Facile Synthesis and Microwave-Absorption Properties of Organic–Inorganic CoFe2O4/Polyaniline Nanocomposites with Embedded Structure

2020 ◽  
Vol 20 (3) ◽  
pp. 1756-1764 ◽  
Author(s):  
Peng Chen ◽  
Lin-Wen Jiang ◽  
Shan-Shan Yang ◽  
Hong-Bing Chen ◽  
Jun He ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
Oxidative Polymerization ◽  
Sol Gel ◽  
Combustion Process ◽  
Interfacial Polarization ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
Auto Combustion ◽  
Embedded Structure

Organic–inorganic CoFe2O4/polyaniline (CoFe2O4/PA) nanocomposites with embedded structures were synthesized by combining the sol–gel auto-combustion process and in-situ oxidative polymerization. The phases and morphologies of the prepared samples were identified. The pure CoFe2O4 samples exhibited inferior microwave-absorption properties in a frequency range of 2–18 GHz. Upon the incorporation of PA, the formed CoFe2O4/PA nanocomposites exhibited rather good absorption performances. When the sample thickness was 2.5 mm, the maximum reflection loss (RL) reached -22.3 dB, while the RL below -10 dB corresponded to the range of 11.0–17.1 GHz, which contains almost the entire Ku-band, making the structure promising for commercial and military applications. A physical model was employed to explain the effects of the embedded structure on the microwave-absorption performances. The excellent microwave-absorption performances could be attributed to the interfacial polarization and repeated reflection of the microwaves inside the CoFe2O4/PA composite.

Microwave Absorption Properties of BaFe12O19 Prepared in Different Temperature with Polyaniline Nanocomposites

2017 ◽  
Vol 1142 ◽  
pp. 211-215 ◽  
Author(s):  
Wang Jun Feng ◽  
Xing Zhao ◽  
Wen Qian Zheng ◽  
Jun Tao Gang ◽  
Yue Cao ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
Reflection Loss ◽  
In Situ Polymerization ◽  
Sol Gel ◽  
Ftir Spectra ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
Result Show ◽  
Absorbing Material

The BaFe12O19 nanoparticles was prepared by sol-gel method in different temperature (750°C,850°Cand 950°C), and then BaFe12O19/polyaniline nanocomposites was synthesized by in situ polymerization. The XRD, FTIR spectra, SEM and vector network analyzer were used to analyze the "" chemical component, morphology and microwave absorption property of the nanocomposites. The result show that BaFe12O19 can be generated at 750°C without any impurity ,and its size increased with increase of calcination temperature.BaFe12O19 nanoparticle was coated with polyaniline partially, and we can get it have interaction with polyaniline through FTIR spectra. While the ferrite calcined at 850°C,the thickness of the absorbing material is 4.5mm,the nanocomposites have the largest reflection loss of-17.6 dB at 6 GHz,and its reflection loss values less than−10 dB in the range of 5-7.4GHz.

PREPARATION AND ELECTROMAGNETIC PROPERTIES OF BaFe12O19–Ni0.8Zn0.2Fe2O4/POLYPYRROLE COMPOSITE FILM

NANO ◽  
2013 ◽  
Vol 08 (02) ◽  
pp. 1350022
Author(s):  
YAN WANG ◽  
YING HUANG ◽  
QIUFEN WANG ◽  
QIAN HE
Keyword(s):  
Composite Film ◽  
Microwave Absorption ◽  
Sulfonic Acid ◽  
Oxidative Polymerization ◽  
Sol Gel ◽  
Electromagnetic Properties ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
Benzene Sulfonic Acid ◽  
Polypyrrole Composite

BaFe12O19 – Ni0.8Zn0.2Fe2O4 /Polypyrrole composite film [including three doping acids, dodecyl benzene sulfonic acid (DBSA), camphor sulfonic acid (CSA) and p-toluenesulfonic acid (TSA)] was prepared by sol–gel method and in situ chemical oxidative polymerization. The structure, morphologies, conductivities, magnetic properties and microwave absorption properties of the composite film were characterized by using XRD, FESEM, FTIR, Four-probe tester, VSM and Vector network analyzer. The results show that the conductivity of acid-doped Polypyrrole composite film is higher than that of pure Polypyrrole composite film. The saturation magnetization (Ms) and remanent magnetization (Mr) of the composite film are lower than those of BaFe12O19 – Ni0.8Zn0.2Fe2O4 film. However, the electromagnetic properties are in the contrary. The microwave absorption properties of the composite film are much better than those of BaFe12O19 – Ni0.8Zn0.2Fe2O4 , which mainly depends on the increasing of the dielectric loss. A minimum reflection loss of the DBSA-doped composite film is −17.6 dB at 9.3 GHz with the thickness at 3.0 mm.

Synthesis, Characterization, and Microwave Absorption Properties of SrFe12O19 Ferrites and FeNi3 Nanoplatelets Composites

2010 ◽  
Vol 148-149 ◽  
pp. 893-896 ◽  
Author(s):  
Ze Yang Zhang ◽  
Xiang Xuan Liu ◽  
You Peng Wu
Keyword(s):  
Electron Microscopy ◽  
Microwave Absorption ◽  
Composite Coatings ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Absorption Properties ◽  
Filling Fraction ◽  
Microwave Absorption Properties ◽  
Phase Reduction ◽  
Transmission Electron

M-typical SrFe12O19 ferrites and FeNi3 nanoplatelets were successfully prepared by the sol-gel method and solution phase reduction method, respectively. The crystalline and morphology of particles were studied by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The composite coatings with SrFe12O19 ferrites and FeNi3 nanoplatelets in polyvinylchloride matrix were prepared. The microwave absorption properties of these coatings were investigated in 2-18GHz frequency range. The results showed that the M-typical SrFe12O19 ferrites and FeNi3 nanoplatelets were obtained and they presented irregular sheet shapes. With the increase of the coating thickness, the absorbing peak value moves to the lower frequency. The absorbing peak values of the wave increase along with the increasing of the content of FeNi3 nanoplatelets filling fraction. When 40% SrFe12O19 ferrites is doped with 20% mass fraction FeNi3 nanoplatelets to prepare composite with 1.5mm thickness, the maximum reflection loss is -24.8 dB at 7.9GHz and the -10 dB bandwidth reaches 3.2GHz.

Magnetization and Microwave Absorption Properties of La0.67 Sr0.33 MnO3 with Different Particle Size

2011 ◽  
Vol 374-377 ◽  
pp. 1541-1544 ◽  
Author(s):  
Yu Lan Cheng ◽  
Ping Xia ◽  
Ke Xiang Wei ◽  
Quan Bai
Keyword(s):  
Particle Size ◽  
Sinter Temperature ◽  
Microwave Absorption ◽  
Reflection Loss ◽  
Sol Gel ◽  
Frequency Range ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
Measured Frequency Range ◽  
Maximum Reflection Loss

La 0.67 Sr 0.33 MnO 3 particles with different particle size have been prepared by sol-gel method. The structure, magnetization and microwave absorption properties have been investigated. The results show that the particle size can be controlled by sinter temperature. The peaks of the maximum reflection loss (RL) move to higher frequency regions with increasing particle size. The value of the maximum RL is -32 dB at 10.2GHz with a particle size of 58.5nm. The bandwidth with a RL exceeding -8dB reached 1.6GHz in the whole measured frequency range, suggesting that La 0.67 Sr 0.33 MnO 3 particles are promising for application as a wideband and strong absorption building microwave absorber.

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