Nanotechnology means technology at the nanometer scale that is measured in billionth of a meter. Nanotechnology is a powerful tool for precise positioning of atoms and molecules. It allows construction of a wide range of artifacts where components may be measured in nanometres.
Categories of Nanomaterials
Nanomaterials may be classified into the following categories:
• Nanofibres and Nanotubes
• Nanocrystalline alloys
• Nanocrystalline solids
Submicron or ultra micron size particles available as high performance magnetic recording materials, magnetic fluid materials, randiant resistant materials, packaging materials and solar battery material.
Nanofibres and Nanotubes
Nanometer size long linear material, microconductors, microfibres, optical materials, nanotubes of PTFE, PET, PEEK (10 nm dia).
Films used as gas catalyst materials.
Nanometer crystalline grain materials made by high precision forming nanoparticles or controlled crystallization.
Alloys that have a majority of grain diameters in the typical range from 1 to 50 nm.
Composite materials which utilize nanoscale reinforcements instead of conventional particulates or fibres. Example: SiCp(Al) nanocomposite.
They are polycrystals the size of which is 1-10 nm so that 50% or more of the solid consists of inherent interface between crystals of different orientation. Clusters formed by homogeneous nucleation and grow by coalescence and incorporation of atoms. They display properties different from both the smaller atoms or molecules and the larger bulk materials.
Nanocrystalline materials have been synthesized by several techniques such as inert gas condensating, electrodeposition, sputtering and mechanical attrition.