Egg white-derived carbon/magnetic nanoparticles/water-soluble graphene oxide composite with homogeneous structure as an excellent electromagnetic wave absorber

Abstract

An egg white-derived carbon/magnetic nanoparticles/water-soluble graphene oxide composite absorber (EWC/MNPs/WSGO) was specially designed and synthesized via a facile sol-gel process with subsequent high-temperature pyrolysis. Magnetic nanoparticles (MNPs) were used to...

In situ growth of CoNi bimetallic alloys inside polyetheretherketone-derived hierarchical porous carbon as a broadband and efficient electromagnetic wave absorber

“…Generally, the real part ( ε ′ and μ ′) and the imaginary part ( ε ′′ and μ ′′) are associated with the storage and dissipation capabilities of electromagnetic energy, respectively. 13,28 As shown in Fig. 8a and b, both ε ′ and ε ′′of the three samples show a decreasing trend with increasing frequency, exhibiting a typical frequency dispersion behavior.…”

“…[4][5][6] So far, numerous EMW absorbing materials with certain absorption performances have been prepared, including carbon materials, 7 nonmagnetic metal particles, 8 magnetic particles, 9 conducting polymers, 10 semiconductors, 11 cer-amics, 12 and their composites. 13 However, the devised materials have some shortcomings in terms of EMW absorbing properties due to various reasons such as weak attenuation ability, narrow effective bandwidth, and thick matching thickness. Therefore, according to the requirements for practical application, there is an urgent need to develop high-efficiency EMW absorbing materials with characteristics of strong attenuation, wide frequency range, and thin thickness.…”

Quadrangular cone carbon-constructed effective 3D network for a lightweight and broadband microwave absorbent

“…According to the transmission line theory, the RL values of the products with different thicknesses were calculated by the following equation to evaluate their EMA performance: [33][34][35][36] RL ðdBÞ ¼ 20 log 10…”

“…According to the transmission line theory, the RL values of the products with different thicknesses were calculated by the following equation to evaluate their EMA performance: 33–36 where Z in is the input impedance of the absorber, Z 0 is the impedance of free space, c is the velocity of electromagnetic waves in free space, d is the thickness of the absorber, and f is the frequency of the electromagnetic waves. Generally, RL values less than −10 dB mean that more than 90% of the EMW energy can be absorbed.…”

Facile Preparation of Light‐Weight Polyetheretherketone/Graphite/FeCo Ternary Heterogeneous Composite Foam with High Compressive Strength and Excellent Integrated Electromagnetic Wave Absorption Performance

“…It can be understood as the leading role of dielectric loss from the excessive addition of graphite, causing the magnetic loss to form an excellent impedance match difficultly. In addition, the attenuation capacities are also a decisive point to affect RL, according to the Equation (), [ 62 ] the calculated α of the PEEK/C/FeCo composite foams are revealed in Figure S4c, Supporting Information. It is obvious that all the composite foams have strong EMW attenuation capability and the α value steadily increases with increasing frequency.…”