Journal of Physical Chemistry C
·
2020
·
IF 4.189
Zilong Zhang,Yaoyi He,Yangyang Lv,Lei Zhang,Xiqiao Chen,Zhuang Wu,Yanhong Zou
In this paper, two-dimensional Ti3C2Tx-MXenes with abundant defects and functional groups as well as appropriate conductivity were successfully synthesized by acid treatment at room temperature. The relationship between the surface structure and its electromagnetic wave absorption ability was systematically studied by changing etching time and heat treatment. Benefiting from the conduction loss and strong polarization relaxation around the abundant interface areas in the two-dimensional layered structure, the Ti3C2Tx Mxene composite possesses excellent electromagnetic absorption performance. Remarkably, optimized Ti3C2Tx exhibits extremely strong absorption with a minimum reflection coefficient of −65 dB, and the qualified absorbing bandwidth is up to 5 GHz. Furthermore, the ultrathin matching thickness of the Ti3C2Tx Mxene composite is 1.4 mm. The prominent absorbing performance outperforms most recently reported two-dimensional carbon materials for microwave absorption.
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 MAGNETISM AND MAGNETIC MATERIALS
·
2024
·
IF 2.5
Liang Yan,Yujing Zhang,Yilin Zhang,Rui Liu,Chuyang Liu,Fan Wu,Xuefei Miao,Er Liu,Xiaoling Peng,Jing Li,Shan Tao,Feng Xu
LaFeO 3 perovskite has possessed great potential in the field of microwave absorption considering its outstanding dielectric and magnetic properties. In this work, Bi-doped LaFeO 3 powders (BLFO) were prepared by a simple solid state reaction method. The results have demonstrated that the crystalline of LaFeO 3 and the lattice oxygen are increased with the additionally introduced Bi. As a result, the samples could exhibit the strongest microwave absorption with the minimum reflection loss (RL min ) of −39.48 dB and the effective absorption band (EAB) of 3.63 GHz (10.28–13.91 GHz) at a filling ratio of 60 wt%. The excellent microwave absorption properties are ascribed to the enhanced conductive loss, polarization relaxation and the co-existed magnetic loss. Moreover, the optimum sample exhibits the radar cross-section values below −10 dBm 2 across a wide angular range of −90° to 90° with a thickness of 2.5 mm. Therefore, this work opens up a feasible and effective way for modulating the electromagnetic properties of perovskite materials as potential microwave absorbents.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2016
·
IF 3.897
Xiangnan Chen,Jingjing Chen,Fanbin Meng,Liming Shan,Man Jiang,Xiaoling Xu,Jun Lu,Yong Wang,Zuowan Zhou
Hierarchical graphene oxide/polypyrrole composites were fabricated by initiating an in situ intercalation polymerization of pyrrole into the interlayers of graphite oxide . It was interesting that a chemical hybridizing group of HN–CO could be verified inside the graphene oxide layers during the exfoliation of graphite oxide, resulting in a new kind of graphene oxide based composites with highly crumpled structures. This intercalation compounding technique made the composite display much stronger polarization, leading to notable enhancement in electromagnetic loss with broadband responses. As an example of the 2.96 mm thickness sample, the rock-bottom on the reflection loss curve was low to −58.1 dB at 12.4 GHz and the bandwidth below −10.0 dB could be as wide as 6.2 GHz, which was remarkable superior to those of the pure graphite oxide as well as other hybrids of graphene oxide that had ever been reported. The improvement in absorbing capacity arose from the unsymmetrical groups generated from the chemical hybridization, which could lead to multi-scaled polarization relaxations. In addition, the three-dimensional intercalated network would lead to synergistically benefit of impedance matching and interfacial relaxation loss. These results provided a new strategy to prepare graphene-like composites for functional design such as high-efficient microwave absorbent.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Jie Huang,Liuying Wang,Bin Wang,Gu Liu,Chaoqun Ge,Long Wang,Weichao Wang,Kejun Xu,Mengzhou Chen,Wenhao Wang,Lingjie Hu,Haiqing Chen
Carbon nanotube (CNT)-based composites hold immense promise in the realm of electromagnetic (EM) wave absorption. Surface functionalization of CNTs plays a pivotal role in augmenting their surface binding energy, thereby bolstering their affinity for composites. However, the incorporation of functional groups may disrupt the electronic configuration of sp 2 plus delocalized π-bonds and impede electronic transport within the CNT framework. Herein, carbon dots (CDs) were introduced onto the surface of oxidized CNTs (O-CNTs) using a one-step hydrothermal method to enhance their bonding capability and microwave absorption performance. Analysis showed that the characteristic functional groups on the surfaces of the CDs formed amide bonds between the CNTs, bridging them with π-conjugated structures and repairing the blocked electron transport pathway triggered by carboxyl groups. The bridging accelerated the electron flow between adjacent CNTs and enhanced the electron jumping and migration in the CDs-CNTs system. Additionally, a comprehensive investigation of the heterogeneous charge distribution within the CDs bridges and their tunable band gap demonstrated their significant influence on polarization relaxation and conduction loss. In short, the study presents a novel functionalization theory for CNTs that exhibit remarkable microwave-absorption performance in X-band.
