Transparent and flexible electromagnetic interference shielding film based on Ag nanowires/ionic liquids/thermoplastic polyurethane ternary composites

Abstract

Flexible and transparent electromagnetic interference (EMI) shielding films are desired in various fields. Herein, we propose a simple but effective approach to fabricate the flexible, transparent, and high EMI shielding films based on Ag nanowires (AgNWs)/ionic liquids (ILs)/thermoplastic polyurethane (TPU) ternary composites. Attributed to the formation of the low-density but highly interconnected AgNW network as well as the synergistic effect of AgNWs and ILs on composite conductivity, the as-prepared AgNWs/ILs/TPU film has a transmittance of 67% and an EMI shielding effectiveness of ∼26.8 dB at 10 GHz. Because of the low areal density of AgNWs, the absolute shielding effectiveness (SSE/t) of AgNWs/ILs/TPU film even reaches to 1.32 × 106 dB cm2 g−1 at 10 GHz, which is superior to most reported works. More interestingly, the as-prepared film also exhibits good durability and stability in the EMI shielding properties even after 1000 uninterrupted bending cycles or long-term soaking in acidic or alkali solution. These outstanding performances endow the as-prepared film with great potential in flexible and transparent EMI shielding scenarios.