What is nanoscience?
The word 'nano' refers to numbers on a mind bogglingly small scale, that is represented as 10*(-9) metres in scientific parlance. That would be 0.000000001 metres. Nanoscience is the controlled synthesis, study and possible applications (nanotechnology) of materials - either inidividual particles or their assemblies whose sizes are of this magnitude.Why nano?
Nanotechnology, nanoscience and novel materials are the craze these days. Let us see why.
The behaviour of objects change dramatically as their sizes decrease beyond a certain level. This is the weird quantum world whose denizens are reputed for their quirky behaviour. So what is happening. Any object can be broken down into smaller and smaller parts until we reach the atomic stage. For nanoscience we don't quite have to go to that level all the time but let us look at that situation now. The particles that make up an object behave in quite a different fashion compared to the object itself. For our convenience we can imagine it to be a sort of an averaging of all the individual behaviour of the atoms which in the end turns out to be quite different from that of it's constituents. This means that we can use the nanoparticles of a substance for a specific process, say to catalyse a particular reaction, that would normally not be possible to use as such.
This is because the nanoparticles of that substance behave in a different fashion compared to the object itself. So if we can synthesize the required nanoparticles at will we can achieve a whole lot of things that would normally be difficult or impossible to do. Nanostructures
Nanoparticles can also be be made to assemble/self assemble in a specific fashion into structures (nanostructures) that have special properties. For example nanowires, which are basically one dimensional 'wire-like' materials that are either deposited on a surface or are attached to a surface from one end can exhibit conducting properties that are different from normal wires. Nanowires have been used as gas sensing devices that can detect toxic gas leaks in small quantities otherwise difficult to detect easily.Behaviour as a function of structure.
The structure of a nanomaterial can determine it's specific behaviour. Different structures made of the same material can have different properties. A very exciting class of nanostructures includes those made out of semiconductimg oxides like Zinc oxide (ZnO) for example. ZnO can exhibit a remarkable variety of structures ranging from nanorods, wires, springs, belts, propellors, loops etc. Exciting work in this field is being done by Dr. Zhong Lin Wang, director of Georgia Tech's Center for Nanoscience and Nanotechnology, Atlanta