NIRT: Experimental and Theoretical Investigations of Aqueous Geochemical Interfaces - The Role of Nanoscale and Molecular Structures in Dictating Environmental Reactivity

NIRT：水地球化学界面的实验和理论研究 - 纳米级和分子结构在决定环境反应性中的作用

• 批准号: 0404400
• 负责人: Thomas Trainor
• 金额: $ 143.75万
• 依托单位: University of Alaska Fairbanks Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0404400&HistoricalAwards=false
• 关键词: NIRT; Experimental; Theoretical; Investigations; Aqueous

0404400TrainorThe focus of this proposal is an interdisciplinary approach to molecular and nanoscale investigations of iron-oxide surface structure and reactivity. Intellectual merit of the proposed activity: The research proposed here will utilize state-of-the-art experimental and theoretical methods to provide unique information about the fundamental controls on reactivity of iron-oxides. Experiments using both single crystal substrates and nanoparticle composites of hematite will be used to determine reactivity trends with respect to adsorption of contaminant metal ions, and how these vary with surface orientation, surface quality, and reaction with "surface modifying species". The complementary nature of the proposed techniques will allow multiple avenues of investigation to be pursued in a coherent and synergistic effort and will result in a better understanding of the systems under investigation as compared with decoupled, independent studies. The proposed methodology also overcomes current limitations on in-situ surface structural studies of nanoscale particles by taking full advantage of recent advances in synchrotron-based surface structural techniques and periodic ab-initio methods. One of the main contributions of this work will be to explain reactivity trends in terms of molecular scale surface structure and nanoscale surface topography/defect density. This will allow the important question of scaling to be addressed since the effects of surface defects on reactivity are anticipated to increase dramatically as particle size decreases to the nanometer scale. This research team is particularly well qualified for an interdisciplinary collaboration aimed at obtaining fundamental information on mineral surface structure and reactivity relevant to the environmental interface chemistry.Broader impacts of the proposed activity: Chemical processes at nanoscale solid/aqueous solution interfaces have far-reaching impacts in environmental chemistry and geochemistry, as well as in various areas of technology that depend on surface reactions, such as heterogeneous catalysis and corrosion control. The work proposed here will lead to improved predictions about metal ion sequestration on (and release from) mineral surfaces, which will ultimately lead to improvements in quantitative models used for assessment of contaminant risk and the design of contaminant remediation strategies. While pursing the technical goals of this project, a major emphasis will be placed on providing educational opportunities to undergraduate, graduate, and post-doctoral students. Student participants will be involved in all aspects of this project, thereby providing research experience in synchrotron-based experimentation, ab-initio electronic structure calculations, and analytical laboratory practices. Thus one of the main impacts of this project will be to produce the next generation of scientists, including women and minorities, who are well trained in the theory and techniques of molecular environmental science, which is highly interdisciplinary and presents major challenges in terms of understanding fundamental chemical processes due to the complexity of environmental systems. Additional educational impact of this work will be reflected in the development of facilities and expertise at the member institutions and by dissemination of results to the broader scientific and general community through peer reviewed publications and presentations.

0404400培训师本提案的重点是对氧化铁表面结构和反应性的分子和纳米级研究的跨学科方法。拟议活动的知识价值：这里提出的研究将利用最先进的实验和理论方法，提供有关铁氧化物反应性基本控制的独特信息。实验使用单晶基板和纳米粒子复合材料的赤铁矿将被用来确定相对于污染物金属离子的吸附反应趋势，以及这些如何变化与表面取向，表面质量，并与“表面改性物种”的反应。所提出的技术的互补性将允许多渠道的调查，以追求在一个连贯和协同的努力，并会导致更好地了解系统的调查相比，脱钩，独立的研究。所提出的方法还克服了目前的局限性，在原位的纳米粒子的表面结构研究，充分利用同步加速器为基础的表面结构技术和周期性从头算方法的最新进展。这项工作的主要贡献之一将是解释反应的分子尺度的表面结构和纳米级的表面形貌/缺陷密度方面的趋势。这将允许解决缩放的重要问题，因为表面缺陷对反应性的影响预计会随着颗粒尺寸减小到纳米尺度而显著增加。该研究小组特别适合开展跨学科合作，目的是获取矿物表面结构和与环境界面化学有关的反应性方面的基本信息。纳米级固/水溶液界面的化学过程在环境化学和地球化学以及依赖于表面反应的各种技术领域中具有深远的影响，例如多相催化和腐蚀控制。这里提出的工作将导致改进的预测金属离子螯合（和释放）矿物表面，这将最终导致改进用于评估污染物的风险和污染物修复策略的设计的定量模型。在追求该项目的技术目标的同时，将重点放在为本科生、研究生和博士后学生提供教育机会上。学生参与者将参与该项目的各个方面，从而提供基于同步加速器的实验，从头计算电子结构计算和分析实验室实践的研究经验。因此，该项目的主要影响之一将是培养下一代科学家，包括妇女和少数民族，他们在分子环境科学的理论和技术方面受过良好的培训，这是一个高度跨学科的领域，由于环境系统的复杂性，在理解基本化学过程方面提出了重大挑战。这项工作的其他教育影响将反映在成员机构设施和专门知识的发展以及通过同行审查的出版物和介绍向更广泛的科学界和一般界传播成果。