Miracle Fabric “Never Gets Wet”
- 24 november 2008
Swiss chemists have developed a fabric with extreme water resistant properties – in fact, they claim it “never gets wet”. The polyester material is coated with millions of nanofiliments which trap water as spherical balls on top of the material. Tilting the fabric a mere 2 degrees horizontal will cause the suspended water to slide off like marbles. Unfortunately this miracle material didn’t hold up to a run through a washing machine, but nonetheless an interesting innovation.
New Scientist explains:
The secret to this incredible water resistance is the layer of silicone nanofilaments, which are highly chemically hydrophobic. The spiky structure of the 40-nanometre-wide filaments strengthens that effect, to create a coating that prevents water droplets from soaking through the coating to the polyester fibres underneath.
“The combination of the hydrophobic surface chemistry and the nanostructure of the coating results in the super-hydrophobic effect,” Seeger explained to New Scientist. “The water comes to rest on the top of the nanofilaments like a fakir sitting on a bed of nails,” he says.
A similar combination of water-repelling substances and tiny nanostructures is responsible for many natural examples of extreme water resistance, such as the surface of Lotus leaves.
The silicone nanofilaments also trap a layer of air between them, to create a permanent air layer. Similar layers – known as plastrons – are used by some insects and spiders to breathe underwater.
This fine layer of air ensures that water never comes into contact with the polyester fabric. It can be submerged in water for two months and still remain dry to the touch, says Seeger.