Learn: Nanoparticles – What they are and why properties change

Welcome!Great to see you back! You've already learned about bonding, structures, and properties of materials. Today, we'll build on that knowledge by exploring nanoparticles and why their properties are different from larger materials.

What are nanoparticles?Nanoparticles are tiny particles with dimensions between 1 and 100 nanometres (nm). A nanometre is 1 billionth of a metre! They are much smaller than most materials but larger than individual atoms or molecules.

Why do nanoparticles behave differently?Nanoparticles have a high surface area to volume ratio. This means most of their atoms are on the surface, making them very reactive. Their small size also lets them interact with light, heat, and other substances differently than bulk materials.

Surface area to volume ratioThe surface area to volume ratio increases as particles get smaller. This means nanoparticles have more surface area available for reactions compared to larger particles of the same material.

Properties of nanoparticlesBecause of their size and surface area, nanoparticles can have unique properties such as increased strength, improved optical characteristics, and enhanced reactivity. These properties are useful in fields like medicine, electronics, and cosmetics.

Applications of nanoparticlesNanoparticles are used in many industries. For example, silver nanoparticles are used in antibacterial products, while titanium dioxide nanoparticles improve sunscreens by blocking UV rays. Nanoparticles can also be used in drug delivery systems to target specific cells in the body.

Risks of nanoparticlesWhile nanoparticles have many benefits, there are also risks. Their small size means they can enter cells and potentially cause damage. Scientists are still studying the long-term effects of exposure to nanoparticles on health and the environment.

Review Time!Great work! You've learned about nanoparticles, their unique properties, and their uses and risks. Let's test your understanding with a few final questions.