Synchronously oriented Fe microfiber &amp; flake carbonyl iron/epoxy composites with improved microwave absorption and lightweight feature

Nan, Hanyi; Qing, Yuchang; Gao, Hui; Jia, Hongyao; Luo, Fa; Zhou, Weihua

doi:10.1016/j.compscitech.2019.107882

Cited by 58 publications

(16 citation statements)

References 41 publications

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“…Recently, high-performance microwave absorption materials (MAMs) have fascinated a tremendous attention for considered absorption under thin thickness. On the other hand, microstructures could manipulate the electromagnetic loss effectively, e.g., the core-shell microstructure in favor of enhance interface polarization, [28] porous microstructure facilitate to eliminate the skin effect at interface to consume microwaves, [29] flake microstructure tend to break through the Snoek limit of ferromagnetic materials to improve magnetic loss, [30] as well as the orientation, [7] defects, [31] distribution, [32] spacing, [33] and size [34] of the microstructures have significant effects on absorption. Nevertheless, when the ferromagnetic materials are rejected in order to avoid their disadvantages, common microstructures in dielectric materials can only control the permittivity, which give rise to the absence of permeability thus impedance mismatch.…”

Section: Introductionmentioning

confidence: 99%

Chiral Asymmetric Polarizations Generated by Bioinspired Helical Carbon Fibers to Induce Broadband Microwave Absorption and Multispectral Photonic Manipulation

Huang

Duan

Shi

et al. 2022

Advanced Optical Materials

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as stealth systems, [1] electromagnetic pollu tion eradicators, [2] and various electronic and communicational devices, [3] etc. [4] Broadband absorption is key factor of MAMs, which derived from two types of materials: [5] dielectric loss materials (graphene, [6] carbon nanotubes, [7] biomass carbon materials, [8] conductive polymer, [9] ZnO, [10] MnO 2 , [11] etc.) and magnetic loss materials (ferrite, [12] carbonyl iron, [13] high entropy alloys, [14] and other ferromagnetic alloys [15] ). Previous studies have demonstrated that MAMs with both dielectric loss (permittivity) and magnetic loss (permeability) were more easily to achieve good impedance match and thus broadband absorption. [16] Common method for fabricating mentioned electromagnetic complexes was mixing dielectric and magnetic matters, the carbonyl iron/carbon nanotubes composite absorbers could exhibit double resonance of the complex permittivity and permeability, thus reach effective absorption (reflection loss (RL) ≤ −10 dB) within 9.7-18 GHz regime under 1.4 mm thickness. [17] However, such addition of ferromagnetic materials brings some disadvantages such as high density and easy oxidation. The mentioned drawback could be avoid by some complicated synthetic method such as doping ferromagnetic ions in dielectric materials, [3] or preparing metal-organic frameworks (MOFs). [18] In addition to the intrinsic parameters of materials, metastructures [19] and microstructures [20] could give MAMs new design freedoms to broad absorption bandwidth. Metastructures can give MAMs additional effect to form metamaterials, [21] which could improve the absorption bandwidth by constructing equivalent circuit models, [22] vortex current loss, [23] overlapped reflections, [24] and polarization rotation, [25] etc., a metamaterial with square unit cells made of carbon black can achieve absorption bandwidth that 2.35-18 GHz (absorptivity more than 96.8%) under thickness of 17 mm, [26] our previous works brought optical rotation of chiral metamaterials based on high entropy alloys to consume microwaves, the effective absorption bandwidth (RL ≤ −10 dB) covered 4-5.54, 6.66-8.12, and 8.84-18 GHz under 20 mm thickness. [27] Whereas the thickness of metamaterials has to close to wavelength, because the loss effects of metamaterials are generated by subwavelength resonance that based on wave theory, thus difficult to broadband Chirality, in which electromagnetic characteristic promotes asymmetric polarization, is expected to realize broadband absorption for microwave absorption materials (MAMs). Herein, inspired by the microstructure of nepenthes, a scalable approach is reported for fabricating hierarchical-chiral helical carbon fibers with broadband microwave absorption as well as multispectral chiral manipulation. The chiral potential barriers are established by applying helically distributed stress to the fiber, which induce helical electric dipoles via positive and negative charges accumulated at the potential barriers. The states of polarization loss by Debye relaxat...

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Section: Introductionmentioning

confidence: 99%

Chiral Asymmetric Polarizations Generated by Bioinspired Helical Carbon Fibers to Induce Broadband Microwave Absorption and Multispectral Photonic Manipulation

Huang

Duan

Shi

et al. 2022

Advanced Optical Materials

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“…To solve these problems, enormous efforts have been devoted to explore and develop EMI shielding materials that can prevent the EM waves from transmitting through reflection and/or absorption. [1][2][3][4] Conventional metal are verified as one of the most effective EMI shielding materials, which however suffers from the disadvantages like high density, susceptible to corrosion, inferior flexibility, complex, and uneconomic processing; moreover, the primary shielding mechanism of metal is reflection which is undesirable for application where absorption-dominated shielding is requested to avoid second reflection pollution. Conducting polymer composites (CPCs) consisting of electrically conductive fillers and polymer matrix can serve as an alternative, which can overcome abovementioned deficiency and also are multifarious, besides, the shielding mechanism can be regulated through composition and micro-macro structure design.…”

