Surface Tension Of Mixture Research Articles

Surface tension measurement and modeling for ternary aqueous solutions of N, N-diethylethanolamine + 2-amino-2-methyl-1-propanol/piperazine + water at T = (293.15 to 318.15) K

The surface tensions of ternary aqueous mixtures composed of N, N-diethylethanolamine (DEEA) (1), 2-amino-2-methyl-1-propanol (AMP) or piperazine (PZ) (2) and H2O (3) was measured at temperatures ranging from (293.15 to 318.15) K and 101 kPa. The systems with mass fractions of w1 = (0.20, 0.25, 0.30 and 0.35) DEEA, and w2 = (0.02 to 0.10) AMP/PZ were investigated. According to the experimental data, the surface tension deviation (Δγ) was obtained and the values were negative under the studied condition. Δγ values were fitted using a polynomial based on the Scatchard model with the average absolute deviation (AAD) ＜ 0.099 mN∙m−1 and the average relative deviations (ARD) ＜ 0.31 %. Moreover, the surface tension values were fitted using Fu-Li-Wang (FLW) and the extended Wilson models. The results revealed that both models can well correlate the surface tension as a function of temperature and composition. FLW model exhibited better fitting results with smaller AAD of less than 0.24 mN∙m−1 and ARD less than 0.68 %, respectively. Additionally, surface enthalpy (Hγ) and surface entropy (Sγ) were estimated based on the temperature dependence of surface tension.

Density, Viscosity, Refractive Index, and Surface Tension of Binary Mixtures of 3-oxa-1,5-Pentanediol with 2-Propanol, 1,2,3-Propanetriol, and 1-Decanol from 283.15 to 403.15 K as Reference Systems for Evaporation Experiments

Density, Viscosity, Refractive Index, and Surface Tension of Binary Mixtures of 3-oxa-1,5-Pentanediol with 2-Propanol, 1,2,3-Propanetriol, and 1-Decanol from 283.15 to 403.15 K as Reference Systems for Evaporation Experiments

Measuring the Surface Tension of Atmospheric Particles and Relevant Mixtures to Better Understand Key Atmospheric Processes.

Aerosol and aqueous particles are ubiquitous in Earth's atmosphere and play key roles in geochemical processes such as natural chemical cycles, cloud and fog formation, air pollution, visibility, climate forcing, etc. The surface tension of atmospheric particles can affect their size distribution, condensational growth, evaporation, and exchange of chemicals with the atmosphere, which, in turn, are important in the above-mentioned geochemical processes. However, because measuring this quantity is challenging, its role in atmospheric processes was dismissed for decades. Over the last 15 years, this field of research has seen some tremendous developments and is rapidly evolving. This review presents the state-of-the-art of this subject focusing on the experimental approaches. It also presents a unique inventory of experimental adsorption isotherms for over 130 mixtures of organic compounds in water of relevance for model development and validation. Potential future areas of research seeking to better determine the surface tension of atmospheric particles, better constrain laboratory investigations, or better understand the role of surface tension in various atmospheric processes, are discussed. We hope that this review appeals not only to atmospheric scientists but also to researchers from other fields, who could help identify new approaches and solutions to the current challenges.

The Gibbs and Butler Equations and the Surface Activity of Dilute Aqueous Solutions of Strong and Weak Linear Polyelectrolyte-Surfactant Mixtures: The Roles of Surface Composition and Polydispersity.

In a previous paper, we applied a combination of direct measurements of both surface tension and surface excess in conjunction with the Gibbs equation to explain features of the adsorption and surface tension of mixtures of surfactants and strong linear polyelectrolytes at the air-water interface. This paper extends that model by including (i) the restrictions of the Butler equation for the behavior of the surface tension of mixed systems and (ii) the surface behavior of surfactant and linear weak polyelectrolyte mixtures, for which the inclusion of measurements of the surface excess and composition is shown to be particularly important. In addition, a closer examination of earlier data at higher concentrations provides evidence that the surface layering that is often observed in polyelectrolyte-surfactant systems is also an average equilibrium phenomenon and is driven by particular aggregation patterns that occur in some systems and not in others. Although the successful application of the Gibbs and Butler equations indicates that strong polyelectrolyte-surfactant systems can be described in terms of an average equilibrium over wide ranges of concentration, we have identified two concentration ranges where polydispersity in either polyelectrolyte molecular weight or composition results in significant time dependence of the surface behavior.

