Solar-driven interfacial evaporation is an eco-friendly and promising approach to address freshwater shortage. However, the intricate preparation process and low evaporation rate of evaporators limit its further practical applications. Herein, an ingenious design strategy is proposed for a shape memory Janus (SMJ) foam to controllably increase the evaporation rate. By sequentially adhering trans-1,4-Polyisoprene (TPI) and selectively modifying sodium alginate (SA) / AlCl₃ on PU substrate, a three-dimensional (3D) porous foam structure is conveniently constructed, which features a hydrophobic layer with efficient photothermal conversion and a superhydrophilic layer with sufficient water supply. Under varying light intensities, the evaporation rate of optimized SMJ foam exhibits a linear escalation through shape memory compression, specifically from 1.8 kg m⁻²h⁻¹ to 3.2 kg m⁻²h⁻¹ as the compression ratio increases from 0 to 80 % under one solar irradiation. Due to its large-pore porosity, the photothermal layer increases surface area density and gradually generates analogous vertical channels to enhance absorbance during compression, thereby improving the photothermal conversion effect and optimizing thermal management. Moreover, thanks to the Janus structure, the self-floating and salt-resisting properties of SMJ foam guarantee stable and efficient evaporation in complicated environments. This work introduces a novel strategy for promoting the evaporation rate, intelligence, and industrial application of solar-driven interfacial evaporators.

中文翻译：

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智能制水策略：通过形状记忆 Janus 泡沫可控地提高蒸发速率


太阳能驱动的界面蒸发是解决淡水短缺的一种环保且有前途的方法。然而，蒸发器复杂的制备过程和低蒸发速率限制了其进一步的实际应用。本文提出了一种巧妙的形状记忆 Janus （SMJ） 泡沫设计策略，以可控地提高蒸发速率。通过在 PU 基材上依次粘附反式 1,4-聚异戊二烯 （TPI） 和选择性改性海藻酸钠 （SA） / AlCl₃，可以方便地构建三维 （3D） 多孔泡沫结构，该结构具有高效光热转化的疏水层和具有充足供水的超亲水层。在不同光强度下，优化的 SMJ 泡沫的蒸发速率通过形状记忆压缩表现出线性上升，特别是随着压缩比在一次太阳照射下从 0 增加到 80 %，从 1.8 kg ^{m-2 h-1} 到 3.2 kg ^{m-2 h-1}。由于其大孔隙率，光热层增加了表面积密度，并逐渐产生类似的垂直通道以增强压缩过程中的吸光度，从而提高了光热转换效果并优化了热管理。此外，得益于 Janus 结构，SMJ 泡沫的自浮和耐盐特性保证了在复杂环境中稳定高效的蒸发。这项工作为促进太阳能驱动界面蒸发器的蒸发速率、智能化和工业应用提出了一种新的策略。