Chemical Imaging Studies of Liquid-Liquid Phase Separation in Atmospheric Aerosols
EMSL Project ID
47937
Abstract
A large fraction of atmospheric aerosols contain an internal mixture of organics and inorganic salts. As the relative humidity (RH) cycles in the atmosphere, these particles can undergo phase transitions including liquid-liquid phase separation. If phase separation occurs, the optical properties and the reactive uptake of gaseous species may be affected, with important impacts on climate predictions. The occurrence and characteristics of liquid-liquid phase separations is uncertain in part due to a lack of observations of ambient samples. Here, chemical imaging techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM), and scanning Transmission X-Ray Microscopy (STXM) will be used to characterize the phase changes of laboratory generated and ambient aerosols at different RH's and to quantify the extent of phase separation of micron and submicron particles. These measurements will increase understanding of physical processes in aerosols and will reduce the uncertainties due to aerosols in climate models.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2013-10-01
End Date
2015-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Co-Investigator(s)
Team Members
Related Publications
Knopf DA, PA Alpert, B Wang, RE O'Brien, ST Kelly, A Laskin, MK Gilles, and RC Moffet. 2014. "Micro-Spectroscopic Imaging and Characterization of Individually Identified Ice Nucleating Particles from a Case Field Study." Journal of Geophysical Research. D. (Atmospheres) 119:10,365-10,381. doi:10.1002/2014JD021866
O'Brien RE, A Neu, SA Epstein, A MacMillan, B Wang, ST Kelly, S Nizkorodov, A Laskin, RC Moffet, and MK Gilles. 2014. "Phase State and Physical Properties of Ambient and Laboratory Generated Secondary Organic Aerosol ." Geophysical Research Letters [epub ahead of print]:, doi:10.1002/2014GL060219