We are well into autumn now, and when it comes to weather there’s one thing you can be certain of in Britain (besides the cold) – rain. Woe betides those who leave home without waterproofs and umbrellas. Even with such paraphernalia you might still get wet if the downpour is heavy enough – there’s only so much water a brolly can take.
Not so with a new waterproof material developed in Switzerland. Researchers at the University of Zurich have come up with a new type of fabric made from fibres of polyester that are coated in millions of minuscule silicone fragments. It’s the most water-repellent material suitable for making clothes ever produced.
Lead researcher Stefan Seeger took their inspiration from examples in nature, such as the surface of Lotus leaves. These biological water-repellents have a particular nanostructure that the new material emulates. Silicone nanofilaments, just 40 nanometres wide, coat the polyester and stop water seeping through.
They also trap a small layer of air that means water never even comes into contact with the underlying polyester. In a demonstration of hydrophobic power, the material was submerged underwater. When it was removed two months later, it was still dry to the touch. Seeger spoke to New Scientist about his creation:
“The combination of the hydrophobic surface chemistry and the nanostructure of the coating results in the super-hydrophobic effect,
“The water comes to rest on the top of the nanofilaments like a fakir sitting on a bed of nails,” he says.
It’s not just polyester that can be protected in this way, although it currently gives the best results. The silicone coating can also be applied to other materials such as wool and cotton. It could even lead to the invention of self-cleaning clothes!