Journal of Materiomics
·
2021
·
IF 6.425
Jialiang Pan,Rujing Zhang,Jun Ling,Min Wang,Zechen Li,Zhen Zhen,Limin He,Hongwei Zhu
To substantially prevent electromagnetic threatens, microwave absorbing materials (MAMs) are required to eliminate surplus electromagnetic waves. As a typical MAM, Fe 3 O 4 particles with complex permittivity and permeability have been widely applied due to the coexistence of magnetic loss and dielectric loss. However, the necessary high mass fraction significantly limited its applications, thus Fe 3 O 4 nanostructures have been extensively investigated to overcome this problem. In this work, uniform Fe 3 O 4 nanobelts were prepared by electrospinning and two-step thermal treatment. By controlling the composition and viscosity of the electrospinning precursor solution, Fe 3 O 4 nanobelts with tunable lateral sizes (200 nm–1 μm) were obtained. The samples with low content (only 16.7 wt%) Fe 3 O 4 exhibited wide maximum effective absorbing bandwidths (EAB) over 3 GHz, and Fe 3 O 4 nanobelts with smaller lateral sizes showed a maximum EAB of 4.93 GHz. Meanwhile, Fe 3 O 4 nanobelts with smaller lateral sizes presented superior reflection loss properties, the lowest reflection loss reached −53.93 dB at 10.10 GHz, while the maximum EAB was up to 2.98 GHz. The excellent microwave reflection loss of Fe 3 O 4 nanobelts was contributed to the enhanced synergistic effect of magnetic loss, dielectric loss, and impedance matching, originated from the hierarchically cross-linked networks and shape anisotropies. This study could broaden the practical applications of magnetic absorbers, and provided an approach for the development of shape anisotropic magnetic materials.
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 ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Danqiang Huang,Jianfeng Dai,Qing Wang,Hui Liu,Zengpeng Li
A multi-component, special structure of electromagnetic wave absorber produces significant electromagnetic wave absorption performance because of excellent impedance matching. In this work, CoFe 2 O 4 @CNTs composites are prepared. CoFe 2 O 4 exhibits a hollow and open-hole shape with a rough surface, and this structure facilitates more electromagnetic wave absorption. The incorporation of multiwalled carbon nanotubes (MWCNTs) leads to dipole polarization and when wrapped around CoFe 2 O 4 particles, increases the interface loss. The influence of the filler-loading ratio on the microwave absorption performance of wax-based absorbers is thoroughly investigated. The highest electromagnetic wave absorption performance is obtained at 25% filling with a minimum reflection loss (RL min ) of − 36.52 dB at a thickness of 1.9 mm and effective absorption bandwidth (EAB) is 3 GHz. In this study, a method is proposed for creating high-performance electromagnetic wave 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
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2018
·
IF 3.141
Mingjie Guo,Xiang Jiang,Heqing Fu
First, [(1-x)MnO2-xMWCNTs] (MMCs) nanocomposites and modified [(1-x)MnO2-xMWCNTs] (mMMCs) nanocomposites were synthesized. Then, novel modified [(1-x)MnO2-xMWCNTs]/waterborne polyurethane (mMMCs/WPU) composites with good microwave absorption properties were prepared by in situ polymerization. The chemical functionalized MMCs and mMMCs nanocomposites were characterized by FTIR and XRD. The structure and properties of the mMMCs/WPU composites were investigated by SEM, TGA, tensile testing, and vector network analyses. The experimental results showed that when the mMMCs nanocomposites were introduced into WPU the thermal stability and tensile strength of mMMCs/WPU composites were improved. When the content of MWCNTs was 20 wt % (where x = 0.2), m[(1-x)MnO2-xMWCNTs]/WPU composites exhibited good microwave absorption properties. The minimum RL value can reach −28.7 dB at 6.4 GHz with a thickness of 2.5 mm. The mMMCs/WPU composites have good thermal stability and tensile strength, which could be used as promising materials for microwave absorption.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2022
