nanoparticle

A nanoparticle is usually defined as a particle between 1 and 100 nanometers in size. To put that in perspective, a human hair is about 80,000 to 100,000 nanometers wide. Because these particles are so small and have a lot of surface compared with their volume, they can show physical, chemical, and biological properties that are different from those of the same material in a larger form. It is like taking a piece of gold and shrinking it so much that it can look red instead of yellow. Its behavior changes because of its size.

The term is not limited to one kind of material. These particles can be made from metals, ceramics, polymers, carbon-based materials, or semiconductors. That is one reason they are useful in many different fields.

You can find them in many places: in sunscreen, where very small zinc oxide or titanium dioxide particles help block UV rays; in electronics, where they can improve performance; in medicine, where they can carry drugs to certain parts of the body; and in environmental cleanup, where they can help remove pollutants from water or soil. Scientists are still finding new ways to use them.

The study and use of nanoparticles is part of nanotechnology, a growing field that may change many parts of daily life. So when you hear about new materials or new medical tools, the science behind them may depend on something extremely small.