Experimental study of nucleate boiling heat transfer of refrigerant-oil mixture on various modified surfaces

As a crucial component of refrigeration and heat pump system, the evaporator performance directly affects system efficiency. Due to the lubricating oil in the compressor circulating into the evaporator, studying the nucleate boiling heat transfer (NBHT) of refrigerant-oil mixture is of greater practical and guiding significance. Surface modification technology has opened up a new avenue for enhancing NBHT of refrigerant-oil mixture. Therefore, experimental study was conducted on NBHT characteristics of R134a-POE mixture and R1234ze(E)-POE mixture on smooth surface, initial laser-ablated surface, stabilized laser-ablated surface, machined surface, and composite processed surface. The effects of oil concentration (ω), surface microstructure and surface wettability on NBHT of refrigerant were discussed and analyzed, and the underlying heat transfer mechanisms were elucidated. The research indicates that for NBHT of refrigerant-oil mixture, surface microstructure has a greater impact than surface wettability. To enhance heat transfer coefficient (HTC), it is crucial to establish a surface pattern comprising alternating regions of high and low nucleation sites to mitigate bubble interaction and coalescence. Once this objective is attained, enhancing surface wettability can be contemplated. The addition of oil promotes foaming and induces tornado-shaped bubble group, which facilitate heat transfer. However, the rise in mixture viscosity and surface tension exerts a more pronounced adverse effect on heat transfer, outweighing the positive impacts of foaming and tornado-shaped bubble group. Consequently, the presence of oil diminishes HTC. And as ω and heat flux increase, HTC further decreases. Additionally, the increase in vaporization nuclei on modified surface leads to a higher local ω, the increase in ω further weakens the enhanced heat transfer effect of modified surface, and thus narrows the difference in HTC among various modified surfaces. The research results aim to uncover the mechanisms by which surface wettability, surface microstructure, and lubricating oil affect NBHT of refrigerant.

Influence of Hydrogen Bond Acceptors and Water Content on Surface Tension in Glycol-Based Eutectic Mixtures

Influence of Hydrogen Bond Acceptors and Water Content on Surface Tension in Glycol-Based Eutectic Mixtures

Physicochemical properties of extraction solvents for the advanced recycling of spent nuclear fuel

A comprehensive understanding of solvent physicochemical properties is essential to developing advanced solvent extraction processes, such as Advanced PUREX (Plutonium Uranium Reduction Extraction) and GANEX (Group Actinide Extraction), that can safely and efficiently recycle spent nuclear fuel. The densities, viscosities and surface tensions of binary mixtures of tributyl phosphate (TBP) (0.92–3.66 M) in n-dodecane and N,N-di (2-ethyl hexyl)isobutyramide (DEHiBA) (0.69–2.78 M) in n-dodecane were measured at atmospheric pressure from 278.15 to 333.15 K. Through these measurements, empirical expressions to predict the density and viscosity at any molar composition of these solvents within the studied temperature range were constructed and shown to be in good correlation with all experimental data across the studied variables. The relationship between temperature and viscosity of pure TBP and DEHiBA can be described by the Arrhenius equation for viscosity in the temperature range studied. Surface tension measurements (air-liquid interface) were obtained for varying extractant concentrations between 278.15 and 333.15 K, which showed that DEHiBA acts as a surfactant when mixed with n-dodecane whilst TBP exhibits a higher surface tension than n-dodecane.

