Nanoparticles

Nanoparticles are particles between 1 and 100 nanometres in size with a surrounding interfacial layer. They are the fundamental components in the broad field of nanotechnology. Nanoparticles exhibit a number of special properties relative to bulk material.

Definition

The term "nanoparticle" is not usually applied to individual molecules; it usually refers to inorganic materials. The reason for the discrepancy is that, although typical molecules are less than 1 nm in size, they are not often referred to as nanoparticles.

Properties

Nanoparticles are of great scientific interest as they are effectively a bridge between bulk materials and atomic or molecular structures. A bulk material should have constant physical properties regardless of its size, but at the nano-scale, this is often not the case. Size-dependent properties are observed such as quantum confinement in semiconductor particles, surface plasmon resonance in some metal particles and superparamagnetism in magnetic materials.

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 science, optical science, and electronics. They are also used in solar cells, catalysis, and as quantum dots in quantum computing.

Health and safety

The health impact of nanoparticles is currently a rapidly growing area of research. Because of their size, they can more readily be absorbed into the body, deeper into tissues and cells, and can pose potential risks.

See also

• Nanotechnology
• Nanomaterials
• Quantum dots
• Nanomedicine