Change in Aggregate Shape of Heat Treated Carbon Nanoparticles

To better understand the fusion mechanism of heated carbon black, heat treatment is conducted for carbon black produced by benzene pyrolysis. The effects of （a） heating time, （b） heating temperature and （c） heating rate on the aggregate shape and mean primary particle diameter of the carbon black are investigated using TEM （transmission electron microscopy）. The mean primary particle diameter does not change significantly when carbon black is heat treated. For short heating times and low heating temperatures, the aggregate shapes become simple when compared with those of non-heated carbon black, and shapes become complex with an increase in the heating time. Also, for low heating rates, the aggregate shapes become significantly simple when compared with those of non-heated carbon black. The results of this study suggest that sintering between primary particles is promoted under relatively low heating temperatures, and Ostwald ripening among aggregates is promoted under relatively high heating temperatures.