This document is a report on carbon nanotubes written by Ajay Pandey for a class at the University of Mumbai. It begins with an introduction to carbon nanotubes, describing their tubular structure and unique properties. The report then covers carbon nanotube structure formation mechanisms, various synthesis methods including arc discharge and chemical vapor deposition, and properties such as strength and conductivity. Applications discussed include energy storage, electronics, sensors and composite materials. The report concludes that carbon nanotubes have great potential in nanotechnology due to their robust structure and properties, but that further study is still needed on issues like functionalization and biocompatibility.

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Carbon Nanotube
By Ajay pandey
MSc sem II(PSEVS203)
Department of Environmental Science
University of MUMBAI
KJ SOMAIYA COLLAGE OF
SCIENCE AND COMERCE
March 2013

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 Introduction
 Structure Formation Mechanism
 Synthesis
 Properties
 Applications
 Scope
 Conclusions
Outline

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Introduction
 Carbon nanotube is a new carbon allotrope discovered by Dr.
Sumio Iijima1
at NEC (1991).
 CNT is a tubular form of carbon with diameter as small as
1nm, length: few nm to micro meter.
 It has a nanometer-scale hollow tubular structure and a
different atomic arrangement from other carbon allotropes as
graphite, diamond and C60 bucky-ball.
 Its unique and promising properties have attracted the attention
of researchers around the world and led to active R&D efforts
in the industries.
Introduction

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Carbon allotropes
Introduction
 Diamond
 Buckyballs
 Graphite
 Carbon nanotube

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How large the CNT:
°
Carbon
nanotube
cross-section
(Relative
Scale)
Human hair cross-section
80,000 times larger than CNT
Introduction

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Types of Carbon nanotubes
Single-Wall Nanotube (SWNT)
Multi-Wall Nanotube (MWNT)
Introduction

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Structure Formation and Mechanism
Sturucture fromation and mechanism
 CNT can be described as a
sheet of graphite rolled into
a cylinder
 Constructed from
hexagonal rings of carbon
 Can have one layer or
multiple layers
 Can have caps at the ends
making them look like pills

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Construction of a nanotube by rolling up
graphene sheet
 Chirality - twist of the
nanotube
 Described as the vector
R (n, m)
 Φ = 0º, armchair nanotube
 0º < Φ < 30º, chiral
nanotube
 Φ > 30º, zigzag nanotube
Sturucture fromation and mechanism

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Types of chirality
A) armchair structure (n, n) B) zigzag structure (n, 0)
C) Chiral structure (n, m)
A
B
C
Sturucture fromation and mechanism

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Nanotube classification
Sturucture fromation and mechanism
(10, 10) (10, 5)
Chiral structurreArmchair structure

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 MWNTs
 Consists of 2 or more layers of
carbon
 Tend to form unordered clumps
 SWNTs
 Consists of just one layer of
carbon
 Can have greater tendency to
align into ordered bundles
 Used to test theory of nanotube
properties
Nanotube classification
Sturucture fromation and mechanism

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Synthesis Methods of CNT
 Arc Discharge method
- Nanotubes found in soot produced in arc-discharge with catalytic metals such as Fe,
Ni and Co (S. Iijima, 1991).
 Laser Ablation Method
- Nanotubes produced by pulsed YAG laser ablation of graphite target in a furnace at
1200 °C. (R. Smalley, 1996).
 Chemical Vapor diposition (CVD)
- Nanotubes are grown from nucleation sites of a catalyst in carbon based gas
environments (Ethylene, Methane, etc.) at elevated temperatures (600 - 1000 °C).
Synthesis

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Arc Discharge method
Synthesis
Without Catalyst
-MWNT
With Catalyst (Co, Ni,
Fe, etc.)-SWNT
 Electrodes are composed of high
purity graphite
hydrogen gas is the best gas for
obtaining high crystallinity
MWNTs
A direct current of 50 to 100A
Producing CNTs in high yield
depends on the uniformity of the
plasma arc, and the temperature
of the deposit forming on the
carbon electrode

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Laser Ablation Method
Synthesis
Without Catalyst-
Fullerene
With Catalyst(Co,
Ni, Fe, etc.)-
SWNT

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Chemical Vapor diposition (CVD)
Synthesis
SWCNT
900-1000 °
2CO → C + CO2
MWCNT
600-800 °
C2H2 → 2C + H2

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 The chart compares the tensile strength
of SWNT's to some common high
strength materials
 Strength 100X times greater than steel
at one sixth the weight
 Average Young modulus of CNT is
1.8TPa much higher than typical carbon
fiber of 680 GPa
Properties
Properties of Carbon nanotubes

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Potential applications of CNT
Application Area
 Energy storage
- Hydrogen storage
- Lithium intercalation
- Electrochemical supercapcitors
 Molecular electronics
- Field emitting devices
- Transistors
 Nanoprobes and sensors
 Composite materials
Application

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Hydrogen storage
potential sites for hydrogen adsorption within a nanotubes
bundle: (left) hydrogen atoms occupying the interstitial
spaces between the tubes, and (right) hydrogen atoms
inside the tube interior*.
Application

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In electronics
Carbon Nanotube FED Panel
Carbon Nanotube computer
Application

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CNT in solar panel
Application
Advantages:
• used to amplify the energy
absorption and transformation
capabilities of current solar
panels..
• beat current solar cells in
terms of cost/performance
efficiency.

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Application
CNT in Composite material
To improve the properties of
polymer, CNT can be
incorporated in polymer matrix
by physical dispersion or
chemical reaction

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Scope
To make
Molecular transistors
Field emitters
Building blocks for bottom-up electronics
Smaller, lighter weight components for next
generation spacecraft
Hydrogen storage
Space elevator
Scope

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Issues
 The controlled functionalization of CNT has
not yet been fully achieved
 Solubility continues to be an issue
 New purification and characterization
techniques are still needed
 Effect on living cells has been still not studied
well
Scope

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Conclusion
 Application of CNT in various field due to its robust
structure and metallic/ semiconducting properties makes
it one of the promising material in nanotechnology.
 There is saying that good things come in small packages
nanotechnology has certainly materializing this saying
 It has potential of making almost every manufacture
product faster, lighter, stronger, smarter, safer and
cleaner
 Although it is a very important material, effect on living
cell has to be studied in detail
Conclusion

25. references
 Books
 Sulabha k.kulkarni (2007) Nanotechnology principle and practices. New Delhi: capital
publishing company
 Chattopadhyay (2009) introduction to nanoscience and technology. New Delhi: PHL
learning private limited
 Website
 Marty Mulvihill (2013) advancing green chemistry
 http://advancinggreenchemistry.org/tag/green-design/ (accessed 20/2/2013)
 Carbon nanotube synthesis
 http://www.northeastern.edu/nsrg/?page_id=141 (accessed 20/2/2013)
 3. Increasing importance of carbon nanotube
http://www.ncbi.nlm.nih.gov/pubmed/20706831(accessed 20/2/2013)
 4. carbon nanotube http://en.wikipedia.org/wiki/Carbon_nanotube (accessed
20/2/2013)
26/09/2008Carbon nanotube : a leading material – Panjab Waghmare 25

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THANK YOU
FOR
ATTENTION