Unleashing multifunctionality: Janus-structured flexible CNT-based composite film with enduring superhydrophobicity and excellent electromagnetic interference shielding

Versatile electromagnetic interference (EMI) shielding films are crucial for electronics and wearables. We acid-functionalize CNTs and load them with Fe3O4, and then fabricate Janus-structured Fe3O4@CNTs/ bacterial cellulose (BC)/ silver nanowires (AgNWs) composite films using layer-by-layer vacuum filtration and hot pressing. Benefiting from the rational regulation of component proportions and the design of a Janus structure, the composite film with a thickness of only 90 μm exhibits outstanding shielding effectiveness (SE) of 68.68 dB in the X-band, owing to the mechanism of absorption-reflection-reabsorption. Moreover, 1H,1H,2H,2H-Perfluorodecyltrimethoxysilane, and ethyl orthosilicate are utilized to synthesize fluoroalkyl-grafted silica nanoparticles (F-SiO2) and coated onto the film’s upper surface using spray technique, rendering it superhydrophobicity (150°