RUI: Chemical phenomena of complex carbonyl-ammonium aqueous aerosol mimics

本科院校研究（RUI）项目的重点是提高对导致大气中棕色碳形成的凝聚相反应的理解。拟议的研究工作将探讨通过羰基化合物和硫酸铵的水溶液反应发生的机理和动力学变化。这项工作包括系统地研究光吸收作为组成的函数，并可能导致改进的预测棕色碳在大气颗粒物中的形成。这项工作包括研究硫酸铵与成对的α-双官能羰基化合物（乙醇醛，乙二醛和甲基乙二醛）的交叉反应，以确定羰基比率和身份对产物形成，棕色碳光吸收和反应速率的影响。本论文的主要工作是回答以下关键科学问题：（1）羰基化合物与铵的交叉反应如何改变产物的组成？(2)产物混合物的光吸收性质如何作为羰基之间的交叉反应的函数而改变？(3)当混合物中添加额外的复杂性时，产物的形成和发色性是如何变化的？本研究将使用超临界流体色谱-质谱和紫外-可见光谱。本科研究生将进行实验室实验，并将参与数据处理和数据展示的各个方面。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 Research in Undergraduate Institutions (RUI) project is focused on improving the understanding of condensed-phase reactions that lead to the formation of brown carbon in the atmosphere. The proposed research effort will explore the mechanistic and kinetic changes that occur through the aqueous reactions of carbonyls and ammonium sulfate. This work includes a systematic study of light absorption as a function of composition and could lead to improved predictions of brown carbon formation in atmospheric particles.This effort involves research on the cross-reactions of ammonium sulfate with paired α-difunctional carbonyls (glycolaldehyde, glyoxal, and methylglyoxal) to determine the effects of carbonyl ratio and identity on product formation, brown carbon light absorption, and reaction rates. The proposed work aims to answer the following key scientific questions: (1) How do cross-reactions of carbonyl compounds with ammonium change product composition? (2) How do light absorption properties of the product mixtures change as a function of cross-reaction between carbonyls? (3) How do product formation and chromophoricity change as additional complexity is added to mixture? Supercritical fluid chromatography-mass spectrometry and UV-visible spectroscopy will be utilized for this study.Undergraduate research students will perform the laboratory experiments and will be involved in all aspects of the data workup and the presentation of the data.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.