Janus-structured nanocomposite films constructed with Ca2+ bridging TOCNF/CNTs networks for enhancing electromagnetic shielding and mechanical properties

With the advancement of 5G communications, the Internet of Things (IoT), and wearable electronics, there has been an increasing demand for lightweight, flexible, and high-performance electromagnetic interference (EMI) shielding materials. In this study, AgNWs/TOCNF/CNTs* nanocomposite films with Janus structure were successfully prepared by vacuum-assisted filtration followed by hot pressing. The film consisted of a conductive silver nanowire (AgNWs) layer and a supporting TOCNF/CNTs* layer. Specifically, the electromagnetic shielding and mechanical properties were effectively enhanced by constructing a three-dimensional (3D) network within the TOCNF/CNTs* layer through ionic crosslinking between Ca 2+ ions and carboxylate anions (−COO − ). Comprehensive characterization demonstrated that the film possessed excellent mechanical strength (tensile strength of 93.92 ± 3.20 MPa), superior electrical conductivity (67,114 S/m), outstanding EMI shielding effectiveness (EMI SET of 63.70 dB, EMI SEE/t exceeding 10,284 dB·cm 2 /g, and a shielding efficiency of 99.999957 %), as well as rapid Joule heating response under low voltage (2.0 V, reaching 115.60°C within less than 6s). These properties underscore the film’s strong potential for applications in portable electronics, aerospace, and military technologies.