What are carbon nanotubes
CNT: Rolling-up a graphene sheet to form a tube
of a CNT
DID YOU KNOW?
Carbon nanotubes, composed of interlocking carbon
atoms, are 1000x thinner than an average human hair – but can
be 200x stronger than steel.
Radushkevich and Lukyanovich publish a paper in the Soviet Journal of
Physical Chemistry showing hollow graphitic carbon fibers that are 50
nanometers in diameter.
John Abrahamson presented evidence of carbon nanotubes at the 14th
Biennial Conference of Carbon at Pennsylvania State University.
A group of Soviet scientists published the results of chemical and structural
characterization of carbon nanoparticles produced by a thermocatalytical
disproportionation of carbon monoxide.
Nanotubes discovered in the soot of arc discharge at NEC, by Japanese
researcher Sumio Iijima.
Types of CNTs
Single Wall CNT (SWCNT)
Multiple Wall CNT (MWCNT)
Can be metallic or semiconducting depending on their geometry.
Diameter :- 1 nanometer
Band gap :- 0-2ev
A one atom thick layer of graphene
into seamless cylinder .
Their electrical conductivity can
show metallic or semiconducting
A scanning tunnelling microscopy image of SWNT
Multi-walled nanotubes (MWNT) consist
of multiple rolled layers (concentric tubes)
Interlayer distance :- 3.4 Å
To describe structure of MWNT there are
1. Russian doll model
2. Parchment model
Under some conditions, nanotubes can cross membrane barriers, which
suggests that if raw materials reach the organs they can induce harmful effects
such as inflammatory and fibrotic reactions.
As with any material, the existence of a crystallographic defect affects the
material properties. Defects can occur in the form of atomic vacancies.
• Field emission in Displays
• Application in electrodes, capacitors
• Used in transistors
• Lithium batteries
• Hydrogen storage
• Cancer treatment
• DNA sequencing
Fig : I-POD NANO
Fig: TRANSFORMATION OF TRANSISTORS FROM
HUGE SIZE TO NANO-CIRCUITS
Fig: Intel’s 32nm Nehalem chip
Fig: Paper battery
• Difficult control of CNT
• Improve resistivity of transparent SWNT films so that they are better than
equally transparent, optimally doped ITO coatings.
• Further price reductions of SWNT needed
• There are many unique properties
• Further investigation of toxicity is needed
• There are many ways to synthesis
• Method of synthesis depends on financial
needs and amount of product desired
• There are many exciting applications of carbon
nanotubes due to their outstanding & novel
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