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Molecular Models Applied to the Heterogeneous Nucleation of Ice: Ice Formation on Surfaces

应用于冰异质成核的分子模型：表面冰的形成

基本信息

批准号：
8713827
负责人：
Barbara Hale
金额：
$ 11.5万
依托单位：
Missouri University of Science and Technology
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
1988
资助国家：
美国
起止时间：
1988-03-15 至 1992-02-13
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=8713827&HistoricalAwards=false
关键词：
Molecular Models Applied Heterogeneous Nucleation

项目摘要

Professor Barbara Hale will apply computer models of water/ice systems and a scaled nucleation rate formalism to the study of heterogeneous ice nucleation. The goals are to characterize ice nucleating features of natural atmospheric and artificial ice nuclei in terms of microscopic substrate properties and develop analytic the which provide microscopic substrate properties and develop analytic the which provide convenient estimates of threshold temperatures and heterogeneous nucleation rates. Specifically, threshold temperatures for ice formation in adsorbed water layers on model substrates (such as a model silver iodide basal face and a model hydroxylated silica surface) and on substrates with modified water.substrate interactions will be examined for effects of: (1) substrate lattice structure, (2) water.substrate binding energy, (3) substrate ledge defects, (4) external electric field and pressure pulse perturbations, and (5) thickness of the condensed water layers. The computer simulations use effective water.water and water.substrate atomic pair potentials and Monte Carlo techniques to generate canonical ensemble averages of thermodynamic quantities for the adsorbed water/ice systems. This work is important because it provides quantitative descriptions of the heterogeneous phase change mechanism, in particular, the ice phase formation.

芭芭拉黑尔教授将应用计算机模型，水/冰系统和成核率的比例形式主义，非均质冰成核研究这些目标表征自然大气的冰成核特征，人工冰核的微观基质性质和发展分析，提供微观基板性能和开发分析提供阈值温度和非均匀性的方便估计成核速率具体来说，冰的临界温度在模型基底上的吸附水层中形成（例如，模型银化底面和模型羟基化二氧化硅表面）和具有改性水的基材上。基材将检查相互作用的影响：（1）底物晶格结构，（2）水-基质结合能，（3）衬底台阶缺陷;（4）外加电场和压力脉冲扰动;（5）凝结水厚度层次。计算机模拟使用有效的水。水和水、基质原子对势和蒙特卡罗方法生成热力学的正则系综平均值吸附水/冰系统的量。这项工作很重要，因为它提供了定量的非均相相变机制的描述，尤其是冰相的形成。