HRTEM and EELS investigation of functionalized carbon nanotubes

We have successfully resolved and visualized the structure of some chemically functionalized carbon nanotubes (CNTs) using high-resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS). To represent the chemically modified CNT, we selected three systems. The first system is oxidized and surface thiolated MWCNT, the second system is Dy₃N@C₈₀ peapods prepared by depositing trimetal nitride fullerenes into SWCNT. The formed structure is the Dy₃N@C₈₀@SWCNT. The third system is the conventional C₆₀@SWCNT fullerene peapods, fluorinated by xenon difluoride (XeF₂) up to 18% of F. We achieved detection of very low amount (0.6%) of sulfur and proved covalent bonding onto MWCNT surface. We present EELS imaging of the separated metal clusters inside endohedral metallofullerene peapod bundles and in the fluorinated C₆₀ peapods we show homogeneous fluorination across the whole surface.