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Engineering hierarchical heterostructure material based on metal-organic frameworks and cotton fiber for high-efficient microwave absorber

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Nano Research 2022年第8期15卷 6841-6850页

作者： Yan Guo Hu Liu Dedong Wang Zeinhom M.El-Bahy Jalal T.Althakafy Hala M.Abo-Dief Zhanhu Guo Ben Bin Xu Chuntai Liu Changyu Shen Key Laboratory of Materials Processing and Mold(Zhengzhou University) Ministry of EducationNational Engineering Research Center for Advanced Polymer Processing TechnologyZhengzhou UniversityZhengzhou 450002China Department of Chemistry Faculty of ScienceAl-Azhar UniversityNasr City 11884CairoEgypt Department of Chemistry Faculty of Applied ScienceUmm Al-Qura UniversityMecca 21955Saudi Arabia Department of Chemistry College of ScienceTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia Integrated Composites Laboratory(ICL) Department of Chemical&Biomolecular EngineeringUniversity of TennesseeKnoxvilleTN 37996USA Department of Mechanical and Construction Engineering Faculty of Engineering and EnvironmentNorthumbria UniversityNewcastle upon TyneNE18STUK

Rational construction of hierarchical multi-component materials with abundant heterostructure is evolving as a promising strategy to achieve excellent metal-organic frameworks(MOFs)based electromagnetic wave(EMW)absorbers.Herein,hierarchical heterostructure WS_(2)/CoS_(2)@carbonized cotton fiber(CCF)was fabricated using the ZIF-67 MOFs nanosheets anchored cotton fiber(ZIF-67@CF)as a precursor through the tungsten etching,sulfurization,and carbonization process.Apart from the synergetic effect of dielectric-magnetic dual-loss mechanism,the hierarchical heterostructure and multicomponent of WS_(2)/CoS_(2)@CCF also display improved impedance matching.Furthermore,numerous W-S-Co bands and heterojunction interfaces of heterogeneous WS_(2)/CoS_(2)are beneficial to promoting additional interfacial/dipole polarization loss and conductive loss,thereby enhancing the EMW attenuation performance.Based on the percolation theory,a good balance between impedance matching and EMW absorption capacity was achieved for the WS_(2)/CoS_(2)@CCF/paraffin composite with 20 wt.%filler loading,exhibiting strong EMW absorption capability with a minimum reflection loss(RLmin)value of−51.26 dB at 17.36 GHz with 2 mm thickness and a maximum effective absorption bandwidth(EABmax)as wide as 6.72 GHz.Our research will provide new guidance for designing high-efficient MOFs derived EMW absorbers.

关键词： hierarchical heterostructure sulfurization metal-organic framework microwave absorber

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Double-layer microwave absorber of nanocrystalline strontium ferrite and iron microfibers

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Chinese Physics B 2012年第2期21卷 541-547页

作者：韦春余沈湘黔宋福展 School of Materials Science and Engineering Jiangsu UniversityZhenjiang 212013China

microwave absorption properties of the nanocrystalline strontium ferrite （SrFe12O19） and iron （α-Fe） microfibers for single-layer and double-layer structures are investigated in a frequency range of 2 GHz 18 GHz. For the singlelayer absorbers, the nanocrystalline SrFe12O19 microfibers show some microwave absorptions at 6 GHz 18 GHz, with a minimum reflection loss （RL） value of -11.9 dB at 14.1 GHz for a specimen thickness of 3.0 mm, while for the nanocrystalline α-Fe microfibers, their absorptions largely take place at 15 GHz-18 GHz with the RL value exceeding -10 dB, with a minimum .RL value of about -24 dB at 17.5 GHz for a specimen thickness of 0.7 mm. For the doublelayer absorber with an absorbing layer of α-Fe microfibers with a thickness of 0.7 mm and matching layer of SrFe12O19 microfibers with a thickness of 1.3 ram, the minimum RL value is about -63 dB at 16.4 GHz and the absorption band width is about 6.7 GHz ranging from 11.3 GHz to 18 GHz with the RL value exceeding -10 dB which covers the whole Ku-band （12.4 GHz 18 GHz） and 27% of X-band （8.2 GHz 12.4 GHz）.

