AGS-PRF: Characterizing the Physicochemical Properties of Primary and Secondary Ultrafine Particles from Brake Emissions

在这个博士后研究奖学金项目中，PI将加入加州大学欧文分校的一个研究团队，通过实验室实验和基于过滤器的小规模实地活动来研究刹车磨损产生的超细气溶胶排放的特性。刹车磨损造成的气溶胶排放最近被确定为交通部门非尾气相关排放的主要贡献者，随着向电动汽车的不断转变，非尾气排放的相对重要性日益重要。此外，PI还将与当地一个致力于改善空气质量和清洁空气的非营利性组织合作，并与电影制作人合作，制作与这项研究相关的双语(英语和西班牙语)科学教育视频。这项工作包括三个研究问题：(1)断裂磨损形成的超细颗粒的物理化学性质是什么？(2)经过二次大气处理(包括氧化和光降解)后，这些特性是如何变化的？(3)来自加利福尼亚州圣安娜的环境样品中是否存在刹车磨损的超细颗粒？有三种主要的研究方法：(1)关于刹车废气形成超细颗粒的实验室实验；(2)使用氧化流动反应器来表征二次物种的形成；以及(3)在加利福尼亚州圣安娜的过滤器上收集刹车磨损排放产生的超细颗粒，并通过暴露于紫外线辐射来研究它们的化学。该项目将使用多种仪器，包括各种质谱仪和电子显微镜。该奖项反映了NSF的法定使命，通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为是值得支持的。

In this Postdoctoral Research Fellowship project, the PI will join a team of researchers at the University of California Irvine in order to study the properties of ultrafine aerosol emissions from brake wear via laboratory experiments and a small-scale filter-based field campaign. Aerosol emissions from brake wear has recently been identified as a major contributor to non-exhaust related emissions from the transportation sector and with the ongoing shift to electric vehicles, the relative important of non-exhaust emissions are of growing importance. The PI will additionally collaborate with a local nonprofit organization working towards improved air quality and cleaner air as well as collaborate with filmmakers in order to produce bilingual (English and Spanish) science education videos related to this research. The work includes three research questions: (1) What are the physiochemical properties of ultrafine particles formed from break wear? (2) How do these properties change after undergoing secondary atmospheric processing including oxidation and photodegradation? (3) Are ultrafine particles from brake wear present in ambient samples from Santa Ana, California? There are three main research approaches: (1) laboratory experiments on the formation of ultrafine particles from brake emissions; (2) the use of an oxidation flow reactor to characterize the formation of secondary species; and (3) the collection of ultrafine particles generated from brake wear emissions on filters within Santa Ana, California, and the study of their chemistry via exposure to ultraviolet radiation. Multiple instruments will be used during this project including various mass spectrometers as well as a transmission electron microscope.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.