A hydrogel-based system could offer a long-term solution for harvesting potable water from ambient air, according to a study.
Hydrogels have been researched for many years as a means to produce water at low cost almost anywhere. The materials, which are made of salt and polymers, soak up large amounts of moisture from the air, even in desert-like conditions. The water is then condensed back into liquid water and collected for drinking.
The challenge is that these solar-powered harvesting systems only last for around eight months or 30 cycles of filling up and releasing water before they degrade. A team at Stanford Doerr School of Sustainability explored why this happened and what they could do to create a longer-lasting system that could be scaled.
The hydrogel system they designed uses a highly absorbent salt called lithium chloride and an equally absorbent polymer commonly used in nappies called polyacrylamide. This hydrogel is placed within a 30cm2 metal frame. Painted black, this aluminium...