Macroscopic alignment of single-walled carbon nanotubes (SWNTs)

Abstract

We report the progress of alignment and organization of single-walled carbon nanotubes (SWNTs). Using single strands of DNA, as-received bundled SWNTs are effectively dispersed in a water-based medium under light. This high level of dispersity was evident from the resulting stable, homogeneous solutions provided by the helical wrapping of the DNA to the SWNT. We have also demonstrated that these DNA-coated carbon nanotubes can be orientated with non-contact methods. Specifically, we utilize a modified inkjet printer as a tool for direct printing and alignment of DNA-wrapped carbon nanotubes on a treated mica substrate. In addition, we see evidence of orientation due to centrifugal forces in the radial direction of the spin coater. These layers of oriented tubes are characterized by both scanning electron microscopy (SEM) and atomic force microscopy (AFM). The inkjet fabrication process is a promising method for increasing the directional strength of high strength, carbon nanotube materials.