研究领域:
材料科学
·
电磁学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Nano Research
·
2020
·Vol. 13
·期 3
·621-629
·
IF 8.183
Pan Jialiang,Guo Honggui,Wang Min,Yang Hui,Hu Haowen,Liu Peng,Zhu Hongwei
Although Fe 3 O 4 particles have exhibited excellent microwave absorbing capacity and widely used in practical application due to the synergistic effect of magnetic loss and dielectric loss, their applications are still limited for the required high mass fraction in absorbers. To overcome this problem, the development of Fe 3 O 4 materials with low dimensional structures is necessary. In this study, the shape anisotropic Fe 3 O 4 nanotubes (NTs) with low mass ratios were applied to realize efficient microwave absorption. The NTs with different aspect ratios were prepared through facile electrospinning followed by two-step thermal treatments and mechanical shearing. The cross-linked nanotubular structure enabled the absorbers to have much higher electrical conductivity, multiple scattering, polarization relaxation and better anti-reflection surface, while the shape anisotropic NTs maintained significant multiple resonances with stronger coercivity. These all were beneficial to microwave absorption with enhanced dielectric loss, magnetic loss and sterling impedance matching. Results showed that the absorber with 33.3 wt.% of short Fe 3 O 4 NTs had minimum reflection loss of -58.36 dB at 17.32 GHz with a thickness of 1.27 mm, and had the maximum effective absorbing bandwidth (EAB) of 5.27 GHz when the thickness was 1.53 mm. The absorber with 14.3 wt.% of long Fe 3 O 4 NTs presented the widest EAB in certain radar band with attenuated 80.75% X band and 85% Ku band energy bellow -10 dB at the thickness of 2.65 and 1.53 mm, respectively. This study provided an approach for the development of shape anisotropic magnetic absorbing materials, and broadened their practical applications as magnetic absorbers.
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
·
2022
·
IF 9.965
Shijie Zhang,Yaxing Pei,Zhiwei Zhao,Chunlong Guan,Guanglei Wu
In consideration of the growing electromagnetic wave (EMW) pollution and interference, it is of crucial and imperative significance to develop high-efficiency EMW absorption materials. Herein, hierarchical hybrid network of MoS 2 @poly (3, 4-ethylenedioxythiophene) (PEDOT)/reduced graphene oxide (rGO) were successfully constructed and fabricated through the combination of oxidative polymerization and microwave-irradiated thermal reduction. The original defects in graphene oxide (GO) could be in situ repaired by introducing carbon source, and the rational regulation of polarization relaxation and conductivity of composites could be achieved. Profiting from the good impedance matching, ameliorated conductivity and enhanced dipole polarization as well as interfacial polarization by introducing GO/defect-recovered rGO and conductive PEDOT, both the MoS 2 @PEDOT/GO and MoS 2 @PEDOT/rGO composites exhibited outstanding EMW absorption performances. In details, the minimum reflection loss ( RL min ) and effective absorption bandwidth (EAB) of MoS 2 @PEDOT/GO can reach −48.65 dB at 4.5 mm, and 6.48 GHz (11.52–18 GHz) at 2.2 mm, respectively. And the EAB of MoS 2 @PEDOT/rGO can reach 7.04 GHz (10.8–17.84 GHz) with an optimized RL min of −32.41 dB at 2.1 mm under 20 wt% filler loading. Therefore, these composites can be regarded as competitive candidates for lightweight and high-efficient EMW absorbers.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2023
·Vol. 11
·期 43
·23498-23510
·
IF 11.9
Baojun Wang,Hao Wu,Wenxuan Hou,Zhifeng Fang,Heqin Liu,Fangzhi Huang,Shikuo Li,Hui Zhang
The rational integration of dielectric components is a promising approach to optimize the Maxwell–Wagner–Sillars effect (MWSE) for developing lightweight and highly efficient electromagnetic wave (EMW) absorbers. However, the controllable modulation of the dielectric polarization relaxation response remains a great challenge, and impedes the further improvement of the absorption properties. Herein, an inside-out Ostwald ripening and phase-evolution strategy is proposed for the preparation of uniform-sized hollow N-doped carbon microspheres with embedded Ni/Ni2P heterojunctions (Ni/Ni2P/CNs). The resulting Ni/Ni2P/CNs microspheres well-integrated the Ni/Ni2P