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

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.