Presentation of CNT based composites which is helpful for material science engineering students of B.Tech for a brief review of composites.

1. PRESENTATION
ON
CARBON NANOTUBE BASED
COMPOSITE
MADE BY-
B.VINITH
DEPARTMENT OF METALLURGICAL
ENGINEERING, NIT RAIPUR
20-Oct-18 1

2. CONTENTS
What is CNT?
TYPES
Discovery
Production
Properties
Applications
Polymer based
composites
Processing methods
Merits & Demerits

3. WHAT IS ACARBON NANOTUBE?
• A carbon nanotube is a tube-shaped material made of Carbon,
having a diameter measuring on the nanometre scale
• Carbon nanotubes are formed from essentially the graphite sheet
and the graphite layer appears somewhat like a rolled-up continuous
unbroken hexagonal mesh and carbon molecules at the apex of the
hexagons
• Nanotubes are the members of the fullerene structure family
• Their name is derived from their long, hollow structure with the walls
from the one atom thick sheets of carbon called graphene.
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4. Types of carbon Nanotube
• Classified mainly in two types [29]
• 1. single walled Nanotubes
• 2. MultiWalled Nanotubes
OTHER RELATED STRUCTURES:
• GRAPHENEATEDCARBON NANOTUBES(G-CNTS)
• NITROGEN DOPEDCARBON NANOTUBES(N-CNTS)
• PEAPOD
• CUP-STACKEDCARBON NANOTUBES
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5. SINGLE WALLED NANOTUBE
• Diameter:-1nm
• Band gap:-0-2ev
• A one atom thick layer of graphene
into seamless cylinder
• Their electrical conductivity can show
Metallic or Semiconducting behaviour.
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6. MULTI WALLED CARBON NANOTUBES
• Multi walled nanotubes(MWNT)
Consists of multiple rolled layers
(concretic tube) of Graphene.
• Interlayer distance:-3.4Ä
• To describe structure of MWNT there are
Two models:-
1. Russian doll model
2. Parchment model
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7. GRAPHENATED CARBON NANOTUBE:-
• They are new hybrids that combines graphitic foliates
grown along the sidewalls of MWNT.
NITROGEN DOPED CARBON NANOTUBE
• These are used for enhancing storage capacityof Li-ion
batteries.
• N-doping provides defects in the walls of CNTs allowing for Li-
ions to diffuse into inter-wall space.
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8. PEAPOD:-
• A carbon peapod is a novel hybrid carbon
Material which traps fullerene inside
a carbon nanotube.
CUPSTACKEDCARBON NANOTUBE:-
• CSCNTs exhibit semiconducting behaviours
due to the stacking microstructure
of graphene layers.
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9. DISCOVERY
• 1952
Radushkevich and Lukyanovich publish a paper in the soviet journal of
physical chemistry showing hollow graphitie carbon fibres that are 50
nanometers in diameter.
• 1979
John abrahamson presented evidence of carbon nanotubes at the14th
Biennial conference of carbon at PENNYSYLVANIA state university.
• 1981
A group of soviet scientists published the results of chemical and
structural characterisation of carbon nanoparticles produced by a
thermocatalytical dispropornation of a carbon monoxide.
• 1991[1]
Nanotubes discovered in the soot of arc discharge at NEC, by Japanese
researcher SUMIO LIJIMA.20-Oct-18 9

10. PRODUCTIONOF CARBON NANOTUBES
• There are mainly four methods of production of CNTs-
1. ARC DISCHARGE METHOD
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11. 2.LASER ABLATION METHOD
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12. 3.CHEMICAL VAPOUR DEPOSITION
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13. 4.BALL MILLING METHOD
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14. PROPERTIES
1.ELECTRICAL CONDUCTIVITY-
Because of the symmetry and unique electronic structure of
graphene,nanotube has a very high current capacity.
2.STRENGTH AND ELASTICITY-
Carbon nanotubes are the strongest,flexible and stiffest materials
yet discovered in terms of tensile strength and elastic modulus
respectively.
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15. 3.THERMAL CONDUCTIVITY & EXPANSION
All nanotubes are expected to be very good thermal conductors along
the tube but good insulators laterally to the tube axis.It can exhibit
superconductivity below 20k.
4. FIELD EMISSION-
Under the application of strong electricfield,tunneling of electrons from
metal tip to vacuum results in field emission phenomenon.It is through
electronfield emission and visible light spectrum.
5. ASPECT RATIO-
It has a higher aspect ratio,inferring that a lower cnt load is required
compared to other conductive addivites to achieve similiar electrical
conductivity.
6. EMWAVE ABSORPTION-
There has been some research on filling MWNTS with metals, such as
Fe,Ni,Co,,etc to increase the absorption effectiveness of MWNTs in
the microwave regime.
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16. APPLICATIONS
1. Biological & biomedical research-
• Soft X-Ray,
• Bone Mineral content,
• Tissue evaluation.
2. MECHANICAL-
• Actuators
• Loudspeakers
• Flywheel
3. ELECTRICAL-
• Super Capacitors
• Paper Batteries20-Oct-18
16

