Shrinkage‐Resistant Thermo‐Responsive Hygroscopic Hydrogel Toward Ultra‐Rapid Cycling Atmospheric Water Harvesting
Jiqing Lu, Jie Yan, Feifei Pei, Zhaoxuan Niu, Jiayin Li, Guangping Han, Dong Wang, Yiying Yue, Wanli Cheng
Abstract
Abstract Freshwater scarcity presents a significant threat to socio‐economic development, particularly in agriculture and light industry in remote and underdeveloped regions. Sorption‐based atmospheric water harvesting (SAWH) offers a promising solution, yet the primary challenge remains the efficient and continuous extraction of clean water from air. Here, a supramolecular design strategy is proposed to synthesize shrinkage‐resistant thermos‐responsive hydrogel (PCC20@LiCl) that demonstrates rapid thermal response, stable phase‐transition size, and effective lithium chloride (LiCl) entrapment. The hydrogel achieves high water sorption capacities of 0.99 ± 0.03 and 5.43 ± 0.37 at 20% and 80% relative humidity, respectively, along with a rapid solar‐driven water release rate. Additionally, this study demonstrates a solar‐powered, rapid‐cycling SAWH device that reuses desorption heat to maximize sorbent efficiency. By alternately switching between sorption and desorption chambers, the device completes nine consecutive cycles per day, achieving a water collection rate of 1,417 and 1,134.4 . This work demonstrates the potential to meet domestic and irrigation water demands, advancing SAWH technology for practical implementation in economically underdeveloped regions.