Multifunctionalization of carbon nanotube fibers with the aid of graphene wrapping

Abstract

Carbon nanotube (CNT) fibers are promising candidates for developing multifunctional textiles. The direct introduction of functional guests within or around CNT fibers meets problems due to the rough fiber surface and weak interfacial bindings. To improve the functionality and performance stability, we report a new method to modify the surface roughness and level of functionalization of CNT fibers, by wrapping graphene oxide (GO) or reduced graphene (RG) around them. Besides the functional groups on the graphene sheets, the introduction of a graphene layer also has smoothing and shield effects, resulting in higher tensile strength and improved and stabilized performance. The electrochemical and photocurrent applications were exploited by depositing polyaniline around GO-wrapped CNT fibers and TiO₂ around RG-wrapped fibers, with a capacitance up to 229.5 F cm⁻³ and a photocurrent density of 132 μA cm⁻², respectively. The present technique has the advantage that the mechanical and functional properties can be optimized by simply modifying the core CNT fiber via polymer infiltration during the fiber spinning.