AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Deliquescence and Hygroscopic Properties of Organosulfates
ARMANDO ESTILLORE, Anusha Priyadarshani Silva Hettiyadura, Zhen Qin, Timothy Humphry, Vicki Grassian, Elizabeth Stone, University of Iowa
Abstract Number: 671 Working Group: Aerosol Chemistry
Abstract Organosulfates (OS) are important secondary organic aerosol (SOA) that have been identified in numerous field studies. This class of SOA can potentially affect aerosol physicochemical properties such hygroscopicity because of their acidic and amphiphilic nature. Currently, there is a dearth of information on how aerosol particles that contain OS interact with water vapor in the atmosphere. Herein we report laboratory investigations on the hygroscopic properties of several OS salts using Hygroscopicity-Tandem Differential Mobility Analyzer (H-TDMA) at varying relative humidity (RH). The OS studied include the potassium salts of: glycolic acid sulfate, hydroxyacetone sulfate, benzylsulfate, methyl-, ethyl-, propyl-, epoxybutanol-, and butenediol sulfate. In addition, mixtures of OS and sodium chloride were also studied. The results showed continuous uptake and evaporation of water in both hydration and dehydration processes for the OS while the mixture showed prompt deliquescence (DRH) and effloresce (ERH) point, albeit at a lower DRH and ERH relative to pure sodium chloride salt. Modeling of the hygroscopic growth of these OS at 85% RH were also conducted. This new information has important implications about the atmospheric lifetime, light scattering properties, and the role of OS in cloud formation. Moreover, results of these studies can ultimately serve as a basis for the development and evaluation of thermodynamic models for these compounds in order to consider their impact on the atmosphere.