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Nanotechnology SUWARNA DATAR| AP 608
Whats going on at nanoscale?
What is unique about this size?
At nanoscale the most fundamental properties of materials depend
on their size which is not true in microscale
Eg. Nnaoscale circuit may not obey Ohm’s law.
This coupling of size with the most fundamental chemical, electrical
and physical properties of materials is the key to nanosceince
What happens when we reduce
the size? Imagine cube of gold with 91.4 cm each side
Produce 8 little cubes from this 50 cm on each side
Properties of each small cube are same as the big
one
Go on reducing this size from 50 cm to 25 cm to
mm to µm, gold will have the same properties
But at nanoscale all the properties like colour,
melting point, chemical properties changes
For every size the colour would be different
History
Every once in a while anything new which is discovered changes
everything
Smaller, lighter, faster and smarter
became the anthem
Nanotechnology now promises to give is everything:
Faster and tinier computers
Better tennis balls
Stain resistant clothing
Transparent sunscreen
Molecular sensors
Cell specific cancer therapy
Plenty of room at the bottom
Scanning Probe Microscopy
1981 1989
Fullerene
The C60 molecule, is 0.7 nm in diameter and,
just like a soccer ball, consists of 20 six-
membered and 12 five-membered rings
In chemistry there is no other molecule which is
formed by same atom and which is as big as
Fullerene
What is Nanoscience &
Nanotechnology
Nanosceince: Study of fundamental principles of molecules and
structures with atleast one dimension roughly between 1 and 100
nm.
Nanotechnology: Applications of these structures into useful devices.
Why is it unique?
Because at this size the regular properties of materials like conductivity,
hardness, melting point etc changes
Emerging Technologies
Fast burning rocket fuel additives
Targeted drug delivery
Detectors for biotoxins
Emerging Technologies
Course structure Introduction : Concept of Length Scales, Definition of Nanotechnology and Nanoscience, Basic
Concepts- Size Effects on Properties, Top Down vs Bottom Up, History of Nanotechnology
Background preparation: Physical Chemistry of solid surfaces, crystal structures, surface energy, chemical potential, Fundamentals of nucleation and growth, Electrostatic Stabilization Surface charge density, Electric potential at the proximity of solid surface, Van der Waals attraction potential, Interactions between two particles: DLVO theory, Solvent and polymer, Interactions between polymer layers, Mixed steric and electric interactions.
Characteristic scale for Nanoscale Phenomenon phenomena: Nanoparticles, nano-clusters, nanotubes, nanowires and nanodots. Electronic structure: quantum dots, quantum wires and quantum wells, confinement of electrons energy quantization semiconductor nanocrystals, carbon nanotubes, quantum wells.
Characterization and properties of nanomaterials: Structural Characterization, X-ray diffraction (XRD), Small angle X-ray scattering (SAXS), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Scanning probe microscopy (SPM), Surface plasmon resonance, Quantum size effects, Surface scattering, Change of electronic structure, Quantum transport, Effect of microstructure, Ferroelectrics and dielectrics, Superparamagnetism.
Applications of Nanomaterials: Molecular Electronics and Nanoelectronics, Biological Applications of Nanoparticles, Catalysis by Gold Nanoparticles, Band Gap Engineered Quantum Devices, Quantum well devices, Quantum dot devices, Nanomechanics, Carbon Nanotube Emitters, Photoelectrochemical Cells.