Effect of hole size on the incorporation of C60 molecules inside single-wall carbon nanohorns and their release

We created holes in single-wall carbon nanohorns (SWCNH) by oxidation (SWCNHox) and investigated how the hole size affected the incorporation of C-60 in SWCNHox and their release from it. The incorporation of C-60 inside SWCNHox first occurred when the holes were opened by oxidation at 475 degrees C. It was followed by a steep increase in the incorporation quantity with increasing oxidation temperature. The release rate of C-60 from inside SWCNHox was slower than that of C-60 crystallites located outside, and did not depend on the oxidation temperature (475-550 degrees C), indicating that the release rates were not influenced by the hole sizes. (C) 2008 Elsevier Ltd. All rights reserved.