JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2019
·
IF 6.361
Xingliang Chen,Zirui Jia,Ailing Feng,Bingbing Wang,Xiaohua Tong,Chuanhui Zhang,Guanglei Wu
In this work, a novel Fe 3 O 4 @C@MnO 2 hybrid was successfully synthesized via facile method. The morphology, structure, chemical composition , magnetic behavior and EM wave absorbing performance of the hybrid were systematically investigated. Results indicate that the hybrid possesses uniform hierarchical and mesoporous structure. The magnetic saturation(Ms) value of the hybrid is 19.8 emu g −1 , which is beneficial to improve magnetic loss. According to its reflection loss curve, the hybrid performs superior EM wave absorption capacity, with a minimum reflection loss value and effective absorbing bandwidth of −35 dB and 5 GHz when the specimen thickness is 2.7 mm. The excellent performance of this hybrid can mainly be attributed to its ideal matching of magnetic loss and dielectric loss, large specific surface area, mesoporous structure and interfacial polarizations. Such new material has the potential to be a superior electromagnetic wave absorber, or applied as a functional filler to modify resin matrix.
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
Journal of Materials Chemistry C
·
2018
·Vol. 6
·期 15
·4201-4207
·
IF 5.976
Heng Guo,Jian Yang,Bingxue Pu,Haiyuan Chen,Yulan Li,Zhiming Wang,Xiaobin Niu
Given the remarkable progress in physical and structural performances of organic–inorganic lead halide perovskites as a superstar in the photovoltaic field, the study of some of their intrinsic properties is still missing. Herein, we report the microwave absorption performance of MAPbX3 (MA = CH3NH3+, X = I−, Br− or Cl−) perovskite crystals in terms of complex permittivity and permeability. We find that the MAPbI3, MAPbBr3 and MAPbCl3 perovskites possess excellent microwave absorbability, and the optimum reflection losses reach −55.23, −54.70 and −46.44 dB at 16.77, 15.46 and 13.54 GHz with a matching thickness of 1.62, 1.76 and 1.95 mm, respectively. Thereafter, we explore the absorption mechanism and find that the microwave absorption properties can be ascribed to the combination of dielectric loss and magnetic loss, but mainly dielectric loss. In addition, the stability of microwave absorbability is also investigated and it is proved to depend significantly on the decomposition of corresponding perovskites. These results highlight the importance of the discovery of microwave absorbability of organic–inorganic lead halide perovskites. More importantly, our study provides perovskite absorbers as a new variable to be considered in the quest for future microwave devices.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
CARBON
·
2022
·
IF 11.307
Fangyu Gan,Qingrong Yao,Jianqiu Deng,Feng Wang,Lichun Cheng,Yucheng Chen,Huaiying Zhou,Yan Zhong,Huabin Yang,Yazhou Zhao
Layered double hydroxides (LDH) are employed as a promising template to prepare magnetic polymetallic alloys with hierarchical or hollow structure, being regarded as the promising candidates for the lightweight and high-performance electromagnetic wave (EMW) absorption materials . However, the application of LDH-derived magnetic alloys in EMW absorption is still limited by the single loss mechanism and poor impedance matching properties. Coupling with dielectric materials is a viable strategy to solve the issue. Herein, flower-like hierarchical FeNi@C microspheres are fabricated by pyrolysis of FeNi-LDH precursors, which display excellent EMW absorption performance . Good impedance matching and strong absorption capability of the FeNi@C microspheres can be realized by regulating the phase composition and microstructure under different pyrolysis temperatures. When pyrolyzed at 700 °C, the FeNi@C microspheres exhibit a strong reflection loss (RL) of −30.4 dB with ultra-thin matching thickness of only 1.2 mm, achieving the widest effective bandwidth (RL < −10 dB) of 4.6 GHz at 1.4 mm. The superior EMW absorption performance of the FeNi@C-700 sample is ascribed to the synergistic effects of hierarchical structure with multiple reflection, FeNi particles with magnetic loss and carbon matrix with dielectric loss. Thus, the as-obtained FeNi@C microspheres can be a prospective lightweight EMW absorber. This work can also provide guidance for design and development of hierarchical LDH derivatives in EMW 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
