Highly conductive, hydrophobic, and acid/alkali-resistant MXene@PVDF hollow core-shell fibers for efficient electromagnetic interference shielding and Joule heating

To endow transition metal carbide (MXene) fibers with satisfactory chemical resistances, high electrical conductivity and enhanced ductility, multifunctional hollow core-shell fibers with ductile polyvinylidene fluoride (PVDF) shell and compactly ordered MXene hollow core are fabricated with a coaxial wet-spinning assembly strategy. The partial hydroxylation of the PVDF occurred during the coagulation in the presence of ammonium hydroxide enhances the interfacial interaction of the PVDF layer with the MXene layer. The hollow core consisting of compact and ordered MXene layer provides the fibers with a high electrical conductivity of 3.08 × 105 S m−1, while the PVDF shell endows the fibers with enhanced ductility and excellent resistances to acid, alkali, and seawater. The hollow core-shell structure makes the fiber lightweight, and facilitates multiple scattering of electromagnetic waves, resulting in increased electromagnetic wave absorption and attenuation. The ductile and conductive textile made of the hollow core-shell fibers with a 6 μm-thick MXene layer exhibits a high electromagnetic interference shielding effectiveness of ∼60 dB. Moreover, the resultant fibers exhibit exceptional Joule heating performances for human thermal management. The high conductivity, enhanced ductility, strong chemical resistances, and satisfactory Joule heating properties make the hollow core-shell fibers promising for electromagnetic interference shielding and wearable heating applications.