heterojunctions with a hollow carbon skeleton to optimize the impedance matching and the MWSE, thus reinforcing the dielectric polarization relaxation response. Consequently, the fabricated Ni/Ni2P/CNs exhibited superior EMW-absorption performances with a minimum reflection loss of −72.2 dB at a thin matched thickness of 1.7 mm and the absorption bandwidth reached 5.8 GHz. Such remarkable performances exceed most of the previously reported absorbers with a hollow structure. The experimental results and simulation analysis demonstrated that the Ni/Ni2P/CNs microspheres possessed large interior voids, well-defined heterojunctions, and enlarged electron-redistribution regions, which are crucial contributions to optimize the MWSE and strengthen dielectric polarization. This study presents a novel avenue for the controllable design of MWSE-strengthened absorbers and provides a feasible method to reinforce dielectric polarization with balanced conduction loss and polarization loss.
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 & TECHNOLOGY
·
2023
·
IF 10.9
Kexin Jin,Xueai Li,Huimin Tang,Yuning Shi,Chunsheng Wang,Wanchun Guo,Kesong Tian,Haiyan Wang
Carbon hollow microspheres as microwave absorption materials (MAMs) are of great significance in the research focuses owing to their lightweight, good impedance matching, and modifiable dielectric properties. However, it is still a huge challenge to distinguish the contribution of dielectric attenuation between carbon intrinsic feature and hollow structure due to the lack of appropriate model materials. Then, the inadequate analysis of effective dielectric attenuation resulted in the construction of carbon hollow microspheres semiempirical and often lacked precise modification of microstructure. Herein, a series of carbon hollow microspheres with controllable graphitization and thickness of shell derived from phenolic resin coated on polystyrene microspheres that fully decomposed were synthesized, which is free of the impact of template residue. The carbon fragments ground from hollow microspheres exhibit the same broadband response as hollow microspheres, with effective bandwidth (RL ≤ –10 dB) of 7.6 GHz, while their electromagnetic wave loss mechanisms are distinct. The high dielectric loss of carbon fragments with the same intrinsic characteristics as carbon hollow microspheres is mainly caused by dipole polarization relaxation and enhancement of electrical conductivity ascribed to overlapping between carbon sheets. For the hollow structure, in addition to dipole polarization relaxation attributed to carbon intrinsic feature, the effective dielectric loss is also comprised of the interfacial polarization in advantage due to the effective heterogeneous interface between air and carbon shell. This work provides a simplified model to clarify the effect of carbon intrinsic feature and microstructure on the dielectric loss of carbon hollow microspheres.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2023
·
IF 5.9
Xingjian Dai,Quan Zhou,Lichao Dong,Chenzhi Zhang,Xinfang Zhang,Tuo Ping,Ruoting Lan,Pingan Yang,Yi Hou,Zhihao Bao,Shuang Yi,Jinsong Rao,Yuxin Zhang
The specific nanostructure of the absorber is a key factor in improving the electromagnetic absorption performance. Herein, NiFe layered double hydroxide composited with carbonyl iron powder (LDH/CIP) was fabricated by a one-step hydrothermal synthesis process for the first time. By varying the morphology of the CIP template (spherical or flaky), the nanostructure of in situ grown LDH could be modulated, to optimize the electromagnetic wave absorption performance of LDH. The resultant NiFe/CIP synergistic composite has proved its excellent electromagnetic (EM) wave absorption performance with the minimum reflection loss (RLmin) of −96.5 dB and an effective absorption bandwidth (EAB) up to 7.6 GHz at the thickness of 8 mm. At a smaller thickness of 3 mm, the EAB value remains 7.2 GHz with the RLmin of −16.4 dB. Such an outstanding absorption capacity is primarily attributed to the magnetic loss of NiFe LDH, which is more significantly enhanced using CIP as the substrate. Moreover, the formation of nano-flower-like LDHs, which possess rich heterogeneous structural interfaces and specific surface area to induce the polarization relaxation of the absorber. Therefore, the established NiFe/CIP composite brings insights into the design of high-performance EM wave absorbers.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
