Yamada Yutaka, Oka Junya, Isobe Kazuma, Horibe Akihiko
Faculty of Environmental, Life, Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka Kita-ku, Okayama 700-8530, Japan.
Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka Kita-ku, Okayama 700-8530, Japan.
Langmuir. 2024 Aug 13;40(32):16994-17000. doi: 10.1021/acs.langmuir.4c01942. Epub 2024 Jul 30.
Development of freshwater resources is vital to overcoming severe worldwide water scarcity. Fog harvesting has attracted attention as a candidate technology that can be used to obtain fresh water from a stream of foggy air without energy input. Drainage of captured droplets from fog harvesters is necessary to maintain the permeability of harp-shaped harvesters. In the present study, we investigated the effect of the droplet-removal process on the amount of water harvested using a harvester constructed by wettability-controlled wires with an alternating and staggered arrangement. Droplet transfer from hydrophobic to hydrophilic wires, located upstream and downstream of the fog flow, respectively, was observed with a fog velocity greater than 1.5 m/s. The proportion of harvesting resulting from droplet transfer exceeded 30% of the total, and it reflected more than 20% increase of the harvesting performance compared with that of a harvester with wires of the same wettability: this value varied with the adhesive property of the wires and fog velocity. Scaled-up and multilayered harvesters were developed to enhance harvesting performance. We demonstrated certain enhancements under multilayered conditions and obtained 15.99 g/30 min as the maximum harvested amount, which corresponds to 13.3% of the liquid contained in the fog stream and is enhanced by 10% compared with that without droplet transfer.
淡水资源的开发对于克服全球严重的水资源短缺至关重要。雾收集作为一种无需能量输入就能从雾气流中获取淡水的候选技术，已引起关注。对于竖琴形状的雾收集器，排出捕获的水滴对于维持其渗透性是必要的。在本研究中，我们使用由具有交替和交错排列的可控润湿性金属丝构建的收集器，研究了水滴去除过程对收集水量的影响。当雾流速大于1.5 m/s时，观察到水滴从分别位于雾流上游和下游的疏水金属丝转移到亲水金属丝上。由水滴转移导致的收集比例超过总量的30%，与具有相同润湿性金属丝的收集器相比，其反映出收集性能提高了20%以上：该值随金属丝的粘附特性和雾流速而变化。为提高收集性能，开发了放大的多层收集器。我们在多层条件下展示了一定的增强效果，并获得了15.99 g/30 min的最大收集量，这相当于雾流中所含液体的13.3%，与没有水滴转移的情况相比提高了10%。
