There’s new hope for gymn socks, and it’s coming from Japan. If your clothes have a tendency to smell like Godzilla after wading through downtown skyscrapers all day long, Tokyo has the answer. Scientists from the University of Tokyo have created a long-lasting deodorant that is applied to one’s clothes, rather than one’s armpits.
Silver (symbol: Ag in the Periodic Table of the Elements) like Copper (symbol: Cu) has antimicrobial properties: it kills bacteria cold dead on contact, and as we all know, bacteria is the cause of body odor (BO). This factoid could have been put to practical use years ago but for one problem: there was no known (and reasonably cost-effective) way of making the silver stick to fabric, where it would be held against the wearer’s skin.
Enter Joseph Richardson, postdoctoral fellow at the University of Tokyo Graduate School of Engineering. His young son was eating chocolate one fine day in Japan, and managed to stain his shirt with the sweet candy. Richardson tried in vain to get the chocolate stain out. He failed, but the vexing problem got Richardson thinking. Chocolate, like red wine, contains a polyphenol known as tannic acid (TA), which is notorious for causing impossibly stubborn stains. The research team found a clear TA that causes no discoloration to fabrics, unlike the TA in chocolate and red wine, but does stubbornly attach itself to fabrics.
Richardson and the research team developed a coating out of a mixture of silver and tannic acid that they whimsically call ‘Ag/TA’, where tannic acid binds silver to the fabric. The coating can be applied to new clothing at the factory, or by the consumer at home, and is said to stay on clothing for at least 10 washes or more, while safely killing bacteria all the while. (Silver and polyphenols are both well-known to be completely safe in or on the human body.)
The coating is already being marketed and sold in Japan under the brand name ‘Swiff’, at an attractive price. If successful there, it surely will find its way here. Not that any of this matters in the long run: humans might be slowly losing their sense of smell.
