The opening and filling of single walled carbon nanotubes (SWTs)

Single walled nanotubes (SWTs) can be selectively opened and filled using wet chemistry techniques; treatment of the carbon nanomaterials with concentrated HCl apparently leads to the selective opening of the SWTs at their tips; foreign materials can then be deposited inside the resulting cavities in a similar fashion to multi-walled carbon nanotubes (MWTs); the filling of SWTs with small spherical crystals and, additionally, preferentially orientated and elongated single crystals of Ru metal is described; the selective opening of SWTs was inferred from these observations.