Fabrication of multi-functional PVDF/RGO composites via a simple thermal reduction process and their enhanced electromagnetic wave absorption and dielectric properties

RSC Advances ◽  
2014 ◽  
Vol 4 (38) ◽  
pp. 19594-19601 ◽  
Author(s):  
Xiao-Juan Zhang ◽  
Guang-Sheng Wang ◽  
Wen-Qiang Cao ◽  
Yun-Zhao Wei ◽  
Mao-Sheng Cao ◽  
...  

The PVDF/RGO composites synthesized by a thermal reduction process exhibit high values of reflection loss and excellent dielectric properties with low filler loading.

Author(s):  
Bin Du ◽  
Mei Cai ◽  
Xuan Wang ◽  
Junjie Qian ◽  
Chao He ◽  
...  

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.


2014 ◽  
Vol 1035 ◽  
pp. 520-523 ◽  
Author(s):  
Ye Sun ◽  
Yue Fang Zhang ◽  
Wan Jun Hao

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.


2017 ◽  
Vol 2017 ◽  
pp. 1-6
Author(s):  
Bitao Fan ◽  
Qiufang Yao ◽  
Chao Wang ◽  
Ye Xiong ◽  
Qingfeng Sun ◽  
...  

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.


2017 ◽  
Vol 2 (2) ◽  
pp. 99 ◽  
Author(s):  
Nenni Nenni ◽  
Mutia Delina ◽  
Wisnu Ari Adi ◽  
Yana Taryana

Substitution of Ti+4 and Zn+2 ions on magnetic material BaFe12-xTix/2Znx/2O19 (x = 0 and 2) using the wet milling method has been performed. This research was conducted to get information the influence of Ti-Zn substitution on magnetic properties and its absorption. The magnetic material BaFe12-xTix/2Znx/2O19 is synthesized from a mixture of oxide materials, BaCO3, Fe2O3, TiO2 and ZnO. The mixture was milled for 5 hours, dried at 1000C then sintered at 10000C for 5 hours. The refinement result of the X-ray diffraction pattern shows that the sample has single phase BaFe12O19 with doping concentration of x = 0 and 2. The hysteresis curve shows that coercivity field value decreased in the sample with doping concentration of x = 2. The result of electromagnetic wave absorption shows that the substituted sample with Ti+4 and Zn+2 ions (doping concentration x = 2) has the highest absorption peak at a frequency of 11,2 GHz with reflection loss value (RL) of -24,3 dB. Electromagnetic wave absorption reaches 94% with sample thickness is about 1,0 mm. Therefore, the magnetic material BaFe12-xTix/2Znx/2O19 (x = 2) can be used for application of the electromagnetic wave absorber. Keywords: Substitution, BaFe12-xTix/2Znx/2O19, wet milling, reflection loss, electromagnetic wave absorber.


2010 ◽  
Vol 143-144 ◽  
pp. 1051-1055
Author(s):  
Zhang Hong Tang ◽  
Wang Qun

In this paper, a method to simulate the absorbing effectiveness of spherical particle absorber is presented and the effect of the diameter of spheres, the number of layer and the stack modes of sphere particle to the absorbing effectiveness were also researched. Basing on the simulation results, an optimal spherical particle absorber was designed. The absorber has 3 layers with 1 mm, 2 mm and 4 mm spheres stacked on each layer respectively. Simulation result shows that the optimal absorber achieves a maximum reflection loss of -15 dB and the bandwidth being lower than -5 dB is more than 16 GHz in 1~18 GHz.


2020 ◽  
Author(s):  
Yun Qiu ◽  
Haibo Yang ◽  
Liang Ma ◽  
Ying Lin ◽  
Hanwen Zong ◽  
...  

Abstract Nickel carbon composite with carbon nanotubes (Ni-C/CNTs) has been fabricated by pyrolysis the mixture of nickel-based metal organic framework (Ni-MOF) and melamine. The resultant Ni-C/CNTs composite is assembled from one-dimensional (1D) CNTs and three dimensional (3D) spherical Ni-C composite. Besides, the Ni-C/CNTs composite contains abundant nitrogen(N) dopants that contributes to defect dipole polarization. The diameter and length of CNTscan beeffected by changing the mass ratio of Ni-MOF and melamine. The optimizedNi-C/CNTs composite exhibits reflection loss of -55.1 dB at 10.56 GHz, and the effective absorbing bandwidth (reflection loss < -10 dB) is 11.2 GHz (6.0-17.2 GHz)with the thickness range of 1.5-4.0 mm, when the mass ratio of Ni-MOF: melamine is 1: 2. These results indicate that the mixed 1D-3D hierarchical architecture synergistically improves electromagnetic wave absorption properties. This strategy willcontribute for fabricating the carbon hybrid network consisting of metal organic frameworks derived metal/carbon hybrid and CNTs for electromagnetic wave absorption.


2012 ◽  
Vol 549 ◽  
pp. 665-669 ◽  
Author(s):  
Gui Mei Shi ◽  
Wei Min Sun ◽  
Da Wei Lu ◽  
Shu Lian

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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