High electromagnetic wave absorbing performance of activated hollow carbon fibers decorated with CNTs and Ni nanoparticles

High Electromagnetic Waves Absorbing Performance of a Multilayer‐Like Structure Absorber Containing Activated Carbon Hollow Porous Fibers–Carbon Nanotubes and Fe3O4Nanoparticles

“…Figure c is the magnified SEM image of CNTs grown on the surface of ACHFs. As shown in Figure c, the CNTs are dense on the substrate which results in higher loss of incident microwave because of the formation of “trunk‐branch” structures . The vertical section of CNTs–ACHFs–Fe 3 O 4 is displayed in Figure d, it suggests that the hollow carbon fiber is filled with Fe 3 O 4 /epoxy.…”

“…Many ways have been studied to shield electromagnetic waves, and at present, the most effective means of shielding electromagnetic waves and controlling electromagnetic interference is to use electromagnetic waves absorbing materials . As we all know, advanced absorbing materials must possess the characteristics of thin thickness, light weight, strong absorptive capacity and environmental adaptability, and broad absorption band (“thin, light, strong, and broad”) …”

“…According to electromagnetic waves absorbing theories, the structure of absorbents can also play an important role in absorbing performance. “Trunk‐Brand‐Fruit” structure has exhibited excellent electromagnetic wave absorbing performance . However, its absorbing bandwidth of is still needed to be broaden.…”

Microstructural changes of polyacrylonitrile-based carbon fibers (T300 and T700) due to isothermal oxidation (1): focusing on morphological changes using scanning electron microscopy

“…7 shows the cross-section of carbon fibers before and after isothermal oxidation. The cross-sectional observations revealed hollow cores in the longitudinal direction after isothermal oxidation, similar to the shape of hollow fibers [19,20]. According to the model proposed by Barnet and Norr [21], the crystallinity weakens towards the center of PANbased carbon fibers.…”

Absorption of electromagnetic waves in sandstone saturated with brine and nanofluids for application in enhanced oil recovery

“…The dielectric materials can absorb the EM waves incident on them in synchronized frequencies which results in the polarization and the magnetoelectric coupling and later dissipate the energy [40]. However, some of the disadvantages which restrict their broad applications are narrow EM frequency bandwidth, poor mechanical properties and low environmental adaptability [41,42]. The factors which affect the absorbing properties of materials are the materials complex permittivity ε , complex permeability μ and dielectric losses δ [43].…”