Finite size effects and optimization of the calculation of the surface tension in surfactant mixtures at liquid/vapour interfaces

The surface tension of monolayers with mixtures of anionic and nonionic surfactant at the liquid/vapour interface is studied. Previous works have observed that calculations of the surface tension of simple fluids show artificial oscillations for small interfacial areas, indicating that the surface tension data fluctuate due to the finite size effects and periodic boundary conditions. In the case of simulations of monolayers composed of surfactant mixtures, the surface tension not only oscillates for small areas but can also give non-physical data, such as negative values. Analysis of the monolayers with different surfactant mixtures, ionic (DTAB, CTAB, SDS) and nonionic (SB3-12), was done for density profiles, parameters of order and pair correlation functions for small and large box areas and all of them present similar behaviour. The fluctuations and the non-physical values of the surface tension are corrected when boxes with large interfacial areas are considered. The results indicate that in order to obtain reliable values of the surface tension, in computer simulations, it is important to choose not only the correct force field but also the appropriate size of the simulation box.

A unified surface tension model for multi-component salt, organic, and surfactant solutions.

Despite the fact that the surface tension of liquid mixtures is of great importance in numerous fields and applications, there are no accurate models for calculating the surface tension of solutions containing water, salts, organic, and amphiphilic substances in a mixture. This study presents such a model and demonstrates its capabilities by modelling surface tension data from the literature. The presented equations not only allow to model solutions with ideal mixing behaviour but also non-idealities and synergistic effects can be identified and largely reproduced. In total, 22 ternary systems comprising 1842 data points could be modelled with an overall root mean squared error (RMSE) of 3.09 mN m-1. In addition, based on the modelling of ternary systems, the surface tension of two quaternary systems could be well predicted with RMSEs of 1.66 mN m-1 and 3.44 mN m-1. Besides its ability to accurately fit and predict multi-component surface tension data, the model also allows to analyze the nature and magnitude of bulk and surface non-idealities, helping to improve our understanding of the physicochemical mechanisms that influence surface tension.

In uence of irradiation on the stability of extraction mixtures based on methyltri-<i>n</i>-octylammonium carbonate

The radiation-thermal stability of extraction mixtures based on methyltrioctylammonium carbonate has been studied. The volumes and maximum rate of release of gaseous products at atmospheric and elevated pressures have been determined. It is shown that exothermic processes do not occur in the studied mixtures under experimental conditions. Irradiation up to a dose of 1 MGy has little e ect on the density, viscosity, and surface tension of mixtures, but signi cantly reduces the rate of phase separation. The distribution coe cients of Am(III) in the system of 50% MTOA carbonate in toluene are practically independent of the absorbed dose; however, irradiation has a noticeable e ect on the composition of the extractable americium complexes. The results of the study of extraction systems showed their high radiation-thermal stability.

Physico-chemical characterisation of glycerol- and ethylene glycol-based deep eutectic solvents

Deep eutectic solvents are of significant interest to numerous applications including cryopreservation, chemical synthesis, lubrication, energy storage, catalysis, and self-assembly. However, to date there have been few rigorous and systematic studies of the physico-chemical and thermal properties of these solvents. This means that conclusive structure-function relationships are difficult to define within the context of the current literature. Here, we present the viscosity, refractive index, density, surface tension, and thermal behaviour of mixtures of either glycerol or ethylene glycol with choline chloride, betaine, or L-proline, as neat fluids and in the presence of water. We demonstrate that changing the ratio of hydrogen bond donor to hydrogen bond acceptor has only a small effect on the physico-chemical properties, while the addition of even small quantities of water has a significant effect. Despite rigorous studies, we demonstrate that determining the eutectic point of these mixtures is not straight-forward and that the definition of a ‘deep’ eutectic solvent may need to be reviewed in the frame of ideal mixing theory.

