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化学学报
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化学学报 ›› 2009, Vol. 67 ›› Issue (16): 1936-1942. 上一篇    

研究论文

最小冰聚体结构单元模型及其对水性质影响的量化分析

彭昌盛   

  1. (中国海洋大学海洋环境与生态教育部重点实验室 青岛 266100)

  • 投稿日期:2008-06-17 修回日期:2009-03-23 发布日期:2009-08-28
  • 通讯作者: 彭昌盛

Simulation of Minimum Ice Structural Unit and Quantitative Analysis of Its Effect on Water Properties

Peng, Changsheng

  

  1. (Educational Ministry Key Laboratory of Marine Environmental Science and Ecology,
    Ocean University of China, Qingdao 266100)
  • Received:2008-06-17 Revised:2009-03-23 Published:2009-08-28
  • Contact: peng changsheng

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被引次数

1

水的一些奇特性质主要源于水分子之间存在的氢键, 但在分子尺度上的氢键结构和数据仍是目前研究和争论的焦点. 统计分析了目前文献中普遍采用的水分子和氢键结构数据, 并在此基础上应用AutoCAD图形软件模拟出(H2O)10结构的最小冰聚体结构单元(Minimum Ice Structural Unit, MISU)模型, 以及由MISU聚合而成的冰晶体三维模型. 根据MISU模型, 可以计算得到冰在0 ℃融化为水、水由0 ℃加热至100 ℃、水在100 ℃汽化为水蒸气的三相转化过程中分别需要吸收5.86, 4.40和24.94 kJ•mol－1的能量以断裂16.7%, 12.5%和70.8%的氢键. 如若不考虑氢键的影响, 那么计算得到水的融化热和汽化热分别为0.15和15.73 kJ•mol－1, 与VIA族氢化物H2S, H2Se, H2Te的融化热和汽化热基本呈线性关系. 另外, 由MISU模型计算得到冰在0 ℃融化为水时, 密度由923.17 kg•m－3增至999.89 kg•m－3, 亦与实际测量数据基本一致.

关键词: 最小冰聚体结构单元(MISU), 氢键, 模拟, 量化分析

Based on the collection and selection of the parameters of water molecules and hydrogen bonds, configurations of a minimum ice structure unit (MISU) and ice crystal were simulated step by step thanks for the AutoCAD software. The simulation indicates that a minimum ice structure unit is made up of 10 H2O molecules in a four-hexagon cage structure. Based on the simulation, 1 mole of ice crystal contains 2 mole of hydrogen bonds, and 16.7% of hydrogen bonds (5.86 kJ•mol－1), 12.5% of hydrogen bonds (4.40 kJ• mol－1) and 70.8% of hydrogen bonds (24.94 kJ•mol－1) should be broken during the processes of ice fusion at 0 ℃, water calefaction from 0 to 100 ℃, and water vaporization at 100 ℃ respectively. The fusion and vaporization enthalpy values of water are 0.15 and 15.73 kJ•mol－1, which are consistent with the values of hydrides of Group VIA (H2O, H2S, H2Se, H2Te). Density of ice 923.17 kg•m－3 increased to that of water 999.89 kg•m－3 during ice fusion at 0 ℃, which could also be calculated based on the MISU simulation.

Key words: minimum ice structural unit (MISU), hydrogen bond, simulation, quantitative analysis