Stretchable, Adhesive, Self‐healing, High‐efficiency Microwave Absorption by a Gel‐Like Single‐Component Poly(ionic liquid)

Abstract Fabrication of gel‐based microwave absorbers is an effective strategy for overcoming the shortcomings of conventional powder‐like absorbers, such as complicated processes and undesirable properties. However, the present gel‐based microwave absorbers generally consist of a polymer skeleton and a liquid dispersion medium and suffer from leakage of the dispersion medium. In this study, a novel gel‐like poly(ionic liquid) (PIL) microwave absorber with excellent properties is prepared. A maximum reflection loss (RL max ) of −58.8 dB GHz and an effective absorption bandwidth (EAB) of 10.56 GHz are achieved, which is mainly ascribed to high ionic conduction loss derived from lower glass transition temperature (T g ). Furthermore, the prepared PILs consisted of cationic imidazole‐containing alkoxy moieties as the polymer chain and bis(trifluoromethanesulfonyl) imide (TFSI − ) as the counter ion in the absence of a dispersion medium. The PILs displayed stretchability and adhesive and self‐healing abilities, thus providing a new candidate for developing high‐efficiency microwave absorbers for practical applications.