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Understanding Formation of Condensible Organics from Photochemical Oxidation During New-Particle Formation Experiments

了解新粒子形成实验期间光化学氧化中可凝结有机物的形成

基本信息

批准号：
1801897
负责人：
Neil Donahue
金额：
$ 72.15万
依托单位：
Carnegie-Mellon University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-08-01 至 2021-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1801897&HistoricalAwards=false
关键词：
Understanding Formation Condensible Organics Photochemical

项目摘要

This project focuses on the study of the formation and growth of new particles in the atmosphere. The research will combine collaborative experiments at CERN as part of the Cosmics Leaving OUtdoor Droplets (CLOUD) consortium, with smog-chamber studies at Carnegie Mellon University (CMU). The CLOUD experimental facility is likely the world's most sophisticated experiment addressing atmospheric new-particle formation. It was constructed to measure new particle formation under highly controlled, ultra-clean conditions.At CLOUD, the CMU team will use an iodide chemical ionization mass spectrometer to measure the composition of gases and growing particles, the later by thermal desorption from teflon filters (FIGAERO CIMS). The major objective will be to understand how gas-phase oxidation chemistry makes products with extraordinary low vapor pressures, capable of forming new particles and also condensing on existing particles making them grow. A major focus will be to compare chemical conditions in CLOUD, which more closely resemble the clean background atmosphere, with those in traditional smog chamber experiments, that often exceed those in the most polluted cities. The project will focus on the role of peroxy radical formation and subsequent "auto-oxidation" that can convert semi-volatile peroxy radicals into low-volatility peroxy radicals, and the subsequent termination chemistry that generates condensible products.This research will form the core of two student dissertations. One will focus principally on gas-phase oxidation chemistry, specifically the temperature dependent sources and fate of highly oxidized peroxy radicals that is hypothesized to be at the center of the formation of low-volatility and extremely low-volatility organic compounds. The other will focus on the composition of the condensed phase and the potential for reactive uptake of semivolatile organic compounds to contribute to particle growth. The project results will yield a much better understanding of the rate-limiting elementary steps associated with new-particle formation and growth and competing atmospheric processes that might interfere with those rate-limiting steps.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.

该项目的重点是研究大气中新粒子的形成和生长。这项研究将结合联合收割机在欧洲核子研究中心的合作实验，作为宇宙离开户外液滴（云）财团的一部分，在卡内基梅隆大学（CMU）的烟雾室研究。云实验设施可能是世界上最复杂的实验解决大气新粒子的形成。在CLOUD，CMU团队将使用碘化物化学电离质谱仪测量气体和正在生长的颗粒的组成，后者通过从TECHNOLOGY过滤器（FIGAERO CIMS）的热解吸来测量。主要目标将是了解气相氧化化学如何使产品具有极低的蒸汽压，能够形成新的颗粒，并在现有颗粒上冷凝，使其生长。一个主要的重点将是比较云的化学条件，它更接近于清洁的背景大气，与传统的烟雾室实验，往往超过那些在污染最严重的城市。该项目将集中在过氧自由基的形成和随后的“自动氧化”，可以将半挥发性过氧自由基转化为低挥发性过氧自由基的作用，以及随后的终止化学，产生可冷凝的产品。这项研究将形成两个学生论文的核心。一个将主要集中在气相氧化化学，特别是温度依赖的来源和高度氧化的过氧自由基的命运，被假设为在低挥发性和极低挥发性有机化合物的形成的中心。另一个将集中在凝聚相的组成和潜在的半挥发性有机化合物的反应吸收，以促进颗粒的生长。该项目的结果将产生一个更好地了解与新粒子的形成和增长和竞争的大气过程，可能会干扰这些限速步骤的限速基本步骤。这个奖项反映了NSF的法定使命，并已被认为是值得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的支持。

项目成果

期刊论文数量（21）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Molecular Composition and Volatility of Nucleated Particles from α-Pinene Oxidation between −50 °C and +25 °C

α-蒎烯氧化成核颗粒在 50 °C 至 25 °C 温度下的分子组成和挥发性

DOI：
10.1021/acs.est.9b03265
发表时间：
2019
期刊：
Environmental Science & Technology
影响因子：
11.4
作者：
Ye, Qing;Wang, Mingyi;Hofbauer, Victoria;Stolzenburg, Dominik;Chen, Dexian;Schervish, Meredith;Vogel, Alexander;Mauldin, Roy L.;Baalbaki, Rima;Brilke, Sophia
通讯作者：
Brilke, Sophia

Atmospheric Nanoparticle Survivability Reduction Due to Charge‐Induced Coagulation Scavenging Enhancement