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Heguang Liu,Shaoqing Wu,Caiyin You,Na Tian,Yuan Li,Nitin Chopra
Magnetic nanomaterials have been shown to be effective additives to conductive materials for enhancing electromagnetic interference shielding (EMI) shielding performance, but the comprehensive mechanism remains unknown. Herein, a 3D flexible carbon foam composite decorated with Fe 3 O 4 nanoparticles was designed and constructed. The composite exhibited good flexibility and mechanical strength (approximately 45 KPa). Due to the synergistic effect of dielectric and magnetic losses, the composite delivered a shielding effectiveness (SE) of 21 dB in the X-band and a corresponding specific SE (SSE) value of 210 dB cm 2 /g. The transmission coefficient ( T ) was discovered to be as low as 0.008, indicating that the composite can successfully shield EM, while the reflection coefficient ( R ) was found to be higher than the absorption coefficient ( A ). Moreover, the complicated permittivity, permeability, and magnetism magnetization of the composite were discussed in order to better understand the origin of the composite's shielding behavior.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Xiangfeng Shu,Sheng Wang,Wenjie Wu,Sifan He,Hengdong Ren,Yenan Song,Zhenjie Zhao
Polyaniline (PANI)-based networks combined with Fe 3 O 4 hollow spheres and carbon balls (FCP) for improved electromagnetic wave (EMW) absorption were investigated using an easy-to-industrialize solvothermal and physical method. Hollow structure Fe 3 O 4 spheres with a lower density than that of the common solid sphere were prepared. As a thin and light magnetic material, Fe 3 O 4 hollow spheres generate magnetic loss, carbon balls and PANI networks generate dielectric loss. The magnetic and conductive parts play appropriate roles in achieving complementarity in the EMW absorption. The relatively high specific surface area introduced by PANI networks promotes interfacial polarization and further supports dielectric loss. In conclusion, the above reasons provide multiple attenuation mechanisms. Samples FCP1 (−65.109 dB, at 12.800 GHz, 1.966 mm, from 5.6 to 18.0 GHz) and FCP2 (−61.033 dB, at 8.480 GHz, 3.328 mm, from 4.3 to 18.0 GHz) demonstrated a wide bandwidth, a small thickness, a minimum reflection loss (R L ), and a low loading ratio (25%) in paraffin-based composites. Specifically, their loading ration of 25% is much lower than the loading ratio of conventional materials (usually 50% and above). In addition, the bandwidth is excessively wide, above 12 GHz, possessing good absorption performance in continuous intervals with different thicknesses. Such excellent characteristics have rarely been reported in literature.
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 COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Feng Dong,Bo Dai,Hao Zhang,Yuxia Shi,Rui Zhao,Xuan Ding,Hankun Wang,Tingxi Li,Mingliang Ma,Yong Ma
The design of heterostructures with reasonable chemical composition and spatial structure is one of the effective strategies to achieve high performances electromagnetic wave (EMW) absorption. Herein, reduced graphene oxide (rGO) nanosheets decorated with hollow core–shell Fe 3 O 4 @PPy (FP) microspheres have been prepared by the combination of hydrothermal method, in situ polymerization method, directional freeze-drying and hydrazine vapor reduction. FP acting as traps can consume EMW trapped into their interior through the magnetic and dielectric losses. RGO nanosheets forming the conductive network are served as multi-reflected layers. Moreover, the impedance matching is optimized by the synergistic effect between FP and rGO. As expected, the synthetic Fe 3 O 4 @PPy/rGO (FPG) composite shows excellent EMW absorption performances with the minimum reflect loss (RL min ) of −61.20 dB at 1.89 mm and the effective absorption bandwidth (EAB) of 5.26 GHz at 1.71 mm. The excellent performances for the heterostructure are attributed to the synergistic effect of conductive loss, dielectric loss, magnetic loss, multiple reflection loss, and optimized impedance matching. This work provides a simple and effective strategy for the fabrication of lightweight, thin and high-performances EMW absorbing materials.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Meiqi Mu,Jing Yu,Zhiqian Yao,Suqiong Xu,Chuicai Rong,Xianke Zhang,Zuzhou Xiong,Xingquan Wang,Xiaokang Li,Jujun Yuan
