CNTs generated by underwater arc discharge are broadly classified into two types according to diameter. Multi-walled nanotubes (hereafter, MWNTs) between 20 nm and 50 nm in diameter, which is the normal diameter range of CNTs ; and large carbon nanotubes (hereafter, LCNTs) with relatively large diameters of between 100 nm and 300 nm. These two types are generated simultaneously.
Assuming that the difference in diameter of these products is due to arc discharge intensity and water temperature, this study conducted underwater arc discharge under low and high temperature conditions and compared the diameter and generation ratio of the products.
Conducting underwater arc discharge in a low water temperature environment between 20°C and 50°C and in a high water temperature environment between 80°C and 100°C, and comparing the diameter and generation ratio of CNTs generated in each temperature range confirmed that, at both voltage/current values, many LCNTs were generated under the high temperature conditions and many MWNTs were generated under the low temperature conditions.
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