Strolling in the sun may soon become a favourite winter activity among people thanks to Australian researchers who have developed woollen clothing which not only changes its colour, but also protects against harmful effects of ultraviolet (UV) rays.
Tong Cheng, a doctorate student from Deakin University, says that the clothing can change its colour in the sun in just two to three seconds, and this swiftness ensures speedy protection from harmful radiations coming from the star.
"Initial tests have shown these rays are almost totally blocked," ABC Science quoted Tong Cheng, a doctorate student from Deakin University, as saying.
Although the colour-changing cotton and glass were already in existence, this is the first time that such photochromatic technology has been applied to wool.
Cheng, who has developed a type of silica polymer called silica sol, says that it has many nanopores that help it trap the pigment of the photocromatic dye. When the dyed fabric is exposed to sunlight, the dye molecules change structure, which in turn results in a change in the appearance of the dyed wool.
"Tong Cheng had to ensure that the pores in the polymer were just the right size. If they were too large for example, the dye would seep out," said supervising researcher Dr Rex Brady.
So far, the researchers have developed white fabric, which changes its colour to blue or red.
According to Cheng, the treated wool product looks and feels like other wool products.
"It is impossible to notice the difference between normal wool fabric and fabric coated with the polymer. The fabric maintains its softness and drape and the colour is preserved when washed," she says.
She believes that the technology has the potential for both novelty fashion and function in the future.
Cheng is now planning to develop woollen t-shirts that only reveal their patterns when worn outside or under certain lighting.