Project 6. Structure and Properties of Metal Oxide Particle-Adsorbate Systems

项目 6. 金属氧化物颗粒吸附物体系的结构和性能

• 批准号: 8379662
• 负责人: ERWIN D POLIAKOFF
• 金额: $ 25.07万
• 依托单位: LOUISIANA STATE UNIV A&M COL BATON ROUGE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8379662
• 关键词: Affect; Animals; Aromatic Hydrocarbons; Benign; Binding; Biochemical; Breathing; Characteristics; Chemicals; Chemistry; Collaborations; Complex; Copper; Data; Dose; Electron Transport; Electronics; Electrons; Environment; Free Radical Formation; Free Radicals; Generations; Growth; Health; Hour; Human; Incineration; Investigation; Iron; Lead; Measurement; Mediating; Metals; Methods; Microscopic; Modeling; Molecular; Nanostructures; Nickel; Oxidative Stress; Particulate Matter; Pentachlorophenol; Poison; Pollution; Process; Production; Property; Reaction; Research; Research Personnel; Respiratory System; Roentgen Rays; Role; Seeds; Soil; Soot; Source; Spectrum Analysis; Structure; Superfund; Surface; System; Toxic effect; Transition Elements; Ultrafine; Wood material; Work; X ray spectroscopy; base; density; design; electronic structure; fly ash; innovation; interest; interfacial; metal oxide; molecular dynamics; nanoparticle; particle; planetary Atmosphere; pollutant; research study; superfund site; toxic metal; treatment site; ultrafine particle; wasting

Environmentally persistent free radicals (EPFRs) are formed on surfaces of transition metal oxides when molecules chemisorb on them. Electron transfer from the molecule to the metal results in reduction of the metal and the creation of spin density on the organic molecular adsorbate, i.e., formation of the EPFR. These "interfacial pollutants" are relatively stable (i.e., persisting for hours or days), so they can enter the environment and have deleterious health effects. Moreover, these systems are particularly prevalent at Superfund sites, so it is essential that they be studied and characterized in order to understand their roles in human health impacts in the vicinity of Superfund sites. However, these systems are complex and difficult to characterize, so we have designed this project to understand the detailed structural and chemical transformations that are responsible for their creation. Specifically, this project explores the physical and chemical characteristics of these particle-bound pollutants primarily using x-ray spectroscopy and TEM analysis. There are three Specific Aims: (1) Develop methods for controlled, reproducible generation of metal oxide-containing nanoparticles as surrogates of nanoclusters found in real-world environments, (2) Characterize the metal nanoparticles, structurally and electronically, and (3) Determine the surface processes and interactions of CHCs that lead to the formation of persistent free radicals and other toxic pollutants. This project characterizes the electron properties of the particle surface, which is indispensable for the other projects. Collaboration with Project 1 will lead to understanding of the structure and electronic properties of the EPFRs, which will allow those researchers to understand the factors affecting EPFR formation and reactivity. It generates background for studies of EPFRs in Superfund soils in Project 3. It similarly provides the chemistry necessary to understand the health effects induced by inhalation of EPFRs demonstrated in biomedical projects 2, 4, and 5. Finally, the structural characterization of the metal oxide particles and the surface-bound molecules will be indispensable for both the Computational Core, as well as the Materials Core.

当分子化学吸附在过渡金属氧化物表面时，会在其表面形成环境持久性自由基（EPFR）。电子从分子转移到金属导致金属还原并在有机分子吸附物上产生自旋密度，即形成 EPFR。这些“界面污染物”相对稳定（即持续数小时或数天），因此它们可以进入环境并对健康产生有害影响。此外，这些系统在超级基金地点特别普遍，因此有必要对它们进行研究和表征，以了解它们在超级基金地点附近人类健康影响中的作用。然而，这些系统非常复杂且难以表征，因此我们设计了这个项目来了解导致其产生的详细结构和化学转变。具体来说，该项目主要利用 X 射线光谱和 TEM 分析来探索这些颗粒结合污染物的物理和化学特征。共有三个具体目标：(1) 开发可控、可重复生成含金属氧化物纳米颗粒的方法，作为现实环境中发现的纳米团簇的替代品，(2) 在结构和电子方面表征金属纳米颗粒，(3) 确定CHC 的表面过程和相互作用导致持久性自由基和其他有毒污染物的形成。该项目表征了粒子表面的电子特性，这对于其他项目是不可或缺的。与项目 1 的合作将有助于了解 EPFR 的结构和电子特性，这将使研究人员能够了解影响 EPFR 形成和反应性的因素。它为项目 3 中超级基金土壤中 EPFR 的研究提供了背景。它同样提供了了解生物医学项目 2、4 和 5 中演示的吸入 EPFR 所引起的健康影响所需的化学成分。最后，金属氧化物的结构表征粒子和表面结合分子对于计算核心和材料核心都是不可或缺的。