The new aerogel makes water purification faster and cheaper

According to foreign media reports, it is possible to obtain pure, clean drinking water by converting liquid brine or polluted water into steam. Now, thanks to a newly developed material, that approach may become cheaper and easier. Invented by Shaobo Han, a postdoctoral student at Linkoping University in Sweden, the material is a cheap, porous aerogel made mostly of cellulose (and air), with the addition of an organic polymer called PEDOT:PSS.

Cellulose is the most abundant organic compound on earth and is the main component of plant cell walls. PEDOT:PSS on the other hand is very good at absorbing energy from sunlight - it is particularly adapted to the thermal infrared spectrum of sunlight.

To make a thin layer of aerogel float on contaminated or saltwater surfaces in a closed solar still, the researchers added a layer of porous foam to the bottom. Once in place, the gel absorbs water from below while absorbing solar energy from above. This causes the absorbed water to quickly heat up and turn into vapor, reportedly at a rate four to five times faster than the sun heats water directly.

The vapor then condenses onto a plate above the aerogel to form a pure liquid water droplet, which eventually drops into a collection tank. All salt or other impurities are left in the gel, which can be washed and reused many times.

"We hope and believe that our results will help millions of people who do not have access to clean water," noted Associate Professor Simone Fabiano, who led the study.

The research has been published in Advanced Sustainable Systems.