Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Enhanced microwave absorption performance of Fe₃Al flakes by optimizing the carbon nanotube coatings.

ABSTRACT: Fe₃Al is a good magnetic loss absorber for microwave absorption. However, due to the relatively high density and poor impedance matching ratio, the potential of Fe₃Al cannot be fully released. Herein, a dielectric loss absorber of carbon nanotubes (CNTs) is coupled with Fe₃Al to form Fe₃Al/CNTs composite absorbers. CNTs are randomly tangled and coated on the surface of the Fe₃Al flakes, forming a connecting conductive network. By carefully tuning the content of CNTs, the optimized Fe₃Al/CNTs composite absorber with 1.5% of CNTs can combine both magnetic loss and dielectric loss mechanisms, thus achieving an impedance matching ratio close to 1 while keeping strong attenuation for enhanced microwave absorption. As a result, an effective absorption bandwidth (RL ≤ -10 dB) of 4.73 GHz at a thickness of 2 mm is achieved.

SUBMITTER: Luo X

PROVIDER: S-EPMC10985793 | biostudies-literature | 2024 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Enhanced microwave absorption performance of Fe3Al flakes by optimizing the carbon nanotube coatings.

Luo Xixi X Xie Hui H Cao Jing J Lu Yaru Y Tao Shiping S Meng Zhixing Z Pu Lingna L Sun Liyang L He Pengjia P Liu Ziyan Z

RSC advances 20240301 15

Fe3Al is a good magnetic loss absorber for microwave absorption. However, due to the relatively high density and poor impedance matching ratio, the potential of Fe3Al cannot be fully released. Herein, a dielectric loss absorber of carbon nanotubes (CNTs) is coupled with Fe3Al to form Fe3Al/CNTs composite absorbers. CNTs are randomly tangled and coated on the surface of the Fe3Al flakes, forming a connecting conductive network. By carefully t ...[more]

PMID: 38567341

Similar Datasets

Hard Carbon Embedded with FeSiAl Flakes for Improved Microwave Absorption Properties.

Project description:Carbon-based composites have been proven to be strong candidates for microwave absorbers in recent years. However, as an important member, magnetic hard carbon (HC)-based composites have rarely been studied in the field of microwave absorption. In this study, HC embedded with FeSiAl (FeSiAl@HC) was synthesized by pyrolyzing a mixture of FeSiAl flakes and phenolic resin (PR). The as-synthesized HC-FeSiAl exhibited a layered structure, and the detailed microstructures were modified by changing the mass ratio of FeSiAl flakes and PR. Thus, the as-synthesized HC-FeSiAl exhibited tunable magnetic properties, wealthy functional groups, excellent thermal stability, and enhanced microwave absorption properties. The optimal minimum reflection loss is lower up to -36.1 dB, and the effective absorption bandwidth is wider up to 11.7 GHz. These results indicated that HC-FeSiAl should be a strong candidate for practical applications of microwave absorption, which may provide new insight into the synthesis of magnetic HC-based composites.

| S-EPMC9457624 | biostudies-literature

Microwave Absorption of α-Fe2O3@diatomite Composites.

Project description:A neoteric round sieve diatomite (De) decorated with sea-urchin-like alpha-type iron trioxide (α-Fe2O3) synthetics was prepared by the hydrothermal method and further calcination. The results of the electromagnetic (EM) parameters of α-Fe2O3-decorated De (α-Fe2O3@D) showed that the minimum reflection loss (RLmin) of α-Fe2O3@D could reach -54.2 dB at 11.52 GHz and the matched absorber thickness was 3 mm. The frequency bandwidth corresponding to the microwave RL value below -20 dB was up to 8.24 GHz (9.76-18 GHz). This indicates that α-Fe2O3@D composite can be a lightweight and stable material; because of the low density of De (1.9-2.3 g/cm3), the density of α-Fe2O3@D composite material is lower than that of α-Fe2O3 (5.18 g/cm3). We found that the combination of the magnetic loss of sea-urchin-like α-Fe2O3 and the dielectric loss of De has the most dominant role in electromagnetic wave absorption and loss. We focused on comparing the absorbing properties before and after the formation of sea-urchin-like α-Fe2O3 and explain in detail the effects of the structure and crystal shape of this novel composite on the absorbing properties.

| S-EPMC9409334 | biostudies-literature

Microwave Absorption of Crystalline Fe/MnO@C Nanocapsules Embedded in Amorphous Carbon.

