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

这个本科院校研究（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。提出的研究工作将探讨羰基和硫酸铵在水反应中发生的机理和动力学变化。这项工作包括对光吸收作为成分函数的系统研究，并可能导致对大气颗粒中棕色碳形成的改进预测。这项工作包括研究硫酸铵与配对α-双官能团羰基（乙醇醛、乙二醛和甲基乙二醛）的交叉反应，以确定羰基比例和特性对产物形成、棕色碳光吸收和反应速率的影响。提出的工作旨在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特性如何随羰基间的交叉反应而变化？(3)当混合物中加入额外的复杂性时，产物的形成和显色性是如何变化的？本研究将采用超临界流体色谱-质谱法和紫外可见光谱法。本科生将进行实验室实验，并将参与数据整理和数据展示的各个方面。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识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.