Polymer-bubbling for one-step synthesis of three-dimensional cobalt/carbon foams against electromagnetic pollution

Improved Microwave Absorption Performance with Sustainable Porous Carbon/Carbon Nanotube Composites

“…The synthesis parameters, such as polymerization reaction and the carbonization process assisted the formation of porous on a microscale range. These pores are characteristics of carbon foams [49][50][51] and are normally analyzed by mercury intrusion-extrusion curves.…”

Composition Optimization and Microstructure Design in MOFs-Derived Magnetic Carbon-Based Microwave Absorbers: A Review

“…As we discussed above, the basic principle of EM absorption is to dissipate EM energy through the interruption of electric or magnetic field branch, and thus, dielectric loss and magnetic loss are widely considered to be two dominant mechanisms for EM absorption [ 31 ]. Dielectric loss usually originates from conductivity loss and polarization loss, where conductivity loss realizes energy consumption through the directional movement of some residual carriers in dielectric medium driven by an applied electric field [ 41 ]. Compared with conductive loss, polarization loss has more diversified modes, namely, electronic polarization, ionic polarization, dipole orientation polarization, and interfacial polarization [ 7 ].…”

“…However, ionic polarization and electronic polarization do not work the attenuation of EM waves in gigahertz range due to their extremely short relaxation time (10 –12 –10 –16 s) and elastic nature, that is, dipole orientation polarization and interfacial polarization are active to afford the consumption of EM energy in most cases. Dipole orientation polarization is induced by the hysteretic reorientation of dipoles along with an applied electric field, and interfacial polarization depends on the asymmetrical accumulation of space charges at heterogeneous interfaces, which can generate an electric dipole moment and bring energy consumption [ 41 ]. In view of above facts, high conductivity, abundant electric diploes, and sufficient heterogeneous interfaces are very conductive to strong dielectric loss.…”

“…Apart from hollow microstructure in microwave absorbers, three-dimensional macroporous microstructure has also been recognized to be greatly helpful for the consumption of EM energy [ 11 , 41 , 147 , 148 ]. However, it is very difficult to create such a profitable microstructure just by a direct pyrolysis of MOFs.…”

1D CNT-Expanded 3D Carbon Foam/Si3N4 Sandwich Heterostructure: Utilizing the Polarization Compensation Effect for Keeping Stable Electromagnetic Absorption Performance at Elevated Temperature

“…It is commonly recognized that carbon materials exhibit obvious structure-dependent interfacial effects . Among different structures, 3D foam/aerogel structures show significant potential for overcoming the challenges related to lightweight and strong absorption due to their extremely high porosity and interactive network, and the excellent EM absorbing properties could be achieved that tightly associated with the successful construction of the specific 3D foam/aerogel architecture. , The inner CF acts as the basement of the porous structure to achieve a larger interface contact and provide necessary conductive loss. On this basis, we choose CNTs as the common and representative nano-medium to construct nano-interfaces between coating layers, which can be formed in situ during the carbonization process, and their lightweight characteristic is beneficial for the application of EAMs.…”