Flexible, Stretchable, and Lightweight Hierarchical Carbon-Nanotube-Decorated Carbon Fiber Structures for Microwave Absorption

Abstract

Highly flexible, bendable, stretchable, and ultralightweight microwave absorbers (MA) that can handle harsh environments are essential for conformal surface coating in aerospace and defence industries. Hence, crystalline carbon nanotubes (CNTs) are grown on carbon fibers (CFs) using the chemical vapour deposition technique (CVD) and embedded in polyurethane (PU) to obtain MA. The fabricated MA is flexible, highly stretchable (>400%), has a low percolation threshold (0.1 wt %), ultralightweight (0.35 wt %), and thin nanocomposite for enhanced microwave absorber performance. The thickness of MA is optimized to achieve the impedance matching condition by utilizing the CST microwave studio simulation and verified experimentally. The minimum reflection loss (R L) of −52.53 dB with effective absorber bandwidth (EAB) covering the complete X band at a 2.4 mm thickness is obtained for just 0.35 wt % CFCNT. The negligible change in R L and EAB after 1000 bending cycles and 2 h of water-bath sonication confirms the operating efficiency of MA in harsh environmental conditions. The mechanism of microwave absorption in the case of CF and CFCNT-based MA is elucidated concerning microwave properties, electrical conductivity, and morphology. The CST microwave studio simulation is also extended from the X band to the Ku band (12.4–18 GHz) for broadband microwave absorber application.

Preparation of rGO/MoSe2 nanocomposites for enhanced microwave absorption of whole X and Ku bands

“…When C 0 is constant with increasing frequency, the magnetic loss is mainly from the eddy current loss, and when C 0 is variable, in addition to the eddy current loss, other mechanisms contribute to the magnetic loss. 42 As shown in Fig. 8, the value of C 0 for all the samples is almost constant in the whole frequency range.…”

Characterization of wheat husk-derived holey carbon/(RGO) x /CoFe2O4/PVA nanocomposites: insights into structural, optical, magnetic, and dielectric properties

“…Therefore, creating highly effective ferrite-based materials capable of absorbing EM waves remains a challenge. In recent years, scientists have focused on studying the interaction between ferrites and carbon-based materials such as carbon fibers, expanded graphite, graphene, RGO, and carbon nanotubes [23][24][25][26][27][28][29][30][31]. These substances possess remarkable qualities that make them ideal for the environment.…”