Communication: The solubility properties of single-walled carbon nanotubes
(SWNTs) and the factors that control the dissolution of these materials hav
e been investigated in detail. The authors report a number of strategies th
at lead to soluble SWNTs, in particular the covalent attachment of long alk
yl chains to the carboxylic acid-terminated SWNTs shown in the Figure (prod
uced by the purification process) via formation of amides and by formation
of zwitterions by an acid-base reaction.