pH-triggered release of materials from single-walled carbon nanotubes using dimethylamino-functionalized fullerenes as removable “corks”

Dimethylamino-functionalized fullerenes (pf-C60) have been used as removable “corks” at the openings of filled single-walled carbon nanotubes (SWCNTs). In a proof-of-principle study, SWCNTs have been filled with copper acetate or uranyl acetate, and these encapsulated materials then “corked” with pf-C60. The use of pf-C60 as “corks” allows the removal of the large amount of external acetate present after the filling step and a pH-triggered release of the encapsulated materials. A pH-sensitive discharge of the cargo would be of interest, for instance, in drug delivery systems.