Polymers
·
2022
·Vol. 14
·期 21
·4501
·
IF 4.967
Yanfang Zhao,Aichun Long,Pengfei Zhao,Lusheng Liao,Rui Wang,Gaorong Li,Bingbing Wang,Xiaoxue Liao,Rentong Yu,Jianhe Liao
Constructing hierarchical structures is indispensable to tuning the electromagnetic properties of carbon-based materials. Here, carbon microtubes with nanometer wall thickness and micrometer diameter were fabricated by a feasible approach with economical and sustainable kapok fiber. The carbonized kapok fiber (CKF) exhibits microscale pores from the inherent porous templates as well as pyrolysis-induced nanopores inside the wall, affording the hierarchical carbon microtube with excellent microwave absorbing performance over broad frequency. Particularly, CKF-650 exhibits an optimized reflection loss (RL) of −62.46 dB (10.32 GHz, 2.2 mm), while CKF-600 demonstrates an effective absorption bandwidth (RL < −10 dB) of 6.80 GHz (11.20–18.00 GHz, 2.8 mm). Moreover, more than 90% of the incident electromagnetic wave ranging from 2.88 GHz to 18.00 GHz can be dissipated by simply controlling the carbonization temperature of KF and/or the thickness of the carbon-microtube-based absorber. These encouraging findings provide a facile alternative route to fabricate microwave absorbers with broadband attenuation capacity by utilizing sustainable biomass.Keywords:biomass-derived carbon microtube;kapok fiber;electromagnetic loss;microwave attenuation
研究领域:
材料科学
·
电磁学
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产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2024
·
IF 5.7
Rupan Xu,Jie Zhou,Weiquan Huang,Gaoyuan Yu,Liqun Guo,Xiaogu Huang,Gaofeng Shao
Contourable design and morphological synthesis represent promising strategies for modulating the electromagnetic wave (EMW) response of nano–micro absorbers. Herein, hollow bridged polysilsesquioxane derived silicon oxycarbonitride (SiOCN) ceramic bowls were synthesized via a template-free and thermolysis method. The concave surface structure and internal cavities of SiOCN improve impedance matching and promote multiple reflections/scattering, contributing to increased microwave attenuation. Additionally, the presence of hetero-nanodomains between the free carbon phase and the amorphous SiOCN matrix generates numerous sites for dipolar and interfacial polarization, further boosting the microwave attenuation capabilities. The as-prepared SiOCN bowls exhibit a minimal reflection loss (RLmin) of −52.93 dB at 10.44 GHz (X band) with a relatively low thickness of 2.3 mm. The efficient absorption bandwidth spans 3.88 GHz with a thickness of merely 1.6 mm. Furthermore, the ability to achieve multi-band EMW absorption is facilitated by varying the absorber thickness. Radar cross-sectional (RCS) simulations indicated that the RCS reduction achieved by the perfect electric conductor shielded with hollow SiOCN bowls exceeds 15 dB m2 across frequencies ranging from the S to Ku bands. Therefore, this morphologically innovative design lays the groundwork for further exploration of polymer-derived ceramics as advanced EMW absorbers.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
高影响因子
CARBON
·
2024
·
IF 10.5
Haotian Jiang,Yanxiang Wang,Chengjuan Wang,Yanqiu Feng,Deli Yang,Yue Sun,Jinghe Guo,Bohan Ding,Shichao Dai,Dongming Liu,Chengguo Wang
Carbon aerogels have revolutionized the design of advanced electromagnetic wave absorbers by offering low density, multi-functionality, and versatility. However, traditional carbon aerogels face limitation due to their high electrical conductivity and reliance on single loss mechanism, which hinders their widespread applications. To overcome these challenges, a series of multilayered hierarchical CoNi/bamboo-like carbon nanotubes (BCNTs)/carbon nanofiber (CNFs) aerogels are prepared using directional freeze-drying, hydrothermal methods, and catalytic chemical vapor deposition. The effects of layer spacing and thermal growth on the microwave absorption properties of the hybrids are investigated by varying the content of aramid nanofibers and growth temperature. The synergistic effect of dielectric and magnetic loss optimizes the electromagnetic parameters and impedance matching of the samples, which obtains an optimal minimum reflection loss of −80.30 dB at only 2.07 mm. Furthermore, the composite aerogel demonstrates an ultra-wide effective absorption bandwidth of 6.60 GHz at 2.28 mm. The practical application capabilities of the samples are evaluated through theoretical analysis. Besides, the as-prepared aerogels exhibit excellent thermal insulation properties and the ability to adsorb light oils. This study presents an attractive strategy for fabricating CoNi/BCNTs-modified carbon aerogel absorbers, which hold great promise for applications in electromagnetic protection and thermal management devices.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2018
