“Dual-armor” strategy to prepare multifunctional carbonyl iron particle with corrosion resistance, self-healing and high microwave absorbing performances

As a common and high microwave absorbing material, the application fields of carbonyl iron particle (CIP) are limited because of its poor corrosion resistance when working in harsh environments such as ocean, rainforest, or other high-humidity, high-salt places. Therefore, it is necessary to design a multifunctional CIP with good corrosion resistance and self-healing properties for ensuring its stable microwave absorbing performance. Herein, a "dual-armor" strategy is proposed to prepare multifunctional CIP (Composite particle), which is assembled with CIP coated by polyaniline (PANI/CIP) and Fe-DSe-M. Fe-DSe-M is Fe3+ responsive microcapsule whose shell contains -Se-Se- bonds and is magnetically adsorbed on the surface of PANI/CIP. PANI/CIP and Fe-DSe-M jointly undertake the function of microwave absorbing, anti-corrosion and self-healing. It is worth to note that the microwave absorbing performance of CIP after multi-functionalization has been greatly improved, and the minimum reflection loss value after accelerated corrosion is only reduced by 5.46 dB, which is much lower than PANI/CIP. These excellent properties of functional Composite particle benefit from PANI protective layer, Fe3+ responsive self-healing Fe-DSe-M and their synergistic effect. Our work provides a new approach to fabricate multifunctional microwave absorbing particle, which has a potential application in the corrosive environment.