NANO IN MATERIEALS

In materials, things start to behave differently at the nanoscale. The bulk materials that we have traditionally dealt with are uncontrolled and disordered at small scales. The strongest alloys are still made of crystals the size and shape of which we control only crudely. By comparison, a tiny, hollow tube of carbon atoms, called a carbon nanotube, can be perfectly formed, is remarkably strong, and has some interesting and useful electrical and thermal properties. When particles get small enough (and qualify as nanoparticles), their mechanical properties change, and the way light and other electromagnetic radiation is affected by them changes (visible light wavelengths are on the order of a few hundred nanometers). Using nanoparticles in composite materials can enhance their strength and/or reduce weight, increase chemical and heat resistance and change the interaction with light and other radiation. Coatings made from nanoparticles can be unusually tough or slippery, or exhibit unusual properties, such as changing colour when a current is applied or cleaning themselves when it rains.