Intelligent microwave absorption of VO2@PDA/RGO composites based on dynamic interfacial polarization performance

Abstract

To design smart microwave-absorbing materials (MAMs), it is essential to adjust the corresponding electrical conductivity and dielectric parameters according to variable conditions. However, it is still challenging to concurrently adjust the effective absorbing intensity and frequency range in MAMs due to their interdependent constraints. Here, we developed intelligent MAMs by incorporating core–shell structure vanadium dioxide @ polydopamine (VO2@PDA) powders as polarization loss units, while the subwavelength-sized reduced graphene oxide microspheres (RGOms) were used as conduction loss units. When the temperature is higher than the metal–insulator phase transition temperature of the insulator state VO2 (M), the corresponding metal state VO2 (R) could be produced, which, therefore, contributes to an enhanced interfacial polarization loss due to the significant electrical performance differences between the VO2 (R) and the PDA shell. As an optimized result, the changes of the effective absorption frequency band (▵EAF) and reflection loss (▵RL) of the RV3 composite could be approximately 1.5 GHz and 24 dB, respectively, attributable to the phase transition of VO2. This study provides a novel approach for the adjustment of electromagnetic responses based on dynamic interfacial polarization performance, which offers broader prospects for developing next-generation smart electromagnetic absorption devices with both reversible microwave absorption frequency range and intensities.