2. i. WHAT IS GRAPHENE?
ii. PROPERTIES OF GRAPHENE.
iii. SOME PRODUCTION METHODS
iv. APPLICATIONS
v. MAJOR CHALLENGES
vi. REFERENCES
CONTENTS
3. It’s Story….
WHAT GRAPHENE IS?
• It is all started with structure of graphite solved in 1916 –powder
diffraction.
• In 1924 -single crystal diffraction.
•Comes in focus in 2010 when
‘For the Groundbreaking experiments regarding two dimensional material
Graphene’
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. • Andre Geim and Kostya Novoselov
pulled graphene layers from
graphite and transferred them onto
thin SiO2 on a silicon wafer in a
process called either
micromechanical cleavage or the
Scotch tape technique.
Graphene can be seen with help of
1.Transmission electron microscopy.
2.Electron microscopy
3.Optical microscope
STRUCTURE……
6. 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.
7. • 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.
8. • one-atom-thick crystal can be
seen with the naked eye because
it absorbs approximately 2.3% of
white light. see FIG.
• Graphene's unique optical
properties produce an
unexpectedly high opacity for an
atomic monolayer in vacuum
OPTICAL
FIG; 4 inch scale graphene film on
Stretchable Substrate
THERMAL
• A graphene sheet is thermodynamically most stable
1.only for molecules larger than 24,000 atoms
2.Size greater than 20 nm
• Thermal conductivity is measured to be between (4.84±0.44) × 103 to
(5.30±0.48) × 103 W·m−1·K−1
9. • The flat graphene sheet is unstable with respect to scrolling
i.e. bending into a cylindrical shape
• As of 2009, 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).
• 1 square meter graphene hammock would support a 4 kg cat
but would weigh only as much as one of the cat's whiskers, at
0.77 mg (about 0.001% of the weight of 1 m2 of paper)
MECHANICAL
10. 1. NANOSTRIPES- APPLICATION IN NEW FIELD OF SPINTRONICS
2. GRAPHENE OXIDE (GO)- USED IN WATER REMEDIATION AND REACTIVE GAS
ADSORPTION (ENVIRONMENTAL APPLICATION)
3. SOLUBLE FRAGMENTS OF GRAPHENE-
(THROUGH CHEMICAL MODIFICATION)
4. 3D GRAPHENE (self-supporting 3D graphene has not yet been produced)
5. BILAYER GRAPHENE - Bilayer graphene typically can be found either in
twisted configurations where the two layers are rotated relative to each other.
OTHER FORMS OF GRAPHENE
11. 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)
12. 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)
3. REDUCTION OF GRAPHITE OXIDE
4. METAL CARBON MELT
5. SOLVENT EXFOLIATION
6. CARBON DIOXIDE REDUCTION
7. NANOTUBE SLICING
FIG METAL CARBON MELT
13. 1 MEDICINE - Graphene is reported to have enhanced PCR by increasing
the yield of DNA product
2. INTEGRATED CIRCUITS - For integrated circuits, graphene has a high
carrier mobility
3. TRANSISTORS - Researchers demonstrated four different types of logic
gates, each composed of a single graphene transistor.
In 2013 researchers reported the creation of transistors printed on flexible plastic that operate at
25-gigahertz, sufficient for communications circuits and that can be fabricated at scale. They grow
large graphene sheets on metal, then peel it off and transfer it to the plastic
4. TRANSPERENT CONDUCTING
ELECTRODE
APPLICATIONS
FIG TRANSPERENT CONDUCTING ELECTRODE
15. CHALLENGES TO UNLOCK
COST REDUCTION
HANDELING
GROWTH ON WAFER SCALE
CHALLENGES IN MAKING STRONGER COMPOSITE MATERIAL
APPLICATION IN AIRCRAFT PARTS
LOW COST- HIGH SENSITIVITY SENSORS
APPLICATION IN ELECTRICAL ENERGY STORAGE
16. REFERENCES
1. High Quality, Scalable Graphene Production
Doug Speight, Ivan Vlassiouk
US Department of energy,
2. Graphene Technology: Roadmap to Applications
Andrea C. Ferrari
Department of Engineering, Cambridge University, Cambridge, UK
3. Environmental applications of graphene-based materials
Alina Catrinel Ion1, Ion Ion1, Florinela Sirbu2
1.Department of Analytical Chemistry and Environmental Engineering,
Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest
2.Institute of Physical Chemistry “I. Gh. Murgulescu” of the Romanian Academy
4. Adhesion mechanics of graphene membranes
J.S. Bunch n, M.L.Dunn
Department of Mechanical Engineering, University of Colorado,Boulder,CO80309USA
17. 5. Graphene Membranes And Greenhouse Gas Pollution : An Interview With
Professor Scott Bunch
Dr. Scott Bunch
UNIVERSITY OF COLORADO, Colorado,Boulder,CO80309USA
• 6. Large Arrays and Properties of 3-Terminal GrapheneNanoelectromechanical
Switches
• Xinghui Liu , Ji Won Suk , Narasimha G. Boddeti , Lauren Cantley , Luda Wang ,
• Jason M. Gray , Harris J. Hall , Victor M. Bright , Charles T. Rogers , Martin L. Dunn ,
• Rodney S. Ruoff , and J. Scott Bunch *
REFERENCES…..
