| Abstract
| - Water-based FePt nanoparticles (NPs) have been used to disperse acid-treated HiPCO single-walled carbonnanotubes (SWNTs) in TMAOH solution under mild experimental conditions. The result shows that seriouslyaggregated SWNTs with bundle sizes from 20 to ∼30 nm can be exfoliated into individually dispersed tubesin water while their intrinsic chemical properties and long lengths are kept intact. A novel nanoball-penetratingmethod is proposed, and the dispersion and exfoliation mechanism is discussed to explain the debundlingresults. Electrostatic interaction between (CH3)4N+ and carboxyl groups on SWNTs decreasing the van derWaals force of the bundles, deep penetration of FePt NPs into the gaps of SWNT ropes, and repulsive interactionbetween negatively charged SWNTs and FePt NPs all contribute to the final efficient exfoliation. More than50% of SWNTs can be debundled into individually dispersed nanotubes under optimum conditions. Ramanscattering spectroscopy used to characterize the properties of SWNTs proved that the exfoliation process isnoncovalent by nature. The dispersion and debundled process can be easily scaled up at low cost, and thiswill allow for the investigation of various nanotube-based nanocomposites and will pave the way for variedapplications of SWNTs on a large scale.
|
