Nanoparticle

Nanoparticles are particles between 1 and 100 nanometres (nm) in size with a surrounding interfacial layer. The interfacial layer is an integral part of nanoscale particles, and it often includes ions, inorganic and organic molecules. Molecules of this layer can be attached to the nanoparticle core, be free in the solution, or can form a structure that includes both.

History

The history of nanoparticles dates back to the use of colloidal gold nanoparticles by ancient civilizations for vibrant colors in pottery and glass. However, the scientific study of nanoparticles began with a lecture by Michael Faraday on the synthesis of gold nanoparticles in 1857.

Properties

Nanoparticles exhibit a number of special properties relative to bulk material. For example, the bending of solid materials, plastic deformation, is size-dependent in nanoparticles. Those exceptional properties are due to the large surface area of the particles compared with their volume, and to the high proportion of atoms at the surface.

Synthesis

There are several methods for creating nanoparticles, including gas condensation, attrition, chemical precipitation, ion implantation, pyrolysis and hydrothermal synthesis.

Applications

Nanoparticles have a wide variety of potential applications in the fields of biomedical, optical, and electronic fields. They have unique optical properties as they can absorb and emit light of wavelengths much larger than the particles themselves.

Health and safety

The health impact of nanoparticles is not fully understood, and there is ongoing research to explore the possible effects. Some nanoparticles can be toxic to humans and the environment, and their small size allows them to penetrate most physical barriers in organisms.

See also

• Nanotechnology
• Nanomaterials
• Quantum dot
• Gold nanoparticle

References

Nanoparticle Resources
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