Microstructural Pathway of EPFR Formation and their Decay Mechanisms

项目摘要/摘要：项目5 有强有力的证据表明，环境持久性自由基(EPFR)与部分- 在已申报的和潜在的超级基金地点内/周围发现的Ulate物质(PM)和土壤对环境造成不利影响 对健康的影响。缓解相关的环境风险需要详细了解 受EPFR污染的空气和土壤系统。具体来说，项目5直接与SRP Man保持一致- 日期4，它阐明了减少这些物质的量和毒性的化学和物理方法 危险物质。项目5将研究EPFR的微观或原子特性，以- 信息，包括它们在环境中的显著稳定性，并将模拟由此产生的影响 在广泛的金属氧化物(MO)平台上的化学腐烂。使用了一个工具箱， 不同材料平板上最先进的实验和分子从头计算方法 形式(表面、纳米团簇/粉末、粘土、EPA飞灰、土壤)，我们继续致力于阐明 有机物质的个别细节和相应的局部效应(电子/化学/原子结构) 分子-金属氧化物/中心化学吸附，随后的电荷转移(氧化还原)，以及随后的化学. 与含EPFR的体系(如PM、粉末、粘土和真实世界)相关的CAL降解 (现场EPFR)材料。我们的目标集中在原子水平上回答三个简单的问题：1) EPFR是如何在化学上形成的？2)是什么导致EPFR衰变？以及3)为什么EPFR属性类似于- 跨不同平台的Lar？虽然我们之前的努力已经阐明了EPFR形成的趋势， EPFR衰变机制、寿命和对MO依赖之间的联系--通向 不稳定/补救(SRP任务4)--尚未解决，这是我们 项目。尽管我们的项目主要专注于揭示基础环境科学，但我们的项目将 与该中心共生合作。通过从我们的其他SRP项目中确定物质因素并 将不同材料平台的结果关联起来，我们将获得协同/对抗的趋势 转化为其他项目的EPFR不稳定/补救参数，进而启动 并澄清缓解和补救战略。通过使用实验过程，既可以 模拟和概括真实世界的暴露，项目5将提供微观系统的图片- 产生EPFR和相关吸附系统的TEM，但更重要的是，将询问EF- 促进/阻碍降解的因子以及相应的影响和增强 整个中心的活动(项目1-4和所有核心)。与紧密结合并通过以下方式扩展 项目4，这将使我们的中心能够协同阐明EPFR的原子机制 以可扩展和可预测的方式进行化学，有助于了解生化健康 这些颗粒结合污染物在超级基金站点的影响、缓解和补救。

Project Summary/Abstract: Project 5 There is strong evidence that environmentally persistent free radicals (EPFRs) associated with partic- ulate matter (PM) and soils found in/around declared and potential Superfund sites pose adverse health effects. Mitigation of the associated environmental risks requires a detailed understanding of EPFR-contaminated air and soil systems. Specifically, Project 5 is in direct alignment with SRP Man- date 4, which is elucidating chemical and physical methods to reduce the amount and toxicity of these hazardous substances. Project 5 will study the microscopic, or atomistic, properties of EPFR for- mation, including their remarkable stability in the environment, and will model the resulting influences of chemical decay on a broad base of metal oxide (MO) platforms. Employing a toolbox of state-of- the-art experimental and molecular ab initio computational methods across differing material plat- forms (surfaces, nanoclusters/powders, clays, EPA fly ash, soil), our continued focus is on elucidating individual details of and corresponding local effects (electronic/chemical/atomic structure) on organic molecular-metal oxide/center chemisorption, ensuing charge transfer (redox), and consequent chemi- cal degradation pertinent to EPFR-containing systems such as PM, powders, clays, and real-world (field EPFR) materials. Our Aims focus on answering three simple questions at an atomistic level: 1) How do EPFRs chemically form? 2) What causes EPFR decay? and 3) Why are EPFR properties simi- lar across differing platforms? While our previous efforts have elucidated trends in EPFR formation, the connection between EPFR decay mechanisms, lifetimes, and dependence on MO—the path to destabilization/remediation (SRP Mandate 4)—has not yet been addressed and is a main goal of our project. Although focused primarily on revealing fundamental environmental science, our Project will work symbiotically with the Center. By identifying material factors from our other SRP Projects and correlating results across differing material platforms, we will obtain synergistic/antagonistic tendency parameters for EPFR destabilization/remediation that translate to other Projects, and in turn, initiate and clarify mitigation and remediation strategies. By employing experimental processes that both model and recapitulate real world exposures, Project 5 will provide a picture of the microscopic sys- tems generating the EPFRs and related adsorbate systems, but more importantly, will interrogate ef- fects that promote/hinder degradation and the corresponding products that influence and enhance activities across the Center (Projects 1–4 and all the Cores). Integrating closely with and expanded by Project 4, this will allow our Center to synergistically elucidate the atomic mechanisms of the EPFR chemistry in a scalable and predictive manner that contributes to understanding biochemical health effects, mitigation, and remediation of these particle-bound pollutants at Superfund sites.