Department of Civil Infrastructure and Environment Engineering, Masdar Institute, Khalifa University of Science and Technology , Abu Dhabi, United Arab Emirates.
Department of Mechanical & Material Science and Engineering, Masdar Institute, Khalifa University of Science and Technology , Abu Dhabi, United Arab Emirates.
ACS Nano. 2017 Dec 26;11(12):12318-12325. doi: 10.1021/acsnano.7b06114. Epub 2017 Nov 21.
Cloud-seeding materials as a promising water-augmentation technology have drawn more attention recently. We designed and synthesized a type of core/shell NaCl/TiO (CSNT) particle with controlled particle size, which successfully adsorbed more water vapor (∼295 times at low relative humidity, 20% RH) than that of pure NaCl, deliquesced at a lower environmental RH of 62-66% than the hygroscopic point (h., 75% RH) of NaCl, and formed larger water droplets ∼6-10 times its original measured size area, whereas the pure NaCl still remained as a crystal at the same conditions. The enhanced performance was attributed to the synergistic effect of the hydrophilic TiO shell and hygroscopic NaCl core microstructure, which attracted a large amount of water vapor and turned it into a liquid faster. Moreover, the critical particle size of the CSNT particles (0.4-10 μm) as cloud-seeding materials was predicted via the classical Kelvin equation based on their surface hydrophilicity. Finally, the benefits of CSNT particles for cloud-seeding applications were determined visually through in situ observation under an environmental scanning electron microscope on the microscale and cloud chamber experiments on the macroscale, respectively. These excellent and consistent performances positively confirmed that CSNT particles could be promising cloud-seeding materials.
近年来，作为一种有前途的人工增雨技术，云凝结核材料引起了更多的关注。我们设计并合成了一种具有可控粒径的核壳型 NaCl/TiO（CSNT）粒子，它比纯 NaCl 成功吸附了更多的水蒸气（在低相对湿度 20%RH 时约为 295 倍），在比吸湿点（75%RH）低的环境 RH 62-66%时潮解，并且形成了比原始测量尺寸大 6-10 倍的更大水滴，而纯 NaCl 在相同条件下仍保持为晶体。这种增强的性能归因于亲水性 TiO 壳和吸湿 NaCl 核微结构的协同效应，它吸引了大量水蒸气并使其更快地变成液体。此外，根据其表面亲水性，通过经典的 Kelvin 方程预测了 CSNT 粒子作为云凝结核材料的临界粒径（0.4-10 μm）。最后，通过环境扫描电子显微镜在微观尺度上和云室实验在宏观尺度上对原位观察，分别确定了 CSNT 粒子在云催化应用中的效益。这些优异且一致的性能积极证实 CSNT 粒子可能成为有前途的云凝结核材料。