关键词： nanocrystalline microfibers microwave absorber double-layer structure

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Effect of Adding microwave absorber on Structures and Properties of Hypercoal-Based Activated Carbons

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Journal of Wuhan University of Technology(Materials Science) 2020年第3期35卷 488-494页

作者：谢立军樊丽华 HOU Caixia LIU Junke SUN Zhang College of Chemical Engineering North China University of Science and TechnologyTangshan 063210China Hebei Province Key Laboratory of Photocatalytic and Electrocatalytic Materials for Environment Tangshan 063210China

Using lignite-based hypercoal as raw material, KOH as activator and CuO as microwave absorber, we prepared hypercoal-based activated carbons by microwave-assisted activation. The pore structure and the electrochemical performance of the activated carbons were tested, and the effects of adding CuO in the activation reaction process were also investigated. The activated carbons prepared were characterized by nitrogen adsorption-desorption, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The specific surface area and mesoporous ratio of the hypercoal-based activated carbon are 1257 m2/g and 55.4%, respectively. When the activated carbons are used as the electrode materials, the specific capacitance reaches 309 F/g in 3 M KOH electrolyte. In comparison with those prepared without CuO absorber, the specific capacitance increases by 11.6%. It was proved that the addition of microwave absorber in microwave-assisted activation was a low-cost method for rapidly preparing activated carbon, and it could effectively promote the development of the pore structure and improve its electrochemical performance.

关键词： hypercoal activated carbon microwave absorber pore structure electrochemical performance

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Two-dimensional materials： Emerging toolkit for construction of ultrathin high-efficiency microwave shield and absorber

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Frontiers of physics 2018年第4期13卷 53-91页

作者： Mingjun Hu Naibo Zhang Guangcun Shan Jiefeng Gao Jinzhang Liu Robert K. Y. Li School of Materials Science and Engineering Beihang University Beijing 100191 China Beijing Research and Development Center the 54th Research Institute Electronics Technology Group Corporation Beijing 100070 China School of Instrumentation Science and Opto-electronics Engineering Beihang University Beijing 100191 China School of Chemistry and Chemical Engineering Yangzhou University Yangzhou 225002 China Department of Materials Science and Engineering City University of Hong Kong Hong Kong China

Two-dimensional （2D） materials generally have unusual confined electro-strong interaction in a plane and can physical and chemical properties owing to the exhibit obvious anisotropy and a significant quantum-confinement effect, thus showing great promise in many fields. Some 2D materials, such as graphene and MXenes, have recently exhibited extraordinary electromagnetic-wave shielding and absorbing performance, which is attributed to their special electrical behavior, large specific surface area, and low mass density. Compared with traditional microwave attenuating materials, 2D materials have several obvious inherent advantages. First, similar to other nanomaterials, 2D materials have a very large specific surface area and can provide numerous interfaces for the enhanced interfacial polarization as well as the reflection and scattering of electromagnetic waves. Second, 2D materials have a particular 2D morphology with ultrasmall thickness, which is not only beneficial for the penetration and dissipation of electromagnetic waves through the 2D nanosheets, giving rise to multiple reflections and the dissipation of electromagnetic energy, but is also conducive to the design and fabrication of various well-defined structures, such as layer-by-layer assemblies, core-shell particles, and porous foam, for broadband attenuation of electromagnetic waves. Third, owing to their good processability, 2D materials can be integrated into various multifunctional composites for multimode attenuation of electromagnetic energy. In addition to behaving as microwave reflectors and absorbers, 2D materials can act as impedance regulators and provide structural support for good impedance matching and setup of the optimal structure. Numerous studies indicate that 2D materials are among the most promising microwave attenuation materials. In view of the rapid development and enormous advancement of 2D materials in shielding and absorbing electromagnetic wave, there is a strong need to summarize the recent research results in this field fo

关键词： electromagnetic interference shielding microwave absorber graphene MXenes polymernanocomposites

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Multicomponent induced localized coupling in Penrose tiling for electromagnetic wave absorption and multiband compatibility

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Journal of Materials Science & Technology 2022年第35期130卷 86-92页

