General In Situ Dynamic Trawling of Functional Metal Oxide Nanoparticles into Carbon Nanotube Fiber

Uniform fabrication and structural robustness of functional carbon nanotube (CNT) fibers are pivotal but challenging for developing integrated structural-functional materials. Herein, we developed a general in situ dynamic trawling strategy, utilizing a floating-catalyst-derived CNT sock as a trapper, to uniformly process diverse metal oxide (M_<i>x</i>O_<i>y</i>) nanoparticles into an interpenetrating CNT network, which affords support for nanoparticles and preserves their own structural characters. It is found that the synergy of interfacial capillary force and tension drives nonagglomerative capturing of M_<i>x</i>O_<i>y</i> nanoparticles within a network scaffold and their puckering/rolling into fibers. We demonstrate high uniformity and large-scale processing of functional CNT fibers involving 12 representative M_<i>x</i>O_<i>y</i> nanoparticles with an adjustable loading. Impressively, even at a high guest content of 50%, the customized fibers showcase a superb combination of mechanical strength, electrical conductivity, and thermal conductivity, which endows the fiber fabrics for different application fields with superior performance and durability in contrast to functional core-shell CNT fibers constructed by conventional processing techniques. Our manufacturing strategy offers a general, powerful, and effective pathway for architecting advanced structural-functional CNT fibers.