Carboxylate-Decorated Multiwalled Carbon Nanotube/Aramid Nanofiber Film for Tunable Electromagnetic Interference Shielding Performance and Rapid Electric Heating Capacity

Ultrathin and multifunctional films are highly desirable for pivotal technological demands in current society. However, the nanoscale structural design and fabrication control of these functional films are still underdeveloped and challenged. Herein, carboxylate-decorated multiwalled carbon nanotube (c-MWCNT)/aramid nanofiber (ANF) films were fabricated via vacuum-assisted filtration, followed by hot-pressing. With a c-MWCNT content of 50 wt %, the hybrid film exhibited a tensile strength of 57.13 MPa and an electrical conductivity of 708.9 S·m–1. The c-MWNCT/ANF film also possessed exceptional electromagnetic interference (EMI) shielding performance, whose EMI shielding effectivness (SE) and specific SE (SSE/t) value reached 19.68 dB and 5624.03 dB·cm2·g–1 in the X band at a thickness of 37 μm, respectively. In addition, the c-MWNCT/ANF film with 50 wt % c-MWNCT loading demonstrated stable electric heating performance, whose surface temperature was higher than 180 °C at a supplied voltage of 10 V. Moreover, the layered structure of the c-MWNCT/ANF film possessed a low voltage drive of 2 V and a high heating rate of 3.5 °C·s–1. The tunable EMI shielding capacity, low voltage drive, and high heating rate endowed the c-MWNCT/ANF film with great potential for smart garments, EMI shielding management, and personal thermal management systems.