MODIFICATION OF CARBOXYLATED MULTI-WALLED CARBON NANOTUBES VIA ESTERIFACTION BY A WATER-SOLUBLE DYE

All reagents and solvents were obtained from Merck Chemical Inc. and MWNT–COOH (90% purity, 1–2 nm) were purchased and used as received. The FT-IRspectrum was recorded using KBr tablets on a Nexus 870 FT-IR spectrometer (Thermo Nicolet, Madison, WI), UV-visible spectra was recorded on a UVVisiblespectrometer (GBC Cintra 20, Victoria, Australia), 1HNMR spectrum was recorded on Bruker DRX-300 Avance spectrometer at solution in CDCl3using TMS as internal standard. SEM was used to study the morphology of the MWNTs. SEM measurement was carried out on the XL30 electron microscope (Philips, Amsterdam, Netherlands).