Numerous adsorbents have been developed to extract water from air by sorption-based atmospheric water harvesting (SAWH). However, laboratory-level studies on the water uptake performance of adsorbents usually use materials with small mass such as microgram or milligram level. These findings may not be well adapted to scale-up applications. Moreover, other problems such as low thermal conductivity and structural instability may arise when the adsorbent is in the powder form. Herein, the effect of dosage scale-up on the water uptake performance of metal–organic framework (MOF) was studied. A compression method was proposed to shape the MOF powder into a block, and three MOFs (CAU-10-H, MOF-303, Ni₂Cl₂(BTDD)) were selected as test samples. The water uptake capacity, sorption kinetics, and adsorption isotherm of both powder and block materials were tested. Through qualitative and quantitative analysis, it was found that from small-scale powder materials to block materials, the step point of the water adsorption isotherm exhibited hysteresis, the water uptake capacity had diminished by about half, the time for MOFs reaching the saturation state increased by 10–20 times, and the adsorption rate coefficient was attenuated by more than 80%. These findings provide useful guidance and new insights for the future research of SAWH, which can help to bridge the gap between material science and engineering application.

中文翻译：

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MOF材料吸水性能放大效应研究

已经开发了许多吸附剂，通过基于吸附的大气水收集 (SAWH) 从空气中提取水。然而，吸附剂吸水性能的实验室级研究通常使用质量较小的材料，例如微克或毫克级。这些发现可能无法很好地适应放大应用。此外，当吸附剂为粉末形式时，可能会出现导热系数低和结构不稳定等其他问题。在此，研究了剂量放大对金属有机骨架（MOF）吸水性能的影响。提出了一种将 MOF 粉末成型为块状的压缩方法，以及三种 MOF（CAU-10-H、MOF-303、Ni ₂ Cl ₂(BTDD)) 被选为测试样本。测试了粉末和块状材料的吸水能力、吸附动力学和吸附等温线。通过定性和定量分析发现，从小尺寸粉体材料到块状材料，吸水等温线的阶跃点呈现滞后现象，吸水能力降低了约一半，MOFs达到饱和状态的时间增加10~20倍，吸附速率系数衰减80%以上。这些发现为SAWH的未来研究提供了有益的指导和新的见解，有助于弥合材料科学与工程应用之间的差距。