Materials
·
2020
·Vol. 13
·期 23
·5331
·
IF 3.057
Yue Yuan,Shicheng Wei,Yi Liang,Bo Wang,Yujiang Wang
Cobalt ferrite is synthesized via a simple solvothermal method. Then, the effect of the degree of cobalt-ferrite growth on its morphology, structure, electromagnetic performance, and microwave absorption is studied as a function of the solvothermal reaction time. When the reaction time during synthesis is 8 h, the structure of cobalt ferrite is hollow spheres. In addition, when the reaction time is 12 h and 16 h, it becomes a submicron sphere with a diameter of 100–150 nm. With the increase of reaction time, cobalt ferrite underwent the process of cobalt ferrite formation, hollow structure formation, hollow structure disappearance, agglomeration separation and reagglomeration in 4–16 h. In general, CoFe2O4-8h shows better microwave absorption-the effective absorption bandwidth is 9.84 GHz (6–15.84 GHz) for a thickness of 1.72–3.72 mm. This represents a minimum return loss of −47.24 dB. A better understanding of both the synthesis parameters and the relationship between structure and electromagnetic properties can open new possibilities for applications and the development of microwave absorbing materials.Keywords:cobalt ferrite;reaction time;structure;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
COMPOSITES SCIENCE AND TECHNOLOGY
·
2019
·
IF 6.309
Qixin Yang,Yiyuan Shi,Yu Fang,Yubing Dong,Qingqing Ni,Yaofeng Zhu,Yaqin Fu
A novel ternary nanocomposite of Fe 3 O 4 functionalized porous biomass carbon decorated by aligned polyaniline (A-PANI/Fe 3 O 4 /PBC) was successfully fabricated by hydrothermal and in situ oxidative polymerization. The morphology and structure of the composite was characterized by X-ray diffraction, fourier transform infrared spectra, scanning electron microcopy, transmission electron microscopy , X-ray photoelectron spectra and vibrating sample magnetometer . The microwave absorbing properties of A-PANI/Fe 3 O 4 /PBC composite were investigated in the frequency of 2–18 GHz. The results indicated that the A-PANI/Fe 3 O 4 /PBC composite possess excellent microwave absorbing performance, and the minimum reflection loss can be up to −44.8 dB at 10.67 GHz, effective absorbing bandwidth ( RL < −10 dB) reaches 4.69 GHz with a thickness of 2.7 mm. The excellent microwave absorbing performance of composite was mainly related to the multi-loss mechanisms, good impedance matching, synergistic and geometrical effect of porous biomass carbon, magnetic particles and aligned PANI.
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
·
2024
·Vol. 59
·期 31
·14313-14327
·
IF 3.5
An Boyuan,Zhang Dongjie,Liu Yuyan,Fan Zhimin,Tan Huifeng,Xie Zhimin
Ti 3 C 2 T x (MXene)-based composites are considered electromagnetic wave absorption (EMA) materials due to their dielectric properties, microstructure, and synergistic interactions with magnetic particles. A better understanding of the effect of the MXene content in composites on the EMA performance is essential for their application, yet it remains unclear. Here, MXene/PU@Fe 3 O 4 (MPF) microspheres with different MXene contents were produced through the incorporation of magnetic particles and multiple electrostatic self-assembly processes. The results show that when the molar ratio of MXene to Fe 3 O 4 is less than 0.5:1, the EMA performance of the MPF microspheres gradually increases with increasing MXene content. MPF microspheres exhibit the best EMA performance when the molar ratio of MXene to Fe 3 O 4 is 0.5:1, with a maximum reflection loss (RL) of 44.0 dB and an effective absorption bandwidth (EAB) of 2.30 GHz. Further increases in this ratio led to an increase in the EAB but a slight reduction in the maximum RL. Additionally, the combination of the same MXene and Fe 3 O 4 nanoparticle ratio had no significant effect on the EMA performance. We expect that this work will enrich the EMA performance research on MXene-based composites.
