Investigation of nanotube functionalization techniques: EB processing and characterization

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 therefore requires the implementation of a method of functionalization in order to interact with solvents or monomers. In this work, we have developed a novel method of nanotube modification in which dry multiwalled carbon nanotubes are irradiated with a high-energy electron beam (EB) in air environment. Raman spectroscopy was used to characterize the influence of EB irradiation on the graphitic structure. Spectra show increased deformation to the graphitic structure, as well as increased strain on carbon-carbon bonds, with increasing EB dose. TEM and Thermogravimetric analysis confirm that minimal deformation occurred with high EB dose, and nanotubes remained intact for doses up to 1000 kGy. Analysis with X-Ray Photoelectron Spectroscopy offers insight into the chemical constituents and functionalities on EB-irradiated nanotubes.