Molar Surface Research Articles

Synthesis and characterization of physicochemical properties of new ether-functionalized amino acid ionic liquids

Abstract Since the effect of ether functionalities on physicochemical properties varies strongly, So the experimental study of in properties is still primarily important for ether-functionalized ionic liquids to be properly applied, as well as for providing reference data for more reliable predictions. In this work, two novel ether-functionalized amino acid ionic liquids 1-(2-methoxyethyl)-3-methylimidazolium threonine and 1-(2-ethoxyethyl)-3-methylimidazolium threonine were synthesized and characterized. Physicochemical properties, including density, surface tension, viscosity and refractive index were measured at different temperatures and atmospheric pressure. According to the volumetric properties of ether-functionalized ionic liquids, the contribution of an ether O atom in the alkoxy side chain to molecular volume, standard entropy and lattice energy were estimated to be 0.0102 nm3, 13 J·K−1·mol−1 and 3 kJ·mol−1, respectively. Combined the molar surface Gibbs energy with Lorentz-Lorenz relationship, an equation for predicting surface tensions of ionic liquids was obtained, and the predicted values agree well with the experimental data. Moreover, an equation of the polarity coefficient P was proposed and the polarity of other ionic liquids was estimated. The polarity of the same series of ionic liquids decreases with the length of the alkoxy chain, the hydrophilicity becomes relatively weak, and the hydrophobicity is relatively enhanced. Using Eyring's viscosity equation and thermodynamic formula, an expression for calculating the viscous flow activation energy of ionic liquids was obtained, and the values were in good agreement with the values calculated by the Arrhenius equation.

Measurement of density, viscosity and surface tension of tri-ethylene glycol + 1,3-propanediamine mixtures & their computational chemistry and spectral analysis

For liquid and liquid mixtures, density (ρ), viscosity (η) and surface tension (γ) are seen as important basic data. This research reported the data of ρ, η and γ for the binary mixture of tri-ethylene glycol (TEG) + 1,3-propanediamine (PDA) at p = .1 MPa and T = (293.15 to 318.15) K within the whole molar fraction range, finding the maximum of η and γ values when the mole fraction of TEG was x1 ≈ 0.65. After that, excess molar volume (VmE), viscosity deviation (Δη), and surface tension deviation (Δγ) were carefully calculated, and the minimum VmE values and the maximum Δγ values were obtained when the molar fraction of TEG was at x1 ≈ 0.50; however, the maximum Δη values shifted from x1 ≈ 0.60 to x1 ≈ 0.66. And then, the Redlich-Kister (R-K) equation fitting was performed on above parameters to evaluate the coefficient and standard deviation, apparent molar volumes (Vφ, 1 and Vφ, 2) and partial molar volumes (V1¯ and V2¯). Meanwhile, Gaussian 09 software was used to further analyze the intermolecular force and to calculate the dissociation energy and bond length of the mixture, and the interaction of PDA with TEG were discussed on the basis of FTIR, UV–Vis and FLS spectral technologies. The results showed that there were hydrogen-bond interactions between the nitrogen atoms in PDA and the hydroxyl hydrogen atoms in TEG.

A comprehensive study of the thermophysical properties of reline and hydrated reline

In this work, a physicochemical characterization of the Deep Eutectic Solvent, reline (formed by chloline chloride and urea in a molar ratio 1:2) and one of its aqueous mixtures (xreline = 0.645) has been made at atmospheric pressure (0.1 MPa) in a wide range of temperatures (288.15–338.15) K for reline and (278.15–338.15) K for the aqueous mixture. The measured properties were: density, speed of sound, refractive index, isobaric molar heat capacity, surface tension, kinematic and dynamic viscosity and electrical conductivity. Additionally, from these experimental results, some derivate properties such as isobaric thermal expansibility, isentropic compressibility, molar refraction, free volume and entropy and enthalpy of surface formation have been obtained. Taking into account the observed behaviour the introduction of water, at the considered composition, only modify drastically the dynamic viscosity and electrical conductivity.

A systematic review of second molar distal surface caries incidence in the context of third molar absence and emergence.

