在大气相关温度下水纳米颗粒的结晶,化和结构
Jessica C Johnston1, Valeria Molinero
1Department of Chemistry, University of Utah, Salt Lake City, Utah 84112-0850, USA.
Journal of the American Chemical Society
|March 29, 2012
概括
在冷过程中,水纳米粒子形成混合冰 I 结构. 它们的融化温度随着大小的增加而降低,遵循吉布斯-姆森方程,这对于大气冰研究至关重要.
科学领域:
- 大气化学 大气化学
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
背景情况:
- 水纳米粒子在大气过程中至关重要.
- 了解它们的相位转换和冰结构至关重要,但不完整.
研究的目的:
- 研究水纳米粒子的不平衡结和平衡化.
- 确定结晶过程中形成的冰的结构.
- 分析粒子大小对相位转换和化温度的影响.
主要方法:
- 使用mW水模型进行分子动力学模拟.
- 模拟的水纳米粒子半径从1到4.7纳米.
- 在150到200K之间的温度下结晶.
主要成果:
- 形成的冰是立方和六角冰I (约. 2:1比率),独立于粒子大小.
- 加热导致奥斯瓦尔德的成熟和回火,在融化之前增加冰含量.
- 融化温度随着颗粒大小的下降而下降,用吉布斯-姆森方程描述了预融层.
- 结温度也随着粒子半径的减少而降低.
结论:
- 这项研究阐明了水纳米粒子的结和融化行为.
- 这些发现为大气冰颗粒的结构和相变提供了洞察力.
- 结果有助于更好地了解大气条件下的水的行为.
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