Silver nanotechnology is revolutionizing electronics and healthcare, but it also raises environmental and health risks. Whether these technologies will bring positive change to humanity, or create new challenges, needs to be debated.
The word “nano” is everywhere these days. Nanotechnology has been applied in a wide variety of fields, and it has penetrated into our daily lives. From smartphones to cosmetics to medical devices, nanotechnology is everywhere. But what does it all mean, and how is it changing our lives?
The word nano comes from the ancient Greek word “nanos,” which means “dwarf. A nanometer, or nanometer, is one billionth of a billionth of a meter long, and is so small that it is invisible to the eye. Nanotechnology is the art of synthesizing, assembling, and controlling materials at these extremely small scales, as well as the scientific methodology for characterizing and measuring their properties. As a branch of advanced science, it is an important foundation for modern technological advancements. As such, nanotechnology has made possible many innovative products that were not possible in the past. The possibilities of nanotechnology are endless and are being experimented with and applied in many fields.
Especially for metals like gold and silver, it is technically very difficult to process them at the nanoscale. The atoms of these metals are very strongly bonded to each other and tend to clump together when processed at the nanoscale. Gold and silver as we know them are known for their ductility (flexibility) and malleability (the ability to stretch easily), but when they are shrunk to the nanoscale, their properties change dramatically. For example, in the case of silver, it has been observed that when thin silver foil is made, the silver atoms have a strong tendency to clump together when the thickness is reduced to 100 nanometers (nm) or less, causing the silver foil to fold into a pucker rather than stretch. This is one of the reasons why silver is not used much in practice due to its difficulty in processing, despite its potential for use in electronic components due to its superior electrical and thermal conductivity to copper.
However, these properties of silver are opening up new possibilities for various nanotechnologies. For example, when silver becomes nanoparticles, its properties change in a completely different way. Silver nanoparticles have strong sterilizing properties, which has led to the development of washing machines and water purification devices. In particular, washing machines using silver nanoparticles are attracting attention because they can effectively remove bacteria. While traditional silver is resistant to oxidation and does not have the ability to kill bacteria, silver nanoparticles react well with the surrounding substances thanks to their size and have the ability to destroy bacteria.
The representative silver nanoparticle washing machines in Korea are divided into S, L, and D products. Company S uses an electric current inside the washing machine to generate silver ions, which eliminate bacteria. Company L, on the other hand, coats the inside of the washing machine with silver nanoparticles to achieve antibacterial effects, and Company D achieves a similar effect by mixing silver powder in the washing tank itself.
There are three scientific explanations for the antibacterial activity of silver nanoparticles. First, silver nanoparticles damage the cell membranes of bacteria, making it harder for them to survive. Second, silver acts as a catalyst to accelerate the aging of bacteria. Third, the silver nanoparticles are similar to the size of the bacteria’s food, so when the bacteria ingest them, it causes metabolic disturbances that eventually lead to death.
However, despite this innovative technology, in 2006, the U.S. Environmental Protection Agency (EPA) banned the export of silver nanoparticle washing machines from Korea’s S Company. This was due to concerns that silver nanoparticles could be harmful to humans. The reasoning was that silver nanoparticles were classified as a disinfectant and were not sufficiently tested for possible side effects when they come into contact with the human body or spread in the environment. This means that consumers need to be more cautious when using silver nanowashers.
Unlike the properties of ordinary silver, silver nanoparticles have very unique properties. Research into the properties of nanoparticles is still ongoing, and the debate about whether they are beneficial or harmful to humans and the environment will continue. Based on these findings, we can expect silver nanotechnology to become safer in the future, but we should also be wary of the potential dangers of nanotechnology.
