Superb electromagnetic wave-absorbing composites based on large-scale graphene and carbon nanotube films

Abstract

AbstarctGraphene has sparked extensive research interest for its excellent physical properties and its unique potential for application in absorption of electromagnetic waves. However, the processing of stable large-scale graphene and magnetic particles on a micrometer-thick conductive support is a formidable challenge for achieving high reflection loss and impedance matching between the absorber and free space. Herein, a novel and simple approach for the processing of a CNT film-Fe3O4-large scale graphene composite is studied. The Fe3O4 particles with size in the range of 20–200 nm are uniformly aligned along the axial direction of the CNTs. The composite exhibits exceptionally high wave absorption capacity even at a very low thickness. Minimum reflection loss of −44.7 dB and absorbing bandwidth of 4.7 GHz at −10 dB are achieved in composites with one-layer graphene in six-layer CNT film-Fe3O4 prepared from 0.04 M FeCl3. Microstructural and theoretical studies of the wave-absorbing mechanism reveal a unique Debye dipolar relaxation with an Eddy current effect in the absorbing bandwidth.

Development of Nd (III)-Based Terahertz Absorbers Revealing Temperature Dependent Near-Infrared Luminescence

“…LF absorbing materials can lead to a breakthrough in THz technologies used in medicine for illegal substance detection, gas sensing in the event of accidents at fire sites or chemical plants, and quality checking of coated magnetic films or paints [ 33 , 34 ]. Furthermore, sub-THz detecting materials will be revolutionary in the development of next-generation wireless communication devices (beyond the fifth-generation 5G technology standard), as well as in the reduction in electromagnetic radiation pollution [ 35 , 36 , 37 ].…”

In-situ growth of Fe/Fe3O4/C hierarchical architectures with wide-band electromagnetic wave absorption

“…A perfect impedance match (Zin/Z0 = 1) indicates the incident EMW could achieve zero reflection at the front surface of the absorbent. Hence, a perfect impedance match between the absorbent and the incident EMW is critical for enhancing EMW absorption [9]. The coefficient of impedance match can be described as follows: [10] ⁄ = √ ⁄ tanh [ (2 √ ⁄ ] Eq.…”

Microbuckling-Enhanced Electromagnetic-Wave-Absorbing Capability of a Stretchable Fe3O4/Carbon Nanotube/Poly(dimethylsiloxane) Composite Film

“…Here, ethylenediamine coordinates with metal cations to form a stable complex and plays an important role in processing of the composites. In our previous work, the effect of the Fe 3 O 4 content on the final EM-wave-absorption performance was examined . In this research, we followed the optimized Fe 3 O 4 content.…”

“…Motivated by carbon-nanotube-film-based composites as lightweight wave absorbents and the creation of stretchable devices through microbuckling, − we demonstrate in this research, for the first time, a highly stretchable Fe 3 O 4 /carbon nanotube/poly­(dimethylsiloxane) composite for EM-wave-absorption application. The buckled structure of a Fe 3 O 4 /carbon nanotube/poly­(dimethylsiloxane) composite was fabricated by combining a Fe 3 O 4 /carbon nanotube film with a stretchable poly­(dimethylsiloxane) substrate using a stretching-then-releasing process.…”