NANOSCIENCE AND NANO PARTICLES
Origin Of Nano
The origin of the the term “nano” comes from the Greek word “nanos” for dwarf, but in scientific usage, “nano” means one billionth.
One nanometer is 1/1000000000 of a meter.
Nano science is the study of fundamental principles of molecules and structures with at least one dimension roughly between 1 and 100 nanometers.
what exactly is nanotechnology?Most definitions revolve around the study and control of phenomena and materials at length scales below 100 nm and quite often they make a comparison with a human hair, which is about 80,000 nm wide.
It seems that a size limitation of nanotechnology to the 1-100 nm range, the area where size-dependant quantum effects come to bear, would exclude numerous materials and devices, especially in the pharmaceutical area, and some experts caution against a rigid definition based on a sub-100 nm size.
Another important criteria for the definition is the requirement that the nano-structure is man-made. Otherwise you would have to include every naturally formed biomolecule and material particle, in effect redefining much of chemistry and molecular biology as 'nanotechnology.'
So nanotechnology can be defined as “The design, characterization, production, and application of structures, devices, and systems by controlled manipulation of size and shape at the nanometer scale (atomic, molecular, and macromolecular scale) that produces structures, devices, and systems with at least one novel/superior characteristic or property.”
Nanotechnology is the manipulation of matter at the nanometer scale to create novel structures, devices and systems.
History of Nanotechnology
2000 Years Ago – Sulfide nanocrystals used by Greeks and Romans to dye hair.
1000 Years Ago (Middle Ages) – Gold nanoparticles of different sizes used to produce different colors in stained glass windows.
1974 – “Nanotechnology” - Taniguchi uses the term nanotechnology for the first time.
1981 – IBM develops Scanning Tunneling Microscope.
1991 – Carbon nanotube discovered by S. Iijima
• Carbon NanoTubes
• Information Technology
• Nano Robots
Stinger: Targeted Drug Delivery
Nanomaterials is a field which takes a materials science-based approach to nanotechnology. It studies materials with morphological features on the nanoscale, and especially those which have special properties stemming from their nanoscale dimensions.
Application of nanomaterials
Sunscreens and Cosmetics. Phosphors for High-Definition TV Elimination of Pollutants. High-Sensitivity Sensors.
University of Granada (Georgia Tech Photo: Gary Meek)
Nanoscale Approaches and Fabrication
Top-down Approaches Bottom-up Approaches
Top-Down and Bottom-Up Technique
In top down technique, generally a bulk material is taken and machined it to modify into desired shape and product.
On the other hand, bottom up technique is used to build something from the basic material.