ERI: Direct Photochemistry Effects on Carbonyl/Ammonium-derived Aqueous Secondary Organic Aerosol

该奖项全部或部分由《2021年美国救援计划法案》（公法117-2）资助。气溶胶通过与阳光的相互作用和形成云，对空气质量、人类健康和地球气候产生重大影响。大多数大气气溶胶是二次有机气溶胶（SOA），通过挥发性有机化合物的氧化，然后在气溶胶凝聚相颗粒物质中分配而形成。含羰基的挥发性有机化合物（CVOCs）是SOA的重要贡献者。然而，CVOCs光化学对SOA的大小、组成和物理性质的影响尚不清楚。这个ERI项目的首要目标是解决这个知识差距。为了实现这一目标，首席研究员（PI）和他的团队将在不同的阳光照射下测量covc衍生的SOA水溶液的表面张力、光吸收率和组成。这项计划的成功完成，将透过发展有关悬浮微粒对空气质素、云的形成及气候变化的影响的新基础知识，造福社会。进一步的社会效益将通过学生教育和培训来实现，包括在拉斐特学院指导两名本科生。含羰基的挥发性有机化合物（CVOCs）如乙二醛和甲基乙二醛及其反应产物是二次有机气溶胶（SOA）水溶液形成的重要贡献者。这个ERI项目的首要目标是促进对CVOCs的体积和表面水性光化学的基本理解，以及它对SOA水溶液的大小、组成和物理性质的影响。为了实现这一目标，PI和他的团队建议围绕三个任务进行一个综合实验计划。任务1将通过增加UV灯阵列来修改Lafayette连续流大气室，使SOA水溶液能够在受控的相对湿度条件下暴露于不同量的辐射中。任务2将测量SOA解决方案的尺寸分布、组成和表面张力的变化，使用挥发性有机化合物的雾化水混合物作为模型系统。任务3将分析收集的数据，并将任务2中测量的物理/化学性质的变化与类似的散装溶液和液滴样品的变化进行比较。这项研究的成功完成有可能推进我们对SoA水溶液的形成和物理/化学性质及其对空气质量、云的形成、辐射强迫和气候变化的影响的基本理解。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 award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).Aerosols have a significant impact on air quality, human health, and Earth’s climate via interactions with sunlight and in forming clouds. Most atmospheric aerosols are secondary organic aerosols(SOA), formed via the oxidation of volatile organic compounds followed by partitioning in the aerosol condensed phase particulate matter. Carbonyl-containing volatile organic compounds (CVOCs) are significant contributors to SOA. However, the impact of photochemistry of CVOCs on the size, composition and physical properties of SOA is not well understood. The overarching goal of this ERI project is to address this knowledge gap. To achieve this goal, the Principal Investigator (PI) and his team will measure the surface tension, light absorbance, and compositions of COVC-derived aqueous SOA solutions under varying amounts of sunlight. The successful completion of this project will benefit society through the development of new fundamental knowledge on the impact of aerosols on air quality, cloud formation, and climate change. Further benefits to society will be achieved through student education and training including the mentoring of two undergraduate students at Lafayette College. Carbonyl-containing volatile organic compounds (CVOCs) such as glyoxal and methylglyoxal and their reactive products are significant contributors to the formation of aqueous solutions of secondary organic aerosol (SOA). The overarching goal of this ERI project is to advance the fundamental understanding of the bulk and surface aqueous photochemistry of CVOCs and its impacts on the size, composition, and physical properties of aqueous solutions of SOA. To advance this goal, the PI and his team propose to carry out an integrated experimental program structured around three tasks. Task 1 will modify the Lafayette continuous-flow atmospheric chamber though the addition of UV lamp arrays to enable the exposure of aqueous SOA solutions to varying amounts of radiation under controlled relative humidity conditions. Task 2 will measure changes in the size distribution, composition, and surface tension of SOA solutions using aerosolized aqueous mixtures of CVOCs as model systems. Task 3 will analyze the collected data and compare the changes in the physical/chemical properties measured in Task 2 to those from analogous bulk solution and droplet samples. The successful completion of this research has the potential to advance our fundamental understanding of the formation and physical/chemical properties of aqueous SoA solutions and their impact on air quality, cloud formation, radiative forcing, and climate change.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.