Interfacial Confinement Derived High‐Strength MXene@Graphene Oxide Core‐Shell Fibers for Electromagnetic Wave Regulation, Thermochromic Alerts, and Visible Camouflage

Although electrically conductive Ti₃C₂T_x MXene fibers are promising for wearable electronics, the poor inter-sheet interactions and the random stacking structure of MXene sheets seriously hinder electron transport and load transfer of the fibers. Herein, mechanically strong and electrically conductive MXene@graphene oxide (GO) core-shell fibers are fabricated with a coaxial wet-spinning methodology for electromagnetic wave regulation, thermochromic alerts, and visible camouflage. During the coaxial wet-spinning, the trace-carboxylated GO sheets in the shell align readily because of the spatial confinement of the coaxial needle, while the MXene sheets in the core are progressively oriented and flattened because of the spatial confinement of the GO shell. The positively charged chitosan in the coagulating solution enhances the interfacial interactions between the GO and MXene sheets and facilitates the sheet's orientation inside the fibers. Consequently, the highly aligned core-shell fibers exhibit an ultrahigh tensile strength of 613.7 MPa and an outstanding conductivity of ≈7766 S cm^-1. Furthermore, fiber-woven textiles not only offer excellent electromagnetic interference shielding performance but also achieve quantitative regulation of electromagnetic wave transmission by adjusting the angle of the double-layered textiles. The textiles can combine with thermochromic coatings for thermotherapy alerts, visual thermochromic warnings, and visible camouflage.