Collaborative Research: Organosulfate Multiphase Chemistry and Physicochemcal Properties--Oxidation and Sulfate Recycling in Aerosols and Cloud Droplets

该项目解决了对导致大气中颗粒有机硫酸盐形成的机制途径的理解上的差距。 将进行实验室研究，以检查气态异戊二烯环氧二醇的命运，并研究这些反应的产物如何改变大气气溶胶的性质。 这些研究的结果将有助于改进对空气质量和气候模型中二次有机气溶胶形成的预测。该项目的目标包括研究：（1）异戊二烯环氧二醇（IEPOX）衍生的低挥发性颗粒有机硫酸盐（OS）的非均相羟基自由基（OH）氧化，以了解相对湿度（RH）、预先存在的气溶胶成分（包括pH）和OH暴露如何改变白天OS成分和物理化学性质； (2) IEPOX 衍生 OS 的异质硝酸盐 (NO3) 氧化，以了解相对湿度、预先存在的气溶胶成分（包括 pH）和 NO3 暴露如何改变夜间 OS 成分和理化性质； (3) 云水氧化实验，以了解颗粒物 IEPOX 衍生的 OS 如何回收无机硫酸盐以产生多功能 OS，从而在云滴蒸发时产生水性二次有机气溶胶 (SOA)。该项目包括通过 NSF 资助的青年参与弹性科学计划和 NIH 资助的北卡罗来纳大学 21 世纪环境健康学者计划以及底特律研究实习和暑期体验向高中生开展外展活动密歇根大学 (D-RISE) 计划。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 project addresses a gap in the understanding of mechanistic pathways that lead to the formation of particulate organosulfates in the atmosphere. Laboratory studies will be conducted to examine the fate of gaseous isoprene epoxydiols and to study how the products of these reactions might alter the properties of atmospheric aerosol. The results of these studies will help to improve predictions of the formation of secondary organic aerosol in both air quality and climate models.The objectives of this project include the study of: (1) heterogeneous hydroxyl radical (OH) oxidation of isoprene epoxydiol- (IEPOX) derived low-volatility particulate organosulfates (OSs) to understand how relative humidity (RH), pre-existing aerosol composition (including pH), and OH exposure alter daytime OS composition and physicochemical properties; (2) heterogeneous nitrate (NO3) oxidation of IEPOX-derived OSs to understand how RH, pre-existing aerosol composition (including pH), and NO3 exposure alter nighttime OS composition and physicochemical properties; and (3) cloudwater oxidation experiments to understand how particulate IEPOX-derived OSs recycle inorganic sulfate to yield multifunctional OSs, and thus aqueous secondary organic aerosol (SOA) upon cloud droplet evaporation.This project includes outreach efforts to high school students through the NSF-funded Youth Engaging in the Science of Resilience Program and the NIH-funded 21st Century Environmental Health Scholars Program at the University of North Carolina and through the Detroit Research Internship and Summer Experience (D- RISE) program at the University of Michigan.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.