Chemical alignment of oxidatively shortened single-walled carbon nanotubes on silver surface

We propose here a simple technique for the assembly of oxidatively shortened single-walled carbon nanotubes (SWNTs) on silver surface. This technique is based on the spontaneous adsorption (self-assembly) of the -COOH groups at the open ends of carbon nanotubes onto silver surface. Raman spectroscopy, tapping mode atomic force microscopy (TM-AFM), and transmission electron microscopy (TEM) results have shown that the oxidatively shortened SWNTs assemblies have been formed on the silver surface, with the nanotubes perpendicular to the surface. Moreover, TEM studies also revealed that most of the SWNTs (ca. 80%) assembled on silver surface have a bundle size of 6.5 +/- 0.5 nm, possibly suggesting the selective adsorption of SWNTs on silver.