What is nanotechnology?
Nanotechnology is a multidisciplinary branch on engineering involving study of materials at a length scale of 1-100 nm. One nanometer is a billionth of nanometer. For reference, a sheet of paper is 100 thousand times thicker than a nm and a human hair is 70 thousand times thicker than a nm. Nanotechnology involves synthesis, imaging, modeling, and manipulating materials at this length scale. The materials properties at this length scale are very different than the bulk scale properties of materials. The difference between bulk properties and nanoscale properties is due to the different nature of physics theories. At nanoscale the quantum effects govern the properties of the materials unlike at the bulk scale where classical mechanics govern the behavior of material properties. Because of this difference, the materials designed using nanotechnology demonstrate unprecedented properties and scientist are taking advantage of nanoscale phenomena to bring useful and innovative applications.
Carbon nanotubes are one of the most researched nanomaterials because of their excellent mechanical, electrical and thermal properties. It consists of carbon atoms covalently bonded in a cylindrical crystalline lattice. A single wall carbon nanotube consists one cylinder of carbon atoms while multiwall carbon nanotubes have many concentric cylindrical lattices of carbon atoms. Single walled carbon nanotubes (SWCNTs) are much lighter yet many times stronger than steel making them the strongest known material. The Young’s modulus of SWCNTs is in order of 1 TPa, where as carbon fibers have 800 GPa and glass fibers have 70 GPa. CNTs have average breaking strength of 30 GPA whereas carbon fiber about 6 GPa and high strength steel about 3 GPa. Continue reading