Hierarchically porous polyimide/Ti3C2Tx film with stable electromagnetic interference shielding after resisting harsh conditions.

Polymer-based conductive nanocomposites are promising for electromagnetic interference (EMI) shielding to ensure stable operations of electronic devices and protect humans from electromagnetic radiation. Although MXenes have shown high EMI shielding performances, it remains a great challenge to construct highly efficient EMI shielding polymer/MXene composite films with minimal MXene content and high durability to harsh conditions. Here, hierarchically porous polyimide (PI)/Ti3C2Tx films with consecutively conductive pathways have been constructed via a unidirectional PI aerogel­assisted immersion and hot-pressing strategy. Contributed by special architectures and high conductivities, PI/Ti3C2Tx films with 2.0 volume % Ti3C2Tx have high absolute EMI shielding effectiveness up to 15,527 dB cm2 g−1 at the thickness of 90 µm. Superior EMI shielding performance can be retained even after being subjected to hygrothermal or combustion environments, cryogenic (−196°C) or high (250°C) temperatures, and rapid thermal shock (∆T = 446°C), demonstrating high potential as high-performance EMI shielding materials resisting harsh conditions.