scholarly journals THE STRATEGY OF STUDYING THREE-LIQUID PHASE EQUILIBRIA IN THE CONCENTRATION SPACE OF QUATERNARY MIXTURES

2016 ◽  
Vol 11 (5) ◽  
pp. 65-69 ◽  
Author(s):  
A. Yu. Sebyakin ◽  
A. K. Frolkova
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Distillation Column ◽  
Mathematical Concept ◽  
Intersection Point ◽  
Topological Invariant ◽  
Fundamental Question ◽  
Liquid Phases ◽  
Concentration Space ◽  
Concentration Simplex

When separating multicomponent heterogeneous mixtures in units consisting of a distillation column and a decanter, a fundamental question is the location of phase separation regions with different numbers of liquid phases in the concentration simplex. A solution of this issue is based on data on the vapor-liquid and liquid-liquid equilibria of the mixture and its components, as well as on the general laws of the formation of the topological structure of phase separation areas. A strategy of studying the three-liquid phase equilibrium area in quaternary mixtures is proposed. The strategy is based on the formula of a topological invariant of the separation region and on the mathematical concept of centroid - the intersection point of three medians. The presence of threeliquid phase areas of separation of open and closed types is shown. They differ in the absence (presence) of region of degeneracy via the critical node.

scholarly journals Interactions between Phase-Separated Liquids and Membrane Surfaces

2021 ◽  
Vol 11 (3) ◽  
pp. 1288
Author(s):  
Samuel Botterbusch ◽  
Tobias Baumgart
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Critical Concentration ◽  
Protein Structures ◽  
Lipid Vesicles ◽  
Liquid Phase Separation ◽  
Membrane Surfaces ◽  
Liquid Phases ◽  
Spherical Droplets ◽  
Liquid Liquid Phase Separation

Liquid-liquid phase separation has recently emerged as an important fundamental organizational phenomenon in biological settings. Most studies of biological phase separation have focused on droplets that “condense” from solution above a critical concentration, forming so-called “membraneless organelles” suspended in solution. However, membranes are ubiquitous throughout cells, and many biomolecular condensates interact with membrane surfaces. Such membrane-associated phase-separated systems range from clusters of integral or peripheral membrane proteins in the plane of the membrane to free, spherical droplets wetting membrane surfaces to droplets containing small lipid vesicles. In this review, we consider phase-separated liquids that interact with membrane surfaces and we discuss the consequences of those interactions. The physical properties of distinct liquid phases in contact with bilayers can reshape the membrane, and liquid-liquid phase separation can construct membrane-associated protein structures, modulate their function, and organize collections of lipid vesicles dynamically. We summarize the common phenomena that arise in these systems of liquid phases and membranes.

scholarly journals Observations and implications of liquid–liquid phase separation at high relative humidities in secondary organic material produced by α-pinene ozonolysis without inorganic salts

2015 ◽  
Vol 15 (22) ◽  
pp. 33379-33405 ◽  
Author(s):  
L. Renbaum-Wolff ◽  
M. Song ◽  
C. Marcolli ◽  
Y. Zhang ◽  
P. F. Liu ◽  
...  
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Organic Material ◽  
Phase State ◽  
Liquid Phase Separation ◽  
Inorganic Salts ◽  
Laboratory Studies ◽  
Rich Phase ◽  
Liquid Phases ◽  
Liquid Liquid Phase Separation

Abstract. Particles consisting of secondary organic material (SOM) are abundant in the atmosphere. To predict the role of these particles in climate, visibility, and atmospheric chemistry, information on particle phase state (i.e. single liquid, two liquids, solid and so forth) is needed. This paper focuses on the phase state of SOM particles free of inorganic salts produced by the ozonolysis of α-pinene. Phase transitions were investigated both in the laboratory and with a thermodynamic model over the range of < 0.5 % to 100 % relative humidity (RH) at 290 K. In the laboratory studies, a single phase was observed from 0 to 95 % RH while two liquid phases were observed above 95 % RH. For increasing RH, the mechanism of liquid–liquid phase separation (LLPS) was spinodal decomposition. The RH range at which two liquid phases were observed did not depend on the direction of RH change. In the modelling studies at low RH values, the SOM took up hardly any water and was a single organic-rich phase. At high RH values, the SOM underwent LLPS to form an organic-rich phase and an aqueous phase, consistent with the laboratory studies. The presence of LLPS at high RH-values has consequences for the cloud condensation nuclei (CCN) activity of SOM particles. In the simulated Köhler curves for SOM particles, two local maxima are observed. Depending on the composition of the SOM, the first or second maximum can determine the critical supersaturation for activation. The presence of LLPS at high RH-values can explain inconsistencies between measured CCN properties of SOM particles and hygroscopic growth measured below water saturation.

