Issue

Vol. 18 (2026)

Hydrogel Fiber Evaporator with Vertical Channels Integrated with Dual Heat Supply/Insulation Model for Continuous Solar Desalination

https://doi.org/10.1007/s40820-026-02120-z
Tian Wang
Shandong Key Laboratory of Medical and Health Textile MaterialsCollege of Textiles and ClothingState Key Laboratory of Bio‑Fibers and Eco‑Textiles, Qingdao University, Qingdao 266071, People’s Republic of China
Shuai Gao
Shandong Key Laboratory of Medical and Health Textile MaterialsCollege of Textiles and ClothingState Key Laboratory of Bio‑Fibers and Eco‑Textiles, Qingdao University, Qingdao 266071, People’s Republic of China
Yongli Yu
Shandong Key Laboratory of Medical and Health Textile MaterialsCollege of Textiles and ClothingState Key Laboratory of Bio‑Fibers and Eco‑Textiles, Qingdao University, Qingdao 266071, People’s Republic of China
Zhigang Chen
State Key Laboratory of Advanced Fiber Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, People’s Republic of China
Lili Wang
Shandong Key Laboratory of Medical and Health Textile MaterialsCollege of Textiles and ClothingState Key Laboratory of Bio‑Fibers and Eco‑Textiles, Qingdao University, Qingdao 266071, People’s Republic of China
Xiansheng Zhang
Shandong Key Laboratory of Medical and Health Textile MaterialsCollege of Textiles and ClothingState Key Laboratory of Bio‑Fibers and Eco‑Textiles, Qingdao University, Qingdao 266071, People’s Republic of China

Corresponding Author: Xiansheng Zhang

xshzhang@qdu.edu.cn

Nano-Micro Letters, Vol. 18 (2026), Article Number: 261

Abstract

Hydrogel-based evaporators offer unique advantages for seawater desalination, yet the high verticalization of water transport channels remains significantly constrained by the random arrangement of polymers. Herein, a versatile and scalable “wet-spinning hydrogel fibers assisted with constrained alignment (HFCA)” strategy is proposed to fabricate hierarchically porous hydrogel fiber evaporator, achieving the perfectly vertical, large-scale spaces between adjacent fibers and small-scale pores within the hydrogel itself. The synergistic role of multiscale pores significantly enhances the siphon effect between fibers and the water transport capacity, while improving thermal localization, light absorption, and salt flux. Moreover, rather than employing the popular “heat isolation model”, a dual “heat supply/insulation model” is introduced for the first time in a three-dimensional evaporator, where a novel heating layer providing additional heat to the bulk water, along with an insulation layer minimizing heat loss. Together, these components create a positive net energy balance, transforming the single cold into a combined cold/hot evaporation manner on the side surface. Using this model, the HFCA evaporator exhibits the high evaporation rate (8.09 kg m−2 h−1, 1 KW m−2) among the reported hydrogel-based evaporators and achieves exceptional outdoor evaporation (64.74 kg m−2 for 9 h), accompanied with salt tolerance, anti-oil fouling, and self-cleaning capacities.


Highlights:
1 A versatile yet scalable “wet-spinning hydrogel fibers assisted with constrained alignment (HFCA)” strategy is proposed to achieve a highly vertical hydrogel fiber aggregate with multiscale pore structure.
2 The dual “heat supply/insulation model” transforms the conventional single cold evaporation into cold/hot evaporation on the side surface for the first time, maximizing energy utilization of 3D evaporator.
3 HFCA makes a breakthrough in verticalization of water transport channels and maximum utilization of energy, accompanied with superior salt tolerance, anti-oil fouling and self-cleaning ability.

Keywords

Perfect verticalization Multiscale pores Heat supply/insulation model Cold/hot evaporation Maximum utilization of energy
Wang, Tian, Shuai Gao, Yongli Yu, Zhigang Chen, Lili Wang, and Xiansheng Zhang. 2026. “Hydrogel Fiber Evaporator With Vertical Channels Integrated With Dual Heat Supply/Insulation Model for Continuous Solar Desalination”. Nano-Micro Letters 18 (February):261. https://doi.org/10.1007/s40820-026-02120-z.
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