Elastomeric Foldable and High-Temperature Endurance Porous Graphene Films with Superior Electromagnetic Interference Shielding Performance

Abstract

Materials possessing multiple features of ultrathinness, flexibility and foldability, high-temperature resistance, and superb electromagnetic interference shielding performance are urgently needed for future portable and wearable electronics. Herein, highly flexible, robust, and porous graphene films (GFs) are controllably fabricated via a strategically combined chemical reduction with a rapid confined foaming approach. The spatially confined foaming at 500 °C in air endows the annealed GFs (AGFs) with integrated functionalities including a significantly improved surface smoothness, a lower sheet resistance, an elevated high-temperature endurance, a tailored hierarchical porous architecture, and elimination of iodine doping synchronous impurities. The resultant AGFs exhibit an excellent self-recovering elastic property, outstanding reliability during a large number of repetitive bending cycles, and remarkable flexibility and mechanical strength. More laudably, compared to the shielding effectiveness (SE) of GFs fabricated by individual HI reduction (28.63 dB) and thermal reduction (19.37 dB), the AGFs present a greatly improved SE up to a superior level of 48.37 dB due to the enhanced absorption of microwaves in the well-constructed highly conductive and hierarchical porous structure. Therefore, such thin AGFs possessing excellent flexibility and elasticity and high-temperature durability associated with superb shielding performance offer strong potential applications in the field of portable and wearable devices.