scholarly journals Modeling the surface tension of complex, reactive organic-inorganic mixtures

2013 ◽  
Vol 13 (1) ◽  
pp. 549-580 ◽  
Author(s):  
A. N. Schwier ◽  
G. A. Viglione ◽  
Z. Li ◽  
V. F. McNeill
Keyword(s):  
Surface Tension ◽  
Organic Compounds ◽  
Atmospheric Aerosols ◽  
Goodness Of Fit ◽  
Cloud Condensation Nuclei ◽  
Aqueous Mixtures ◽  
Surface Tension Data ◽  
Inorganic Systems ◽  
Experimental Surface ◽  
Using Data

Abstract. Atmospheric aerosols can contain thousands of organic compounds which impact aerosol surface tension, affecting aerosol properties such as cloud condensation nuclei (CCN) ability. We present new experimental data for the surface tension of complex, reactive organic-inorganic aqueous mixtures mimicking tropospheric aerosols. Each solution contained 2–6 organic compounds, including methylglyoxal, glyoxal, formaldehyde, acetaldehyde, oxalic acid, succinic acid, leucine, alanine, glycine, and serine, with and without ammonium sulfate. We test two surface tension models and find that most reactive, complex, aqueous organic mixtures which do not contain salt are well-described by a weighted Szyszkowski–Langmuir (S–L) model which was first presented by Henning et al. (2005). Two approaches for modeling the effects of salt were tested: (1) the Tuckermann approach (an extension of the Henning model with an additional explicit salt term), and (2) a new implicit method proposed here which employs experimental surface tension data obtained for each organic species in the presence of salt used with the Henning model. We recommend the use of method (2) for surface tension modeling because the Henning model (using data obtained from organic-inorganic systems) and Tuckermann approach provide similar modeling fits and goodness of fit (χ2) values, yet the Henning model is a simpler and more physical approach to modeling the effects of salt, requiring less empirically determined parameters.

scholarly journals Modeling the surface tension of complex, reactive organic–inorganic mixtures

2013 ◽  
Vol 13 (21) ◽  
pp. 10721-10732 ◽  
Author(s):  
A. N. Schwier ◽  
G. A. Viglione ◽  
Z. Li ◽  
V. Faye McNeill
Keyword(s):  
Surface Tension ◽  
Organic Compounds ◽  
Atmospheric Aerosols ◽  
Goodness Of Fit ◽  
Cloud Droplet ◽  
Aqueous Mixtures ◽  
Surface Tension Data ◽  
Inorganic Systems ◽  
Experimental Surface ◽  
Using Data

Abstract. Atmospheric aerosols can contain thousands of organic compounds which impact aerosol surface tension, affecting aerosol properties such as heterogeneous reactivity, ice nucleation, and cloud droplet formation. We present new experimental data for the surface tension of complex, reactive organic–inorganic aqueous mixtures mimicking tropospheric aerosols. Each solution contained 2–6 organic compounds, including methylglyoxal, glyoxal, formaldehyde, acetaldehyde, oxalic acid, succinic acid, leucine, alanine, glycine, and serine, with and without ammonium sulfate. We test two semi-empirical surface tension models and find that most reactive, complex, aqueous organic mixtures which do not contain salt are well described by a weighted Szyszkowski–Langmuir (S-L) model which was first presented by Henning et al. (2005). Two approaches for modeling the effects of salt were tested: (1) the Tuckermann approach (an extension of the Henning model with an additional explicit salt term), and (2) a new implicit method proposed here which employs experimental surface tension data obtained for each organic species in the presence of salt used with the Henning model. We recommend the use of method (2) for surface tension modeling of aerosol systems because the Henning model (using data obtained from organic–inorganic systems) and Tuckermann approach provide similar modeling results and goodness-of-fit (χ2) values, yet the Henning model is a simpler and more physical approach to modeling the effects of salt, requiring less empirically determined parameters.

scholarly journals Systematic Optimization of Water Models Using Liquid/Vapor Surface Tension Data

2019 ◽  
Author(s):  
Yudong Qiu ◽  
Paul S. Nerenberg ◽  
Teresa Head-Gordon ◽  
Lee-Ping Wang
Keyword(s):  
Surface Tension ◽  
Optimization Procedure ◽  
Kinetic Properties ◽  
Molecular Liquids ◽  
Surface Tension Data ◽  
Heat Of Vaporization ◽  
Experimental Surface ◽  
Temperature Of Maximum Density ◽  
Water Models ◽  
First Time

