Nanomaterials have now been around for decades and they have found their way into ordinary products such as foods, cosmetics, sunscreen and sportswear. Why did ‘nano’ become so popular? And what risks are involved when getting exposed to these nanoengineered entities?
Pros and cons with nanosized materials
The nanoscale is beyond what we can perceive with our bare eyes. The wavelength of visible light is in the range 400 – 700 nm, and the nanoscale is quite a bit smaller, traditionally defined as the size range 1 – 100 nm. A fascinating aspect with things this small is that material properties start to change, and even new ones could appear. The reason for this transformation is that as an object gets smaller, the surface to volume ratio increases which makes the surface properties dominant over the bulk ones. Since surface atoms generally are more reactive than the ones in the bulk, the properties of a material at the nanoscale could be very different from the properties of the same material in a larger chunk. For example, the melting temperature of gold decreases hundreds of degrees as the size of a gold particle is reduced from the macroscale to the nanoscale. If made sufficiently small, it can even melt at room temperature.
Understandably, nanotechnology has received much attention, and nanomaterial properties and potential areas of usage have been much explored. There is however another side of the coin. The nanoscale is the size range of the molecules in our bodies, and in this context, what was previously considered attractive properties are now rather the opposite. Being so small, nanomaterials could enter our bodies, for example via inhalation, ingestion or penetration of the skin, where they then could interact with e.g. proteins and cells. Such scenarios are not always well-studied, which means that nanomaterial exposure could constitute a risk for human- and other living creatures’ health.
Science on surfaces – a bigger perspective on the small
Learn more about the opportunities and safety-challenges of nanotechnology by listening to our podcast, Science on surfaces - a bigger perspective on the small. In this episode, we talk more about what makes nanotechnology so extremely attractive, what risks that are involved, and what unexplored opportunities there are for the future.