Prof. John Xin, Head and Chair Professor of PolyU’s Institute of Textiles and Clothing, his PhD graduate Dr Hengrui Yang and Dr Catarina Esteves at Eindhoven University of Technology in the Netherlands have developed a special surface modified cotton fabric by grafting a layer of polymer, PNIPAAm, to a common cotton fabric.

At low temperatures, the modified cotton has a sponge-like structure at microscopic level. Up to a temperature of 34°C, it is highly hydrophilic and can absorb 340 % of its own weight of water from misty air. When the environment temperature rises to 34°C or above, the material will become hydrophobic or water-repellant and its structure will become completely closed. Pure water absorbed at lower temperature will be released. This water absorbing and releasing cycle can be repeated many times. Details>>