Project description:Crystalline Fe/MnO@C core-shell nanocapsules inlaid in porous amorphous carbon matrix (FMCA) was synthesized successfully with a novel confinement strategy. The heterogeneous Fe/MnO nanocrystals are with approximate single-domain size which gives rise to natural resonance in 2-18 GHz. The addition of MnO2 confines degree of graphitization catalyzed by iron and contributes to the formation of amorphous carbon. The heterogeneous materials composed of crystalline-amorphous structures disperse evenly and its density is significantly reduced on account of porous properties. Meanwhile, adjustable dielectric loss is achieved by interrupting Fe core aggregation and stacking graphene conductive network. The dielectric loss synergistically with magnetic loss endows the FMCA enhanced absorption. The optimal reflection loss (RL) is up to - 45 dB, and the effective bandwidth (RL < - 10 dB) is 5.0 GHz with 2.0 mm thickness. The proposed confinement strategy not only lays the foundation for designing high-performance microwave absorber, but also offers a general duty synthesis method for heterogeneous crystalline-amorphous composites with tunable composition in other fields.

| S-EPMC7770782 | biostudies-literature

Enhanced Microwave Absorption Properties of α-Fe₂O₃-Filled Ordered Mesoporous Carbon Nanorods.

Project description:A novel kind of α-Fe₂O₃-filled ordered mesoporous carbon nanorods has been synthesized by a facial hydrothermal method. Compared with dendritic α-Fe₂O₃ micropines, both a broader effective absorption range-from 10.5 GHz to 16.5 GHz with reflection loss (RL) less than -10 dB-and a thinner matching thickness of 2.0 mm have been achieved in the frequency range 2-18 GHz. The enhanced microwave absorption properties evaluated by the RL are attributed to the enhanced dielectric loss resulting from the intrinsic physical properties and special structures.

| S-EPMC5452305 | biostudies-literature

Flexible Fe3Si/SiC ultrathin hybrid fiber mats with designable microwave absorption performance.

Project description:Flexible Fe3Si/SiC ultrathin fiber mats have been fabricated by electrospinning and high temperature treatment (1400 °C) using polycarbosilane (PCS) and ferric acetylacetonate (Fe(acac)3) as precursors. The crystallization degree, flexibility, electrical conductivity, dielectric loss and microwave absorption properties of the hybrid fibers have been dramatically enhanced by the introduction of Fe. Fe3Si nanoparticles with a diameter around 500 nm are embedded in SiC fibers. As the Fe3Si content increases from 0 to 6.5 wt%, the related saturation magnetization (M s) values increase from 0 to 8.4 emu g-1, and the electrical conductivity rises from 7.9 × 10-8 to 3.1 × 10-3 S cm-1. Moreover, the flexibility of Fe3Si/SiC hybrid fiber mats is greatly improved and remains intact after 500 times 180°-bending testing. Compared with pure SiC fibers, the Fe3Si/SiC hybrid fibers process higher dielectric and magnetic loss, which would be further advanced as more Fe3Si phase is introduced. At the optimal Fe3Si content of 3.8 wt%, the Fe3Si/SiC fibers/silicon resin composite (5 wt%) exhibits minimal reflection loss (RL) of -22.5 dB at 16.5 GHz and 2.5 mm thickness with a wide effective absorption bandwidth (EAB, RL < -10 dB) of 8.5 GHz. The microwave absorption performance can be further promoted by multi component stacking fiber mat composites which contain both low and high Fe3Si content layers. Furthermore, the position of the microwave absorption bands can also be simply manipulated by designing the stacking components and structure.

| S-EPMC9086545 | biostudies-literature

Lightweight Chain-Typed Magnetic Fe3O4@rGO Composites with Enhanced Microwave-Absorption Properties.

Project description:A lightweight microwave-absorbing material with a strong electromagnetic-absorption capability of practical significance in the field of electromagnetic compatibility was obtained by adjusting the ratio of Fe3O4 and rGO. A nanoparticle material with a chain-typed structure consisting of a combination of Fe3O4 and rGO was produced by a hydrothermal method under an applied magnetic field. The electromagnetic loss property of the Fe3O4@rGO composites is studied in the frequency range from 2 to 18 GHz. In addition, the reflection loss and the mechanism of microwave absorption are explored. By changing the amounts of rGO, the electromagnetic loss of the Fe3O4@rGO composites can be effectively regulated, which obtain better reflection loss. The minimum reflection loss of the Fe3O4@rGO composites is -49.4 dB at 16.2 GHz only with a thickness of 1.75 mm. Thus, the Fe3O4@rGO composites have an extremely thin thickness and a strong electromagnetic wave absorption capacity, which is a candidate for the development of lightweight magnetic absorbing materials.

| S-EPMC9612295 | biostudies-literature

Rational Construction of Hierarchically Porous Fe-Co/N-Doped Carbon/rGO Composites for Broadband Microwave Absorption.

