Measured Organic Particle Types with Molecular Modeling of their Volatility and Uptake Properties

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。这项研究提出了一种综合的测量，分析和建模方法，解决了三个相关任务中的这些不确定性。 主要研究者（PI）将：（1）收集并分析烟雾室中产生的有机气溶胶的官能团组成和形态使用扫描透射X射线显微镜（STXM）和傅里叶变换红外光谱（FTIR），作为“年龄”的函数，（2）与烟雾室颗粒和其他公开的颗粒类型相比，分析我们在11次现场活动期间收集的大约1000个环境颗粒光谱的档案的形态;以及（3）通过模型模拟识别所观察到的有机化合物类型和形态之间的联系。 对于每种类型，PI还将计算这些颗粒在大气条件下表现出的挥发性和吸水性。 考虑到感兴趣的大气颗粒物尺寸的广泛范围和模拟单个分子的计算限制，这项工作将包括用于小于20纳米的粒子的“全粒子”技术和“板”技术。该项目为两名博士后学者和一名研究生创造了一系列培训机会，他们将参加通过实验和计算方法的参与，科学事业。 这项工作建立了美国三个学术机构之间的新合作。 此外，PI将让学生参与总结我们最近对气溶胶行为的研究结果，以供更广泛的受众在研究人员维护的“外展”网页上发布。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).This research presents a combined measurement, analysis, and modeling approach that addresses these uncertainties in three related tasks. The Principal Investigator (PI) will: (1) collect and analyze organic aerosols generated in smog chambers for functional group composition and morphology (including chemical distribution within individual particles) using Scanning Transmission X-ray Microscopy (STXM) and Fourier Transform Infrared Spectroscopy (FTIR), as a function of "age" (oxidant exposure); (2) analyze the morphology of our archive of approximately 1000 ambient particle spectra collected during eleven field campaigns in comparison to the smog chamber particles and other published particle types; and (3) identify the links between the observed organic compound types and morphologies via model simulations. For each type, the PI will also calculate the volatility and water uptake properties that these particles exhibit in atmospheric conditions. Given the wide range of atmospheric particle sizes of interest and the computational limitations of simulating individual molecules, the work will include "full particle" techniques for particles smaller than 20 nanometers and "slab" techniques for estimating parameters suitable for describing larger particles in atmospheric models.This project creates a set of training opportunities for two postdoctoral scholars and one graduate student who will participate in the scientific enterprise through engagement in experimental and computational methods. The work establishes a new collaboration among three U.S. academic institutions. In addition, the PI will involve students in summarizing our recent findings on aerosol behavior for a broader audience for posting on the "Outreach" web page maintained by the investigators.