Condensed-Phase Organic Photochemistry in Aerosol Particles and in Aerosol Liquid Water

该项目包括一些实验室实验，以研究暴露在阳光下的大气中小颗粒的命运。 暴露在阳光下会导致颗粒物发生化学变化，从而缩短其在大气中的寿命。 本研究的目的是：（1）系统地研究二次有机气溶胶（SOA）光降解速率与SOA类型和SOA形成条件的关系;（2）研究模拟气溶胶液态水条件的高浓度无机电解质溶液中SOA的光化学;（3）研究直接和间接光化学过程在辐照SOA中的相对重要性;（4）研究生物质的光降解和光敏化过程。燃烧有机气溶胶。这些实验的结果将用于模拟大气有机颗粒内部发生的光化学反应的影响以及云滴内部含有溶解有机物对全球大气中有机气溶胶的影响。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project includes a number of laboratory experiments to study the fate of small particles exposed to sunlight in the atmosphere. Exposure to sunlight can cause chemical changes in the particles that reduces their atmospheric lifetimes. This research will provide valuable information for predicting the fate of aged organic particulate matter and is relevant to understanding the health effects of fine particles in the atmosphere.The objectives of this research are to: (1) systematically explore the dependence of secondary organic aerosol (SOA) photodegradation rates on the type of SOA and on the conditions of SOA formation; (2) investigate photochemistry of SOA in highly concentrated solutions of inorganic electrolytes mimicking the conditions found in aerosol liquid water; (3) investigate the relative importance of direct and indirect photochemical processes in irradiated SOA; and (4) investigate photodegradation and photosensitization processes in biomass-burning organic aerosols.The results of these experiments will be used to model the effects of photochemical reactions occurring inside atmospheric organic particles and inside cloud droplets containing dissolved organics on the global atmospheric burden of organic aerosol. This effort will directly support the training of at least two graduate students and at least six undergraduate students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.