Microwave absorbing paints and sheets based on carbonyl iron and polyaniline: measurement and simulation of their properties

Folgueras, Luiza de Castro; Alves, Mara Lisa; Rezende, Mirabel Cerqueira

doi:10.5028/jatm.2010.02016370

Cited by 76 publications

(38 citation statements)

References 27 publications

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“…For definition 63,64 , the real relative permittivity values (ε = ε' -jε") are always higher than the unit. A material which presents value zero of dielectric loss it will have the values of the permittivity complex parameters ε'=1 e ε"=0.…”

Section: Electromagnetic Propertiesmentioning

confidence: 99%

“…SEM analyses (Figures 1 and 2) show the presence of NTC agglomerates after the dispersion in the resin. According to literature 63,64 these agglomerates act as electric conduction islands and favor the interaction of the electromagnetic wave with the material. It is also observed that the RAM samples evaluated behave as a narrow band absorber (resonance peak in the range of 9.5 and 11 GHz) in the evaluated frequency range (8.2 to 12.4 GHz).…”

Section: Electromagnetic Propertiesmentioning

confidence: 99%

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Nanostructured composites based on carbon nanotubes and epoxy resin for use as radar absorbing materials

et al. 2013

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Nanostructured polymer composites have opened up new perspectives for multifunctional materials. In particular, carbon nanotubes (CNTs) present potential applications in order to improve mechanical and electrical performance in composites with aerospace application. The combination of epoxy resin with multiwalled carbon nanotubes results in a new functional material with enhanced electromagnetic properties. The objective of this work was the processing of radar absorbing materials based on formulations containing different quantities of carbon nanotubes in an epoxy resin matrix. To reach this objective the adequate concentration of CNTs in the resin matrix was determined. The processed structures were characterized by scanning electron microscopy, rheology, thermal and reflectivity in the frequency range of 8.2 to 12.4 GHz analyses. The microwave attenuation was up to 99.7%, using only 0.5% (w/w) of CNT, showing that these materials present advantages in performance associated with low additive concentrations.

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Section: Electromagnetic Propertiesmentioning

confidence: 99%

Section: Electromagnetic Propertiesmentioning

confidence: 99%

Nanostructured composites based on carbon nanotubes and epoxy resin for use as radar absorbing materials

et al. 2013

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“…A segunda etapa correspondente à degradação da cadeia polimérica inicia-se em torno de 190 °C. Este valor de temperatura de início de degradação é favorável para o processamento de absorvedores de uso aeronáutico, pois atende aos requisitos deste setor, que necessita de materiais estáveis até 120 °C [32] . Adicionalmente, verifica-se uma etapa adicional de perda de massa, entre 190 a 250 °C, para a amostra de PPi-SO 4 atribuída à evolução do SO 2 , conforme também observado na literatura [29,30] .…”

Section: Resultsunclassified

Síntese do polipirrol com surfactantes aniônicos visando aplicações como absorvedores de micro-ondas

Campos¹,

Faez²,

Rezende³

2014

Polímeros

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Resumo: Neste trabalho diferentes amostras de polipirrol (PPi) foram sintetizadas variando a combinação dos oxidantes FeCl 3 e Fe 2 (SO 4 ) 3 e dos surfactantes docecilbenzenosulfonato de sódio (DBSNa) e ácido dodecilbenzenosulfônico (DBSA). Análises por espectroscopia na região do infravermelho não apresentam diferenças significativas na estrutura química das amostras de PPi sintetizadas. No entanto, análises termogravimétricas, de condutividade elétrica e de difração de raios X mostram que os surfactantes aniônicos favorecem a obtenção de amostras mais estáveis termicamente, condutoras e ordenadas cristalograficamente. Medidas de refletividade de blendas de PPi com resina epóxi, na faixa de 8 a 12 GHz, mostram valores de atenuação de micro-ondas de até 95% da radiação incidente. Palavras-chave: Polipirrol, absorvedores de micro-ondas, síntese. Synthesis of Polypyrrole with Anionic Surfactants Targeting Applications such as Microwave AbsorbersAbstract: In this work different samples of polypyrrole (PPy) were synthesized varying the combination of FeCl 3 and Fe 2 (SO 4 ) 3 as oxidant agents and sodium dodecylbenzenesulfonate (DBSNa) and dodecylbenzenesulfonic acid (DBSA) as surfactants. Infrared spectroscopy analyses showed no significant differences in the chemical structures of synthesized PPy samples. However, thermogravimetric, electrical conductivity and X-ray diffraction analyses showed that the anionic surfactants favored the preparation of samples which are more thermally stable, conducting and with a more ordered crystallographic structure. Reflectivity measurements of PPy/epoxy resin blends, in the frequency range from 8 to 12 GHz, showed microwave attenuation up to 95% of the incident radiation.

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“…Because of its unique micro structures, Carbonyl iron powder (CIP)is noted for its excellent microwave feature at GHz range [15]. To this end, a homemade absorber was manufactured by mixing proper weight percentage of carbonyl iron powder and silicon polymer.…”

Section: Measurement Of Materials Electromagnetic Constantsmentioning

confidence: 99%

Analysis and Design of an Uhf Rfid Metal Tag Using Magnetic Composite Material as Substrate

Kuo¹,

Hsu²,

Hung³

2010

PIER B

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Abstract-Using magnetic composite material as the substrate for RFID metal tag has several advantages over conventional metal tags, such as flexibility and miniaturized size. In this paper, the radiation intensity contributed by a half-wave dipole is derived based on the result of an ideal Hertzian dipole, which leads to a simple relation for thin substrate. Later on, the material constants of two materials are measured and the one capable of generating greater radiation intensity is used in the course of antenna design. A primitive pattern design demonstrates the metal tag has a satisfactory 2.7 m reading range, and a dimension of 80 × 22 × 2 mm 3 .

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Microwave absorbing paints and sheets based on carbonyl iron and polyaniline: measurement and simulation of their properties

Cited by 76 publications

References 27 publications

Nanostructured composites based on carbon nanotubes and epoxy resin for use as radar absorbing materials

Nanostructured composites based on carbon nanotubes and epoxy resin for use as radar absorbing materials

Síntese do polipirrol com surfactantes aniônicos visando aplicações como absorvedores de micro-ondas

Analysis and Design of an Uhf Rfid Metal Tag Using Magnetic Composite Material as Substrate

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