Photoactivator Chemistry in Atmospheric Aerosols

大气气溶胶中的光活化剂化学

• 批准号: 1506789
• 负责人: V Faye McNeill
• 金额: $ 51万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1506789&HistoricalAwards=false
• 关键词: Photoactivator; Chemistry; Atmospheric; Aerosols

With this award, the Environmental Chemical Sciences Program of the Division of Chemistry is funding Professor Faye McNeill of Columbia University who, in collaboration with Professors Hai-Lung Dai and Yi Rao of Temple University is investigating photochemical reactions related to atmospheric aerosols. Sunlight is the primary driving force in gas-phase atmospheric chemistry, but the importance of photochemistry occurring inside atmospheric aerosol particles or at the gas-aerosol interface is not well understood. Reactions involving the participation of light-absorbing organic aerosol components as photo-activators have been suggested as pathways for the photochemical origin and processing of important gas-phase species such as NO2 (nitrogen dioxide) and O3 (ozone). This project uses a combination of theory and experiment to investigate chemistry inside aerosols. The PIs have also developed an integrated education and outreach program consisting of three major thrusts: (1) AIRE, a Spanish/English bilingual blog and informational website targeted at students and educators (2) Research and curriculum development with local K-12 science educators, and (3) a teacher certification program designed to train midcareer and early retiree mathematics and science professionals as middle-school teachersThe proposed research is inspired by the hypothesis that photoactivated chemistry involving light-absorbing organic compounds inside atmospheric aerosol particles may lead to the formation of oxidized aerosol organic material, either via the direct oxidation of volatile organic compounds (VOCs) or via the formation of oxidizing radicals in the aerosol phase. This hypothesis is being tested her by a combination of experimental and modeling approaches designed to gain the necessary molecular-level insight into photoactivated aerosol chemistry. Advanced spectroscopic techniques, laser flash photolysis, and computational chemistry will be used to create new knowledge of the systems of interest at the molecular level. Aerosol flow reactor experiments are to be used to quantify the kinetics of these processes under aerosol conditions. The impact of this chemistry in the environmental context is to be evaluated via atmospheric chemistry modeling. This work is expected to provide insight into atmospheric aerosol chemistry with broader scientific impact on the impact of emitted gases upon air composition and derivative properties.

化学系的环境化学科学项目将通过该奖项资助哥伦比亚大学的Faye McNeill教授，他与天普大学的戴海龙教授和饶毅教授合作，正在研究与大气气溶胶相关的光化学反应。阳光是气相大气化学的主要驱动力，但是发生在大气气溶胶颗粒内部或气-气溶胶界面的光化学的重要性还没有得到很好的理解。吸收光的有机气溶胶组分作为光活化剂参与的反应被认为是重要气相物质（如NO2（二氧化氮）和O3（臭氧））的光化学起源和处理的途径。这个项目采用理论和实验相结合的方法来研究气溶胶内部的化学成分。私人机构还制定了一项综合教育和外联方案，其中包括三个主要重点：(1) AIRE，一个针对学生和教育工作者的西班牙语/英语双语博客和信息网站；(2)与当地K-12科学教育工作者进行研究和课程开发；(3)教师认证计划，旨在将职业中期和早期退休的数学和科学专业人员培训为中学教师。该研究的灵感来自于这样一种假设，即大气气溶胶颗粒中涉及光吸收有机化合物的光活化化学可能导致氧化气溶胶有机物质的形成。要么通过挥发性有机化合物（VOCs）的直接氧化，要么通过在气溶胶阶段形成氧化自由基。这一假设正在通过实验和建模方法的结合来验证，旨在获得对光活化气溶胶化学的必要分子水平的了解。先进的光谱技术、激光闪光光解和计算化学将用于在分子水平上创造感兴趣的系统的新知识。气溶胶流动反应器实验将用于量化这些过程在气溶胶条件下的动力学。这种化学对环境的影响将通过大气化学模型加以评估。这项工作有望提供对大气气溶胶化学的深入了解，对排放气体对空气成分和衍生物性质的影响具有更广泛的科学影响。