Microcapsule-type multifunctional microwave absorbing material with self-warning and corrosion resistance performances

The corrosion and damage from the environment directly reduce the lifespan of metal-based absorbing materials, severely limiting their widespread application. Designing a novel system to promptly alert against corrosion, subsequently offer corrosion inhibition after the alert to create a window for artificial repair of the materials, this would be a completely new approach. Herein, a “microcapsule-type” multifunctional absorbing material (CIP-M) is obtained. CIP-M is composed of self-warning and anticorrosive core material, Fe 3+ responsive inner shell, and microwave absorbing CIP particles outer shell. The multifunctional CIP-M in coating (CIP-M-EP) exhibits a significant fluorescence self-warning effect under 254 nm light in the early stages of corrosion. Meaningfully, thanks to the 3D CIP core–shell structure, the maximum reflection loss of CIP-M-EP is up to −35.96 dB, much higher than other coatings. Meantime, once corrosion occurs, the corrosion resistance properties of CIP-M greatly inhibit further the attack by the corrosion medium. CIP-M-EP coating maintains higher impedance modulus at 0.01 Hz and microwave absorbing performances during the first 45 days of corrosion, providing sufficient time for artificial repair of the coating. More interestingly, CIP-M also endows materials with good flexibility, anti-counterfeiting, and information encryption functions. These effective extend the application fields of CIP-M.