Tunable grafting of functional polymers onto carbon nanotubes using diazonium chemistry in aqueous media

In this work, we present an efficient grafting of functional polymers onto multi-walled carbon nanotubes using a simple and versatile chemical process carried out in open air and in aqueous media. The method involves in situ reduction of substituted (-COOH, -NH2, -F center dot center dot center dot)aryl diazonium salts which yields poly (phenylene)-like coatings covalently grafted on the nanotube surface. Tuning the concentration of in situ generated diazonium was found to be an efficient way to control the total amount of grafted polymer. Functionalized nanotube samples were studied by complementary techniques such as electron microscopy, thermogravimetric analysis and X-ray photoelectron spectroscopy.