Nanochemistry is a branch of nanoscience dealing with synthesis, characterisation and applications of nanomaterials. Various chemical and physical techniques are used to manipulate atoms and molecules ranging in size between 1-100nm. These are used as building blocks to form nanomaterials, nanostructures, nanobots and nanoassemblies. When these are coupled with biological materials such as neurons or electronics or computers exciting new possibilities and applications emerge. Chemical reactions can be used to assemble atoms in molecular structures and physical techniques are employed to manipulate and position atoms for specific applications. Novel chemical synthesis can be used to make nanoscale structures used for building blocks with the desired shapes, surface area, structure, composition and size. The nanoscale feature endows unique structural and optical properties for use in catalysis, electro-optical devices and nanocarrier systems for drug delivery.There are many naturally occuring nanoassemblies such as liposomes, polypeptide miscelles etc. Nanomaterials exhibit properties that are distinct to those of bulk materials and have important applications such as sunscreens to block harmful UV light from the sun and catalysts with an unusually large surface area to speed up chemical reactions in industrial production of important compounds and medical products.
One of the most popular nanomaterial is the carbon nanotube. These have 1/6th the weight of steel but much stronger. Other materials may also form nanotubes. They can be excellent insulators or conduct electricity better than copper used in semiconductor devices. TiO2 is commonly used in self cleaning windows and ovens.