Preparation and Electromagnetic Properties of CIP/SiO2/PANI Composites

2013 ◽  
Vol 834-836 ◽  
pp. 187-190
Author(s):  
Ming Ming Wang ◽  
Zhong Lun Zhang ◽  
Wan Jun Hao ◽  
Guo Yan Hou ◽  
Zhi Jun Xin ◽  
...  
Keyword(s):  
Dielectric Loss ◽  
In Situ Polymerization ◽  
Magnetic Loss ◽  
Electromagnetic Properties ◽  
Complex Permeability ◽  
Core Shell ◽  
Network Analyzer ◽  
Frequency Range ◽  
Xrd Patterns

CIP particles first were coated with SiO2 shell by the Stober process , then grafted the polyaniline by in-situ polymerization to prepare CIP/SiO2/PANI core-shell composites. The CIP/SiO2/PANI composites are composed the dielectric loss properties with the the magnetic loss properties, the morphologystructure and electromagnetic properties are characterized by SEMXRD and vector network analyzer, respectively. It is observed that SiO2 and PANI are on the surface of CIP particles, XRD patterns further confirm that the CIP/SiO2/PANI composites are synthesized successfully, and that interaction between components exist in the polymerization. In comparison with CIP, the complex permittivity of CIP/SiO2/PANI composites have certain enhancement in 2-18GHz frequency range, but it has a very small impact on the complex permeability.

Preparation of CIP/SiO2/PANI Composites and Design of Electromagnetic Wave Absorption Coating in X-Band

2013 ◽  
Vol 846-847 ◽  
pp. 1905-1910
Author(s):  
Ming Ming Wang ◽  
Wan Jun Hao ◽  
Zhong Lun Zhang ◽  
Guo Yan Hou ◽  
Zhi Jun Xin ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
High Performance ◽  
In Situ Polymerization ◽  
Magnetic Loss ◽  
Complex Permeability ◽  
Frequency Range ◽  
Sem Image ◽  
X Band ◽  
Xrd Patterns

CIP particles first have been coated with SiO2 shell by a Stober process , then grafted the polyaniline by in-situ polymerization to prepare CIP/SiO2/PANI core-shell composites, and the composites are composed the dielectric loss properties with the magnetic loss properties. It is observed that PANI are on the surface of CIP/SiO2 particles from the SEM image, XRD patterns further confirm that the CIP/SiO2/PANI composites are synthesized successfully. In comparison with CIP, the complex permittivity of CIP/SiO2/PANI composites have certain enhancement in 8-12 GHz frequency range, but it has a very small impact on the complex permeability. On the basis of the Electromagnetic Wave Absorbing Theory, the composites could prepare high-performance absorbing coating based on λ/4 type design, and the coating is below-10dB in the whole X-band, which could be used for architectural space electromagnetic radiation protection.

Preparation and Electromagnetic Properties of Poly(o-Toluidine)-BaAl2Fe10O19 Composites

2011 ◽  
Vol 295-297 ◽  
pp. 249-255
Author(s):  
Ke Yu Chen ◽  
Meng Xi Sun ◽  
Liang Chao Li ◽  
Feng Xu ◽  
Qiu Shi Xiao
Keyword(s):  
Electromagnetic Wave ◽  
Dielectric Loss ◽  
In Situ Polymerization ◽  
Magnetic Loss ◽  
Electromagnetic Property ◽  
Electromagnetic Properties ◽  
Intrinsic Properties ◽  
Electromagnetic Wave Absorption ◽  
Testing Techniques

The poly(o-toluidine)/BaFe10Al2O19 (POT/BFA) composites were synthesized by in-situ polymerization of o-toluidine in the presence of BaFe10Al2O19 particles. The structure, composition and morphology and electromagnetic property of the obtained samples were characterized by means of modern testing techniques. The results indicated that BFA particles were coated effectively by POT polymer chain and some interactions between POT and BFA particles were existed in the composites. The conductivity and saturation magnetization of POT/BFA composites were smaller than those of pure polymers and pure BFA respectively. The POT/BFA composites had excellent magnetic loss (μ′′) and dielectric loss (ε′′) in the range of 1 MHz~3 GHz because of their intrinsic properties and synergistic effect between components. Hence, they could be recommended as candidates for electromagnetic wave absorption and shielding materials.

scholarly journals Preparation and Conductive and Electromagnetic Properties of Fe3O4/PANI Nanocomposite via Reverse In Situ Polymerization

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Di Zhang ◽  
Huaiyin Chen ◽  
Ruoyu Hong
Keyword(s):  
In Situ Polymerization ◽  
Rapid Development ◽  
Chloroform Solution ◽  
Electromagnetic Properties ◽  
Network Analyzer ◽  
The Novel ◽  
Electromagnetic Devices ◽  
Ft Ir ◽  
Polymerization Method

