Photoactivator Chemistry in Atmospheric Aerosols

化学系的环境化学科学项目将为哥伦比亚大学的Faye McNeill教授提供资金，他与坦普尔大学的戴海龙教授和Rao教授合作，研究与大气气溶胶有关的光化学反应。阳光是气相大气化学的主要驱动力，但发生在大气气溶胶颗粒内或气体-气溶胶界面上的光化学的重要性还没有被很好地理解。吸收光的有机气溶胶组分作为光激活剂参与的反应被认为是NO2(二氧化氮)和臭氧(臭氧)等重要气相物种的光化学起源和加工的途径。该项目采用理论和实验相结合的方法来研究气溶胶中的化学物质。PIS还开发了一个由三个主要项目组成的综合教育和推广计划：(1)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科学教育工作者合作的研究和课程开发；以及(3)教师认证计划，旨在培训职业生涯中期和早期退休的数学和科学专业人员担任中学教师。拟议的研究受到一种假设的启发，即大气气溶胶粒子中涉及光吸收有机化合物的光活化化学可能通过挥发性有机化合物(VOC)的直接氧化或通过在气溶胶相中形成氧化自由基来导致氧化的气溶胶有机物质的形成。这一假说正在通过实验和建模相结合的方法进行检验，这些方法旨在获得对光激活气溶胶化学的必要的分子水平的洞察。先进的光谱技术、激光闪光光解和计算化学将被用来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气溶胶条件下这些过程的动力学。这种化学在环境方面的影响将通过大气化学模拟来评估。这项工作预计将对大气气溶胶化学提供洞察，并对排放气体对空气成分和衍生性质的影响产生更广泛的科学影响。

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.