LAUSR

Abstract Carbon nanotube (CNT) fibers are merged into a robust larger-diameter yarn by using an adhesion agent of polyethylenimine (PEI). As compared to poly(vinyl alcohol) and epoxy, PEI molecules can unite neighboring CNT fibers by constructing a strong inter-fiber adhesion, owing to their high mobility to soften the fiber surface. The merged yarn inherits fully the tensile strength and toughness from the single fiber, remains electrically conducting, and can be stably used up to 180 ° C even in O 2 . It also exhibits high mechanical performances under various application conditions, such as bending, pressing, twisting, and rubbing.