Preparation of peapods

Preparation of peapods

Single Walled Carbon Nanotubes (SWCNT) provide an empty space which is rather isolated from outside conditions. This space can be filled with different structures. The most studied structure inside SWCNT is the C₆₀ fullerene. The resulting material is called a C₆₀ peapod (C₆₀@SWCNT). The filling is performed by mixing of C₆₀ and SWCNT. The mixture is  subsequently evacuated   and  heated above the sublimation point of C₆₀ for several days. The filling factor (the percentage of filled tubes) is dependant on the diameter distribution of the SWCNT, since only tubes 1.34 nm in diameter has an optimum value. The tubes with larger diameters do not stabilize C₆₀ and thus the filling of such a tubes is much lower. The best samples can have up to the 90% filling.

It is possible to fill SWCNT with other fullerenes including metallofullerens and clusterfullerenes. The success of such a filling procedure is related again to the diameter distribution of the starting SWCNT. Furthermore the preparation conditions are often limited by the stability of inserted fullerene. We tested many experimental conditions to find optimum parameters for synthesis of several types of peapod. At the moment the following structures are available: C₆₀@SWCNT, C₇₀@SWCNT, C₇₈@SWCNT, La@C₈₂@SWCNT, Dy₃N@C₈₀@SWCNT.

Fig1 . Schematic picture of C₆₀@SWCNT

Contact

Prof. Lothar Dunsch