scholarly journals Enhanced Electromagnetic Wave Absorption Properties of Ultrathin MnO2 Nanosheet-Decorated Spherical Flower-Shaped Carbonyl Iron Powder

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 135
Author(s):  
Zhengwei Qu ◽  
Yi Wang ◽  
Pingan Yang ◽  
Wei Zheng ◽  
Nan Li ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Iron Powder ◽  
Oxidation Resistance ◽  
Reflection Loss ◽  
Carbonyl Iron ◽  
Absorption Properties ◽  
Absorption Bandwidth ◽  
Electromagnetic Wave Absorption ◽  
Wave Absorption ◽  
Minimum Reflection Loss

In this work, spherical flower-shaped composite carbonyl iron powder@MnO2 (CIP@MnO2) with CIP as the core and ultrathin MnO2 nanosheets as the shell was successfully prepared by a simple redox reaction to improve oxidation resistance and electromagnetic wave absorption properties. The microwave-absorbing properties of CIP@MnO2 composites with different filling ratios (mass fractions of 20%, 40%, and 60% after mixing with paraffin) were tested and analyzed. The experimental results show that compared with pure CIP, the CIP@MnO2 composites have smaller minimum reflection loss and a wider effective absorption bandwidth than CIP (RL < −20 dB). The sample filled with 40 wt% has the best comprehensive performance, the minimum reflection loss is −63.87 dB at 6.32 GHz, and the effective absorption bandwidth (RL < −20 dB) reaches 7.28 GHz in the range of 5.92 GHz–9.28 GHz and 11.2 GHz–15.12 GHz, which covers most C and X bands. Such excellent microwave absorption performance of the spherical flower-like CIP@MnO2 composites is attributed to the combined effect of multiple beneficial components and the electromagnetic attenuation ability generated by the special spherical flower-like structure. Furthermore, this spherical flower-like core–shell shape aids in the creation of discontinuous networks, which improve microwave incidence dispersion, polarize more interfacial charges, and allow electromagnetic wave absorption. In theory, this research could lead to a simple and efficient process for producing spherical flower-shaped CIP@MnO2 composites with high absorption, a wide band, and oxidation resistance for a wide range of applications.

scholarly journals One-step hydrothermal synthesis of Ni–Fe–P/graphene nanosheet composites with excellent electromagnetic wave absorption properties

RSC Advances ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 5570-5581 ◽  
Author(s):  
Shuo Zhao ◽  
Chunyu Wang ◽  
Ting Su ◽  
Bo Zhong
Keyword(s):  
Electromagnetic Wave ◽  
Excellent Performance ◽  
Absorption Properties ◽  
Graphene Nanosheet ◽  
Absorption Bandwidth ◽  
Electromagnetic Wave Absorption ◽  
Wave Absorption ◽  
One Step ◽  
5 Ghz ◽  
Minimum Reflection Loss

Ni–Fe–P nanoparticle/graphene nanosheet composites synthesized by a one-step hydrothermal method have excellent performance in the field of electromagnetic wave absorption, with a minimum reflection loss of −50.5 dB and a maximum effective absorption bandwidth of 5 GHz.

scholarly journals Spawns Structure of Rod-Like ZnO Wrapped in Cellulose Nanofibers for Electromagnetic Wave Absorption

2017 ◽  
Vol 2017 ◽  
pp. 1-6
Author(s):  
Bitao Fan ◽  
Qiufang Yao ◽  
Chao Wang ◽  
Ye Xiong ◽  
Qingfeng Sun ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Reflection Loss ◽  
Cellulose Nanofibers ◽  
Absorption Properties ◽  
Composite Aerogel ◽  
Electromagnetic Wave Absorption ◽  
Wave Absorption ◽  
One Step ◽  
Absorption Performance ◽  
Minimum Reflection Loss

Spawns structure of rod-like ZnO wrapped in the cellulose nanofibers was successfully fabricated through a facile one-step hydrothermal method, and their electromagnetic wave absorption properties were investigated. The structure and properties of the composite aerogel were characterized. The enlarged morphology images showed that the as-prepared cellulose nanofiber/ZnO samples were spawns structure of rod-like ZnO wrapped in the cellulose nanofibers. The composite aerogel in a wax matrix exhibited excellent electromagnetic wave absorption performance over 2–18 GHz. The widest absorption bandwidth of 30 wt% contained with reflection loss values less than −10 dB was up to 12 GHz (6–18 GHz) at the thickness of 5.5 mm and the minimum reflection loss value reached −26.32 dB at 15.2 GHz when the thickness of the absorber was 3 mm.

scholarly journals Enhanced electromagnetic wave absorption property of binary ZnO/NiCo2O4 composites

2021 ◽  
Author(s):  
Bin Du ◽  
Mei Cai ◽  
Xuan Wang ◽  
Junjie Qian ◽  
Chao He ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Dielectric Properties ◽  
Hydrothermal Reaction ◽  
Absorption Property ◽  
Absorption Properties ◽  
Promising Candidate ◽  
Electromagnetic Wave Absorption ◽  
Wave Absorption ◽  
Absorbing Materials ◽  
Minimum Reflection Loss

AbstractNowadays, metal oxide-based electromagnetic wave absorbing materials have aroused widely attentions in the application of telecommunication and electronics due to their selectable mechanical and outstanding dielectric properties. Herein, the binary ZnO/NiCo2O4 nanoparticles were successfully synthesized via hydrothermal reaction and the electromagnetic wave absorption properties of the composites were investigated in detail. As a result, benefiting from the dielectric loss, the as-obtained ZnO/NiCo2O4-7 samples possessed a minimum reflection loss value of −33.49 dB at 18.0 GHz with the thickness of 4.99 mm. This work indicates that ZnO/NiCo2O4 composites have the promising candidate applications in electromagnetic wave absorption materials in the future.

