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。在化学系环境化学科学计划的支持下，南卡罗来纳州大学的Eric P. Vejerano将研究二次有机气溶胶（SOA）中环境持久性自由基（EPFR）的形成。EPFRs是最近确定的一类稳定和持久性污染物，可导致大气颗粒物对健康的某些不利影响。在理解EPFR的来源、性质和形成方面仍然存在知识差距，例如，有机污染物的大气处理在形成EPFR方面的作用。本项目将研究当挥发性有机化合物（VOC）（例如植物和人类活动释放的VOC）与大气氧化剂（例如，臭氧）以形成颗粒。同样令人感兴趣的是可能导致EPFR形成后损失的后续反应。该项目将利用一套分析方法来探测颗粒的变化，并表征粒度分布和浓度。 这一项目的更广泛影响包括提供关于形成EPFR的化学品类别的知识，将EPFR研究与大气化学结合起来。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，并让他们了解科学，技术，工程和数学（STEM）的职业道路。PI寻求通过多样性培养卓越，并致力于培养来自化学代表性不足的群体的学生。 具体而言，PI正在积极培训职业早期女性和非洲裔美国学生，以加强化学研究的多样性，公平性和包容性。导致VOC转化为SOA的大气过程是EPFR的潜在重要贡献者，因为许多人为和生物源VOC及其氧化副产物具有与已知从主要排放源形成EPFR的化学结构相似的化学结构。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形成并识别可能的化学结构。不同化学类别的挥发性有机化合物将测试其形成EPFR的能力，使用潜在的气溶胶质量室，以探索结构-EPFR的关系。 此外，将探讨种子颗粒，温度，辐照和湿度的影响，通过随后的大气过程调节EPFRs的形成和损失。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VOC转化为SOA，随后形成EPFR的影响;（2）确定影响EPFR形成和损失的因素;以及（3）将研究成果纳入实施教育和推广计划，通过开发电子技术来改善研究主题的科学教育该奖项反映了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 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.