Photochemistry of Secondary Organic Aerosol

二次有机气溶胶的光化学

• 批准号: 0831518
• 负责人: Sergey Nizkorodov
• 金额: $ 44.78万
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0831518&HistoricalAwards=false
• 关键词: Photochemistry; Secondary; Organic; Aerosol

The focus of this project is on providing a molecular level understanding of photochemical reactions occurring inside secondary organic aerosol (SOA) particles. SOA contributes to both direct and indirect radiative forcing of climate, and affects air quality in the urban and remote atmosphere. The primary goal of this research is to understand the photochemical processing of SOA derived from the oxidation of isoprene and selected monoterpenes by ozone or the nitrate radical (NO3). To achieve this goal, model SOA will be prepared and the absorption spectra and photodissociation spectra of the resulting SOA material will be investigated using the method of aerosol photodissociation spectroscopy. In parallel, the composition of model terpene SOA will be analyzed in detail using ultrahigh-resolution mass spectrometry before and after the SOA is exposed to simulated solar radiation. In addition, absolute quantum yields for photolysis of several model carbonyls embedded in SOA-like materials will be measured. This information will be used to estimate rates of photochemical reactions occurring inside atmospheric SOA particles.The interaction between solar radiation and organic materials is directly relevant to several areas of research, including the photodegradation of organic polymers and coatings, photochemistry of soil organics and dissolved organic matter, organic photochemistry, and water purification. This research will also provide information useful for predicting the health effects of aged organic particulate matter. Two graduate students will be supported through this award.

该项目的重点是提供对次生有机气溶胶（SOA）颗粒内部的光化学反应的分子水平理解。 SOA有助于直接和间接的辐射强迫气候，并影响城市和偏远大气的空气质量。 这项研究的主要目的是了解源自异戊二烯的氧化和通过臭氧或硝酸盐自由基（NO3）选择的单萜的光化学处理。 为了实现这一目标，将制备模型SOA，并将使用气溶胶光解离光谱法研究所得SOA材料的吸收光谱和光解异光谱。 同时，将使用超高分辨率的质谱法对SOA暴露于模拟太阳辐射之前和之后进行详细分析模型SOA的组成。 此外，将测量嵌入在SOA样材料中的几种模型羰基光解的绝对量子产率。 该信息将用于估计大气SOA颗粒内发生的光化学反应的速率。太阳辐射与有机材料之间的相互作用与几个研究领域直接相关，包括有机聚合物和涂层的光降解，土壤有机物的光化学，土壤有机物的光化学，有机物物质，有机光学化学和水含水量。 这项研究还将提供用于预测老化有机颗粒物的健康影响的信息。 该奖项将获得两名研究生的支持。