Thermophysical and Thermochemical PropertiesNovember 25, 2025

Surface Tension and Surface Thermodynamics of Aqueous Inorganic Salt Solutions in the Atmospherically Relevant Temperature Range
Click to copy article linkArticle link copied!

Alexandra Giermann
Alexandra Giermann
Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstraße 2, 04103 Leipzig, Germany
More by Alexandra Giermann
Manuela Reichelt*
Manuela Reichelt
Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstraße 2, 04103 Leipzig, Germany
*Email: [email protected]
More by Manuela Reichelt
https://orcid.org/0000-0002-8365-1671

Open PDF Supporting Information (1)

Journal of Chemical & Engineering Data

Cite this: J. Chem. Eng. Data 2025, 70, 12, 4901–4914

Click to copy citationCitation copied!

https://doi.org/10.1021/acs.jced.5c00470

Published November 25, 2025

CC-BY 4.0 .

Abstract

Click to copy section linkSection link copied!

The surface tension γ of aqueous solutions of NaCl, NaBr, NaI, LiCl, KCl, MgCl₂, and Na₂SO₄ (0.1 mol·kg^–1 to 5 mol·kg^–1 in maximum) was investigated within the atmospheric relevant temperature range of 263.15 to 293.15 K. The measured densities ρ of the aqueous inorganic salt solutions between 278.15 and 293.15 K are also reported. From experimental data the excess surface tension Δγ, the concentration (as molality m) and temperature derivatives, (dγ/dm)_T, p and (dγ/dT)_p, m as well as thermodynamic quantities of surface formation such as surface excess entropy $Δ s^{σ}$ , surface excess Helmholtz energy $Δ a^{σ}$ , surface excess energy $Δ u^{σ}$ , and surface excess enthalpy $Δ h^{σ}$ were estimated. The surface excess entropy decreases slightly with increasing molality of the inorganic salt, which shows a weak order dependence of the water molecules on the salt concentration. The surface tension data and thermodynamic quantities complement existing data sets especially at temperatures below 283.15 K.

This publication is licensed under

CC-BY 4.0 .

License Summary*
You are free to share(copy and redistribute) this article in any medium or format and to adapt(remix, transform, and build upon) the material for any purpose, even commercially within the parameters below:
- Creative Commons (CC): This is a Creative Commons license.
- Attribution (BY): Credit must be given to the creator.
View full license
*Disclaimer
This summary highlights only some of the key features and terms of the actual license. It is not a license and has no legal value. Carefully review the actual license before using these materials.
License Summary*
You are free to share(copy and redistribute) this article in any medium or format and to adapt(remix, transform, and build upon) the material for any purpose, even commercially within the parameters below:
- Creative Commons (CC): This is a Creative Commons license.
- Attribution (BY): Credit must be given to the creator.
View full license
*Disclaimer
This summary highlights only some of the key features and terms of the actual license. It is not a license and has no legal value. Carefully review the actual license before using these materials.

Subjects

1. Introduction

Click to copy section linkSection link copied!

In a huge number of field campaigns and long-term observations, the composition of atmospheric aerosol particles was investigated (e.g. (1−12)). Depending on the altitude, latitude, season, and region (marine, urban, rural, and so on) at which aerosol particles were collected, inorganic as well as a range of organic compounds were identified. Especially in marine aerosol, larger amounts of inorganic components were found that appear as dissolved cations and anions and are mainly Na⁺, Mg²⁺, NH₄⁺, Cl^–, Br^–, NO₃^–, HSO₄^–, SO₄^2–, among others. (13,14) The organic matter is substantially more complex. (15) So dimethyl sulfide from phytoplankton, as well as different longer chain fatty acids, occur more frequently in marine aerosol or so-called “human-like” species in urban regions or from biomass burning. (16,17) Longer chain organic molecules are typical surfactants that exhibit a hydrophobic and a hydrophilic moiety. Therefore, they tend to adsorb at surfaces and lower the surface tension of the liquid surface. At the so-called critical micelle concentration (CMC), they form micelle aggregates. In the presence of inorganic salts adsorption of surfactants at the liquid surface becomes more intense, and the CMC is shifted to a lower concentration. (18−20) These effects also occur in cloud droplets in the atmosphere, where they can affect the water uptake or adsorption of substances from the gas phase and thus chemical reactions at the droplet surface as well as formation and growth of cloud droplets in a significant manner, and as a consequence, also precipitation and radiative climate forcing are influenced. (21−23) Since inorganic salts play an important role in atmospheric chemistry, their hydration at the air/water interface plays a crucial role in understanding the surface speciation and the reactivity in atmospheric aerosol. Jungwirth and Tobias received surprising results in modeling the air/water interface of aqueous sodium halide solutions, providing a completely new perspective on the distribution of anions and cations in the interfacial region. (24) Larger, polarizable anions showed an enrichment at the air–water interface that was in contrast to the previously regarded depletion of ions in the interfacial region. Depletion or enrichment of substances influences the physicochemical properties of interfaces. An important quantity in the characterization and modeling of a liquid surface is its surface tension as well as its change with the solute concentration (surface tension gradient) and other thermodynamic quantities. (25) Therefore, these parameters are also important in atmospheric cloud formation models. (19,25)

Several studies of thermodynamics of solute adsorption at surfaces and interfaces of liquids, including general formulations, were published by Motomura et al. (26−29) Matubayasi et al. applied these formulations in their own studies concerning the thermodynamic surface excess quantities of aqueous electrolyte solutions. (30−32) The following equations for calculating different thermodynamic quantities are based on these works. All thermodynamic quantities expressed here by lower case letters with the superscript σ represent excess quantities per unit area with reference to the pure solvent as recommended by the International Union of Pure and Applied Chemistry (IUPAC). (33)

Strong electrolytes dissociate completely into ν₊ cations and ν_– anions when they are dissolved in water. The change in surface tension dγ of a salt solution depends on temperature T, pressure p as well as molality m and can be described by the following equation:

dγ = - Δ s^{σ} d T + v^{σ} d p - \frac{(ν_{+} + ν_{-}) \cdot R \cdot T \cdot Γ^{σ}}{m} {(1 + \frac{\partial \ln f_{\pm}}{\partial \ln m})}_{T, p} d m

(1)

with the surface excess entropy Δs^σ, the volume of surface formation v^σ, the stoichiometric coefficient ν, the universal gas constant R, the total surface excess concentration Γ^σ, and the mean activity coefficient f_± of the inorganic salt.

From temperature-dependent surface tension measurements at p, m = const surface excess entropy can be calculated by means of:

Δ s^{σ} = - {(\frac{∂γ}{\partial T})}_{p, m}

(2)

The thermodynamic quantities surface excess Helmholtz energy Δa^σ, surface excess energy Δu^σ, surface excess enthalpy Δh^σ and surface excess Gibbs energy Δg^σ are related as follows:

Δ a^{σ} = Δ u^{σ} - T \cdot Δ s^{σ}

(3)

Δ u^{σ} = Δ h^{σ} + γ = T \cdot Δ s^{σ} - p \cdot Δ v^{σ} + γ

(4)

Δ g^{σ} = Δ h^{σ} - T \cdot Δ s^{σ} = Δ a^{σ} - γ

(5)

In the case of an ideal surface, no volume work is expected. For a real surface, the contribution from volume work was estimated by Motomura et al., who obtained a value of pΔv^σ = −0.0831 mJ·m^–2. (29) Compared to those values of γ and T · Δs^σ, it is very small and can be neglected. This simplifies eqs 3 to 5 as follows:

Δ h^{σ} = T \cdot Δ s^{σ}

(6)

Δ a^{σ} = γ

(7)

and leads also to Δg^σ = 0, which is to be expected for the equilibrium state of the solution surface.

Finally, the values of the surface excess energy and entropy can be determined graphically by linear regression of the γ-T graphs with slope Δs^σ and y-intercept Δu^σ:

γ = Δ u^{σ} - T \cdot Δ s^{σ}

(8)

The excess surface tension

Δ γ

characterizes the ability of the solute to reduce or raise the surface tension of the solvent

γ_{0}

Δ γ = γ - γ_{0}

(9)

This work is focused on surface tension data of several aqueous inorganic salt solutions and thermodynamic quantities of their surface in an atmospherically relevant temperature range of 263.15–293.15 K. Most published data refer to measurements at 288.15 K or higher. (31,32,34−40) Only few data sets received at lower temperature are available such as in Shah et al. (41) for several aqueous inorganic salt solutions down to 283.15 K as well as Horibe et al. (42) for NaCl solutions down to 263.15 K. For the qualitative verification of the prepared aqueous inorganic salt solutions (correct molality, possible precipitation of the used salt), density measurements were carried out, which were additionally included in the work. The data represented in this work complement the already existing data and are important for model validation in general and especially in atmospheric science. (24,25,43)

2. Experimental Methods

Click to copy section linkSection link copied!

2.1. Materials

All salts used are listed in Table 1 and were used without further purification. LiCl is very hygroscopic and was first dried in a desiccator under vacuum. Mass stability was achieved after 24 days (576 h), as shown in Figure S1 in Supporting Information (SI). Thereafter, LiCl and all other salts were stored in tightly closed bottles, additionally sealed with Parafilm (Parafilm M) in a desiccator together with a drying agent to ensure a dry environment. The sealing with Parafilm also avoids possible water loss of the MgCl₂ × 6H₂O in the presence of a drying agent. The used water was fully demineralized. Additionally, the water was distilled until the conductivity was below 2.5 μS·cm^–1.

Table 1. Inorganic Salts Used for Density and Surface Tension Measurementsa

chemical	CAS	supplier	purity in mass fraction w
KCl	7447-40-7	Merck	>99.0%
LiCl	7447-41-8	Fluka	>99.0%
MgCl₂ × 6H₂O	7791-18-6	Merck	>99.0%
NaBr	7647-15-6	Riedel de Haen	>99.0%
NaCl	7647-14-5	VWR	99.9%
NaI	7681-82-5	Fluka/Merck	>99.0%/99.99%
Na₂SO₄	7757-82-6	Merck	99.99%

^{^a}

The purity values are provided by the respective supplier.

2.2. Experimental Procedure

The aqueous salt solutions were prepared gravimetrically. The concentration is given as the molality. For the calculation of the molality values of MgCl₂ x 6H₂O solutions, the proportionate mass of the six water molecules per ion pair was added to the mass of the weighed water as solvent. Thus, the molality concerns only the salt and not the hydrate. The concentration range lies between 0.1 and 5 mol·kg^–1 (up to 1 mol·kg^–1 for Na₂SO₄, up to 3 mol·kg^–1 for MgCl₂, and up to 4 mol·kg^–1 for KCl). Exact concentration values are given in Tables 2 and 3. Note that the highest concentrated solution of potassium chloride and sodium sulfate is very close to the solubility limit at 293.15 K, which can lead to salting-out effects at lower temperatures. The solubility limits are summarized and compared with the highest concentration of each investigated salt in Tables S2 and S3 in SI. Such salting-out effects can be verified by density or by surface tension, discussed in the corresponding chapters. The combined standard uncertainty of the molality u_c(m) is affected by the accuracy of the balance and was obtained from error analysis (see Table S5 in SI). It amounts to u_c(m) = 0.0002 mol·kg^–1. A more detailed description can be found in Chapter S6 in the SI.

Table 2. Experimental Values of the Density ρ of Aqueous Salt Solutions as a Function of Molality m and Temperature T at a Pressure p = 100,000 Paa

		ρ/kg·m^–3
salt	m/mol·kg^–1	278.15 K	283.15 K	288.15 K	293.15 K
NaCl	0.096	1004.16	1003.81	1003.13	1002.18
	0.203	1008.75	1008.31	1007.57	1006.55
	0.463	1019.73	1019.09	1018.16	1017.01
	0.733	1030.88	1030.04	1028.96	1027.68
	0.984	1040.83	1039.83	1038.62	1037.21
	1.498	1060.51	1059.24	1057.80	1056.18
	1.987	1078.58	1077.08	1075.44	1073.62
	2.973	1112.86	1111.02	1109.05	1106.98
	4.015	1146.70	1144.55	1142.32	1140.01
	5.005	1176.23	1173.87	1171.46	1168.97
NaBr	0.116	1009.42	1009.04	1008.35	1007.37
	0.203	1016.45	1015.99	1015.21	1014.16
	0.464	1036.96	1036.27	1035.30	1034.08
	0.752	1059.23	1058.30	1057.13	1055.71
	0.988	1077.64	1076.52	1075.19	1073.63
	1.495	1114.24	1112.78	1111.13	1109.30
	2.994	1217.04	1214.76	1212.39	1209.88
	3.971	1278.85	1276.17	1273.41	1270.62
	5.046	1343.76	1340.69	1337.55	1334.43
NaI	0.111	1013.00	1012.61	1011.89	1010.89
	0.143	1016.80	1016.37	1015.63	1014.58
	0.197	1022.63	1022.14	1021.34	1020.27
	0.513	1057.92	1057.10	1055.99	1054.66
	0.530	1060.77	1059.93	1058.80	1057.46
	0.747	1082.94	1081.80	1080.43	1078.89
	0.994	1111.85	1110.54	1109.01	1107.30
	0.997	1110.05	1108.75	1107.23	1105.52
	1.530	1164.64	1162.89	1160.94	1158.88
	2.085	1219.62	1217.44	1215.11	1212.64
	2.772	1286.16	1283.48	1280.71	1277.84
	3.833	1373.57	1370.34	1367.02	1363.64
	4.664	1450.34	1446.64	1442.93	1439.17
LiCl	0.106	1002.76	1002.45	1001.81	1000.89
	0.202	1005.01	1004.68	1004.02	1003.07
	0.499	1012.17	1011.74	1011.01	1010.01
	0.748	1018.00	1017.49	1016.71	1015.70
	1.014	1024.03	1023.46	1022.62	1021.56
	1.561	1036.96	1036.25	1035.32	1034.18
	2.363	1053.70	1051.84	1051.83	1050.62
	2.985	1066.20	1065.28	1064.20	1062.98
	4.141	1088.05	1087.01	1085.86	1084.59
	4.920	1101.73	1100.65	1099.45	1098.16
KCl	0.118	1005.74	1005.38	1004.71	1003.74
	0.204	1009.95	1009.54	1008.80	1007.81
	0.541	1025.76	1025.12	1024.21	1023.07
	0.752	1035.32	1034.55	1033.54	1032.32
	1.011	1046.74	1045.84	1044.72	1043.34
	1.409	1063.70	1062.61	1061.33	1059.85
	1.930	1084.99	1083.71	1082.25	1080.59
	3.086	1132.30	1130.66	1128.88	1127.03
	4.023	1160.65	1158.84	1156.93	1154.87
MgCl₂	0.099	1007.97	1007.62	1006.96	1006.02
	0.212	1016.91	1016.47	1015.73	1014.75
	0.487	1038.09	1037.45	1036.57	1035.45
	0.698	1053.56	1052.80	1051.82	1050.63
	0.942	1071.26	1070.37	1069.28	1068.01
	1.314	1096.66	1095.61	1094.40	1093.04
	1.633	1117.92	1116.77	1115.46	1114.02
	2.301	1158.40	1158.48	1157.05	1155.50
	2.776	1187.98	1186.56	1185.05	1183.46
	3.201	1211.84	1210.35	1208.79	1207.15
Na₂SO₄	0.088	1011.89	1011.43	1010.66	1009.65
	0.235	1030.56	1029.83	1028.84	1027.60
	0.495	1063.55	1062.35	1060.39	1058.54
	0.730	1089.89	1088.52	1086.95	1085.25
	0.930	1110.96	1109.34	1107.56	1105.63

^{^a}

The combined standard uncertainties are as follows: molality values u_c(m) = 0.0002 mol·kg^–1 and density values u_c(ρ) = 0.34 kg·m^–3. The standard uncertainty of the temperature is u(T) = 0.01 K. See Chapter S6 in SI for more details.

