Compressible Fe₃O₄/MWCNTs-coated polymer foams for high-performance and tunable electromagnetic microwave absorption

Highly Deformable Porous Electromagnetic Wave Absorber Based on Ethylene–Propylene–Diene Monomer/Multiwall Carbon Nanotube Nanocomposites

“…Among the initial studies, Yang et al [5] developed polystyrene foams obtaining shielding efficiencies (SE) around 20 dB with 15 wt.% and 7 wt.% carbon nanofibers and nanotubes, respectively. Subsequent works improved the SE or decreased the loading fractions required to achieve commercially attractive EMI shielding materials (around 20 dB in the X-band region (8.2-12.4 GHz)) and mostly looked at thermoplastic or rigid thermoset matrices or coated the foam surfaces with conductive nanofillers [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. These previous studies have demonstrated that the development of the cellular structure causes the redistribution of the nanoparticles, decreasing the average gap between the nanoparticles along the cell walls, thus enhancing the electrical conductivity and EMI shielding properties [9,14].…”

Porous carbon materials for microwave absorption

“…Recently, carbon foams (CFs) or carbon aerogels with open-hole network structures have attracted great attention as potential microwave absorbers due to their advantages such as low density, outstanding electrical transport property, high surface area and excellent mechanical stability. 60,61,[118][119][120][121][122][123][124] Unfortunately, pure PC-based foams/aerogels are seriously limited by their strong conductivities, resulting in poor impedance matching. It is vital to integrate them with other materials to tune the electromagnetic parameters and impedance matching.…”

“…after pyrolysis. 61,119,124 The post-treatment method can be further divided into two types. One is to obtain a PC foam by pyrolysis of the foam precursor, and then modify the PC foam.…”

Magnetic foams from polyurethane and magnetite applied as attenuators of electromagnetic radiation in X band

“…[6,7] The addition of polymers with intrinsic magnetic and dielectric loss loads, within a given frequency range of interest, has been one of the techniques used for the elaboration of low density ERAM. Polymer additives with carbonaceous fillers such as graphite particles, carbon black, carbon fibers or conductive polymers and metal powders leads to dielectric absorptive materials, while the addition of additives with magnetic characteristics, for example the magnetic particles of Fe 3 O 4 , spherical iron carbonyl, and ferrite materials [8,9,10,11,12,13,14] has given rise to magnetic ERAM.…”