Probing the Roles of the Surface versus the Bulk in Uptake of Gases Into Atmospherically Relevant Particles

这项研究项目涉及对大气颗粒表面与颗粒整体组成在决定有机气体和水被颗粒吸收中的作用的调查。这项研究的具体目标是：(1)使用本实验室最近实施的尖端质谱学技术，检查一系列模型固体有机颗粒在非均相氧化前后的表面和本体组成；(2)当有机物从气相(“外向内”)或从硝酸盐或亚硝酸盐离子光解引起的原位光化学(“内向外”)引发氧化时，探测表面与本体组成的差异；以及(3)测量氧化前后一系列有机物以及水在上述颗粒中的吸收，以建立气体-颗粒相互作用与表面和本体组成之间的分子关系，以及对颗粒生长和吸湿性的影响。将进行一系列实验室实验，以检查氧化前后模型颗粒对一系列有机蒸气的吸收情况。这项工作产生的数据将为改善颗粒物对气候、空气质量和人类健康影响的预测提供关键见解。这一奖项反映了NSF的法定使命，并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，被认为值得支持。

This research project involves an investigation into the role of the atmospheric particle surface versus the particle bulk composition in determining the uptake of organic gases and water into the particle. This information is critical for the development of models to accurately predict the impacts of airborne particles on air quality, visibility and climate.The specific objectives of this research are to: (1) examine the surface and bulk composition of a series of model solid organic particles both before and after heterogeneous oxidation using cutting edge mass spectrometry techniques implemented recently in this laboratory; (2) probe differences in surface vs bulk composition when oxidation of the organic is initiated from the gas phase ("outside in"), or from in-situ photochemistry induced by nitrate or nitrite ion photolysis ("inside out"); and (3) measure uptake of a range of organics as well as water into the above particles, before and after oxidation, in order to establish molecular relationships between gas-particle interactions and surface and bulk composition, and the impacts on particle growth and hygroscopicity. A series of laboratory experiments will be conducted to examine the uptake of a range of organic vapors onto model particles before and after oxidation. The data generated by this effort will provide critical insights to improve predictions of particle impacts on climate, air quality, and human health.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.