Flexible MXene/Cellulose Nanofiber Aerogels for Efficient Electromagnetic Absorption

Advanced electromagnetic (EM) wave absorbing materials with maintained performance after deformation are technologically important with the ever-developing flexible electronic devices. In this study, MXene/cellulose nanofiber (Ti3C2Tx/CNF) aerogels have been fabricated via selective etching and freeze-drying, and the effect of Ti3C2Tx content on the evolution of EM wave absorption properties has been revealed. The addition of the Ti3C2Tx MXene nanosheets constructs an extensive network for enhanced conductive loss and interfacial polarization, together with satisfactory impedance matching over a wide frequency range. Optimal absorption can be achieved with 50.0 wt MXene, exhibiting a minimum reflection loss (RLmin) of -44.9 dB and a broad effective absorption bandwidth (EAB) of 5.7 GHz at a thickness of 2.0 mm. After SO cycles of bending deformation, the Ti3C2Tx/CNF aerogels exhibit maintained performance due to the porous structure for stress dilution and the interlayer slipping benefiting from the existence of the Ti3C2Tx nanosheet. As such, this work provides not only an effective strategy to design flexible EM wave absorbers with excellent performance but also insights into the evolution of absorption performance after multiple deformations.