CARBON
·
2021
·
IF 9.594
Jun Liao,Mingquan Ye,Aijun Han,Jianming Guo,Qingzhong Liu,Gaoqiang Yu
Electromagnetic (EM) wave absorber with the characteristics of thin thickness, strong absorption capacity and broad absorption bandwidth is desirable to address the EM radiation. In this work, the flower-like Cu 9 S 5 /RGO (CSR) composites were synthesized via a solvothermal method. Various kinds of characterizations were utilized to certify the successful preparation and properties of CSR composites. To explore the EM wave absorption performance of the CSR composites, we measured the EM parameters and calculated the reflection loss (RL) values of all the samples. Owing to the comprehensive effect of well impedance matching and large attenuation constant , the CSR-2 sample exhibited the minimum RL value of −51.9 dB at the thickness of 2.8 mm, and the widest effective absorption bandwidth (EAB) is 3.92 GHz in 1.5 mm. Furthermore, the absorption mechanisms were revealed, the impressive EM wave absorption performance of the CSR-2 is inseparable from the conductive loss and polarization relaxation, as well as the slight magnetic loss. We consider that the CSR composite can be a promising candidate for efficient and superior EM wave absorption absorber.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2020
·
IF 7.489
Qiong Shang,Huixia Feng,Zeyu Feng,Nali Chen,Lin Tan,Jianhui Qiu,Hongjing Wu
Although various materials have been studied for the purpose of microwave absorption (MA), natural sepiolite (SEP) has never been reported as MA absorber. Herein, the series of sepiolite@polyaniline composites (SEP@PANI-x) with “skeleton/skin” structure were fabricated through a facile in-situ polymerization technique and firstly developed as MA materials. The electrical conductivity and dielectric properties can be well controlled via modulating the PANI content in the composites. With a lower mass ratio of 30 wt%, it is worth noting that the optimized SEP@PANI-50 could simultaneously display the optimal minimum reflection loss ( RL min ) of −50.23 dB and effective absorption bandwidth (EAB, RL < -10 dB) of 5.01 GHz with thicknesses of 2.5 and 1.8 mm, respectively. Moreover, when changing absorber thickness (1.5–5.0 mm), the RL min values lower than −20 dB (99% absorption) are all achieved and the EAB ranges the entire Ku, X, and C bands. Such excellent MA performance comes from rich conductive network and polarization relaxation, which ultimately balance the impedance matching and attenuation ability. In view of its facile synthesis route, low-cost, lightweight and excellent MA performance, SEP@PANI-50 would be a very promising MA candidate in many practical applications. More importantly, we also think that our findings will expand the application of SEP-based composites in the electromagnetic field.
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
RSC Advances
·
2019
·Vol. 9
·期 53
·30685-30692
·
IF 3.049
Sifan Zeng,Wanlin Feng,Shuyuan Peng,Zhen Teng,Chen Chen,Haibin Zhang,Shuming Peng
Multi-functional carbon fiber (CF) based composites have great potential as new-type microwave absorption materials (MAMs). However, it was still a huge challenge to integrate antioxidation and MA properties into CF based composites. Herein, the SiOC ceramics coating modified carbon fibers (SiOC/CFs) were prepared by a polymer precursor pyrolysis method. The X-ray photoelectron spectroscopy (XPS) revealed that the SiOC coating was composed of SiOC, SiO2, and amorphous carbon phases. The SiOC ceramics as dual-functional coating not only heightened the oxidation temperature from 415 °C to 890 °C, but also highly improved the microwave absorbing ability from −12.60 dB to −47.50 dB. The enhanced MA performance could be attributed to multiple reflections in the cross-linked structure, various polarization relaxation processes, and the favorable impedance matching effect. The SiOC ceramics coating as a semiconductor could suppress the skin effect originating from the cross-linked CF network, thus leading to a favorable impedance matching behavior.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）