Flexible, Reliable, and Lightweight Multiwalled Carbon Nanotube/Polytetrafluoroethylene Membranes with Dual‐Nanofibrous Structure for Outstanding EMI Shielding and Multifunctional Applications

Abstract In this study, lightweight, flexible, and environmentally robust dual‐nanofibrous membranes made of carbon nanotube (CNT) and polytetrafluoroethylene (PTFE) are fabricated using a novel shear‐induced in situ fibrillation method for electromagnetic interference (EMI) shielding. The unique spiderweb‐like network, constructed from fine CNTs and PTFE fibrils, integrates the inherent characteristics of these two materials to achieve high conductivity, superhydrophobicity, and extraordinary chemical resistance. The dual‐nanofibrous membranes demonstrate a high EMI shielding effectiveness (SE) of 25.7–42.2 dB at a thickness range of 100–520 µm and the normalized surface‐specific SE can reach up to 9931.1 dB·cm 2 ·g −1 , while maintaining reliability even under extremely harsh conditions. In addition, distinct electrothermal and photothermal conversion properties can be achieved easily. Under the stimulation of a modest electrical voltage (5 V) and light power density (400 mW·cm −2 ), the surface temperatures of the CNT/PTFE membranes can reach up to 135.1 and 147.8 °C, respectively. Moreover, the CNT/PTFE membranes exhibit swift, stable, and highly efficient thermal conversion capabilities, endowing them with self‐heating and de‐icing performance. These versatile, flexible, and breathable membranes, coupled with their efficient and facile fabrication process, showcase tremendous application potential in aerospace, the Internet of Things, and the fabrication of wearable electronic equipment for extreme environments.