Collaborative Research: Evolution and Impact of Aerosol Phase and Morphology

合作研究：气溶胶相和形态的演变和影响

• 批准号: 1916758
• 负责人: Miriam Freedman
• 金额: $ 29.97万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1916758&HistoricalAwards=false
• 关键词: Collaborative; Research; Evolution; Impact; Aerosol

This project includes both experimental and modeling studies to investigate processes that occur during the formation and aging of small particles in the atmosphere. Small organic particles can separate into liquid phases that then can change the subsequent chemistry of the atmosphere. Experiments will be conducted to study how particle properties such as size, shape, and composition affect particle phase separation. Models will be used to study the impacts these particles have on the atmosphere.The hypothesis of the project is that the liquid-liquid phase separation (LLPS) process is governed by the molecular composition of the particle and the particle size. This hypothesis will be tested using secondary organic aerosol (SOA) produced from the dark ozonolysis of alpha-pined and the photooxidation of 1,2,4-trimethylbenzene in a flow reactor. Particles will be collected, and their morphology will be analyzed by cryotransmission electron microscopy. The research questions that will be addressed by the proposal are the following: (1) What particle-level parameters (O:C, organic:sulfate ratio, size, etc.) determine particle morphology? (2) How does the morphology of aerosol particles evolve in time? Specifically, how do the size of particles and aging influence particle morphology? and (3) What is the impact of aerosol morphology on aerosol processes such as heterogeneous N2O5 hydrolysis? A particle-resolved modeling framework will make use of the experimental results and integrate them to quantify the relevance of the findings for atmospheric chemistry.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.

该项目包括实验和模型研究，以调查大气中小颗粒形成和老化过程中发生的过程。小的有机颗粒可以分离成液相，然后可以改变随后的大气化学。实验将研究颗粒的性质，如大小、形状和组成如何影响颗粒相分离。模型将用于研究这些粒子对大气的影响。该项目的假设是液-液相分离（LLPS）过程受颗粒的分子组成和颗粒大小的控制。这一假设将在流动反应器中使用由α -松木的暗臭氧分解和1,2,4-三甲基苯的光氧化产生的二次有机气溶胶（SOA）进行测试。将收集颗粒，并用低温透射电子显微镜分析其形态。该提案将解决的研究问题如下：(1)什么颗粒水平参数（O:C，有机：硫酸盐比例，大小等）决定颗粒形态？(2)气溶胶粒子的形态如何随时间演变？具体来说，颗粒的大小和老化是如何影响颗粒形态的？(3)气溶胶形态对非均相N2O5水解等气溶胶过程有何影响？粒子分辨模型框架将利用实验结果并将它们整合起来，以量化这些发现与大气化学的相关性。该奖项反映了美国国家科学基金会的法定使命，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

Morphology of Organic/Inorganic Aerosol with Varying Seed Particle Water Content

• DOI: 10.1021/acsearthspacechem.3c00202
• 发表时间: 2023-09
• 期刊: ACS Earth and Space Chemistry
• 影响因子: 3.4
• 作者: Emma C. Tackman;Devon N. Higgins;Murray V. Johnston;M. Freedman

Direct measurement of the pH of aerosol particles using carbon quantum dots

使用碳量子点直接测量气溶胶颗粒的 pH 值

• DOI: 10.1039/d2ay01005d
• 发表时间: 2022
• 期刊: Analytical Methods
• 影响因子: 3.1
• 作者: Tackman, Emma C.;Grady, Rachel S.;Freedman, Miriam Arak
• 通讯作者: Freedman, Miriam Arak

The use of transmission electron microscopy with scanning mobility particle size spectrometry for an enhanced understanding of the physical characteristics of aerosol particles generated with a flow tube reactor

• DOI: 10.1080/02786826.2023.2173999
• 发表时间: 2023-01
• 期刊: Aerosol Science and Technology
• 影响因子: 5.2
• 作者: Emma C. Tackman;Devon N. Higgins;Devan E. Kerecman;Emily-Jean E. Ott;M. Johnston;M. Freedman