A short description about Graphene. Gives information about the discovery, properties, applications. This short file contains all the major information about graphene and appropriate references for further research.

1. Seminar Report
Graphene
-Tanmay Bagree (MM15B035)
History and Description
Graphene is the world’s first 2-D Material to be discovered ever and hence has a lot of different
unique properties. These features created a great importance of Graphene among researchers and
scientists.
Graphene does not have a fixed definition and hence, it can be described in a lot of different ways: -
1. It is the basic structural unit for other allotropes of Carbon like Carbon Nanotubes, Fullerenes,
Graphite etc.
2. It can hence be also called as single layer Graphite, unrolled Carbon Nanotubes, unwrapped
Fullerenes.
3. It is a single atom thick layer of a honeycomb lattice made up of Carbon atoms.
4. It is a collection of many benzene rings connected to each other side by side.
Originally the term ‘Graphene’ was coined by Hanns-Peter Boehm in 1962 when he was trying to
give a name to the single-layer carbon foils. The name was thought of as ‘Graphite’ + ‘ene’.
History: -
 Since the mid-1850s, people have stipulated that a lamellar structure of graphite oxide should
exist.
 After the discovery of the structure of Graphite in 1916, research started to be carried out to
find ways to isolate graphene.
 In 1970s single layer of Graphite (Graphene) was isolated on the top of other materials. This
was called ‘Epitaxial Graphene’. This helped in getting to know about the atomic structure of
Graphene.
 From 1990 to 2004, many attempts were
made to isolate a single layer of Graphene
but nothing smaller than 50 to 100 layers
could be obtained. The mechanisms used
were chemical and mechanical exfoliation.
 Finally, in 2004, an atom-thick graphene
layer was isolated by Andre Geim and
Konstantin Novoselov using their famous
technique called the ‘Sticky Tape method’.
Discovery
 In 2004, Graphene was finally isolated at the University of Manchester by Andre Geim and
Konstantin Novoselov.
 Their method of isolating Graphene was something unique and was actually discovered by
accident.
 Their method was called the ‘Sticky Tape method’. Some steps of this method are: -
1. We take an ultra-pure sample of Graphite.

2. 2. With the help of normal sticky tape, we remove some multilayer thick graphite from
the complete sample.
3. Now bring another sticky tape in contact with the previous one and then separate them.
This will cause the multilayer graphite on the sticky tape to divide into two.
4. We carry out this process multiple times until we get a single layer Graphene.
5. We pass this single layer to thin Silicon Oxide wafer to remove it from the sticky tape.
 Andre Geim and Konstantin Novoselov won a Nobel prize in Physics 2010 for “for
groundbreaking experiments regarding the two-dimensional material graphene”.
Properties
 Structure: -
o It is a crystalline 2-D allotrope of Carbon, with its carbon atoms densely packed in a
2-D hexagonal lattice.
o Each of the Carbon is sp2 hybridised with one sigma bond to each of its three
neighbouring atoms.
o There is a sea of delocalized electrons above and below the Carbon layer, making it a
burger shape.
 Chemical: -
o Graphene is the most reactive form of Carbon.
o Physicists at Stanford University in 2013 reported that the reactivity of a single layer
Graphene is a lot more (approximately a hundred time) more than that of the thicker
sheets.
o Every Carbon atom in Graphene is approachable for reaction from both the sides
because of its 2-D shape.
o Atoms at the edge of Graphene sheets have special properties.
 Electronic: -
o The conduction band and the valence band of
Graphene meet at the Dirac points. There is no
gap between the contradictory to what is seen in
traditional semiconductors.
o The graph of energy v/s momentum for
Graphene gives cones which are called Dirac
cones. This is different from semiconductors as
the graph of semiconductors has paraboloids
which have gap between the two graphs.
o Graphene has remarkable electrons and holes
mobility greater than 15,000 cm2V-1s-1,which is
way more than any other material.
 Optical: -
o Graphene has unique optical properties as a single layer of graphene produces an extra
high opacity for an atom thick layer in vacuum.
o Graphene absorbs approximately 2.6% of green light and 2.3% of red light.
 Electrical Conductivity: -
o Due to the two sea of electrons formed by delocalization of electrons, the conductivity
of electricity id very good of Graphene.

