多壁碳纳米管的纯化及修饰

Purification and Preliminary Modification of Multi-walled Carbon Nanotubes

通过以碱(NaOH)为分散剂进行预处理增大化学反应活性,再以高温加热除去无定型炭等非高度石墨化物质,最后运用混酸(3∶1浓硫酸和浓硝酸)进一步去除无定型炭及碳纳米管制备过程中的金属催化剂和金属氧化物,并在纯化的同时引入羧基和羟基等官能团,使修饰后的碳纳米管稳定性、分散性大大加强。

A method of purifying carbon nanotubes is introduced. Firstly, alkali is used as disseminating agent to pre-treat the tentative product to make it form smaller granules with higher specific surface area and reactivity. Secondly, the amorphous carbon is eliminated with high temperature. In the end, the initial product is oxidized with a mixture of HzSO4 （98%）/HNO3 （68%） （3 ： 1 v/v）. Through these series of steps, the raw material of MWNTs are purified and such functional groups as carboxyl and hydroxyl are introduced which greatly improved the dispersion degree and stability of MWNTs.