 0.4 Fe 2 o 4 Ferri...

Embodiment 2

[0054] NiFe 2 o 4 / SiO 2 / Preparation of carbonyl iron powder composite absorbing material:

[0055] Take 100g of carbonyl iron powder and wash it with alcohol for 3 times to remove impurities and oil stains on the surface. Mix the cleaned carbonyl iron powder with alcohol, stir, add KH560 surface modifier dropwise, and stir for 0.5h. Then, tetraethyl orthosilicate TEOS was added to the mixture, and an appropriate amount of NaOH solution was added dropwise to adjust the pH value of the solution to about 9, and the mixture was vigorously stirred for 2 hours until the reaction was complete. The mass percentages of carbonyl iron powder, alcohol, KH560 and TEOS in the reaction system are: 1:3:0.01:0.02. After the reaction, carbonyl iron powder / SiO with core-shell structure was magnetically separated 2 powder, washed with absolute ethanol or deionized water until the filtrate was clear, and dried at 100°C for 1 h for later use. Weigh an appropriate amount of Ni(NO 3 ) 2 ·6...

Embodiment 3

[0058] CoFe 2 o 4 / SiO 2 / Preparation of carbonyl iron powder composite absorbing material:

[0059] Take 100g of carbonyl iron powder and wash it twice with alcohol to remove impurities and oil stains on the surface. Mix the cleaned carbonyl iron powder with alcohol, stir, add KH550 surface modifier dropwise, and stir for 1h. Then add tetraethyl orthosilicate TEOS to the mixture, and add an appropriate amount of ammonia water dropwise to adjust the pH value of the solution to about 7, and stir vigorously for 2 hours until the reaction is complete. The mass percentages of carbonyl iron powder, alcohol, KH550 and TEOS in the reaction system are: 1:8:0.05:0.3. After the reaction, carbonyl iron powder / SiO with core-shell structure was magnetically separated 2 powder, washed with absolute ethanol or deionized water until the filtrate was clear, and dried at 50°C for 1 h for later use. Weigh an appropriate amount of CoCl 2 and FeCl 3 ·6H 2 O, dissolved in deionized water ...

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