Liquid−Liquid Phase Separation in Mixed Organic/Inorganic Aerosol Particles

2009 ◽  
Vol 113 (41) ◽  
pp. 10966-10978 ◽  
Author(s):  
V. Gabriela Ciobanu ◽  
Claudia Marcolli ◽  
Ulrich K. Krieger ◽  
Uwe Weers ◽  
Thomas Peter
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Aerosol Particles ◽  
Liquid Phase Separation ◽  
Inorganic Aerosol ◽  
Liquid Liquid Phase Separation

scholarly journals Computation of liquid-liquid equilibria and phase stabilities: implications for RH-dependent gas/particle partitioning of organic-inorganic aerosols

2010 ◽  
Vol 10 (16) ◽  
pp. 7795-7820 ◽  
Author(s):  
A. Zuend ◽  
C. Marcolli ◽  
T. Peter ◽  
J. H. Seinfeld
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Water Solubility ◽  
Inorganic Compounds ◽  
Liquid Phase Separation ◽  
Miscibility Gap ◽  
Inorganic Aerosols ◽  
Particulate Mass ◽  
Inorganic Aerosol ◽  
Liquid Liquid Phase Separation

Abstract. Semivolatile organic and inorganic aerosol species partition between the gas and aerosol particle phases to maintain thermodynamic equilibrium. Liquid-liquid phase separation into an organic-rich and an aqueous electrolyte phase can occur in the aerosol as a result of the salting-out effect. Such liquid-liquid equilibria (LLE) affect the gas/particle partitioning of the different semivolatile compounds and might significantly alter both particle mass and composition as compared to a one-phase particle. We present a new liquid-liquid equilibrium and gas/particle partitioning model, using as a basis the group-contribution model AIOMFAC (Zuend et al., 2008). This model allows the reliable computation of the liquid-liquid coexistence curve (binodal), corresponding tie-lines, the limit of stability/metastability (spinodal), and further thermodynamic properties of multicomponent systems. Calculations for ternary and multicomponent alcohol/polyol-water-salt mixtures suggest that LLE are a prevalent feature of organic-inorganic aerosol systems. A six-component polyol-water-ammonium sulphate system is used to simulate effects of relative humidity (RH) and the presence of liquid-liquid phase separation on the gas/particle partitioning. RH, salt concentration, and hydrophilicity (water-solubility) are identified as key features in defining the region of a miscibility gap and govern the extent to which compound partitioning is affected by changes in RH. The model predicts that liquid-liquid phase separation can lead to either an increase or decrease in total particulate mass, depending on the overall composition of a system and the particle water content, which is related to the hydrophilicity of the different organic and inorganic compounds. Neglecting non-ideality and liquid-liquid phase separations by assuming an ideal mixture leads to an overestimation of the total particulate mass by up to 30% for the composition and RH range considered in the six-component system simulation. For simplified partitioning parametrizations, we suggest a modified definition of the effective saturation concentration, Cj*, by including water and other inorganics in the absorbing phase. Such a Cj* definition reduces the RH-dependency of the gas/particle partitioning of semivolatile organics in organic-inorganic aerosols by an order of magnitude as compared to the currently accepted definition, which considers the organic species only.

scholarly journals Liquid–Liquid Phase Separation in Aerosol Particles: Imaging at the Nanometer Scale

2015 ◽  
Vol 49 (8) ◽  
pp. 4995-5002 ◽  
Author(s):  
Rachel E. O’Brien ◽  
Bingbing Wang ◽  
Stephen T. Kelly ◽  
Nils Lundt ◽  
Yuan You ◽  
...  
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Aerosol Particles ◽  
Liquid Phase Separation ◽  
Nanometer Scale ◽  
Liquid Liquid Phase Separation

scholarly journals Liquid-liquid phase separation in secondary organic aerosol particles produced from α-pinene ozonolysis and α-pinene photo-oxidation with/without ammonia

2019 ◽  
Author(s):  
Suhan Ham ◽  
Zaeem Bin Babar ◽  
Jaebong Lee ◽  
Hojin Lim ◽  
Mijung Song
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Secondary Organic Aerosol ◽  
Cloud Condensation Nuclei ◽  
Aerosol Particles ◽  
Organic Aerosol ◽  
Liquid Phase Separation ◽  
Photo Oxidation ◽  
Different Types ◽  
Liquid Liquid Phase Separation

Abstract. Recently, liquid–liquid phase separation (LLPS) of secondary organic aerosol (SOA) particles free of inorganic salts has been intensively studied because of their importance on cloud condensation nuclei (CCN) properties. Herein, we investigated LLPS in four different types of SOA particles generated from α-pinene ozonolysis and α-pinene photo-oxidation in the absence and presence of NH3. LLPS was observed in SOA particles produced from α-pinene ozonolysis at ~ 95.8 % relative humidity (RH) and α-pinene ozonolysis with NH3 at ~ 95.4 % RH. However, LLPS was not observed in SOA particles produced from α-pinene photo-oxidation and α-pinene photo-oxidation with NH3. With datasets of average oxygen to carbon elemental ratio (O : C) for different types of SOA particles of this study and previous studies, LLPS occurred when the O : C ratio was less than ~ 0.44 and LLPS did not occur when the O : C ratio was greater than ~ 0.40. When LLPS was observed, the two liquid phases were present up to ~ 100 % RH. This result can help to predict more accurate results of CCN properties of organic aerosol particles.

