Anchoring conductive polymeric monomers on single-walled carbon nanotubes: towards covalently linked nanocomposites

The functionalization of carbon nanotubes (CNTs) has long been a challenge due to the low reactivity of CNTs. Herein we present a novel approach to covalently functionalize CNTs directly on the carbon surface with three different monomers of conductive polymers. A covalently linked polymeric nanocomposite derived from polypyrrole was also obtained. Highly reactive single-walled carbon nanotube (SWCNT) salts were functionalized with the monomers: 3-bromothiophene, 3-acetylthiophene and 1-(2-bromoethyl)-1H-pyrrole. After the functionalization, a "grafted from" approach was used to polymerize the pyrrole-derived SWCNTs and obtain a covalently linked polymeric nanocomposite. All samples were characterized by X-ray photoelectron spectroscopy, thermogravimetric analysis, scanning electron microscopy, and infrared and Raman spectroscopy. Overall, the results evidence the efficiency of the covalent functionalization directly on the skeleton of the SWCNTs, followed by the polymerization and formation of a novel covalently linked nanocomposite. These materials can benefit future optimal applications such as supercapacitors and artificial muscles.