Synthesis of polystyrene brush on multiwalled carbon nanotubes treated with KMnO4 in the presence of a phase-transfer catalyst

Multiwalled carbon nanotubes (MWNTs) were effectively functionalized with KMnO4 in the presence of a phase-transfer catalyst at room temperature. The hydroxyl functionalized MWNTs were reacted with a vinyl-group carrying silane-coupling agent and the terminal vinyl groups were used to fabricate polystyrene (PS) brushes by solution polymerization. Finally, PS-encapsulated MWNTs were obtained. The synthesis results were verified from FT-Raman, thermal gravimetric analysis, energy dispersive X-ray analysis, and transmission electron microscope. PS-encapsulated MWNTs had much improved dispersion stability in hydrophobic medium, toluene since grafted hydrophobic PS interacts with media and has improved compatibility. This functionalization technique would provide a facile route to prepare various polymer brushes on the surface of MWNTs to improve the dispersion of MWNTs for potential applications. (c) 2007 Wiley Periodicals, Inc.