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Tailoring the Desorption Behavior of Hygroscopic Gels for Atmospheric Water Harvesting in Arid Climates

Lu, Hengyi and Shi, Wen and Zhang, James H. and Chen, Amylynn C. and Guan, Weixin and Lei, Chuxin and Greer, Julia R. and Boriskina, Svetlana V. and Yu, Guihua (2022) Tailoring the Desorption Behavior of Hygroscopic Gels for Atmospheric Water Harvesting in Arid Climates. Advanced Materials, 34 (37). Art. No. 2205344. ISSN 0935-9648. doi:10.1002/adma.202205344.

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The ubiquitous nature of atmospheric moisture makes it a significant water resource available at any geographical location. Atmospheric water harvesting (AWH) technology, which extracts moisture from ambient air to generate clean water, is a promising strategy to realize decentralized water production. The high water uptake exhibited by salt-based sorbents makes them attractive for AWH, especially in low relative humidity (RH) environments. Salt-based sorbents often have relatively high desorption heat, rendering water release an energy-intensive process. We proposed a hygroscopic gel, PAM hydrogel controlled incorporated with LiCl, capable of effective moisture harvesting from arid environments. The interactions between the hydrophilic hydrogel network and the captured water enable the PAM-LiCl to accumulate more free and weakly-bonded water molecules, significantly lowering the desorption heat compared with conventional neat salt sorbents. Benefiting from the affinity for swelling of the polymer backbones, the developed PAM-LiCl achieves a high water uptake of ca. 1.1 g/g at 20% RH with fast sorption kinetics of ca. 0.008 g g⁻¹ min⁻¹ and further demonstrates a daily water yield up to ca. 7 g/g at this condition. These findings provide a new pathway for synthesis of materials with efficient water absorption/desorption properties, to reach energy-efficient water release for AWH in arid climates.

Item Type:Article
Related URLs:
URLURL TypeDescription Information
Greer, Julia R.0000-0002-9675-1508
Yu, Guihua0000-0002-3253-0749
Additional Information:© 2022 John Wiley & Sons. Accepted manuscript online: 28 July 2022. Manuscript revised: 11 July 2022. Manuscript received: 13 June 2022. H.L., S.W., and J.Z. contributed equally to this work.G.Y. acknowledges the financial support from the U.S. Defense Advanced Research Projects Agency (DARPA) Atmospheric Water Extraction (AWE) Program under Contract No. HR0011-20-C-0055. The authors declare no conflict of interest.
Funding AgencyGrant Number
Defense Advanced Research Projects Agency (DARPA)HR0011-20-C-0055
Subject Keywords:Atmospheric water harvesting; Desorption; Hydrogel; Sorbent; Water-material interaction
Issue or Number:37
Record Number:CaltechAUTHORS:20220729-722279000
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Official Citation:Lu, H., Shi, W., Zhang, J.H., Chen, A.C., Guan, W., Lei, C., Greer, J.R., Boriskina, S.V. and Yu, G. (2022), Tailoring the Desorption Behavior of Hygroscopic Gels for Atmospheric Water Harvesting in Arid Climates. Adv. Mater.. Accepted Author Manuscript 2205344.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:115971
Deposited By: George Porter
Deposited On:29 Jul 2022 21:27
Last Modified:08 Feb 2023 00:01

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