Ohba Tomonori, Kanoh Hirofumi, Kaneko Katsumi
Department of Chemistry, Faculty of Science, Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522, Japan.
Chemistry. 2005 Aug 19;11(17):4890-4. doi: 10.1002/chem.200400918.
The growth mechanism of water clusters in carbon nanopores is clearly elucidated by in situ small-angle X-ray scattering (SAXS) studies and grand canonical Monte Carlo (GCMC) simulations at 293-313 K. Water molecules are isolated from each other in hydrophobic nanopores below relative pressures (P/P(0)) of 0.5. Water molecules associate with each other to form clusters of about 0.6 nm in size at P/P(0)=0.6, accompanied by a remarkable aggregation of these clusters. The complete filling of carbon nanopores finishes at about P/P(0)=0.8. The correlation length analysis of SAXS profiles leads to the proposal of a growth mechanism for these water clusters and the presence of the critical cluster size of 0.6 nm leads to extremely stable clusters of water molecules in hydrophobic nanopores. Once a cluster of the critical size is formed in hydrophobic nanopores, the predominant water adsorption begins to fill carbon nanopores.
通过在293 - 313 K下进行的原位小角X射线散射（SAXS）研究和巨正则蒙特卡罗（GCMC）模拟，清晰地阐明了碳纳米孔中水分子簇的生长机制。在相对压力（P/P(0)）低于0.5时，水分子在疏水纳米孔中彼此隔离。在P/P(0)=0.6时，水分子相互缔合形成尺寸约为0.6 nm的簇，同时这些簇会显著聚集。碳纳米孔在约P/P(0)=0.8时完全被填满。SAXS谱的关联长度分析得出了这些水分子簇的生长机制，并且0.6 nm的临界簇尺寸的存在导致疏水纳米孔中水分子形成极其稳定的簇。一旦在疏水纳米孔中形成临界尺寸的簇，主要的水吸附就开始填充碳纳米孔。
