- Nanotechnology is the manipulation of matter on an atomic, molecular, and supramolecular scale where quantum mechanical effects are observed. It involves engineering materials and devices within the nanometer scale (1-100 nm).
- Some examples of nanotechnology include carbon nanotubes, graphene, buckminsterfullerenes, plasmonic nanoparticles, and quantum dots. Nanomaterials are characterized using techniques like atomic force microscopy, scanning electron microscopy, and transmission electron microscopy.
- Properties of materials change at the nanoscale due to increased surface area effects, quantum confinement, and single electron tunneling effects. This allows for applications in areas like energy storage, catalysis, drug delivery, and electronics.
2. Overview
• What is nanotechnology?
• Why nanotechnology is important?
• How to make nanostructures?
• Some examples of nanotechnology?
• Applications
• Summary
• Our work
3. History of useful science
Discovery type Name Age Start date
Industrial Tools Stone 2 200 000 BC
Industrial Metallurgy Bronze 3500 BC
Industrial Steam power Industrial 1764
Automation Mass production Consumer 1906
Automation Computing Information 1946
Health Genetic Engineering Genetic 1953
Industrial Nanotechnology Nano age? 1991
Automation Molecular assemblers Assembler age? 2020?
All three Life assemblers Life age? 2050?
7. History
• Richard Feynman lecture
• American Physical Society meeting
at Caltech on Dec 29, 1959
• “There’s Plenty of Room at the Bottom”
• Greek word Dwarf
• Synthesis via direct manipulation of atoms
• Norio Taniguchi in 1974 used Nanotechnology
• K. Eric Drexler popularized the term "nanotechnology" in his 1986
book Engines of Creation: The Coming Era of Nanotechnology
What I want to talk about is the problem of manipulating and controlling things on a small scale … What are
the limitations as to how small a thing has to be before you can no longer mold it? How many times when
you are working on something frustratingly tiny like your wife’s wrist watch have you said to yourself, “If I
could only train an ant to do this!” What I would like to suggest is the possibility of training an ant to train a
mite to do this … A friend of mine (Albert R. Hibbs) suggests a very interesting possibility for relatively small
machines. He says that, although it is a very wild idea, it would be interesting in surgery if you could swallow
the surgeon. You put the mechanical surgeon inside the blood vessel and it goes into the heart and “looks”
around. It finds out which valve is the faulty one and takes a little knife and slices it out.
9. Why large surface area is important?
• Maximize surface area increases maximize possible reactivity
• Greater amount of substance comes in contact with
surrounding material
• Potent catalysts: greater portion of material is exposed
• Applied in thin films to serve as thermal barriers
• Improve wear resistance of materials
• Makes chemically reactive
• Quantum effects dominates the behavior of material at
nanoscal
10. Characterization of nanoparticles
• Size, morphology and surface charge determination
• Atomic Force Microscopy (AFM)
• Scanning Electron Microscopy (SEM)
• Transmission Electron Microscopy (TEM)
• So on…
11. Characterization of nanoparticles
• Size, morphology and surface charge determination
• Atomic Force Microscopy (AFM)
• Scanning Electron Microscopy (SEM)
• Transmission Electron Microscopy (TEM)
• So on…
12. Characterization of nanoparticles
• Size, morphology and surface charge determination
• Atomic Force Microscopy (AFM)
• Scanning Electron Microscopy (SEM)
• Transmission Electron Microscopy (TEM)
• So on…
13. • Nanoscience and technology is the branch of science that
studies systems and manipulates matter on atomic, molecular
and supramolecular scales (the nanometre scale)
• Nanotechnology is an anticipated manufacturing technology
that allows thorough, inexpensive control of the structure of
matter by working with atoms
Title: insufficient to be upto
14. Graphene
• 2010 Noble prize for Physics to Andre Geim and Konstantin
Novoselov of University of Manchester
• Allotrope (form) of carbon consisting of a single layer of carbon
atoms arranged in an hexagonal lattice
16. Summary
• Nanotechnology is multi disciplinary
• It is an enabling technology with great implications for the
society
• It offers exciting science and engineering challenges
• Expected to impact in all industry sectors
• Environmental, toxicological effects and ethical and ife cycle
issues need to be considered
17. • Nanoscience and technology is the branch of science that
studies systems and manipulates matter on atomic, molecular
and supramolecular scales (the nanometre scale).
