Double-Layered Cement Composites with Superior Electromagnetic Wave Absorbing Properties Containing Carbon Black and Expanded Polystyrene

2013 ◽  
Vol 774-776 ◽  
pp. 747-752 ◽  
Author(s):  
Yue Fang Zhang ◽  
Wan Jun Hao ◽  
Bao Yi Li ◽  
Yu Ping Duan ◽  
Shun Hua Liu
Keyword(s):  
Electromagnetic Wave ◽  
Carbon Black ◽  
High Performance ◽  
Expanded Polystyrene ◽  
Cement Composites ◽  
Frequency Range ◽  
Electromagnetic Wave Absorption ◽  
Matching Layer ◽  
Layer Composite ◽  
New Material

This paper reported that, using the method of double layer composite successfully prepared high performance of electromagnetic wave absorption materials. Such a composite is composed of a cement matching layer filled with expanded polystyrene (EPS) beads and an absorbing cement layer made of EPS beads and carbon black. The samples were tested by arching method in the frequency range of 8~18GHz. The reflectivities were revealed to be excellent, the lowest being-17dB. The new material can be used for building indoor electromagnetic radiation protection.

Electromagnetic Wave Absorption Properties of Cement Filled with Carbon Black

2014 ◽  
Vol 496-500 ◽  
pp. 2431-2434 ◽  
Author(s):  
Yue Fang Zhang ◽  
Wan Jun Hao ◽  
Yu Ping Duan ◽  
Shun Hua Liu
Keyword(s):  
Electromagnetic Wave ◽  
Dielectric Loss ◽  
Carbon Black ◽  
High Frequency ◽  
Filling Ratio ◽  
Frequency Range ◽  
Absorption Properties ◽  
Electromagnetic Wave Absorption ◽  
Testing Method ◽  
New Material

Using the dielectric loss property of carbon black , cement-based composites were prepared by introducing carbon black into cement. The reflection losses were studied using arched testing method in the frequency range of 2~18 GHz. The results showed that the absorption properties were improved in high frequency. The filling ratio of carbon black as well as the thickness of samples had influence on the absorption properties. The lowest reflection loss of-10.6 dB was obtained at 18 GHz of 5wt.% carbon black filled cement with thickness of 20mm. The new material can be used for building indoor electromagnetic radiation protection.

Electromagnetic Wave Absorbing Properties of Glass Fiber Reinforced Cement Composites with Special-Shaped Structure Surfaces

2013 ◽  
Vol 401-403 ◽  
pp. 614-618
Author(s):  
Yue Fang Zhang ◽  
Wan Jun Hao ◽  
Bao Yi Li ◽  
Yu Ping Duan ◽  
Shun Hua Liu
Keyword(s):  
Electromagnetic Wave ◽  
Glass Fiber ◽  
Building Materials ◽  
Impedance Matching ◽  
Cement Composites ◽  
Absorption Property ◽  
Frequency Range ◽  
Glass Fiber Reinforced ◽  
New Material ◽  
Reinforced Cement

In order to reach high electromagnetic wave absorption property, here we developed a cement composites building materials. Special-shaped structure surfaces have been designed to make the continuity change of impedance and increase the incident times for electromagnetic wave. Different ratio of flexible glass fiber were introduced to adjust the impedance matching characteristics of the composites and to attenuate the incident wave by scattering. As the concentration of 9% glass fiber and the surface of rectangle, the reflectivity reached the highest in the absorber with 20mm thickness. the lowest reflection loss of-15.8 dB was obtained at 8.9GHz, and the effective absorption bandwidth (less than-8 dB) reached 12 GHz in the frequency range of 1.7~18 GHz. The new material can be used for building indoor electromagnetic radiation protection.

Magnetic carbon nanofibers containing uniformly dispersed Fe/Co/Ni nanoparticles as stable and high-performance electromagnetic wave absorbers

2014 ◽  
Vol 2 (40) ◽  
pp. 16905-16914 ◽  
Author(s):  
Jun Xiang ◽  
Jiale Li ◽  
Xionghui Zhang ◽  
Qin Ye ◽  
Jiahuan Xu ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Carbon Nanofibers ◽  
High Performance ◽  
Ni Nanoparticles ◽  
Absorption Properties ◽  
Electromagnetic Wave Absorption ◽  
Wave Absorption ◽  
Magnetic Carbon ◽  
Ku Band

Magnetic carbon nanofibers containing uniformly dispersed Fe/Co/Ni nanoparticles (CNF–M) exhibit excellent electromagnetic wave absorption properties from the C-band to the Ku-band.

scholarly journals The Electromagnetic Wave Absorption Performance and Mechanical Properties of Cement-Based Composite Material Mixed with Functional Aggregates with High Fe2O3 and SiC

2021 ◽  
Vol 31 (4) ◽  
pp. 249-255
Author(s):  
Zuoqun Zhang ◽  
Chaoshan Yang ◽  
Hua Cheng ◽  
Xiaohan Huang ◽  
Yuhao Zhu
Keyword(s):  
Composite Material ◽  
Electromagnetic Wave ◽  
Electromagnetic Waves ◽  
Building Materials ◽  
Magnetic Loss ◽  
Frequency Range ◽  
Electromagnetic Wave Absorption ◽  
Wave Absorption ◽  
Test Board ◽  
Absorption Performance

Now there’re many researches on the electromagnetic radiation protection function of the cement-based electromagnetic wave absorbing materials, such materials have been widely used in various types of buildings. This paper proposed an idea for preparing a cement-based composite material by mixing functional aggregates with high content of Fe2O3 and SiC, that is, adding Fe3O4 powder and nano-SiC of different contents in the clay, and then sintering at 1190℃; the prepared aggregates showed obvious magnetic loss and dielectric loss to electromagnetic waves, and the numerical tube pressure could reach 16.83MPa. The double-layer reflectivity test board made of functional aggregates showed excellent electromagnetic wave absorption performance, its reflection loss was less than -10dB in the frequency range of 8~18GHz (corresponding to energy absorption greater than 90% EM), and its maximum RL reached -12.13dB. In addition, the compressive strength of the cement-based composite material at the age of 28 days reached 50.1 MPa, which can meet the strength requirements of building materials.

High-performance electromagnetic wave absorption of FeNi/N, S-codoped carbon composites in 2–40 GHz

Carbon ◽  
2021 ◽  
Vol 174 ◽  
pp. 201-213
Author(s):  
Cuiping Li ◽  
Guobo Chen ◽  
Weiting Jiang ◽  
Xiaohui Jiang ◽  
Xuefeng Yan
Keyword(s):  
Electromagnetic Wave ◽  
High Performance ◽  
Carbon Composites ◽  
Electromagnetic Wave Absorption ◽  
Wave Absorption
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