<div> <div> <div> <p>In this work we investigate whether experimental surface tension measurements, which are less sensitive to quantum and self-polarization corrections, are able to replace the usual reliance on the heat of vaporization as experimental reference data for fitting force field models of molecular liquids. To test this hypothesis we develop the fitting protocol necessary to utilize surface tension measurements in the ForceBalance optimization procedure in order to determine revised parameters for both three-point and four-point water models, TIP3P-ST and TIP4P-ST. We find that the incorporation of surface tension in the fit results in a rigid three-point model that reproduces the correct temperature of maximum density of water for the first time, but also leads to over-structuring of the liquid and less accurate transport properties. The rigid four-point TIP4P-ST model is highly accurate for a broad range of thermodynamic and kinetic properties, with similar performance compared to recently developed four- point water models. The results show surface tension to be a useful fitting property in general, especially when self-polarization corrections or nuclear quantum corrections are not readily available for correcting the heat of vaporization as is the case for other molecular liquids. </p> </div> </div> </div>

scholarly journals The Cloud Condensation Nuclei (CCN) properties of 2-methyltetrols and C3-C6 polyols from osmolality and surface tension measurements

2009 ◽  
Vol 9 (3) ◽  
pp. 973-980 ◽  
Author(s):  
S. Ekström ◽  
B. Nozière ◽  
H.-C. Hansson
Keyword(s):  
Surface Tension ◽  
Organic Acids ◽  
Organic Compounds ◽  
Organic Material ◽  
Cloud Condensation Nuclei ◽  
Global Scale ◽  
Significant Fraction ◽  
Cloud Formation ◽  
Condensation Nuclei ◽  
High Solubility

Abstract. A significant fraction of the organic material in aerosols is made of highly soluble compounds such as sugars (mono- and polysaccharides) and polyols such as the 2-methyltetrols, methylerythritol and methyltreitol. Because of their high solubility these compounds are considered as potentially efficient CCN material. For the 2-methyltetrols, this would have important implications for cloud formation at global scale because they are thought to be produced by the atmospheric oxidation of isoprene. To investigate this question, the complete Köhler curves for C3-C6 polyols and the 2-methyltetrols have been determined experimentally from osmolality and surface tension measurements. Contrary to what was expected, none of these compounds displayed a higher CCN efficiency than organic acids. Their Raoult terms show that this limited CCN efficiency is due to their absence of dissociation in water, this in spite of slight surface-tension effects for the 2-methyltetrols. Thus, compounds such as saccharides and polyols would not contribute more to cloud formation than other organic compounds studied so far. In particular, the presence of 2-methyltetrols in aerosols would not particularly enhance cloud formation in the atmosphere, in contrary to recently suggested.

scholarly journals New and extended parameterization of the thermodynamic model AIOMFAC: calculation of activity coefficients for organic-inorganic mixtures containing carboxyl, hydroxyl, carbonyl, ether, ester, alkenyl, alkyl, and aromatic functional groups

2011 ◽  
Vol 11 (17) ◽  
pp. 9155-9206 ◽  
Author(s):  
A. Zuend ◽  
C. Marcolli ◽  
A. M. Booth ◽  
D. M. Lienhard ◽  
V. Soonsin ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Functional Groups ◽  
Organic Compounds ◽  
Activity Coefficients ◽  
Atmospheric Aerosols ◽  
Atmospheric Chemistry ◽  
Inorganic Ions ◽  
Aqueous Mixtures ◽  
Organic Functional Groups ◽  
Ether Ester