·Vol. 30
·期 2
·1626-1636
·
IF 2.324
Li Yuexuan,Duan Yugang
Silicon coupling reagent is regarded as a common additive on surface treatment of polymer due to its high bonding strength and low cost. In this paper, a series of γ-(2, 3-epoxypropoxy) propyltrimethoxysilane (KH560)-based reduced graphene oxide (RGO)@Fe 3 O 4 (KH560/RGO@Fe 3 O 4 ) composites with different ratio of Fe 3 O 4 nanoparticles (NPs) are synthesized by a facile hydrothermal method. It is confirmed that the silicon reagent KH560, as a hopeful candidate for increasing the RGO lattice defects, is favorable to improve the electromagnetic wave absorption. Meanwhile, the microwave attenuation mechanism of KH560/RGO@Fe 3 O 4 composite suggests that the dielectric loss mainly causes by multiple Debye dipolar relaxation and its magnetic loss comes from the eddy-current effect of Fe 3 O 4 NPs over the high frequency range. In consequence, the KH560/RGO@Fe 3 O 4 composite endows the excellent absorption performance, the reflection loss (RL) value is optimized to − 25 dB at 14.1 GHz with a thickness of 3 mm and the maximum frequency bandwidth for RL < − 10 dB is 4.1 GHz with a thickness of 4 mm.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
高影响因子
CARBON
·
2023
·
IF 10.9
Yujie Ren,Yinghan Zhang,Qi Zheng,Lianjun Wang,Wan Jiang
Porous Carbon-based composites with large specific surface area are promising as lightweight electromagnetic wave (EMW) absorbers due to their inherently rich interfaces that facilitate microwave attenuation. However, the exertion of the intrinsic advantage of large surface area was underexplored. Herein, we described a facile strategy using MOF-derived large surface area porous carbon to construct dielectric-magnetic composites for high-efficiency EMW absorbers. In particular, a series of Fe@C composites were fabricated by pyrolysis of MOF-5 to form porous carbon matrix (S BET ∼ 1800 m 2 /g), followed by ferrocene deposition and reduction. By altering Fe species amount, surface area and electromagnetic parameters of the composites were tuned. It is found Fe@C-0.6 composites with sufficiently high S BET ∼915.8 m 2 /g exhibited outstanding microwave absorption performance with the minimum reflection loss (RL min ) of −64.6 dB (1.98 mm thickness and 15 wt% loading) and the effective absorption bandwidth (EAB) up to 6.27 GHz (2.2 mm thickness). Besides, Fe@C-1 (S BET ∼820.1 m 2 /g) also achieved desirable loss capability, with EAB covering the whole Ku band . This work demonstrates the potential of high surface area to achieve optimal EMW attenuation, and may provide a facile alternative to develop more high-performance carbon composites for EMW absorption application.
研究领域:
材料科学
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电磁学
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2025
·
IF 4.7
Ya-Ru Hou,Yi-Lin Zhan,Zhe-Kun Xu,Xiao-Gang Chen,Zhong-Xia Wang,Hui-Peng Lv
Dielectric switch materials are widely used in network communication, data storage, and industry control, among which molecule-based hybrid perovskites have aroused extensive interest due to simple fabrication, lightweight, mechanical flexibility, and phase transition characteristics. However, current research on molecular materials mainly focuses on low-frequency ranges (1 kHz to 1 MHz), with limited exploration of high-frequency switching, which represents a development trend of electronics. Herein, we have synthesized three molecular perovskites, NH(CH3)3CdCl3, (CH3)4NCdCl3, and [(CH3)3NCH2Cl]CdCl3 (TMCM-CdCl3), and studied their phase transition and dielectric properties in ultrawide range from 1 kHz to 18 GHz. They undergo phase transitions at 341, 374, 402, and 400 K, respectively. Notably, TMCM-CdCl3 exhibited distinct dielectric anomalies in the whole studied frequency range, especially high-frequency dielectric switching in 12–18 GHz. NH(CH3)3CdCl3 and (CH3)4NCdCl3 only possess dielectric switching or no anomalies in low frequency bands. Dielectric loss of TMCM-CdCl3 exhibits step-like elevation across phase transition, which endows it with “on/off” switchable microwave attenuation capability (reflection loss of −42.4 dB and effective absorption bandwidth of 5.7 GHz in the on state) at a thickness of 1.6 mm. This work highlights the high-frequency dielectric switching of molecular hybrid perovskites and provides insights into functionality explorations of molecule-based materials.
