Effect of Chemical Functionalization on the Raman and Optical Spectra of Carbon Nanotubes Igor Vasiliev, Department of Physics, New Mexico State University, Las Cruces, NM 88003 Our research focuses on predicting the structures, vibrational modes, and optical characteristics of covalently functionalized carbon nanotubes and nanotube-based nanocomposite materials. Properties of metal-nanotube heterostructures: Metal-nanotube heterostructures have attracted significant interest due to their potential appli-cation in catalysis, fuel cell technology and hyd-rogen storage. To understand the mechanism of metal-nanotube interaction, we have studied the adsorption of potassium atoms on graphene and nanotubes. Our study showed the impor-tance of long-range ionic forces in this system. Functionalization of carbon nanotubes by carboxyl groups: Covalently functionalized carbon nanotubes can be used as reinforcing agents in polymer and epoxy com-posite materials. To study the mechanism of covalent sidewall functionalization of carbon nanotubes, we have calculated the structures, bonding energies, and dissocia-tion energy barriers for a carboxyl group attached to the surface of a single-walled nanotube. The formation of the covalent bond between the carboxyl group and the nanotube sidewall was studied in three specific cases: (a) a defect-free nanotube, (b) a nanotube containing a Stone-Wales defect, and (c) a nanotube containing a vacancy. Our study showed an important role of surface defects in covalent sidewall functionalization of carbon nanotubes.