CeO 2 /Co/C composites have been successfully prepared by a template method. When being applied as electromagnetic (EM) wave absorbers, CeO 2 /Co/C composites exhibit stronger EM wave absorption properties than Co/C and CeO 2 /C composites. The enhanced performance can be attributed to the unique structures of CeO 2 /Co/C composites, in which the synergistic effect of conductance loss, polarization loss together with magnetic loss play an important role for improving the EM wave absorption properties. Additionally, the CeO 2 /Co/C composites own more heterogeneous interfaces and high porosity, which promotes the continuous occurrence of interface polarization and dipole polarization, resulting in increased multiple scattering. The CeO 2 /Co/C composites show a RL min of − 55.02 dB and an EAB of 3.29 GHz at the matching thickness of 2.82 mm. This work provides an effective strategy for constructing CeO 2 /Co/C composites for microwave absorbing material with high performances.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
SYNTHETIC METALS
·
2023
·
IF 4.4
Xinbo Zhao,Mingyu Bei,Fubin Liu,Fan Bu,Xiaohui Jiang,Liangmin Yu
Porous and layered structures can enhance interfacial polarization, and hierarchical porous composites have high dielectric loss, which can improve electromagnetic wave (EMW) absorption performance, but challenges remain. In this paper, flower-like Ni/C nanocomposites with different morphologies were obtained by adjusting the amount of solvent and heat treatment after the Ar atmosphere. The results show that Ni metals lead to magnetic loss and carbon nanotubes lead to conduction loss, and electromagnetic synergy promote enhance interfacial polarization. Moreover, the large specific surface area and hierarchical porous increase the propagation path of electromagnetic waves, resulting in scattering and multiple reflection of the EMW. Therefore, a minimum reflection loss of − 42.8 dB corresponding to an absorption bandwidth of 5.7 GHz was achieved for the Ni/C nanocomposites. This work shows that the MOF-based Ni/C composites can provide a great idea for the design and manufacture of wave-absorbing materials.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2022
·
IF 5.436
Peng Miao,Zhen Yu,Weixing Chen,Rui Zhou,Weifeng Zhao,Kai-Jie Chen,Jie Kong
High-performance microwave-absorbing materials (MAMs) derived from metal–organic frameworks (MOFs) have attracted considerable attention due to their tunable chemical composition and microstructure. In this contribution, a core–shell-structured Co/MnO/C nanocomplex was prepared using a CoMn-MIL MOF by a facile hydrothermal synthesis and subsequent pyrolysis process. The optimal microwave absorption (MA) property of the as-prepared Co/MnO/C nanocomplex was achieved by the regulation of the Co2+/Mn2+ molar ratio. The minimum reflection loss (RLmin) of the Co/MnO/C-31 nanocomplex was low to −55.0 dB at 16.2 GHz with a thickness of 1.49 mm, and the effective absorption bandwidth (EAB) was high to 5.95 GHz (12.05–18 GHz) at a thickness of 1.8 mm. The mixed-metal nanocomplex with the core–shell structure exhibited outstanding MA performance, corresponding to the synergetic effect of the magnetic and dielectric loss. It provides a high efficiency strategy for rendering low reflection loss and broad EAB to high-performance MAMs.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
Advanced Composites and Hybrid Materials
·
2024
·Vol. 7
·期 6
·1-14
·
IF 23.2
Qiu Jiahang,Zhang Mu,Zhao Rongzhi,Sun Xudong,He Dianning
