Luyang Liang,Ruishu Yang,Gaojie Han,Yuezhan Feng,Biao Zhao,Rui Zhang,Yaming Wang,Chuntai Liu
Two-dimensional Ti3C2Tx MXene-based hybrids-anchored magnetic metal nanoparticles show a huge potential application as effective wave absorbers due to the synergistic electromagnetic (EM) loss effect. In this work, uniform and size-controllable nickel, cobalt, or nickel–cobalt alloy nanoparticles were in situ grown on the surface of MXene via a facile and moderate co-solvothermal method for the first time. As an example, a nickel nanoparticles-anchored MXene (Ni@MXene) hybrid was homodispersed into dielectric polyvinylidene fluoride to develop its EM wave-absorbing capacity to a great extent. As expected, the results showed strong reflection loss (RLmin = −52.6 dB at 8.4 GHz), broad effective absorption bandwidth (EAB = 3.7 GHz including 71% of X-band), low loading (10 wt % Ni@MXene), and thin thickness (3.0 mm). By adjusting the sample thickness, EAB can cover completely the whole X-band with a maximum of 6.1 GHz, showing a huge potential of Ni@MXene hybrid applying as aircraft stealth coating. The mechanism analyses revealed that the excellent impedance matching, magnetocoupling effect, conductance, magnetic loss, and multiple scatterings contribute to the splendid EM wave-absorbing performance of the Ni@MXene hybrid. Considering the excellent overall performance, the Ni@MXene hybrid was identified as a promising candidate for EM wave absorption.
Jie Huang,Liuying Wang,Gu Liu,Weichao Wang,Chaoqun Ge,Haoke Yang,Xinyuan Jing,Bin Wang
With the rapid development of radar detection systems, the issue of electromagnetic wave stealth has become increasingly prominent. This paper presents a fabrication strategy for a composite material composed of CoFe 2 O 4 quantum dots in situ loaded onto CNTs through a multi-ligand combined thermal carbon shock, aiming to optimize multiple loss mechanisms for efficient electromagnetic wave absorption. The CoFe 2 O 4 quantum dots serve as loss centers, enhancing the heterogeneous charge distribution and the synergistic effects of magnetic resonance and magnetic exchange due to their supercritical size. Concurrently, the CNTs construct an efficient conductive network, providing a pathway for the free electrons within the CoFe 2 O 4 crystals and enhancing conductive loss. The composite achieves an effective bandwidth of 8.02 GHz and a maximum absorption of -52.7 dB at a filling ratio of only 25%, nearly covering the X and Ku bands. Furthermore, computer simulation techniques indicate that this coating exhibits excellent radar stealth performance on the F-22 Raptor fighter jet, presenting potential for the development and application of a new type of lightweight stealth coating.
In this study, a new lightweight one-dimensional absorber Co@NC@MoS 2 was designed and prepared. Firstly, polydopamine (PDA) was coated by oxidative self-polymerization with cobalt-nitrilotriacetic acid chelate nanowires (Co-NTAC) as template. Then core-shell structured magnetic hierarchical nanotubes (Co@PDA@MoS 2 ) were prepared by one-step hydrothermal method. After thermal annealing, PDA layer was transformed into nitrogen doped carbon layer (NC) to obtain the efficient microwave absorber Co@NC@MoS 2 . The removal of template and growth of MoS 2 were completed simultaneously, the preparation process was simplified. Because of its good magnetic loss and dielectric loss, Co@NC@MoS 2 shows excellent microwave absorption performance. Under filler content of 15 wt.%, the minimum reflection loss (RL min ) can reach -61.97 dB@9.2 GHz, and the effective absorption bandwidth (EAB) is 5.6 GHz. The electromagnetic parameters of Co@NC@MoS 2 can be further adjusted by changing the load of MoS 2 . Meanwhile, the structure and composition of Co@NC@MoS 2 were systematically analyzed. The influence of the microstructure on the microwave absorbing properties was investigated, and the microwave attenuation mechanism is revealed. As an efficient and lightweight absorber, Co@NC@MoS 2 has potential application value in the construction of new stealth coatings.
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