Preparation of Calcium Alginate-Based Hydrogels with Precisely Designed Centrosymmetric Geometries for Efficient Water Evaporation in Response to Different Solar Incidence Angles

• DOI: 10.1021/acsami.4c20180
• Publication Date: 2025-01-15T11:05:21Z
• Authors: Xiaoyang Fang; Wei Li; Changjun Li; Fan-Zhen Jiao; Zhi-Hao Wang; Shumiao Li; Fu-Lin Gao; Zhong-Zhen Yu; Xiaofeng Li
• Keywords: Calcium alginate

Hydrogels are popular materials for desalination and can significantly reduce the vaporization enthalpy of water; however, there few reports on hydrogels with a controllable multilevel structural design water evaporation. Herein, calcium alginate traditional Chinese ink-based evaporator (CIE) proposed fabricated using directed freezing technology to construct radial channels, followed by freeze-drying physical cross-linking. Because squeezing ice crystals shaping effect PDMS template, prepared exhibits sea-urchin-shaped highly geometrical centrosymmetric structure numerous pore which promotes rapid transport under different solar incidence angles as sun rotates well overcomes shrinkage hydrogel caused insufficient supply. Additionally, channels in spherical overcome limitation saltwater being continuously concentrated same area where evaporation rate is highest. As result, urchin-structured CIE 3.52 kg m–2 h–1 at 1 irradiation, 45.5% higher than that unpatterned CIE. This provides strategy fabrication an all-day hydrogel-based without irradiation.