May 30, 2022 06:00:00

'Konjac' develops a new material that produces a large amount of water from desert air

Using

glucomannan , the main ingredient of konjac, a new material has been announced that can produce as much as 13 liters of water a day at a low price of only $ 2 per kg (about 250 yen).

Scalable super hygroscopic polymer films for sustainable moisture harvesting in arid environments | Nature Communications
https://www.nature.com/articles/s41467-022-30505-2

Low-Cost Gel Film Can Pluck Drinking Water From Desert Air --UT News
https://news.utexas.edu/2022/05/23/low-cost-gel-film-can-pluck-drinking-water-from-desert-air/

There are few areas with abundant water resources like Japan, and it is said that two-thirds of the world's population is affected by water shortages, albeit to a greater or lesser extent. Water purification technology can provide drinking water from seawater and contaminated water, but it is not suitable for areas such as desert areas where there is no existing water source in the first place.

Therefore, a research team of Youhong Guo and others, who are studying materials engineering at the University of Texas at Austin, used cellulose , which is a typical dietary fiber, and the main component of konjac to collect water contained in the atmosphere. I have developed a film made from a certain glucomannan.

The 'highly hygroscopic polymer film' developed by the research team is a cellulose that captures water with the open-hole structure of 'konjac gum' made of glucomannan and exhibits hydrophobicity, that is, water-repellent properties in response to heat. By using, it is a mechanism to take out the collected water easily and with low energy. With 1 kg of this film, it is possible to produce 6 liters of water a day even in dry areas with a relative humidity of less than 15%, and 13 liters of water in areas with 30% relative humidity.

Film can be manufactured from inexpensive materials, and it is easy to make by simply mixing the materials, pouring them into a mold, and then drying them.

The left is a schematic diagram of the device that collects water from the film, and the right is a photograph of the prototype. It is said that 70% of the absorbed water can be taken out just by heating the new material at a temperature of 60 degrees for 10 minutes. 'You don't need a degree to use it, it's easy enough to make at home with the ingredients,' Guo said.

Funded by the Defense Advanced Research Projects Agency (DARPA) of the US Department of Defense, the study focuses on supplying water to soldiers operating in dry climates, but because it is a simple technique. The research team believes that it will be commercially available at home centers.

'This study is about a practical solution that allows people to get water in the hottest and driest places on the planet, thereby stabilizing drinking water,' said Guihua Yu, co-author of the paper. Many people who don't get it may be able to put a device that produces water at home with a simple operation. '