Functionalization of Carbon Nanotubes by Chemical Method with Minimal Structural Damage

In this study, carbon nanotubes with high purity were functionalized by chemical method using sulfuric acid, nitric acid and hydrochloric acid. In order to investigate the morphology of the pristine and functionalized nanotubes, scanning and transmission electron microscopy was used. Also to investigate the functional groups formed on the surface of the nanotubes, Raman spectroscopy and infrared spectroscopy methods were used. According to the results suitable acid mixtures for the functionalization of carbon nanotubes were containing sulfuric acid, nitric acid and hydrochloric acid with volume of 60, 20 and 20 ml, at concentrations of 12, 12 and 10 molar respectively in the presence of 0.1 g of carbon nanotubes. The temperature of 150 °C and time of 4 h are the optimum parameters for created the functional groups on the surface of nanotubes. According to the results carbon nanotubes functionalized with minimal structural damage weregenerated. The results of infrared spectroscopy confirmed the presence of carboxylic and hydroxyl functional groups on the surface of the nanotubes.