Table 3. Experimental Values of the Surface Tension γ of Aqueous Salt Solutions as a Function of Molality m and Temperature T at a Pressure p = 100,000 Paa

		γ/mN·m^–1
	m/mol·kg^–1	263.15 K	268.15 K	271.15 K	273.15 K	278.15 K	283.15 K	288.15 K	293.15 K
NaCl	0.096			75.49	75.29	74.46	73.68	73.04	72.16
	0.203		76.55	76.06	75.73	74.93	74.20	73.47	72.56
	0.463		77.31	76.94	76.56	75.64	75.05	74.15	73.25
	0.733		77.62	77.31	76.91	75.85	75.17	74.70	73.39
	0.984		78.43	77.93	77.64	76.70	75.94	74.94	73.78
	1.498	80.31	79.44	78.91	78.53	77.65	76.62	75.75	74.46
	1.987		78.65	78.10	77.89	76.97	76.47	75.66	75.00
	2.973	79.83	79.23	78.90	78.42	77.85	77.24	76.34	75.55
	4.015	82.48	81.88	81.53	81.27	80.55	80.09	79.28	78.30
	5.005	83.51	83.15	82.92	82.81	82.14	81.55	80.69	79.90
NaBr	0.116			75.96	75.59	74.73	73.96	72.91	72.29
	0.203		76.48	75.99	75.68	74.81	74.04	73.17	72.57
	0.464		77.06	76.60	76.34	75.39	74.71	73.83	72.69
	0.752		77.27	76.67	76.39	75.35	74.78	73.79	72.83
	0.988		77.58	76.97	76.80	76.03	75.32	74.41	73.42
	1.495	78.65	78.18	77.70	77.43	76.52	75.64	74.70	73.42
	2.994	79.66	79.11	78.64	78.27	77.55	76.79	75.92	75.10
	3.971	80.51	80.22	79.82	79.59	78.78	78.03	77.40	76.35
	5.046	81.50	81.11	80.87	80.61	80.05	79.46	78.73	77.84
NaI	0.111			76.17	75.65	74.78	73.86	72.89	71.67
	0.143		75.54	75.21	75.00	74.02	73.61	72.87	71.91
	0.197		76.24	75.76	75.44	74.65	73.91	73.05	72.03
	0.513		76.59	76.21	76.06	75.22	74.60	73.71	72.78
	0.530		77.16	76.78	76.46	75.60	74.95	74.09	73.04
	0.747		76.91	76.45	76.05	75.18	74.37	73.46	72.53
	0.994		76.43	76.00	75.69	75.06	74.27	73.41	72.75
	0.997		77.23	76.78	76.34	75.64	74.86	73.90	72.99
	1.530	77.00	76.49	75.98	75.81	75.08	74.39	73.63	72.71
	2.085	77.28	76.60	76.20	75.80	75.16	74.46	73.51	72.66
	2.772	76.66	76.08	75.70	75.51	75.04	74.45	73.84	73.01
	3.833	76.94	76.34	75.96	75.75	75.05	74.40	73.66	72.71
	4.664	77.40	76.79	76.48	76.26	75.39	74.99	74.21	73.29
LiCl	0.106			75.90	75.51	74.51	73.89	72.93	72.14
	0.202		76.59	76.08	75.83	75.08	74.48	73.61	72.72
	0.499		78.83	78.20	77.94	77.14	76.53	75.70	75.17
	0.748		77.83	77.46	77.12	76.07	75.52	74.64	73.75
	1.014		78.78	78.21	78.03	77.30	76.55	75.72	75.01
	1.561	78.91	78.35	77.94	77.75	76.76	75.98	75.20	74.30
	2.363	79.39	78.97	78.56	78.29	77.63	76.93	76.03	75.00
	2.985	80.94	80.52	80.17	79.88	79.11	78.65	77.83	77.12
	4.141	82.15	81.78	81.39	81.11	80.38	80.01	79.37	78.54
	4.920	84.03	83.67	83.47	83.32	82.60	82.03	81.41	80.59
KCl	0.118			76.11	75.89	74.94	74.38	73.63	72.90
	0.204		77.33	76.94	76.58	75.71	75.06	74.15	73.40
	0.541		77.25	76.82	76.72	75.84	75.21	74.41	73.60
	0.752		78.34	77.97	77.74	76.83	76.24	75.66	74.89
	1.011		77.53	77.14	76.83	75.97	75.31	74.39	73.42
	1.409	79.18	78.53	78.09	77.91	77.10	76.46	75.65	75.03
	1.930	79.21	78.64	78.27	78.01	77.37	76.74	75.97	75.22
	3.086	80.37	79.91	79.55	79.39	78.66	78.00	77.44	76.80
	4.023	81.45	80.46	80.31	80.39	79.87	79.25	78.48	77.87
MgCl₂	0.099			77.33	77.01	76.26	75.54	74.82	74.23
	0.212		77.48	76.95	76.67	75.97	75.27	74.62	73.86
	0.487		77.06	77.08	76.73	75.79	75.13	74.35	73.70
	0.698		77.82	77.27	77.00	76.09	75.30	74.46	73.66
	0.942		78.96	78.44	78.19	77.59	76.89	76.00	75.46
	1.314	80.74	80.38	79.86	79.63	78.80	78.13	77.46	76.61
	1.633	81.53	80.96	80.65	80.36	79.57	79.07	78.23	77.59
	2.301	84.48	83.83	83.47	83.04	82.47	81.87	81.21	80.73
	2.776	85.83	85.30	84.98	84.69	83.90	83.31	82.75	82.23
	3.201	87.62	87.03	86.80	86.50	85.80	85.35	84.56	83.89
Na₂SO₄	0.088			75.90	75.45	74.80	74.21	73.54	72.71
	0.235		77.57	77.07	76.84	75.96	75.32	74.53	73.39
	0.495		76.56	76.15	75.88	75.32	74.74	74.10	73.50
	0.730		78.68	78.35	77.92	77.03	76.24	75.33	74.53
	0.930		78.92	78.80	78.59	78.00	77.35	76.47	75.63

^{^a}

The combined standard uncertainty of the molality values amounts to u_c(m) = 0.0002 mol·kg^–1. The combined standard uncertainty of the surface tension values, u_c(γ), are given in Table S6 in SI. The standard uncertainty of the temperature is u(T) = 0.1 K. See Chapter S6 in SI for more details.

2.3. Density Measurements

The density of the aqueous salt solutions was measured as a function of temperature with the density meter DMA 4500 from Anton Paar GmbH by using the oscillating U-tube method. The measurements were carried out at 278.15, 283.15, 288.15, and 293.15 K. The accuracy of the density measurement amounts to ± 0.01 kg·m^–3 and the internal temperature control is better than ± 0.01 K. Both values are given by the supplier. Calibration of the density meter was done with air and distilled water by the supplier, and it was verified before each measurement series with distilled water with a conductivity below 2.5 μS·cm^–1. Each solution was measured two times and the values were averaged. The combined standard uncertainty amounts to u_c(ρ)= 0.34 kg·m^–3 (cf., Chapter 6.2 in SI). The results are summarized in Table 2.

2.4. Surface Tension Measurements

The surface tension was measured as a function of temperature as well with the tensiometer SITA online t60 with an upgrade to t100 from SITA GmbH using the bubble pressure method (differential pressure). The capillaries are made of polyetheretherketone (PEEK) and exhibit a diameter of 0.8 mm. Ambient air is dried by passing through a desiccant cartridge at the air inlet before it is pressed through the capillary into the liquid. During bubble formation, the bubble pressure is measured to calculate the surface tension. The maximum bubble formation time amounts to 100 s. To avoid bubble coalescence phenomena, the bubble interval ranges from 1.5 s for a minimum bubble formation time of 1 s to >150 s for a maximum bubble formation time of 100 s. (40) The measurements were performed at 263.15, 268.15, 271.15, 273.15, 278.15, 283.15, 288.15, and 293.15 K. Calibration of the tensiometer was done at 293.15 K with distilled water with a conductivity below 2.5 μS·cm^–1 before each temperature-dependent measurement series. The temperature was controlled by a thermostatic bath with an accuracy of ± 0.1 K. The accuracy of the surface tension measurements is given by a value of 0.1 mN·m^–1. Each solution was measured two times so that two measurement series were obtained (Figure S2 in SI). The last five values of each measurement series were averaged. The exact procedure is explained in Chapter S4 in the SI. The combined standard uncertainties of the surface tension values u_c(γ) are given in Table S6 in the SI. A more detailed description of error analysis can be found in Chapter S6.3 in the SI.

3. Results and Discussion

Click to copy section linkSection link copied!

3.1. Density

Temperature and salt concentration are the main influencing factors of the density of aqueous salt solutions. The density ρ of the different concentrated aqueous salt solutions was measured as a function of temperature from 278.15 to 293.15 K with an increment of 5 K as presented in Table 2. As expected, the density decreases with increasing temperature (not shown as a diagram). With increasing temperature, the molecular packing, influenced by intermolecular interactions (solvent–solvent and solute–solvent), is reduced due to enhanced molecular mobility in an expanded volume, resulting in a decrease in density. On the other hand, the density increases proportionally with the salt concentration within the investigated temperature range. This behavior is shown in Figure S3 in the SI for the highest and lowest studied temperatures. No deviation from trend was observed, from which one can conclude that there could not have been any precipitation of the used salt between 278.15 and 293.15 K. The observed trend is in good agreement with the expectations based on the molar mass of the salt. A comparison with literature is shown for NaCl at 293.15 K in Figure 1. The density data, received with the same measurement method, agree very well for NaCl (cf. Figure 1), as well as NaBr, LiCl, KCl, MgCl₂, and Na₂SO₄ at 293.15 K, respectively. (44−46) Further graphical comparisons, like in Figure 1, are given in Figures S18 and S19 in the SI. For NaCl, NaBr, LiCl, and KCl, the density values published in Shah et al. (41) are lower, resulting from density measurement with a pycnometer, as a quite different measurement method from that used in this study.

Figure 1. Density ρ of aqueous salt solutions of NaCl as a function of molality m at a temperature T = 293.15 K and at a pressure p = 100,000 Pa for: solid line and × own data (cf. Table 2) in comparison with data from literature: blue ● Hoffert et al., (47) red ▲ Rogers and Pitzer, (48) and gray ◆ Shah et al. (41) Note that the reference data from Rogers and Pitzer are given as specific volumes and were converted into density for comparison.

3.2. Surface Tension

Like in the case of the density, temperature and salt concentration are also the major influencing factors of the surface tension of the aqueous inorganic salt solutions. For all salt solutions, surface tension measurements were possible down to 271.15 K without freezing of the solution. Measurements at 268.15 K were possible for m > 0.14 mol·kg^–1 and at 263.15 K for m > 1.3 mol·kg^–1, respectively. The data are summarized in Table 3 and the corresponding uncertainty values are listed in Table S6 in the SI. Details concerning the error analysis can be found in Chapter S6.3 in the SI.

In Figure 2 surface tension of 1, 2, and 3 mol·kg^–1 NaCl solution as a function of temperature taken from Table 3 is shown in comparison with data from literature at similar molalities. (42) Horibe et al. applied the differential capillary-rise method to measure the static surface tension. (42) To the best of our knowledge, these are the only published surface tension data of aqueous inorganic salt solutions at temperatures below 273.15 K. For all six data sets in Figure 2 the gradient of the surface tension (dγ/dT)_p, m is similar. Obviously, our values are usually lower than those from Horibe et al., which is due to the different measurement methods. In the case of aqueous inorganic salt solutions, the dynamic surface tension is slightly lower than the static one. In addition, the initial salt content of the water used influences the surface tension. We used water with a very low conductivity (cf. Chapter 2.1). Horibe et al. did not provide any detailed information about sample preparation, especially on water purity. Furthermore, small deviations in the temperature and concentration can also lead to deviations in surface tension, but this effect is considered to be less significant.

Figure 2. Surface tension γ of aqueous salt solutions of NaCl as a function of temperature T at a pressure p = 100,000 Pa for own data at: ■ 2.994 mol·kg^–1, blue ● 1.997 mol·kg^–1, gray ▲ 0.984 mol·kg^–1 (cf. Table 3) and data from literature (42) at: □ 3.020 mol·kg^–1, blue ○ 1.901 mol·kg^–1, gray △ 0.901 mol·kg^–1. The concentrations of the reference data are given in mass fractions and were converted into molality for comparison (cf. Chapter S1 in the SI).

In the following section, we compare our surface tension values with data from literature that were measured under similar conditions (cf. Figures S20 and S21 in SI for graphical comparisons). It has to be mentioned that we concentrated on a temperature of 293.15 K and a concentration of approximately 1 mol·kg^–1 for more clarity. Matubayasi et al. published surface tension data for a lot of aqueous salt solutions. (30−32) All data were received via the drop volume method. So, the surface tension amounts to ≈ 74.3 mN·m^–1 for NaCl, ≈ 73.8 mN·m^–1 for NaI, ≈ 74.2 mN·m^–1 for LiCl, as well as ≈ 74.6 mN·m^–1 for Na₂SO₄ (here at 0.9 mol·kg^–1). Jarvis and Sheiman (49) measured surface tensions with the duNouy ring method at 298.15 K and obtained values as follows: ≈ 74.0 mN·m^–1 for NaCl, ≈ 73.8 mN·m^–1 for NaBr, ≈ 73.5 mN·m^–1 for NaI, ≈ 73.8 mN·m^–1 for LiCl, ≈ 73.5 mN·m^–1 for KCl, ≈ 75.6 mN·m^–1 for MgCl₂, and ≈ 75.0 mN·m^–1 for Na₂SO₄. Since the data from Matubayasi et al. as well as Jarvis and Sheiman are only available in graphical and not tabular form, the values were extracted from the graphs. The surface tension data in Shah et al. (41) were conducted with the stalagmometer method and amounts to 73.96 mN·m^–1 for NaCl, 73.81 mN·m^–1 for NaBr, 74.08 mN·m^–1 for LiCl, and 74.94 mN·m^–1 for KCl. In the work of Ozdemir et al. a sessile bubble tensiometer was used for surface tension measurements at a temperature of 296.15 K. (36) The values amounts to 74.05 mN·m^–1 for NaCl and 73.77 mN·m^–1 for KCl. Note that the concentration is given there as molarity M but a conversion into molality was omitted because of the very low difference in the numerical values at the referred temperatures since water is used as a solvent. Our values are lower by 1.5 mN·m^–1 in maximum except for LiCl and Na₂SO₄, for which our values are larger. Possible reasons for the deviations are already discussed in Figure 2 in the previous section. In case of LiCl a possible explanation can be found in the drying procedure of the hygroscopic salt (see Chapter 2.1 above and Chapter S3 in SI). Since LiCl contains small amounts of water, the real LiCl concentration is lower, and therefore, also the surface tension should be lower. In both articles it is mentioned that the salts were used as received and no further information regarding the preparation of LiCl could be found. (31,41) In the case of Na₂SO₄ the small concentration differences of the compared solutions may be the explanation for the deviations in surface tension values. For NaI solutions, our measured surface tension values are lower and also show a weaker concentration dependence than the literature data. Regarding to our experiments there is no evidence of contamination of the solutions or of incorrect measurements. Possible explanations can be found in different sample preparation as well as different measurement methods as the most likely reason.

In the following section, all shown graphs represent exemplary results for NaBr solutions. The graphs for the other inorganic salts can be found in Figures S4–S12 in SI. First, Figure 3 depicts the surface tension as a function of temperature for different concentrations of NaBr solutions. Note that not all concentrations are included for better clarity. The graphs of the other salt solutions are given in Figures S4–S9 in SI in the same way. As expected, the surface tension increases linearly with decreasing temperature for all solutions. Only at the two lowest temperatures (268.15 and 263.15 K) do the values deviate slightly from linear behavior. For solutions close to the solubility limit, the decreasing solubility with decreasing temperature may be the cause. Another possible explanation is the slower surface formation during bubble growth at lower temperatures. Thus, it may be that despite the same surface age, the state of the surface is slightly different at different temperatures.

Figure 3. Surface tension γ of aqueous salt solutions of NaBr as a function of temperature T at a pressure p = 100,000 Pa: ■ 0.116 mol·kg^–1, gray ● 0.464 mol·kg^–1, ▲ 0.988 mol·kg^–1, gray ▼ 2.994 mol·kg^–1, ◆ 3.971 mol·kg^–1, gray ◀ 5.046 mol·kg^–1 (cf. Table 3).

Finally, Figure 4 again illustrates the surface tension, this time as a function of molality for all temperatures of NaBr. In general, the surface tension increases with increasing salt concentration at all temperatures, but the increase is less pronounced at 268.15 and 263.15 K. Although the highest concentration is below the solubility limit (cf. Tables S2 and S3 in SI), the surface tension at 268.15 and 263.15 K of the higher concentrated salt solutions seems a little bit too low. A similar behavior was observed for the other salt solutions (cf., Figures S10 to S12 in SI) and a possible explanation is given above in the discussion of Figure 3. Because of the weak concentration dependence of the surface tension in the case of NaI pointed out above, the scatter of data (cf. Figure S10 in SI) is more relevant for calculation of the excess surface tension and surface tension gradient than for the other salts (cf. Chapters 3.3 and 3.4). Therefore, a larger difference of these values compared to comparative data is to be expected. Due to the slight deviations of surface tension data at temperatures below 271.15 K as mentioned in the previous sections, these data were not included into calculation of the surface tension gradient and the thermodynamic quantities.