Project description:Developing lightweight and broadband microwave absorbers for dealing with serious electromagnetic radiation pollution is a great challenge. Here, a novel Fe-Co/N-doped carbon/reduced graphene oxide (Fe-Co/NC/rGO) composite with hierarchically porous structure was designed and synthetized by in situ growth of Fe-doped Co-based metal organic frameworks (Co-MOF) on the sheets of porous cocoon-like rGO followed by calcination. The Fe-Co/NC composites are homogeneously distributed on the sheets of porous rGO. The Fe-Co/NC/rGO composite with multiple components (Fe/Co/NC/rGO) causes magnetic loss, dielectric loss, resistance loss, interfacial polarization, and good impedance matching. The hierarchically porous structure of the Fe-Co/NC/rGO enhances the multiple reflections and scattering of microwaves. Compared with the Co/NC and Fe-Co/NC, the hierarchically porous Fe-Co/NC/rGO composite exhibits much better microwave absorption performances due to the rational composition and porous structural design. Its minimum reflection loss (RLmin) reaches - 43.26 dB at 11.28 GHz with a thickness of 2.5 mm, and the effective absorption frequency (RL ≤ - 10 dB) is up to 9.12 GHz (8.88-18 GHz) with the same thickness of 2.5 mm. Moreover, the widest effective bandwidth of 9.29 GHz occurs at a thickness of 2.63 mm. This work provides a lightweight and broadband microwave absorbing material while offering a new idea to design excellent microwave absorbers with multicomponent and hierarchically porous structures.

| S-EPMC7770714 | biostudies-literature

Preparation of porous Fe2O3 nanorods-reduced graphene oxide nanohybrids and their excellent microwave absorption properties.

Project description:In this paper, α-Fe2O3 nanoparticles (NPs)-reduced graphene oxide (RGO), α-FeOOH nanorods (NRs)-RGO and porous α-Fe2O3 NRs-RGO could be selectively synthesized by hydrothermal method. The investigations indicated that the obtained α-Fe2O3 NPs, α-FeOOH NRs and porous α-Fe2O3 NRs were either attached on the surface of RGO sheets or coated uniformly by the RGO sheets. And the as-prepared nanohybrids exhibited excellent microwave absorption performance, which was proved to be ascribed to the quarter-wavelength matching model. The optimum reflection loss (RL) values for α-Fe2O3 NPs-RGO, α-FeOOH NRs-RGO and porous α-Fe2O3 NRs-RGO were ca. -32.3, -37.4 and -71.4 dB, respectively. Moreover, compared to the obtained α-Fe2O3 NPs-RGO and α-FeOOH NRs-RGO, the as-prepared porous α-Fe2O3 NRs-RGO nanohybrids exhibited enhanced microwave absorption properties because of their special structure and synergetic effect. The possible enhanced microwave absorption mechanisms were discussed in details. Our results confirmed that the geometrical morphology had a great influence on their microwave absorption properties, which provided a promising approach to exploit high performance microwave absorbing materials.

| S-EPMC5593864 | biostudies-literature

Environment-Stable CoxNiy Encapsulation in Stacked Porous Carbon Nanosheets for Enhanced Microwave Absorption.

Project description:Magnetic/dielectric@porous carbon composites, derived from metal-organic frameworks (MOFs) with adjustable composition ratio, have attracted wide attention due to their unique magnetoelectric properties. In addition, MOFs-derived porous carbon-based materials can meet the needs of lightweight feature. This paper reports a simple process for synthesizing stacked CoxNiy@C nanosheets derived from CoxNiy-MOFs nanosheets with multiple interfaces, which is good to the microwave response. The CoxNiy@C with controllable composition can be obtained by adjusting the ratio of Co2+ and Ni2+. It is supposed that the increased Co content is benefit to the dielectric and magnetic loss. Additionally, the bandwidth of CoNi@C nanosheets can take up almost the whole Ku band. Moreover, this composite has better environmental stability in air, which characteristic provides a sustainable potential for the practical application.

| S-EPMC7770751 | biostudies-literature

Facile Fabrication of Three-Dimensional Lightweight RGO/PPy Nanotube/Fe3O4 Aerogel with Excellent Electromagnetic Wave Absorption Properties.

Project description:In this article, a three-dimensional chemically reduced graphene oxide/polypyrrole nanotubes (PPy nanotubes)/Fe3O4 aerogel (GPFA) was fabricated by a simple one-step self-assembly process through hydrothermal reduction. The addition of both PPy nanotubes and Fe3O4 nanoparticles is aimed to avoid the aggregation of graphene sheets, effectively adjust the permittivity, and make better impedance matching between dielectric loss and magnetic loss of the composite aerogel to gain excellent electromagnetic (EM) wave absorption performance. The EM wave-absorbing results indicate that the ternary composite with an ultralow density of about 38.3 mg/cm3 shows an improved EM wave-absorbing property with a maximum reflection loss of -49.2 dB at the frequency of 11.8 GHz, with an effective absorption bandwidth below -10 dB reaching 6.1 GHz (9.8-15.9 GHz) at a thickness of 3.0 mm. Such an outstanding EM wave absorption behavior can be attributed to the multiple reflections, polarizations, and relaxation processes in the aerogel.

| S-EPMC6641692 | biostudies-literature