2026-05-07 スタンフォード大学
＜関連情報＞
- https://news.stanford.edu/stories/2026/05/hydrogel-potable-water-research
- https://www.nature.com/articles/s41467-026-71987-8
- https://www.cell.com/device/fulltext/S2666-9986(25)00111-5
金属媒介分解を防ぐことによる吸湿性ハイドロゲルの長期安定性 Long-term stability of moisture-capturing hydrogels by preventing metal-mediated degradation
Carlos D. Díaz-Marín,Chad T. Wilson,Won Jun Song,Xiao-Yun Yan,Yuran Shi,Shucong Li,Chang Liu,Emily Lin,Yang Zhong,Lorenzo Masetti &Xuanhe Zhao
Nature Communications Published:07 May 2026
DOI:https://doi.org/10.1038/s41467-026-71987-8
Abstract
Sorbent-based atmospheric water harvesting promises passive, geography-independent, and economical freshwater production. Achieving low water cost through moisture harvesting demands inexpensive, high-performance, and durable sorbents. Among all sorbents, hydrogel salt-composites have exceptional performance at a low cost. However, hydrogel durability has so far been overlooked, ultimately preventing moisture capture from realizing reliable, inexpensive water production. In this work, we systematically study hydrogel-salt composite degradation under different conditions. We demonstrate that commonly used polyacrylamide-lithium chloride (PAM-LiCl) are intrinsically durable, with a limited decrease (~50%) in their elastic moduli, even at elevated temperatures (75 °C) and for prolonged durations (>8 months). In contrast, degradation quickly occurs (<3 weeks) when these hydrogels interface with copper and copper oxides, as is common practice in moisture-harvesting devices or for polyvinyl alcohol-lithium chloride hydrogels (in <50 days). We rationalize these results through a proposed metal-mediated degradation mechanism involving hydroxyl radical generation, which is consistent with our PAM-LiCl observations, including ion concentration measurements and experiments with other metals. With the insights from our experiments and proposed mechanism, we implement coatings which prevent hydrogel degradation. This enables stable cyclic moisture absorption-desorption (>190 cycles) and provides a path towards <0.01 $/L water from moisture.
吸湿性ハイドロゲルデバイスの物理学に基づく最適化によるアタカマ砂漠における太陽光を利用した大気水採取 Solar-driven atmospheric water harvesting in the Atacama Desert through physics-based optimization of a hygroscopic hydrogel device
Chad T. Wilson ∙ Carlos D. Díaz-Marín ∙ Juan Pablo Colque ∙ Joseph P. Mooney ∙ Bachir El Fil
Device Published: May 9, 2025
DOI:https://doi.org/10.1016/j.device.2025.100798
The bigger picture
Water scarcity is one of the most pressing challenges of our time, threatening the health, economy, and stability of communities worldwide. Traditional solutions like desalination and centralized water-supply systems are successfully deployed in many areas globally but are often expensive, energy intensive, and impractical for remote or arid regions. By harnessing sunlight—a ubiquitous, renewable resource—we developed a passive sorbent-based atmospheric water-harvesting device that captures moisture directly from the air using a hydrogel-salt composite. Our approach shifts the focus from merely improving material performance to optimizing an entire system based on fundamental physical principles of heat and mass transport. The device integrates a hydrogel-salt composite to capture and release water with an optimally designed housing for effective solar absorption, vapor collection, and water condensation. This integration creates a low-cost, scalable technology that can generate potable water even in extreme environments like the Atacama Desert, where conventional water sources fail.
By addressing both the material and system-level challenges, our research not only advances the field of sorbent-based atmospheric water harvesting but also provides a viable solution to global water scarcity. This breakthrough could enable decentralized water production in water-stressed regions, offering a sustainable alternative that meets the needs of communities facing limited access to safe drinking water.
Highlights
•Solar-driven atmospheric water-harvesting device produces water in the Atacama Desert
•Device optimally designed using a heat and mass transport model of the system
•Fully leverages material performance of a hydrogel-salt composite
•Considerations for scalability and cost when deploying the device
Summary
Moisture-capturing hydrogels are promising material candidates for atmospheric water-harvesting (AWH) systems, potentially addressing the increasingly global challenge of water scarcity. However, despite material-level performance improvements, optimal system integration of hydrogels remains a major limitation to deploying cost-effective, high-performance devices. Here, we design, optimize, and demonstrate deployment of polyacrylamide-lithium chloride (PAM-LiCl) hydrogels in a passive AWH device to provide liquid water with high thermal efficiency. First, a comprehensive heat and mass transport model is developed to enable optimal device architecture design. We then validate this design through fabrication and testing in a variety of extreme environmental conditions. Overall, we present a holistically optimized sorption system and demonstrate water production up to 1.7 L/m2/day with 16% thermal efficiency. This work highlights the potential for system-level improvement of AWH devices and provides initial design guidelines for producing optimal systems with regards to both material performance and environmental conditions.
