Carbon nanotubes
Structure
1D tubular structure with rolled up layers of graphene sheets forms the CNTs.
They are generally made of sidewall and two end caps: the sidewall is made of
benzene ring while each end caps are composed of hemi fullerene molecule.
Even though, the actual discoverers of this nanorolled carbon structures were
two Russian scientists, Radushkevich and Lukyanovich in 1952, who published
a paper with transmission electron micrograph showing continuous inner
cavities with carbon filaments. However, this concentric cylindrical allotropic
structure of carbon became one of the major topics in nanomaterials research
through a rediscovery by the Japanese scientist Iijima.
Types of CNTs
Depending on the various fabrication technologies there arise various types of
CNTs: Single walled CNTs (SWCNTs), Multi walled CNTs (MWCNTs) and
Double walled CNTs (DWCNTs). Each type is unique by their structure,
physical and chemical properties thereby paving a way for numerous
applications in the field of nanotechnology. The chemical bonding of CNTs is
based upon the sp2orbital bond, making them the strongest and hardest material
documented in terms of tensile strength and elastic modulus. Depending on the
chirality of the tubes the electrical properties can vary from being either metallic
or semiconducting. The morphology of CNTs differs depending on the exact
process conditions and preparation methods. All these bonding and synthetic
variations, together with their nanometer scale diameter and high aspect ratio
makes CNTs exhibit excellent mechanical, electrical and magnetic properties
thus making them an ideal reinforcing agent for high strength polymer
composites.
Structure
1D tubular structure with rolled up layers of graphene sheets forms the CNTs.
They are generally made of sidewall and two end caps: the sidewall is made of
benzene ring while each end caps are composed of hemi fullerene molecule.
Even though, the actual discoverers of this nanorolled carbon structures were
two Russian scientists, Radushkevich and Lukyanovich in 1952, who published
a paper with transmission electron micrograph showing continuous inner
cavities with carbon filaments. However, this concentric cylindrical allotropic
structure of carbon became one of the major topics in nanomaterials research
through a rediscovery by the Japanese scientist Iijima.
Types of CNTs
Depending on the various fabrication technologies there arise various types of
CNTs: Single walled CNTs (SWCNTs), Multi walled CNTs (MWCNTs) and
Double walled CNTs (DWCNTs). Each type is unique by their structure,
physical and chemical properties thereby paving a way for numerous
applications in the field of nanotechnology. The chemical bonding of CNTs is
based upon the sp2orbital bond, making them the strongest and hardest material
documented in terms of tensile strength and elastic modulus. Depending on the
chirality of the tubes the electrical properties can vary from being either metallic
or semiconducting. The morphology of CNTs differs depending on the exact
process conditions and preparation methods. All these bonding and synthetic
variations, together with their nanometer scale diameter and high aspect ratio
makes CNTs exhibit excellent mechanical, electrical and magnetic properties
thus making them an ideal reinforcing agent for high strength polymer
composites.
