Rapid and conformal manipulation of electromagnetic wave absorption through smart shape memory composite form Chen Qian 1 , Ding Wang 2 , Weikun Zhao 1 , Wentong Yang 1 , Zhuofan Qin 2 ,Yaofeng Zhu 1* , Ben Bin Xu 2* 1 School of Materials Science & Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, P. R. China, 2 Department of Mechanical and Construction Engineering, Northumbria University, Newcastle Upon Tyne, UK With the development of communication and electronic technologies, smart electromagnetic wave (EMW) absorption materials are highly desired in various applications. However, the performance of ordinary EMW absorption materials is determined by their electromagnetic parameters, which are constant unless the composition changes. To meet the requirements in tunability of performance, this study presents a porous EMW absorption material with adjustable effective absorption bandwidth and reflection loss (RL). A composite foam is first fabricated by assembling reduced graphene oxide (rGO) to the melamine sponge (MS) framework. The prepared MS/rGO shows high flexibility, elasticity, and low density of 10.7 mg/cm3, and reaches the minimum RL of -63.29 dB with effective bandwidth of 7.18 GHz at a thickness below 4 mm. Furthermore, thermoplastic polyurethane (TPU) is introduced and endows the MS/rGO with thermolysis property. Tunable EMW absorbing performance of MS/rGO-TPU is achieved through the shape memory effect with shape fixity ratio and recovery ratio of approx. 100%. The effective absorption bandwidth of MS/rGO-TPU can be adjusted in a wide range from 5.5 to 18 GHz (covers most of C band with whole X and Ku band) upon compression deformation, which can be modulated by cooling/heating. The minimum RL can be switched from -15.4 to -39.2 dB, as well as the absorption peak shifting from 6.8 to 13.9 GHz. In summary, the lightweight MS/rGO and smart MS/rGO-TPU with adjustable performance for EMW absorption are expected to provide various options in complex electromagnetic applications.
P62
© The Author(s), 2023
Made with FlippingBook Learn more on our blog