12/24/10

A short introduction on: Carbon nano tube and the reaction dynamics inside it-Part 1


Anant Babu Marahatta

Ph.D. Student in Chemistry
Tohoku University,Japan



This is the age of science and technology. In the world, many technological devices have been used and constructed which are the blessings of the science. In the field of science, nanotechnology plays crucial role for the innovation of several nano size devices from the nano materials either by modifying their properties or by using them directly.

Generally, nanotechnology is defined as the engineering of functional systems at the molecular scale. In recent years, properties and structures of nano size materials have attracted many people's attention. Their unique properties and small dimensionality give very promising future for various potential applications. Out of the several nano materials, the history of the newly discovered allotropic forms of carbon called “Fullerene” is the recent one. Significant progress has been made toward the understanding of the properties and structures of nano tubes.
FIG.1 [a] A hexagonal graphite sheet to create a zig-zag or armchair nanotube by rolling up along or y axis; [b] A graphite sheet with active –COOH groups; [c] An armchair SWNT with a diameter of 8.15 Å; [d] A hydrophilic SWNT with –COOH groups having an inner diameter of 8.40 Å.
Carbon nanotubes (CNTs) are carbon allotropes. Their name has been derived from their size, since the diameter of a nanotube is in the order of a few nanometers (approximately 50,000 times smaller than the width of a human hair), while they can be up to several millimeters in length. They are mainly of two types: single-walled nanotubes (SWNTs) and multi-walled nanotubes (MWNTs). A single-walled carbon nanotube is a one-atom thick sheet of graphite (called graphene) rolled up into a seamless cylinder with diameter on the order of a nanometer. This results in a nanostructure where the length-to-diameter ratio exceeds 10,000. SWNTs are a very important variety of CNT because they exhibit important electric properties that are not shared by MWNTs. The remarkable properties of SWNTs stem from the symmetry and unusual electronic structure of graphene.

The nature of the bonding of a nanotube is described by applied quantum chemistry, specifically, orbital hybridization. The chemical bonding of nanotubes are composed entirely of sp2 bonds, similar to those of graphite. This bonding structure provides the molecules with their extraordinary and unique strength and possibility of studying reactions dynamics into it. Such cylindrical carbon molecules have novel properties that make them potentially useful in many applications in nanotechnology, electronics, optics and other fields of materials science. They exhibit electrical properties, and are efficient conductors of heat. Due to strong sp2 bonding, carbon nanotubes are much less susceptible to electromigration (EM) problems that plague copper interconnects and can carry very high current density.

1 comment:

Dubai said...

Thanks for sharing your info. I really appreciate your efforts and I will be waiting for your further write ups thanks once again.
Vee Eee Technologies| Vee Eee Technologies|