Experimental and Theoretical Studies of Fundamental and Photochemical Processes in Aqueous Environments

水环境中基本和光化学过程的实验和理论研究

• 批准号: 1306386
• 负责人: Veronica Vaida
• 金额: $ 57.29万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-15 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1306386&HistoricalAwards=false
• 关键词: Experimental; Theoretical; Studies; Fundamental; Photochemical

The Environmental Chemical Sciences Program in the Chemistry Division at the National Science Foundation supports the research of Professors Veronica Vaida and Rex T. Skodje both at the University Colorado at Boulder in a collaborative experimental/theoretical effort by their groups that is focused on the study the photochemical reactions of organic molecules occurring at air/water interfaces and in small hydrated clusters in the gas phase. These photochemical reactions can play an important role in the formation and chemical evolution of atmospheric aerosols with potential important consequences to human health and climate change. The intellectual merit in the proposed investigation stems from addressing the basic scientific aspects of sunlight-initiated, water-mediated chemistry of organic molecules. Using a combination of laboratory and theoretical studies, the outcome of the work will be an improved understanding of the mechanisms, dynamics, and rates of photochemical reactions occurring in clusters and on aerosol surfaces that are of importance in the atmosphere. What distinguishes this work from other efforts is the emphasis on deriving molecular-level mechanisms and quantitative models for atmospheric photochemistry in aqueous environments. It is anticipated that greater understanding of the fundamental chemistry involved in the photochemistry occurring in aerosols and more general aqueous environments. An important part of the proposed work is the direct observation of the photochemistry of air/water/organic gas phase mixtures using the French CESAM instrument (Experimental Multiphasic Atmospheric Simulation Chamber). Experiments conducted in this chamber permit the direct observation of aerosol formation and the chemical evolution of the mixture under the influence of intense UV/visible radiation.In terms of broader impacts, improving the ability to model atmospheric processes involved in climate change is an important goal for society and can impact public policy. The treatment of aerosols in current models is a "weak link" and requires significant attention. The proposed study of photochemical mechanisms involved in aerosol nucleation and chemical evolution has the potential to provide improved performance of these models by incorporating a more correct treatment of the chemistry of secondary organic aerosols. In addition, the interdisciplinary, international collaborations proposed will lead to the exchange of students and postdoctoral fellows, and promote cross-fertilization of ideas between different institutions in the basic science of atmospheric photochemistry. The proposed research program contributes to the recruitment, retention and educational development of graduate and undergraduate students, especially from under-represented groups, by exposure to a collaborative and interdisciplinary research environment.

美国国家科学基金会化学部的环境化学科学项目支持Veronica Vaida和雷克斯T.斯科杰都在博尔德的科罗拉多大学，他们的小组合作进行实验/理论工作，重点是研究在空气/水界面和气相中小水合团簇中发生的有机分子的光化学反应。这些光化学反应可在大气气溶胶的形成和化学演变中发挥重要作用，对人类健康和气候变化具有潜在的重要影响。 在拟议的调查的智力价值源于解决阳光引发的，水介导的有机分子化学的基本科学方面。使用实验室和理论研究相结合，工作的结果将是一个更好的理解的机制，动力学，发生在集群和气溶胶表面的光化学反应的速率是在大气中的重要性。这项工作与其他工作的区别在于强调推导水环境中大气光化学的分子水平机制和定量模型。可以预见的是，对气溶胶和更一般的水环境中发生的光化学所涉及的基本化学有了更深入的了解。拟议工作的一个重要组成部分是使用法国CESAM仪器（实验多相大气模拟室）的空气/水/有机气相混合物的光化学的直接观察。在该室中进行的实验可以直接观察气溶胶的形成和混合物在强紫外线/可见光辐射影响下的化学演变，就更广泛的影响而言，提高模拟气候变化所涉及的大气过程的能力是社会的一个重要目标，可以影响公共政策。在目前的模式中，对气溶胶的处理是一个“薄弱环节”，需要给予极大的关注。 所提出的研究涉及气溶胶成核和化学演变的光化学机制有可能提供更好的性能，这些模型纳入一个更正确的处理二次有机气溶胶的化学。此外，提出的跨学科国际合作将导致学生和博士后研究员的交流，并促进不同机构之间在大气光化学基础科学方面的思想交流。拟议的研究计划有助于研究生和本科生的招聘，保留和教育发展，特别是从代表性不足的群体，通过接触到协作和跨学科的研究环境。