Self-Healing Composites with Heterogeneous Interfaces and Electromagnetic Synergy for Electromagnetic Wave Absorption

The usage of electronics has led to the issue of electromagnetic wave pollution, and the demand for materials that can absorb electromagnetic waves is increasing. The longevity of materials may be impacted by damage caused during use. Here, a composite strategy with efficient electromagnetic wave absorption and self-healing through induction heating is proposed. Ni/PUF/PU@ER (NPPE), Cu/Ni/PUF/PU@ER (CNPPE), and Ni/PANI/PU@ER (NPAPE) microcapsules with magnetic and conductive characteristics were prepared by interface polymerization, in situ polymerization, and electroless plating methods. Their superior mechanical and thermal durability guarantee the long-term stability of the healing agent. The minimum reflection loss of the composite with NPAPE is -54.62 dB at 1.85 mm, and the effective absorption bandwidth (EAB) is 3.95 GHz. Additionally, the EAB reaches 4.32 GHz at 1.93 mm, surpassing the RLmin and EAB values of the majority of similar materials. Due to the exceptional electromagnetic synergy of NPAPE, the composite exhibits the most outstanding induction heating performance. The material reaches 68.3 °C within 10 min, which is higher than the temperatures of the other two materials. Furthermore, the crack area of the composite significantly reduces, demonstrating excellent quick self-healing characteristics for damage. This novel strategy is conducive to promoting the development of the circular economy and can introduce a worthwhile research direction into the field of electromagnetic wave absorption.