Silica Under Water Attack: Surfaces, Defects, and Nano-Structures

水侵蚀下的二氧化硅：表面、缺陷和纳米结构

• 批准号: 0804407
• 负责人: Hai-Ping Cheng
• 金额: $ 43.8万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-15 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0804407&HistoricalAwards=false
• 关键词: Silica; Under; Water; Attack; Surfaces

TECHNICAL SUMMARY:This award supports theoretical research and education into understanding the physical principles underlying processes in silica-water systems at macro- and nano-scale. The strength of silica-water interactions ranges from van der Waals to covalent depending on local mechanical and chemical conditions. External or internal stress also plays a vital role in modifying the interaction. The mechanical and optical properties of silica in aqueous environments and electronic structures at the water-silica interface are entangled. Large-scale computer simulations based on first principles are powerful tools for predicting materials behavior. This research develops theoretical descriptions of (1) stability of dry quartz surfaces and solid-to-liquid transition of water on silica surfaces, (2) surface defects and optical properties modified by adsorbed molecules or nano-clusters and water, and (3) silica nano-pores and channels filled with water and phenomena due to nanoconfinement and stress. The second phase of the research consists of (1) improving models for interfaces between quantum and classical regions, (2) constructing a computing architecture to integrate modern computer codes for parallel computing, and (3) implementing the quasi-particle self-consistent so-called GW method. The effort undertaken has broader impacts with both scientific and educational consequences. The research includes implementing the GW method in a general public license (GPL) electronic structure code so that it is freely available to the larger scientific community. Educationally, students will receive training in the application of both analytical and computational skills and the research helps develop broad interest and skills in the frontiers of electronic structure calculations and multiscale modeling. Aspects of the research, particularly the underlying computational techniques, form part of the subject matter of the advanced physics course ''Physical modeling and simulation'' developed by the PI at her university.NONTECHNICAL SUMMARY:This award supports theoretical research and education into understanding the physical principles underlying processes in silica-water systems. Silica is a simple molecule with one atom of silicon and two atoms of oxygen bound together. The material is common in nature being recognized as sand or quartz. It is a principal component of glass and substances such as concrete. Silica is the most abundant mineral in the earth's crust. Similarly, water is one of most abundant molecules on the Eath's surface. The proposal research helps understand the complex interactions between these two common materials. Researchers will use theoretical and computational tools to study the electronic structure of water on silica surfaces and will be able to investigate the chemical processes that then take place. Large-scale computer simulations based on first principles are powerful tools used for predicting the materials behavior. The effort undertaken has broader impacts with both scientific and educational consequences. The research includes implementing the computational methods in a computer code that it is freely available to the larger scientific community. Educationally, students will receive training in the application of both analytical and computational skills and the research helps develop broad interest and skills in the frontiers of electronic structure calculations and multiscale modeling. Aspects of the research, particularly the underlying computational techniques, form part of the subject matter of the advanced physics course ''Physical modeling and simulation'' developed by the PI at her university.

技术摘要：该奖项支持理论研究和教育，以理解宏观和纳米级硅水系统中的物理原理。二氧化硅相互作用的强度范围从范德华到共价，具体取决于局部机械和化学条件。外部或内部压力在修改相互作用中也起着至关重要的作用。在水环环境中二氧化硅的机械和光学特性纠缠在一起。基于第一原理的大规模计算机模拟是预测材料行为的强大工具。这项研究开发了（1）（1）干石英表面的稳定性以及二氧化硅表面上的水的固体到液过渡的稳定性，（2）表面缺陷和通过吸附的分子或纳米群和水的吸附分子和水的光学特性，以及（3）含有硅胶同变型和nano-Pores和Manne的nano-por和NananeNANECENEN和NANANECENENS和NANANECENENS。研究的第二阶段包括（1）改进量子和经典区域之间接口的模型，（2）构建计算体系结构以整合现代计算机代码以进行并行计算，以及（3）实现准粒子自洽的所谓GW方法。所进行的努力对科学和教育后果产生了更大的影响。该研究包括在通用公共许可证（GPL）电子结构代码中实施GW方法，以便为更大的科学界免费使用。在教育上，学生将接受分析和计算技能的应用培训，研究有助于发展电子结构计算和多尺度建模前沿的广泛兴趣和技能。该研究的各个方面，尤其是潜在的计算技术，构成了PI在她的大学中PI开发的先进物理课程“物理建模和仿真”的主题的一部分。本地技术摘要：该奖项支持理论研究和教育，理解硅水系统中基础过程的物理原理。二氧化硅是一个简单的分子，具有一个硅原子和两个结合的氧原子。该材料在本质上很常见被识别为沙子或石英。 它是玻璃和混凝土等物质的主要成分。二氧化硅是地壳中最丰富的矿物。同样，水是Eath表面上最丰富的分子之一。提案研究有助于了解这两种常见材料之间的复杂相互作用。研究人员将使用理论和计算工具研究二氧化硅表面上水的电子结构，并能够研究然后进行的化学过程。基于第一原理的大规模计算机模拟是用于预测材料行为的强大工具。 所进行的努力对科学和教育后果产生了更大的影响。该研究包括在计算机代码中实施计算方法，该计算方法可自由使用该计算机代码。在教育上，学生将接受分析和计算技能的应用培训，研究有助于发展电子结构计算和多尺度建模前沿的广泛兴趣和技能。研究的各个方面，尤其是潜在的计算技术，是高级物理课程“物理建模和仿真”主题的一部分。