研究领域:
材料科学
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凝聚态物理
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功能材料
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电子学
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介电材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Qi Li,Huiqing Liao,Donghua Wang,Shang Yang,Yi Zeng,Fazheng Qiu,Lijie Jiang
The breach of dielectric-magnetic properties severely impairs the impedance matching and microwave attenuation. Graphene, which possesses superior dielectric and conductive characteristics, has been recognized as a potential electromagnetic (EM) functional material. However, the lack of magnetic response undermines the dielectric-magnetic balance of graphene, eventuating the impedance mismatch and weak microwave attenuation. Modulating the EM parameters to stimulate microwave propagation and attenuation is an ingenious strategy for premium microwave attenuation materials. Herein, the controlled titration chemical reduction and annealing were engaged to facilitate the in-situ growth of Ni nanoparticles on reduced graphene oxide (rGO). The self-assembly Ni/rGO nanocomposites harbor the rich heterointerfaces and reticulum-like microporous to bridge the dielectric-magnetic gap and manipulate well-matched impedance matching. Correspondingly, the maximum reflection loss of −37.5 dB was performed at 2.0 mm, and the effective absorption bandwidth of 5 GHz was achieved within 1.6 mm. Theoretical simulation of radar cross-sectional (RCS) has been developed, and the prominent RCS reduction value of 25.68 dB·m 2 was obtained with the detection theta of 0°. This work is an exciting step forward in the potential for tailoring superior microwave absorption materials through the manipulation of the dielectric-magnetic balances.
研究领域:
材料科学
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纳米技术
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电磁吸收
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化学合成
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2024
·Vol. 14
·期 14
·9716-9724
·
IF 3.9
Wentao Yu,Jiahui Lin,Zhaozhang Zhao,Jiyong Fang,Ziqing Wang,Jintao Huang,Yonggang Min
This study successfully utilized a straightforward approach, choosing liquid–liquid phase separation to build a porous structure and synthesize composite absorbers based on polyimide-based porous carbon and cobalt nanoparticles (designated as PPC/Co-700 and PPC/Co-800). A fine porous structure was achieved as a result of the excellent heat resistance of polyimide resulting in an excellent electromagnetic wave absorption ability of PPC/Co composites. The results obtained clearly indicated that PPC/Co-700 and PPC/Co-800 exhibit a porous structure with coral-like pores, enhancing both impedance matching properties and microwave attenuation abilities. This improvement in impedance matching conditions and dissipation capability is attributed to the synergistic effect of dielectric loss induced by carbon and magnetic loss induced by Co nanoparticles. PPC/Co-700 showed the strongest absorption performance with a minimum reflection loss of −59.85 dB (30 wt% loading, thickness of 3.42 mm) and an effective absorption bandwidth (EABW, RL ≤ −10 dB) of 6.24 GHz (30 wt% loading, thickness of 2.78 mm). Therefore, this work provides a facile strategy for the development of a promising absorbing material with outstanding electromagnetic wave absorption performance.
研究领域:
材料科学
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电磁工程
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanoscale
·
2024
·
IF 5.8
Yuke Zheng,Yunliang Dai,Yiwen Fu,Xiaojuan Zhang
Structural construction and heteroatom doping are deemed effective strategies for designing a high-performance microwave absorbing composite to eliminate electromagnetic hazards. Herein, a series of core–shell structural carbon@N-doped carbon (C@NC) nanospheres were successfully fabricated without employing additional modifying agents and sophisticated operation. After incorporating them into a polyvinylidene fluoride (PVDF) matrix, the C@NC/PVDF composites possess tunable wave attenuation capacity obtained by regulating the coating layer thickness and filler loading. Benefitting from the design strategy of the core–shell structure and N-doped C, the C@NC-2/PVDF composites displayed the broadest effective absorption bandwidth of 6.29 GHz (11.71–18 GHz) under a filler content of only 10 wt% at 2.01 mm. Additionally, the minimum reflection loss value of C@NC-3/PVDF composites achieves −62.87 dB within the same mass ratio at a thickness of 2.35 mm. The excellent wave dissipation ability is attributed to the combination of optimized impedance matching and synergistically enhanced multiple loss mechanisms including conduction loss, interfacial polarization as well as dipolar polarization. This work offers a ponderable paradigm for the deeper exploitation of high-efficiency carbon absorbers.
