Photochemistry at Organic Particle-Air Interfaces

有机颗粒-空气界面的光化学

• 批准号: 0509248
• 负责人: Sergey Nizkorodov
• 金额: $ 34.19万
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0509248&HistoricalAwards=false
• 关键词: Photochemistry; Organic; Particle; Air; Interfaces

The research performed under this project will investigate the mechanisms underlying photochemical processes that occur on the air-solid interfaces of particles in the atmosphere; specifically, those governing the ultraviolet photolysis of organic films that have been partially oxidized by ozone and/or the hydroxyl radical. The principal technique to be used is infrared "cavity ring-down spectroscopy" to detect gas-phase products evolved from the irradiated surfaces. A secondary goal is to study the ozonolysis of unsaturated organics. The results of this research will be applicable to aerosol particles which play a pivotal role in the Earth's atmosphere, from providing a unique heterogeneous environment for chemical reactions to serving as condensation nuclei for cloud formation and efficiently scattering solar radiation. Because aerosol particles are continuously exposed to solar radiation during the daytime, they can potentially serve as media or, in special cases, as catalysts for photochemical processes in the atmosphere.This research will be useful for establishing rational environmental standards for particulate matter in the lower atmosphere, and for improving the predictive power of air pollution and global climate models. Understanding photochemical properties of aerosol particles will help to better predict their atmospheric fates and environmental impacts, and ultimately reduce the risk of population exposure to especially harmful aerosols. This work includes creating a course on air pollution for freshman students, and using the investigator's laboratory instrumentation for training graduate and undergraduate students, providing hands-on training for high school science teachers, and presenting educational seminars to the general public.

在该项目下进行的研究将研究大气中颗粒的空气固定界面上发生的光化学过程的机制。具体而言，那些管理有机膜的紫外线光解的人，这些薄膜已被臭氧和/或羟基自由基部分氧化。要使用的主要技术是红外“腔环光谱”，以检测从辐照表面演变而来的气相产物。次要目标是研究不饱和有机物的臭氧溶解。这项研究的结果将适用于在地球大气中起关键作用的气溶胶颗粒，从为化学反应提供独特的异质环境到作为云形成的凝结核并有效地散射太阳辐射。由于气溶胶颗粒在白天不断暴露于太阳辐射，因此它们可以作为媒介或在特殊情况下作为光化学过程的催化剂，在大气中的光化学过程。这项研究将有助于建立较低大气中颗粒物的合理环境标准，并改善空气污染和全球气候模型的预测能力。了解气溶胶颗粒的光化学特性将有助于更好地预测其大气命运和环境影响，并最终降低人口暴露于特别有害气溶胶的风险。这项工作包括为大一学生创建空气污染课程，并使用调查员的实验室仪器来培训研究生和本科生，为高中科学教师提供动手培训，并向公众举办教育研讨会。