CAREER: Reactions of Volatile Organics in Aerosol Articles as a Source of Persistent Free Radicals

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。在化学学部环境化学科学项目的支持下，南卡罗来纳大学的Eric P. Vejerano将研究二次有机气溶胶（SOA）中环境持久性自由基（EPFRs）的形成。epfr是最近确定的一类稳定和持久的污染物，有助于大气颗粒物对健康的一些不利影响。在了解epfr的来源、性质和形成方面仍然存在知识空白，例如，有机污染物的大气处理在epfr形成中的作用。该项目将调查挥发性有机化合物（挥发性有机化合物），例如植物和人类活动释放的挥发性有机化合物，与大气氧化剂（例如臭氧）反应形成颗粒时epfr的形成。同样令人感兴趣的是在epfr形成后可能导致其丢失的后续反应。该项目将利用一套分析方法来探测颗粒的变化，并表征颗粒的大小分布和浓度。该项目的更广泛影响包括提供形成EPFRs的化学物质类别的知识，将EPFRs研究与大气化学相结合。该项目的概念和成果将被纳入为K-12学生开发可公开访问的电子和在线教育工具。此外，该项目将通过参与研究，为本科生提供科学和技术技能，并为他们提供科学、技术、工程和数学（STEM）职业道路的洞察力。PI寻求通过多样性培养卓越，并致力于培训来自化学领域代表性不足的群体的学生。具体来说，PI正在积极培训早期职业女性和非裔美国学生，以加强化学研究的多样性、公平性和包容性。导致VOCs向SOA转化的大气过程是EPFRs的潜在重要贡献者，因为许多人为和生物源性VOCs及其氧化副产物与已知从主要排放源形成EPFRs的化学结构相似。质谱法将用于确定化学特性，电子顺磁共振光谱法将用于测量EPFR的形成并确定可能的化学结构。不同化学类别的挥发性有机化合物将使用潜在的气溶胶质量室来测试它们形成epfr的能力，以探索结构与epfr的关系。此外，还将探讨种子颗粒、温度、辐照和湿度对epfr通过后续大气过程形成和损失的影响。因此，本职业发展计划的目标是：(1)进行实验室规模的室内研究，以了解大气过程在从VOC到SOA的转变过程中的影响，这些过程随后形成epfr；(2)确定影响epfr形成和丧失的因素；(3)通过开发面向K-12学生的电子和在线教育工具，将研究成果整合到实施教育和推广计划中，以改善有关研究课题的科学教育。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).WIth support from the Environmental Chemical Sciences Program in the Division of Chemistry, Eric P. Vejerano at the University of South Carolina will study the formation of environmentally persistent free radicals (EPFRs) in secondary organic aerosols (SOA). EPFRs are a recently identified class of stable and persistent pollutants that contribute to some of the adverse health effects of atmospheric particulate matter. Knowledge gaps on understanding the sources, nature, and formation of EPFRs remain, for instance, the contribution of atmospheric processing of organic contaminants in forming EPFRs. This project will investigate the formation of EPFRs when volatile organic compounds (VOCs), such as those released by plants and from human-related activities, react with atmospheric oxidants (e.g., ozone) to form particles. Also of interest are subsequent reactions that may result in the loss of EPFRs after their formation. The project will utilize a suite of analytical methods to probe changes in the particles and characterize size distributions and concentrations. The broader impacts of this project include providing knowledge of the classes of chemicals responsible for forming EPFRs, which integrates research on EPFRs with atmospheric chemistry. Concepts and results from the project will be incorporated in developing publicly accessible electronic and online educational tools for K-12 students. Additionally, this project will equip undergraduate students with scientific and technical skills through research participation and give them insight to science, technology, engineering, and mathematics (STEM) career paths. The PI seeks to cultivate excellence through diversity and is engaged in training students from groups underrepresented in chemistry. Specifically, the PI is actively training early career female and African-American students tol strengthen diversity, equity, and inclusion in chemistryresearch. The atmospheric processes leading to the conversion of VOCs to SOA are a potentially significant contributor to EPFRs, since many anthropogenic and biogenic VOCs and their oxidation byproducts have similar chemical structures to those known to form EPFRs from primary emission sources. Mass spectrometry will be used to determine chemical identities and electron paramagnetic resonance spectroscopy to measure EPFR formation and identify possible chemical structures. Diverse chemical classes of VOCs will be tested in their ability to form EPFRs using a potential aerosol mass chamber to explore structure-EPFR relationships. In addition, the impact of seed particles, temperature, irradiation, and humidity that regulate the formation and loss of EPFRs via subsequent atmospheric processes will be explored. The objectives of this career-development plan are therefore to: (1) conduct a lab-scale chamber study to understand the impact of atmospheric processes in the transformation of VOC to SOA that subsequently form EPFRs; (2) determine the factors that affect the formation and loss of EPFRs; and (3) integrate the research outcomes in implementing educational and outreach programs to improve science education on the research topic by developing electronic and online educational tools for K-12 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.