Characterization of carbon nanotube webs and yarns with small angle X-ray scattering: Revealing the yarn twist and inter-nanotube interactions and alignment

The control of the carbon nanotube alignment remains a great challenge in order to enhance the mechanical and electrical properties of self-supporting nanotube yarns. In this paper the nanotube alignment within a series of self-supporting webs and yarns is for the first time deduced from the analysis of small angle X-ray scattering data. We propose a novel method to characterize the alignment of carbon nanotube yarns and demonstrate that the twist of the nanotubes can be very well matched to the full width at half maximum of the integrated azimuthal angle of the SAXS peak corresponding to the CNTs.