Unusual interfacial behaviour of mixtures of 2,2,2-Trifluoroethanol with hydrogenated alcohols

New experimental data is reported for the surface tension of mixtures of 2,2,2-trifluoroethanol with three hydrogenated alcohols, namely ethanol, 1-propanol and 1-butanol, at 293.2 K along the full composition range. The phase equilibria, bulk properties of the mixtures and interfacial properties were modeled with soft-SAFT combined with the density gradient theory. Excellent agreement was found between predictions from the theory and the experimental results, the model allowing interpreting the interfacial behaviour of the mixtures, providing a microscopic explanation of the unusual interfacial behavior of these particular mixtures. Negative aneotropy (minima in the surface tension vs composition curve) is observed for the three mixtures. Negative aneotropy is a rare and poorly understood phenomenon usually associated to weak intermolecular interactions between the components of the mixture, which is not the case in these systems as the components interact strongly through hydrogen bonding. To the best of our knowledge, this is the first reported example of this type of negative aneotropy.

Neural Network Model of Surface Tension of Hydrocarbon–Alcohol Binary Mixtures

Since the correlation of surface tension of hydrocarbons and alcohol mixtures has great importance, this study is aimed to propose an artificial neural network model to correlate this thermodynamic property. To calculate the best network architecture and the optimal number of neurons, five sets of input variables and two transfer functions are examined. The results reveal that a feed-forward network with the structure of 5-14-1 and logsis and purelin as transfer functions for hidden and output layers, respectively, leads to the best accuracy. Moreover, it is revealed that choosing temperature, mole fraction, molecular weight of hydrocarbons, molecular weight of alcohols, and critical temperature as input variables can be efficient for an accurate correlation of the surface tension of selected chemicals. The results of the proposed artificial neural network model are also compared to the Shereshefsky and Langmuir thermodynamic models. The results obtained from 34 binary mixtures show the generality and acceptable accuracy of the proposed feed-forward network (with an average absolute relative deviation [AARD] of 0.36%) compared to the Shereshefsky (with an AARD of 0.37%, obtained for 31 binary mixtures) and Langmuir (with an AARD of 0.52%) thermodynamic models.

Measurement and modeling of surface tension of binary mixtures containing N,N-dimethylcyclohexylamine and alcohols

In this work, the surface tension of the six binary systems containing N, N-dimethylcyclohexylamine (DMCHA) and alcohol (1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol or 1-decanol) was measured over the whole DMCHA concentration at the temperatures of (293.15 to 323.15) K and 101 kPa. Based on the experimental data, surface tension deviation (Δσ) was calculated. The values are positive for all the binary mixtures and decreased with chain length of alcohols. The results were correlated using different models. The surface tensions were fitted by Fu-Li-Wang (FLW) model with stand deviations (S) less than 0.122. The surface tension deviations were well fitted by Myers-Scott (MS) and Redlich-Kister (RK) equations with S ≤ 0.052. Additionally, according to the relationship of surface tension and temperature, the thermodynamic properties, surface enthalpy (Hγ) and surface entropy (Sγ), were also estimated. All the above results were further analyzed and discussed in terms of temperature, composition and chain length of alcohol.

Linking surface tension to water polarization with a new hypothesis: The Ling-Damodaran Isotherm.

Studying aqueous solutions of complex (bio)polymers is essential from both theoretical and practical perspectives. To understand the principles that govern the properties of these solutions is pivotal for the study of biological processes, considering that the most distinguished components of the cells are polymers (proteins, nucleic acids). These macromolecular aqueous systems, known as colloids, has raise the interest of scientists in recent years. It is known that several physicochemical properties deviate from ideal behaviour in this kind of solutions and that the physical state of water is different compared to its pure state. Particularly, the surface tension of such mixtures often shows a peculiar profile at semi-dilute and concentrated conditions. Here, we joined the colloidal concept of water polarization (proposed in the Association-Induction Hypothesis) with Damodaran's formalism for surface tension to theoretically derive a compelling mathematical model that explains the behaviour of polymer solutions. We measured the surface tension and osmolarity of different polyethylene oxide solutions and we used the ACDAN fluorescence probe to assess the water dipolar relaxation (polarization) in these mixtures. As a proof of concept, we also studied the influence of these polymer solutions on lipid interfaces. Our isotherm model explains the experimental observations with a unifying view that correlates with other measured properties, such as osmolarity and water dipolar relaxation. This provides a link between interfacial and bulk physicochemical properties of polymer solutions, also giving a new framework for studying the interaction of colloidal systems with lipid membranes interfaces.

