Ultrathin, biomimetic multifunctional leaf-like silver nanowires/Ti3C2Tx MXene/cellulose nanofibrils nanocomposite film for high-performance electromagnetic interference shielding and thermal management

Herein, we reported an ultrathin, flexible and super conductive silver nanowires (Ag NWs) doped Ti(3)C(2)Tx/Cellulose nanofibrils (CNFs) films by constructing biomimetic leaf-vein scaffolds via a facile vacuum-assisted filtration. Leaf-vein structure was built by Ti(3)C(2)Tx nanosheets and Ag NWs, offering numerous junctions and forming 3D conductive skeletons. The Ag NWs doped Ti(3)C(2)Tx/CNFs film with 85 wt% Ti(3)C(2)Tx and 5 wt% Ag NWs exhibited extremely high electrical conductivity and superior electromagnetic interference shielding effectiveness (EMI SE) value with a small thickness of 6 pm in X-bands (8.2-12.4 GHz). Synergetic effect on the mechanical property was observed for film with 70 wt% Ti(3)C(2)Tx and 10 wt% Ag NWs, exhibiting EMI SSE/t of 19,613.5 dB cm(2) g(-1), much higher than Ti(3)C(2)Tx/CNFs film. The electron migrating and hopping in the leaf-like conductive networks would lead to the massive ohmic and dielectric losses on the dipole-rich surface of Ti(3)C(2)Tx nanosheets. Additionally, the proof-of-concept of the proven film used as a Joule heater for thermal management was ascertained, which possessed fast response, aging stability, high-precision and ultralow voltage supply (1-3 V). Due to those preferential characteristics, the biomimetic Ag NWs doped Ti(3)C(2)Tx/CNFs materials can be integrated into the emerging applications, such as intelligent garments, thermotherapy and wearable devices. (C) 2020 Published by Elsevier B.V.