2. Engineering applications
• Used as hydrogen storage medium,
semiconductors, sensors, nano-biotechnology
and bio medical engineering.
• Hydrogen can be stored in nanotubes of
carbon in fuel cells.
• Carbon nanotubes can be replaced platinum
catalyst in fuel cell.
• CNTs are the best medai for prodcution of
electricity in fuel cells.
3. Introduction
• In recent years, nanoscale science and
technology grown rapidly, with widespread
applications in the fields of medicine,
computing, electronics and scientific
exploration.
• Nanoscale is usually defined as smaller than a
one tenth of a micrometer in at least one
dimension, though this term is sometimes
used for even smaller materials.
4. Definitions
• NANOCHEMISTRY is the science of tools,
technologies and methodologies for chemical
synthesis, analysis and biochemical analysis
performed in nanoliter to femtoliter.
• NANOPARTICLES are the particles within the
size ranging from 1-50nm
• NANOMATERIALS are the materials having
components within size less than 100nm
5. • A nanometre is a unit of length in the metric
system, equal to one billionth of a metre. The
name combines the SI prefix nano- with the
parent unit name metre).
• It can be written in scientific notation as
1×10−9
m, in engineering notation as 1 E−9 m,
and is simply 1 m / 1,000,000,000.
6. One dimensional nanomaterial called NANOLAYER
Two dimensional nanomaterial called
nanotube
Quantumdots-3D nanomaterial
7. Carbon nanotubes
• These are discovered by S. Iijima in 1991
• These are allotropes of carbon with
nanostructure with length-to-diameter ratio
greater than 100,00.
• These are considered as sheet of graphite
rolled into a cylinder.
• These have a very broad range of electronic,
thermal and structural properties.
8. Single walled nanotubes(SWNTs)
• The diameter of SWNTs is 1nm, with a tube
length of many millions of times longer.
• These can be obtained by wrapping a one-
atom thick graphite into seamless cylinder.
• These are very important variety of nanotubes
with ELECTRIC properties.
9. • Based on wrapping of graphene sheet these
nanotubes are classified as
• Armchair (n=0),Zigzag (n=m),chiral
10. Multi-walled nanotubes (MWNTs)
• MWNTs consists of rolled layers of concentric
tubes of graphite. The inter layer distance in
multi walled nanotubes is approximately 3.3A.
• These exhibits both metallic and semi
conducting properties.
• Russian Doll model:no of graphene sheets
wrapped
• Parchment model:single sheet of graphene
rolled in to no of layers like news paper.
11. Synthesis of carbon nanotubes
• ARC DISCHARGE METHOD
• LASER ABLATION METHOD
• CHEMICAL VAPOUR DEPOSITION METHOD
12.
13.
14.
15. Properties of nanotubes
• STRENGTH: carbon nanotubes are the stiffest
materials in terms of tensile strength and
elastic modulous. Density of these tubes is
1.3-1.4g/cm3
• This property is due to the sp2
carbon-carbon
bonds.
• Hardness of nanotubes was found to be the
highest.
16. • ELECTRICAL properties of nanomaterials
depend on the symmetry and unique
electronic structure of graphene.
• If n=m (armchair) metallic
• If n-m is multiple of 3 then the nanotubes are
semiconducting.
• The atoms in these nanotubes posses great
vibrational properties.
17. In catalysis
• Catalysts having CNTS makes a reaction safer,
milder and more selective.
• Theses can be used catalysts themselves or as
catalyst additives or as catalyst supportive.
• CNTs along with ruthenium are used for the
hydrogenation of cinnamaldehyde.
• And some chemical reactions are carried out
in nanotubes.
18. Medicinal applications
• CNTs are used in drug delivery systems, health
monitoring, bio-sensing methods and in
disease treatment.
• Can be used in altering the function of
immune cells.
• Can be used as multifunctional biological
transporters.
19. FULLERENES
• A third and newly discovered allotrope of
carbon after graphite and diamond is
BUCKMINSITER FULLERENE named in the
honor of American Architect Buckminster
Fuller, with a chemical formula of C60 .
• C60 resembles the shape of domes designed by
Fuller
20. Types of Fullerenes
• Spherical fullerenes: they look like a soccer
ball and often called Bucky balls
• Cylindrical fullerenes: these are called carbon
nanotubes or buckytubes
• Planar fullerenes: graphene is an example
planar fullerene sheet
21. DOME built by Buckminster Fuller
Buckminster
Fullerene
22. • Fullerenes are prepared by vaporizing
graphite rod in a helium atmosphere.
Mixtures of fullerenes are formed. These
mixtures are separated by solvent extraction.
• Fullerenes are the class of closed cage carbon
molecule characteristically containing 12
pentagons and a variable number of
hexagons.
23. • The C60 attains a icosahedron shape with 60
vertices, 32 faces.
• Another elongated molecule is C70.
• By trapping C60 R E Smaelly predicted that a
molecule with formula C240 called RUSSIAN
ROLL exsists.
24. Properties
• These exists as discrete molecules
• These are in mustered colored.
• Soluble in common organic solvents
• Dissolves completely in benzene forms a
magenta solution
• These are very tough and with highest tensile
strength.
• Thermally stable up to 600oC.
25. Applications
• Used as organic photo-voltaics
• These can also be used as ferromagnets
• Used as lubricants
• It was found that these fullerenes are active
towards HIV-1 virus.
• Alkali metal fullrides are used as
superconductors
