High-performance microwave absorption of flexible nanocomposites based on flower-like Co superstructures and polyvinylidene fluoride

Abstract

Flower-like Co superstructures were synthesized via a facile hydrothermal process at low temperature; then the flexible Co/PVDF nanocomposites were prepared by combining the Co nanocrystal with a polyvinylidene fluoride (PVDF) matrix. The Co/PVDF hybrids exhibit distinct microwave absorption properties in the range of 2-18 GHz. With filler loading of 25 wt%, the minimum reflection loss reaches À38.9 dB at 6.4 GHz as the thickness is 2.5 mm. The frequency bandwidth less than À10 dB covers from 4.64 to 10.56 GHz by adjusting the weight content from 15 wt% to 40 wt%. The possible microwave absorbing mechanism has been also discussed in detail.

Fe3O4@Carbon@Polyaniline Trilaminar Core–Shell Composites as Superior Microwave Absorber in Shielding of Electromagnetic Pollution

“…Fe 3 O 4 /carbon composite nanofibers were prepared by carbonizing electrospun polyacrylonitrile/magnetic Fe nanoparticles . Fe 3 O 4 –graphene, Fe 3 O 4 –carbon nanotube composites have also been reported as excellent shielding materials. , Despite high-performance microwave absorption, synthetic process of these materials are relatively more complex . The presence of low content of magnetic nanoparticles in all these composites lead to lower complex permeability. − This is followed by decrease in dielectric loss unfavorable for impedance matching, i.e., microwave absorption .…”

MWCNTs as Conductive Network for Monodispersed Fe3O4 Nanoparticles to Enhance the Wave Absorption Performances

“…With the rapid development of wireless communication tools, local area networks, and the widely applications of electronic devices, electromagnetic (EM) interference, and radiation have caused serious electromagnetic pollution, which brings great threats to information safety and people's health . Considerable attention has been aroused in recent years with the aim of solving this increasingly serious problem by converting EM energy into thermal energy . Due to different mechanism of propagation of EM waves, EM wave absorbers can be classified to resistor type, dielectric type, and magnetic medium type.…”

Electromagnetic wave absorption properties of ternary poly(vinylidene fluoride)/magnetite nanocomposites with carbon nanotubes and graphene

“…These nanocomposites provide merits of light weight, flexibility and cost effectiveness. For polymer matrix, there are various options such as polyaniline (PANI), polypyrrole (PPy) and poly(vinylidene fluoride) (PVDF), which have been extensively used for the manufacture of microwave absorbers [7][8][9]. Ferrites [10], spinel-type ferrites [11], and metallic magnetic materials [12] are the typical magnetic nanomaterials inclusions which have been widely studied.…”