Figure 4. Surface tension γ of aqueous salt solutions of NaBr as a function of molality m at a pressure p = 100,000 Pa: Solid and dotted lines result from linear fit at ■ 293.15 K, gray ● 288.15 K, ▲ 283.15 K, gray ▼ 278.15 K, ◆ 273.15 K, gray ◀ 271.15 K, ▶ 268.15 K, gray × 263.15 K (cf. Table 3).

At low concentration of NaCl, NaBr, NaI, and LiCl solutions around 0.1 mol·kg^–1 a further distinctive feature can be observed. Here the surface tension of solution is lower than those of water, which can be extracted from Table 3 and Table S4 in SI. The latter one exhibits the surface tension of pure water at 293.15 K. Normally, the surface tension is not lowered by adding inorganic salts due to the absence of hydrophobic interactions between the ions and water molecules, which results rather in a depletion of these ions at the surface. The fact that the surface tension decreases despite the addition of small amounts of inorganic salts is known from literature as Jones–Ray effect (50−52) that occurs at typical salt concentrations lower than 0.1 mol·kg^–1 and show a minimum in surface tension at concentrations below 0.01 mol·kg^–1. (51,53,54) The Jones–Ray effect has been discussed in a very controversial way for decades. Okur et al. proposed in their articles that the Jones–Ray effect results from disturbances in the hydrogen-bond network of water induced by small amounts of inorganic salts. (54,55) Nevertheless, small amounts of surface-active organic molecules as impurity of the untreated salt can also lower the surface tension that becomes prominent in lower concentration ranges. (54) Since this effect is very small with a surface tension reduction of much less than 1 mN·m^–1, it can be assumed that the impurity with surface-active organic molecules can be only very low. Otherwise surface tension reduction would be much more concise, since such surfactants are known to be very effective at this.

3.3. Excess Surface Tension

The excess surface tension Δγ was calculated for all salt solutions with eq 9 for a temperature of 293.15 K. The results are summarized in Table S7 and plotted in Figures S16 and S17 in the SI. The excess surface tension data were linearly fitted including the value of pure water (Δγ = 0 mN·m^–1). These fits are presented in Figure 5.

Figure 5. Linear fit results of the excess surface tension Δγ of aqueous salt solutions as a function of molality m at a temperature T = 293.15 K and a pressure p = 100,000 Pa of green ─ NaCl, orange ─ NaBr, red ─ NaI, sky blue ─ LiCl, gray ─ KCl, purple ─ MgCl₂, and blue ─ Na₂SO₄. (cf. Figures S16 and S17). See Chapter 10 in the SI for more information on fitting the experimental data.

In the case of NaCl, NaBr, NaI, and LiCl, the excess surface tension also shows negative values at low concentrations (cf. Table S7 in SI). This feature was already discussed in the previous section (cf. 3.2). The negative values were not excluded from the linear fit. Therefore, our values may be slightly smaller than comparable values from the literature. As expected, dissolving inorganic salts in water leads to a general increase in surface tension, which means the excess surface tension is positive. The capability of the different inorganic salts to raise the surface tension is clearly different depending on the adsorption capacity of the salt. A lower excess surface tension value means a stronger adsorption at the air/water interface. Lowest values for a 1 mol·kg^–1 solution were received for NaI with Δγ < 0.3 mN·m^–1, and highest values for the electrolytes with one divalent ion, MgCl₂ and Na₂SO₄ with Δγ ≈ 3.0 mN·m^–1. For the other inorganic salts, the excess surface tension are between 0.7 and 2.2 mN·m^–1 for a 1 mol·kg^–1 solution. The order of the inorganic salts concerning the power of surface tension raising is in good agreement with the works of Pegram and Record, (56) as well as Weissenborn and Pugh, (39) who have collected a huge amount of experimental data from literature. Their works clearly show a stronger rise in surface tension in the case of electrolytes with divalent anions like Na₂SO₄ as well as Li₂SO₄, K₂SO₄, Cs₂SO₄, (NH₄)₂SO₄, Na₂CO₃, and K₂CO_3, (56) and an even stronger effect for electrolytes with trivalent cations like LaCl₃ or Cr(NO₃)³⁹ compared to monovalent electrolytes at similar salt concentrations. Based on our measurements, the adsorption capacity of the monovalent sodium halide salts is in the order NaI > NaBr > NaCl. This is consistent with the results from molecular dynamics simulation studies of Jungwirth and Tobias, as already mentioned above. (24) However, there are differences in the magnitude of the values, especially in the case of NaI, for which our values are much lower than those from other experimental works, like in Jarvis and Sheimann (49) or Matubaysai et al., (32) with Δγ ≈ 1.0 mN·m^–1 for a 1 mol·kg^–1 solution. Possible explanations can be found in Chapter 3.2.

3.4. Surface Tension Gradient

The change in surface tension by adding solutes to the solvent can also be expressed by the gradient (dγ/dm)_T, p, which has a similar validity to the excess surface tension but is more common in published studies. The surface tension gradient was calculated by least-squares linear regression analysis at constant temperature. Here, the value of pure water was not included because it was only measured at 293.15 K, and of course, it is not available for 271.15 K. The difference whether the values of water are included or not is far below the calculated uncertainty of the surface tension gradient. Only in the case of NaI, the difference is larger because of the scattering of the surface tension data around that of pure water, combined with the weak increase in surface tension with increasing concentration. The gradients for the different salt solutions at different temperatures are listed in Table 4. Note that the gradient was not calculated for the two lowest temperatures in this work. From Table 4, it can be clearly extracted for the monovalent electrolytes that the gradient is reduced with decreasing temperature, being in agreement with Matubayasi et al. (31,32) For MgCl₂ and Na₂SO₄, our values show a minimum, respectively.

Table 4. Surface Tension Increments of Aqueous Salt Solutions Given as Gradient (dγ/dm)_T, p at Temperature T at a Pressure p = 100,000 Paa

	(dγ/dm)_T, p/mJ·kg·m^–2·mol^–1
T/K	NaCl	NaBr	NaI	LiCl	KCl	MgCl₂	Na₂SO₄
271.15	1.321 ± 0.129	0.966 ± 0.034	0.026 ± 0.090	1.328 ± 0.138	0.969 ± 0.104	3.400 ± 0.227	3.203 ± 1.114
273.15	1.345 ± 0.131	0.972 ± 0.044	0.056 ± 0.081	1.346 ± 0.144	1.036 ± 0.103	3.377 ± 0.212	3.311 ± 1.122
278.15	1.402 ± 0.118	1.031 ± 0.042	0.090 ± 0.082	1.387 ± 0.149	1.132 ± 0.101	3.301 ± 0.207	3.372 ± 0.948
283.15	1.448 ± 0.106	1.043 ± 0.045	0.137 ± 0.075	1.422 ± 0.149	1.124 ± 0.102	3.268 ± 0.191	3.247 ± 0.909
288.15	1.419 ± 0.104	1.100 ± 0.049	0.173 ± 0.070	1.475 ± 0.156	1.156 ± 0.120	3.278 ± 0.195	3.003 ± 0.798
293.15	1.462 ± 0.083	1.077 ± 0.045	0.199 ± 0.078	1.463 ± 0.179	1.203 ± 0.134	3.426 ± 0.156	3.177 ± 0.523

^{^a}

The standard uncertainty of the temperature amounts to u(T) = 0.1 K. The standard uncertainties of the gradient values u((dγ/dm)_T, p) are taken from least-squares linear regression analysis.

Positive values of the surface tension gradient mean that the solvated ions of the salts are depleted at the air/water interface compared with the bulk phase of the solution. The distribution of anions and cations in the interfacial region can be different, as shown in several molecular dynamics and other theoretical studies, (24,57−61) as well as with X-ray photoelectron spectroscopy (62,63) and ultraviolet second harmonic generation spectroscopy. (64) If this is the case, then the surface properties are dominated by one of the ion types. Jungwirth and Tobias simulated the air/water interface of different aqueous sodium halide solutions at 293.15 K and were the first to publish the results with new insights into the interfacial structure of electrolyte solutions. (24) They could show that smaller, nonpolarizable anions like fluoride or chloride are depleted and larger, polarizable anions like bromide or, in particular, iodide are enriched in the interfacial region. Transferred to the gradient values, it means that it is lower for NaI solutions than for NaCl solutions. This can be seen in Table 4. However, the value for the NaI solution is extremely low, even if the value of water was included in the calculation of the gradient. Nevertheless, the value of NaI should be closer to the value of the NaBr solution, since bromide is also supposed to accumulate at the air/water interface. (24) In a study of Sun et al., a slightly different result was obtained from molecular simulation studies of the same salts. (60) The density profile of bromide in the interfacial region is similar to that of chloride, and bromide seems not so strongly enriched as proposed in earlier studies referenced above. This may be an explanation for our gradient values of NaBr solutions that are closer to the values of NaCl solutions than to those of NaI solutions.

Several surface tension increment values at approximately 293.15 K were extracted from the literature and are summarized in Table 5 for comparison with our data. Note that the data received with the maximum bubble pressure method (mBPM) refer to molarity. These data were also not converted into molality because of the same reasons already given in Chapter 3.2. The summary in Table 5 shows that the data differ. The order of the data is also not always the same, as can be seen based on the example of LiCl and KCl. In the works of Weissenborn and Pugh (39,40) the value of LiCl is larger than for KCl, as in our data, while in Matubayasi et al., (31) the opposite is the case. Considering the uncertainties, our data are in good accordance with the literature data, except for NaI, which is discussed in the previous section and in Chapter 3.2.

Table 5. Surface Tension Increment of Aqueous Salt Solutions Given as Gradient (dγ/dm)_T, p Taken from Literaturea

	(dγ/dm)_T, p/mJ·kg·m^–2·mol^–1
method	NaCl	NaBr	NaI	LiCl	KCl	MgCl₂	Na₂SO₄
mBPMb	2.08	1.83	1.23	1.98	1.85	4.06	2.90
mBPMc	1.76	1.71	-	-	1.68	3.73	2.99
DVd	1.70	-	-	1.58	1.59	-	2.66
DVe	-	-	-	1.38	1.49	-	-
DVf	1.41	1.19	0.97	-	-	-	-
WPg	1.75	-	1.21	-	1.65	-	-

^{^a}

Note that the concentration in b and c is given in molarity and is not converted into molality. For this, the gradient is (dγ/dM)_T, p/mJ·L·m^–2·mol^–1. A conversion into molalities was omitted. The abbreviations mean as follows: mBPM – maximum bubble pressure method, DV – drop volume method, WP – Wilhelmy plate method

^{^b}

Data from Weissenborn and Pugh (39,40) at T = 294.15–301.15 K and for 0.05–1 mol·l^–1 solutions.

^{^c}

Data from Henry et al. (38) at T = 293.15 K and for 0.5 to 3 mol·l^–1 solutions.

^{^d}

Data from Aveyard and Saleem (37) at T = 293.15 K and 0.1–1 mol·kg^–1 NaCl solutions, 0.2–1.5 mol·kg^–1 KCl solutions, 0.2–1.0 mol·kg^–1 Na₂SO₄ solutions.

^{^e}

Data from Matubayasi et al. (31) at T = 293.15 K and 0.1–1 mol·kg^–1 solutions.

^{^f}

Data from Matubayasi et al. (32) at T = 293.15 K and 0.1–1 mol·kg^–1 solutions.

^{^g}

Data from Johansson and Eriksson (35) at T = 298.15 K and 0.1–1 mol·kg^–1 NaCl and NaI solutions, 0.1–1.5 mol·kg^–1 KCl solutions.

3.5. Thermodynamic Quantities of Surface Formation

The surface excess entropy Δs^σ and surface excess energy Δu^σ given in Table 6 were estimated by least-squares linear regression analysis of the temperature-dependent surface tension data (cf. eq 8 and description in Chapter 1). As described above, the values at 263.15 and 268.15 K were not included in the regression analysis. The surface excess enthalpy Δh^σ at a temperature of 293.15 K was calculated with eq 6. First of all, it should be noted that the changes in the excess quantities are associated with the adsorption capacity of the dissolved substance.

Table 6. From Experimental Data Calculated Values of Surface Excess Entropy Δs^σ, Surface Excess Energy Δu^σ, and Surface Excess Enthalpy Δh^σ of Aqueous Salt Solutions as a Function of Molality m at a Pressure p = 100,000 Paa

salt	m/mol·kg^–1	Δs^σ/mJ·K^–1·m^–2		Δu^σ/mJ·m^–2		Δh^σ/mJ·m^–2
NaCl	0.096	0.1509	±0.0038	116.4433	±1.0825	44.2345	±1.1434
	0.203	0.1560	±0.0016	118.3353	±0.4433	45.7342	±0.4778
	0.463	0.1635	±0.0032	121.2163	±0.9061	47.9206	±0.9609
	0.733	0.1638	±0.0097	121.5607	±2.7389	48.0049	±2.8731
	0.984	0.1816	±0.0050	127.1595	±1.4185	53.2297	±1.4980
	1.498	0.1944	±0.0063	131.6060	±1.7731	56.9840	±1.8686
	1.987	0.1413	±0.0031	116.4144	±0.8676	41.4261	±0.9183
	2.973	0.1433	±0.0055	117.6466	±1.5518	42.0164	±1.6331
	4.015	0.1387	±0.0067	119.1521	±1.8869	40.6633	±1.9813
	5.005	0.1366	±0.0066	120.0873	±1.8613	40.0578	±1.9536
NaBr	0.116	0.1667	±0.0040	121.0866	±1.1281	48.8646	±1.1929
	0.203	0.1582	±0.0037	118.8695	±1.0330	46.3885	±1.0924
	0.464	0.1725	±0.0051	123.4361	±1.4396	50.5688	±1.5173
	0.752	0.1684	±0.0037	122.2627	±1.0379	49.3651	±1.0997
	0.988	0.1583	±0.0057	119.9938	±1.5920	46.4065	±1.6753
	1.495	0.1865	±0.0069	128.3121	±1.9384	54.6743	±2.0400
	2.994	0.1559	±0.0034	120.8511	±0.9468	45.6965	±1.0028
	3.971	0.1511	±0.0055	120.8056	±1.5559	44.3081	±1.6375
	5.046	0.1309	±0.0059	116.3658	±1.6608	38.3648	±1.7451
NaI	0.111	0.1970	±0.0046	129.5423	±1.2814	57.7419	±1.3554
	0.143	0.1445	±0.0069	114.3908	±1.9428	42.3523	±2.0393
	0.197	0.1669	±0.0040	121.0629	±1.1118	48.9205	±1.1754
	0.513	0.1537	±0.0052	117.9655	±1.4626	45.0625	±1.5403
	0.530	0.1616	±0.0044	120.5451	±1.2294	47.3609	±1.2983
	0.747	0.1698	±0.0021	122.3612	±0.5877	49.7820	±0.6303
	0.994	0.1475	±0.0040	115.9751	±1.1272	43.2261	±1.1899
	0.997	0.1638	±0.0047	121.0817	±1.3116	48.0146	±1.3850
	1.530	0.1447	±0.0049	115.2674	±1.3670	42.4283	±1.4400
	2.085	0.1554	±0.0050	118.3054	±1.3932	45.5624	±1.4684
	2.772	0.1181	±0.0063	107.7911	±1.7801	34.6292	±1.8679
	3.833	0.1419	±0.0055	114.4380	±1.5468	41.5853	±1.6277
	4.664	0.1379	±0.0054	113.8483	±1.5085	40.4203	±1.5869
LiCl	0.106	0.1711	±0.0026	122.2650	±0.7367	50.1435	±0.7845
	0.202	0.1512	±0.0038	117.1506	±1.0718	44.3276	±1.1322
	0.499	0.1410	±0.0043	116.4026	±1.2022	41.3199	±1.2673
	0.748	0.1677	±0.0035	122.9118	±0.9752	49.1579	±1.0330
	1.014	0.1468	±0.0028	118.0374	±0.7904	43.0213	±0.8390
	1.561	0.1656	±0.0034	122.8650	±0.9468	48.5391	±1.0036
	2.363	0.1565	±0.0077	121.0421	±2.1624	45.8661	±2.2704
	2.985	0.1359	±0.0031	116.9841	±0.8649	39.8466	±0.9156
	4.141	0.1210	±0.0038	114.1376	±1.0780	35.4588	±1.1358
	4.920	0.1303	±0.0034	118.8528	±0.9480	38.2061	±1.0018
KCl	0.118	0.1462	±0.0020	115.7361	±0.5664	42.8459	±0.6050
	0.204	0.1581	±0.0029	119.7337	±0.8220	46.3380	±0.8728
	0.541	0.1459	±0.0027	116.4182	±0.7480	42.7572	±0.7941
	0.752	0.1361	±0.0036	114.8167	±1.0035	39.9121	±1.0600
	1.011	0.1599	±0.0047	120.4518	±1.3246	46.8833	±1.3972
	1.409	0.1404	±0.0027	116.1949	±0.7488	41.1679	±0.7943
	1.930	0.1323	±0.0039	114.0987	±1.1000	38.7942	±1.1608
	3.086	0.1253	±0.0018	113.5204	±0.5017	36.7453	±0.5359
	4.023	0.1146	±0.0093	111.5716	±2.6279	33.5971	±2.7514
MgCl₂	0.099	0.1419	±0.0030	115.7444	±0.8339	41.5889	±0.8835
	0.212	0.1418	±0.0011	115.4515	±0.3026	41.5779	±0.3294
	0.487	0.1540	±0.0039	118.7758	±1.1106	45.1433	±1.1725
	0.698	0.1642	±0.0019	121.7893	±0.5403	48.1280	±0.5795
	0.942	0.1369	±0.0046	115.5453	±1.2882	40.1329	±1.3578
	1.314	0.1424	±0.0033	118.4270	±0.9261	41.7465	±0.9800
	1.633	0.1361	±0.0007	117.5042	±0.1914	39.9118	±0.2132
	2.301	0.1197	±0.0036	115.7778	±1.0006	35.0887	±1.0550
	2.776	0.1221	±0.0026	117.9685	±0.7405	35.7913	±0.7841
	3.201	0.1272	±0.0030	121.2133	±0.8465	37.2762	±0.8955
Na₂SO₄	0.088	0.1383	±0.0036	113.3197	±1.0194	40.5521	±1.0765
	0.235	0.1600	±0.0061	120.4811	±1.7043	46.9052	±1.7933
	0.495	0.1175	±0.0025	107.9805	±0.7085	34.4392	±0.7501
	0.730	0.1648	±0.0023	122.8768	±0.6640	48.3184	±0.7037
	0.930	0.1407	±0.0070	117.0263	±1.9795	41.2489	±2.0777

