the electric quadrupole, hexadecapole moments, energy (kjmol -1) for some armchair polyhex carbon nanotubes tuvc6[2p,q] are performed by beck-lee-yang-parr [b3lyp] on 3-21g basis set using the standard procedure indices gaussian 98, then the padmakar-ivan (pi) index of tuvc6[2p,q] nanotubes in the terms of their circumference (2p) and lengh (q) is calculated and the relationships between the pa...

Carbon composite nanotubes are the harder than the diamond and composed by carbon. So we can identify the carbon-nanotube-based composite materials by polarized Raman spectroscopy This technique may be used to identify carbon nanotubes , access their dispersion in polymers, evaluate nanotube /matrix interactions and detect polymer phase transitions. The Raman spectra of nanotubes can also be us...

Single walled carbon nanotube shows excellent chemical and physical properties and it has been extensively explored for novel applications. It has been shown that single walled carbon nanotube can be used to improve sensitivity of sensors such as bio sensors, gas sensors and mechanicals sensor by its unique properties. As a mechanical sensor, a mechanical force deforms the single walled carbon ...

Carbon nanotubes (CNTs) are allotropes of carbon with a cylindrical nanostructure. Nanotubes have been synthesized with length-to-diameter ratio of up to 132,000,000 : 1, which is significantly greater than any other material. These cylindrical carbon molecules have novel properties which make them potentially useful in many applications in nanotechnology, electronics, optics, and other fields ...

To the Editor — In their survey describing the promises and challenges of carbon nanotubes in imaging and therapeutics, Kostarelos and colleagues1 state that “...chemically functionalized [carbon] nanotubes have been shown by many groups to be more biocompatible (no immune or acute inflammatory responses) than pristine nanotubes.” We point out below in vitro and in vivo studies that show surfac...

Carboxylic functionalization (-COOH groups) of carbon nanotubes is known to improve their dispersion properties and increase the electrical conductivity of carbon-nanotube-polymer nanocomposites. We have studied experimentally the effects of this type of functionalization on the thermal conductivity of the nanocomposites. It was found that while even small quantities of carbon nanotubes (~1 wt ...

Strain sensing characteristic of carbon nanotubes has been established in the past at nanoscale. In this study, it is shown that the carbon nanotube film sensors, made up of randomly oriented carbon nanotubes, can be used as strain sensors at macro level. A nearly linear trend between the change in voltage, measured using a movable four point probe, and strains, measured using conventional elec...

the effects of confinement in carbon nanotubes on fischer-tropsch (ft) activity, selectivity and lifetime of carbon nanotubes (cnts) supported iron catalysts are reported. a method was developed to control the position of the catalytic sites on either inner or outer surface of carbon nanotubes. tem analyses revealed that more than 80% of iron oxide particles can be controlled to be positioned a...

The properties of carbon nanotubes can be dramatically altered by the presence of defects. In this work we address the properties of two different kinds of defective nanotubes: junctions of achiral tubes with topological defects and partially unzipped carbon nanotubes. In particular, we begin by focussing on the interface states in carbon nanotube junctions between achiral tubes. We show that t...

Using concepts of hierarchical multi-scale modeling, we report development of a mesoscopic model for single wall carbon nanotubes with parameters completely derived from full atomistic simulations. The parameters in the mesoscopic model are fit to reproduce elastic, fracture and adhesion properties of carbon nanotubes, in this article demonstrated for (5,5) carbon nanotubes. The mesoscale model...