研究领域:
材料科学
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电磁材料
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微波吸收
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2025
·
IF 9.5
Han Liu,Zhenyu Xu,Zhiyue He,Housheng Mao,Jiayang Lin,Naixin Zhai,Zhenzhi Cheng,Fei Gao,Guangsheng Luo,Weiping Zhou
Ultrathin and broadband microwave absorption materials are urgently needed for mitigating the detrimental effects of electromagnetic pollution for 5G applications and military stealth. In this work, high entropy heterostructured composites composed of oxides/alloys with abundant heterogeneous interfaces are engineered by introducing in-situ metal conductive phase through high-temperature reduction on solid-phase-sintered high-entropy spinel ferrites (CoNiCuX)Fe2O4. By further tailoring the elemental composition (X=Mn, Zn, Mg, Cr, MnMg, and MnCr), the dielectric, magnetic and conduction properties of the high-entropy heterostructured composites are modulated, resulting in enhanced microwave attenuation ability and optimized impedance matching characteristics. As a result, the (Co0.2Ni0.2Cu0.2Mn0.2Mg0.2)Fe2O4 derived high-entropy oxides (HEOs)/ferroalloy dual-phase composite simultaneously exhibits a minimal reflection loss of -48.77 dB accompanied by a maximum effective absorption bandwidth (EAB) of 6.08 GHz (11.92-18 GHz) at a thickness of only 1.5 mm. Furthermore, an ultra-broadband EAB of 11.5 GHz is realized by constructing macroscale gradient multilayer metamaterials with a thickness of 4.0 mm. This study demonstrates that reasonable composition and heterointerfaces engineering can facilitate synergistic effect of polarization loss, conduction loss and magnetic loss, which enables the heterostructured composites to exhibit superior impedance matching and enhanced microwave loss capability, thus achieving superior microwave absorption performance at thin matching thickness.
研究领域:
材料科学
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微波工程
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电磁兼容性
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纳米技术
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复合材料
·
固体物理学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Qingfu Ban,Yan Li,Yusheng Qin,Yaochen Zheng,Xiubo Xie,Zhen Yu,Jie Kong
The rational regulation of the magnetic-dielectric composition and microstructures of the absorber is considered an important approach to optimize both the impedance matching and the electromagnetic microwave attenuation ability. Along these lines, a novel architecture-controlled large-caliber carbon nanotube/mesoporous carbon/Fe 3 C nanoparticle-based hybrid nanocomposites (CNT/C/Fe 3 C), which were derived from the CNT/polyimide (PI) assemblies anchoring ferric oxide hydrate nanoprecipitates, are presented in this work. The proposed configurations were prepared by applying a cooperative co-assembly strategy and high-temperature pyrolysis procedure for the development of an ultra-lightweight electromagnetic microwave absorber. The employed hierarchically tubular heterogeneous architecture is composed of a highly graphited CNT supporting skeleton, polyimide assemblies-converted carbon interlayer with mesopores , and uniformly distributed magnetic Fe 3 C nanoparticles. This unique hierarchical structure can not only induce multiple reflection and scattering effects of the incident electromagnetic microwave but also trigger dipole/interfacial polarization, ferromagnetic resonance and eddy current loss that are beneficial for the synergistic dielectric and magnetic loss. Moreover, the large-caliber CNT and mesoporous carbon interlayer can endow the as-prepared absorber with lightweight characteristics. Hence, the proposed CNT/C-EDA/Fe 3 C-900 hybrid nanocomposite exhibits a minimum reflection loss (RL) of −48.4 dB at a matching thickness of 3.2 mm, and the effective absorption bandwidth (RL ≤ -10 dB) almost covers the whole X-band only with a 5 wt% filler loading. Undoubtedly, these encouraging outcomes will promote the development of hierarchical engineering techniques of novel magnetic-dielectric nanocomposite absorbers.
研究领域:
材料科学
·
纳米技术
·
电磁工程
·
复合材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）