Photoluminescence from carbon nanotubes

We observed yellow colored light emission bands from multiwalled carbon nanotubes in photo-luminescence (PL) experiments. The light emission band features indicate that the PL bands are associated with the electronic properties inherent to the carbon nanotube (CNT) structures.

Observation of the resonant Raman behavior of individual single-walled carbon nanotubes

The different resonant Raman scattering process of single-walled carbon nanotubes (SWNTs) has been found between the Stokes and anti-Stokes sides of the radial breathing modes (RBMs), and this provides strong evidence that Raman spectra of some special diametric SWNTs are in resonance with their electronic transitions between the singularities in the one-dimensional electronic density of states in the valence and conduction bands, and other SWNTs axe beyond the resonant condition. Because of the coexistence of resonant and non-resonant Raman scattering processes for different diametric SWNTs, the relative intensity of each RBM does not reflect the proportion of a particular SWNT.

A new potential radiosensitizer- multi-walled carbon nanotubes modified by ammonium persulfate

Here we prepare carbon nanotubes modified with ammonium persulfate, very short carbon nanotubes with 50-100 nanometer length was obtained, and the higher P potential of 52 mV was detected, these supporting the successful modification. HeLa cells were irradiated with P rays via adding or absent above functionalized carbon nanotubes (f- WCNTs) into cell culture medium with different concentration and radiation dosage. Confocal microscopy images and fluorescence-labeled DNA detection verified the successfully pure multi-walled carbon nanotubes (p-WCNTs) and f-WCNTs penetrated into cells. Compared with pure radiation, by MTT test, f-WCNTs induced cell death markedly with about 8.7 times higher than former one under little dose of radiation; meanwhile, no obvious toxicity was observed both in p-WCNTs and f-WCNTs without of radiation exposure. We hypothesized that large amount of hydroxyl and carbonyl organs on the surface of very short f-WCNTs changed into free radicals result from radiations led cell damage. These implied that f-WCNTs could be regarded as a new radiosensitizer.

Preparation and characterization of CdS nanotubes and nanowires by electrochemical synthesis in ion-track templates

CdS nanotubes and nanowires have been synthesized with controlled dimensions by means of template-electrodeposition method in etched ion-track membranes. The diameters of nanotubes and nanowires are between 20 and I 10 nm, and the lengths are up to tens of micrometers. X-ray diffraction (XRD) and selected area electron diffraction (SAED) pattern investigations demonstrate that CdS nanotubes and nanowires are polycrystalline in nature. The UV-vis absorption spectra of CdS nanotubes and nanowires embedded in polycarbonate (PC) membranes show that the absorption edges of PC films shift towards the shorter wavelength, with decreasing diameters of the deposited nanostructures. The results indicate that nanowires are formed from nanotubes by nanotube-stuffing-growth mechanism.