Opening and reversible filling of single-walled carbon nanotubes with various materials

Single-walled carbon nanotubes have been advocated as perfect candidates for the sustainable miniaturisation of electronic and mechanical nanoscale devices. The encapsulation of selected compounds within the inner hollow cavity of SWNTs allows controlled preparation of nano-meter size "nanowires" and "nanocables" with purpose-tailored physical properties. Therefore is crucial to have control of opening and closing their tips. In a previous study we showed that molten metal hydroxide [MOH (M==Cs, Na)] is filled into the carbon nanotubes and can be easily washed out with water leaving opened nanotubes. Following this approach we have explored the use of milder ways to open SWNTs that can be easily scalable for the production of large amount of opened SWNTs. The opened tubes have then successfully been filled in solution with various inorganic and organic materials.