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
·
2018
·
IF 3.057
Mingxu Sui,Tianqi Fu,Xiaodong Sun,Guangzhen Cui,Xuliang Lv,Guangxin Gu
Unary and binary M 2+ (M=Mn, Co, Ni, Zn) substituted hollow Fe 3 O 4 were prepared by one-step solvothermal method. The crystallographic structure, morphology, element components and microwave absorbing properties of as-prepared products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), Energy-dispersive X-ray (EDX) and vector network analyzer (VNA). The unary and binary Co 2+ substitution of hollow Fe 3 O 4 could result in a significant improvement of microwave absorption performance, including the expanding of effective absorption bandwidth, the thinner thickness and the increment of absorbing intensity. The sample of CoFe 2 O 4 could reach an optimal reflection loss of − 28.78 dB at 15.52 GHz under the thickness of 1.5 mm, moreover, the efficient absorption bandwidth (less than −10 dB) is expanded to 5.56 GHz which is most outstanding among these samples. The minimum reflection loss of Co 0.75 Zn 0.25 Fe 2 O 4 could reach − 49.60 dB at 9.88 GHz under the thickness of 2 mm. The as-prepared products could be used as microwave absorber with the advantages of strong absorption, broad bandwidth and thin thickness. The favorable performance could be attributed to the strong magnetic loss, dielectric loss and good impedance matching properties.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Li Dong,Xiangdong Liu,Zhengrong Xiong,Dekun Sheng,Changhong Lin,Yan Zhou,Yuming Yang
We first reported a strategy to prepare functional poly(vinylidene fluoride) (PVDF) membranes with excellent ultraviolet-absorbing property through chemically induced grafting. Herein, the polymerizable ultraviolet (UV) absorber 2-hydroxy-4-(3-methacryloxy-2-hydroxylpropoxy) benzophenone (BPMA) made by ourselves was grafted onto the PVDF chains that have been pretreated with tetraethylammonium hydroxide (TEAH) alkaline solution. Moreover, the effect of experiment conditions such as the alkali and monomer concentrations, alkali treatment time on the UV-absorbing property of the obtained PVDF-g-PBPMA membranes were studied in detail. The chemical structure of the modified membranes was confirmed by 1 H NMR, FT-IR and XPS measurements. Meanwhile, the thermal and UV-absorbing properties were characterized by TGA, DSC and UV-Vis spectrophotometer, respectively. The results indicated that BPMA side chains were successfully introduced onto PVDF backbones. Most importantly, the obtained PVDF-g-PBPMA membranes exhibited excellent UV-absorbing property. The transmittance of UV light at 300 nm decreased to as low as 0.02% and the UV light below 388 nm could be completely absorbed by the PVDF-g-PBPMA membrane made under optimal condition.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
CARBON
·
2020
·
IF 8.821
Xiaochuang Di,Yan Wang,Yuqiao Fu,Xinming Wu,Ping Wang
Thin and lightweight absorbers with strong absorption capacity are future development directions in the field of electromagnetic wave (EMW) absorption. Based on two microwave-absorbing mechanisms, the three-dimensional (3D) porous carbon materials derived from wheat flour were prepared via pyrolysis carbonization . Then, ZnFe 2 O 4 nanospheres were synthesized and distributed on the surface of carbon skeleton by simple solvothermal method. Results showed that microwave absorption performance was significantly improved due to synergistic effects between ZnFe 2 O 4 nanospheres and carbon matrix. With absorber thickness of only 1.8 mm and low filler loading of 20 wt%, the minimum reflection loss could reach as low as −54.1 dB at 14.1 GHz. The widest effective absorption bandwidth ranged from 9.2 GHz to 15.0 GHz (5.8 GHz) with a thickness of 2.5 mm when the filler loading was 10 wt%, covering 36% of entire measured bandwidth. As an absorber, 3D porous carbon@ZnFe 2 O 4 composite exhibited ideal microwave absorption properties because of synergistic effects between dielectric and magnetic loss, well-matched impedance, interfacial polarization , Debye relaxation process as well as multiple reflection and scattering. Considering excellent EMW absorption performance, the porous carbon@ZnFe 2 O 4 composite fabricated by a simple method can provide a new inspiration for designing structure and composition of lightweight microwave 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