Abstract. We present a new and considerably extended parameterization of the thermodynamic activity coefficient model AIOMFAC (Aerosol Inorganic-Organic Mixtures Functional groups Activity Coefficients) at room temperature. AIOMFAC combines a Pitzer-like electrolyte solution model with a UNIFAC-based group-contribution approach and explicitly accounts for interactions between organic functional groups and inorganic ions. Such interactions constitute the salt-effect, may cause liquid-liquid phase separation, and affect the gas-particle partitioning of aerosols. The previous AIOMFAC version was parameterized for alkyl and hydroxyl functional groups of alcohols and polyols. With the goal to describe a wide variety of organic compounds found in atmospheric aerosols, we extend here the parameterization of AIOMFAC to include the functional groups carboxyl, hydroxyl, ketone, aldehyde, ether, ester, alkenyl, alkyl, aromatic carbon-alcohol, and aromatic hydrocarbon. Thermodynamic equilibrium data of organic-inorganic systems from the literature are critically assessed and complemented with new measurements to establish a comprehensive database. The database is used to determine simultaneously the AIOMFAC parameters describing interactions of organic functional groups with the ions H+, Li+, Na+, K+, NH4+, Mg2+, Ca2+, Cl−, Br−, NO3−, HSO4−, and SO42−. Detailed descriptions of different types of thermodynamic data, such as vapor-liquid, solid-liquid, and liquid-liquid equilibria, and their use for the model parameterization are provided. Issues regarding deficiencies of the database, types and uncertainties of experimental data, and limitations of the model, are discussed. The challenging parameter optimization problem is solved with a novel combination of powerful global minimization algorithms. A number of exemplary calculations for systems containing atmospherically relevant aerosol components are shown. Amongst others, we discuss aqueous mixtures of ammonium sulfate with dicarboxylic acids and with levoglucosan. Overall, the new parameterization of AIOMFAC agrees well with a large number of experimental datasets. However, due to various reasons, for certain mixtures important deviations can occur. The new parameterization makes AIOMFAC a versatile thermodynamic tool. It enables the calculation of activity coefficients of thousands of different organic compounds in organic-inorganic mixtures of numerous components. Models based on AIOMFAC can be used to compute deliquescence relative humidities, liquid-liquid phase separations, and gas-particle partitioning of multicomponent mixtures of relevance for atmospheric chemistry or in other scientific fields.

scholarly journals New and extended parameterization of the thermodynamic model AIOMFAC: calculation of activity coefficients for organic-inorganic mixtures containing carboxyl, hydroxyl, carbonyl, ether, ester, alkenyl, alkyl, and aromatic functional groups

2011 ◽  
Vol 11 (5) ◽  
pp. 15297-15416 ◽  
Author(s):  
A. Zuend ◽  
C. Marcolli ◽  
A. M. Booth ◽  
D. M. Lienhard ◽  
V. Soonsin ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Functional Groups ◽  
Organic Compounds ◽  
Activity Coefficients ◽  
Atmospheric Aerosols ◽  
Atmospheric Chemistry ◽  
Inorganic Ions ◽  
Aqueous Mixtures ◽  
Organic Functional Groups ◽  
Ether Ester

Abstract. We present a new and considerably extended parameterization of the thermodynamic activity coefficient model AIOMFAC (Aerosol Inorganic-Organic Mixtures Functional groups Activity Coefficients) at room temperature. AIOMFAC combines a Pitzer-like electrolyte solution model with a UNIFAC-based group-contribution approach and explicitly accounts for interactions between organic functional groups and inorganic ions. Such interactions constitute the salt-effect, may cause liquid-liquid phase separation, and affect the gas-particle partitioning of aerosols. The previous AIOMFAC version was parameterized for alkyl and hydroxyl functional groups of alcohols and polyols. With the goal to describe a wide variety of organic compounds found in atmospheric aerosols, we extend here the parameterization of AIOMFAC to include the functional groups carboxyl, hydroxyl, ketone, aldehyde, ether, ester, alkenyl, alkyl, aromatic carbon-alcohol, and aromatic hydrocarbon. Thermodynamic equilibrium data of organic-inorganic systems from the literature are critically assessed and complemented with new measurements to establish a comprehensive database. The database is used to determine simultaneously the AIOMFAC parameters describing interactions of organic functional groups with the ions H+, Li+, Na+, K+, NH4+, Mg2+, Ca2+, Cl−, Br−, NO3−, HSO4−, and SO42−. Detailed descriptions of different types of thermodynamic data, such as vapor-liquid, solid-liquid, and liquid-liquid equilibria, and their use for the model parameterization are provided. Issues regarding deficiencies of the database, types and uncertainties of experimental data, and limitations of the model, are discussed. The challenging parameter optimization problem is solved with a novel combination of powerful global minimization algorithms. A number of exemplary calculations for systems containing atmospherically relevant aerosol components are shown. Amongst others, we discuss aqueous mixtures of ammonium sulfate with dicarboxylic acids and with levoglucosan. Overall, the new parameterization of AIOMFAC agrees well with a large number of experimental datasets. However, due to various reasons, for certain mixtures important deviations can occur. The new parameterization makes AIOMFAC a versatile thermodynamic tool. It enables the calculation of activity coefficients of thousands of different organic compounds in organic-inorganic mixtures of numerous components. Models based on AIOMFAC can be used to compute deliquescence relative humidities, liquid-liquid phase separations, and gas-particle partitioning of multicomponent mixtures of relevance for atmospheric chemistry or in other scientific fields.

