A new application of synchrotron radiation to carbon nanotubes - shape control and purification

Irradiation with synchrotron radiation (SR) was applied to multi-wall carbon nanotubes (MWCNTs). We observed the shape exchange, visualization, and purification of the MWCNTs with various SR ring currents and irradiation times. At a relatively low (127 mA) ring current and a long irradiation time (4 min), the MWCNTs were purified by evaporation of graphite impurities. At a relatively high ring current (210 mA) and a long irradiation time (65 sec), the MWCNTs were decomposed. At a relatively high ring current (300 mA) and a short irradiation time (10 sec), the shape of the MWCNTs changed to carbon nano-wall-like construction keeping its graphite networks.