Functionalization of carbon nanotubes via nitrogen glow discharge.

We have exposed single-wall carbon nanotubes (SWCNTs) to microwave-generated N2 plasma with the aim to functionalize the nanotubes. The results strongly depend on the distance between the discharge source and the sample, since nitrogen atoms generated can be lost due to recombination. No functionalization was observed when this distance was 7.0 cm. At intermediate distances (2.5 cm), the incorporation of nitrogen and oxygen onto the SWCNT was observed, while, at short distances (1 cm), products containing CN were also observed.