ppt on graphene and its uses

1. Submitted by :-
TUSHAR
PANDAGRE
EN DEPT.
RCOEM,NAGPUR

2. Introduction
Graphene, a two dimensional carbon allotrope is a highly versatile material
and its amazing properties make it the strongest and lightest material due to
its ability to conduct electricity and heat better than any other material.
It is expected that graphene will improve the efficiency and performance of
current materials and substances but in the future it will be developed along
with other 2D crystals to create even more amazing compounds.
Since graphene is just one atom thick other materials can be created by
interjecting the graphene layers with other compounds, effectively using
graphene as atomic scaffolding from which other materials are designed.
The development of graphene and discovery of its exceptional properties
aroused interest in other 2D crystals.
High-quality graphene, though a good conductor, does not have a band gap.
In order to use graphene for future nano-electronic devices it is required
that it has a band gap engineered into it, which will reduce its electron
mobility to that of levels currently seen in strained silicone films.

4. • It is almost completely transparent, yet
so dense that not even helium can pass
through it.
• It is the one-atom thick planar sheet
of carbon atoms (graphite), which
makes it the thinnest material ever
discovered.
• 2-dimentional crystalline allotrope of
carbon.
• C-C Bond length is 0.142 nm.
• Graphene Sheets interplanar
spacing is of 0.335 nm.
STRUCTURE

5. Graphene can self-repair holes in
its sheets, when exposed to molecules
containing carbon, such as hydrocarbons.
Bombarded with pure carbon atoms,
the atoms perfectly align into hexagons,
completely filling the holes.
STRUCTURAL
PROPERTIES OF GRAPHENE

6. • Graphene one atom thick are a hundred times more chemically
reactive than thicker sheets. (Stanford university)
• Graphene is chemically the most reactive form of carbon.
CHEMICAL
ELECTRONIC
• Intrinsic graphene is a semi-metal or zero-gap semiconductor.
ELECTRICAL
•Graphene has a remarkably high electron mobility at room
temperature, with reported values in excess of 15000 cm2·V−1·s−1
•It conducts electricity as efficiently as copper and outperforms all
other materials as a conductor of heat.

7. • One-atom-thick crystal can be seen
with the naked eye because it
absorbs approximately 2.3% of
white light.
• Graphene's unique optical
properties produce an
unexpectedly high opacity for an
atomic monolayer in vacuum
OPTICAL
inch scale graphene film on
Stretchable SubstrateTHERMAL
Thermal conductivity is measured to be between
(4.84±0.44) × 103 to (5.30±0.48) × 103 W·m−1·K−1

8. • The flat graphene sheet is unstable with respect to scrolling i.E.
Bending into a cylindrical shape.
• Graphene appeared to be one of the strongest materials
known with a breaking strength over 100 times greater than a
hypothetical steel film of the same (thin) thickness, with a
young's modulus (stiffness) of 1 tpa (150000000 psi).
MECHANICAL

9. 1.MECHANICAL EXFOLIATION : This
involves splitting single layers of
graphene from multi-layered graphite.
Achieving single layers typically requires
multiple exfoliation steps, each
producing a slice with fewer layers, until
only one remains. Geim and Novosolev
used adhesive tape to split the layers.
SOME PRODUCTION METHODS
2. EPITAXY :
Epitaxy refers to the deposition of a
crystalline overlayer on a crystalline
substrate and the graphene–substrate
interaction can be further passivated
•In some cases epitaxial graphene layers
are coupled to surfaces weakly enough (by
Van der Waals forces)

10. Sicilicon-based epitaxy technology for producing large pieces of
graphene with the best quality to date
EPITAXY EXAMPLES :
 Silicon carbide
 Metal substrates
 Copper Vapor Deposition ( CVD)