APPLIED ENERGY
·
2018
·
IF 7.9
Min Xiao,Helei Liu,Hongxia Gao,Wilfred Olson,Zhiwu Liang
In this work, nonaqueous binary absorbents were investigated for CO 2 capture by mixing conventional amines (i.e. monoethanolamine MEA, methyldiethanolamin MDEA) and ionic liquids. Four ionic liquids [BMIM]BF 4 , [BEIM]BF 4 , [BPIM]BF 4 and [BBIM]BF 4 were synthesized. The thermal stability of the ionic liquids was evaluated and viscosity was measured over the temperature range of 298–348 K. The CO 2 absorption performance of the pure ionic liquids was studied at ambient pressure and compared with the hybrid absorbents. The influence factors including temperature, stir rate and cycling numbers were then investigated. Finally, the CO 2 absorption mechanism was verified using NMR spectroscopy. Results showed that additional amine could greatly promote the CO 2 absorption performance of ionic liquids and mixed absorbents revealed different CO 2 absorption behavior depending on the amine type. This work proved that the mixed absorbent MDEA + [BEIM]BF 4 yields high cycling CO 2 capacity, energy saving, good regenerability and especially, low viscosity.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2021
·
IF 5.467
Hengdong Ren,Sheng Wang,Wei Lian,Jialin Ma,Yan Zhao,Yin Liu,Ling Bing Kong,Tian shu Zhang,Won-Chun Oh
Palygorskite (Pal) was used as frameworks to disperse Fe 3 O 4 and polyaniline (PANI) nanoparticles for the preparation of coral-like Pal-dispersed Fe 3 O 4 /PANI composites with improved electromagnetic absorption performance. The processing was a combination of hydrothermal synthesis and simple mechanical stirring. With increasing content of Pal, specific surface area of the Pal-dispersed Fe 3 O 4 /PANI composites was increased from 21.14 m 2 /g to 29.69 m 2 /g, while the composites exhibitd fluffy coral-like structure due to the cation exchange mechanism and rich silanol (Si-OH) group of Pal. Since various loss mechanisms and improved impedance matching , the Pal-dispersed Fe 3 O 4 /PANI displayed an optimal reflection loss of −62.45 dB and a broad effective absorption bandwidth of 5.05 GHz. Therefore, this work develops an inexpensive framework to disperse nanoparticles for electromagnetic absorption materials , while new application of Pal is proposed.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Jiabao Zang,Haifeng Li,Qingzhi Zhu,Ziheng Wang,Hubuli Bazaerbieke,Li Sun,Meijie Zhang
There are few reports about the electromagnetic wave (EMW) absorption properties of α−SiC based composites, and almost all of them focus on β−SiC polymorphs. In this study, α−SiC p /α−SiC nw /SiO 2 /C hybrid composites (sample SiC−C1500) with heterostructure α−SiC nanowires (α−SiC nw ) of multiple interfaces 4H−SiC/6H−SiC/SiO 2 /C were successfully prepared using mixed powder (α−SiC+m−SiO 2 +C) as raw material based on the heterogeneous nucleation−growth mechanism, and their microwave absorption properties were investigated. Meanwhile, the samples SiC−V2150 and Si−C1500 were obtained by vacuum calcination (α−SiC+m−SiO 2 +C) at 2150 0 C and carbothermal reduction (Si+m−SiO 2 +C) at 1500 0 C, respectively, and their phase compositions were α−SiC p /C and β−SiC p /β−SiC nw /SiO 2 /C, respectively. The sample SiC−C1500 exhibited excellent EMW absorption properties, with a minimum reflection loss (RL min ) value of −18.37 dB at a thickness of 1.3 mm, and a maximum effective absorption bandwidth (EAB max ) value of 4.9 GHz at a thickness of 1.5 mm. In contrast, the EMW absorption performance of the samples SiC−V2150 and Si−C1500 was obviously poor, which was consistent with the RCS (Radar Cross−Section) simulation results. The formation of α−SiC p /α−SiC nw /SiO 2 /C composites (sample SiC−C1500) containing 4H−SiC/6H−SiC/SiO 2 /C multi-interfaces heterostructure α−SiC nanowires (α−SiC nw ) was analyzed. The excellent EMW absorption performance of SiC−C1500 sample could be attributed to the effective regulation of α polymorphs, nanowire heterostructure, multi−component hybridization. This study supplies a helpful experience and reference for improving the high temperature EMW absorption performance of SiC matrix composites.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
