London, Feb 12 : If you hate washing your woollens and silks, hate spending bucks on dry-cleaning, this might just be the news for you- self cleaning forms of wool and silk have been developed by researchers in Australia and China with the help of nanotechnology.
Dr Walid Daoud of Monash University, Victoria, Australia, and colleagues have stated that wool socks, skirts and silk ties may soon be cleaning themselves of smells and stains just in the sunshine. The secret behind this unique property of these clothes is a nano particle coating.
Such coating is already used to keep windows clear leading to "self-cleaning" versions of wool and silk fabrics.
As wool and silk are composed of natural proteins called keratins, they are considered to be the most prized and widely used fabrics in the clothing industry. But keeping these materials clean proves to be quite difficult as they are easily damaged by conventional cleaning agents.
For this new study, the researchers prepared wool fabrics with and without a nanoparticle coating - particles around five nanometres across (five billionths of a metre) composed of anatase titanium dioxide, a substance already used as a pigment that is known to break down and destroy contaminants upon exposure to sunlight.
"The self-cleaning technology in our work uses titanium dioxide photocatalyst that when triggered by light, it decomposes dirt, stains, harmful microorganisms and so on," The Telegraph quoted Dr Daoud, as saying.
Later, the fabric samples were stained with red wine and it was found that after 20 hours of exposure to simulated sunlight, the coated fabric did not show any signs of the red stain, on the other hand, the untreated fabric remained deeply stained.
The researchers said that the coating, which is non-toxic, can be permanently merged to the fibre and does not alter its texture and feel, thus retaining the silkiness of the silk tie. However, the tricky part in the research was to find a way to bind the keratin to the titanium dioxide,
"Applying a ceramic inorganic material to organic fibres, in particular keratin protein fibres such as wool, silk, hemp, and spider silk, remained a challenge," said Dr Daoud.
The researchers noted that that a chemical reaction to "activate" the surface of the fibres, may make the titanium dioxide crystals stick.
Dr Daoud said that the self-cleaning socks could be on the market as soon as the technology gets the technical and economical approval.
"It is anticipated that as soon as the technology receives the approval technically and economically, you will then be able to see the product in the market. Currently, industrial testing and mill trials of this patent-pending technology are being conducted," he said.
He added: "I believe that self-cleaning property will become a standard feature of future textile and other commonly used materials to maintain hygiene and prevent the spreading of pathogenic infection. Particularly since pathogenic microorganisms can survive on textile surfaces for up to three months.
"Self-cleaning technology can also help in reducing the consumption of chemicals, such as detergents and dry-cleaning solvents, water, and energy."
The study is scheduled for publication in the journal Chemistry of Materials.