Magnetic-dielectric synergy and interfacial engineering to design yolk–shell structured CoNi@void@C and CoNi@void@C@MoS2 nanocomposites with tunable and strong wideband microwave absorption

Morphology control of eco-friendly chitosan-derived carbon aerogels for efficient microwave absorption at thin thickness and thermal stealth

“…In addition, the loss by the absorber predominantly derived from interface polarization loss between paraffin wax and absorbing material, dipole polarization and conduction loss; particularly, the defects in the microstructure of the absorber can easily develop the polarization point. 68 Conductive loss mainly depends on the highly graphitized carbon network, which is beneficial to the jumping and transmission of electrons in materials. In general, the excellent EMA characteristics of the absorber are caused by various loss mechanisms.…”

Architecture inspired structure engineering toward carbon nanotube hybrid for microwave absorption promotion

“…Figures 3 A–3E show the microwave absorbing performance contours with changing thickness of samples over the frequency range of 2–18 GHz, which are obtained on the basis of the transmission line theory ( Liu et al., 2012 ; Li et al., 2022a , 2022b ): where Z in and Z 0 represent the input impedance of absorber and the impedance of free space successively, t is the thickness of absorber, and c is the velocity of light. As exhibited, the minimum RL (RL min ) of only −13.60 dB for pristine AC shows its poor intrinsic MA performance, while pristine CNTs exhibit no effective absorption at all.…”

“…Additionally, on one hand, the dipolar polarization raised by the directional arrangement of dipole under the alternating electromagnetic field ( Liang et al., 2020 ) is one of the critical origins of dielectric relaxation considering the characteristics of heteroatoms doping and defect-ridden structure of N-AC/CNTs. On the other hand, based on the Maxwell–Wagner effect, the heterogeneous interfaces of solid/solid and solid/air provide abundant sites where charges accumulate ( Qin et al., 2022 ; Li et al., 2022a , 2022b ), by which interfacial polarization loss is induced. Moreover, considering their ultra-low permeability and magnetic loss factor (tan δ M ) ( Figure S9 ) as well as the ever-changing coefficient C 0 ( Figure S10 ), the magnetic loss of hybrids can be basically neglected when compared to dielectric loss.…”

Hydrogel-based composites beyond the porous architectures for electromagnetic interference shielding

“…Apart from typical carbon materials [114][115][116][117], some emerging biopolymers have also been applied to promote the construction of aligned porous architectures. For instance, green and renewable nanocellulose is widely recognized for its high strength-to-weight ratio, large aspect ratio, and large specific surface area.…”