RUI: Secondary Organic Aerosol and Brown Carbon Formation from Aldehydes, Ammonium Salts, and Amines

RUI：醛、铵盐和胺形成的二次有机气溶胶和棕碳

• 批准号: 1129002
• 负责人: David De Haan
• 金额: $ 33.75万
• 依托单位: University of San Diego
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-15 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1129002&HistoricalAwards=false
• 关键词: RUI; Secondary; Organic; Aerosol; Brown

This project will characterize atmospheric aqueous-phase chemistry and formation of brown carbon, targeting two compounds: glycolaldehyde and hydroxyacetone. Other common atmospheric aldehydes such as acetaldehyde and formaldehyde, while not expected to form brown carbon, may still form large amounts of secondary organic aerosol (SOA) material via reactions with ammonium salts and amines. In the presence of alpha-dicarbonyls, these compounds can be incorporated into imidazole products, so their SOA-forming potential will be examined with and without alpha-dicarbonyls present. A suite of methods will be used. First, brown carbon formation will be studied by cavity attenuated phase-shift and ultraviolet-visible (UV-Vis) spectroscopy. Product structure will be characterized by proton nuclear magnetic resonance (NMR) spectroscopy and electrospray ionization mass spectrometry. Hygroscopicity tandem differential mobility analysis and Raman microscopy will be used to measure water uptake and surface activity of reaction products. Reaction rates will be measured by NMR and UV-Vis spectroscopies. Aerosol will be generated by three different methods, as required for specific experiments. The aim of these studies will be to identify and characterize reaction products, measure reaction rates and gas/particle partitioning, and determine the atmospheric significance of these SOA and brown carbon formation pathways.At least twenty diverse undergraduate students will be mentored in first research experiences as part of this project, widening the pipeline of students choosing careers in science by offering more student research opportunities, an enhanced research infrastructure, and an increased publication rate of articles with undergraduate co-authors. The addition of a postdoctoral teacher / researcher will allow more students to be mentored while providing excellent training for an early-career scientist. The field will benefit from the characterization of potentially significant sources of SOA and brown carbon, and from the training of a diverse group of young scientists. Finally, a connection between brown carbon formation and ammonia / amine emissions may suggest new avenues for mitigating aerosol formation to improve air quality and address global warming.

该项目将描述大气水相化学和棕色碳的形成，目标是两种化合物：乙醇醛和羟基丙酮。其他常见的大气醛类，如乙醛和甲醛，虽然预计不会形成棕色碳，但仍可能通过与铵盐和胺的反应形成大量的二次有机气溶胶（SOA）材料。在α-二羰基化合物的存在下，这些化合物可以掺入咪唑产品中，因此将在存在和不存在α-二羰基化合物的情况下检查它们的SOA形成潜力。将使用一套方法。首先，将通过腔衰减相移和紫外-可见（UV-Vis）光谱研究棕色碳的形成。将通过质子核磁共振（NMR）光谱和电喷雾电离质谱表征产品结构。吸湿性串联微分迁移率分析和拉曼显微镜将用于测量反应产物的吸水率和表面活性。将通过NMR和UV-Vis光谱测量反应速率。根据具体实验的需要，将通过三种不同的方法产生气溶胶。这些研究的目的将是识别和表征反应产物，测量反应速率和气体/颗粒分配，并确定这些SOA和棕色碳形成途径的大气意义。作为该项目的一部分，至少20名不同的本科生将在第一次研究经验中得到指导，通过提供更多的学生研究机会，拓宽学生选择科学职业的管道，一个增强的研究基础设施，并增加与本科合著者的文章的出版率。增加博士后教师/研究人员将使更多的学生得到指导，同时为早期职业科学家提供良好的培训。该领域将受益于对SOA和棕色碳的潜在重要来源的表征，以及对不同年轻科学家群体的培训。最后，棕色碳形成和氨/胺排放之间的联系可能会提出减少气溶胶形成以改善空气质量和解决全球变暖的新途径。