Janus nanocellulose composite films with superior electromagnetic interference shielding and dual-thermal management

Constructing multifunctional conductive composite films with excellent electromagnetic interference (EMI) shielding properties, Joule heating and solar heating meet the demands of the communications industry, artificial intelligence and wearable smart devices. Furthermore, high-performance EMI shielding materials which can endure to harsh conditions have attracted significant attention of researchers. Herein, silver nanowires (AgNWs) were prepared by glycol reduction method and then combined with bamboo cellulose nanofiber (BCNF). At the same time, polyaniline (PANI) was polymerized in situ on the surface of BCNF, and a series of Janus structure BCNF-AgNWs/BCNF-PANI composite films were prepared by vacuum assisted filtration and vapor deposition. The composite film exhibited excellent electrical conductivity of 16,618 S cm^-1 and EMI shielding effectiveness of 103.2 dB, and could be adapted to harsh environments. Moreover, it also had good Joule heating performance (saturation temperature up to 152.0 °C at 1.5 V applied voltage) and photothermal conversion performance (saturation temperature up to 165.1 °C at 1.5 W cm^-2 power density irradiation), showing fast response time and good heating stability. The Janus composite film had a good application prospect in the field of EMI shielding and dual-drive heating.