Ever strolled into an outfit store and picked out a pair of khaki trousers from a rack that has a big red poster hanging from it with three simple words printed on it: “Stain-Repellent Fabric”? And you go thinking, “Yeah right!”
All of us have gone through the unpleasant experience of dropping drinks and foods on our clothes before and watching in distress at the giant stain that appears soon after. So, how can fabric be stain-repellent? It must simply be a marketing stunt? Incorrect. Welcome to the realm of nanotechnology.
On a basic level, nanotechnology is the manipulation of molecules in order to build structures starting from the molecular state. When working with nanotechnology, scientists work with structures from 1 nanometer to 100 nanometers. In order to understand how small that actually is, you can see below that a red blood cell is approximately 7000 nanometers across.
Now, imagine working with particles seven hundred to seven THOUSAND times smaller – and we all have trouble putting a thread through the eye of a needle!
So how does the concept of nanotechnology have anything to do with stain-repellent fabrics? Working with structures so small allows textile manufacturers like Nano-Tex, to work with nano-sized particles and fibers that further enhance the quality of the fabrics. By using nano-sized fibers, also known as nanowhiskers, these manufacturers are able “to pack extra atoms” into the fabric atoms, which help repel liquids spilt on the surface of the fabrics. Thus, the fabric is almost invulnerable to liquid as the tightly packed atoms cause the liquid to bead up and slide off the fabric rather than soak into the fabric.
In this picture, red kool-aid is poured onto a pair of trousers and you can see that instead of soaking up into the fabric, the liquid is beading up.
In order to embed the nanowhiskers into the fabric, as shown in the picture, the fabric is submerged into water filled with billions of nanowhiskers. As the water is heated and evaporated, the nanowhiskers bond chemically with the fabric. The nanowhiskers make the fabric hydrophobic, i.e. water-hating. Therefore, the implanting of nanowhiskers prevents the water from soaking into the fabric, and instead they act like “the fuzz on a kiwi” and create a cushion of air around the fabric, causing the liquid to bead up (due to surface tension of the liquid droplet) and roll off. Unfortunately, the chemical makeup of nanowhiskers is unavailable in the public domain and thus, it is not possible to demonstrate the bonding of cotton fabric (cellulose) to nanowhiskers.
So, it turns out that “stain-repellent” clothes are not just a marketing gimmick, but rather cutting-edge technology. However, nanotechnology is not limited to consumer-based products only. Research is ongoing in the field of medicine to produce delivery systems that can pinpoint and destroy viruses and cancers with laser-like accuracy rather than the collateral damage of chemotherapy today. In addition, work is ongoing to produce light-weight carbon materials many hundred times stronger than steel among other applications.
As nanotechnology advances, there are several unanswered questions. What is nanotechnology: 1nm to 100nm or just up to two-tenths of a nanometer? How long will it take before nanotechnology is useful from the mainstream perspective? Are we aware of all the possible deleterious effects of nanotechnology (stain-repellent fabrics), and are there any regulations to protect us from the same? One of the areas of research is increasing the human lifespan – will this be available to all or a prerogative of the rich only?
1. ” Introduction to Nanotechnology.” Nanotechnology Made Clear. Web. 17 Oct. 2010.
2. “Nano-particles & Their Uses in Textiles | Processing, Dyeing & Finishing | Features | The
ITJ.” The Indian Textile Journal – Technology & Trade Info for Tomorrows Textile
Industry. Web. 17 Oct. 2010.
3. NanoSense. Web. 17 Oct. 2010. <http://nanosense.org/>.
4. Home. Web. 17 Oct. 2010. <http://www.bekaerttextiles.com/>.