Electromagnetic Wave Absorption Cement Based on Composited Absorbing Agent

2014 ◽  
Vol 1035 ◽  
pp. 520-523 ◽  
Author(s):  
Ye Sun ◽  
Yue Fang Zhang ◽  
Wan Jun Hao
Keyword(s):  
Electromagnetic Wave ◽  
Carbon Black ◽  
Electromagnetic Radiation ◽  
Glass Fiber ◽  
Radiation Protection ◽  
Reflection Loss ◽  
Absorption Properties ◽  
Electromagnetic Wave Absorption ◽  
Wave Absorption ◽  
Electromagnetic Radiations

To solve more and more serious electromagnetic radiations, electromagnetic wave absorption cement were prepared by introducing carbon black and glass fiber as composited absorbing reagent, wich can be useful in building anechoic chamber and other electromagnetic radiation protection to buildings. The results showed that the absorption properties were improved compared with single absorbing agent such as carbon or glass fiber. the lowest reflection loss of-11.3dB was obtained at 18 GHz of 5wt.% carbon black and 9wt.% glass fiber filled cement with thickness of 20mm. The increase of thickness separately can not improve the absorption properties.

Graphene–carbonyl iron cross-linked composites with excellent electromagnetic wave absorption properties

2014 ◽  
Vol 2 (32) ◽  
pp. 6582-6591 ◽  
Author(s):  
Zetao Zhu ◽  
Xin Sun ◽  
Hairong Xue ◽  
Hu Guo ◽  
Xiaoli Fan ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Carbonyl Iron ◽  
Framework Structure ◽  
Absorption Properties ◽  
Electromagnetic Wave Absorption ◽  
Wave Absorption ◽  
The Cross ◽  
Absorbing Property

A carbon-bridge effect was adopted to explain the electromagnetic wave absorbing property related to the cross-linked framework structure of RGO–SCI composites.

Investigation of the electromagnetic absorption properties of Ni@TiO2 and Ni@SiO2 composite microspheres with core–shell structure

2015 ◽  
Vol 17 (4) ◽  
pp. 2531-2539 ◽  
Author(s):  
Biao Zhao ◽  
Gang Shao ◽  
Bingbing Fan ◽  
Wanyu Zhao ◽  
Rui Zhang
Keyword(s):  
Electromagnetic Wave ◽  
Reflection Loss ◽  
Core Shell ◽  
Absorption Properties ◽  
Electromagnetic Wave Absorption ◽  
The Core ◽  
Composite Microspheres ◽  
Electromagnetic Absorption ◽  
Core Shell Structure ◽  
Minimum Reflection Loss

The core–shell Ni–SiO2 composite exhibits the best electromagnetic wave absorption in the GHz range with a minimum reflection loss of −40.0 dB, which is superior to those of Ni–TiO2 and Ni microspheres.

Broadband Micro-Wave Absorption Properties of Ni-P Coated Fe Nanoparticles by Electroless Plating Process

2012 ◽  
Vol 549 ◽  
pp. 665-669 ◽  
Author(s):  
Gui Mei Shi ◽  
Wei Min Sun ◽  
Da Wei Lu ◽  
Shu Lian
Keyword(s):  
Electromagnetic Wave ◽  
Layer Thickness ◽  
Reflection Loss ◽  
Electroless Plating ◽  
Coating Layer ◽  
Absorption Properties ◽  
Electromagnetic Wave Absorption ◽  
Wave Absorption ◽  
Absorption Layer ◽  
Fe Nanoparticles

Fe nanoparticles with shell of Ni-P coating layer were successfully synthesized using Ni electroless plating process. Electromagnetic-wave absorption of Ni-P coated Fe nanoparticles has been investigated. In contrast to earlier reported materials, the absorption amplitude of as-prepared samples is found not largely decrease with increasing absorption-layer thickness. A reflection loss (RL) exceeding -20 dB can be obtained for almost the whole frequencies within the 2-18GHz range by choosing an appropriate layer thickness between 0.9 and 6.0mm. The broadest bandwidth (RLu-bands(12-18GHz), is obtained for 1.1mm layer. At the same time, it is worth noticing that in a thin thickness range 0.91-2.0mm, the reflection loss (RL) exceeding -10 dB in the 6-18GHz range is obtained, which covers half of C-bands (4-8GHz), the whole X-bands (8-12GHz) and Ku–bands (12-18GHz).

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