Nanoparticles

Essentials

Nanoparticles are particles that contain between 1 and 1000 atoms arranged in a specific manner. They have diameters between 1 and 100 nanometres.
As a result of their tiny size, nanoparticles have a larger surface area to volume ratio compared to larger particles. This provides them with unique properties.
They exist naturally in the world, but can also be engineered for use in various science and technology fields – a concept known as nanotechnology.

Properties of Nanoparticles

Due to the increased surface area to volume ratio, nanoparticles exhibit higher reactivity compared to other particles.
Nanoparticles often show different optical, electrical or magnetic behaviour compared to larger particles of the same material. This is due to the behaviour of electrons within nanoparticles.
They can also conduct electricity and heat better than their bulk material.
Nanoparticles tend to be highly reactive, to a degree that often depends on their exact size and shape.

Uses and Applications of Nanoparticles

Nanoparticles have a wide array of applications, such as in medicine, electronics, textiles, cosmetics, and materials science.
In medicine, nanoparticles can be used for drug delivery, enabling specific targeting of cancer cells.
In electronics, they can be used to create more efficient and powerful devices. Quantum dots are a notable type of nanoparticle used in screens for brighter and more vibrant displays.
In cosmetics, nanoparticles of titanium dioxide and zinc oxide can be used as sunscreens, because they are not visible on the skin but still absorb and reflect UV light.
In materials science, nanocomposites, which incorporate nanoparticles into a bulk material, can result in improved hardness, toughness, and other properties.

Potential Risks and Concerns with Nanoparticles

As nanoparticles can be easily inhaled or absorbed, there are concerns about potential health risks. Studies are ongoing to evaluate these risks.
The environmental impact of nanoparticles is also under scrutiny. Their tiny size and high reactivity could potentially lead to negative effects.
Transparent sunscreens, for example, make use of titanium dioxide nanoparticles. When these wash off into the water, they may harm aquatic life.
Many aspects of nanoparticles, including their behaviour, impact, and safe handling, are still subjects of active research.