Mechanical-dielectric optimized graphene aerogels with strain-tunable microwave attenuation and shielding functions†

Abstract

The widespread use of electronic devices significantly improves human activities but also raises concerns about microwave radiation pollution, creating a demand for materials that can effectively attenuate or shield against this radiation. To address this, we have developed innovative graphene aerogels (SCGAs) that incorporate SiC nanowires and carbon nanotubes, featuring a nature-inspired bridge-lamellar microstructure. These aerogels are optimized for both dielectric and mechanical properties, allowing for strain-tunable microwave attenuation and shielding functions. Specifically, our SCGAs demonstrate excellent microwave attenuation, with a minimum reflection loss of −51.6 dB and an effective attenuation bandwidth of 7.62 GHz, and can shift to a shielding mode with a shielding effectiveness of approximately 50.1 dB when compressed to 80%. This strain-responsive behavior remains stable over time, showing minimal degradation even after 1000 compression cycles, indicating exceptional long-term durability. Additionally, the strain-gradient strategy allows for customized low-reflection shielding applications, and the ceramic/carbon composition ensures superior resistance to harsh environmental conditions. Our research introduces a novel solution that provides effective microwave radiation protection across a broad frequency range and holds promise for various high-tech applications.