Specially Treated Cotton Can Harvest Water From Fog
The cotton is coated with a polymer known as PNIPAAm, which allows it to absorb 340% of its weight in fog droplets.
‘Fog harvesting’ for water isn’t a new technique. People use netting to capture fog droplets, which are then collected in a container. The process is hardly efficient, but thanks to a special treatment for cotton, it may become a viable solution for obtaining water in desert regions.
Researchers from the Eindhoven University of Technology and the Hong Kong Polytechnic University have developed a coating that allows the cotton to absorb high amounts of water from misty air. The cotton is treated with a polymer known as PNIPAAm, which allows it to absorb 340% of its weight, compared to only 18% without the coating. It has a sponge-like structure at temperatures up to 34°c and is highly hydrophilic.