3. o Graphene is the most conductive material in the world. Its conductivity is more than
Silver.
 Thermal Conductivity: -
o Thermal conductivity has become one of the most active areas of research.
o Graphene has a wide range of thermal conductivities.
 Mechanical: -
o Graphene is the world’s strongest material which has been tested till now.
o Graphene has an Intrinsic tensile strength of 1GPa.
o Graphene has a Young’s modulus of 1TPa.
o The Nobel announcement illustrated this by saying that a “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”
 Impenetrability: -
o Graphene has this amazing ability of impermeability. It does not even allow He to pass
through the Graphene sheet.
These were some of the major properties of Graphene. The University of Manchester describes this
extravagant list of properties as: -
 It is 200 times stronger than steel, yet incredibly lightweight and flexible.
 It is electrically and thermally conductive but also transparent.
 It is the world’s first 2-D material and is one million times smaller than the diameter of a
single human hair.
Applications
Due to these varied and unique properties, graphene is being researched upon to discover its different
uses.
Some of the areas which might have a big revolution because of Graphene may be: -
 Membranes: -
o Graphene has the potential to solve one of the world’s biggest problem, that is to
provide pure drinking water to every human being possible.
o The property of Graphene being impenetrable plays a very important role here.
Exploiting that property to modify graphene to become selectively permeable would
give us a new means to purify water. Also, it being ultra-light, thin and flexible helps
more to this cause.
o According to the present research at the University of Manchester, Graphene Oxide
membrane can form an effective barrier for water purification.
o This application also increases research in the field of water desalination and gas
separation.
o Graphene membranes might also find a large market in the packaging industry as its
properties make it perfect as a packaging option of food stuff.
 Composites and Coatings
o Composites are materials made by the combination of two or more materials with
different properties to obtain a material with certain specific properties.
o Graphene has some amazing properties, which makes it an ideal component to make
composites.

4. o Graphene composites can help in creating a rust free future. Mixing graphene with
paint synthesises a coating which can protect metals from atmospheric effects.
o This feature can also be used as a means for weatherproofing of houses.
o Its lightweight property along with its strong nature makes it an ideal material to make
composites for sporting goods. Graphene is presently used in the ‘Graphene Next’
range of tennis rackets made Head company. These rackets are 20% lighter and are
more powerful than the normal rackets.
o Graphene is being researched into about its possible uses in making Formula 1 racing
cars and in aircrafts.
 Energy: -
o Graphene because of its special conductivity can have lots of applications in storing
of energy.
o Graphene can prove as a really worthwhile substitute to lithium ion batteries as it can
hold much more power and is lighter than the lithium battery.
o Graphene supercapacitors can provide large amounts of power compared to its
substitutes. It has been said that Graphene supercapacitors will be able to power
laptops for days.
 Biomedical: -
o Graphene is being actively researched in the field of biomedical.
o The major areas of applications being the production of new medical devices using
graphene, and its application as drug delivery method.
 Sensors: -
o Every atom in graphene is available from both the sides for interaction. This makes
Graphene an ideal sensor.
o Graphene would allow the formation of micro-sensors.
o Graphene-based detectors could prove extra worthwhile in case of chemical warfare.
 Electronics: -
o Graphene can be used as a coating to improve the touch phenomenon of our
smartphones to a large extent. Also, the use of Graphene in the circuitry would make
the process a lot faster.
o IBM created the first integrated circuit (IC) using only Graphene
o Graphene is being tested as a potential substitute to semiconductors because of its
properties. Also, it is being tested by creating photovoltaic cells entirely out of
Graphene.
Hence, all these applications of Graphene have a very good chance of revolutionising the whole
world. Graphene is being called as the ‘World’s new Wonder material’ by many different researchers
and scientists.
References
 http://www.graphene.manchester.ac.uk/
 https://en.wikipedia.org/wiki/Graphene
 https://www.google.co.in
 http://graphene-flagship.eu/
 http://news.discovery.com/
 https://www.youtube.com/