NANOTECHNOLOGY

NANOSCIENCE

Emerging area of science which concerns itself with

the study of materials that have very very small

dimensions.

It involves chemistry, physics, biology, mathematics,

cognitive science and life sciences.

NANOSCIENCE

It is the study of phenomena and manipulation of

ultra-small structures or materials at atomic,

molecular and macromolecular scales, where

properties differ significantly from those at a larger

scale.

Simply the study of nanostructures.

NANOTECHNOLOGY

Nanotechnologies are the design, characterization,

production and application of structures, devices and

systems by controlling shape and size at the

nanometer scale.

Implementation and application of nanomaterials.

THE NANOMETER SCALEIt is conventionally defined as 1 to 100 nm.

One nanometer is one billionth of a meter (10-9m).

Word ‘nano’ derived from the Greek word for dwarf.

Size range is normally set to a minimum of 1nm to

avoid single atoms or very small groups of atoms

being designated as nano objects.

WHAT IS A NANOMATERIAL

A nanomaterial is an object that has at least one

dimension in the nanometer scale (approximately 1 to

100 nm).

Nanomaterials are categorized according to their dimensions :-Nanomaterial dimension ExampleAll three dimensions <

100nm

Two dimensions < 100 nm

One dimension < 100 nm

Nanoparticles, quantum dots, nanoshells, nanorings, micro capsules

Nanotubes, fibres, nanowires.

Thin films, layers and coatings

EXAMPLES TO ELICIT THE CONCEPT OF ‘NANO’

Our fingernails grow at the rate of 1nm per second.

The head of a pin is about 1000000 nm in diameter.

A human hair is about 80000 nm in diameter.

A DNA molecule is 1-2 nm wide.

The transistor of a latest generation Pentium Core

Duo processor is 45 nm.

WHAT MAKES NANO SPECIAL1. A material (eg: metal) when in a nano-sized form can

assume properties ( electrical conductivity, color,

strength and weight) which are very different from

those when the same material is in a bulk form.

Eg : Bulk silver is non- toxic, whereas silver

nanoparticles are capable of killing viruses upon

contact.

WHAT MAKES ‘NANO’ SPECIAL

2. Nanomaterials have an increased surface to volume

ratio compared to bulk materials. This has

important consequences for all those processes that

occur at the surface of a nanomaterial, such as

catalysis and detection.

HISTORICAL ASPECTS OF NANOTECHNOLOGYJames clerk Max-well (1867) :- The first mention of the

distinguishing concepts in nanotechnology. Richard Adolf Zsigmondy ( 1914) :- First to use nanometer for

characterizing particle size. He determined it as 1/10,00,000 of millimeter.

Richard Feynman ( 1959) :- The concept of technology about nanomaterials attribute Nobel prize to Feynman.

Eric Drexler (1980) :- concept of nanotechnology to engineering through the concept of molecular nanotechnology was first applied by him.

H.W Kroto & R Smalley (1985) :- Discovery of fullerenes.

FATHER OF NANOTECHNOLOGY

LYCURGUS CUP

It is a piece of Roman glass work, dating from the fifth century. When illuminated from the outside, the cup appears green. When illuminated from inside, it appears ruby-red. The reason for this dichroism was due to the presence of nano sized particles of silver (66.2%), gold (31.2%) and copper (2.6%) upto 100 nm in size embedded in the glass.

FARADAY’S STUDIES ON GOLD COLLOIDSMichael Faraday who was the first to conduct systematic

studies on the properties of metal colloids, in particular gold.

ADVANCED NANOMATERIALS

FULLERENECARBON NANOTUBE

ADVANCED NANOMATERIALSCARBON NANOTUBES ( CNT’S)

Allotropes of carbon with cylindrical nanostructure. It can appear as single-

wall nanotubes (SWNT’S), with a diameter of approximately 1.4 nm or

multi- wall nanotubes (MWNT’S) consisting of 2-30 concentric tubes with

an outer diameter of 30-50 nm. CNT’S are the strongest and stiffest

materials yet discovered in terms of tensile strength and elastic modulus

respectively.

Applications include nano medicine (drug delivery), environment( chemical sensors), energy etc.

• FULLERENES Fullerene is also an allotrope of carbon, popularly known

as Buckminster fullerene (C-60). It has a truncated icosahedron structure. It is black powdery material, tough and thermally stable. Icosahedron is a polygon with 60 vertices and 32 faces, 12 of which are pentagonal and 20 are hexagonal.

Applications :- used as lubricant due to it’s spherical structure.

used as superconductor when mixed with alkali metals.Used as soft ferromagnet.

APPLICATIONS OF NANOTECHNOLOGY

1. In medicine and healthcare (nanomedicine) Use nanomaterials and nano enabled techniques to

diagnose ,monitor, treat and prevent diseases.

2. Environment (pollution prevention)

Remediation for environmental pollution using metal

nanoparticles, semiconducting nanoparticles, aero gels, solid

adsorbents etc.

3. In computers

Nanomaterials and nanoelectronics holds the promise of

making computer processors more powerful.

4. In Robotics

Nano robotics is an emerging technology field of creating

machines or robots whose components are at or close to the

microscopic scale of a nanometer.

5. In electronics ( nanoelectronics) In semiconductor chips, laser technology, lithium-ion

batteries, nanoradios, bio- nano generators, solar cells etc.

6. In vehicles A series of nanomaterials [ metal- nano powders, metal-

nano colloids, metal nano clusters etc.] are used in automobile market.

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