Investigating Fundamental Chemical and Physical Processes Affecting Gas-Particle Partitioning Using Levitated Droplet-Mass Spectrometry

使用悬浮液滴质谱法研究影响气体粒子分配的基本化学和物理过程

• 批准号: 1808084
• 负责人: Frank Keutsch
• 金额: $ 58.5万
• 依托单位: Harvard 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 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1808084&HistoricalAwards=false
• 关键词: Investigating; Fundamental; Chemical; Physical; Processes

This award is supported by the Environmental Chemical Sciences Program of the Division of Chemistry. Professor Frank Keutsch of Harvard University and his students investigate the fundamental processes involved in separating compounds between the air and the surface of particles (aerosols) in the atmosphere. This portioning between the air and the surfaces of solids that are present in the air is poorly understood however, one phase may be preferred over the other due to incomplete mixing, physical barriers, and/or chemical reactions on the aerosol particles. Laboratory studies are conducted on single aerosol particles to isolate and investigate how and why compounds stick to their surfaces. These experimental studies provide fundamental parameters for improving computer models on aerosol formation and changes in these particles with time (ageing). This research is important as it may ultimately improve regional and global models of aerosols, which are relevant to air quality and human and animal health. Professor Keutsch also designs laboratory experiments to introduce a systems approach to undergraduate education. This approach considers not only individual reactions but the coupled chemical and physical feedbacks that exist between different parts of the whole system (in this case, the gas and solid phases). His students learn about instrumentation design and reactions at and far from equilibrium. In addition, underrepresented high school students at Cambridge, MA high schools are mentored and work in the research laboratory learning to communicate their research to others in the field and gaining confidence in their abilities to participate in scientific fields. A new approach is used to study aerosol partitioning that combines levitation of individual micron-sized particles with mass-spectrometric (MS) detection. This technique allows the measurement of the molecular-level evolution of a droplet over atmospherically relevant time scales. Molecular-level detection is a novel approach that may advances trapped droplet methods. After further optimization of the trapped-droplet MS, specific research questions related to the role of non-ideal mixing, oligomer formation, transition metal complex photochemistry, and aerosol physical properties in gas-particle partitioning are addressed. This research is done in collaboration with chemists and atmospheric sciences. Results are compared with state-of-the-art models which improve the representation of the fundamental chemical and physical processes in the models, and hence, improve predictive capabilities.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.

该奖项由化学系环境化学科学项目资助。哈佛大学的Frank Keutsch教授和他的学生研究了在空气和大气中颗粒(气溶胶)表面分离化合物所涉及的基本过程。空气和存在于空气中的固体表面之间的这一部分知之甚少，然而，由于气溶胶颗粒上的不完全混合、物理屏障和/或化学反应，其中一相可能比另一相更受欢迎。实验室研究是对单个气溶胶颗粒进行的，以分离和调查化合物如何以及为什么粘在它们的表面。这些实验研究为改进关于气溶胶形成和这些颗粒随时间(老化)变化的计算机模型提供了基本参数。这项研究很重要，因为它可能最终改进与空气质量以及人类和动物健康相关的区域和全球气溶胶模型。Keutsch教授还设计了实验室实验，将系统方法引入本科教育。这种方法不仅考虑了单个反应，而且考虑了整个系统不同部分(在这种情况下，气相和固相)之间存在的耦合的化学和物理反馈。他的学生学习仪器设计和在平衡状态和远离平衡状态时的反应。此外，在马萨诸塞州剑桥的高中，代表人数不足的高中生在研究实验室接受指导和工作，学习如何与该领域的其他人交流他们的研究成果，并获得参与科学领域能力的信心。一种新的方法被用来研究气溶胶分配，它结合了单个微米级颗粒的悬浮和质谱分析(MS)检测。这项技术允许测量液滴在大气相关时间尺度上的分子水平演变。分子水平检测是一种新的方法，它可能会发展捕获液滴的方法。在进一步优化捕获液滴MS的基础上，讨论了非理想混合、低聚物形成、过渡金属络合物光化学和气溶胶物理性质在气粒分配中的作用等具体研究问题。这项研究是与化学家和大气科学合作完成的。结果与最先进的模型进行了比较，这些模型改进了模型中基本化学和物理过程的表示，从而提高了预测能力。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。

项目成果

Revisiting the reaction of dicarbonyls in aerosol proxy solutions containing ammonia: the case of butenedial

重新审视含氨气溶胶代理溶液中二羰基的反应：以丁烯二醛为例

• DOI: 10.5194/acp-21-8809-20
• 发表时间: 2021
• 期刊: Atmospheric chemistry and physics
• 影响因子: 6.3
• 作者: Jack C. Hensley, Adam W.

Single-particle experiments measuring humidity and inorganic salt effects on gas-particle partitioning of butenedial

单颗粒实验测量湿度和无机盐对丁烯二醛气体-颗粒分配的影响

• DOI: 10.5194/acp-19-14195-2019
• 发表时间: 2019
• 期刊: Atmospheric Chemistry and Physics
• 影响因子: 6.3
• 作者: Birdsall, Adam W.;Hensley, Jack C.;Kotowitz, Paige S.;Huisman, Andrew J.;Keutsch, Frank N.
• 通讯作者: Keutsch, Frank N.