·
IF 10.319
Yameng Jiao,Qiang Song,Xuemin Yin,Liyuan Han,Wei Li,Hejun Li
Due to the limited electromagnetic wave (EMW) loss capacity and agglomeration, carbon black (CB) gradually fails to meet the increasingly harsh demanding conditions. Herein, defect-rich bamboo-like carbon nanotubes (CNTs) were grown on CB by the process of chemical vapor deposition . CNTs prepared in situ on CB can assist it to build a developed multilevel conductive network and introduce plentiful CB/CNTs nano-interfaces. What's more, the defects that accompany the growth of CNTs endow CNTs with a moderate conductivity and good impedance matching, thereby causing an effective microwave absorption (MA). Meanwhile, the high-density defects on CNTs can induce dipole polarization to further strengthen the EMW loss ability. The influence of CNTs with different growth time on MA performance has been explored. Profiting from the structural merits, the synthesized CB-CNT with CNTs growth time of 40 min exhibits the optimal absorbing property, which has the minimum reflection loss of -53.6 dB and maximum effective absorption bandwidth of 4.1 GHz with the thickness of 2.7 mm, covering almost the entire X band. The introduction of defect-rich CNTs significantly enhances the EMW loss ability of CB, which provides a rational strategy for the design of high-efficient microwave absorption materials.
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
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2018
·Vol. 29
·期 9
·7539-7550
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IF 2.324
Sui Mingxu,Sun Xiaodong,Lou Hongfei,Li Xiaopeng,Lv Xuliang,Li Ling,Gu Guangxin
Hollow Fe 3 O 4 particles with variable crystal sizes were synthesized by one-step solvothermal method for lightweight and efficient microwave absorber applications. The reactant concentration, reaction temperature and reaction time are three key factors for morphology control of the products and can further influence the microwave absorption properties. The diameters of as-prepared hollow magnetite particles ranged from 200 to 1000 nm, while the shell thickness differed from 35 to 280 nm. It is found that the microwave absorption properties are improved along with the increasing of the hollow structure size which depend on the reaction conditions. The sample prepared at 200 °C for 36 h exhibited an optimal reflection loss of − 55.14 dB at 11.76 GHz with the thickness of 2.07 mm, while possessing the broadest effective bandwidth reaching 4.72 GHz (5.6–10.32 GHz) at 2.49 mm. The excellent microwave absorbing properties of such materials can be attributed to the high magnetic loss and favorable impedance matching property.
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 Chemistry C
·
2016
·Vol. 4
·期 32
·7614-7621
·
IF 5.066
Junyao Shen,Yongtao Yao,Yanju Liu,Jinsong Leng
We demonstrate a facile, template-free route for Fe nanowires (NWs) with an average diameter of 100 nm through magnetic-field-assisted hydrothermal conditions. The aspect ratio of the Fe NWs reaches 50. Fe NWs are constructed with interconnected bead-like nanospheres, which are composed of primary nanocrystals (NCs) with an average size of 8 nm. This shows that the polycrystalline Fe NWs have a body-centred cubic (bcc) structure with preferential growth on the 〈110〉 zone axis. Such hierarchical structures involve orientational growth in the presence of an external magnetic field. The molarity of the reducing agent, reaction time and temperature, are further investigated to understand the influence of these parameters on the growth process of Fe NWs. Compared with those of Fe nanoparticles (NPs), the magnetic properties of Fe NWs show both higher saturation magnetization (154.03 emu g−1) and coercivity (360.84 Oe). The peak value of reflection loss (RL) reaches up to −27.28 dB at 3.68 GHz, indicating the excellent microwave absorption performance of the Fe NWs for low gigahertz usage (2–6 GHz). This mild approach to control Fe NWs is easy to scale-up for other iron-related magnetic nanodevice applications.
