Rapid, one-pot synthesis of highly-soluble carbon nanotubes functionalized by L-arginine

Functionalization of carbon nanotubes (CNTs) is a necessary step to exploit their valuable properties. Due to having several steps and especially acid treatment, most of current methods of functionalization result in irrecoverable defects on CNTs structure. Here, multiwalled carbon nanotubes (MWCNTs) were functionalized with L-arginine in a simple, one-pot and rapid microwave-assisted technique without any acid treatment step. The CNT functionalities were analyzed with infrared spectroscopy, thermogravimetric analysis, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy. The results confirmed the covalent functionalization of L-arginine with very low defects on CNTs. Also it is found that increase of input powers of microwave in the range 500–900 W, monotonically increase the degree of functionalization. The maximum dispersibility of MWCNT was found ～1.03 mg/mL corresponding to 900 W irradiation. Accounting considerable low treatment time, the method may be applied for large-scale solubilization of MWCNTs in an industrial scale.