On July 2, TASS reported that Chinese researchers have developed a porous aerogel-based material capable of actively absorbing water molecules while rejecting salt and other compounds in seawater or brine. The findings were published in ACS Energy Letters. Scientists say this enables the production of clean drinking water in hot, arid regions with minimal energy cost.
Professor Shen Xi from the Hong Kong Polytechnic University explained that the aerogel efficiently absorbs moisture and releases it into spaces of various sizes, making it suitable for simple, highly scalable seawater desalination devices that operate without external energy.
Researchers note that access to clean drinking water has become increasingly critical in recent years, particularly in hot, densely populated countries in Asia and Africa. Scientists are exploring various solutions, such as devices that extract moisture from air or desalinate seawater at low energy cost.
To address this challenge, Chinese physicists have improved aerogel, a sponge-like solid with extremely high porosity. By adjusting pore size, the material selectively absorbs water molecules from seawater or brine and converts them into steam under sunlight.
The physicists prepared several aerogels made from carbon nanotubes and cellulose nanofibers and tested their interaction with seawater samples under sunlight. Through experimentation, they identified the optimal pore size that allows water to be actively absorbed by the aerogel and converted into steam under solar heating, even when the material is thick and large in area.
Compared to existing technologies, this material offers significant advantages: current systems experience a sharp drop in efficiency as desalinator size increases. When the aerogel is floated on the sea surface and covered with a transparent lid, it can desalinate approximately 2L of water per square meter per hour. The physicists conclude that this could lead to the development of inexpensive, efficient seawater desalinations suitable for both industrial and household use in the future.
