Improved microwave absorption in lightweight resin-based carbon foam by decorating with magnetic and dielectric nanoparticles

Kumar, Rajeev; Singh, Awantika; Chand, Mahesh; Pant, R. P.; Kotnala, R.K.; Dhawan, S. K.; Mathur, R.B.; Dhakate, Sanjay R.

doi:10.1039/c4ra01731e

Cited by 57 publications

(31 citation statements)

References 39 publications

(50 reference statements)

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“…Therefore, shielding effectiveness will be better for minimum reflection loss as less amount of EM wave will reflect back. Reflection loss (RL) of pure resin, MWCNT/EPr, and GO-MWCNT/EPr composites can be calculated by the following equations, [22,23] …”

Section: Microwave Absorption and Emi Shieldingmentioning

confidence: 99%

Combined effect of graphene oxide and MWCNTs on microwave absorbing performance of epoxy composites

Arooj

Zhao

Han

et al. 2015

Polymers for Advanced Techs

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Currently, carbon nanotube (CNT) -based composites have been considered as microwave absorbers because of the fascinating properties of CNTs. In this work, multi-walled CNTs (MWCNTs) and graphene oxide (GO) -based epoxy composites (i.e. MWCNT/EPr and GO-MWCNT/EPr), with sample thickness of 2 mm, were prepared to study microwave absorbing properties in the frequency band of 8-18 GHz. Uniform dispersion of MWCNTs in the organic solvent and polymer matrix was achieved by preparation of GO. The test for electromagnetic parameters, i.e. complex permittivity and the permeability of the samples, was carried out with vector network analyzer (VNA) using reflectiontransmission waveguides. Results showed that GO-MWCNT/EPr composites have better absorption capability than MWCNT/EPr composites. The improved reflection loss for the composites with 0.4 wt% and 0.6 wt% of GO (out of total filler loading 6 wt%) were À14.32 dB and À14.29 dB, respectively. The improvement in reflection loss and absorption bandwidth for GO-MWCNTs composites suggested that MA features are synergistically effected by GO and MWCNTs. Further skin depth and shielding effectiveness terms are studied to observe overall mechanism of electromagnetic (EM) shielding which showed that multiple reflections also play a role in EM shielding.

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Section: Microwave Absorption and Emi Shieldingmentioning

confidence: 99%

Combined effect of graphene oxide and MWCNTs on microwave absorbing performance of epoxy composites

Arooj

Zhao

Han

et al. 2015

Polymers for Advanced Techs

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“…In the past decades, more and more carbon materials and their composites are studied in the fields of microwave absorbing and electromagnetic wave shielding, such as carbon nanotubes, [14][15][16] carbon foams [17][18][19][20] and carbon fibers. [21][22] Compared with other carbon materials, RGO-based composites have preferable physical and chemical properties.…”

Section: Introductionmentioning

confidence: 99%

High‐Performance Microwave Absorption of MOF‐Derived Core‐Shell Co@N‐doped Carbon Anchored on Reduced Graphene Oxide

Liu

Wang

et al. 2019

ChemNanoMat

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Nanocomposites of MOF-derived N-doped-carbonwrapped cobalt anchored on reduced graphene oxide (Co@NC@RGO) have been successfully fabricated for use as microwave absorption materials. A unique core-shell nanostructure with cobalt nanoparticles as core and N-doped graphitized carbon as shell was grown on the surface of laminated reduced graphene oxide (RGO). An enhanced synergistic effect between magnetic and dielectric components can be readily achieved by changing the dispersion of Co@NC nanoparticles on RGO. The as-synthesized microspheres are composed of numerous nanoscale core-shell Co@NC units, which combined magnetic Co cores with intrinsically contributing magnetic loss and N-doped graphitized carbon providing a pathway for electron transfer as well as transition between magnetic Co cores and high electrical conductivity of RGO. The resulting Co@NC@RGO composites exhibit excellent reflection loss (RL) values and effective absorption bandwidths. The optimized Co@NC@RGO-3 minimum RL (RLmin) value could reach À 46.5 dB at 9.4 GHz with a thickness of 3.5 mm. Tuning the thickness from 1.5-5 mm, the effectivity absorption frequency range could achieve up to 14.3 GHz (from 3.7 to 18 GHz). The excellent microwave absorption performance may be attributed to the magnetic loss, dielectric loss and interfacial polarization.[a] L.

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“…These unique features offer great promise for usage in EMI shielding industry. The EMI shielding efficiency (SE) of a polymeric composite depends on many factors, including the filler dispersion state, characteristics of each component, composition, and thickness . The EMI SE can be enhanced by increasing the thickness and/or the filler content.…”

Section: Introductionmentioning

confidence: 99%

Facile preparation of asymmetric Ni/PVC film with controlled structure: Application as a high‐performance EMI shielding material

Zhang

Xiaoxia

Wen

2015

J of Applied Polymer Sci

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Controlling the spatial configuration of conductive fillers in thin composites by a facile strategy is critical to widely commercial use these materials for electromagnetic interference (EMI) shielding applications. In this work, a series of free-standing thin Ni/polyvinyl chloride (PVC) films with the same composition just systematically varied Ni particles dispersion states was prepared by solution casting method. The relationships between the structure and properties were also investigated. Ni particles motion was governed by evaporation and sedimentation during solvent evaporation with the presence of soluble PVC influencing the casting solution viscosity. The experimental results fit the 1D model. In dilute casting system, the effective concentration of Ni particles in the lower part of the film was significantly enhanced and a dense, closed packed conductive network was formed. This special distribution of Ni particles was found to play a key role in the corresponding properties. Compared to the uniform film, the film which was fabricated from the casting solution containing 0.03 g/mL PVC, exhibited much better electrical conductivity and EMI shielding performance. Furthermore, the detailed study shows that the obtained thin film exhibited excellent EMI SE values per unit film thickness of 200 dB/mm. Meanwhile, the resultant films possessed thermal conductivity of 0.32$0.59 W/(mÁK) depended on whether a Ni continuous network formation throughout the whole film in the temperature range of 30$608C. Our study results pave thus the way for scalable fabrication of substrate-free systems that have advantages in multifunctional complex devices.

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Improved microwave absorption in lightweight resin-based carbon foam by decorating with magnetic and dielectric nanoparticles

Cited by 57 publications

References 39 publications

Combined effect of graphene oxide and MWCNTs on microwave absorbing performance of epoxy composites

Combined effect of graphene oxide and MWCNTs on microwave absorbing performance of epoxy composites

High‐Performance Microwave Absorption of MOF‐Derived Core‐Shell Co@N‐doped Carbon Anchored on Reduced Graphene Oxide

Facile preparation of asymmetric Ni/PVC film with controlled structure: Application as a high‐performance EMI shielding material

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