Issue

Vol. 18 (2026)

Superhydrated Zwitterionic Hydrogel with Dedicated Water Channels Enables Nonfouling Solar Desalination

https://doi.org/10.1007/s40820-025-01937-4
Panpan Zhang
Engineering Research Center of Seawater Utilization Technology of Ministry of Education, Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Tianjin Key Laboratory of Chemical Process Safety, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, People’s Republic of China
Hanxue Liang
Research Center for Analytical Sciences, Tianjin Key Laboratory of Biosensing and Molecular Recognition, College of Chemistry, Nankai University, Tianjin 300071, People’s Republic of China
Yawei Du
Engineering Research Center of Seawater Utilization Technology of Ministry of Education, Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Tianjin Key Laboratory of Chemical Process Safety, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, People’s Republic of China
Haiyang Wang
Engineering Research Center of Seawater Utilization Technology of Ministry of Education, Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Tianjin Key Laboratory of Chemical Process Safety, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, People’s Republic of China
Yaqi Tian
Engineering Research Center of Seawater Utilization Technology of Ministry of Education, Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Tianjin Key Laboratory of Chemical Process Safety, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, People’s Republic of China
Jingtao Bi
Engineering Research Center of Seawater Utilization Technology of Ministry of Education, Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Tianjin Key Laboratory of Chemical Process Safety, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, People’s Republic of China
Lei Wang
Engineering Research Center of Seawater Utilization Technology of Ministry of Education, Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Tianjin Key Laboratory of Chemical Process Safety, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, People’s Republic of China
Zhiyuan Guo
Engineering Research Center of Seawater Utilization Technology of Ministry of Education, Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Tianjin Key Laboratory of Chemical Process Safety, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, People’s Republic of China
Jing Wang
Engineering Research Center of Seawater Utilization Technology of Ministry of Education, Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Tianjin Key Laboratory of Chemical Process Safety, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, People’s Republic of China
Zhi‑Yong Ji
Engineering Research Center of Seawater Utilization Technology of Ministry of Education, Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Tianjin Key Laboratory of Chemical Process Safety, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, People’s Republic of China
Liangti Qu
Key Laboratory of Organic Optoelectronics & Molecular Engineering, Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084, People’s Republic of China

Corresponding Author: Liangti Qu

lqu@mail.tsinghua.edu.cn

Nano-Micro Letters, Vol. 18 (2026), Article Number: 87

Abstract

Solar-driven interfacial desalination (SID) offers a sustainable route for freshwater production, yet its long-term performance is compromised by salt crystallization and microbial fouling under complex marine conditions. Zwitterionic polymers offer promising nonfouling capabilities, but current zwitterionic hydrogel-based solar evaporators (HSEs) suffer from inadequate hydration and salt vulnerability. Inspired by the natural marine environmental adaptive characteristics of saltwater fish, we report a superhydrated zwitterionic poly(trimethylamine N-oxide, PTMAO)/polyacrylamide (PAAm)/polypyrrole (PPy) hydrogel (PTAP) with dedicated water channels for efficient, durable, and nonfouling SID. The directly linked N⁺ and O⁻ groups in PTMAO establish a robust hydration shell that facilitates rapid water transport while resisting salt and microbial adhesion. Integrated PAAm and PPy networks enhance mechanical strength and photothermal conversion. PTAP achieves a high evaporation rate of 2.35 kg m−2 h−1 under 1 kW m–2 in 10 wt% NaCl solution, maintaining stable operation over 100 h without salt accumulation. Furthermore, PTAP effectively resists various foulants including proteins, bacterial, and algal adhesion. Molecular dynamics simulations reveal that the exceptional hydration capacity supports its nonfouling properties. This work advances the development of nonfouling HSEs for sustainable solar desalination in real-world marine environments.


Highlights:
1 A superhydrated zwitterionic poly(trimethylamine N-oxide, PTMAO)/polyacrylamide/polypyrrole hydrogel (PTAP) with dedicated water channels is proposed for nonfouling solar desalination.
2 The directly linked N⁺ and O⁻ groups in PTMAO establish a robust hydration shell that facilitates rapid water transport while resisting salt and microbial adhesion.
3 PTAP achieves a high evaporation rate of 2.35 kg m−2 h−1 under 1 kW m–2 in 10 wt% NaCl solution for 100 h without salt accumulation, and can resists various foulants including proteins, bacterial, and algal adhesion.

Keywords

Zwitterionic hydrogel Strong hydration Nonfouling ability Sustainable solar desalination Complex marine environments
Zhang, Panpan, Hanxue Liang, Yawei Du, Haiyang Wang, Yaqi Tian, Jingtao Bi, Lei Wang, Zhiyuan Guo, Jing Wang, Zhi‑Yong Ji, and Liangti Qu. 2025. “Superhydrated Zwitterionic Hydrogel With Dedicated Water Channels Enables Nonfouling Solar Desalination”. Nano-Micro Letters 18 (December):87. https://doi.org/10.1007/s40820-025-01937-4.
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