Electron beam modification and functionalization of MWNT for covalent dispersion into polymeric systems

The development of nanotube-based polymer composites with improved mechanical properties and electrical conductivity requires the covalent dispersion of carbon nanotubes to utilize their stress transfer capabilities. Covalent dispersion of nanotubes therefore requires the functionalization of their surface to interact with solvents or monomers. In this work, we have developed a novel method of nanotube surface modification in which dry MWNT are irradiated with a high-energy electron beam (EB) in ambient air environment. Raman spectroscopy was performed to characterize the influence of EB irradiation on nanotubes, namely, variance of the disorder, or D band (∼1360 cm−1) with respect to the graphitic, or G, band (∼1580 cm−1). Raman spectra show increased deformation to the graphitic structure, as well as increased strain on the carbon–carbon bonds, weakening the nanotube. Transmission electron microscopy (TEM) confirms that nanotubes remain intact despite high EB dose. In addition, minimal surface deformation and length reduction occurred on irradiated MWNT.