Covalently Functionalized Metallic Single-Walled Carbon Nanotubes Studied Using Electrostatic Force Microscopy and Dielectric Force Microscopy

Contact less electrostatic force microscopy (EFM) and dielectric force microscopy (DFM) are demonstrated to be very powerful tools of characterizing the electronic properties of individual single-walled carbon nanotubes (SWCNTs). Taking the advantages of the tools, we confirm that the metallicity of metallic SWCNTs can be largely preserved upon dichlorocarbene functionalization ([2 + 1] cycloaddition) in comparison with the SWCNTs subject to the Prato reaction ([2 + 3] cycloaddition). This work demonstrates the distinct difference between sp(2) rehybridized and sp(3) rehybridized covalent configurations on their influences to electronic properties of metallic SWCNTs and supports the hypothesis that [2 + 1] cycloaddition could recover the sp(2) hybridization on the sidewall of metallic SWCNTs and preserve the intrinsic electronic properties of SWCNTs.