^{^a}

The surface excess enthalpy was calculated for a temperature of 293.15 K. The combined standard uncertainty of the molality values amounts to u_c(m) = 0.0002 mol·kg^–1. The combined standard uncertainties of the surface excess enthalpy u_c(Δh^σ) are estimated via error calculation. See Chapter S6 in SI for more detail. The standard uncertainties of the surface excess entropy u(Δs^σ) and the surface excess energy u(Δu^σ) are taken from least-squares linear regression analysis.

The surface excess entropy is plotted for the monovalent electrolytes in Figures 6 and 7. The data of NaCl show larger variation than those for the other salts, which was also observed in the works of Matubayasi et al. (32) and Shah et al. (41) These variations may result from slight deviations in the temperature dependence of the surface tension, leading to deviations in the slope value for calculation of the surface excess entropy. Nevertheless, considering the uncertainties, a decrease in the surface excess entropy with increasing salt concentration can be observed. This is in accordance with published data and complements, at larger concentrations, the trend in the data there in a comprehensible way. (30−32,41) It should be pointed out that the decrease in surface excess entropy is much smaller than for typical surfactants, like, for example, sodium taurodeoxycholate (NaTDC), a bihydroxy bile salt. (65) Since the entropy is a quantity of disordering of a system, this is not surprising. In general, entropy increases by adding solutes to the solvent, leading to larger entropy values of solutions (bulk and surface) compared to the pure solvent. A decrease in surface excess entropy with increasing concentration means a higher degree of orientation of the molecules at the surface with an increasing number of solute molecules. Typical surfactants tend to adsorb strongly at the air/water interface, which leads to a more or less ordered arrangement of the molecules at the water surface that becomes more prominent with increasing concentration until a highly ordered surfactant film is formed at the water surface. The high degree of order of these surfactant films results from their molecular structure. Surfactants are amphiphilic molecules with a hydrophilic headgroup and a hydrophobic tail. While the interactions between the polar headgroups of the surfactants and the polar water molecules are attractive, the interactions between the hydrophobic tails and the water molecules are repulsive, leading to an orientation of the hydrophobic tails out of the surface. The water molecules also have a higher degree of orientation in the interfacial region as a result of their interaction with the polar headgroups of the surfactant molecules, which is why the surface excess entropy decreases again and can even show negative values. (27) In the case of inorganic salts, the situation at the air/water interface is already discussed in Chapter 3.4. Larger, polarizable, not fully solvated ions also adsorb at the air/water interface, leading to a larger degree of organization of water molecules with an increasing number of ions due to electrostatic interactions between them. Compared to surfactant solutions, the organization of the water molecules there occurs to a much weaker extent due to the absence of repulsive interactions between them and the ions. This can be stated by an approximately reduction of surface excess entropy from 0.16 mJ·K^–1.m^–2 for a 1 mol·kg^–1 salt solution to 0.13 mJ·K^–1.m^–2 for a 5 mol·kg^–1 salt solution in comparison to an approximately reduction from 0.16 mJ·K^–1.m^–2 for a < 1 mmol·kg^–1 NaTDC solution to <0.01 mJ·K^–1.m^–2 for a 4 mmol·kg^–1 NaTDC solution (extracted from graphs in Matubayasi et al. (65)). Smaller, nonpolarizable ions are fully solvated and are arranged in the subsurface region. They may also lead to a slightly higher degree of organization of the water molecules at the air/water interface with an increasing number of ions for the same reasons as described before. The difference between the different ions concerning the enrichment or depletion at the water surface seems to be small, so that no clear differences could be observed in the surface excess entropy data. A value of approximately 0.16 mJ·K^–1.m^–2 for a 1 mol·kg^–1 salt solution is also in good agreement with literature data. (30−32,41) Johansson and Eriksson did not directly calculate the surface excess entropy, but the slope of the temperature-dependent surface tension data provided a value of approximately −0.16 mJ·K^–1.m^–2 for NaCl, NaI, and KCl that also agrees very well with our data. (35) Conclusions concerning the dependence of the surface excess entropy on the hydration radius or polarizability of the ions cannot be drawn, because of the small differences and the larger uncertainties in the data.

Figure 6. Surface excess entropy $Δ s^{σ}$ of aqueous salt solutions as a function of molality m at a pressure p = 100,000 Pa of: ■ NaCl, ○ NaBr, gray ▲ NaI (cf. Table 6).

Figure 7. Surface excess entropy Δs^σ of aqueous salt solutions as a function of molality m at a pressure p = 100,000 Pa of: ■ NaCl (again for comparison), ○ LiCl, gray ▲ KCl (cf. Table 6).

Further thermodynamic quantities as a function of molality are represented exemplarily for NaBr in Figure 8. The graphs for the other inorganic salts can be found in Figures S13–S15 in the SI. Regarding the small number of data points, the data for Na₂SO₄ are not representative and are therefore not shown. The surface excess energy Δu^σ as well as the surface excess enthalpy Δh^σ are also given in Table 6, and the surface excess Helmholtz energy Δa^σ is equal to the surface tension (cf. eq 7). The fact that the surface excess Helmholtz energy is increasing with increasing concentration results directly from surface tension and does not need to be further discussed. The surface excess enthalpy is always lower than 60 mJ·m^–2 and decreases with increasing concentration but remains positive, which can already be concluded from the positive values of the surface excess entropy (cf. eq 6). Positive values of the surface excess enthalpy indicate that the transfer of solvated or partially solvated ions from the electrolyte solution to the air/water interface is endothermic. For typical surfactants, the decrease of surface excess enthalpy is much stronger and can reach negative values. (27) An explanation is already given in the discussion of the surface excess entropy. The surface excess energy amounts to approximately 120 mJ·m^–2 for all salt solutions and shows the weakest concentration dependence, with also a very slight decrease with increasing concentration. Thus, the adsorption of ions at the surface of aqueous inorganic salt solutions is neither particularly less favored nor particularly favored energetically. This is contrary to the adsorption behavior of typical surfactants. Like for the already discussed thermodynamic quantities, the surface excess energy in these systems can also become negative, (27) which means that the adsorption of the surfactant molecules at the water surface is energetically more favorable than their remaining in the bulk.

Figure 8. Thermodynamic quantities of aqueous salt solutions of NaBr as a function of molality m and their linear fits at a pressure p = 100,000 Pa: ▲ surface excess energy Δu^σ(cf. Table 6), gray ■ surface excess Helmholtz energy Δa^σ at T = 293.15 K (cf. Table 3), ○ surface excess enthalpy Δh^σ at T = 293.15 K (cf. Table 6). The error bars correspond to the uncertainties of Δu^σ and Δh^σ given in Table 6. The uncertainties of Δa^σ are too small to depict, but they are equal to those of the surface tension given in Table S6 in SI.

The values and the behavior of these thermodynamic quantities are in agreement with the data from Matubayasi et al. (30,31) and Shah et al. (41) It has to be mentioned that all changes of these thermodynamic quantities of the inorganic salt solutions are very small compared to surfactant solutions. (65) This can be expected based on the weak concentration dependence of the surface tension itself and the surface excess entropy due to the much weaker adsorption of the solvated or partially solvated ions at the air/water interface compared to typical surfactants, as already discussed in detail. The weaker adsorption means that no continuous or closely packed solute film forms at the interface. As a result, the changes in the excess quantities with increasing salt concentration are generally not as significant.

4. Conclusions

Click to copy section linkSection link copied!

In the present work, new experimental surface tension data of aqueous inorganic salt solutions of NaCl, NaBr, NaI, LiCl, KCl, MgCl₂, and Na₂SO₄ in an atmospherically relevant temperature range of 263.15–293.15 K were presented. The concentration range was set from 0.1 to 5 mol·kg^–1 (up to 1 mol·kg^–1 for Na₂SO₄, up to 3 mol·kg^–1 for MgCl₂, as well as up to 4 mol·kg^–1 for KCl). From these data, the excess surface tension, the surface tension gradient, and several thermodynamic quantities like surface excess entropy, surface excess energy, surface excess enthalpy, and surface excess Helmholtz energy were calculated. The concentration-dependent surface excess entropy, as a quantity giving information about the degree of ordering of the solvent molecules at the air/water interface, slightly decreases with a growing number of dissolved ions. A decrease in surface excess entropy from approximately 0.16 mJ·K^–1.m^–2 for a 1 mol·kg^–1 salt solution to 0.13 mJ·K^–1.m^–2 for a 5 mol·kg^–1 salt solution shows a very small order dependence of the water molecules on the concentration of the inorganic salt solutions compared to typical surfactants. From an energetic point of view, the adsorption of ions at the water surface is endothermic based on the positive values of the surface excess enthalpy and is not the clearly preferred process as can be extracted from the positive and nearly constant values of the surface excess energy. This can be explained by the attractive interactions between the ions and the water molecules in aqueous inorganic salt solutions. The thermodynamic quantities are in good agreement with the literature and complement this, especially for salt concentrations higher than 1 mol·kg^–1.

Supporting Information

Click to copy section linkSection link copied!

The following files are available free of charge. The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.jced.5c00470.

Conversion of mass fraction to molality (Chapter S1, Table S1); solubility of the inorganic salts (Chapter S2, Tables S2 and S3); preparation of LiCl (Chapter S3, Figure S1); estimation of the surface tension from time series (Chapter S4, Figure S2); surface tension of water including uncertainties (Chapter S5, Table S4); calculation of the combined standard uncertainty of the molality (Chapter S6.1, Table S5); calculation of the combined standard uncertainty of the density (Chapter S6.2); calculation of the combined standard uncertainty of the surface tension (Chapter S6.3, Table S6); calculation of the combined standard uncertainty of the excess surface tension (Chapter S6.4); calculation of the combined standard uncertainty of the surface excess enthalpy (Chapter S6.5); density values at 293.15 and 278.15 K (Chapter S7 and Figure S3); surface tension as a function of the temperature of NaCl, NaI, LiCl, KCl, MgCl₂, and Na₂SO₄ solution (Chapter S8 and Figures S4–S9); surface tension as a function of the molality of NaCl, NaI, LiCl, KCl, MgCl₂, and Na₂SO₄ solution (Chapter S9 and Figures S10–S12); thermodynamic quantities such as surface excess energy, surface excess Helmholtz energy, and surface excess enthalpy at 293.15 K of NaCl, NaI, LiCl, KCl, MgCl₂, and Na₂SO₄ solution (Chapter S10 and Figures S13 to S15); excess surface tension including fits for all aqueous inorganic salt solutions at 293.15 K (Chapter S11, Table S7, and Figures S16 and S17); graphical comparison of the density values with literature data (Chapter S12, Figures S18 and S19); graphical comparison of the surface tension values with literature data (Chapter S13, Figures S20 and S21) (PDF)

je5c00470_si_001.pdf (1.72 MB)

Terms & Conditions

Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html.

Author Information

Click to copy section linkSection link copied!

Corresponding Author
- Manuela Reichelt - Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstraße 2, 04103 Leipzig, Germany; https://orcid.org/0000-0002-8365-1671; Email: [email protected]
Author
- Alexandra Giermann - Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstraße 2, 04103 Leipzig, Germany
Author Contributions
The manuscript was written through the contributions of all authors. All authors have given approval to the final version of the manuscript. M. R.: Conceptualization, methodology, experiment, investigation, data evaluation, formal analysis, validation, visualization, writing – original draft, and writing – review and editing. A. G.: Experiment, investigation, data evaluation, and writing – review and editing.
Funding
The research was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) project 321027174 (Spectroscopic Characterization of Salt Dissolution in Microhydrated Cluster Ions and at the Water/Vapor Interface).
Notes
The authors declare no competing financial interest.

Acknowledgments

Click to copy section linkSection link copied!

We thank Prof. Dr. Jonas Warneke for his discussions and critical comments on the manuscript.

References

Click to copy section linkSection link copied!

This article references 65 other publications.

