Reversible filling of single walled carbon nanotubes opened by alkali hydroxides

摘要

Single wall carbon nanotubes (C-SWNTs) were first filled with ruthenium chloride 1 and fullerenes 2, It was then found that C-SWNTs could be readily filled using molten metal halides at the high temperatures (500-900 deg C) required to obtain the molten state 3,4. More recently we described a simple method to form empty, open C-SWNTs. This was by heating with molten caesium hydroxide at 300 deg C and then removal of the CsOH which had entered and filled the C-SWNTs by washing with water at room temperature 5. This was the first time that it had been possible to wash out the filling from filled C-SWNTs prepared by the molten media method. For example C-SWNTs filled with potassium iodide using the molten salt could be re-fluxed in boiling water for over a week without loss of the potassium iodide from the interior of the C-SWNTs 6, We envisage there will be many applications for C-SWNTs filled with materials, including chemical systems which are thermally unstable above ambient temperatures. Therefore we have studied the opening of C-SWNTs using metal hydroxides and their filling behaviour.