作者： Xinran Ma Yuping Duan Lingxi Huang Ben Ma Hao Lei Key Laboratory of Solidification Control and Digital Preparation Technology(Liaoning Province) School of Materials Science and EngineeringDalian University of TechnologyDalian 116085China

In the electronic information and intelligent era, microwave absorption materials have been focused on the issue of electromagnetic(EM) pollution, but high-performance absorbers with thin thickness are highly desirable. The positive action between structural design and component selection can be regarded as a function to optimize the microwave loss capacity, which contributes to understanding the response mechanisms from the micro and macro. Therefore, we designed the absorber with quasiperiodic structures of Penrose tiling that has finely engineered the location of maximum absorption peak, the spherical carbonyl iron in thin rhombus, and flakey carbonyl iron in fat rhombus, the effective absorption bandwidth(Reflection Loss ≤ –10 d B) was realized from 6.46 GHz to 15.78 GHz in the 2 mm thickness. The unique arrangement of Penrose tiling can respond alternatingly to EM waves at large scales, and multicomponent coupling is distinctly in the neighboring unit cells. In addition, spraying aluminum pigment as the upper layer, the infrared emissivity is less than 0.35 to meet the complex application environment.This work opens up novel ideas on quasiperiodic structure combined multicomponent and injects infinite vitality to provide prospects for broadband responsive and high-efciency EM absorbers.

关键词： microwave absorber Penrose tiling Carbonyl iron Localized coupling

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Enhanced microwave Absorption for High Filler Content Composite Molded from Polymer Coated Flaky Carbonyl Irons Modified by Silane Coupling Agents

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Journal of Wuhan University of Technology(Materials Science) 2023年第1期38卷 42-51页

作者：崔正明 MA Guoqing WANG Mengqi LUO Chuangyu CHEN Zhihong MA Huiru LI Qifan 李维 State Key Laboratory of Advanced Technology for Materials Synthesis and Processing School of Materials Science and EngineeringWuhan University of TechnologyWuhan 430070China School of Science Wuhan University of TechnologyWuhan 430070China Department of Chemistry School of ChemistryChemical Engineering and Life ScienceWuhan University of TechnologyWuhan 430070China School of Physics and Electronic Science Hubei UniversityWuhan 430062China

A microwave absorbing sheet with a high complex permeability and a relatively low complex permittivity is obtained by molding of the densely coated flaky carbonyl iron particles(FCIPs)by styrenebutadiene-styrene block copolymer(SBS)in the assistance of coupling agent modification.Direct molding of the core-shell FCIPs without adding extra binder results in a large permeability due to the high filling ratio(55vol%)of absorbents.Importantly,the permittivity is well suppressed by the dense insulate polymer shell on the FCIPs,avoiding the severe impedance mismatch problem of the high filler content microwave absorbing materials.Investigations show that modifying the surface of FCIPs by proper amount of silane coupling agent is critical for the coating quality of the SBS shell,which is verified by resistivity and corrosion current density measurements,and can be interpreted by improved interfacial compatibility between the modified FCIPs and SBS.The obtained microwave absorbing sheet shows a minimum reflection loss of-38.74 dB at 1.57 GHz and has an effective absorption bandwidth from 1.1 to 2.3 GHz at a relatively small thickness of 2 mm.

关键词： microwave absorber coating quality magnetic permeability permittivity low frequency

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Tunable natural resonances via synergistic effects of two phases in Fe_(x)(Co_(y)Ni_(1-y))_(100-x)for multi-band microwave absorption

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Journal of Materiomics 2023年第1期9卷 90-98页

作者： Renchao Hu Desheng Pan Xinwei Xu Bin Xiao Hong Wang Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen518055China Shenzhen Engineering Research Center for Novel Electronic Information Materials and Devices&Guangdong Provincial Key Laboratory of Functional Oxide Materials and Devices Southern University of Science and TechnologyShenzhen518055China