Discover Nano
·
2024
·Vol. 19
·期 1
·1-8
·
IF 0
Xiong Yuanpeng,Wu Bo,Lin Yuanzhi,Zhang Mingwen,Chen Jintian
In this study, a simple route for the synthesis of hierarchical W 18 O 49 assembled by nanowires is reported. The morphologies and formation of W 18 O 49 single-crystal could be controlled by changing the concentration of WCl 6 -ethanol solution. This synthesis strategy has the advantages that the hierarchical W 18 O 49 microspheres could be economic synthesized at 180 °C without adding additives. Furthermore, efficient optical absorption properties in ultraviolet, visible and near-infrared region were obtained for the hierarchical W 18 O 49 microspheres comparing with nanowires. These results will further promote the research of tungsten-based oxide nanomaterials. Graphical abstract
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Kai Wang,Zhenying Liu,Shouwu Huang,Jiayi Song,Shaofeng Dong,Tingting Pan,Qiaoyuan Wang,Yin Liu
Ni 0.2 Mn 0.4 Zn 0.4 Fe 2 O 4 (NMZF) nanoparticles were anchored on the surface of MXene(Ti 3 C 2 T x ) to form Ti 3 C 2 T x /NMZF nanocomposites for optimization of microwave absorption performance. The Ti 3 C 2 T x /NMZF nanocomposites were synthesized by using a four-step strategy, including sonication, stirring, hydrothermal reduction and vacuum drying. More than 40 percent of the NMZF nanoparticles in this nanocomposite were assembled to form a conductive network. Meanwhile, the multilayer MXene acted as a framework to host the NMZF nanoparticles, providing dipolar polarization, interfacial polarization and eddy current loss. Benefiting from the structure design of MXene, combined with magnetic materials and optimized impedance matching, the Ti 3 C 2 T x /NMZF exhibited a minimum reflection loss (RL min ) of −57.39 dB, with a thickness of 2.97 mm and an effective absorption bandwidth (EAB) of 3.2 GHz. Therefore, such a facile method could be used to construct nanocomposites with microwave absorption performance (-57.39 dB, 3.2 GHz), so as to address microwave pollution issues.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2025
·
IF 5.3
Runfen Zheng,Lixin Wei,Yuxin Bai,Jianfei Man,Jian Ye,Huiping Zhang,Yihan Wang
To address the issues of poor regeneration performance and high regeneration energy consumption associated with traditional CO2 absorbents, the development of novel phase-change absorbents has become a key area of research. In this study, a new phase-change absorbent system, DEGDEE-AEEA-AMP, is developed, using N-(2-hydroxyethyl)ethylenediamine (AEEA) as the main absorbent, bis(2-ethoxyethyl)ether (DEGDEE) as the phase-separation agent, 2-amino-2-methyl-1-propanol (AMP) as the activator, and water as the solvent. The performance of this system is compared with that of monoethanolamine (MEA) at a 30% mass concentration, which serves as the reference standard. The study includes absorption, desorption, corrosion, cyclic absorption–desorption experiments, and regeneration energy consumption estimations. The results indicate that the volume of the rich phase in the DEGDEE-AEEA-AMP (DAP) system constitutes 56.7% of the total volume. When the AMP mass fraction is 15%, the absorption capacity reaches 2.52 mol·kg–1, which is 14.0% higher than that of MEA. The maximum desorption rate is 13.19 × 10–3 mol·kg–1·s–1, which is 3.39 times higher than that of MEA. The minimum regeneration energy consumption is 2.742 GJ·t–1 CO2, representing a 29.9% reduction compared to 30% MEA. The corrosion rate of the rich liquid is 0.230 mm/a, 1.32 times that of MEA, but it can be significantly reduced by adding anhydrous Na2SO3. When the AMP mass fraction is 15%, the DAP phase-change absorbent system exhibits high absorption and desorption performance, good cyclic stability, and lower regeneration energy consumption.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子