Fullerene

About: Fullerene is a research topic. Over the lifetime, 12723 publications have been published within this topic receiving 359173 citations.

Photoconductivity of fullerene-doped polymers

Abstract: PHOTOCONDUCTING materials are employed in many technological applications, such as photodetection and electrostatic imaging.1 We report here the preparation of photoconducting films of polyvinylcarbazole (PVK) doped with fullerenes (a mixture of C60 and C70). The performance of this material is comparable with some of the best photoconductors available commercially, such as thiapyrylium dye aggregates2. The quantum yield for primary charge separation and the initial ion-pair distance are calculated, within the framework of the Onsager model3,4, to be 0.9 and 19 A respectively. The wavelength dependence of photoconductivity is essentially determined by the absorption spectrum of the fullerenes, with the active range extending from about 280 to 680 nm. The isolation of other fullerenes and fullerene derivatives may lead to the development of a large number of fullerene-based polymeric photoconductors in the future.

Purification of single-wall carbon nanotubes by microfiltration

Abstract: A purification procedure for single-wall carbon nanotubes (SWNTs) prepared by pulsed laser ablation is discussed, which separates coexisting carbon nanospheres (CNS), metal nanoparticles, polyaromatic carbons, and fullerenes from the SWNT fraction. The process involves the suspension of CNS, metal nanoparticles, and SWNTs in an aqueous solution using a cationic surfactant and the subsequent trapping of SWNTs on a membrane filter. No oxidative treatment is required. Scanning/transmission electron microscopy and Raman scattering were used to evaluate the purification process and the vibrational features of SWNTs. Purity of SWNTs at the final stage sample is in excess of 90% by weight, and no evidence of impurity carbon phases was revealed in the Raman spectrum of the SWNT fraction.

C36, a new carbon solid

Abstract: Under appropriate non-equilibrium growth conditions, carbon atoms form relatively stable hollow clusters of well-defined mass number1, collectively known as fullerenes. The mass production, purification and condensation of such clusters into a molecular solid is generally essential to full experimental characterization: the initial discovery2 of C60, for example, had to await a bulk synthesis method3 six years later before detailed characterization of the molecule was possible. Gas-phase experiments1,4,5 have indicated the existence of a wide range of fullerene clusters, but beyond C60 only a few pure fullerene solids have been obtained6, most notably C70. Low-mass fullerenes are of particular interest because their high curvature and increased strain energy owing to adjacent pentagonal rings could lead to solids with unusual intermolecular bonding and electronic properties. Here we report the synthesis of the solid form of C36 by the arc-discharge method3. We have developed purification methods that separate C36 from amorphous carbon and other fullerenes, to yield saturated solutions, thin films and polycrystalline powders of the pure solid form. Solid-state NMR measurements suggest that the molecule has D6h symmetry, and electron-diffraction patterns are consistent with a tightly bound molecular solid with an intermolecular spacing of 6.68 A. We observe large increases in the electrical conductivity of the solid on doping with alkali metals.