1
Lelieveld, J.; Crutzen, P. J.; Ramanathan, V.; Andreae, M. O.; Brenninkmeijer, C. M.; Campos, T.; Cass, G. R.; Dickerson, R. R.; Fischer, H.; de Gouw, J. A.; Hansel, A.; Jefferson, A.; Kley, D.; de Laat, A. T.; Lal, S.; Lawrence, M. G.; Lobert, J. M.; Mayol-Bracero, O. L.; Mitra, A. P.; Novakov, T.; Oltmans, S. J.; Prather, K. A.; Reiner, T.; Rodhe, H.; Scheeren, H. A.; Sikka, D.; Williams, J. The Indian Ocean experiment: widespread air pollution from South and Southeast Asia. Science 2001, 291, 1031– 1036, DOI: 10.1126/science.1057103
Google Scholar
There is no corresponding record for this reference.
2
Ramanathan, V.; Crutzen, P. J.; Lelieveld, J.; Mitra, A. P.; Althausen, D.; Anderson, J.; Andreae, M. O.; Cantrell, W.; Cass, G. R.; Chung, C. E.; Clarke, A. D.; Coakley, J. A.; Collins, W. D.; Conant, W. C.; Dulac, F.; Heintzenberg, J.; Heymsfield, A. J.; Holben, B.; Howell, S.; Hudson, J.; Jayaraman, A.; Kiehl, J. T.; Krishnamurti, T. N.; Lubin, D.; McFarquhar, G.; Novakov, T.; Ogren, J. A.; Podgorny, I. A.; Prather, K.; Priestley, K.; Prospero, J. M.; Quinn, P. K.; Rajeev, K.; Rasch, P.; Rupert, S.; Sadourny, R.; Satheesh, S. K.; Shaw, G. E.; Sheridan, P.; Valero, F. P. J. Indian Ocean Experiment: An integrated analysis of the climate forcing and effects of the great Indo-Asian haze. J. Geophys. Res. 2001, 106, 28371– 28398, DOI: 10.1029/2001JD900133
Google Scholar
There is no corresponding record for this reference.
3
Brenninkmeijer, C. A. M.; Slemr, F.; Koeppel, C.; Scharffe, D. S.; Pupek, M.; Lelieveld, J.; Crutzen, P.; Zahn, A.; Sprung, D.; Fischer, H.; Hermann, M.; Reichelt, M.; Heintzenberg, J.; Schlager, H.; Ziereis, H.; Schumann, U.; Dix, B.; Platt, U.; Ebinghaus, R.; Martinsson, B.; Ciais, P.; Filippi, D.; Leuenberger, M.; Oram, D.; Penkett, S.; van Velthoven, P.; Waibel, A. Analyzing atmospheric trace gases and aerosols using passenger aircraft. EOS Trans. Am. Geophys. Union 2005, 86, 77– 83, DOI: 10.1029/2005EO080001
Google Scholar
There is no corresponding record for this reference.
4
Park, S. S.; Bae, M.-S.; Schauer, J. J.; Kim, Y. J.; Yong Cho, S.; Jai Kim, S. Molecular composition of PM2.5 organic aerosol measured at an urban site of Korea during the ACE-Asia campaign. Atmos. Environ. 2006, 40, 4182– 4198, DOI: 10.1016/j.atmosenv.2006.02.012
Google Scholar
There is no corresponding record for this reference.
5
Ansmann, A.; Petzold, A.; Kandler, K.; Tegen, I.; Wendisch, M.; Müller, D.; Weinzierl, B.; Müller, T.; Heintzenberg, J. Saharan Mineral Dust Experiments SAMUM–1 and SAMUM–2: what have we learned?. Tellus B: Chem. Phys. Meteorol. 2011, 63, 403, DOI: 10.1111/j.1600-0889.2011.00555.x
Google Scholar
There is no corresponding record for this reference.
6
Kandler, K.; Schütz, L.; Jäckel, S.; Lieke, K.; Emmel, C.; Müller-Ebert, D.; Ebert, M.; Scheuvens, D.; Schladitz, A.; Šegvié, B.; Wiedensohler, A.; Weinbruch, S. Ground-based off-line aerosol measurements at Praia, Cape Verde, during the Saharan Mineral Dust Experiment: microphysical properties and mineralogy. Tellus B: Chem. Phys. Meteorol. 2011, 63, 459, DOI: 10.1111/j.1600-0889.2011.00546.x
Google Scholar
There is no corresponding record for this reference.
7
Kandler, K.; Lieke, K.; Benker, N.; Emmel, C.; Küpper, M.; Müller-Ebert, D.; Ebert, M.; Scheuvens, D.; Schladitz, A.; Schütz, L.; Weinbruch, S. Electron microscopy of particles collected at Praia, Cape Verde, during the Saharan Mineral Dust Experiment: particle chemistry, shape, mixing state and complex refractive index. Tellus B: Chem. Phys. Meteorol. 2011, 63, 475, DOI: 10.1111/j.1600-0889.2011.00550.x
Google Scholar
There is no corresponding record for this reference.
8
Lieke, K.; Kandler, K.; Scheuvens, D.; Emmel, C.; von Glahn, C.; Petzold, A.; Weinzierl, B.; Veira, A.; Ebert, M.; Weinbruch, S.; Schütz, L. Particle chemical properties in the vertical column based on aircraft observations in the vicinity of Cape Verde Islands. Tellus B: Chem. Phys. Meteorol. 2011, 63, 497, DOI: 10.1111/j.1600-0889.2011.00553.x
Google Scholar
There is no corresponding record for this reference.
9
Wendisch, M.; Pöschl, U.; Andreae, M. O.; Machado, L. A. T.; Albrecht, R.; Schlager, H.; Rosenfeld, D.; Martin, S. T.; Abdelmonem, A.; Afchine, A.; Araùjo, A. C.; Artaxo, P.; Aufmhoff, H.; Barbosa, H. M. J.; Borrmann, S.; Braga, R.; Buchholz, B.; Cecchini, M. A.; Costa, A.; Curtius, J.; Dollner, M.; Dorf, M.; Dreiling, V.; Ebert, V.; Ehrlich, A.; Ewald, F.; Fisch, G.; Fix, A.; Frank, F.; Fütterer, D.; Heckl, C.; Heidelberg, F.; Hüneke, T.; Jäkel, E.; Järvinen, E.; Jurkat, T.; Kanter, S.; Kästner, U.; Kenntner, M.; Kesselmeier, J.; Klimach, T.; Knecht, M.; Kohl, R.; Kölling, T.; Krämer, M.; Krüger, M.; Krisna, T. C.; Lavric, J. V.; Longo, K.; Mahnke, C.; Manzi, A. O.; Mayer, B.; Mertes, S.; Minikin, A.; Molleker, S.; Münch, S.; Nillius, B.; Pfeilsticker, K.; Pöhlker, C.; Roiger, A.; Rose, D.; Rosenow, D.; Sauer, D.; Schnaiter, M.; Schneider, J.; Schulz, C.; de Souza, R. A. F.; Spanu, A.; Stock, P.; Vila, D.; Voigt, C.; Walser, A.; Walter, D.; Weigel, R.; Weinzierl, B.; Werner, F.; Yamasoe, M. A.; Ziereis, H.; Zinner, T.; Zöger, M. ACRIDICON–CHUVA Campaign: Studying Tropical Deep Convective Clouds and Precipitation over Amazonia Using the New German Research Aircraft HALO. Bull. Am. Meteorol. Soc. 2016, 97, 1885– 1908, DOI: 10.1175/BAMS-D-14-00255.1
Google Scholar
There is no corresponding record for this reference.
10
Höpfner, M.; Ungermann, J.; Borrmann, S.; Wagner, R.; Spang, R.; Riese, M.; Stiller, G.; Appel, O.; Batenburg, A. M.; Bucci, S.; Cairo, F.; Dragoneas, A.; Friedl-Vallon, F.; Hünig, A.; Johansson, S.; Krasauskas, L.; Legras, B.; Leisner, T.; Mahnke, C.; Möhler, O.; Molleker, S.; Müller, R.; Neubert, T.; Orphal, J.; Preusse, P.; Rex, M.; Saathoff, H.; Stroh, F.; Weigel, R.; Wohltmann, I. Ammonium nitrate particles formed in upper troposphere from ground ammonia sources during Asian monsoons. Nat. Geosci. 2019, 12, 608– 612, DOI: 10.1038/s41561-019-0385-8
Google Scholar
There is no corresponding record for this reference.
11
Gonzalez, M. E.; Corral, A. F.; Crosbie, E.; Dadashazar, H.; Diskin, G. S.; Edwards, E.-L.; Kirschler, S.; Moore, R. H.; Robinson, C. E.; Schlosser, J. S.; Shook, M.; Stahl, C.; Thornhill, K. L.; Voigt, C.; Winstead, E.; Ziemba, L. D.; Sorooshian, A. Relationships between supermicrometer particle concentrations and cloud water sea salt and dust concentrations: analysis of MONARC and ACTIVATE data. Environ. Sci.: Atmos. 2022, 2, 738– 752, DOI: 10.1039/D2EA00049K
Google Scholar
There is no corresponding record for this reference.
12
Shupe, M. D.; Rex, M.; Blomquist, B.; Persson, P. O. G.; Schmale, J.; Uttal, T.; Althausen, D.; Angot, H.; Archer, S.; Bariteau, L.; Beck, I.; Bilberry, J.; Bucci, S.; Buck, C.; Boyer, M.; Brasseur, Z.; Brooks, I. M.; Calmer, R.; Cassano, J.; Castro, V.; Chu, D.; Costa, D.; Cox, C. J.; Creamean, J.; Crewell, S.; Dahlke, S.; Damm, E.; de Boer, G.; Deckelmann, H.; Dethloff, K.; Dütsch, M.; Ebell, K.; Ehrlich, A.; Ellis, J.; Engelmann, R.; Fong, A. A.; Frey, M. M.; Gallagher, M. R.; Ganzeveld, L.; Gradinger, R.; Graeser, J.; Greenamyer, V.; Griesche, H.; Griffiths, S.; Hamilton, J.; Heinemann, G.; Helmig, D.; Herber, A.; Heuzé, C.; Hofer, J.; Houchens, T.; Howard, D.; Inoue, J.; Jacobi, H.-W.; Jaiser, R.; Jokinen, T.; Jourdan, O.; Jozef, G.; King, W.; Kirchgaessner, A.; Klingebiel, M.; Krassovski, M.; Krumpen, T.; Lampert, A.; Landing, W.; Laurila, T.; Lawrence, D.; Lonardi, M.; Loose, B.; Lüpkes, C.; Maahn, M.; Macke, A.; Maslowski, W.; Marsay, C.; Maturilli, M.; Mech, M.; Morris, S.; Moser, M.; Nicolaus, M.; Ortega, P.; Osborn, J.; Pätzold, F.; Perovich, D. K.; Petäjä, T.; Pilz, C.; Pirazzini, R.; Posman, K.; Powers, H.; Pratt, K. A.; Preußer, A.; Quéléver, L.; Radenz, M.; Rabe, B.; Rinke, A.; Sachs, T.; Schulz, A.; Siebert, H.; Silva, T.; Solomon, A.; Sommerfeld, A.; Spreen, G.; Stephens, M.; Stohl, A.; Svensson, G.; Uin, J.; Viegas, J.; Voigt, C.; von der Gathen, P.; Wehner, B.; Welker, J. M.; Wendisch, M.; Werner, M.; Xie, Z.; Yue, F. Overview of the MOSAiC expedition: Atmosphere. Elem. Sci. Anth. 2022, 10, 00060 DOI: 10.1525/elementa.2021.00060
Google Scholar
There is no corresponding record for this reference.
13
Finlayson-Pitts, B. J. Reactions at surfaces in the atmosphere: integration of experiments and theory as necessary (but not necessarily sufficient) for predicting the physical chemistry of aerosols. Phys. Chem. Chem. Phys. 2009, 11, 7760– 7779, DOI: 10.1039/b906540g
Google Scholar
There is no corresponding record for this reference.
14
Finlayson-Pitts, B. J.; Hemminger, J. C. Physical Chemistry of Airborne Sea Salt Particles and Their Components. J. Phys. Chem. A 2000, 104, 11463– 11477, DOI: 10.1021/jp002968n
Google Scholar
There is no corresponding record for this reference.
15
Nozière, B.; Kalberer, M.; Claeys, M.; Allan, J.; D’Anna, B.; Decesari, S.; Finessi, E.; Glasius, M.; Grgić, I.; Hamilton, J. F.; Hoffmann, T.; Iinuma, Y.; Jaoui, M.; Kahnt, A.; Kampf, C. J.; Kourtchev, I.; Maenhaut, W.; Marsden, N.; Saarikoski, S.; Schnelle-Kreis, J.; Surratt, J. D.; Szidat, S.; Szmigielski, R.; Wisthaler, A. The molecular identification of organic compounds in the atmosphere: state of the art and challenges. Chem. Rev. 2015, 115, 3919– 3983, DOI: 10.1021/cr5003485
Google Scholar
There is no corresponding record for this reference.
16
Tabazadeh, A. Organic aggregate formation in aerosols and its impact on the physicochemical properties of atmospheric particles. Atmos. Environ. 2005, 39, 5472– 5480, DOI: 10.1016/j.atmosenv.2005.05.045
Google Scholar
There is no corresponding record for this reference.
17
Andreae, M. O.; Crutzen, P. J. Atmospheric Aerosols: Biogeochemical Sources and Role in Atmospheric Chemistry. Science 1997, 276, 1052– 1058, DOI: 10.1126/science.276.5315.1052
Google Scholar
There is no corresponding record for this reference.
18
Ren, Z. H.; Huang, J.; Luo, Y.; Zheng, Y. C.; Mei, P.; Lai, L.; Chang, Y. L. Micellization behavior of binary mixtures of amino sulfonate amphoteric surfactant with different octylphenol polyoxyethylene ethers in aqueous salt solution: Both cationic and hydrophilic effects. J. Ind. Eng. Chem. 2016, 36, 263– 270, DOI: 10.1016/j.jiec.2016.02.009
Google Scholar
There is no corresponding record for this reference.
19
Calderón, S. M.; Prisle, N. L. Composition dependent density of ternary aqueous solutions of ionic surfactants and salts. J. Atmos. Chem. 2021, 78, 99– 123, DOI: 10.1007/s10874-020-09411-8
Google Scholar
There is no corresponding record for this reference.
20
Qazi, M. J.; Schlegel, S. J.; Backus, E. H. G.; Bonn, M.; Bonn, D.; Shahidzadeh, N. Dynamic Surface Tension of Surfactants in the Presence of High Salt Concentrations. Langmuir 2020, 36, 7956– 7964, DOI: 10.1021/acs.langmuir.0c01211
Google Scholar
There is no corresponding record for this reference.
21
Finlayson-Pitts, B. J. Chlorine atoms as a potential tropospheric oxidant in the marine boundary layer. Res. Chem. Intermed. 1993, 19, 235– 249, DOI: 10.1163/156856793X00091
Google Scholar
There is no corresponding record for this reference.
22
Knipping, E. M.; Lakin, M. J.; Foster, K. L.; Jungwirth, P.; Tobias, D. J.; Gerber, R. B.; Dabdub, D.; Finlayson-Pitts, B. J. Experiments and Simulations of Ion-Enhanced Interfacial Chemistry on Aqueous NaCl Aerosols. Science 2000, 288, 301– 306, DOI: 10.1126/science.288.5464.301
Google Scholar
There is no corresponding record for this reference.
23
Seinfeld, J. H.; Bretherton, C.; Carslaw, K. S.; Coe, H.; DeMott, P. J.; Dunlea, E. J.; Feingold, G.; Ghan, S.; Guenther, A. B.; Kahn, R.; Kraucunas, I.; Kreidenweis, S. M.; Molina, M. J.; Nenes, A.; Penner, J. E.; Prather, K. A.; Ramanathan, V.; Ramaswamy, V.; Rasch, P. J.; Ravishankara, A. R.; Rosenfeld, D.; Stephens, G.; Wood, R. Improving our fundamental understanding of the role of aerosol-cloud interactions in the climate system. Proc. Natl. Acad. Sci. U.S.A. 2016, 113, 5781– 5790, DOI: 10.1073/pnas.1514043113
Google Scholar
There is no corresponding record for this reference.
24
