CARBON
·
2016
·
IF 6.198
Chen Zhou,Sai Geng,Xiuwen Xu,Tihong Wang,Liqiang Zhang,Xiaojuan Tian,Fan Yang,Haitao Yang,Yongfeng Li
Hollow carbon nanospheres (HCNs) with tunable sizes have been successfully prepared by the calcination of hollow copolymer nanospheres. Our findings indicate that compared to the counterpart solid carbon particle , HCNs all achieve substantially enhanced microwave absorption, suggesting that hollow structure plays an important role during microwave absorption. Moreover, further investigation on the effect of different HCNs sizes upon microwave absorption has been conducted. It is found that HCNs with an outer diameter of ∼70 nm and inner diameter of ∼30 nm exhibit the champion EM absorption performance , a minimum reflection loss (RL) of −50.8 dB at 13.5 GHz with a thickness of 1.9 mm, along with the corresponding bandwidth of RL less than −10 dB (90% absorption) covering 4.8 GHz. Notably, such excellent microwave absorption performance, probably as a result of well-matched impedance together with multiple reflection induced by the distinctive hollow structure, demonstrates HCNs to be one of the most competitive carbon-based absorbers to date. More importantly, this study provides an effective strategy to tune the microwave performance via tailoring the sizes of HCNs.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 17
·2967
·
IF 5.719
Xiaohan Wang,Fan Zhang,Feiyue Hu,Yaya Li,Yongqiang Chen,Hailong Wang,Zhiyu Min,Rui Zhang
To solve the pollution problem of electromagnetic waves, new electromagnetic shielding materials should meet the requirements of being lightweight with high electrical conductivity. In this work, the combination of silver (Ag) nanoparticles and nitrogen doping (N-doping) was expected to tune the electromagnetic and physical properties of Ti3C2TxMXene, and the Ag@N-Ti3C2Txcomposites were fabricated through the hydrothermal reactions. The nitrogen doped (N-doped) Ag@Ti3C2Txcomposites showed a hollow structure with a pore size of 5 μm. The influence of N-doped degrees on the electromagnetic interference (EMI) shielding performance was investigated over 8–18 GHz. Therefore, the controlled N-doping composites exhibited reflection-based EMI shielding performance due to the electrical conductivity and the special three-dimensional (3D) honeycomb-like structure. The achieved average EMI shielding values were 52.38 dB at the X-band and 72.72 dB at the Ku-band. Overall, the Ag@N-Ti3C2Txfoam, due to its special 3D honeycomb-like structure, not only meets the characteristics of light weight, but also exhibits ultra-high-efficiency EMI shielding performance, revealing great prospects in the application of electromagnetic wave shielding field.Keywords:nitrogen doping;Ag@N-Ti3C2Txcomposites;honeycomb-like structure;electromagnetic interference;multi-reflections
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 SCIENCE & TECHNOLOGY
·
2024
·
IF 11.2
Mengjun Han,Di Lan,Zhiming Zhang,Yizhi Zhao,Jiaxiao Zou,Zhenguo Gao,Guanglei Wu,Zirui Jia
Reasonable manipulation of component and microstructure is considered as a potential route to realize high-performance microwave absorber. In this paper, micro-sized hexapod-like CuS/Cu 9 S 5 composites were synthesized via a facile approach involving the solvothermal method and subsequent sulfuration treatment. The resultant CuS/Cu 9 S 5 exhibited superb microwave absorbing capacity with a minimum reflection loss (RL min ) of -59.38 dB at 2.7 mm. The maximum effective absorption bandwidth (EAB max ) was 7.44 GHz (10.56-18 GHz) when the thickness was reduced to 2.3 mm. The outstanding microwave absorbing ability of CuS/Cu 9 S 5 composites is mainly related to its unique hexapod shape and the formation of heterogeneous interfaces. The unique hexapod shape significantly promotes the multi-reflection of the incident electromagnetic wave (EMW) increasing the attenuation path of EMWs in the material. Heterogeneous interfaces between CuS/Cu 9 S 5 enable powerful interface polarization, contributing to the attenuation of EMWs propagating in the medium. In addition, the EMW absorption performance of CuS/Cu 9 S 5 composites is also inseparable from the conduction loss. This study provides a strong reference for the research of EMW absorbent materials based on transition metal sulfides.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
RAPID COMMUNICATIONS IN MASS SPECTROMETRY
·
2024
·Vol. 38
·期 11
·e9742
·
IF 1.8
Shuxiong Yan,Yi Ren,Qi Huang,Yi Hong,Zhengge Chen,Mei Li,Bin Hu,Zhengxu Huang
Rationale Atmospheric pressure interface multi-reflection time-of-flight mass spectrometry (API-MRTOF-MS) has the potential to be a rapid and high-resolution analytical tool for versatile applications in chemistry, biology, environmental science, and medicine. Methods The ions were reflected in a mass analyzer via electrostatic mirrors and folded flight path. Therefore, flight distances were significantly increased. The ion flight path of the API-MRTOF-MS was extended from meters to over 1 km, and the mass resolution was increased. Furthermore, the mass analysis could be completed at around 10 ms due to the rapid response of TOF-MS. Results A high-resolution API-MRTOF-MS approach is successfully developed in this study. The mass resolution could achieve 116 050 (full widths at half maximum [FWHM]) for Cs + ions using an atmospheric pressure electrospray ionization within a total TOF of only 18 ms. An ion transmission efficiency of over 50% was achieved after 600 cycles. Conclusions The analytical performance of the newly developed API-MRTOF-MS demonstrated that it is suitable for high resolution and rapid analysis in many fields.