17. 4.OPTICAL-
• Pyroelectric infrared detectors
• Biomedical imaging and sensors
5.MICROELECTRONICS-
• Transistors
• Solar cells
• LCD Screens
• Nano Radio
6.ENVIRONMENTAL-
• Environmental Remediation
• WaterTreatment
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18. 7. MATERIAL SCIENCE-
COMPOSITES-
• Nanonetwork
• Nanorobotics
• Future soldier
• Advanced Modular
Armour Protection(AMAP)
• Nano Armour
• Nanotough
• Materiomics
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19. • Polymers have good flexibility, low density, low
melting pt. and easily fabricable.
• CNT as a filler material for polymer based
nanocomposite..[20]
• Various polymer-based matrices are:-
conventional polymers such as thermoplastics, thermosets
or elastomers as well as conjugated polymers). [13]
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20. NANOCOMPOSITE FABRICATION
TECHNIQUES
• Our motive is to deagglomerate the CNTs and
realize their uniform dispersion inside the matrix.
• Various techniques are-
1. Solution processing
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Used for:-thermosetting matrices based composites
Film casting and solvent evaporation leaving behind nanocomposite film/sheet
Mixing with polymer solution
Dispersion of nanotubes in a suitable solvent

21. 20-Oct-18 21

22. 2. MELT PROCESSINGTECHNIQUE-
Cooling in semisolid strands
HOMOGENISATION ZONE-where matrix is homogenised with CNTs
CNTs are fed through another hopper intensive shearing and kneading action breaks
CNTs into small tubes and mixing occurs
Polymers granules are inserted into rotating screws &pushed forward and melted to
form viscous liquid
Used for-thermoplastic based matrices
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23. 20-Oct-18 23

24. 3. INSITU PROCESSING-
• Used for insoluble polymer based matrices.
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Insitu polymerisation
reaction takes place
leading to formation of
CNT polymer based
nanocomposite
Functionalised CNTs are
dispersed in monomers

25. MERITS-
Carbon Nanotubes have a number of advantages-
• High thermal and electrical conductivity
• Optical properties
• Flexibility
• Increased stiffness
• High tensile strength(100 times stronger than steel per unit
of weight)
• Light weight
• Range of electro-conductivity
• Ability to be manipulated yet remain strong
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26. DEMERITS
• Toxicity:-
under some conditions, nanotubes can cross membrane
barriers,which suggests that if a
raw materials reach the organs they can induce harmful effects such
as inflammatory and fibrotic reactions.
• CRYSTALLOGRAPHIC DEFECTS:-
As with any material,the existence of a crystallographic defect
affects the material properties.Defects can occur in the form of
atomic vacancies.
• DIIFICULT TO DISPERSE FIBRES IN MATRIX.20-Oct-18 26

27. REFERENCES-
• [1] Iijima, S. Helical microtubules of graphitic carbon. Nature 354,
56–58 (1991).
• [29] Saito, Y., Dresselhaus, G. & Dresselhaus, M. S. Physical
properties of carbon nanotubes.(London and Imperial College Press,
1998).
• [20] Thostenson, E., Li, C. & Chou, T. Nanocomposites in context.
Compos. Sci. Technol. 65,491–516 (2005).
• [13] Saini, P. in Fundamentals of Conjugated Polymer Blends,
Copolymers and Composites (ed.Saini, P.) 449–518 (John Wiley &
Sons,Inc.,2015).athttp://doi.wiley.com/10.1002/9781119137160.ch
• cnt.polymer based.pdf
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28. THANK YOU !
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