scholarly journals Effects of liquid–liquid phase separation and relative humidity on the heterogeneous OH oxidation of inorganic–organic aerosols: insights from methylglutaric acid and ammonium sulfate particles

2021 ◽  
Vol 21 (3) ◽  
pp. 2053-2066
Author(s):  
Hoi Ki Lam ◽  
Rongshuang Xu ◽  
Jack Choczynski ◽  
James F. Davies ◽  
Dongwan Ham ◽  
...  
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Gas Phase ◽  
Organic Compounds ◽  
Organic Molecules ◽  
Droplet Surface ◽  
Core Shell ◽  
Oh Radicals ◽  
Liquid Phases ◽  
Heterogeneous Reactivity

Abstract. Organic compounds residing near the surface of atmospheric aerosol particles are exposed to chemical reactions initiated by gas-phase oxidants, such as hydroxyl (OH) radicals. Aqueous droplets composed of inorganic salts and organic compounds can undergo phase separation into two liquid phases, depending on aerosol composition and relative humidity (RH). Such phase behavior can govern the surface characteristics and morphology of the aerosols, which in turn affect the heterogeneous reactivity of organic compounds toward gas-phase oxidants. In this work, we used an aerosol flow tube reactor coupled with an atmospheric pressure ionization source (direct analysis in real time) and a high-resolution mass spectrometer to investigate how phase separation in model aqueous droplets containing an inorganic salt (ammonium sulfate, AS) and an organic acid (3-methylglutaric acid, 3-MGA) with an organic-to-inorganic dry mass ratio (OIR) of 1 alters the heterogeneous OH reactivity. At high RH, 3-MGA/AS aerosols were aqueous droplets with a single liquid phase. When the RH decreased, aqueous 3-MGA/AS droplets underwent phase separation at ∼75 % RH. Once the droplets were phase-separated, they exhibited either a core–shell, partially engulfed or a transition from core–shell to partially engulfed structure, with an organic-rich outer phase and an inorganic-rich inner phase. The kinetics, quantified by an effective heterogenous OH rate constant, was found to increase gradually from 1.01±0.02×10-12 to 1.73±0.02×10-12 cm3 molec.−1 s−1 when the RH decreased from 88 % to 55 %. The heterogeneous reactivity of phase-separated droplets is slightly higher than that of aqueous droplets with a single liquid phase. This could be explained by the finding that when the RH decreases, higher concentrations of organic molecules (i.e., 3-MGA) are present at or near the droplet surface, which are more readily exposed to OH oxidation, as demonstrated by phase separation measurements and model simulations. This could increase the reactive collision probability between 3-MGA molecules and OH radicals dissolved near the droplet surface and secondary chain reactions. Even for phase-separated droplets with a fully established core–shell structure, the diffusion rate of organic molecules across the organic-rich outer shell is predicted to be fast in this system. Thus, the overall rate of reactions is likely governed by the surface concentration of 3-MGA rather than a diffusion limitation. Overall, understanding the aerosol phase state (single liquid phase versus two separate liquid phases) is essential to better probe the heterogenous reactivity under different aerosol chemical composition and environmental conditions (e.g., RH).

scholarly journals Observations and implications of liquid–liquid phase separation at high relative humidities in secondary organic material produced by <i>α</i>-pinene ozonolysis without inorganic salts

2016 ◽  
Vol 16 (12) ◽  
pp. 7969-7979 ◽  
Author(s):  
Lindsay Renbaum-Wolff ◽  
Mijung Song ◽  
Claudia Marcolli ◽  
Yue Zhang ◽  
Pengfei F. Liu ◽  
...  
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Organic Material ◽  
Phase State ◽  
Water Saturation ◽  
Inorganic Salts ◽  
Laboratory Studies ◽  
Rich Phase ◽  
Liquid Phases ◽  
Liquid Liquid Phase Separation

