No abstract

Strong luminescence emissions over a broad wavelength region were detected from well-dispersed carbon nanotubes in most functionalized samples, even with excitation wavelengths into the near-IR. Apparently, the better dispersion and functionalization of the nanotubes resulted in more intense luminescence emissions. These emissions may logically be attributed to the trapping of excitation energy by defect sites in the nanotube structure, which are passivated upon the appropriate functionalization of the nanotubes. Better functionalization improves not only the nanotube dispersion (thus diminishing the quenching due to intertube interactions) but also the surface passivation to make the energy trapping sites more emissive, leading to stronger luminescence emissions. Because of such high sensitivity, the visible luminescence emissions may prove valuable in the evaluation of dispersion in functionalized carbon nanotube samples and related nanocomposite materials.

No abstract

Single‐walled carbon nanotubes have been functionalized with derivatized porphyrins (see Figure). The photoexcited state properties of the nanotube‐tethered porphyrin moieties are investigated via steady‐state and time‐resolved fluorescence methods. Intramolecular energy‐transfer quenching of porphyrin fluorescence by the tethered nanotube occurs in the sample with a longer tether, but no fluorescence quenching is observed in the sample with a shorter tether.