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
Advanced Materials Interfaces
·
2022
·Vol. 9
·期 14
·2200333
·
IF 6.389
Xiaoyan Yuan,Huanhuan Li,Aiming Sha,Shengyan Huang,Bo Li,Shouwu Guo
Materials with 1D structure exhibit a remarkable advantage for losing electromagnetic (EM) wave energy. Herein, flexible Mo 2 C-modified SiC/C nanofibers (Mo-SiC/C NFs) are synthesized for the first time by co-electrospinning and subsequent high-temperature pyrolysis, using polycarbosilane (PCS) and molybdenum acetyl acetone (MoO 2 (acac) 2 ) as precursors. It is found that the polymer derived temperature of PCS is significantly decreased by introducing MoO 2 (acac) 2 , as well as endowing the SiC/C NFs with good flexibility, high crystallinity, and remarkable microwave absorption performance. The as-prepared fibers dispersed in paraffin with a low filler loading (15 wt%) exhibit a minimum reflection loss (RL, dB) of -62.5 dB, and a wide effective absorption bandwidth (EAB, RL<-10 dB) of 6.8 GHz at 2.75 mm. Meanwhile, the EAB of the hybrid can cover the whole X-band and most of the C-band by modulating its thickness. These high-efficient performances mainly originate from the specific 1D microstructure, abundant interfaces and defects, and synergistic effect among SiC, Mo 2 C, and C matrix. Thus, this work offers a way to explore flexible SiC/C NFs as a promising candidate with lightweight and wide EAB for EM wave absorption.
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
·
2022
·
IF 11.307
Wentong Yang,Jiawen Sun,Deyun Liu,Wenwen Fu,Yubing Dong,Yaqin Fu,Yaofeng Zhu
Reasonable combination of components and ingenious structure design are effective strategies to achieve superior microwave absorption (MA). In this work, polyaniline was grown in situ on hollow porous carbon microspheres prepared by polymerization and pyrolysis-etching processes. The synthesized hollow porous carbon@polyaniline (HPC@PANI) shows a specific hierarchical structure and possesses extraordinary MA properties . The optimal minimum reflection loss ( RL ) of HPC@PANI is as high as −64.31 dB at 13.80 GHz with a thin thickness of 1.86 mm, and the corresponding effective absorption bandwidth (EAB, RL ≤ −10 dB) is as wide as 4.85 GHz (11.90 GHz–16.75 GHz). The mechanism of such superior MA properties is associated with well impedance matching, strong loss capabilities and well-defined structural characteristics. It is expected that the design of HPC@PANI with hierarchical structures in this work could provide ideas for the structural design of efficient MA materials .
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
NANOTECHNOLOGY
·
2021
·Vol. 32
·期 38
·385602
·
IF 3.874
Ximing Zhang,Jingyu Wang,Yang Fan,Hengdong Ren,Zhenying Liu,Yanfen Wang,Yin Liu,Hongcun Bai,Lingbing Kong
In this work, we prepared NiCo alloy/C with rhombic dodecahedron structure and superior microwave absorption performance by using ZIF-67 as the raw material. The rhombic dodecahedron NiCo alloy/C was with rough particles on the surface was photographed by field emission scanning electron microscopy. By adjusting the doping amount of Ni and the temperature of pyrolysis, improved the impedance matching of NiCo alloy/C. Specifically, NiCo alloy/C exhibits a minimum reflection loss of −65.48 dB at 13.48 GHz, while the thickness is 1.63 mm. Defects introduced in the Ni doping process and the special rhombic dodecahedral structure can cause multiple loss mechanisms. Therefore, this NiCo alloy/C composite has the potential to be a potential microwave absorber material with lightweight and high microwave absorption properties.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Composites and Hybrid Materials
·
2021
·Vol. 4
·期 4
·1292-1301
·
IF 5.693
Zhang Pengxiang,Zhang Xihua,Li Bin,Xu Lingan,Dang Feng,Li Bao-Wen