Applicability of the Gibbs Adsorption Isotherm to the analysis of experimental surface-tension data for ionic and nonionic surfactants

2017 ◽  
Vol 247 ◽  
pp. 178-184 ◽  
Author(s):  
L. Martínez-Balbuena ◽  
Araceli Arteaga-Jiménez ◽  
Ernesto Hernández-Zapata ◽  
César Márquez-Beltrán
Keyword(s):  
Surface Tension ◽  
Adsorption Isotherm ◽  
Nonionic Surfactants ◽  
Surface Tension Data ◽  
Experimental Surface

scholarly journals Cloud condensation nuclei properties of model and atmospheric HULIS

2006 ◽  
Vol 6 (1) ◽  
pp. 1073-1120 ◽  
Author(s):  
E. Dinar ◽  
I. Taraniuk ◽  
E. R. Graber ◽  
S. Katsman ◽  
T. Moise ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Surface Tension ◽  
Fulvic Acid ◽  
Atmospheric Aerosols ◽  
Cloud Condensation Nuclei ◽  
Average Molecular Weight ◽  
Water Soluble ◽  
Number Average Molecular Weight ◽  
Secondary Sources ◽  
Multifunctional Compounds

Abstract. Humic like substances (HULIS) have been identified as a major fraction of the organic component of atmospheric aerosols. These large multifunctional compounds of both primary and secondary sources are surface active and water soluble. Hence, it is expected that they could affect activation of organic aerosols into cloud droplets. We have compared the activation of aerosols containing atmospheric HULIS extracted from fresh and slightly aged smoke particles and from daily pollution particles to activation of size fractionated fulvic acid from an aquatic source (Suwannee River fulvic acid), and correlated it to the estimated molecular weight and measured surface tension. A correlation was found between CCN-activation diameter of SRFA fractions and number average molecular weight of the fraction. The lower molecular weight fractions activated at lower critical diameters, which is explained by the greater number of solute species in the droplet with decreasing molecular weight. The three aerosol-extracted HULIS samples activated at lower diameters than any of the size-fractionated or bulk SRFA. By considering estimated number average molecular weight (MN), measured surface tension (ST) and activation diameters, the Köhler model was found to account for activation diameters, provided that accurate physico-chemical parameters are known.

scholarly journals The Cloud Condensation Nuclei (CCN) properties of 2-methyltetrols and C3–C6 polyols from osmolality and surface tension measurements

2008 ◽  
Vol 8 (5) ◽  
pp. 17237-17256 ◽  
Author(s):  
S. Ekström ◽  
B. Nozière ◽  
H.-C. Hansson
Keyword(s):  
Surface Tension ◽  
Organic Acids ◽  
Organic Compounds ◽  
Organic Material ◽  
Cloud Condensation Nuclei ◽  
Global Scale ◽  
Cloud Formation ◽  
Inorganic Salts ◽  
High Solubility ◽  
Critical Supersaturation

Abstract. A significant fraction of the organic material in aerosols is made of highly soluble compounds such as sugars (mono- and polysaccharides) and polyols, including the 2-methyltetrols, methylerythritol and methyltreitol. The high solubility of these compounds has brought the question of their potentially high CCN efficiency. For the 2-methyltetrols, this would have important implications for cloud formation at global scale because they are thought to be produced by the atmospheric oxidation of isoprene. To investigate this question, the complete Köhler curves for C3–C6 polyols and the 2-methyltetrols have been determined experimentally from osmolality and surface tension measurements. Contrary to what expected, none of these compounds displayed a critical supersaturation lower than those of inorganic salts or organic acids. Their Raoult terms show that this limited CCN efficiency is due to their absence of dissociation in water, this in spite of slight surface-tension effects for the 2-methyltetrols. Thus, compounds such as sugars and polyols would not contribute more to cloud formation in the atmosphere than any other organic compounds studied so far. In particular, the presence of 2-methyltetrols in aerosols would not particularly enhance cloud formation in the atmosphere, contrary to what has been suggested.

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