Kinetics of Sorption in Hygroscopic Hydrogels
Name
KineticsofSorptioninHygroscopicHydrogels.pdf
Description
Accepted version
Size
3.97 MB
Format
Adobe PDF
Checksum (MD5)
47f32cda850ad643c471e3f1952f0915
Author(s)
Díaz-Marín, Carlos D
Zhang, Lenan
Lu, Zhengmao
Alshrah, Mohammed
Grossman, Jeffrey C
Wang, Evelyn N
Date Issued
January 21, 2022
Journal
Nano Letters
Publisher
American Chemical Society (ACS)
Citation
Díaz-Marín, Carlos D, Zhang, Lenan, Lu, Zhengmao, Alshrah, Mohammed, Grossman, Jeffrey C et al. 2022. "Kinetics of Sorption in Hygroscopic Hydrogels." Nano Letters.
Version
Author's final manuscript
Abstract
Hygroscopic hydrogels hold significant promise for high-performance atmospheric water harvesting, passive cooling, and thermal management. However, a mechanistic understanding of the sorption kinetics of hygroscopic hydrogels remains elusive, impeding an optimized design and broad adoption. Here, we develop a generalized two-concentration model (TCM) to describe the sorption kinetics of hygroscopic hydrogels, where vapor transport in hydrogel micropores and liquid transport in polymer nanopores are coupled through the sorption at the interface. We show that the liquid transport due to the chemical potential gradient in the hydrogel plays an important role in the fast kinetics. The high water uptake is attributed to the expansion of hydrogel during liquid transport. Moreover, we identify key design parameters governing the kinetics, including the initial porosity, hydrogel thickness, and shear modulus. This work provides a generic framework of sorption kinetics, which bridges the knowledge gap between the fundamental transport and practical design of hygroscopic hydrogels.
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
Massachusetts Institute of Technology. Department of Materials Science and Engineering
Terms of Use
Creative Commons Attribution-Noncommercial-Share Alike
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DOI of Published Version
https://doi.org/10.1021/acs.nanolett.1c04216