研究领域:
分析化学
·
质谱技术
·
环境科学
·
医学
✓ 已验证
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Yue Yu,Lian Wu,Shuxi Gao,Kangle Jia,Wei Zeng,Bing Liao,Hao Pang
Through inserting SiO 2 @Au into the reduced graphene oxide (rGO) layers, the rGO-SiO 2 @Au composites were prepared via the vacuum-assisted electrostatic self-assembly method. The obtained composites exhibit excellent electromagnetic interference (EMI) shielding effectiveness due to the successful construction of multi-nanocavities (spherical SiO 2 cavities and layered air cavities between rGO), multi-reflection interfaces (rGO and Au shell) and continuous conductive network (rGO-Au-rGO). Among them, the total shielding effectiveness (SET) of the composites with 75.78 wt% SiO 2 and 19.38 wt% rGO can reach 38.4 dB at 18 GHz. Thereinto, the shielding effectiveness absorption (SEA) is 36.4 dB, 1.3 and 13.5 times higher than that of rGO and SiO 2 @Au. And the shielding effectiveness reflection (SER) is always below 5 dB from 1 to 18 GHz, much lower than that of rGO (about 15 dB). Further studies found that the SEA values were enhanced at 12.6 GHz and 6.2 GHz due to the construction of cavities and location of Au nanoparticles between the rGO layers. This study provides a simple and mild method to prepare high-performance thin-layered materials with applications in the field of EMI absorption shielding.
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
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Jiawei Ding,Kai Song,Chuangchuang Gong,Chenxu Wang,Yue Guo,Chunsheng Shi,Fang He
High-performance electromagnetic (EM) absorbers are necessary for military and industry application in view of the extensive utilization of EM devices. Carbon fibers (CFs) have been considered as promising candidates in electromagnetic wave (EMW) absorption materials, while the single carbon fiber material cannot achieve satisfactory EMW absorption performance because of its limited impedance matching. Herein, electrodeposition and hydrothermal methods were used to fabricate vertical hollow ZnS nanoarrays on carbon cloth (CC) substrate, and then one kind of novel flexible EM composite absorbers with excellent performance was obtained through adjusting morphology of hollow ZnS nanoarrays by easily changing the synthesis parameters of the precursor. Noteworthy, the miniaturized cone-shaped hollow ZnS nanoarray composite absorber shows excellent EMW absorption performance of strong absorption and wide absorption band. The maximum reflection loss value is −52.5 dB and the effective absorption bandwidth reaches 5.1 GHz when the thickness is only 1.9 mm. At the same time, the composite possesses the characteristics of light weight and thin thickness. The excellent properties of the composite absorbers are mainly attributed to their morphological structure. The unique hollow ZnS nanoarray structure enhances the interface polarization and multiple reflections, meanwhile also giving it the properties of metamaterials with resonant absorption. Furthermore, the adjustment of the ZnS nanoarray morphology can not only change the transmission behavior of EMW but also affect the resonance frequency and intensity of the ZnS nanoarray unit. This study obtains high-performance absorbing materials with flexible characteristics as well as highlights the importance of the adjustment of the morphological structure to improve the EMW absorption performance.
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
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Yun Zhong,Jianbin Tang,Xin Zhang,Xinpeng Wei,Mengyao Li,Yujia Feng,Jian Wang
Aerospace, military and precision electronic equipment urgently need efficient, lightweight and durable flexible electromagnetic interference (EMI) shielding fabrics to shield electromagnetic radiation . Inspired by mussels, the corrugated PPTA@PDA@CoNiP composite material with multi-reflection interfaces was designed on the surface of poly para-phenylene terephthalamide (PPTA) fabric through efficient self-assembly of polydopamine (PDA) and electroless deposition Co-Ni-P. The ferromagnetic Co-Ni-P formed a strong interface adhesion with the fabric, and constructed a closed magnetic conductive network (saturation magnetization of 50.8 emu/g and resistance value around 150 mΩ), which enabled electromagnetic radiation to be reflected and absorbed. Hence, PPTA@PDA@CoNiP fabric sample exhibited excellent electromagnetic interference shielding effectiveness (EMI SE, 76.9 dB), absorption loss (SE A , 58.7 dB) and reflection loss (SE R , 18.2 dB) through the synergistic effect of electrical loss and magnetic loss in X-band. PPTA@PDA@CoNiP fabric retained good electrical conductivity even after repeated bending for 1000 cycles. In addition, the fabric still had certain air permeability after deposition of Co-Ni-P, and the Co-Ni-P layer showed excellent corrosion resistance . Meanwhile, this work provided an efficient and green approach for constructing an electromagnetic shielding layer on the surface of an inert fabric.
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）