Fully recyclable carbon nanotube fibers

Challenges and limitations in the recycling of metals, polymers, and carbon fibers have been a major concern to climate change and material circularity. With demonstrated property overlaps and increasingly efficient production, carbon nanotube (CNT) fibers can become a sustainable replacement to hard-to-decarbonize incumbent industrial materials. Here, we show that solution-spun CNT fibers can be fully and easily recycled without loss of properties and irrespective of their constituent CNTs. Continuous segments of virgin, single-source CNT fibers made from different CNTs were mixed together in solution and reprocessed into a recycled, mixed-source CNT fiber with the same morphology, structure, alignment, and properties of the virgin, mixed-source CNT fiber made by directly mixing the raw CNTs. Following the ongoing improvements in CNT synthesis and CNT fiber manufacturing, recyclability further positions CNT fibers as a promising alternative to realize the transition to a greener future with a circular economy.