Polymer coating allows cotton to harvest water from foggy desert air EINDHOVEN, Netherlands, Jan. 22 (UPI) -- Cotton with a special coating that collects water from fog is a potential solution to provide water in desert regions, Dutch researchers say. Scientists at Eindhoven University of Technology, working with researchers at the Hong Kong Polytechnic University, have developed a special polymer treatment for cotton fabric that allows the cotton to absorb exceptional amounts of water from misty air, as much as 340 percent of its own weight compared to only 18 percent without the coating. The coated cotton then releases the collected water as it gets warmer, they said. Up to a temperature of 93 degrees it is highly hydrophilic, meaning it absorbs water strongly, but once hotter than that it becomes hydrophobic or water-repellant and releases all the absorbed water, which is totally pure. This cycle of collecting and releasing water from misty environments as the temperature changes throughout the day can be repeated many times, the researchers said. The material may potentially be suitable for providing water in deserts where the air is often misty or foggy at night, they said.