11. Applications of graphene

12. As graphene offers high electrical
conductivity, thinness, strength and high
electrical conductivity it may help develop
quick and efficient bioelectric sensory
devices, with the ability to monitor such
things as glucose levels, haemoglobin
levels, cholesterol and even DNA
sequencing.
Engineered toxic graphene can also be
used as an antibiotic or even anticancer
treatment. It may also find application in
the process of tissue regeneration due to
its molecular make-up and potential
biocompatibility.
Applications of Graphene
Graphene will find applications not just in electronics but also in
bioengineering, composite materials, energy technology and
nanotechnology.
Biological Engineering

13. It is believed that graphene will be used on a commercial scale in the field
of optoelectronics especially LCDs, touch screens and organic light
emitting diodes (OLEDs). Graphene is almost completely transparent
material and can transmit up to 97.7% of incident light. It also has high
conductivity, hence would be suitable for smartphones, tablet, desktop
computers and televisions.
Recent tests prove that graphene will match the properties of indium tin
oxide (ITO) even in present states. Also it has been shown recently that
the optical absorption of graphene can be changed by adjusting the Fermi
level. Since high quality graphene has a very high tensile strength and is
flexible it can be used for flexible displays.
It is believed that we can eventually see devices such as graphene-based
e-paper and flexible electronic devices.
Optical Electronics

14. • Graphene allows water to pass through, however it is
almost impervious to liquids and gases. Graphene can
be used as an ultrafiltration medium to behave as a
barrier between two substances.
• Graphene is beneficial since it is just one single atom
thick and can be developed as a barrier that measures
pressure and strain electronically between two
substances. A research team at Columbia University
managed to create monolayer graphene filters with
pore sizes as small as 5nm.
• Graphene has a higher strength and is less brittle when
compared to aluminium oxide presently used in sub-
100nm filtration applications. Hence graphene can be
used in water filtration systems, desalination systems
and efficient and economically more viable biofuel
creation.
Ultra filtertion

15. Composite materials
Graphene is stiff, strong and very light. Presently aerospace engineers are
incorporating carbon fibre into the production of aircraft as it is also very
strong and light.
It is anticipated that graphene will be used to create create a material that can
replace steel in the structure of aircraft, improving fuel efficiency, range and
reducing weight. Since it has good electrical conductivity, it will be used to coat
aircraft surface material to prevent electrical damage resulting from lightning
strikes

16. • Graphene can be used as an alternative to ITO
or silicon in manufacturing photovoltaic cells.
Silicon is presently used extensively in
producing photovoltaic cells, however
graphene-based cells may be less expensive.
• Graphene on photon absorption generates
multiple electrons. Also graphene can work on
all wavelengths unlike silicon.
• Graphene-based photovoltaic cells are
flexible and thin and can be used in clothing to
help recharge the mobile phone or even used
as retro-fitted photovoltaic window screens or
curtains to help power the home.
Photovoltiaccells

17. • graphene is being studied and developed to be used to manufacture
supercapacitors that can be charged very quickly, yet also be able to store a large
amount of electricity.
• Graphene- based micro-supercapacitors can be developed for use in low energy
applications such as smart phones and portable computing devices and can be
commercially available within the next 5-10 years.
• Graphene-enhanced lithium ion batteries can be used in much higher energy
usage applications such as electrically powered vehicles, or can be used as
lithium ion batteries are now, in smartphones, laptops and tablet PCs but at
significantly lower levels of size and weight.
Energystorage

18. • Carbon NanoTubes (CNTs) have many used like
Electronics parts, Biomedical, Electrical circuits,
Electrical cables and wires, Actuators, Paper
batteries, Solar cells and Hydrogen storage, and it
usually made from graphene sheet that “roll up”
make the nanotube.
• Graphene will replace copper in nano sutures
because electrical resistance in 40-nanometer-
wide nanoribbons of epitaxial graphene changes
in discrete steps. The ribbons’ conductance
exceeds predictions by a factor of 10. The ribbons
can act more like optical waveguides or quantum
dots, allowing electrons to flow smoothly along
the ribbon edges. In copper, resistance increases
in proportion to length as electrons encounter
impurities.
Nanotechnology

20. THANK YOU