Suspension of carbon nanotubes in natural humic acid water
The widespread use of carbon nanotubes (CNTs) may cause them to be released into the environment.Their interaction with natural organic matter enhances their dispersion in water, leading to a severe environmental threat.In this study, the effect of dissolved humic acid (HA) on the dispersion of graphitized or hydroxylated CNTs in water was investigated by repeated dispersion of both CNTs in HA water with a concentration of 100 mg/L for 19 times.Results showed that the cumulative adsorption amounts of HA on the graphitized CNTs increased and leveled off, but those on the hydroxylated ones increased continually with the number of dispersions.The amounts of graphitized CNTs suspended in HA water were always lower than those of the hydroxylated ones, which reached a maximum after 4 of 5 dispersions.TEM images showed that hydroxylated CNTs were shorter than the graphitized ones and the suspended CNTs were shorter than the un-suspended ones for both types of CNTs, indicating that CNTs with more defects are easily suspended.
Carbon nanotubesClassified suspensionTransmission electron microscopyThermogravimetric analysis
国家科技期刊平台
NSTL
万方数据
维普
