Premium
Liquid‐liquid phase separation in aerosol particles: Dependence on O:C, organic functionalities, and compositional complexity
Author(s) -
Song M.,
Marcolli C.,
Krieger U. K.,
Zuend A.,
Peter T.
Publication year - 2012
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2012gl052807
Subject(s) - aerosol , relative humidity , total organic carbon , ammonium sulfate , carbon number , range (aeronautics) , troposphere , chemistry , phase (matter) , analytical chemistry (journal) , environmental chemistry , materials science , chromatography , thermodynamics , atmospheric sciences , organic chemistry , physics , alkyl , composite material
Atmospheric aerosol particles may undergo liquid‐liquid phase separation (LLPS) when exposed to varying relative humidity. In this study we investigated the occurrence of LLPS for mixtures consisting of up to ten organic compounds, ammonium sulfate, and water in relationship with the organic oxygen‐to‐carbon (O:C) ratio. LLPS always occurred for O:C < 0.56, never occurred for O:C > 0.80, and depended on the specific types and compositions of organic functional groups in the regime 0.56 < O:C < 0.80. In the intermediate regime, mixtures with a high share of aromatic compounds shifted the limit of occurrence of LLPS to lower O:C ratios. The number of mixture components and the spread of the O:C range did not notably influence the conditions for LLPS to occur. Since in ambient aerosols O:C range typically between 0.2 and 1.0, LLPS is expected to be a common feature of tropospheric aerosols.