In this paper, the magnetite/polyaniline (PANI) nanocomposite was prepared by the novel reverse in situ polymerization method. Fe3O4 magnetic nanoparticles were synthesized in situ in PANI chloroform solution to form a suspension containing the Fe3O4/PANI nanocomposite. It overcame the disadvantage of oxidation of the Fe3O4 by the oxidant in conventional method. The Fe3O4/PANI chloroform suspension and the Fe3O4/PANI powder were characterized by FT-IR, TEM, XRD, vibrating sample magnetometer, Gouy magnetic balance, conductivity meter, and vector network analyzer. It is demonstrated that the Fe3O4/PANI suspension has a good electrical conductivity that is up to 2.135 μS/cm at the optimal ratio of reactants. The Fe3O4 nanoparticles are well dispersed in the PANI network with a particle size of about 10 nm. Fe3O4/PANI powder has high saturation magnetization and magnetic susceptibility, as well as a broad application prospect in the field of electromagnetic devices. The Fe3O4/PANI powder exhibits an excellent microwave absorption behavior, which can be an outstanding candidate for the rapid development of broadband shielding materials.

Electromagnetic Properties of Polyaniline Co-Doped with CSA and Ni2+

2011 ◽  
Vol 194-196 ◽  
pp. 2268-2271
Author(s):  
Shi Bu Zhu ◽  
Man Jiang ◽  
An Zhao ◽  
Wei Wei ◽  
Zuo Wan Zhou
Keyword(s):  
Room Temperature ◽  
Magnetic Loss ◽  
Microwave Frequency ◽  
Electromagnetic Properties ◽  
Good Effect ◽  
Network Analyzer ◽  
Wide Range ◽  
Absorbing Material ◽  
Co Doped

In this work, polyaniline co-doped with (IS)-(+)-10-camphorsulfonic acid (D-CSA) and Ni2+was synthesized viain situpolymerization. The structure, conductivity and electromagnetic parameters of the resulting polyaniline were characterized by FTIR, SZ82 digital multimeter and AV3618 network analyzer. The conductivity of polyaniline at room temperature increases with increasing of Ni2+loading. Moreover, the resulting polyaniline co-doped with Ni2+displays obvious magnetic loss at the microwave frequency. So, we suppose that this conducting polymer can be used as microwave absorbing material with wide-range and good effect.

Microwave Absorption Properties of Fe3O4-Graphene Nanohybrids

2017 ◽  
Vol 268 ◽  
pp. 297-301 ◽  
Author(s):  
Yau Thim Ng ◽  
Wei Kong ◽  
Sivanesan Appadu ◽  
Ing Kong
Keyword(s):  
Microwave Absorption ◽  
Magnetic Loss ◽  
Impedance Matching ◽  
Low Frequency ◽  
Electromagnetic Properties ◽  
Frequency Range ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
In Situ Deposition

Magnetite (Fe3O4)-graphene nanohybrids having three different weight ratios of magnetite to graphene were synthesized by a facile in-situ deposition method. The combination of dielectric properties of graphene and magnetic properties of magnetite makes the nanohybrids an ideal choice of material for microwave absorption applications. In regards to that, the electromagnetic properties and microwave absorbing characteristics were investigated in a frequency range of 1-18 GHz. The reflection loss (RL) reaches a minimum of-40.44 dB at 6.84 GHz with a thickness of 7 mm for the sample containing 73 wt·% of Fe3O4. The bandwidth corresponding to the RL below-10 dB is 7.05 GHz. The as-prepared Fe3O4-graphene nanohybrids showed good microwave absorption ability in the low frequency band (C-band) which can be ascribed to improved impedance matching characteristics, enhanced interfacial polarizations as well as the magnetic loss contributions. Moreover, the frequency related to minimum RL could be tuned by varying the weight ratios of magnetite to graphene.

Preparation and Performance of Chiral Polyaniline/Cobalt Ferrite Composites

2016 ◽  
Vol 852 ◽  
pp. 342-345
Author(s):  
Juan Bi Li ◽  
Di Qiong Hu ◽  
Yu Huan Wang ◽  
Liang Chao Li ◽  
Yan Ding
Keyword(s):  
Dielectric Loss ◽  
Cobalt Ferrite ◽  
In Situ Polymerization ◽  
Optical Rotation ◽  
Magnetic Loss ◽  
And Performance ◽  
Ferrite Composites ◽  
Co Precipitation ◽  
Polymerization Method

The cobalt ferrite and chiral polyaniline/cobalt ferrite composites were synthesized by co-precipitation and in-situ polymerization method, respectively. The crystal structure and composition, electrical conductivity, optical rotation, dielectric loss and magnetic loss of the as-prepared samples were researched. It was found that the optical rotation (levorotation) of composites is less than that of chiral polyaniline (L-PANI), and increased with the increasing of L-PANI content. The conductivity of the composites with a mass ratio of L-PANI to cobalt ferrite above 0.4 was better than of pure L-PANI, and their dielectric loss was in accordance with the conductivity in variation trend.

