Orientation of single-walled carbon nanotubes by uniaxial pressure

Abstract

This article presents a very simple process to align macroscopic quantities of single-wall carbon nanotubes (SWNT), the alignment being controlled by x-ray diffraction. A pellet of SWNT is obtained by pressing a raw nanotube powder up to a pressure of 10 kbars. A detailed study of the most characteristic lines in the diffraction pattern reveals that the tubes have their axis aligned in the plane of the pellet within an out-of-plane spread angle of $\text{∼4°.}$ We also show that the intense small-angle signal—which is observed in all SWNT diffraction diagrams—can be assigned to both the form factor of the isolated nanotubes in the sample and the form factor of the bundles with various size and shape.