Predictive modeling on the surface tension and viscosity of ionic liquid-organic solvent mixtures via machine learning

Backgrounda comprehensive collection of reliable open-source data was compiled, encompassing 3454 data points for surface tension and 28,548 data points for viscosity of IL-organic solvent mixtures. Methodspredictive modeling was conducted for these two crucial properties using a combination of the GC method and three well-known machine learning algorithms: Artificial Neural Network (ANN), eXtreme Gradient Boosting (XGBoost), and Light Gradient Boosting Machine (LightGBM). The modeling results demonstrate that the GC models, employing all three machine learning algorithms, offer dependable predictions. Significant FindingsThe XGBoost-based model exhibits the most superior performance in surface tension predictions, achieving a square correlation coefficient (R2) of 0.9829 and a mean absolute error (MAE) of 0.0007 N/m for the randomly generated test dataset. In contrast, the ANN-based model with optimized neurons delivers the best predictive performance in viscosity, achieving an R2 of 0.9582 and an MAE of 0.0975 Pa·s. Furthermore, the Shapley Additive Explanations (SHAP) analysis is performed to evaluate the impact of each feature on the prediction of surface tension and viscosity in IL-organic solvent binary mixtures. The results reveal that the mole fraction of IL has the greatest positive effect on the prediction for both surface tension and viscosity.

Insights into the estimation of surface tensions of mixtures based on designable green materials using an ensemble learning scheme

Precise estimation of the physical properties of both ionic liquids (ILs) and their mixtures is crucial for engineers to successfully design new industrial processes. Among these properties, surface tension is especially important. It’s not only necessary to have knowledge of the properties of pure ILs, but also of their mixtures to ensure optimal utilization in a variety of applications. In this regard, this study aimed to evaluate the effectiveness of Stochastic Gradient Boosting (SGB) tree in modeling surface tensions of binary mixtures of various ionic liquids (ILs) using a comprehensive dataset. The dataset comprised 4010 experimental data points from 48 different ILs and 20 non-IL components, covering a surface tension range of 0.0157–0.0727 N m−1 across a temperature range of 278.15–348.15 K. The study found that the estimated values were in good agreement with the reported experimental data, as evidenced by a high correlation coefficient (R) and a low Mean Relative Absolute Error of greater than 0.999 and less than 0.004, respectively. In addition, the results of the used SGB model were compared to the results of SVM, GA-SVM, GA-LSSVM, CSA-LSSVM, GMDH-PNN, three based ANNs, PSO-ANN, GA-ANN, ICA-ANN, TLBO-ANN, ANFIS, ANFIS-ACO, ANFIS-DE, ANFIS-GA, ANFIS-PSO, and MGGP models. In terms of the accuracy, the SGB model is better and provides significantly lower deviations compared to the other techniques. Also, an evaluation was conducted to determine the importance of each variable in predicting surface tension, which revealed that the most influential factor was the mole fraction of IL. In the end, William’s plot was utilized to investigate the model's applicability range. As the majority of data points, i.e. 98.5% of the whole dataset, were well within the safety margin, it was concluded that the proposed model had a high applicability domain and its predictions were valid and reliable.

