Properties, Preparation methods and Applications of Carbon nanotubes.

1. Naveed Akhtar
LS1201201

2. Introduction
Types
Properties
Production
Applications
Conclusion
References
Questions

3. Allotropes of carbon with a cylindrical structure
Composed entirely of sp2 bonds
Walls are formed by one-atom-thick sheets of carbon called graphene
Can be capped on the ends with buckyballs or open ended
Diameter range 0.4–40 nm but the length reach upto18.5 cm

4. Nanomaterials
Organic
Fullerenes
C60
C90
Carbon
Nanotubes
Multi-walled
Single-walled
Inorganic
Metal Oxides
ZnO2
CeO2
Metals
Au
Ag
Quantaum Dots
CdSe
Classification
Naveed Akhtar

5. Armchair Zig-Zag

6.  Multiple rolled layers of
graphene sheets
Russian Doll model, sheets
of graphite are arranged in
concentric cylinders
Parchment model, a single
sheet of graphite is rolled
in around itself
 Interlayer distance ~ 3.4Å

7. A) Young Modulus (stiffness)
 Carbon nanotubes 1250 GPa
 Carbon fibers 425 GPa (max.)
 High strength steel 200 GPa
B) Tensile strength (breaking strength)
 Carbon nanotubes 11- 63 GPa
 Carbon fibers 3.5 - 6 GPa
 High strength steel ~ 2 Gpa
C) Density
 Carbon nanotube (SW) 1.33 – 1.40 gram / cm3
 Aluminium 2.7 gram / cm3
Carbon nanotubes are the strongest ever known material

8.  Armchair structure nanotubes show
the metallic electrical properties
 Chiral structure nanotubes are
semiconductors
 Metallic nanotubes can carry an
electrical current density of 4×109
A/cm2 which is more than 1,000
times greater than metals such as
copper
 Electrons propagate only along the
tube's axis, so CNT referred to as
one-dimensional conductors

9.  All nanotubes are expected to be very good thermal
conductors along the tube, but good insulators
laterally to the tube axis.
 It is predicted that carbon nanotubes will be able to
transmit up to 6000 watts per meter per Kelvin at
room temperature; compare this to copper, a metal
well-known for its good thermal conductivity, which
transmits 385 watts per meter per Kelvin.
 The temperature stability of carbon nanotubes is
estimated to be up to 2800oC in vacuum and about
750oC in air

10.  Because of the very small structure of CNTs, the tensile strength of
the tube is dependent on its weakest segment in a similar manner
to a chain, where the strength of the weakest link becomes the
maximum strength of the chain.
 High level of defects can lower the tensile strength up to 85%
 Low thermal conductivity
 Low Electrical properties
Defects can occur in the form
of atomic vacancies
Crystallographic defect

11. Common Methods

12.  Uses two carbon electrodes
that are separated by 1 mm
and located in a partial
vacuum
 25 V is applied across the
electrodes, causing carbon
atoms to be ejected from
positive electrode and carried
to negative electrode where
they form nanotubes
• If no catalyst – multi-walled
nanotubes form
• If cobalt used as catalyst, single-
walled nanotubes with diameters 1 to
5 nm and lengths ~ 1 m

13.  Starting material is graphite with traces of Co and Ni that act
as nucleation sites in formation of nanotubes
 Graphite work piece is placed in quartz tube filled with argon
and heated to 1200°C
 A pulsed laser beam is focused on surface, causing carbon
atoms to evaporate from the bulk graphite
 Argon moves carbon atoms to cool copper surface, where
they condense, forming nanotubes with diameters 10 to 20
nm and lengths ~ 100 m

14.  Starting material is hydrocarbon gas such as methane (CH4)
 Gas is heated to 1100°C, causing it to decompose and release
carbon atoms
 Atoms condense on cool substrate to form nanotubes
 Substrate surface may contain metallic traces that act as
nucleation sites for nanotubes
 CVD process can be operated continuously, making it attractive
for mass production

16. Structural Applications
Electrical Applications
Energy Storage Applications
Biomedical Applications

17. Weaving them into clothes to create stab-
proof and bulletproof clothing
CNTs are being coated on the fiber
surface for preparing multifunctional
fabric including antibacterial, flame
retardant
CNT composites that incorporate tougher
materials (i.e. Kevlar)

18.  Field Emission Display
( FED)
Uses electron beam
to produce color
images
 Nano electrical cables
and wires
FED LCD CRT EL
Low Cost
Wide
Viewing
Angle
Rugged
Sharpness
Low Power
High
Resolution
Thin
Lightweight

19. Paper batteries
Solar cells
Ultracapacitors
Hydrogen storage
Physical or chemisorption
Liionbattery

20. Designing novel carbon nanostructures for hydrogen storage
G. Dimitrakakis, G. Froudakis, and E.Tylianakis
Pillared graphene provides a stable architecture for enhanced fuel storage
8 March 2009, SPIE Newsroom. DOI: 10.1117/2.1200902.1451
Pillared graphene consists of CNTs and graphene sheets combined to form a 3D
network nanostructure

21. Ferromagnetic nano-container for diagnostic and therapy of cancer
1.Transfer of (functionalized) ferromagnetic nanotubes in cells
2.Manipulation by external magnetic fields (e.g. alignment, heating)
3.Detection of magnetic particles by magnetic probes (SQUID, NMR,
etc.)

22.  Because of their unique properties CNT are
making their way in a wide range of fields from
engineering to medicine.
 However, there are concerns over the similar shape
of nanotubes and asbestos fibers, which are known
to cause damage to the lungs in conditions such as
mesothelioma.
 Scientists are therefore trying to work out if there
are any adverse effects that nanotubes might have
on human health.
 In a new study on mice, researchers found that
inhaling nanotubes affected the function of T-cells,
a type of white blood cell that organizes the
immune system to fight infections.

23. Having unique properties
Many ways to synthesize
Method of synthesis depends on finances
involved and amount of product desired
There are many exciting applications of
carbon nanotubes
Special properties & potential
applications make them material of future
Naveed Akhar

24.  http://www.news-medical.net/news/22799.aspx
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 Hong, Seunghun; Sung Myung (2007). "Nanotube Electronics: A flexible
approach to mobility". Nature Nanotechnology 2: 207–208.
doi:10.1038/nnano.2007.89
 Meo, S.B.; Andrews R. (2001). "Carbon Nanotubes: Synthesis, Properties,
and Applications". Crit. Rev. Solid State Mater. Sci. 26(3):145-249: 145.
doi:10.1080/20014091104189.
 Kolosnjaj J, Szwarc H, Moussa F (2007). "Toxicity studies of carbon
nanotubes". Adv Exp Med Biol. 620: 181–204. PMID 18217344
 Ebbesen,T.W.; Ajayan, P. M. (1992). "Large-scale synthesis of carbon
nanotubes". Nature 358: 220–222. doi:10.1038/358220a0
 http://www.nanowerk.com/spotlight/spotid=4154.php
 http://www.azonano.com/details.asp?ArticleID=980#_Energy_Storage
 http://www.azonano.com/details.asp?ArticleID=1561
 http://www.nanotechnology.de/ntforum/download/16_Buechner_Leibniz_I
FW.pdf