Embed Size (px)
DESCRIPTION
this ppt is about carbon nanotube and their types, process and application.
Citation preview
14/03/20131
Carbon Nanotube
By Ajay pandey MSc sem II(PSEVS203) Department of Environmental ScienceUniversity of MUMBAIKJ SOMAIYA COLLAGE OF SCIENCE AND COMERCEMarch 2013
14/03/2013 2
Introduction Structure Formation Mechanism Synthesis Properties Applications Scope Conclusions
Outline
14/03/20133
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
14/03/20134
Carbon allotropesIntroduction
Diamond
Buckyballs
Graphite
Carbon nanotube
14/03/20135
How large the CNT:
°
Carbon nanotube
cross-section (Relative Scale)
Human hair cross-section80,000 times larger than CNT
Introduction
14/03/20136
Types of Carbon nanotubes
Single-Wall Nanotube (SWNT)
Multi-Wall Nanotube (MWNT)
Introduction
14/03/20137
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
14/03/20138
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
14/03/20139
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
14/03/201310
Nanotube classificationSturucture fromation and mechanism
(10, 10) (10, 5)
Chiral structurreArmchair structure
14/03/201311
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 classificationSturucture fromation and mechanism
14/03/201312
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
14/03/201313
Arc Discharge methodSynthesis
Without Catalyst -MWNT
With Catalyst (Co, Ni, Fe, etc.)-SWNT
Electrodes are composed of high purity graphitehydrogen gas is the best gas for obtaining high crystallinity MWNTsA direct current of 50 to 100AProducing CNTs in high yield depends on the uniformity of the plasma arc, and the temperature of the deposit forming on the carbon electrode
14/03/201314
Laser Ablation MethodSynthesis
Without Catalyst- Fullerene
With Catalyst(Co, Ni, Fe, etc.)- SWNT
15
Chemical Vapor diposition (CVD)Synthesis
SWCNT
900-1000
2CO → C + CO2
MWCNT
600-800
C2H2 → 2C + H2
14/03/2013 16
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
17
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
18
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
19
In electronics
Carbon Nanotube FED Panel
Carbon Nanotube computer
Application
14/03/201320
CNT in solar panelApplication
Advantages:
• used to amplify the energy absorption and transformation capabilities of current solar panels..• beat current solar cells in terms of cost/performance efficiency.
21
Application
CNT in Composite materialTo improve the properties of polymer, CNT can be incorporated in polymer matrix by physical dispersion or chemical reaction
14/03/201322
Scope
To makeMolecular transistorsField emittersBuilding blocks for bottom-up electronicsSmaller, lighter weight components for next generation spacecraftHydrogen storageSpace elevator
Scope
23
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
24
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
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
14/03/2013\26
THANK YOU
FOR
ATTENTION