Polar and dispersive surface tension components of water-guanidinium chloride (Gdmcl) binary mixtures

Interfacial interaction of water with guanidinium chloride (GdmCl) is crucial to understanding protein solubility and denaturing mechanism. However, molecularly resolved parameters such as polar and dispersive surface energy components of water-GdmCl mixtures remain unknown. Here, we developed a method to determine water-GdmCl mixture surface tension and its components using four different substrates including polydimethylsiloxane (PDMS), silicone, polyethylene, and polystyrene. Results show all six combinations, PDMS-silicone, PDMS-polystyrene, PDMS-polyethylene, silicone-polyethylene, silicone-polystyrene, and polyethylene-polystyrene can estimate similar trend of total surface tension, polar and dispersive components with respect to salt concentration changes. Silicone-polyethylene pairs yield the most accurate surface tension compared to others because silicone and polyethylene have large distinctive surface energy differences. Results show that polar components increase from 51 mJ/m2 to 64 mJ/m2 when salt concentration increases; dispersive components decrease from 21 mJ/m2 to 15 mJ/m2 when salt concentration increases. Total surface tension increases from 72.8 mJ/m2 to 78.1 mJ/m2 when GdmCl increases from 0% to 40 wt%. The results of this study can elucidate molecular interaction between water and GdmCl.

Theoretical analysis of the spray characteristics of ternary blends of diesel, biodiesel, and long-chain alcohols inside a combustion chamber

The diesel and alcohol blends are potential alternatives to biogenic fuels to reduce biodiesel consumption, which might help reduce toxic emissions. Due to the high-quality requirements for engines, the fuel fundaments in the fluid properties and its impact on the macroscopic spray characteristics. Herein, a study proposed the experimental determination of density, viscosity, and surface tension for ternary mixtures of diesel (D) + biodiesel (B) + 1-hexanol (H) and + 1-octanol (O) at 298.15 K. These properties comply with the limits established by the EN 14214 and ASTM D975 standards. Thus, to extend the impact of these results, a theoretical analysis via CFD is carried out in ANSYS FLUENT ® by considering a macroscopic and isothermal system, which involved the independence tests of meshing and turbulence modeling. The numerical results evaluated the spray tip penetration, spray angle, spray morphology, eddy turbulence, and relation of spray volume and surface spray area at the injection pressure of 90 MPa using the Large Eddy Simulation (LES) model. The behavior of the spray tip penetration and spray angle agree with experimental values reported in the literature for diesel fuel. This condition validates our simulations for biodiesel and ternary blends. Therefore, the use of alcohols and biodiesel as new additives to diesel improves the macroscopic spray characteristics, and some ternary mixtures showed similar behavior to conventional diesel: spray tip penetration (70D5B25O, 70D25B5H, and 70D25B5O) and spray angle (70D25B5H, 70D15B15H, 80D5B15O, and 80D15B5). The mixture of 70D25B5H agrees with both spray characteristics; therefore, this mixture could be considered an alternative fuel to conventional diesel. Hence, this analysis presents the essential elements to visualize the macroscopic spray characteristics and the fluid properties. This knowledge serves as a foundation for elucidating the intricate dynamics of spray during combustion processes and the development of complementary studies aimed at optimizing engine performance.

Molecular simulation and experimental validation for surface tension of new Low-GWP refrigerant mixtures R32/CF3I and R1123/CF3I

This study demonstrated a new procedure for measuring surface tension using molecular dynamics (MD) simulations. The surface tension was measured by the differential capillary rise method for refrigerant mixtures R1123/CF3I and R32/CF3I, which have a low global warming potential. The information of the saturated density in the low-temperature region, which was necessary for data reduction, was supplemented by an MD simulation, which was validated using accurate measurement data near the critical point. The surface tension calculated from the pressure tensor obtained by the MD simulation deviated considerably. However, the surface tension obtained from the simulated density and composition in the vapor and liquid phases by the parachor method was in agreement with the measured values within the measurement uncertainty ranges from 0.15 mNm−1 to 0.35 mNm−1. The simulated density distribution showed positive surface activity at the vapor–liquid interface, indicating that R32 and R1123, with smaller polarities, tended to aggregate on the liquid surface. This helps interpret the empirically postulated decrease in the surface tension of the mixtures due to the concentration of substances with lower surface tension at the vapor–liquid interface.