Multi‐Level Crosslinked Structure Fiber Composite Membrane With Multifunctional Properties: High Strength, Flexibility and EMI Shielding

Rational structural design remains a key challenge in developing multifunctional membranes with high strength, flexibility, and excellent electromagnetic interference shielding effectiveness (EMI SE). Herein, poly(vinyl alcohol-co-ethylene) (PVA-co-PE) nanofibers and UHMWPE fibers were used as the base material and the reinforced framework, respectively. The 2D reduced graphene oxide (RGO) and 1D silver nanowires (AgNWs) with a long-to-short aspect ratio were introduced into the fiber cross-network. Then, the obtained composite membrane was cross-linked with an electron beam (EB) under the action of a crosslinking agent, resulting in high strength, high EMI SE, and multifunctionality. Notably, the obtained membrane exhibited an excellent EMI SE of 50.3 dB, which was attributed to the excellent conductive network formed by the complementary physical forms of conductive fillers, achieving efficient conductive loss and multi-level reflection loss. Moreover, the synergistic effect of the crosslinked structure and hydrogen bonds largely increased the tensile strength to 19.7 MPa, and its environmental stability had also been significantly improved. Additionally, the obtained membrane also demonstrated outstanding thermal management and flexibly defined the surface saturation temperature. This work had guiding significance for further expanding its application in intelligent wearable electronic products and the thermal therapy fields.