Molecular Modeling of Nucleation and Growth of Clathrate Hydrates

笼形水合物成核和生长的分子模型

• 批准号: 1012651
• 负责人: Valeria Molinero
• 金额: $ 36.24万
• 依托单位: University of Utah
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-01 至 2014-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1012651&HistoricalAwards=false
• 关键词: Molecular; Modeling; Nucleation; Growth; Clathrate

Valeria Molinero of the University of Utah is supported by an award from the Chemical Structures, Dynamics and Methods program in the Chemistry Division for a computational study aimed at elucidating microscopic pathways by which clathrate hydrates nucleate and grow from aqueous solutions and from ice. The project combines the power of advanced simulation methods to sample rare nucleation events with atomistic and coarse-grained molecular dynamics simulations. The project tests a transformative hypothesis: that a monatomic model of water with very short-ranged interactions and without hydrogen atoms but able to form the characteristic tetrahedral ?hydrogen-bonded" configurations of water, produces nucleation and grow of clathrates following the same pathways than fully atomistic water models. If this method is validated, it will permit the study of molecular mechanisms at less than 1% of the computational cost. The study is the first to determine the molecular mechanisms of formation and structure of the nuclei for clathrates containing large guest and hydrophilic guests and two distinct guests (double clathrates). It is the first project to investigate the mechanisms of nucleation and growth of clathrates from ice and the structures of the ice/clathrate and ice/guest interfaces using simulations.Clathrate hydrates hold high promise as an abundant energy source, for storage and transportation of natural gas and hydrogen, and for sequestration of carbon dioxide. A prominent challenge for these applications is the slow kinetics of formation of gas hydrate clathrates. On the other hand, clathrate plugs form in oil and gas pipelines, causing enormous economic losses and safety concerns. A key impediment to retard or hasten the crystallization of clathrates is the lack of understanding of the molecular mechanisms by which they nucleate and grow. A professor from Westminster College, an undergraduate institution, is participating in this project, as well as undergraduates and graduate students. The PI and her research group also participate in an outreach program to high schools called "The Leo on Wheels" of the Utah Science Center.

犹他大学的瓦莱里娅·莫利内罗 (Valeria Molinero) 获得了化学部化学结构、动力学和方法项目的奖项，该项目旨在阐明包合物水合成核以及从水溶液和冰中生长的微观途径。该项目结合了先进模拟方法的力量，通过原子和粗粒度分子动力学模拟对罕见的成核事件进行采样。该项目测试了一个变革性的假设：具有非常短程相互作用且没有氢原子但能够形成水的特征四面体“氢键”构型的水单原子模型，按照与完全原子水模型相同的途径产生包合物的成核和生长。如果该方法得到验证，它将允许以不到 1% 的计算成本研究分子机制。该研究是 第一个确定包含大客体和亲水性客体以及两种不同客体（双包合物）的包合物的核形成和结构的分子机制。这是第一个利用模拟研究冰中包合物成核和生长机制以及冰/包合物和冰/客体界面结构的项目。笼形水合物作为一种丰富的能源具有很高的前景，可用于储存和储存。 天然气和氢气的运输以及二氧化碳的封存。这些应用面临的一个突出挑战是气体水合物包合物形成的缓慢动力学。另一方面，石油和天然气管道中形成笼形堵塞，造成巨大的经济损失和安全隐患。延迟或加速包合物结晶的一个关键障碍是缺乏对其分子机制的了解 成核并生长。本科院校威斯敏斯特学院的一名教授以及本科生和研究生正在参与该项目。 PI 和她的研究小组还参加了犹他州科学中心一项名为“车轮上的狮子”的高中推广计划。