C60 Nanotubes Research Articles

New Fullerene-Based Stationary Phases for Gas Chromatography

Regularities were revealed for the retention of different classes of organic compounds on stationary phases based on C60 and carbon nanotubes and on phases of mixed composition (C60 and dibenzo-24-crown-8, C60 and dibenzo-30-crown-10, and C60 and β-cyclodextrin) in gas chromatography. A synergistic effect was observed for the stationary phases of mixed composition. Quantitative estimation of the dispersion potential demonstrated that the C60-based stationary phase differs significantly from hydrocarbon adsorbents and more closely resembles nonpolar liquid stationary phases. Under the conditions of solid-phase microextraction, an adsorbing element based on fullerene C60 can be used for the preconcentration of aromatic hydrocarbons.

Effects of carbon nanosolids on the electro-optical properties of a twisted nematic liquid-crystal host

We present results of the electro-optical effect in 90° twisted nematic cells of pristine and doped liquid crystals under an applied dc voltage. The doped cells were fabricated with a minute addition of either buckminsterfullerene C60 or multiwalled carbon nanotubes (CNTs). Investigated were the switching behaviors as well as the hystereses and time evolutions of both the optical transmittance and electrical capacitance of the display samples. It is shown that doping with nanotubes can effectively reduce the dc driving voltage and improve the switching behavior.

Hydrogen chemisorption on sp 2 -bonded carbon: Influence of the local curvature and local electronic effects

We report on the interaction of hydrogen with sp2-bonded carbon which has been investigated on graphite (0001), single-walled carbon nanotubes and C60 multilayer films. These substrates have been chosen to represent a large range of curvature in the carbon network. The photoelectron spectroscopy study of the samples treated with atomic hydrogen and low-energy hydrogen ions reveals that hydrogen is chemisorbed on the basal plane of the sp2-bonded carbon networks, as evidenced by the lowered emission from π-derived states and a lowering of the electron work function of up to 1.3 eV. The hydrogen adsorption energy barrier is found to strongly depend on the local curvature of the carbon network whereby the barrier is lowered with increasing curvatures. Whereas in the case of C60 and single-walled carbon nanotubes, hydrogen chemisorption can be achieved by exposure to atomic hydrogen, the chemisorption on graphite (0001) requires hydrogen ions of low kinetic energy (∼1 eV). Furthermore, the adsorption energy barrier is found to increase with hydrogen coverage. The scanning tunnelling microscopy study of individual adsorption sites on the graphite (0001) surface reveals long-ranged (∼5 nm) electronic effects observed as a (sqrt(3)×sqrt(3))R30° superstructure in the local density of states. It is shown that this superstructure is due to the scattering of delocalized electron wavefunctions at the point defects. The resulting standing waves induce a redistribution of the local density of states which is directly related to the point-like Fermi surface of graphite.

Imaging as-grown [60]fullerene nanotubes by template technique.

In this contribution we have developed a useful and experimentally easy way to use C60 powder to directly fabricate C60 nanotubes with a mondisperse size distribution and uniform orientation. The structure of C60 nanotubes was confirmed by SEM, TEM, and FT-IR.

Synthesis of All-carbon Chains and Nanoparticles by Chemical Transformation of Halogenated Hydrocarbons at Low Temperatures

The paper reviews synthetic procedures towards carbonaceous materials via chemical dehalogenation or dehydrohalogenation of halogenated hydrocarbons, which take place at mild temperatures and pressures. Special attention is being paid to a preparation of unusual carbon structures, viz. sp-bonded all-carbon chains (carbyne-like materials), fullerenes, and carbon nanotubes. This article upgrades previous reviews on this subject, published in 1997. Among the most interesting recent outputs, we may quote the preparation of fullerene C60 and multiwalled carbon nanotubes by simple chemical reactions occurring at ambient conditions.