Graduate School of Science, Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522 (Japan).
Angew Chem Int Ed Engl. 2014 Jul 28;53(31):8032-6. doi: 10.1002/anie.201403839. Epub 2014 Jun 4.
Water surrounded by hydrophobic interfaces affects a variety of chemical reactions and biological activities. Carbon nanotubes (CNTs) can be used to investigate the behavior of water at hydrophobic interfaces. Here, we determined the fundamental unit of water by evaluating the ice-like cluster formation of water in the limited hydrophobic nanospaces of CNTs, using X-ray diffraction and molecular simulation analysis. The water in CNTs with a diameter of 1 nm had fewer hydrogen bonds than bulk water under ambient conditions. In CNTs with diameters of 2 and 3 nm, water formed nanoclusters even under ambient conditions, because of prolific hydrogen bonding; predominant ice-like cluster formation was induced in the 2-3 nm nanospaces. The results confirming the cluster formation in the CNTs also demonstrated that the critical cluster size was 0.8-3.4 nm. The fundamental cluster size was 0.8 nm; these results indicated that 0.8 nm clusters are the fundamental units of water assemblies.
被疏水界面包围的水会影响各种化学反应和生物活性。碳纳米管（CNTs）可用于研究疏水界面处水的行为。在这里，我们通过评估水在 CNTs 的有限疏水纳米空间中形成类似冰的簇的行为，使用 X 射线衍射和分子模拟分析来确定水的基本单元。在环境条件下，直径为 1nm 的 CNTs 中的水的氢键比体相水少。在直径为 2nm 和 3nm 的 CNTs 中，由于丰富的氢键，水甚至在环境条件下也形成纳米簇，在 2nm-3nm 的纳米空间中会诱导形成类似冰的簇。在 CNTs 中证实了簇形成的结果还表明临界簇尺寸为 0.8nm-3.4nm。基本簇尺寸为 0.8nm；这些结果表明，0.8nm 簇是水组装的基本单元。
