Environmental Molecular Sciences Laboratory

A DOE Office of Science User Facility

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Probing the Vibrational Coherences of Organic Atmospheric Aerosol Systems

Date: 
Thursday, October 1, 2015
Principal Investigator: 
Franz Geiger
Lead Institution: 
Northwestern University
Closed Date: 
Friday, September 30, 2016
Project ID: 
48842
Abstract: 

This proposal focuses on applying EMSL’s sub-1cm-1-resolution vibrational spectroscopy (hr-SFG) capabilities (Hongfei Wang), solid state NMR spectroscopy (Nancy Washton), nano-DESI high-resolution mass spectrometry analysis techniques (Julia and Alex Laskin), and high-performance computing clusters to improve our molecular-scale understanding of the organic species that are present within and at the surfaces of secondary aerosol (SOA) particles.
The proposed studies described herein are supported by new insights that were recently published with data collected at EMSL’s hr-SFG spectrometer in the group of Hongfei Wang, in Victor Batista’s computational chemistry group at Yale University, in the laboratories of Franz Geiger (SFG) and Regan Thomson (organic synthesis) at Northwestern University, and in Scot Martin’s environmental chamber and flow tube at Harvard University. As part of this proposed project, we will use PNNL’s facilities to test SOA particle properties and formation mechanisms by ‘fast-forwarding’ through chemical reaction pathways proposed by others. Specifically, we will:
A) Analyze the vibrational surface and bulk responses of SOA particle material prepared from the dark ozonolysis of unlabeled and isotope-labeled terpene precursors such as alpha-pinene;
B) Determine the chemical composition and molecular structure of said labeled and unlabeled SOA particle material using solid-state NMR and mass spectrometric responses; and
C) Compare the results to those obtained from synthesized reference compounds, as well as field-derived and size-resolved SOA particles samples from GoAmazon2014/5.