All physical and chemical properties are size dependent, and the properties of materials on the nanosize scale have important consequences in wide ranging fields. Exploiting nanoscale behavior will eventually lead scientists to develop devices that can selectively attack diseased cells, increase computer speed or improve chemical and biological sensors. The composition, size, shape and environment of nanosized particles strongly influence their ultimate utility. Chemical dyes were the first use of metal nanoparticles, dating back hundreds of years. Glass blowers used gold and silver colloids as the coloring agents in stained glass windows. Gold nanoparticles (having a size of 10 -15 nm) produce a red or purple hue while silver nanoparticles (with a size of 20 -30 nm) produce a yellow hue. Another very important field leading the development of nanotechnology is catalysis where nanosized materials composed either of transition metals like platinum or metal oxides often facilitate chemical processes by increasing the rate of the reaction. By making catalyst particles very small, large surface areas are achieved with a small volume of material. In the field of medicine, biological and chemical sensors are made of nanoscale particles that are very sensitive to their local environment, making them ideal for detection of trace amounts of many substances, including bacteria, DNA and environmental toxins. The electronics industry is focused on using nanoparticles in data storage devices, which are dependent on the number of memory elements that can be packed into a given area. By making features that are very small, more information can be encoded into a given area increasing computer speed.
Department of Chemistry - NorthwesternUniversity