New Particle Formation Experiments: Nucleation and Growth

新的粒子形成实验：成核和生长

• 批准号: 1761638
• 负责人: David Hanson
• 金额: $ 38.41万
• 依托单位: Augsburg 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: 2018-06-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1761638&HistoricalAwards=false
• 关键词: New; Particle; Formation; Experiments; Nucleation

This project focuses on the formation and growth of new particles in the atmosphere. Laboratory experiments will be conducted to measure changes in the rate of new particle formation and growth with changes in composition, temperature, and relative humidity. The results are expected to lead to improved accuracy in predicting the impacts of new particle formation on climate, health and visibility.Laboratory research includes experiments to: (1) conduct measurements of nucleation rates in the ammonia - H2SO4 system as a function of reagent concentrations and temperature; (2) conduct measurements of the synergistic effect of ammonia on nucleation rates for the amine - H2SO4 system at low H2SO4 concentrations; (3) characterize growth rates using a Photolytic Flow Reactor with growth via H2SO4 and using a second flow reactor with growth agents injected in the vapor phase; (4) measure the nanoparticle size-dependency of the growth capabilities of select organic compounds; (5) estimate absolute growth rates (i.e., uptake efficiency) by incorporating measured gas-phase concentrations into model simulations; and (6) explore the capability of the Photolytic Flow Reactor as a tool for understanding growth via uptake of complex secondary oxidation products such as are produced in photo-oxidation of alpha-pinene.The Principal Investigator (PI) plans to use computational fluid dynamics (CFD) simulations of the flow reactor to bolster the interpretation of the experimental results. The CFD simulations allow for estimates of the free energies of small molecular clusters and extrapolations of the results to conditions in other experiments so that nucleation rates can be compared. The PI intends to compare the results from this project with global atmospheric particle formation measurements from the CERN CLOUD project.The project will help develop undergraduate research capabilities by exposing undergraduates to high-level experimental and computational work that will prepare them for careers in science.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.

这个项目的重点是大气中新粒子的形成和生长。将进行实验室实验，以测量新颗粒形成和生长速度随成分、温度和相对湿度变化的变化。研究结果有望提高预测新粒子形成对气候、健康和能见度影响的准确性。实验室研究包括以下实验：(1)测量氨- H2SO4体系的成核速率随试剂浓度和温度的变化；(2)在低H2SO4浓度下测定氨对胺- H2SO4体系成核速率的协同效应；(3)通过H2SO4生长的光解流反应器和在气相注入生长剂的第二流反应器来表征生长速率；(4)测定所选有机化合物生长能力的纳米粒径依赖性；(5)通过将测量的气相浓度纳入模型模拟，估计绝对增长率（即吸收效率）；(6)探索光解流动反应器作为一种工具的能力，以了解通过吸收复杂的二次氧化产物（如α -蒎烯的光氧化产生的产物）来生长的能力。首席研究员（PI）计划使用流动反应器的计算流体动力学（CFD）模拟来支持对实验结果的解释。CFD模拟允许估计小分子簇的自由能，并将结果外推到其他实验中的条件，以便可以比较成核速率。PI打算将这个项目的结果与CERN CLOUD项目的全球大气粒子形成测量结果进行比较。该项目将通过让本科生接触高水平的实验和计算工作，为他们在科学领域的职业生涯做准备，从而帮助培养本科生的研究能力。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

Measurement report: Sulfuric acid nucleation and experimental conditions in a photolytic flow reactor

测量报告：光解流反应器中的硫酸成核和实验条件

• DOI: 10.5194/acp-21-1987-2021
• 发表时间: 2021
• 期刊: Atmospheric Chemistry and Physics
• 影响因子: 6.3
• 作者: Hanson, David R.;Menheer, Seakh;Wentzel, Michael;Kunz, Joan
• 通讯作者: Kunz, Joan

H 2 SO 4 and particle production in a photolytic flow reactor: chemical modeling, cluster thermodynamics and contamination issues

H 2 SO 4 和光解流反应器中的颗粒产生：化学建模、团簇热力学和污染问题

• DOI: 10.5194/acp-19-8999-2019
• 发表时间: 2019
• 期刊: Atmospheric Chemistry and Physics
• 影响因子: 6.3
• 作者: Hanson, David R.;Abdullahi, Hussein;Menheer, Seakh;Vences, Joaquin;Alves, Michael R.;Kunz, Joan
• 通讯作者: Kunz, Joan

Semiempirical H 2 SO 4 –H 2 O Cluster Standard Gibbs Reaction Energies from Nucleation Experiments: Improved Temperature Dependence

成核实验中的半经验 H 2 SO 4 →H 2 O 簇标准吉布斯反应能量：改进的温度依赖性

• DOI: 10.1021/acs.jpca.2c04737
• 发表时间: 2022
• 期刊: The Journal of Physical Chemistry A
• 作者: Hanson, David R.;Case, Amanda S.
• 通讯作者: Case, Amanda S.

Particle Formation from Photooxidation of αpinene, Limonene, and Myrcene

α蒎烯、柠檬烯和月桂烯的光氧化形成颗粒

• DOI: 10.1021/acs.jpca.1c08427
• 发表时间: 2022
• 期刊: The Journal of Physical Chemistry A
• 作者: Hanson, David R.;Sawyer, Adam;Long, Darlene;Sofio, Dominick;Kunz, Joan;Wentzel, Michael
• 通讯作者: Wentzel, Michael

Effects of Precursor Structure on First-Generation Photo-Oxidation Organic Aerosol Formation

• DOI: 10.3389/fenvs.2022.892389
• 发表时间: 2022-06
• 作者: D. Sofio;D. Long;T. Kohls;J. Kunz;M. Wentzel;D. Hanson