Ultralight polymer-derived ceramic aerogels with wide bandwidth and effective electromagnetic absorption properties

Zhao, Wanyu; Shao, Gang; Jiang, Mingjie; Zhao, Biao; Wang, Hailong; Chen, Deliang; Xu, Hongliang; Li, Xinjian; Zhang, Rui; An, Linan

doi:10.1016/j.jeurceramsoc.2017.04.068

Cited by 67 publications

(36 citation statements)

References 48 publications

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“…c is the light velocity in vacuum, t is the thickness of the absorber, f is the microwave frequency. derived from different precursors pyrolyzed with the presence or absence of catalyst, 1,6,9,10,13,14,16,17,20,[27][28][29][30][31][32][33] the metal-loaded carbon material as a kind of wave absorbing filler incorporated into the pyrolyzed matrix with low conductivity also presents excellent wave absorbing properties, such as Co and Fe 3 O 4 . The EMW absorbing performance of materials is depended on the complex permittivity and permeability ( r = � − j �� ), and for nonmagnetic SiC material, � = 1 and �� = 0.…”

Section: Electromagnetic Wave Absorbingmentioning

confidence: 99%

“…Therefore, the higher conductivity and less interfacial polarization result in the EMW absorbing property of S-1000 inferior to S-1500. F I G U R E 9 Electromagnetic wave absorbing properties of PDCs with and without catalysts pyrolyzed at different pyrolysis temperatures 1,6,9,10,13,14,16,17,20,[27][28][29][30][31][32][33] [Color figure can be viewed at wileyonlinelibrary.com]…”

Section: Electromagnetic Wave Absorbingmentioning

confidence: 99%

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Enhanced electromagnetic wave absorbing properties of Si‐O‐C ceramics with in‐situ formed 1D nanostructures

Ding

Wang

Xiao

et al. 2019

Int J Applied Ceramic Tech

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The Si‐O‐C ceramics were prepared by polymer‐derived ceramic method using polysiloxane/FeCl3 as precursor with the FeCl3 content of 1.0 wt%. The microstructure, dielectric properties, and electromagnetic wave (EMW) absorbing properties in X band of the Si‐O‐C ceramic were investigated. It was found that the pyrolysis temperature has a great influence on the amount of in‐situ formed CNTs and the transformation from CNTs to 1D SiC nanostructures. With the temperature rising from 1000 to 1500°C, the SiC formed with various morphologies including SiC microspheres, needle‐like SiC, and SiC nanowires which were transformed from CNTs. The EMW absorbing properties were dramatically improved when the pyrolysis temperature raised to 1500°C; the minimum reflection loss (RL) was −58.37 dB of sample with a thickness of 2.95 mm at 10.11 GHz, and the absorbing band (RL ≤−20 dB) of sample at a thickness of 3.0 mm covers 3.8 GHz (8.2‐12.0 GHz), which means more than 99% of the EMW were absorbed. The enhancement of EMW absorbing properties of bulk Si‐O‐C ceramics was attributed to the interfacial polarization induced by in‐situ heterogeneous nanostructures with complex interfaces.

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Section: Electromagnetic Wave Absorbingmentioning

confidence: 99%

Section: Electromagnetic Wave Absorbingmentioning

confidence: 99%

Enhanced electromagnetic wave absorbing properties of Si‐O‐C ceramics with in‐situ formed 1D nanostructures

Ding

Wang

Xiao

et al. 2019

Int J Applied Ceramic Tech

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“…PDC aerogels have been synthesized and characterized for gas sensing [6], anodes for Li-ion batteries [7], water purification [8], and electromagnetic adsorbers [9]. For example, SiCO aerogels were found to show good sensing response towards N 2 at 300 °C and H 2 at 500 °C [6].…”

Section: Introductionmentioning

confidence: 99%

Towards Porous Silicon Oxycarbide Materials: Effects of Solvents on Microstructural Features of Poly(methylhydrosiloxane)/Divynilbenzene Aerogels

et al. 2018

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We investigate the impact of solvents on the microstructure of poly(methylhydrosiloxane)/divinylbenzene (PMHS/DVB) aerogels. The gels are obtained in highly diluted conditions via hydrosilylation reaction of PMHS bearing Si-H groups and cross-linking it with C=C groups of DVB. Polymer aerogels are obtained after solvent exchange with liquid CO2 and subsequent supercritical drying. Samples are characterized using microscopy and porosimetry. Common pore-formation concepts do not provide a solid rationale for the observed data. We postulate that solubility and swelling of the cross-linked polymer in various solvents are major factors governing pore formation of these PMHS/DVB polymer aerogels.

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“…As shown in Additional file 1: Figure S5, the real and imaginary parts of complex permeability are nearly equal to 1 and 0, respectively, which is ascribed to the non-magnetism of HPSCs. Figure 5c shows a comparison of RL min value versus thickness of similar Si-based ceramics materials in recent studies [12][13][14][29][30][31][32][33][34][35]. Additional file 1: Table S1 lists the detailed MA data of all related references.…”

Section: Resultsmentioning

confidence: 99%

Carbon Nanofibers Propped Hierarchical Porous SiOC Ceramics Toward Efficient Microwave Absorption

et al. 2020

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The hierarchical porous SiOC ceramics (HPSCs) have been prepared by the pyrolysis of precursors (the mixture of dimethicone and KH-570) and polyacrylonitrile nanofibers (porous template). The HPSCs possess hierarchical porous structure with a BET surface area of 51.4 m 2 /g and have a good anti-oxidation property (only 5.1 wt.% weight loss). Owing to the porous structure, the HPSCs deliver an optimal reflection loss value of − 47.9 dB at 12.24 GHz and an effective absorption bandwidth of 4.56 GHz with a thickness of 2.3 mm. The amorphous SiOC, SiO x , and free carbon components within SiOC make contributions to enhancing dipolar polarization. Besides, the abundant interfaces between SiOC and carbon nanofibers (CNFs) are favorable for improving interfacial polarization. The conductive loss arisen from cross-linked CNFs can also boost the microwave absorption performance.

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Ultralight polymer-derived ceramic aerogels with wide bandwidth and effective electromagnetic absorption properties

Cited by 67 publications

References 48 publications

Enhanced electromagnetic wave absorbing properties of Si‐O‐C ceramics with in‐situ formed 1D nanostructures

Enhanced electromagnetic wave absorbing properties of Si‐O‐C ceramics with in‐situ formed 1D nanostructures

Towards Porous Silicon Oxycarbide Materials: Effects of Solvents on Microstructural Features of Poly(methylhydrosiloxane)/Divynilbenzene Aerogels

Carbon Nanofibers Propped Hierarchical Porous SiOC Ceramics Toward Efficient Microwave Absorption

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