Improving the interfacial impedance matching and attenuation ability of a microwave absorber is an important strategy to obtain excellent microwave absorbing performance. Here, we prepared an ultralight, hierarchical porous single-atom Co–N–C microwave absorber, in which evenly distributed single-atom Co is anchored in a porous N-doped carbon framework by N–Co bond via a facile bio-inspired method. These doped single atoms provide abundant highly active atomic absorption sites on the carbon skeleton, and considerable defects including pyridinic-N, pyrrolic-N, oxidized N, and so forth are introduced into the carbon framework owing to single Co atom doping. These doped single Co atoms and introduced defects act together as strong dipolar/interfacial polarization units, which lead to better impedance matching and a significant increase in attenuation capability of the absorber. The metal Co exists in form of a single atom, benefiting light weight of the absorber. Therefore, an extremely strong reflection loss (RL) value of − 60.9 dB is achieved at a lower filler content of 10 wt% with the absorber thickness of 2.5 mm, and the effective frequency bandwidth covered from 10.4 to 15.1 GHz with a thickness of 2.0 mm at a low filler content of 10 wt%. This research offers a novel route for designing a microwave absorber to improve microwave absorption performance and is expected to a wider range of absorbing materials with different structures. Graphical abstract
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 21
·26189-26201
·
IF 2.478
Zhang Xian-Hui,Liu Jun-Jun,Zha Liang-Liang,Chen Ji-Wei,Chen Bao,Wu Jian-Hua,Yu Hong-Liang
MnZn ferrites and their magnetic, electrical, and optical properties make them highly suitable in a number of applications. These ferrites are used in electronic applications, magnetic fluids, and household appliances such as washing machines, refrigerators, and microwave ovens. This paper focuses on a hydrothermal method used to prepare a bayberry spherical manganese–zinc ferrite (Mn 0.5 Zn 0.5 Fe 2 O 4 ), its surface was coated with dopamine (Mn 0.5 Zn 0.5 Fe 2 O 4 @PDA) and then carbonized to obtain the core–shell structure C-Mn 0.5 Zn 0.5 Fe 2 O 4 @PDA. Preliminary results show that carbon-coated manganese–zinc ferrite with saturation magnetic properties and coercivity increased from 99 emu and 66.01 Oe to 138 emu and 104.85 Oe, respectively. In addition, the carbonized Mn 0.5 Zn 0.5 Fe 2 O 4 @PDA (C-Mn 0.5 Zn 0.5 Fe 2 O 4 @PDA) exhibited favorable microwave absorbing performance with minimum reflection loss (RL min ) of − 17.56 dB and also revealed that the broadest effective absorption bandwidth (RL min ≤ − 10 dB) 5.36 GHz (11.70–17.06 GHz) can be achieved at 2.0 mm.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Jiahang Qiu,Zhen Xin,Mu Zhang,Xudong Sun
Due to the multiple scattering of microwaves and the existence of electron aggregation polarization at heterogeneous interfaces, the design of hollow or anisotropic microstructures has always been one of the research focuses of microwave absorption materials (MAMs). In this work, an effective strategy has been proposed reasonably to manufacture yolk-shell pompon-like Fe@void@CeO 2 @Ni nanospheres via hydrogen reduction and multiple solvothermal procedures. The results show that the metallic iron core with a diameter of 300 nm and the outer CeO 2 layer with a thickness of 70 nm compound to form a yolk-shell structure, and the metallic nickel nanosheets with a length of about 100 nm are evenly embedded in the CeO 2 layer to form a pompon-like structure. These unique microstructures provide heterogeneous interfacial polarization, three-dimensional conductive networks, and multiple electromagnetic scattering which bring excellent dielectric loss to the composites. Combined with the inherent strong magnetic loss of magnetic metals, as-prepared composites exhibit excellent microwave absorption properties. The minimal RL value reaches −48.9 dB and the efficient absorption bandwidth reaches 14 GHz with the thickness ranges from 2.5 to 7 mm. Hence, this unique microstructural design scheme has great prospects in the field of MAMs.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）