Intelligent Off/On switchable electromagnetic wave absorbing material based on VO2 nanowires

With the development of modern communication devices, the demand for intelligent electromagnetic wave (EMW) absorbing materials that dynamically respond to environmental changes is ever-growing. However, the design and fabrication of high-performance EMW absorbing materials with adapt features remains challenging. Here, we report a temperature-responsive composite comprising VO2 nanowires (NWs) and polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP). Benefiting from the phase transition characteristics of VO2 and the high aspect ratio of NWs, the composite demonstrates two distinct off/on switchable EMW absorbing performances as the temperature increases at low filler loading of VO2. The composite with 10 wt% VO2 NWs transitions from transmission to absorption, showcasing a maximum change in reflection loss (RL) and effective absorption bandwidth (EAB) values of 53.09 dB and 4.85 GHz at the thin thickness of 2.5 mm and 2 mm, respectively. While the composite with 30 wt% VO2 NWs shows a switch from absorption to reflection with the highest ΔEAB and ΔRL values of 3.59 GHz (1.5 mm) and 44.29 dB (2.5 mm), respectively. Additionally, radar cross-sectional (RCS) simulations verify the intelligent EMW absorbing performance of the composite. The work provides an effective and sustainable approach to harness the potential of VO2 for developing tunable and high-performance wave-absorbing materials.