A simple and reliable route to prepare high-temperature microwave high-performing absorbers

Abstract

With extensive use of electronic devices and communication equipment, serious issue of electromagnetic wave pollution needs to be addressed as one of the priorities that demand social efforts. In this work, carbon black (CB)/SiO2 composites were synthesized via facile and reliable route and applied for microwave absorption at high-temperature environment around 673 K. Variations of complex permittivity and microwave absorption performance of composites under X-band of 8.2–12.4 GHz and temperature range of 298–673 K were analyzed in detail. Results showed that complex permittivity improved continuously with the increase in CB content and temperature. By elevating the temperature to 673 K, the composite with 10 wt.% of CB can achieve full coverage of effective absorption (RL <− 10 dB) over X-band with thin thickness of 2.9 mm. Therefore, this new composite material has good application prospect as high-temperature microwave absorber, considering its extraordinary properties and easy preparation.