i Nanorope ~ nanoall - Nanotechnology Blog



A spiral or twisted carbon fiber shows various properties which a straight carbon fiber does not possess. The spiral or twisted carbon fiber has a large surface area compared with a straight carbon fiber having the same length of fiber, has a fine curved surface or angle as seen from any direction, has an electrical inductance, and has a mechanical spring function.
Nanorope structure
Carbon nanotubes can self-organize into "ropes," which consist of many (typically, 10-100) tubes running together along their length in contact with one another. Since the sides of the tubes are very smooth, carbon bonds of one tube can get relatively close to the next one and the electrons in one tube will influence the motion of some electrons in its neighbor to give rise to a short-range attractive van der Waals force between the tubes. This binding energy is approximately 0.5eV per nanometer of contact length and carbon bonds will be very difficult to separate. Such formed ropes can be far longer than any individual tube within them, but are virtually endless, branching off from one another, then joining others while individual tubes are typically about 100-2000 nm in length. In the nanoropes more than dozens of individual nanotubes are stacked together in a fairly regular pattern and looped up. These ropes are useful in providing very long electrically conductive pathways in nanotube films and composite materials.
This structure also lead to a cable or rope that has much better load transfer mechanism in tension, than a straight bundle would have. This is akin to the fact that twisted textile fibre or a steel wire is more stronger than a bundle of untwisted fibres.
The carbon nano-twist and carbon nano-rope has a structure having no space, that is, a structure having no hole in its central portion as seen from its longitudinal direction and is more stronger due to the fact that more than one carbon nano-fibers is twisted and intertwined.
Carbon nano-rope films can be fabricated on the Ni-catalysed Si substrate by microwave plasma-enhanced chemical vapor deposition employing a mixture of acetylene and hydrogen. These nano-ropes will be in the form of self-assembled, stranded of carbon nano-fibers aligned perpendicular to the substrate.
A carbon nano-fiber, particularly twisted carbon nano-fiber such as a carbon nano-coil, carbon nano-twist or carbon nano-rope is produced by means of a catalyst by CVD method using carbon-containing gas as a raw material and a catalyst comprising one or more components selected from the group consisting of Cr, Mn, Fe, Co, Ni and oxide thereof and one or more components selected from the group consisting of Cu, Al, Si, Ti, V, Nb, Mo, Hf, Ta, W and oxide thereof.
A nano-rope made of a single type of specially chosen molecule will be very strong. A cable or rope can be assembled with incredible tensile strength with correctly-aligned nanotubes. A nanotube rope of one centimeter diameter can support the weight of one human being and weighs just 10 milligrams per kilometer.It is lightweight and invisible and can be used to create a series of invisible ropes in architecture.
Nanotubes are very interesting objects for channeling research. A beam can be trapped in a single nanotube cylinder of 1 nm diameter or in a rope consisting of many nanotubes. Also particle beam of very small cross-section is just emerging as a beam instrument and is found useful in many accelerator applications including biological and medical ones. A typical nano-rope consisting of 100-1000 nanotubes would be a source that gives an emittance of the nano-beam of the order of 0.001p nm horizontally and vertically, factor of 10000 down from the figure potentially achievable with a traditional amorphous source.
Polypyrrole nanowires formed by polymerization of pyrrole on a DNA template self-assemble into rope-like structures. These ‘nanoropes’ may be quite smooth (diameters 5–30 nm) or may show frayed ends where individual strands are visible. Nanoropes are conductive and adhere more weakly to hydrophobic surfaces prepared by silanization of SiO2 than to the clean oxide; this effect can be used to aid the combing of the nanoropes across microelectrode devices for electrical characterization

0 Responses to “Nanorope”

Post a Comment

All Rights Reserved nanoall - Nanotechnology Blog