Thermally Conductive TiCT Fibers with Superior Electrical Conductivity.

High-performance TiCT fibers have garnered significant potential for smart fibers enabled fabrics. Nonetheless, a major challenge hindering their widespread use is the lack of strong interlayer interactions between TiCT nanosheets within fibers, which restricts their properties. Herein, a versatile strategy is proposed to construct wet-spun TiCT fibers, in which trace amounts of borate form strong interlayer crosslinking between TiCT nanosheets to significantly enhance interactions as supported by density functional theory calculations, thereby reducing interlayer spacing, diminishing microscopic voids and promoting orientation of the nanosheets. The resultant TiCT fibers exhibit exceptional electrical conductivity of 7781 S cm and mechanical properties, including tensile strength of 188.72 MPa and Young's modulus of 52.42 GPa. Notably, employing equilibrium molecular dynamics simulations, finite element analysis, and cross-wire geometry method, it is revealed that such crosslinking also effectively lowers interfacial thermal resistance and ultimately elevates thermal conductivity of TiCT fibers to 13 W m K, marking the first systematic study on thermal conductivity of TiCT fibers. The simple and efficient interlayer crosslinking enhancement strategy not only enables the construction of thermal conductivity TiCT fibers with high electrical conductivity for smart textiles, but also offers a scalable approach for assembling other nanomaterials into multifunctional fibers.