PDMS‐encapsulated liquid metal‐MXene aerogels for resilient electromagnetic wave absorption in harsh environments

Abstract This study serves as a guide to the development of a polydimethylsiloxane (PDMS)‐encapsulated liquid metal‐MXene aerogel, which has proven to be highly effective for electromagnetic wave absorption, particularly in saline environments. Through directional freezing and casting techniques, we have optimized the sample to exhibit enhanced absorption properties, achieving a reflection loss peak of −63.10 dB at 14.36 GHz. Variations in liquid metal content were found to significantly impact the complex permittivity of the aerogel, resulting in decreases observed in both real and imaginary components. This underscores the crucial role of conductivity in electromagnetic wave damping. Simultaneously, increases in tangent loss and attenuation constant highlight the vital contribution of MXene towards dissipating electromagnetic energy. Our best sample exhibits enhanced mechanical robustness, as evidenced by a high tensile modulus of 1 MPa. Notably, this exceptional performance is sustained for an extended period of 4 weeks even under harsh conditions such as high temperature, acid mist exposure, alkaline exposure, and immersion in synthetic seawater. By testing the thermal camouflage performance, samples achieved processable and efficient camouflage performance at multiple temperatures. This comprehensive dataset confirms the adaptability of the PDMS‐encapsulated liquid metal‐MXene aerogel as an effective solution for electromagnetic wave absorption in challenging environmental scenarios.