The quest for broadband electromagnetic wave absorption to satisfy the demands of various fields has emerged as a prominent research focus in the domain of electromagnetic wave absorption. By considering the effects of magnetic loss and polarization loss across different frequency bands, the development of composite materials incorporating magnetic metal particles and single metal atoms may facilitate an expansion of the electromagnetic wave absorption frequency range. Consequently, we synthesized FeCo@C/Ni@C composites derived from FeCo Prussian blue analogues and polydopamine through wet chemistry and pyrolysis methods. The chelation mechanism of polydopamine, combined with the physical barrier effect provided by Zn ions during synthesis, endows the FeCo@C/Ni@C composite with low-frequency magnetic loss characteristics from the FeCo alloy, high-frequency dipole polarization losses attributed to Ni atoms, and conductivity losses arising from the coupled carbon matrix. Ultimately, the composite exhibits exceptional electromagnetic wave absorption performance: at a thickness of 2.26 mm, it achieves a minimum reflection loss value of − 50.1 dB along with an effective absorption bandwidth reaching up to 6.0 GHz. In summary, this work presents a novel strategy for enhancing broadband absorption capabilities in electromagnetic wave absorbing materials.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Xiang Li,Lujun Yu,Laiming Yu,Yubing Dong,Qiang Gao,Qixin Yang,Wentong Yang,Yaofeng Zhu,Yaqin Fu
Chiral polyaniline (PANI) with superhelical structure is successfully synthesized via in situ polymerization using chiral acid as dopant and self-assembly technique. The morphology and structure were characterized by scanning electron microcopy, transmission electron microscopy, fourier transform infrared spectra, circular dichroism, X-ray diffractometer and X-ray photoelectron spectra, which demonstrate polyaniline has chirality and superhelical structure. A possible formation process of the superhelical structure was also discussed. The microwave absorption properties of superhelical chiral PANI was investigated in the frequency range of 2–18 GHz. The results indicated that the superhelical chiral PANI exhibit substantially enhanced electromagnetic losses compared to conventional PANI. The minimum reflection loss ( RL ) of the superhelical chiral PANI can reach −31.7 dB at 11.7 GHz, and the bandwidth less than −10 dB is 3.8 GHz with absorber thickness of 1.7 mm. The enhanced microwave absorbing property can be attributed to multi-loss mechanisms, good impedance matching and the cross-polarization effects resulting from the superhelical structure and chirality.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
Nanoscale
·
2016
·Vol. 8
·期 16
·8899-8909
·
IF 7.76
Jiyong Fang,Tao Liu,Zheng Chen,Yan Wang,Wei Wei,Xigui Yue,Zhenhua Jiang
A method combining liquid–liquid phase separation and the pyrolysis process has been developed to fabricate the wormhole-like porous carbon/magnetic nanoparticles composite with a pore size of about 80 nm (WPC/MNPs-80). In this work, the porous structure was designed to enhance interaction between the electromagnetic (EM) wave and the absorber, while the magnetic nanoparticles were used to bring about magnetic loss ability. The structure, morphology, porosity and magnetic properties of WPC/MNPs-80 were investigated in detail. To evaluate its EM wave attenuation performance, the EM parameters of the absorber and wax composite were measured at 2–18 GHz. WPC/MNPs-80 has an excellent EM wave absorbency with a wide absorption band at a relatively low loading and thin absorber thickness. At the absorber thickness of 1.5 and 2.0 mm, minimum RL values of −29.2 and −47.9 dB were achieved with the RL below −10 dB in 12.8–18 and 9.2–13.3 GHz, respectively. The Co and Fe nanoparticles derived from the chemical reduction of Co0.2Fe2.8O4 can enhance the graphitization process of carbon and thus improve dielectric loss ability. Polarizations in the nanocomposite absorber also play an important role in EM wave absorption. Thus, EM waves can be effectively attenuated by dielectric loss and magnetic loss through multiple reflections and absorption in the porous structure. WPC/MNPs-80 could be an excellent absorber for EM wave attenuation; and the design strategy could be extended as a general method to synthesize other high-performance absorbers.
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
危险品化学品经营许可证（带存储）