Porous polypyrrole Nanotube-Based Organohydrogels: Versatile materials for robust electromagnetic interference shielding in harsh environments

Wearable and multi-functional electromagnetic interference (EMI) shielding materials are an inevitable trend in order to cope with increasingly complex practical applications. In the present work, polypyrrole nanotube (PNT)-based organohydrogels (POGs) with excellent electromagnetic shielding effectiveness (SE) were synthesized through a facile sol–gel strategy. The obtained POGs offer distinct shielding performance, anti-drying, anti-freezing, plasticity and recyclable ability. The POG with a 20 wt% PNTs filling exhibits a SET of 63.6 dB in the X-band at a thickness of 2.0 mm. After being placed at ambient temperature for 30 days and − 40 ℃ for 4 h, its SE values still retained at 50.3 dB and 59.3 dB, respectively. Moreover, after being immersed in the solvents, the POG (left in the air for 30 days) can recover flexibility and 92 % of its original EMI shielding performance. Importantly, crushing the fully dried organohydrogels into the powder and placing it again in the solvents fully restores its flexibility and EMI shielding properties. The glorious shielding and mechanical characteristics can be ascribed to the superior conductivity of PNTs and the highly crosslinked stable network of PVA, as well as the further enhancement of the crosslinked network by cellulose nanofibers. In addition, ​sensors based on POGs can effectively detect human movement and strain deformations. This work thus provides fresh insight into exploring the sustainability of flexible and wearable EMI shielding materials for handling extreme environments.