Influences of Nd3+ Ions Substitution on the Structure and Electromagnetic Properties of the Nanocrystalline Co0.5Zn0.5Fe2O4 Ferrite

2011 ◽  
Vol 194-196 ◽  
pp. 524-528
Author(s):  
Rui Ting Ma ◽  
San Kuan Chen ◽  
Gang Zhang
Keyword(s):  
Dielectric Loss ◽  
Loss Tangent ◽  
Magnetic Loss ◽  
Electromagnetic Properties ◽  
Complex Permeability ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Polyacrylamide Gel Method ◽  
Average Size

The spinel nanocrystalline Co0.5Zn0.5Nd0.05Fe1.95O4 ferrite was prepared by polyacrylamide gel method. Influences of Nd3+ ions substitution on the microstructural and electromagnetic properties for the Co0.5Zn0.5Fe2O4 ferrites had been systematically investigated by X-ray diffraction (XRD), transmission electron microscope (TEM) and wave-guide method. The results showed that the Nd3+ ions can replace Fe3+ ions and adjust lattice parameters. The average size of the Co0.5Zn0.5Fe2O4 and Co0.5Zn0.5Nd0.05Fe1.95O4 particles were identified to be about 50nm and 60nm by TEM, respectively. The complex permittivity (=ε′-jε″) and complex permeability (=μ′-jμ″) for the composites had been measured in the frequency range of 8.2-12.4GHz. The results showed that the Co0.5Zn0.5Fe2O4 and Co0.5Zn0.5Nd0.05Fe1.95O4 ferrites had both dielectric loss and magnetic loss. The dielectric loss tangent (tgδε) and magnetic loss tangent (tgδm) for the Co0.5Zn0.5Nd0.05Fe1.95O4 ferrite were obviously higher than those of the Co0.5Zn0.5Fe2O4. The maximal value of tgδε and tgδm for the Co0.5Zn0.5Nd0.05Fe1.95O4 ferrite was around 0.30 at 12.4GHz and 0.16 at 10.8GHz, respectively.

Enhanced dielectric properties and thermostability in polyimide composites with core-shell structured polyimide@BaTiO3 nanoparticles

2021 ◽  
pp. 095400832199352
Author(s):  
Wei Deng ◽  
Guanguan Ren ◽  
Wenqi Wang ◽  
Weiwei Cui ◽  
Wenjun Luo
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Energy Density ◽  
Breakdown Strength ◽  
In Situ Polymerization ◽  
Dielectric Materials ◽  
High Energy ◽  
Amic Acid ◽  
High Energy Density ◽  
Core Shell

Polymer composites with high dielectric constant and thermal stability have shown great potential applications in the fields relating to the energy storage. Herein, core-shell structured polyimide@BaTiO3 (PI@BT) nanoparticles were fabricated via in-situ polymerization of poly(amic acid) (PAA) and the following thermal imidization, then utilized as fillers to prepare PI composites. Increased dielectric constant with suppressed dielectric loss, and enhanced energy density as well as heat resistance were simultaneously realized due to the presence of PI shell between BT nanoparticles and PI matrix. The dielectric constant of PI@BT/PI composites with 55 wt% fillers increased to 15.0 at 100 Hz, while the dielectric loss kept at low value of 0.0034, companied by a high energy density of 1.32 J·cm−3, which was 2.09 times higher than the pristine PI. Moreover, the temperature at 10 wt% weight loss reached 619°C, demonstrating the excellent thermostability of PI@BT/PI composites. In addition, PI@BT/PI composites exhibited improved breakdown strength and toughness as compared with the BT/PI composites due to the well dispersion of PI@BT nanofillers and the improved interfacial interactions between nanofillers and polymer matrix. These results provide useful information for the structural design of high-temperature dielectric materials.

Synthesis, Characterization and Properties of PANI/(La-Nd Doped BaFe12O19) Composites

2017 ◽  
Vol 727 ◽  
pp. 327-334
Author(s):  
Yan Wang ◽  
Jun Wang ◽  
Xiao Fei Zhang ◽  
Ya Qing Liu
Keyword(s):  
Sol Gel ◽  
Network Analyzer ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Structure Morphology ◽  
Xrd Patterns ◽  
Hexagonal Platelet ◽  
Peak Value ◽  
Properties Of Composites

La-Nd co-doped barium hexaferrites, Ba0.7(LamNdn)0.3Fe12O19 (D-BaM), were successfully prepared by sol-gel method. PANI / D-BaM composites were synthesized by in-situ polymerization in solution. The structure, morphology and properties of samples have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), four-probe conductivity tester and vector network analyzer. The XRD patterns showed that the crystal structure of all the samples exist as M-type phases. The SEM images revealed that the particles presented a hexagonal platelet-like morphology. The magnetic properties could be improved by substitutions of La and Nd ions. The saturation magnetization (Ms) and coercive force (Hc) increased with the change of La / Nd ratio to the maximum at La / Nd = 3:1. The doped particles have also been embedded in conductive PANI to prepare electromagnetic materials, and the conductivity kept on the order of 10-2. The microwave absorbing properties of composites at 30 MHz-6 GHz improved obviously, the peak value of reflection loss could reach-7.5 dB.

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