Trapping water from desert fog

A coated cotton fabric can absorb more than 3 times its weight in water from warm, moist air, and release it again at higher temperatures. John Xin at the Hong Kong Polytechnic University in China, Catarina Esteves at Eindhoven University of Technology in the Netherlands and their colleagues grafted a temperature-sensitive polymer onto cotton fabric. At 16–25 °C, the polymer chains interact to form a porous, sponge-like network that traps water. At higher temperatures, the material shrinks and releases its moisture in a cycle that is reversible. The material could be useful in dry, desert areas to collect water from morning dew or fog, the authors say. Adv. Mater. http://dx.doi.org/10.1002/adma.201204278 (2013)