Multi-band microwave absorption is becoming ubiquitous owing to the increasingly complex electromagnetic environment driven by the diversity of electronic devices.However,research on efficient electromagnetic absorbers applicable in both centimeter-wave and millimeter-wave bands to address the electromagnetic interference in 5G networks is highly challenging.In this study,Fe_(x)(Co_(y)Ni_(1-y))_(100-x)particles with two phases(face-centered cubic(FCC)and hexagonal close-packed(HCP))were synthesized and were found to exhibit excellent electromagnetic wave absorption.HCP phase with high magnetocrystalline anisotropy was introduced into FCC phase Fe_(x)(Co_(y)Ni_(1-y))_(100-x),resulting in natural resonances in multi-band frequency.Prominent microwave absorption properties in ultra-wide bandwidth ranging from 6.9 to 39.5 GHz were obtained.The maximum reflection loss(RL)of the Fe_(23)(Co_(0.5)Ni_(0.5))77 composite film reached-50 dB.Such a remarkable absorption performance is attributed to the synergetic effects of the multiple natural resonances generated by the coexistence of HCP and FCC phases in Fe23(Co0.5Ni0.5)77.Overall,this work is promising for the future design of high-performance microwave absorbing materials in a wide bandwidth.

关键词： Submicron particles microwave absorber Anisotropy Permeability Microstructures

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Fabrication and electromagnetic wave absorption properties of amorphous Ni-P nanotubes

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Chinese Physics B 2011年第6期20卷 139-144页

作者：陆海鹏韩满贵蔡黎邓龙江 State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of China

Amorphous Ni-P nanotubes are fabricated through electroless chemical deposition inside an anodic aluminum oxide template. The hysteresis loops of Ni-P nanotube arrays are each found to exhibit an unusual isotropic behaviour, which is believed to be due to the competition results between the shape anisotropy and the magnetostatic interaction among nanotubes. The dynamic dependence of permittivity on the frequency spectrum is fitted to the Lorentzian-type dispersion law. The permeability dispersion behaviours have been fitted based on the Kittel equation. Electromagnetic wave absorption properties of Ni-P nanotubes/paraffin composites with different values of thickness （t） are clearly shown by a three-dimensional graph. Furthermore, the bandwidths of composites with different ＂t＂ values can be well presented by a two-dimensional contour graph, which is a novel presentation form. The results show that the composites each have a good microwave absorption performance with t larger than 5.5 mm and with the frequency around 8 gigahertz.

关键词： magnetic permeability permittivity microwave absorber magnetic nanotubes

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Tunable wideband absorber based on resistively loaded lossy high-impedance surface

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Chinese Physics B 2015年第10期24卷 181-185页

作者：党可征时家明汪家春林志丹王启超 State Key Laboratory of Pulsed Power Laser Electric Engineering Institute

A lossy high-impedance surface comprised of two layers of resistive frequency selective surfaces is employed to design a tunable electromagnetic absorber. The tunability is realized through changing the composite unit cell by moving the top layer mechanically. To explain the absorbing mechanism, an equivalent circuit model with an interacting coefficient is proposed. Then, simulations and measurements are carried out and agree well with each other. Results show that the complex structure with a thickness less than λ0/4 is able to achieve a wideband absorption in a frequency range from5.90 GHz to 19.73 GHz. Moreover, it is tunable in the operation frequency band.

关键词： frequency selective surface high-impedance surface microwave absorber tunable

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Annealing effects on the microwave permittivity and permeability properties of Fe_(79)Si_(16)B_5 microwires and their microwave absorption performances

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Chinese Physics B 2009年第3期18卷 1261-1265页

作者：韩满贵欧雨梁迪飞邓龙江 State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of China

This paper reports that amorphous magnetic microwires （Fe79Si16Bs） have been fabricated by a melt-extraction technique and have been annealed at 600℃ and 750℃ respectively. Differential scanning calorimeter measurements show that nanocrystalline magnetic phase （α-Fe） has been formed in the amorphous matrix when it was annealed at 600℃. Hard magnetic phase （Fe2B） was formed in the microwires annealed at 750℃, which increases the magnetic coercivity. microwave permittivity and permeability are found to be dependent on the microstruetures. The permittivity fitting results show that multi Lorentzian dispersion processes exist. For microwires annealed at 750℃, their resonance peaks due to the domain wall movements and natural resonance are found higher than those of microwires annealed at 600℃. The microwave absorption performance of microwires annealed at 600℃ is found better than microwires annealed at 750℃.

关键词： amorphous magnetic microwires magnetic permeability permittivity microwave absorber

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