Jungwirth, P.; Tobias, D. J. Molecular Structure of Salt Solutions: A New View of the Interface with Implications for Heterogeneous Atmospheric Chemistry. J. Phys. Chem. B 2001, 105, 10468– 10472, DOI: 10.1021/jp012750g
Google Scholar
There is no corresponding record for this reference.
25
Kleinheins, J.; Marcolli, C.; Dutcher, C. S.; Shardt, N. A unified surface tension model for multi-component salt, organic, and surfactant solutions. Phys. Chem. Chem. Phys. 2024, 26, 17521– 17538, DOI: 10.1039/D4CP00678J
Google Scholar
There is no corresponding record for this reference.
26
Motomura, K. Thermodynamic studies on adsorption at interfaces. I. General formulation. J. Colloid Interface Sci. 1978, 64, 348– 355, DOI: 10.1016/0021-9797(78)90371-5
Google Scholar
There is no corresponding record for this reference.
27
Motomura, K.; Matubayasi, N.; Aratono, M.; Matuura, R. Thermodynamic studies on adsorption at interfaces. II. One surface-active component system: Tetradecanol at hexane/water interface. J. Colloid Interface Sci. 1978, 64, 356– 361, DOI: 10.1016/0021-9797(78)90372-7
Google Scholar
There is no corresponding record for this reference.
28
Motomura, K.; Aratono, M.; Matubayasi, N.; Matuura, R. Thermodynamic studies on adsorption at interfaces. J. Colloid Interface Sci. 1978, 67, 247– 254, DOI: 10.1016/0021-9797(78)90009-7
Google Scholar
There is no corresponding record for this reference.
29
Motomura, K.; Iwanaga, S.-I.; Hayami, Y.; Uryu, S.; Matuura, R. Thermodynamic studies on adsorption at interfaces. J. Colloid Interface Sci. 1981, 80, 32– 38, DOI: 10.1016/0021-9797(81)90156-9
Google Scholar
There is no corresponding record for this reference.
30
Matubayasi, N.; Matsuo, H.; Yamamoto, K.; Yamaguchi, S.; Matuzawa, A. Thermodynamic Quantities of Surface Formation of Aqueous Electrolyte Solutions. J. Colloid Interface Sci. 1999, 209, 398– 402, DOI: 10.1006/jcis.1998.5928
Google Scholar
There is no corresponding record for this reference.
31
Matubayasi, N.; Yamamoto, K.; Yamaguchi, S.; Matsuo, H.; Ikeda, N. Thermodynamic Quantities of Surface Formation of Aqueous Electrolyte Solutions. J. Colloid Interface Sci. 1999, 214, 101– 105, DOI: 10.1006/jcis.1999.6172
Google Scholar
There is no corresponding record for this reference.
32
Matubayasi, N.; Tsunetomo, K.; Sato, I.; Akizuki, R.; Morishita, T.; Matuzawa, A.; Natsukari, Y. Thermodynamic Quantities of Surface Formation of Aqueous Electrolyte Solutions - IV. Sodium Halides, Anion Mixtures, and Sea Water. J. Colloid Interface Sci. 2001, 243, 444– 456, DOI: 10.1006/jcis.2001.7890
Google Scholar
There is no corresponding record for this reference.
33
Everett, D. H. Manual of Symbols and Terminology for Physicochemical Quantities and Units, Appendix II: Definitions, Terminology and Symbols in Colloid and Surface Chemistry. Pure Appl. Chem. 1972, 31, 577– 638, DOI: 10.1351/pac197231040577
Google Scholar
There is no corresponding record for this reference.
34
Matubayasi, N.; Yamaguchi, S.; Yamamoto, K.; Matsuo, H. Thermodynamic Quantities of Surface Formation of Aqueous Electrolyte Solutions. J. Colloid Interface Sci. 1999, 209, 403– 407, DOI: 10.1006/jcis.1998.5929
Google Scholar
There is no corresponding record for this reference.
35
Johansson, K.; Eriksson, J. C. γ and dγ/dT measurements on aqueous solutions of 1,1-electrolytes. J. Colloid Interface Sci. 1974, 49, 469– 480, DOI: 10.1016/0021-9797(74)90393-2
Google Scholar
There is no corresponding record for this reference.
36
Ozdemir, O.; Karakashev, S. I.; Nguyen, A. V.; Miller, J. D. Adsorption and surface tension analysis of concentrated alkali halide brine solutions. Miner. Eng. 2009, 22, 263– 271, DOI: 10.1016/j.mineng.2008.08.001
Google Scholar
There is no corresponding record for this reference.
37
Aveyard, R.; Saleem, S. M. Interfacial tensions at alkane-aqueous electrolyte interfaces. J. Chem. Soc., Faraday Trans. 1 1976, 72, 1609, DOI: 10.1039/f19767201609
Google Scholar
There is no corresponding record for this reference.
38
Henry, C. L.; Dalton, C. N.; Scruton, L.; Craig, V. S. J. Ion-Specific Coalescence of Bubbles in Mixed Electrolyte Solutions. J. Phys. Chem. C 2007, 111, 1015– 1023, DOI: 10.1021/jp066400b
Google Scholar
There is no corresponding record for this reference.
39
Weissenborn, P. K.; Pugh, R. J. Surface Tension and Bubble Coalescence Phenomena of Aqueous Solutions of Electrolytes. Langmuir 1995, 11, 1422– 1426, DOI: 10.1021/la00005a002
Google Scholar
There is no corresponding record for this reference.
40
Weissenborn, P. K.; Pugh, R. J. Surface Tension of Aqueous Solutions of Electrolytes: Relationship with Ion Hydration, Oxygen Solubility, and Bubble Coalescence. J. Colloid Interface Sci. 1996, 184, 550– 563, DOI: 10.1006/jcis.1996.0651
Google Scholar
There is no corresponding record for this reference.
41
Shah, A.-H. A.; Ali, K.; Bilal, S. Surface tension, surface excess concentration, enthalpy and entropy of surface formation of aqueous salt solutions. Colloids Surf. A Physicochem. Eng. Asp. 2013, 417, 183– 190, DOI: 10.1016/j.colsurfa.2012.10.054
Google Scholar
There is no corresponding record for this reference.
42
Horibe, A.; Fukusako, S.; Yamada, M. Surface tension of low-temperature aqueous solutions. Int. J. Thermophys. 1996, 17, 483– 493, DOI: 10.1007/BF01443405
Google Scholar
There is no corresponding record for this reference.
43
Bzdek, B. R.; Reid, J. P.; Malila, J.; Prisle, N. L. The surface tension of surfactant-containing, finite volume droplets. Proc. Natl. Acad. Sci. U.S.A. 2020, 117, 8335– 8343, DOI: 10.1073/pnas.1915660117
Google Scholar
There is no corresponding record for this reference.
44
Apelblat, A.; Manzurola, E. Volumetric properties of aqueous solutions of lithium chloride at temperatures from 278.15 K to 338.15 K and molalities (0.1, 0.5, and 1.0). J. Chem. Thermodyn. 2001, 33, 1133– 1155, DOI: 10.1006/jcht.2001.0826
Google Scholar
There is no corresponding record for this reference.
45
Isono, T. Density, viscosity, and electrolytic conductivity of concentrated aqueous electrolyte solutions at several temperatures. Alkaline-earth chlorides, lanthanum chloride, sodium chloride, sodium nitrate, sodium bromide, potassium nitrate, potassium bromide, and cadmium nitrate. J. Chem. Eng. Data 1984, 29, 45– 52, DOI: 10.1021/je00035a016
Google Scholar
There is no corresponding record for this reference.
46
Apelblat, A.; Manzurola, E. Volumetric properties of water, and solutions of sodium chloride and potassium chloride at temperatures from T = 277.15 K to T = 343.15 K at molalities of (0.1, 0.5, and 1.0)mol·kg–1. J. Chem. Thermodyn. 1999, 31, 869– 893, DOI: 10.1006/jcht.1999.0487
Google Scholar
There is no corresponding record for this reference.
47
Hoffert, U.; André, L.; Blöcher, G.; Guignot, S.; Lassin, A.; Milsch, H.; Sass, I. Density of pure and mixed NaCl and CaCl₂ aqueous solutions at 293 K to 353 K and 0.1 MPa: an integrated comparison of analytical and numerical data. Geotherm. Energy 2024, 12, 39, DOI: 10.1186/s40517-024-00318-1
Google Scholar
There is no corresponding record for this reference.
48
Rogers, P. S. Z.; Pitzer, K. S. Volumetric Properties of Aqueous Sodium Chloride Solutions. J. Phys. Chem. Ref. Data 1982, 11, 15– 81, DOI: 10.1063/1.555660
Google Scholar
There is no corresponding record for this reference.
49
Jarvis, N. L.; Scheiman, M. A. Surface potentials of aqueous electrolyte solutions. J. Phys. Chem. 1968, 72, 74– 78, DOI: 10.1021/j100847a014
Google Scholar
There is no corresponding record for this reference.
50
Jones, G.; Ray, W. A. The Surface Tension of Solutions. J. Am. Chem. Soc. 1935, 57, 957– 958, DOI: 10.1021/ja01308a506
Google Scholar
There is no corresponding record for this reference.
51
Jones, G.; Ray, W. A. The Surface Tension of Solutions of Electrolytes as a Function of the Concentration. III. Sodium Chloride. J. Am. Chem. Soc. 1941, 63, 3262– 3263, DOI: 10.1021/ja01857a007
Google Scholar
There is no corresponding record for this reference.
52
Jones, G.; Ray, W. A. The Surface Tension of Solutions of Electrolytes as a Function of the Concentration II *. J. Am. Chem. Soc. 1941, 63, 288– 294, DOI: 10.1021/ja01846a070
Google Scholar
There is no corresponding record for this reference.
53
Uematsu, Y.; Bonthuis, D. J.; Netz, R. R. Charged Surface-Active Impurities at Nanomolar Concentration Induce Jones-Ray Effect. J. Phys. Chem. Lett. 2018, 9, 189– 193, DOI: 10.1021/acs.jpclett.7b02960
Google Scholar
There is no corresponding record for this reference.
54
Okur, H. I.; Chen, Y.; Wilkins, D. M.; Roke, S. The Jones-Ray effect reinterpreted: Surface tension minima of low ionic strength electrolyte solutions are caused by electric field induced water-water correlations. Chem. Phys. Lett. 2017, 684, 433– 442, DOI: 10.1016/j.cplett.2017.06.018
Google Scholar
There is no corresponding record for this reference.
55
Okur, H. I.; Drexler, C. I.; Tyrode, E.; Cremer, P. S.; Roke, S. The Jones-Ray Effect Is Not Caused by Surface-Active Impurities. J. Phys. Chem. Lett. 2018, 9, 6739– 6743, DOI: 10.1021/acs.jpclett.8b02957
Google Scholar
There is no corresponding record for this reference.
56
Pegram, L. M.; Record, M. T. Hofmeister salt effects on surface tension arise from partitioning of anions and cations between bulk water and the air-water interface. J. Phys. Chem. B 2007, 111, 5411– 5417, DOI: 10.1021/jp070245z
Google Scholar
There is no corresponding record for this reference.
57
dos Santos, D. J. V. A.; Müller-Plathe, F.; Weiss, V. C. Consistency of Ion Adsorption and Excess Surface Tension in Molecular Dynamics Simulations of Aqueous Salt Solutions. J. Phys. Chem. C 2008, 112, 19431– 19442, DOI: 10.1021/jp804811u
Google Scholar
There is no corresponding record for this reference.
58
Boström, M.; Kunz, W.; Ninham, B. W. Hofmeister effects in surface tension of aqueous electrolyte solution. Langmuir 2005, 21, 2619– 2623, DOI: 10.1021/la047437v
Google Scholar
There is no corresponding record for this reference.
59
D’Auria, R.; Tobias, D. J. Relation between surface tension and ion adsorption at the air-water interface: a molecular dynamics simulation study. J. Phys. Chem. A 2009, 113, 7286– 7293, DOI: 10.1021/jp810488p
Google Scholar
There is no corresponding record for this reference.
60
Sun, L.; Li, X.; Hede, T.; Tu, Y.; Leck, C.; Ågren, H. Molecular dynamics simulations of the surface tension and structure of salt solutions and clusters. J. Phys. Chem. B 2012, 116, 3198– 3204, DOI: 10.1021/jp209178s
Google Scholar
There is no corresponding record for this reference.
61
Smith, R. Ion clustering in aqueous salt solutions near the liquid/vapor interface. Condens. Matter Phys. 2016, 19, 23002, DOI: 10.5488/CMP.19.23002
Google Scholar
There is no corresponding record for this reference.
62
Ghosal, S.; Hemminger, J. C.; Bluhm, H.; Mun, B. S.; Hebenstreit, E. L. D.; Ketteler, G.; Ogletree, D. F.; Requejo, F. G.; Salmeron, M. Electron Spectroscopy of Aqueous Solution Interfaces Reveals Surface Enhancement of Halides. Science 2005, 307, 563– 566, DOI: 10.1126/science.1106525
Google Scholar
There is no corresponding record for this reference.
63
Krisch, M. J.; D’Auria, R.; Brown, M. A.; Tobias, D. J.; Hemminger, C.; Ammann, M.; Starr, D. E.; Bluhm, H. The Effect of an Organic Surfactant on the Liquid–Vapor Interface of an Electrolyte Solution. J. Phys. Chem. C 2007, 111, 13497– 13509, DOI: 10.1021/jp073078b
Google Scholar
There is no corresponding record for this reference.
64
Onorato, R. M.; Otten, D. E.; Saykally, R. J. Measurement of Bromide Ion Affinities for the Air/Water and Dodecanol/Water Interfaces at Molar Concentrations by UV Second Harmonic Generation Spectroscopy. J. Phys. Chem. C 2010, 114, 13746– 13751, DOI: 10.1021/jp103454r
Google Scholar
There is no corresponding record for this reference.
65
Matubayasi, N.; Sugiyama, S.; Kanzaki, M.; Matuzawa, A. Thermodynamic Studies of the Adsorbed Films and Micelles of Sodium Taurodeoxycholate. J. Colloid Interface Sci. 1997, 196, 123– 127, DOI: 10.1006/jcis.1997.5213
Google Scholar
There is no corresponding record for this reference.