scholarly journals Computation of liquid-liquid equilibria and phase stabilities: implications for RH-dependent gas/particle partitioning of organic-inorganic aerosols

2010 ◽  
Vol 10 (5) ◽  
pp. 12497-12561 ◽  
Author(s):  
A. Zuend ◽  
C. Marcolli ◽  
T. Peter ◽  
J. H. Seinfeld
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Water Solubility ◽  
Inorganic Compounds ◽  
Liquid Phase Separation ◽  
Miscibility Gap ◽  
Inorganic Aerosols ◽  
Particulate Mass ◽  
Inorganic Aerosol ◽  
Liquid Liquid Phase Separation

Abstract. Semivolatile organic and inorganic aerosol species partition between the gas and aerosol particle phases to maintain thermodynamic equilibrium. Liquid-liquid phase separation into an organic-rich and an aqueous electrolyte phase can occur in the aerosol as a result of the salting-out effect. Such liquid-liquid equilibria (LLE) affect the gas/particle partitioning of the different semivolatile compounds and might significantly alter both particle mass and composition as compared to a one-phase particle. We present a new liquid-liquid equilibrium and gas/particle partitioning model, using as a basis the group-contribution model AIOMFAC (Zuend et al., 2008). This model allows the reliable computation of the liquid-liquid coexistence curve (binodal), corresponding tie-lines, the limit of stability/metastability (spinodal), and further thermodynamic properties of the phase diagram. Calculations for ternary and multicomponent alcohol/polyol-water-salt mixtures suggest that LLE are a prevalent feature of organic-inorganic aerosol systems. A six-component polyol-water-ammonium sulphate system is used to simulate effects of relative humidity (RH) and the presence of liquid-liquid phase separation on the gas/particle partitioning. RH, salt concentration, and hydrophilicity (water-solubility) are identified as key features in defining the region of a miscibility gap and govern the extent to which compound partitioning is affected by changes in RH. The model predicts that liquid-liquid phase separation can lead to either an increase or decrease in total particulate mass, depending on the overall composition of a system and the particle water content, which is related to the hydrophilicity of the different organic and inorganic compounds. Neglecting non-ideality and liquid-liquid phase separations by assuming an ideal mixture leads to an overestimation of the total particulate mass by up to 30% for the composition and RH range considered in the six-component system simulation. For simplified partitioning parametrizations, we suggest a modified definition of the effective saturation concentration, C*j, by including water and other inorganics in the absorbing phase. Such a C*j definition reduces the RH-dependency of the gas/particle partitioning of semivolatile organics in organic-inorganic aerosols by an order of magnitude as compared to the currently accepted definition, which considers the organic species only.

scholarly journals Liquid–liquid phase separation in secondary organic aerosol particles produced from <i>α</i>-pinene ozonolysis and <i>α</i>-pinene photooxidation with/without ammonia

2019 ◽  
Vol 19 (14) ◽  
pp. 9321-9331 ◽  
Author(s):  
Suhan Ham ◽  
Zaeem Bin Babar ◽  
Jae Bong Lee ◽  
Ho-Jin Lim ◽  
Mijung Song
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Secondary Organic Aerosol ◽  
Cloud Condensation Nuclei ◽  
Aerosol Particles ◽  
Organic Aerosol ◽  
Liquid Phase Separation ◽  
Liquid Phases ◽  
Different Types ◽  
Liquid Liquid Phase Separation

Abstract. Recently, liquid–liquid phase separation (LLPS) of secondary organic aerosol (SOA) particles free of inorganic salts has been intensively studied due to the importance of cloud condensation nuclei (CCN) properties. In this study, we investigated LLPS in four different types of SOA particles generated from α-pinene ozonolysis and α-pinene photooxidation in the absence and presence of ammonia (NH3). LLPS was observed in SOA particles produced from α-pinene ozonolysis at ∼95.8 % relative humidity (RH) and α-pinene ozonolysis with NH3 at ∼95.4 % RH. However, LLPS was not observed in SOA particles produced from α-pinene photooxidation and α-pinene photooxidation with NH3. Based on datasets of the average oxygen to carbon elemental ratio (O:C) for different types of SOA particles from this study and from previous studies, there appears to be a relationship between the occurrence of LLPS and the O:C of the SOA particles. When LLPS was observed, the two liquid phases were present up to ∼100 % RH. This result can help more accurately predict the CCN properties of organic aerosol particles.

Phase separation in organic aerosol

2017 ◽  
Vol 46 (24) ◽  
pp. 7694-7705 ◽  
Author(s):  
Miriam Arak Freedman
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Organic Compounds ◽  
Aerosol Particles ◽  
Organic Aerosol ◽  
Liquid Phase Separation ◽  
Climate Effects ◽  
Liquid Liquid Phase Separation

Liquid–liquid phase separation is prevalent in aerosol particles composed of organic compounds and salts and may impact aerosol climate effects.

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