• On such a length scale, quantum mechanical and surface
boundary effects become relevant, conferring properties on
materials that are not observable on larger, macroscopic
length scales.
• Plasmonics enables metal nanoparticles to act as antennas,
capturing light from around the particle with an optical cross-
section that is orders of magnitude larger than the physical
size of the particle. The strong localization of incident light
should make plasmonics ideal for enhancing photoconversion
in photovoltaics, photocatalysis and optoelectronic device.
18. Questions…
• Nanoscale materials therefore lie in a physical size regime
between bulk, macroscale, materials (the realm of condensed
matter physics) and molecular compounds (the realm of
traditional chemistry)
• How does one make a nanometer sized object?
• How do you make many (identical) nanometer sized objects?
• How do the optical and electrical properties of this nanoscale
object change with size?
• How does its optical and electrical properties change with its
“dimensionality”?
• How do charges behave in nanoscale objects?
• How does charge transport occur in these materials?
• Do these nanoscale materials posess new and previously
undiscovered properties?
• Are they useful?
19. Classification of nanomaterials
degrees of confinement
Due to reduction in the spatial
dimension, or confinement of
particles and basing upon the
dimensions
0D
1D2D3D (bulk) Quantum dots
Nanosphere
Nanocapsules
Fullerenes
Nanorods
Nanotubes
Nanowires
Nanobelts
Discs
Platelets
ultrathin films
super lattices
20. Properties change
mm nmμm
No change Physical laws and effects differ
Electronic
properties
Chemical
properties
Physical
properties
nm diameter is comparable to the characteristic length scales of
Elementary processes and is the scale at which nature operates
(DNA, virus, proteins)
Quantum size
effect
Single electron
tunneling
Macroscopic
quantum
tunneling
Microstructure,
Melting point,
Hardness,
Ductile ceramics
Interfaces and surface become very
important
22. • Metals have “full” conduction bands while semiconductors
and insulators have “empty” conduction bands.
• semiconductors and insulators there is anrange of energies
that cannot be populated by carriers separating the valence
band from the conduction band. This forbidden range of
energies (a no man’s land for electrons) is referred to as the
band gap
• All materials are composed of grains, which in turn comprise
many atoms. These grains can be visible or invisible to the
naked eye, depending on their size. Conventional materials
have grains varying in size anywhere from hundreds of
microns to centimeters.
• Carbon black is a nanomaterial that is used in car tyres to
increase the life of the tyre and provide the black colour.
24. Top-down Bottom-up
• Individual atoms and
molecules are placed or are
self-assembled precisely
where they are needed
• Can create new structures
Methods of nanostructure creation
• Successive cutting of a bulk
material to get nano sized
particle
• Silicon chips
• Photolithography
25. • Intrinsic properties of nanomaterials
are different from conventional
materials, since the majority of atoms
are in a different environment
• Substances with high surface areas
have enhanced chemical, mechanical,
optical and magnetic properties, and
this can be exploited for a variety of
structural and non-structural
applications
27. Medieval stained glass windows
are an example of how
nanotechnology was used in
the pre-modern era. (Courtesy:
NanoBioNet)
28. Outline
Number of sodium atoms in a spherical cluster of diameter d
Gold is known as a shiny, yellow noble metal that does not tarnish, has a face
centred cubic structure, is non-magnetic and melts at 1336 K. However, a small
sample of the same gold is quite different, providing it is tiny enough: 10 nm
particles absorb green light and thus appear red. The melting temperature
decreases dramatically as the size goes down. Moreover, gold ceases to be
noble, and 2–3 nm nanoparticles are excellent catalysts which also exhibit
considerable magnetism. At this size they are still metallic, but smaller ones turn
into insulators. Their equilibrium structure changes to icosahedral symmetry, or
they are even hollow or planar, depending on size