Cited By

Click to copy section linkSection link copied!

This article has not yet been cited by other publications.

Get e-Alerts

Journal of Chemical & Engineering Data

Cite this: J. Chem. Eng. Data 2025, 70, 12, 4901–4914

Click to copy citationCitation copied!

https://doi.org/10.1021/acs.jced.5c00470

Published November 25, 2025

CC-BY 4.0 .

Article Views

Altmetric

Citations

Learn about these metrics

Article Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.

Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.

The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated.

Abstract
High Resolution Image
Download MS PowerPoint Slide
Figure 1
Figure 1. Density ρ of aqueous salt solutions of NaCl as a function of molality m at a temperature T = 293.15 K and at a pressure p = 100,000 Pa for: solid line and × own data (cf. Table 2) in comparison with data from literature: blue ● Hoffert et al., (47) red ▲ Rogers and Pitzer, (48) and gray ◆ Shah et al. (41) Note that the reference data from Rogers and Pitzer are given as specific volumes and were converted into density for comparison.
High Resolution Image
Download MS PowerPoint Slide
Figure 2
Figure 2. Surface tension γ of aqueous salt solutions of NaCl as a function of temperature T at a pressure p = 100,000 Pa for own data at: ■ 2.994 mol·kg^–1, blue ● 1.997 mol·kg^–1, gray ▲ 0.984 mol·kg^–1 (cf. Table 3) and data from literature (42) at: □ 3.020 mol·kg^–1, blue ○ 1.901 mol·kg^–1, gray △ 0.901 mol·kg^–1. The concentrations of the reference data are given in mass fractions and were converted into molality for comparison (cf. Chapter S1 in the SI).
High Resolution Image
Download MS PowerPoint Slide
Figure 3
Figure 3. Surface tension γ of aqueous salt solutions of NaBr as a function of temperature T at a pressure p = 100,000 Pa: ■ 0.116 mol·kg^–1, gray ● 0.464 mol·kg^–1, ▲ 0.988 mol·kg^–1, gray ▼ 2.994 mol·kg^–1, ◆ 3.971 mol·kg^–1, gray ◀ 5.046 mol·kg^–1 (cf. Table 3).
High Resolution Image
Download MS PowerPoint Slide
Figure 4
Figure 4. Surface tension γ of aqueous salt solutions of NaBr as a function of molality m at a pressure p = 100,000 Pa: Solid and dotted lines result from linear fit at ■ 293.15 K, gray ● 288.15 K, ▲ 283.15 K, gray ▼ 278.15 K, ◆ 273.15 K, gray ◀ 271.15 K, ▶ 268.15 K, gray × 263.15 K (cf. Table 3).
High Resolution Image
Download MS PowerPoint Slide
Figure 5
Figure 5. Linear fit results of the excess surface tension Δγ of aqueous salt solutions as a function of molality m at a temperature T = 293.15 K and a pressure p = 100,000 Pa of green ─ NaCl, orange ─ NaBr, red ─ NaI, sky blue ─ LiCl, gray ─ KCl, purple ─ MgCl₂, and blue ─ Na₂SO₄. (cf. Figures S16 and S17). See Chapter 10 in the SI for more information on fitting the experimental data.
High Resolution Image
Download MS PowerPoint Slide
Figure 6
Figure 6. Surface excess entropy $Δ s^{σ}$ of aqueous salt solutions as a function of molality m at a pressure p = 100,000 Pa of: ■ NaCl, ○ NaBr, gray ▲ NaI (cf. Table 6).
High Resolution Image
Download MS PowerPoint Slide
Figure 7
Figure 7. Surface excess entropy Δs^σ of aqueous salt solutions as a function of molality m at a pressure p = 100,000 Pa of: ■ NaCl (again for comparison), ○ LiCl, gray ▲ KCl (cf. Table 6).
High Resolution Image
Download MS PowerPoint Slide
Figure 8
Figure 8. Thermodynamic quantities of aqueous salt solutions of NaBr as a function of molality m and their linear fits at a pressure p = 100,000 Pa: ▲ surface excess energy Δu^σ(cf. Table 6), gray ■ surface excess Helmholtz energy Δa^σ at T = 293.15 K (cf. Table 3), ○ surface excess enthalpy Δh^σ at T = 293.15 K (cf. Table 6). The error bars correspond to the uncertainties of Δu^σ and Δh^σ given in Table 6. The uncertainties of Δa^σ are too small to depict, but they are equal to those of the surface tension given in Table S6 in SI.
High Resolution Image
Download MS PowerPoint Slide
References
This article references 65 other publications.
1. 1
  Lelieveld, J.; Crutzen, P. J.; Ramanathan, V.; Andreae, M. O.; Brenninkmeijer, C. M.; Campos, T.; Cass, G. R.; Dickerson, R. R.; Fischer, H.; de Gouw, J. A.; Hansel, A.; Jefferson, A.; Kley, D.; de Laat, A. T.; Lal, S.; Lawrence, M. G.; Lobert, J. M.; Mayol-Bracero, O. L.; Mitra, A. P.; Novakov, T.; Oltmans, S. J.; Prather, K. A.; Reiner, T.; Rodhe, H.; Scheeren, H. A.; Sikka, D.; Williams, J. The Indian Ocean experiment: widespread air pollution from South and Southeast Asia. Science 2001, 291, 1031– 1036, DOI: 10.1126/science.1057103
  There is no corresponding record for this reference.
2. 2
  Ramanathan, V.; Crutzen, P. J.; Lelieveld, J.; Mitra, A. P.; Althausen, D.; Anderson, J.; Andreae, M. O.; Cantrell, W.; Cass, G. R.; Chung, C. E.; Clarke, A. D.; Coakley, J. A.; Collins, W. D.; Conant, W. C.; Dulac, F.; Heintzenberg, J.; Heymsfield, A. J.; Holben, B.; Howell, S.; Hudson, J.; Jayaraman, A.; Kiehl, J. T.; Krishnamurti, T. N.; Lubin, D.; McFarquhar, G.; Novakov, T.; Ogren, J. A.; Podgorny, I. A.; Prather, K.; Priestley, K.; Prospero, J. M.; Quinn, P. K.; Rajeev, K.; Rasch, P.; Rupert, S.; Sadourny, R.; Satheesh, S. K.; Shaw, G. E.; Sheridan, P.; Valero, F. P. J. Indian Ocean Experiment: An integrated analysis of the climate forcing and effects of the great Indo-Asian haze. J. Geophys. Res. 2001, 106, 28371– 28398, DOI: 10.1029/2001JD900133
  There is no corresponding record for this reference.
3. 3
  Brenninkmeijer, C. A. M.; Slemr, F.; Koeppel, C.; Scharffe, D. S.; Pupek, M.; Lelieveld, J.; Crutzen, P.; Zahn, A.; Sprung, D.; Fischer, H.; Hermann, M.; Reichelt, M.; Heintzenberg, J.; Schlager, H.; Ziereis, H.; Schumann, U.; Dix, B.; Platt, U.; Ebinghaus, R.; Martinsson, B.; Ciais, P.; Filippi, D.; Leuenberger, M.; Oram, D.; Penkett, S.; van Velthoven, P.; Waibel, A. Analyzing atmospheric trace gases and aerosols using passenger aircraft. EOS Trans. Am. Geophys. Union 2005, 86, 77– 83, DOI: 10.1029/2005EO080001
  There is no corresponding record for this reference.
4. 4
  Park, S. S.; Bae, M.-S.; Schauer, J. J.; Kim, Y. J.; Yong Cho, S.; Jai Kim, S. Molecular composition of PM2.5 organic aerosol measured at an urban site of Korea during the ACE-Asia campaign. Atmos. Environ. 2006, 40, 4182– 4198, DOI: 10.1016/j.atmosenv.2006.02.012
  There is no corresponding record for this reference.
5. 5
  Ansmann, A.; Petzold, A.; Kandler, K.; Tegen, I.; Wendisch, M.; Müller, D.; Weinzierl, B.; Müller, T.; Heintzenberg, J. Saharan Mineral Dust Experiments SAMUM–1 and SAMUM–2: what have we learned?. Tellus B: Chem. Phys. Meteorol. 2011, 63, 403, DOI: 10.1111/j.1600-0889.2011.00555.x
  There is no corresponding record for this reference.
6. 6
  Kandler, K.; Schütz, L.; Jäckel, S.; Lieke, K.; Emmel, C.; Müller-Ebert, D.; Ebert, M.; Scheuvens, D.; Schladitz, A.; Šegvié, B.; Wiedensohler, A.; Weinbruch, S. Ground-based off-line aerosol measurements at Praia, Cape Verde, during the Saharan Mineral Dust Experiment: microphysical properties and mineralogy. Tellus B: Chem. Phys. Meteorol. 2011, 63, 459, DOI: 10.1111/j.1600-0889.2011.00546.x
  There is no corresponding record for this reference.
7. 7
  Kandler, K.; Lieke, K.; Benker, N.; Emmel, C.; Küpper, M.; Müller-Ebert, D.; Ebert, M.; Scheuvens, D.; Schladitz, A.; Schütz, L.; Weinbruch, S. Electron microscopy of particles collected at Praia, Cape Verde, during the Saharan Mineral Dust Experiment: particle chemistry, shape, mixing state and complex refractive index. Tellus B: Chem. Phys. Meteorol. 2011, 63, 475, DOI: 10.1111/j.1600-0889.2011.00550.x
  There is no corresponding record for this reference.
8. 8
  Lieke, K.; Kandler, K.; Scheuvens, D.; Emmel, C.; von Glahn, C.; Petzold, A.; Weinzierl, B.; Veira, A.; Ebert, M.; Weinbruch, S.; Schütz, L. Particle chemical properties in the vertical column based on aircraft observations in the vicinity of Cape Verde Islands. Tellus B: Chem. Phys. Meteorol. 2011, 63, 497, DOI: 10.1111/j.1600-0889.2011.00553.x
  There is no corresponding record for this reference.
9. 9
  Wendisch, M.; Pöschl, U.; Andreae, M. O.; Machado, L. A. T.; Albrecht, R.; Schlager, H.; Rosenfeld, D.; Martin, S. T.; Abdelmonem, A.; Afchine, A.; Araùjo, A. C.; Artaxo, P.; Aufmhoff, H.; Barbosa, H. M. J.; Borrmann, S.; Braga, R.; Buchholz, B.; Cecchini, M. A.; Costa, A.; Curtius, J.; Dollner, M.; Dorf, M.; Dreiling, V.; Ebert, V.; Ehrlich, A.; Ewald, F.; Fisch, G.; Fix, A.; Frank, F.; Fütterer, D.; Heckl, C.; Heidelberg, F.; Hüneke, T.; Jäkel, E.; Järvinen, E.; Jurkat, T.; Kanter, S.; Kästner, U.; Kenntner, M.; Kesselmeier, J.; Klimach, T.; Knecht, M.; Kohl, R.; Kölling, T.; Krämer, M.; Krüger, M.; Krisna, T. C.; Lavric, J. V.; Longo, K.; Mahnke, C.; Manzi, A. O.; Mayer, B.; Mertes, S.; Minikin, A.; Molleker, S.; Münch, S.; Nillius, B.; Pfeilsticker, K.; Pöhlker, C.; Roiger, A.; Rose, D.; Rosenow, D.; Sauer, D.; Schnaiter, M.; Schneider, J.; Schulz, C.; de Souza, R. A. F.; Spanu, A.; Stock, P.; Vila, D.; Voigt, C.; Walser, A.; Walter, D.; Weigel, R.; Weinzierl, B.; Werner, F.; Yamasoe, M. A.; Ziereis, H.; Zinner, T.; Zöger, M. ACRIDICON–CHUVA Campaign: Studying Tropical Deep Convective Clouds and Precipitation over Amazonia Using the New German Research Aircraft HALO. Bull. Am. Meteorol. Soc. 2016, 97, 1885– 1908, DOI: 10.1175/BAMS-D-14-00255.1
  There is no corresponding record for this reference.
10. 10
  Höpfner, M.; Ungermann, J.; Borrmann, S.; Wagner, R.; Spang, R.; Riese, M.; Stiller, G.; Appel, O.; Batenburg, A. M.; Bucci, S.; Cairo, F.; Dragoneas, A.; Friedl-Vallon, F.; Hünig, A.; Johansson, S.; Krasauskas, L.; Legras, B.; Leisner, T.; Mahnke, C.; Möhler, O.; Molleker, S.; Müller, R.; Neubert, T.; Orphal, J.; Preusse, P.; Rex, M.; Saathoff, H.; Stroh, F.; Weigel, R.; Wohltmann, I. Ammonium nitrate particles formed in upper troposphere from ground ammonia sources during Asian monsoons. Nat. Geosci. 2019, 12, 608– 612, DOI: 10.1038/s41561-019-0385-8
  There is no corresponding record for this reference.
11. 11
  Gonzalez, M. E.; Corral, A. F.; Crosbie, E.; Dadashazar, H.; Diskin, G. S.; Edwards, E.-L.; Kirschler, S.; Moore, R. H.; Robinson, C. E.; Schlosser, J. S.; Shook, M.; Stahl, C.; Thornhill, K. L.; Voigt, C.; Winstead, E.; Ziemba, L. D.; Sorooshian, A. Relationships between supermicrometer particle concentrations and cloud water sea salt and dust concentrations: analysis of MONARC and ACTIVATE data. Environ. Sci.: Atmos. 2022, 2, 738– 752, DOI: 10.1039/D2EA00049K
  There is no corresponding record for this reference.
12. 12
  Shupe, M. D.; Rex, M.; Blomquist, B.; Persson, P. O. G.; Schmale, J.; Uttal, T.; Althausen, D.; Angot, H.; Archer, S.; Bariteau, L.; Beck, I.; Bilberry, J.; Bucci, S.; Buck, C.; Boyer, M.; Brasseur, Z.; Brooks, I. M.; Calmer, R.; Cassano, J.; Castro, V.; Chu, D.; Costa, D.; Cox, C. J.; Creamean, J.; Crewell, S.; Dahlke, S.; Damm, E.; de Boer, G.; Deckelmann, H.; Dethloff, K.; Dütsch, M.; Ebell, K.; Ehrlich, A.; Ellis, J.; Engelmann, R.; Fong, A. A.; Frey, M. M.; Gallagher, M. R.; Ganzeveld, L.; Gradinger, R.; Graeser, J.; Greenamyer, V.; Griesche, H.; Griffiths, S.; Hamilton, J.; Heinemann, G.; Helmig, D.; Herber, A.; Heuzé, C.; Hofer, J.; Houchens, T.; Howard, D.; Inoue, J.; Jacobi, H.-W.; Jaiser, R.; Jokinen, T.; Jourdan, O.; Jozef, G.; King, W.; Kirchgaessner, A.; Klingebiel, M.; Krassovski, M.; Krumpen, T.; Lampert, A.; Landing, W.; Laurila, T.; Lawrence, D.; Lonardi, M.; Loose, B.; Lüpkes, C.; Maahn, M.; Macke, A.; Maslowski, W.; Marsay, C.; Maturilli, M.; Mech, M.; Morris, S.; Moser, M.; Nicolaus, M.; Ortega, P.; Osborn, J.; Pätzold, F.; Perovich, D. K.; Petäjä, T.; Pilz, C.; Pirazzini, R.; Posman, K.; Powers, H.; Pratt, K. A.; Preußer, A.; Quéléver, L.; Radenz, M.; Rabe, B.; Rinke, A.; Sachs, T.; Schulz, A.; Siebert, H.; Silva, T.; Solomon, A.; Sommerfeld, A.; Spreen, G.; Stephens, M.; Stohl, A.; Svensson, G.; Uin, J.; Viegas, J.; Voigt, C.; von der Gathen, P.; Wehner, B.; Welker, J. M.; Wendisch, M.; Werner, M.; Xie, Z.; Yue, F. Overview of the MOSAiC expedition: Atmosphere. Elem. Sci. Anth. 2022, 10, 00060 DOI: 10.1525/elementa.2021.00060
  There is no corresponding record for this reference.
13. 13
  Finlayson-Pitts, B. J. Reactions at surfaces in the atmosphere: integration of experiments and theory as necessary (but not necessarily sufficient) for predicting the physical chemistry of aerosols. Phys. Chem. Chem. Phys. 2009, 11, 7760– 7779, DOI: 10.1039/b906540g
  There is no corresponding record for this reference.
14. 14
  Finlayson-Pitts, B. J.; Hemminger, J. C. Physical Chemistry of Airborne Sea Salt Particles and Their Components. J. Phys. Chem. A 2000, 104, 11463– 11477, DOI: 10.1021/jp002968n
  There is no corresponding record for this reference.
15. 15
  Nozière, B.; Kalberer, M.; Claeys, M.; Allan, J.; D’Anna, B.; Decesari, S.; Finessi, E.; Glasius, M.; Grgić, I.; Hamilton, J. F.; Hoffmann, T.; Iinuma, Y.; Jaoui, M.; Kahnt, A.; Kampf, C. J.; Kourtchev, I.; Maenhaut, W.; Marsden, N.; Saarikoski, S.; Schnelle-Kreis, J.; Surratt, J. D.; Szidat, S.; Szmigielski, R.; Wisthaler, A. The molecular identification of organic compounds in the atmosphere: state of the art and challenges. Chem. Rev. 2015, 115, 3919– 3983, DOI: 10.1021/cr5003485
  There is no corresponding record for this reference.
16. 16
  Tabazadeh, A. Organic aggregate formation in aerosols and its impact on the physicochemical properties of atmospheric particles. Atmos. Environ. 2005, 39, 5472– 5480, DOI: 10.1016/j.atmosenv.2005.05.045
  There is no corresponding record for this reference.
17. 17
  Andreae, M. O.; Crutzen, P. J. Atmospheric Aerosols: Biogeochemical Sources and Role in Atmospheric Chemistry. Science 1997, 276, 1052– 1058, DOI: 10.1126/science.276.5315.1052
  There is no corresponding record for this reference.
18. 18
  Ren, Z. H.; Huang, J.; Luo, Y.; Zheng, Y. C.; Mei, P.; Lai, L.; Chang, Y. L. Micellization behavior of binary mixtures of amino sulfonate amphoteric surfactant with different octylphenol polyoxyethylene ethers in aqueous salt solution: Both cationic and hydrophilic effects. J. Ind. Eng. Chem. 2016, 36, 263– 270, DOI: 10.1016/j.jiec.2016.02.009
  There is no corresponding record for this reference.
19. 19
  Calderón, S. M.; Prisle, N. L. Composition dependent density of ternary aqueous solutions of ionic surfactants and salts. J. Atmos. Chem. 2021, 78, 99– 123, DOI: 10.1007/s10874-020-09411-8
  There is no corresponding record for this reference.
20. 20
  Qazi, M. J.; Schlegel, S. J.; Backus, E. H. G.; Bonn, M.; Bonn, D.; Shahidzadeh, N. Dynamic Surface Tension of Surfactants in the Presence of High Salt Concentrations. Langmuir 2020, 36, 7956– 7964, DOI: 10.1021/acs.langmuir.0c01211
  There is no corresponding record for this reference.
21. 21
  Finlayson-Pitts, B. J. Chlorine atoms as a potential tropospheric oxidant in the marine boundary layer. Res. Chem. Intermed. 1993, 19, 235– 249, DOI: 10.1163/156856793X00091
  There is no corresponding record for this reference.
22. 22
  Knipping, E. M.; Lakin, M. J.; Foster, K. L.; Jungwirth, P.; Tobias, D. J.; Gerber, R. B.; Dabdub, D.; Finlayson-Pitts, B. J. Experiments and Simulations of Ion-Enhanced Interfacial Chemistry on Aqueous NaCl Aerosols. Science 2000, 288, 301– 306, DOI: 10.1126/science.288.5464.301
  There is no corresponding record for this reference.
23. 23