Abstract. Particles consisting of secondary organic material (SOM) are abundant in the atmosphere. To predict the role of these particles in climate, visibility and atmospheric chemistry, information on particle phase state (i.e., single liquid, two liquids and solid) is needed. This paper focuses on the phase state of SOM particles free of inorganic salts produced by the ozonolysis of α-pinene. Phase transitions were investigated in the laboratory using optical microscopy and theoretically using a thermodynamic model at 290 K and for relative humidities ranging from  <  0.5 to 100 %. In the laboratory studies, a single phase was observed from 0 to 95 % relative humidity (RH) while two liquid phases were observed above 95 % RH. For increasing RH, the mechanism of liquid–liquid phase separation (LLPS) was spinodal decomposition. The RH range over which two liquid phases were observed did not depend on the direction of RH change. In the modeling studies, the SOM took up very little water and was a single organic-rich phase at low RH values. At high RH, the SOM underwent LLPS to form an organic-rich phase and a water-rich phase, consistent with the laboratory studies. The presence of LLPS at high RH values can have consequences for the cloud condensation nuclei (CCN) activity of SOM particles. In the simulated Köhler curves for SOM particles, two local maxima were observed. Depending on the composition of the SOM, the first or second maximum can determine the critical supersaturation for activation. Recently researchers have observed inconsistencies between measured CCN properties of SOM particles and hygroscopic growth measured below water saturation (i.e., hygroscopic parameters measured below water saturation were inconsistent with hygroscopic parameters measured above water saturation). The work presented here illustrates that such inconsistencies are expected for systems with LLPS when the water uptake at subsaturated conditions represents the hygroscopicity of an organic-rich phase while the barrier for CCN activation can be determined by the second maximum in the Köhler curve when the particles are water rich.

scholarly journals An in silico LLPS perturbation approach in the design of a novel SARS-CoV-2 spike receptor-binding domain inhibitor

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Olanrewaju Ayodeji Durojaye ◽  
Divine Mensah Sedzro ◽  
Talifhani Mushiana ◽  
Henrietta Onyinye Uzoeto ◽  
Samuel Cosmas ◽  
...  
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Liquid Phase Separation ◽  
Perturbation Approach ◽  
P Bodies ◽  
Important Principle ◽  
Liquid Phases ◽  
Membrane Envelope ◽  
Liquid Liquid Phase Separation ◽  
Chromatin Rearrangement

AbstractThe reversible process where a homogenous fluid de-mixes into two distinctively separate liquid phases is referred to as LLPS (Liquid-liquid phase separation). The resulting liquid is made up of one dilute phase and one condensed phase. An increasing number of studies have shown that the liquid-liquid phase separation is an important principle that underlies intracellular organization in biological systems, forming liquid condensates without a membrane envelope, otherwise known as MLOs (membraneless organelles). Such organelles include the P bodies, nucleolus and stress granules. Moreover, the regulation of many other biological processes such as signal transduction, chromatin rearrangement and RNA metabolism have been linked to the liquid-liquid phase separation.

scholarly journals Liquid–liquid phase separation and morphologies in organic particles consisting of <i>α</i>-pinene and <i>β</i>-caryophyllene ozonolysis products and mixtures with commercially available organic compounds

2020 ◽  
Vol 20 (19) ◽  
pp. 11263-11273
Author(s):  
Young-Chul Song ◽  
Ariana G. Bé ◽  
Scot T. Martin ◽  
Franz M. Geiger ◽  
Allan K. Bertram ◽  
...  
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Aerosol Particles ◽  
Organic Aerosol ◽  
Nucleation And Growth ◽  
Liquid Phases ◽  
Two Component ◽  
Organic Particles ◽  
Nucleation And Growth Mechanism ◽  
Liquid Liquid Phase Separation

Abstract. Liquid–liquid phase separation (LLPS) in organic aerosol particles can impact several properties of atmospheric particulate matter, such as cloud condensation nuclei (CCN) properties, optical properties, and gas-to-particle partitioning. Yet, our understanding of LLPS in organic aerosols is far from complete. Here, we report on the LLPS of one-component and two-component organic particles consisting of α-pinene- and β-caryophyllene-derived ozonolysis products and commercially available organic compounds of relevance to atmospheric organic particles. In the experiments involving single-component organic particles, LLPS was observed in 8 out of 11 particle types studied. LLPS almost always occurred when the oxygen-to-carbon elemental ratio (O:C) was ≤0.44 but did not occur when O:C was >0.44. The phase separation occurred by spinodal decomposition as well as the nucleation and growth mechanism, and when LLPS occurred, two liquid phases coexisted up to ∼100 % relative humidity (RH). In the experiments involving two-component organic particles, LLPS was observed in 23 out of 25 particles types studied. LLPS almost always occurred when the average was O:C ≤0.67 but never occurred when the average O:C was >0.67. The phase separation occurred by spinodal decomposition as well as the nucleation and growth mechanism. When LLPS occurred, two liquid phases coexisted up to ∼100 % RH. These results provide further evidence that LLPS is likely a frequent occurrence in organic aerosol particles in the troposphere, even in the absence of inorganic salts.

