Conductive-network enhanced microwave absorption performance from carbon coated defect-rich Fe2O3 anchored on multi-wall carbon nanotubes

Carbon ◽  
2019 ◽  
Vol 155 ◽  
pp. 298-308 ◽  
Author(s):  
Lei Wang ◽  
Xuefeng Yu ◽  
Xiao Li ◽  
Jie Zhang ◽  
Min Wang ◽  
...  
Author(s):  
Dawei Liu ◽  
Yunchen Du ◽  
Ping Xu ◽  
Fengyuan Wang ◽  
Yahui Wang ◽  
...  

The enhanced microwave absorption performance of composites benefits from simultaneous rational microstructure design and chemical composition modulation.


2017 ◽  
Vol 9 (3) ◽  
pp. 2973-2983 ◽  
Author(s):  
Na Li ◽  
Gui-Wen Huang ◽  
Yuan-Qing Li ◽  
Hong-Mei Xiao ◽  
Qing-Ping Feng ◽  
...  

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Xiao Li ◽  
Wenbin You ◽  
Chunyang Xu ◽  
Lei Wang ◽  
Liting Yang ◽  
...  

Highlights Benefiting from the possible “seed-germination” effect, the “seeds” Ni2+ grow into “buds” Ni nanoparticles and “stem” carbon nanotubes (CNTs) from the enlarged “soil” of MXene skeleton. Compared with the traditional magnetic agglomeration, the MXene-CNTs/Ni hybrids exhibit the highly spatial dispersed magnetic architecture. 3D MXene-CNTs/Ni composites hold excellent microwave absorption performance (−56.4 dB at only 2.4 mm). Abstract Ti3C2Tx MXene is widely regarded as a potential microwave absorber due to its dielectric multi-layered structure. However, missing magnetic loss capability of pure MXene leads to the unmatched electromagnetic parameters and unsatisfied impedance matching condition. Herein, with the inspiration from dielectric-magnetic synergy, this obstruction is solved by fabricating magnetic CNTs/Ni hetero-structure decorated MXene substrate via a facile in situ induced growth method. Ni2+ ions are successfully attached on the surface and interlamination of each MXene unit by intensive electrostatic adsorption. Benefiting from the possible “seed-germination” effect, the “seeds” Ni2+ grow into “buds” Ni nanoparticles and “stem” carbon nanotubes (CNTs) from the enlarged “soil” of MXene skeleton. Due to the improved impedance matching condition, the MXene-CNTs/Ni hybrid holds a superior microwave absorption performance of − 56.4 dB at only 2.4 mm thickness. Such a distinctive 3D architecture endows the hybrids: (i) a large-scale 3D magnetic coupling network in each dielectric unit that leading to the enhanced magnetic loss capability, (ii) a massive multi-heterojunction interface structure that resulting in the reinforced polarization loss capability, confirmed by the off-axis electron holography. These outstanding results provide novel ideas for developing magnetic MXene-based absorbers.


NANO ◽  
2015 ◽  
Vol 10 (05) ◽  
pp. 1550070 ◽  
Author(s):  
B. B. Zhang ◽  
P. F. Wang ◽  
J. C. Xu ◽  
Y. B. Han ◽  
H. X. Jin ◽  
...  

Owing to the unique microstructure and the excellent dielectric properties, carbon nanotubes (CNTs) were decorated with CoFe 2 O 4 nanoparticles to synthesize the CoFe 2 O 4/CNTs nanocomposites by the solvothermal method. The phase structure, morphology, magnetic properties and microwave absorption performance of the as-prepared CoFe 2 O 4/CNTs were characterized and discussed by X-ray diffraction (XRD), thermal gravity analysis (TGA), transmission electron microscope (TEM), vibrating sample magnetometer (VSM) and vector network analyzer (VNA). All results indicated that the diameter of CoFe 2 O 4 nanoparticles decorating on the surface of CNTs increased with the solvothermal temperature. CoFe 2 O 4/CNTs prepared at 180°C, 200°C and 220°C exhibited superparamagnetism, while the other samples presented ferromagnetism at room temperature. And with the increasing solvothermal temperature, the saturation magnetization and coercivity increased up to 72 emu/g and 2000 Oe for the sample prepared at 260°C (S-26). And the reflection loss of CoFe 2 O 4/CNTs nanocomposites increased with the solvothermal temperature up to -15.7 dB for S-26 with the bandwidth of 2.5 GHz.


Author(s):  
Huajie Mao ◽  
Xuliang Zhong ◽  
Xiaorui Liu ◽  
Wei Guo ◽  
Danfeng Zhou ◽  
...  

Abstract In order to study the conductive and microwave absorption performance of multi-dimensional multiphase filler conductive foam composites, carbon nanotubes (CNTs)/carbon black (CB)/polymethyl methacrylate (PMMA) nanocomposites with different porosity were fabricated via supercritical carbon dioxide (ScCO2) one-step physical constraint foaming technology.The effects of filler component and porosity on the conductivity and absorbing properties of CNTs/PMMA/CB composite foam were studied. The Monte-Carlo method was used to study the percolation of composites and the effect of introduced microcells on the conductive network of multi-dimensional fillers.The results revealed that the volume conductivity of CNTs(3 vol%)/PMMA composites increased from 0.88 S/m to 3.31 S/m after the addition of 1 vol% CB. CNTs and CB had obvious synergistic effect on improving the conductivity of the composites, and the microwave absorption efficiency rose from 12.6 dB to 17.2 dB. With the increase of porosity, the electromagnetic wave absorption peak of CNTs/CB/PMMA composite foam moved to low frequency, while the conductivity showed a first rise and then a decline. The simulated percolation probability obtained by representative volume element (RVE) with different porosity also showed a similar trend, which turned out that with the increase of porosity, the effect of microcells on the convertion of conductive network construction from promoting to inhibiting.


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