  Seinfeld, J. H.; Bretherton, C.; Carslaw, K. S.; Coe, H.; DeMott, P. J.; Dunlea, E. J.; Feingold, G.; Ghan, S.; Guenther, A. B.; Kahn, R.; Kraucunas, I.; Kreidenweis, S. M.; Molina, M. J.; Nenes, A.; Penner, J. E.; Prather, K. A.; Ramanathan, V.; Ramaswamy, V.; Rasch, P. J.; Ravishankara, A. R.; Rosenfeld, D.; Stephens, G.; Wood, R. Improving our fundamental understanding of the role of aerosol-cloud interactions in the climate system. Proc. Natl. Acad. Sci. U.S.A. 2016, 113, 5781– 5790, DOI: 10.1073/pnas.1514043113
  There is no corresponding record for this reference.
24. 24
  Jungwirth, P.; Tobias, D. J. Molecular Structure of Salt Solutions: A New View of the Interface with Implications for Heterogeneous Atmospheric Chemistry. J. Phys. Chem. B 2001, 105, 10468– 10472, DOI: 10.1021/jp012750g
  There is no corresponding record for this reference.
25. 25
  Kleinheins, J.; Marcolli, C.; Dutcher, C. S.; Shardt, N. A unified surface tension model for multi-component salt, organic, and surfactant solutions. Phys. Chem. Chem. Phys. 2024, 26, 17521– 17538, DOI: 10.1039/D4CP00678J
  There is no corresponding record for this reference.
26. 26
  Motomura, K. Thermodynamic studies on adsorption at interfaces. I. General formulation. J. Colloid Interface Sci. 1978, 64, 348– 355, DOI: 10.1016/0021-9797(78)90371-5
  There is no corresponding record for this reference.
27. 27
  Motomura, K.; Matubayasi, N.; Aratono, M.; Matuura, R. Thermodynamic studies on adsorption at interfaces. II. One surface-active component system: Tetradecanol at hexane/water interface. J. Colloid Interface Sci. 1978, 64, 356– 361, DOI: 10.1016/0021-9797(78)90372-7
  There is no corresponding record for this reference.
28. 28
  Motomura, K.; Aratono, M.; Matubayasi, N.; Matuura, R. Thermodynamic studies on adsorption at interfaces. J. Colloid Interface Sci. 1978, 67, 247– 254, DOI: 10.1016/0021-9797(78)90009-7
  There is no corresponding record for this reference.
29. 29
  Motomura, K.; Iwanaga, S.-I.; Hayami, Y.; Uryu, S.; Matuura, R. Thermodynamic studies on adsorption at interfaces. J. Colloid Interface Sci. 1981, 80, 32– 38, DOI: 10.1016/0021-9797(81)90156-9
  There is no corresponding record for this reference.
30. 30
  Matubayasi, N.; Matsuo, H.; Yamamoto, K.; Yamaguchi, S.; Matuzawa, A. Thermodynamic Quantities of Surface Formation of Aqueous Electrolyte Solutions. J. Colloid Interface Sci. 1999, 209, 398– 402, DOI: 10.1006/jcis.1998.5928
  There is no corresponding record for this reference.
31. 31
  Matubayasi, N.; Yamamoto, K.; Yamaguchi, S.; Matsuo, H.; Ikeda, N. Thermodynamic Quantities of Surface Formation of Aqueous Electrolyte Solutions. J. Colloid Interface Sci. 1999, 214, 101– 105, DOI: 10.1006/jcis.1999.6172
  There is no corresponding record for this reference.
32. 32
  Matubayasi, N.; Tsunetomo, K.; Sato, I.; Akizuki, R.; Morishita, T.; Matuzawa, A.; Natsukari, Y. Thermodynamic Quantities of Surface Formation of Aqueous Electrolyte Solutions - IV. Sodium Halides, Anion Mixtures, and Sea Water. J. Colloid Interface Sci. 2001, 243, 444– 456, DOI: 10.1006/jcis.2001.7890
  There is no corresponding record for this reference.
33. 33
  Everett, D. H. Manual of Symbols and Terminology for Physicochemical Quantities and Units, Appendix II: Definitions, Terminology and Symbols in Colloid and Surface Chemistry. Pure Appl. Chem. 1972, 31, 577– 638, DOI: 10.1351/pac197231040577
  There is no corresponding record for this reference.
34. 34
  Matubayasi, N.; Yamaguchi, S.; Yamamoto, K.; Matsuo, H. Thermodynamic Quantities of Surface Formation of Aqueous Electrolyte Solutions. J. Colloid Interface Sci. 1999, 209, 403– 407, DOI: 10.1006/jcis.1998.5929
  There is no corresponding record for this reference.
35. 35
  Johansson, K.; Eriksson, J. C. γ and dγ/dT measurements on aqueous solutions of 1,1-electrolytes. J. Colloid Interface Sci. 1974, 49, 469– 480, DOI: 10.1016/0021-9797(74)90393-2
  There is no corresponding record for this reference.
36. 36
  Ozdemir, O.; Karakashev, S. I.; Nguyen, A. V.; Miller, J. D. Adsorption and surface tension analysis of concentrated alkali halide brine solutions. Miner. Eng. 2009, 22, 263– 271, DOI: 10.1016/j.mineng.2008.08.001
  There is no corresponding record for this reference.
37. 37
  Aveyard, R.; Saleem, S. M. Interfacial tensions at alkane-aqueous electrolyte interfaces. J. Chem. Soc., Faraday Trans. 1 1976, 72, 1609, DOI: 10.1039/f19767201609
  There is no corresponding record for this reference.
38. 38
  Henry, C. L.; Dalton, C. N.; Scruton, L.; Craig, V. S. J. Ion-Specific Coalescence of Bubbles in Mixed Electrolyte Solutions. J. Phys. Chem. C 2007, 111, 1015– 1023, DOI: 10.1021/jp066400b
  There is no corresponding record for this reference.
39. 39
  Weissenborn, P. K.; Pugh, R. J. Surface Tension and Bubble Coalescence Phenomena of Aqueous Solutions of Electrolytes. Langmuir 1995, 11, 1422– 1426, DOI: 10.1021/la00005a002
  There is no corresponding record for this reference.
40. 40
  Weissenborn, P. K.; Pugh, R. J. Surface Tension of Aqueous Solutions of Electrolytes: Relationship with Ion Hydration, Oxygen Solubility, and Bubble Coalescence. J. Colloid Interface Sci. 1996, 184, 550– 563, DOI: 10.1006/jcis.1996.0651
  There is no corresponding record for this reference.
41. 41
  Shah, A.-H. A.; Ali, K.; Bilal, S. Surface tension, surface excess concentration, enthalpy and entropy of surface formation of aqueous salt solutions. Colloids Surf. A Physicochem. Eng. Asp. 2013, 417, 183– 190, DOI: 10.1016/j.colsurfa.2012.10.054
  There is no corresponding record for this reference.
42. 42
  Horibe, A.; Fukusako, S.; Yamada, M. Surface tension of low-temperature aqueous solutions. Int. J. Thermophys. 1996, 17, 483– 493, DOI: 10.1007/BF01443405
  There is no corresponding record for this reference.
43. 43
  Bzdek, B. R.; Reid, J. P.; Malila, J.; Prisle, N. L. The surface tension of surfactant-containing, finite volume droplets. Proc. Natl. Acad. Sci. U.S.A. 2020, 117, 8335– 8343, DOI: 10.1073/pnas.1915660117
  There is no corresponding record for this reference.
44. 44
  Apelblat, A.; Manzurola, E. Volumetric properties of aqueous solutions of lithium chloride at temperatures from 278.15 K to 338.15 K and molalities (0.1, 0.5, and 1.0). J. Chem. Thermodyn. 2001, 33, 1133– 1155, DOI: 10.1006/jcht.2001.0826
  There is no corresponding record for this reference.
45. 45
  Isono, T. Density, viscosity, and electrolytic conductivity of concentrated aqueous electrolyte solutions at several temperatures. Alkaline-earth chlorides, lanthanum chloride, sodium chloride, sodium nitrate, sodium bromide, potassium nitrate, potassium bromide, and cadmium nitrate. J. Chem. Eng. Data 1984, 29, 45– 52, DOI: 10.1021/je00035a016
  There is no corresponding record for this reference.
46. 46
  Apelblat, A.; Manzurola, E. Volumetric properties of water, and solutions of sodium chloride and potassium chloride at temperatures from T = 277.15 K to T = 343.15 K at molalities of (0.1, 0.5, and 1.0)mol·kg–1. J. Chem. Thermodyn. 1999, 31, 869– 893, DOI: 10.1006/jcht.1999.0487
  There is no corresponding record for this reference.
47. 47
  Hoffert, U.; André, L.; Blöcher, G.; Guignot, S.; Lassin, A.; Milsch, H.; Sass, I. Density of pure and mixed NaCl and CaCl₂ aqueous solutions at 293 K to 353 K and 0.1 MPa: an integrated comparison of analytical and numerical data. Geotherm. Energy 2024, 12, 39, DOI: 10.1186/s40517-024-00318-1
  There is no corresponding record for this reference.
48. 48
  Rogers, P. S. Z.; Pitzer, K. S. Volumetric Properties of Aqueous Sodium Chloride Solutions. J. Phys. Chem. Ref. Data 1982, 11, 15– 81, DOI: 10.1063/1.555660
  There is no corresponding record for this reference.
49. 49
  Jarvis, N. L.; Scheiman, M. A. Surface potentials of aqueous electrolyte solutions. J. Phys. Chem. 1968, 72, 74– 78, DOI: 10.1021/j100847a014
  There is no corresponding record for this reference.
50. 50
  Jones, G.; Ray, W. A. The Surface Tension of Solutions. J. Am. Chem. Soc. 1935, 57, 957– 958, DOI: 10.1021/ja01308a506
  There is no corresponding record for this reference.
51. 51
  Jones, G.; Ray, W. A. The Surface Tension of Solutions of Electrolytes as a Function of the Concentration. III. Sodium Chloride. J. Am. Chem. Soc. 1941, 63, 3262– 3263, DOI: 10.1021/ja01857a007
  There is no corresponding record for this reference.
52. 52
  Jones, G.; Ray, W. A. The Surface Tension of Solutions of Electrolytes as a Function of the Concentration II *. J. Am. Chem. Soc. 1941, 63, 288– 294, DOI: 10.1021/ja01846a070
  There is no corresponding record for this reference.
53. 53
  Uematsu, Y.; Bonthuis, D. J.; Netz, R. R. Charged Surface-Active Impurities at Nanomolar Concentration Induce Jones-Ray Effect. J. Phys. Chem. Lett. 2018, 9, 189– 193, DOI: 10.1021/acs.jpclett.7b02960
  There is no corresponding record for this reference.
54. 54
  Okur, H. I.; Chen, Y.; Wilkins, D. M.; Roke, S. The Jones-Ray effect reinterpreted: Surface tension minima of low ionic strength electrolyte solutions are caused by electric field induced water-water correlations. Chem. Phys. Lett. 2017, 684, 433– 442, DOI: 10.1016/j.cplett.2017.06.018
  There is no corresponding record for this reference.
55. 55
  Okur, H. I.; Drexler, C. I.; Tyrode, E.; Cremer, P. S.; Roke, S. The Jones-Ray Effect Is Not Caused by Surface-Active Impurities. J. Phys. Chem. Lett. 2018, 9, 6739– 6743, DOI: 10.1021/acs.jpclett.8b02957
  There is no corresponding record for this reference.
56. 56
  Pegram, L. M.; Record, M. T. Hofmeister salt effects on surface tension arise from partitioning of anions and cations between bulk water and the air-water interface. J. Phys. Chem. B 2007, 111, 5411– 5417, DOI: 10.1021/jp070245z
  There is no corresponding record for this reference.
57. 57
  dos Santos, D. J. V. A.; Müller-Plathe, F.; Weiss, V. C. Consistency of Ion Adsorption and Excess Surface Tension in Molecular Dynamics Simulations of Aqueous Salt Solutions. J. Phys. Chem. C 2008, 112, 19431– 19442, DOI: 10.1021/jp804811u
  There is no corresponding record for this reference.
58. 58
  Boström, M.; Kunz, W.; Ninham, B. W. Hofmeister effects in surface tension of aqueous electrolyte solution. Langmuir 2005, 21, 2619– 2623, DOI: 10.1021/la047437v
  There is no corresponding record for this reference.
59. 59
  D’Auria, R.; Tobias, D. J. Relation between surface tension and ion adsorption at the air-water interface: a molecular dynamics simulation study. J. Phys. Chem. A 2009, 113, 7286– 7293, DOI: 10.1021/jp810488p
  There is no corresponding record for this reference.
60. 60
  Sun, L.; Li, X.; Hede, T.; Tu, Y.; Leck, C.; Ågren, H. Molecular dynamics simulations of the surface tension and structure of salt solutions and clusters. J. Phys. Chem. B 2012, 116, 3198– 3204, DOI: 10.1021/jp209178s
  There is no corresponding record for this reference.
61. 61
  Smith, R. Ion clustering in aqueous salt solutions near the liquid/vapor interface. Condens. Matter Phys. 2016, 19, 23002, DOI: 10.5488/CMP.19.23002
  There is no corresponding record for this reference.
62. 62
  Ghosal, S.; Hemminger, J. C.; Bluhm, H.; Mun, B. S.; Hebenstreit, E. L. D.; Ketteler, G.; Ogletree, D. F.; Requejo, F. G.; Salmeron, M. Electron Spectroscopy of Aqueous Solution Interfaces Reveals Surface Enhancement of Halides. Science 2005, 307, 563– 566, DOI: 10.1126/science.1106525
  There is no corresponding record for this reference.
63. 63
  Krisch, M. J.; D’Auria, R.; Brown, M. A.; Tobias, D. J.; Hemminger, C.; Ammann, M.; Starr, D. E.; Bluhm, H. The Effect of an Organic Surfactant on the Liquid–Vapor Interface of an Electrolyte Solution. J. Phys. Chem. C 2007, 111, 13497– 13509, DOI: 10.1021/jp073078b
  There is no corresponding record for this reference.
64. 64
  Onorato, R. M.; Otten, D. E.; Saykally, R. J. Measurement of Bromide Ion Affinities for the Air/Water and Dodecanol/Water Interfaces at Molar Concentrations by UV Second Harmonic Generation Spectroscopy. J. Phys. Chem. C 2010, 114, 13746– 13751, DOI: 10.1021/jp103454r
  There is no corresponding record for this reference.
65. 65
  Matubayasi, N.; Sugiyama, S.; Kanzaki, M.; Matuzawa, A. Thermodynamic Studies of the Adsorbed Films and Micelles of Sodium Taurodeoxycholate. J. Colloid Interface Sci. 1997, 196, 123– 127, DOI: 10.1006/jcis.1997.5213
  There is no corresponding record for this reference.
Supporting Information
Supporting Information
The following files are available free of charge. The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.jced.5c00470.
- Conversion of mass fraction to molality (Chapter S1, Table S1); solubility of the inorganic salts (Chapter S2, Tables S2 and S3); preparation of LiCl (Chapter S3, Figure S1); estimation of the surface tension from time series (Chapter S4, Figure S2); surface tension of water including uncertainties (Chapter S5, Table S4); calculation of the combined standard uncertainty of the molality (Chapter S6.1, Table S5); calculation of the combined standard uncertainty of the density (Chapter S6.2); calculation of the combined standard uncertainty of the surface tension (Chapter S6.3, Table S6); calculation of the combined standard uncertainty of the excess surface tension (Chapter S6.4); calculation of the combined standard uncertainty of the surface excess enthalpy (Chapter S6.5); density values at 293.15 and 278.15 K (Chapter S7 and Figure S3); surface tension as a function of the temperature of NaCl, NaI, LiCl, KCl, MgCl₂, and Na₂SO₄ solution (Chapter S8 and Figures S4–S9); surface tension as a function of the molality of NaCl, NaI, LiCl, KCl, MgCl₂, and Na₂SO₄ solution (Chapter S9 and Figures S10–S12); thermodynamic quantities such as surface excess energy, surface excess Helmholtz energy, and surface excess enthalpy at 293.15 K of NaCl, NaI, LiCl, KCl, MgCl₂, and Na₂SO₄ solution (Chapter S10 and Figures S13 to S15); excess surface tension including fits for all aqueous inorganic salt solutions at 293.15 K (Chapter S11, Table S7, and Figures S16 and S17); graphical comparison of the density values with literature data (Chapter S12, Figures S18 and S19); graphical comparison of the surface tension values with literature data (Chapter S13, Figures S20 and S21) (PDF)
- je5c00470_si_001.pdf (1.72 MB)
Terms & Conditions

Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html.

Surface Tension and Surface Thermodynamics of Aqueous Inorganic Salt Solutions in the Atmospherically Relevant Temperature RangeClick to copy article linkArticle link copied!

Journal of Chemical & Engineering Data

License Summary*

Abstract

License Summary*

License Summary*

License Summary*

1. Introduction

2. Experimental Methods

2.1. Materials

2.2. Experimental Procedure

2.3. Density Measurements

2.4. Surface Tension Measurements

3. Results and Discussion

3.1. Density

Figure 1

3.2. Surface Tension

Figure 2

Figure 3

Figure 4

3.3. Excess Surface Tension

Figure 5

3.4. Surface Tension Gradient

3.5. Thermodynamic Quantities of Surface Formation

Figure 6

Figure 7

Figure 8

4. Conclusions

Supporting Information

Terms & Conditions

Author Information

Acknowledgments

References

Cited By

Journal of Chemical & Engineering Data

License Summary*

Article Views

Altmetric

Citations

Recommended Articles

Abstract

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

References

Supporting Information

Supporting Information

Terms & Conditions

Surface Tension and Surface Thermodynamics of Aqueous Inorganic Salt Solutions in the Atmospherically Relevant Temperature Range
Click to copy article linkArticle link copied!