New salty gel could harvest water from desert air
June 15, 2023 – MIT engineers have synthesized a superabsorbent material that can soak up a record amount of moisture from the air, even in desert-like conditions. Even in very dry conditions, with 30 percent relative humidity, the material can pull vapor from the air and hold in the moisture without leaking. The water could then be heated and condensed, then collected as ultrapure water.
The transparent, rubbery material is made from hydrogel, a naturally absorbent material that is also used in disposable diapers. The team enhanced the hydrogel’s absorbency by infusing it with lithium chloride – a type of salt that is known to be a powerful dessicant.
After extensive testing, the team reports that at very dry conditions of 30 percent relative humidity, the gels captured a ‘record-breaking’ 1.79 grams of water per gram of material.
