We're all used to water-repellent materials nowadays, and it's no surprise to see droplets running off special cloth without wetting it. The technology has, however, only worked for cold water. Until now, thanks to nanotechnology.
Materials known as super-hydrophobic are often inspired by ideas found in nature—using a combination of waxy coatings and air bubble-trapping spikes it's proved possible to create cloth that repels water that's even sprayed onto it by force. But high temperature water tends to degrade both repellent capabilities by softening the waxes and heating the air pockets so they disappear, and that then allows incoming water droplets to physically wet the surface of the material, and then to soak through and wet the wearer underneath
Now a team at the University of Minnesota, working in collaboration with Hong Kong Polytechnic University have advanced the science a huge step by rethinking how hydrophobic materials are constructed. They used a teflon material, already known to be water and oil-repellent, and mixed in carbon nanotubes. These last have recently been explored for their inherent hydrophobia that apparently even works with hot water. In combination the two create a material that's highly water-repellent, with air bubble-trapping dimples created by the carbon nanotubes that aid its power. And, best of all, it does a fantastic job of repelling scalding water.
Why is it so important to deal with this problem? Because scalding water injuries may be more common than you think, and they can be devastating and dangerous particularly for the young or elderly. If this new nanotech waterproofing were incorporated into clothing or even cooking mitts, the potential for scald prevention would be very high indeed. To that end the research team is perfecting the material to improve its flexibility and color.
[via New Scientist]