Collaborative Research: RUI: IRES-Track I: Brown Carbon Aerosol Formation by Photooxidation of Phenolic Compounds in Nanodroplets

合作研究：RUI：IRES-Track I：纳米液滴中酚类化合物光氧化形成棕色碳气溶胶

• 批准号: 1826593
• 负责人: David De Haan
• 金额: $ 15.67万
• 依托单位: University of San Diego
• 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: 2018-11-01 至 2023-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1826593&HistoricalAwards=false
• 关键词: Collaborative; Research; RUI; IRES; Track

This IRES project provides experiences for 4-6 undergraduate researchers from the University of San Diego and Harvey Mudd College to spend 8-10 weeks researching brown carbon formation by aqueous photooxidation of atmospheric phenolic compounds. Four weeks of research will be conducted onsite at Universite Paris Est-Creteil (UPEC), where the cohort of undergraduate researchers will closely collaborate with their international mentors on a series of CESAM aerosol chamber experiments utilizing advance spectroscopic methods. After returning from France, the undergraduate research team will focus on the workup, interpretation, and presentation of chamber data, while continuing to interact with international mentors via video conferencing. Each participant will be involved in the project for at least one semester prior and two semesters subsequent to travel for training and further experimentation at their U.S. campuses. In total, 15 undergraduates over 3 years will participate in this international project and will be mentored by French scientists while gaining hands-on experience with advanced research tools. This IRES project is focused on atmospheric chemistry and will contribute to the better understanding of clean air and global warming.Phenolic compounds, which are produced during biomass burning and from the oxidation of anthropogenic aromatic precursors, are believed to be significant sources of brown carbon aerosol when oxidized in cloud droplets, especially in the presence of iron (from dust) or nitrogen oxides (from combustion pollution). However, multi-phase reactions of phenolic compounds have been studied mainly in bulk aqueous solutions rather than in more realistic nanodroplets, where photobleaching can become photobrowning and where reactivity is often accelerated, especially for surface-active oligomerizing species. The researchers will therefore study brown secondary organic aerosol (SOA) formation by phenolic precursor species in nanodroplet "cloud simulation" photooxidation experiments at the CESAM chamber in Paris, characterizing chemical and optical changes in aerosol particles before, during, and after cloud events. Particle browning will be monitored by CAPS-ssa and UV/visible spectroscopy of water-soluble OA as the reactants interact with seed aerosol, water droplets, and simulated sunlight in the pressure, temperature, and RH-controlled chamber. Particle-phase chemistry will be monitored by aerosol mass spectrometry (ACSM-TOF), and particle uptake and outgassing will be detected by high-resolution PTR-MS and long-path FTIR monitoring of gas- phase species. This project will provide 15 diverse U.S. undergraduates with international research experiences at a state-of-the-art cloud chamber facility as the center of a 3-semester research experience for each participant. Project activities will increase understanding of important sources of brown SOA, which will in turn allow this pollutant, and the adverse effects on human health and climate that it causes, to be minimized in a more cost-effective manner.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.

这个IRES项目为来自圣地亚哥大学和哈维穆德学院的4-6名本科生研究人员提供了经验，他们花了8-10周的时间研究大气酚类化合物的水溶液光氧化形成棕色碳。为期四周的研究将在巴黎东克雷泰伊大学（UPEC）现场进行，本科研究人员将与他们的国际导师密切合作，利用先进的光谱方法进行一系列CESAM气溶胶室实验。从法国返回后，本科研究团队将专注于室数据的检查，解释和演示，同时继续通过视频会议与国际导师互动。每个参与者将参与该项目至少一个学期前和两个学期后前往培训和进一步的实验在他们的美国校园。总共有15名3年以上的本科生将参加这个国际项目，并将由法国科学家指导，同时获得先进研究工具的实践经验。该IRES项目的重点是大气化学，将有助于更好地了解清洁空气和全球变暖。酚类化合物，这是在生物质燃烧和人为芳族前体氧化过程中产生的，被认为是褐碳气溶胶的重要来源，当在云滴中氧化时，特别是在铁（来自灰尘）或氮氧化物（来自燃烧污染）的存在下。 然而，酚类化合物的多相反应主要在本体水溶液中而不是在更现实的纳米液滴中进行了研究，其中光漂白可以变成光褐变并且反应性通常被加速，特别是对于表面活性低聚物种。因此，研究人员将在巴黎的CESAM室的纳米液滴“云模拟”光氧化实验中研究酚类前体物质形成棕色二次有机气溶胶（SOA），表征气溶胶颗粒在云事件之前，期间和之后的化学和光学变化。当反应物与种子气溶胶、水滴和模拟阳光在压力、温度和RH控制室中相互作用时，将通过水溶性OA的CAPS-ssa和UV/可见光谱监测颗粒布朗宁。将通过气溶胶质谱法（ACSM-TOF）监测颗粒相化学，并通过气相物质的高分辨率PTR-MS和长光程FTIR监测来检测颗粒吸收和放气。 该项目将为15名不同的美国本科生提供最先进的云室设施的国际研究经验，作为每位参与者3学期研究经验的中心。 项目活动将增加对棕色SOA重要来源的了解，从而使这种污染物及其对人类健康和气候的不利影响以更经济有效的方式最小化。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Elucidating an Atmospheric Brown Carbon Species—Toward Supplanting Chemical Intuition with Exhaustive Enumeration and Machine Learning

阐明大气棕色碳物种——以详尽的枚举和机器学习取代化学直觉

• DOI: 10.1021/acs.est.1c00885
• 发表时间: 2021
• 期刊: Environmental Science & Technology
• 影响因子: 11.4
• 作者: Tapavicza, Enrico;von Rudorff, Guido Falk;De Haan, David O.;Contin, Mario;George, Christian;Riva, Matthieu;von Lilienfeld, O. Anatole
• 通讯作者: von Lilienfeld, O. Anatole