Fullerenes as precursors for nanocapsule formation

Abstract

We have shown that Ni metal particles when melted in the presence of C60 form graphitic layers around themselves with the Ni remaining as pure metal and without any evidence of carbide formation. We have successfully encapsulated particles over several orders of magnitude of size from ∼10 nm to several microns. The process has been observed taking place in real time using transmission electron microscopy (TEM). The process was not observed when graphite powder was used instead of C60 powder and the Ni similarly heated to melting point, using the electron beam. Heating a mixture of Ni and C60 powders together in a conventional manner also produced encapsulated Ni particles. This suggests that the encapsulation method is thermal in nature although the electron beam does offer the ability to control the process for individual particles. Further research has shown that the encapsulation process can also occur at temperatures as low as 800° C by a catalytic route. We have extended the work of heating a metal in the presence of fullerenes and have effectively encapsulated other metals such as Fe, Co, Ho, Cu and Au.