Janus-structured MXene composite films with tannic acid-enhanced strength and environmentally stable electromagnetic interference shielding

Abstract

Driven by the increasing deployment of electronic devices in harsh environments, the development of electromagnetic shielding materials with both environmental stability and mechanical robustness has become critical to ensuring device reliability and data integrity. In this study, MXene was functionalized with tannic acid to impart antioxidant properties, and Janus-structured MXene-TA/AgNWs/ANF (J-MTAgA) composite films were fabricated via a layer-by-layer vacuum-assisted filtration technique. The Janus-structured composite films exhibited significantly superior overall performance compared to their directly blended counterparts. The J-MTAgA film with a MXene-TA to AgNWs ratio of 1 : 9 exhibited high electrical conductivity of 5501 S cm⁻¹, along with an excellent electromagnetic interference (EMI) shielding effectiveness (SE_T) of 90.5 dB and a specific shielding effectiveness (SSE/t) of 21 611 dB cm² g⁻¹. In addition, the J-MTAgA film with an MT/Ag ratio of 1 : 9 exhibited excellent mechanical performance, achieving a tensile strength of 89.5 MPa, 1062.34% higher than that of the pristine MXene film. Notably, the J-MTAgA film demonstrated exceptional environmental durability, maintaining an EMI SE_T of 89.8 dB after 300 days of storage at room temperature, with a negligible reduction of only 0.8%. These features make the J-MTAgA film a promising candidate for electromagnetic shielding in portable intelligent devices and precision electronics.