VELTECH

Rangarajan and Dr. Sagunthala R & D Institute of Science

and Technology

Dr. MURUGESAN GANESAN

DEPARTMENT OF PHYSICS
 TYPES OF NANOMATERIALS

Nanomaterials are based into various types based on structure and material. Based on
structure, we classify them as
 Zero dimensional
 One dimensional
 Two dimensional
 Three dimensional

Zero dimensional nanomaterials

Materials wherein all the dimensions are measured within the nanoscale

Example : Quantum dots, fullerenes, Core – Shell structure

One dimensional nanomaterials

One dimension of the material is out of nanoscale range

Example: Carbon nanotubes, Nanowires, Nanorods

Two dimensional nanomaterials

Two dimension of the material is out of nanoscale range

Example: Nanolayers, Nanofilms, Nanocoatings

Three dimensional
All the dimensions are out of nanoscale range. These materials have all three dimensions
above 100nm

Example : Nanocrystals

Quantum dots Carbon nanotubes Nanofilms

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 TYPES OF NANOMATERIALS

0D NANOMATERIALS

Quantum dots

Quantum dots (QDs) are man-made nanoscale crystals that that can transport electrons.
When light is illuminated on quantum dots it emit light of various colors based on its size.

Quantum dots absorb the light falling on it and emits light of various wavelength
based on its size. The main reason for this behaviour is, as the size of the nanoparticle
is tuned its band gap gets altered. This results in the emission of various wavelength
of light based on its size.

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 TYPES OF NANOMATERIALS

APPLICATIONS OF QUANTUM DOTS

It is used in
• Solar cells as absorbing photovoltaic material
• LEDs, since it emits different colour light based on its size. Quantum LEDs are
used in televisions for pure colours, longer lifetime, lower manufacturing cost
and lower power consumption.
• Bio imaging – to detect cancer cells at the exact locations (tumor cell targeting).

FULLERENE
• It is a zero dimensional form of graphitic carbon

• A fullerene is an allotrope of carbon whose molecule consists of carbon atoms

connected by single and double bonds

• Fullerenes are denoted by their empirical formula Cn, where n is the number of
carbon atoms.

• Various forms of fullerenes have been found, and their sizes range from 30 to
3000 carbon atoms.

APPLICATIONS OF FULLERENE

It is used for,
• Drug delivery system
• Photosensitizers in treatment of tumour
• Surface coatings
• Cosmetics ( UV whitening cream)
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 TYPES OF NANOMATERIALS

CORE SHELL STRUCTURE

Core–shell type nanoparticles are a type of biphasic materials which have an

inner core structure and an outer shell made of different materials. .

SHELL
CORE

Different core shell nanoparticles are,

a) Spherical core/shell nanoparticles
b) Hexagonal core / shell nanoparticles
c) Multiple small core materials coated by single shell material

(a) (b) (c)

APPLICATIONS OF CORE-SHELL STRUCTURE

• Controlled drug delivery

• Specific targeting of tumor cells
• Bio imaging
• Catalytic and electronic applications
• Sensor devices fabrication.

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 TYPES OF NANOMATERIALS

NANOWIRE
A nanowire is a nanostructure, with the diameter of the order of a nanometer
(10−9 meters).

APPLICATIONS OF NANOWIRES
• Data storage
• Batteries and generators – power generation
• Optoelectronic devices
• Bio chemical sensors
• Thermoelectric devices

NANOPEAPODS
It is a hybrid nanomaterial consisting of spheroidal fullerenes encapsulated within a
carbon nanotube.

APPLICATIONS OF NANOPEAPODS
Nanopeapods are used for,
• Nanoscale lasers
• Arrays for quantum computing
• Data storage devices
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 TYPES OF NANOMATERIALS

GRAPHENE

Graphene is an allotrope of carbon in the form of a single layer of atoms in

a two-dimensional hexagonal lattice.
It is the basic structural element of other allotropes, Carbon atom
 Graphite

 Charcoal

 Carbon nanotubes

 Fullerenes

Graphene sheet
CARBON NANOTUBES
A carbon nanotube is a tube-shaped material, made of carbon, having a diameter
measuring on the nanometer scale. Carbon nanotubes have many structures, differing
in length, thickness, and number of layers. The characteristics of nanotubes can be
different depending on how the graphene sheet has rolled up to form the tube causing
it to act either metallic or as a semiconductor.

