Room temperature self-healing CIP/PDA/MWCNTs composites based on imine reversible covalent bond as microwave absorber

A novel room temperature self-healing carbonyl iron powder/ polydopamine@ multi-walled carbon nanotubes (CIP/PDA@MWCNTs) composites as microwave absorber covering the whole X frequency band were prepared in this study. In order to improve the impedance matching and dispersion of CIP in composites, it was encapsulated by PDA to form a core-shell structure. Meanwhile, the polydopamine modified carbonyl iron powder (CIP/PDA) was mixed with MWCNTs to enhance the performance of microwave absorption , so that the the composites possessed dielectric and magnetic losses. Moreover, the composites have self-healing property. When the content of CIP/PDA@MWCNTs is 20 wt%, the minimum reflection loss of the self-healing composites is −30.69 dB, and the bandwidth of RL less than -10 dB can reach up to 9.44 GHz, covering the entire X. Therefore, this room temperature self-healing CIP/PDA@MWCNTs composite will become an ideal microwave absorbing material for novel function device.