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.

scholarly journals Effects of Liquid–Liquid Phase Separation and Relative Humidity on the Heterogeneous OH Oxidation of Inorganic–Organic Aerosols: Insights from Methylglutaric Acid/Ammonium Sulfate Particles

2020 ◽  
Author(s):  
Hoi Ki Lam ◽  
Rongshuang Xu ◽  
Jack Choczynski ◽  
James F. Davies ◽  
Dongwan Ham ◽  
...  
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Gas Phase ◽  
Organic Compounds ◽  
Organic Molecules ◽  
Droplet Surface ◽  
Core Shell ◽  
Oh Radicals ◽  
Liquid Phases ◽  
Heterogeneous Reactivity

Abstract. Organic compounds residing near the surface of atmospheric aerosol particles are exposed to chemical reactions initiated by gas-phase oxidants, such as hydroxyl (OH) radicals. Aqueous droplets composed of inorganic salts and organic compounds can undergo phase separation into two liquid phases, depending on aerosol composition and relative humidity (RH). Such phase behavior can govern the surface characteristics and morphology of the aerosols, which in turn affect the heterogeneous reactivity of organic compounds toward gas-phase oxidants. In this work, we used an aerosol flow tube reactor coupled with an atmospheric pressure ionization source (Direct Analysis in Real Time) and a high-resolution mass spectrometer to investigate how phase separation in model aqueous droplets containing an inorganic salt (ammonium sulfate, AS) and an organic acid (3-methyglutaric acid, 3-MGA) with an organic-to-inorganic dry mass ratio (OIR) of 1 alters the heterogeneous OH reactivity. At high RH, 3-MGA/AS aerosols were aqueous droplets with a single liquid phase. When the RH decreased, aqueous 3-MGA/AS droplets underwent phase separation at ~75 % RH. Once the droplets were phase-separated, they exhibited either a core–shell, partially engulfed, or a transition from core–shell to partially engulfed structure, with an organic-rich outer phase and an inorganic-rich inner phase. The kinetics, quantified by an effective heterogenous OH rate constant, was found to increase gradually from 1.01 ± 0.02 × 10e−12 to 1.73 ± 0.02 × 10e−12 cm3 molecule−1 s−1 when the RH decreased from 88 % to 55 %. The heterogeneous reactivity of phase-separated droplets is slightly higher than that of aqueous droplets with a single liquid phase. This could be explained by the finding that when the RH decreases, higher concentrations of organic molecules (i.e. 3-MGA) are present at or near the droplet surface, which are more readily exposed to OH oxidation, as demonstrated by phase separation measurements and model simulations. This could increase the reactive collision probability between 3-MGA molecules and OH radicals dissolved near the droplet surface and secondary chain reactions. Even for phase-separated droplets with a fully established core–shell structure, the diffusion rate of organic molecules across the organic-rich outer shell is predicted to be fast in this system. Thus, the overall rate of reactions is likely governed by the surface concentration of 3-MGA rather than a diffusion limitation. Overall, understanding the aerosol phase state (single liquid phase versus two separate liquid phases) is essential to better probe the heterogenous reactivity under different aerosol chemical composition and environmental conditions (e.g. RH).

scholarly journals Liquid–liquid phase separation in organic particles consisting of α-pinene and β-caryophyllene ozonolysis products and mixtures with commercially-available organic compounds

2020 ◽  
Author(s):  
Young-Chul Song ◽  
Ariana G. Bé ◽  
Scot T. Martin ◽  
Franz M. Geiger ◽  
Allan K. Bertram ◽  
...  
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Organic Compounds ◽  
Spinodal Decomposition ◽  
Aerosol Particles ◽  
Organic Aerosol ◽  
Liquid Phases ◽  
Two Component ◽  
Organic Particles ◽  
Liquid Liquid Phase Separation

Abstract. Liquid–liquid phase separation (LLPS) in organic aerosol particles can impact several properties of atmospheric particulate matter, such as cloud condensation nuclei (CCN) properties, optical properties, and gas-to-particle partitioning. Yet, our understanding of LLPS in organic aerosols is far from complete. Here, we report on LLPS of one-component and two-component organic particles consisting of α-pinene- and β-caryophyllene-derived ozonolysis products and commercially-available organic compounds of relevance to atmospheric organic particles. In the experiments involving single-component organic particles, LLPS was observed in 8 out of 11 particle types studied. LLPS almost always occurred when the oxygen-to-carbon elemental ratio (O : C) was ≤ 0.44, but did not occur when O : C was > 0.44. The phase separation occurred by spinodal decomposition, and when LLPS occurred, two liquid phases co-existed up to ~ 100 % relative humidity (RH). In the experiments involving two-component organic particles, LLPS was observed in 23 out of 25 particles types studied. LLPS almost always occurred when the average was O : C ≤ 0.67, but never occurred when the average O : C was > 0.67. The phase separation occurred by spinodal decomposition or growth of a second phase at the surface of the particles. When LLPS occurred, two liquid phases co-existed up to ~ 100 %. These results provide further evidence that LLPS is likely a frequent occurrence in organic aerosol particles in the troposphere, even in the absence of inorganic salts.

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