There are many different types of carbon nanotubes, but they are normally
categorized as either single-walled (SWNT) or multi-walled nanotubes (MWNT).

• A single-walled carbon nanotube is just like a regular straw. It has only one
layer, or wall.
• Multi-walled carbon nanotubes are a collection of nested tubes of continuously
increasing diameters. They can range from one outer and one inner tube
(a double-walled nanotube) to as many as 100 tubes (walls) or more. Each tube is
held at a certain distance from either of its neighbouring tubes by interatomic
forces.
Based on symmetry carbon nanotubes are
classified as,
• Armchair
• Zig-Zag
• Chiral
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 TYPES OF NANOMATERIALS

GRAPHENE SHEET CARBON NANOTUBE SINGLE WALLED MULTI WALLED

Arm Chair
The graphene sheet is rolled up along the
vector smaller that the chiral angle

Zig-Zag
The graphene sheet is rolled up along a
vector greater than the chiral angle

Chiral
In these it is rolled up on the chiral vector

PROPERTIES
• High electrical conductivity
• High tensile strength
• Flexible without damage
• Very Elastic
• High thermal conductivity
• Low thermal expansion coefficient

APPLICATIONS

•Due to its enhanced mechanical strength it is used for applications in tissue

engineering which include bone, muscle and nerve tissues.

• It has dimensional and chemical compatibility with bio molecules and proteins
thus used for drug delivery.

• Due to high mechanical strength many structures have been proposed in

everyday items like clothes, sport gears, combat jackets and space elevators
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 TYPES OF NANOMATERIALS

NANOMATERIALS CLASSIFICATION BASED ON MATERIAL

Nanomaterials are classified into various types based on the materials used,
• Nano metal oxides
• Nano semiconductors
• Nano glasses
• Nano ceramics
• Biological materials
• Nano composites

NANO METAL OXIDES

Metal oxide nanoparticles shows special optical and electronic properties as compared
to those of bulk materials. The metal oxide-based polymer nanocomposites also exhibit
good electrical and optical properties.
Nano metal oxides are generally prepared using various metals like CuO, ZnO, TiO2,
AgO, MgO, SnO2

NANO SEMICONDUCTORS
Nano sized oxide semiconductors have easily adjustable electronic properties. ZnO
nanostructures can be used in the field of optoelectronics, sensors, transducers and bio
medical applications. ZnO nanostructured semiconductors have been used as UV
blocker in sun screens. Nanostructured tin oxide (SnO2) has a wide band gap with
numerous applications as Gas sensors, transparent conducting electrodes, transistors.

Examples of nanosemiconductors: ZnO, ZnS, CdS, CdSe, CdTe, GaN, GaP, GaAs

NANO CERAMICS
Nanoceramics are a type of nanoparticles that are composed of ceramic materials at
nanoscale. These nanoceramics are inorganic, heat resistant, non metallic.

Example: Carbides, borides and nitrides – SiC (Silicon carbide), Tungsten Carbide

NANO GlASSES
Metallic glasses with nanometer-sized structures are called as nano glasses. It exhibites
remarkable properties such as the improved mechanical, biological, magnetic and
catalytic properties in comparison to the corresponding melt-quenched glasses of
identical overall composition.

Example: MgO – Al2O3 – SiO2

Li2O – Al2O3 – SiO2
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 TYPES OF NANOMATERIALS

NANO COMPOSITES

Nanocomposite is a multiphase solid material where one of the phases has one, two or
three dimensions of less than 100 nanometres (nm).
Composites are combinations of two materials in which one of the materials called the
reinforcing phase(in the form of fibres, sheets or particles) and it is embedded in other
materials called matrix phase.
Based on the type of material used, nanocomposites are classified as

 Ceramic matrix composites –

SiC, Al2O3, Al2O3-SiC, Boron carbide\

 Metal matrix composites

Al, Mg, Ti, Cu alloys

 Polymer matrix composites

Starch, cellulose, Poly vinyl alcohol, poly ethylene gylcol, gelatin

BIOLOGICAL MATERIALS

A biomaterial is a natural or man made material which comprises a part of living

structures or biomedical devices that performs or replaces a natural function.

• It is a non-viable material used in medical devices intended to interact with

biological systems.

• Biomaterials are used to make devices that would be in close or direct contact with
the body to replace faulty materials.
Example: Titanium dioxide, Hydroxyapatite, Steel, Gold, Silver, Cobalt