Section: Introductionmentioning

confidence: 99%

“…For instance, Yan prepared porous graphene/PS composites by compression molding and saltleaching method, the composites with 30 wt% graphene loading exhibited specific shielding effectiveness (SE) of 64.4 dB cm 3 /g. 16 Zheng's group reported porous graphene/ PEI and graphene@Fe 3 O 4 /PEI composites prepared by phase separation, when loaded with 10 wt% filler, the maximum specific SE was 44 dB cm 3 /g and 41.5 dB cm 3 /g, respectively. 17, 18 Ameli prepared a stainless steel fiber/PP foam composites by foam injection molding, which presented the SE of 48 dB and the specific SE 75 dB cm 3 /g.…”

Section: Introductionmentioning

confidence: 99%

Light-weight carbon fiber/silver-coated hollow glass spheres/epoxy composites as highly effective electromagnetic interference shielding material

Chen

Qin

et al. 2021

Journal of Reinforced Plastics and Composites

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Highly effective electromagnetic interference shielding materials with light-weight feature are urgently demanded for releasing electromagnetic pollution. In this study, the hollow glass spheres were coated with silver particles to produce electrically conductive microspheres. The Carbon fiber/silver-coated hollow glass spheres (Ag@HGMs)/epoxy composites were manufactured by composites liquid molding process. The electromagnetic interference shielding properties of the composites were investigated in the X-band (8.2–12.4 GHz) range. The Ag@HGMs play a role in filling up the vacancy of the conductive network of carbon fibers in the composites, which not only form new conductive pathways but also act as bridges to connect CFs and provide additional channels for the electron transfer within the composites thus improving the electrical conductivity. The total shielding effectiveness (SET) increases with increasing Ag@HGMs loadings and the maximum SET is high as 88.1 dB. The increased SET dominated by absorption loss SEA is attributed to the high conductivity and multilayer construction of carbon fiber veil. The maximum specific SE of the carbon fiber/Ag@HGMs/epoxy composites can achieve 128.8 dB cm3/g, simultaneously the tensile strength and modulus can reach 95.6 MPa and 2.71 GPa, which provides a facile and promising strategy for designing and developing light-weight and high performance electromagnetic interference shielding materials.

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“…Microwave attenuation of microwave absorbing materials (MAMs) is affected by dielectric properties, magnetic properties, and electromagnetic impedance matching, which are dependent on the design of composition, interfaces, shapes, and dimensions. − Zinc oxide (ZnO) with a wide band gap ( E g = 3.37 eV) can be used in the field of EMW absorption due to its dielectric loss caused by intrinsic defects and polarization relaxation. − Due to impedance mismatching, the use of nonmagnetic ZnO is restricted in practical applications. Nevertheless, ZnO combined with magnetic loss materials, such as iron, cobalt, nickel, and related alloys, can enhance the impedance matching of MAMs.…”

Section: Introductionmentioning

confidence: 99%

N-Doped Carbon Fibers with Embedded ZnFe and Fe₃C Nanoparticles for Microwave Absorption

Guo

Zou

et al. 2021

ACS Appl. Nano Mater.

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Microwave absorbing materials (MAMs) play a vital role in the field of electromagnetic wave pollution protection. Herein, multiple interfacial ZnFe/Fe 3 C@C porous nanofibers as a microwave absorber were prepared by electrospinning and subsequent thermal treatment. The elaborately designed ingredients and porous feature of the structure introduce good impedance matching. The multiple interfacial heterojunction structure and the self-doping of nitrogen atoms of the proposed carbon-based magnetic fibers promote dielectric polarization relaxation. Moreover, the attenuation capacity and impedance matching can be adjusted by the carbothermal temperature. The obtained composites exhibit excellent microwave absorption performance, which possess a minimum reflection loss of −33.57 dB at 13.92 GHz and an effective absorption bandwidth (RL < −10 dB) of 4.16 GHz. These favorable characteristics and excellent performance of ZnFe/Fe 3 C@C porous nanofibers can promote the development of an efficient, lightweight microwave absorber.

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Synchronously oriented Fe microfiber & flake carbonyl iron/epoxy composites with improved microwave absorption and lightweight feature

Cited by 58 publications

References 41 publications

Chiral Asymmetric Polarizations Generated by Bioinspired Helical Carbon Fibers to Induce Broadband Microwave Absorption and Multispectral Photonic Manipulation

Chiral Asymmetric Polarizations Generated by Bioinspired Helical Carbon Fibers to Induce Broadband Microwave Absorption and Multispectral Photonic Manipulation

Light-weight carbon fiber/silver-coated hollow glass spheres/epoxy composites as highly effective electromagnetic interference shielding material

N-Doped Carbon Fibers with Embedded ZnFe and Fe₃C Nanoparticles for Microwave Absorption

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Synchronously oriented Fe microfiber & flake carbonyl iron/epoxy composites with improved microwave absorption and lightweight feature

Cited by 58 publications

References 41 publications

Chiral Asymmetric Polarizations Generated by Bioinspired Helical Carbon Fibers to Induce Broadband Microwave Absorption and Multispectral Photonic Manipulation

Chiral Asymmetric Polarizations Generated by Bioinspired Helical Carbon Fibers to Induce Broadband Microwave Absorption and Multispectral Photonic Manipulation

Light-weight carbon fiber/silver-coated hollow glass spheres/epoxy composites as highly effective electromagnetic interference shielding material

N-Doped Carbon Fibers with Embedded ZnFe and Fe3C Nanoparticles for Microwave Absorption

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N-Doped Carbon Fibers with Embedded ZnFe and Fe₃C Nanoparticles for Microwave Absorption