Objective The aim of this systematic review was to gain a greater insight into the incidence rates of distal surface caries (DSC) on second permanent molars.Data sources A literature search using the Cochrane Library, Lilacs, Embase and Medline via Ovid retrieved English and non-English language articles from inception to June 2016. The electronic searches were supplemented with reference searching and citation tracking. Reviewers independently and in duplicate performed data extraction and completed structured quality assessments using a validated risk of bias tool for observational studies and categorised the summary scores.Data selection The search yielded 81 records and, after application of inclusion and exclusion criteria, two incidence studies were included in this systematic review.Data extraction The DSC incidence was reported in one study as relative risk (RR = 2.53; 95% CI, 1.55 to 4.14) adjacent to erupted, (RR = 0.83; 95% CI, 0.11 to 6.04) soft tissue impacted and (RR = 1.44; 95% CI, 0.55 to 3.72) bony impacted third molars in comparison to when the third molar was absent with a 25-year follow-up. The second study reported a DSC incidence of 100 surface-years (1% of all sites) with an 18-month follow-up period.Conclusions Both cohort studies indicated that DSC incidence was higher when third molars were erupted in the intermediate term, but greater over the long term for an ageing male population. However, further high-quality research is required to improve the accuracy of these findings.

Size Dependence of the Integral Melting Enthalpy and Entropy of Nanoparticles.

Precise thermodynamic relations to describe the size-dependent integral melting enthalpy and entropy of nanoparticles were deduced by virtue of designing a thermochemical cycle. The differences between integral and differential melting enthalpy and integral and differential melting entropy of nanoparticles were discussed. Nano-Sn of different sizes was prepared by means of chemical reduction, and differential scanning calorimetry (DSC) was utilized to obtain the melting temperature, melting enthalpy, and melting entropy. The experimental results agree with the theoretical predictions and literature results, demonstrating that the melting temperature, enthalpy, and entropy decrease with decreasing particle size and linearly vary with the reciprocal of particle size within the experimental size range. The variations of melting enthalpy and entropy with particle size mainly depend on the molar surface area, the interfacial tension, and the temperature coefficient of interfacial tension. These findings offer a better understanding of the effect of particle size on the melting thermodynamic behaviors of nanoparticles at different melting stages.

Physicochemical properties of ether-functionalized ionic liquids [CnOC2mim][Gly] (n = 1–5)

A novel ionic liquid 1-ethoxyethyl-3-methylimidazolium glycine ([C2OC2mim][Gly]) was prepared and characterized by 1H NMR spectroscopy, 13C NMR spectroscopy, elemental analysis and thermogravimetric analysis. The density, surface tension and refractive index of [C2OC2mim][Gly] were measured in T = (288.15–328.15) K using the standard addition method. Based on experimental data, physicochemical properties molar volume, parachor, surface tension, the molar surface Gibbs energy, the molar vaporization enthalpy, thermal expansion coefficients, molar refraction and refractive index of the homologues [CnOC2mim][Gly] (n = 1–5) were predicted using semiempirical methods. The predicted values were in good agreement within an order of magnitude with the experimental ones.

Prediction of oil/water interfacial tension containing ionic surfactants

This study introduces a new approach to predict interfacial tension (IFT) at oil/water interfaces in the presence of ionic surfactants. Experimental data for sodium dodecylsulphate (SDS), decyltrimethylammonium bromide (C10TAB) and dodecyltrimethylammonium bromide (C12TAB) at hydrocarbon/water interfaces are used to validate the new approach. The model parameters, including molar surface area (ω) and bulk-surface distribution coefficient of surfactant (KS) are obtained by fitting the proposed equation to the literature data. The change of model parameters at different interfaces is discussed. In all cases investigated, the deviation of results for the suggested equations is less than previous work. A good agreement between results and experimental data is obtained in the concentration region below and near the critical micelle concentration.

In‐situ microcalorimetry study on thermodynamic functions of Cu 2 O nanocubes

Four different sizes of cuprous oxides (Cu2 O) nanocubes in the range of 40–120 nm were synthesised by liquid phase reduction method. The morphology, size, and structure of synthesised Cu2 O nanocubes were characterised by scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. In-situ microcalorimetry was used to calculate the conventional and surface thermodynamic functions of Cu2 O nanocubes by combining thermodynamic principles and transition state theory. The effect of particle size on conventional thermodynamic functions and surface thermodynamic functions were investigated and analysed, whose results were supported by the established thermodynamic models. Results showed that both the standard molar enthalpy of formation and the standard molar entropy of formation were increased with decreasing particle size, while the standard molar Gibbs energy of formation decreased. Also, the molar surface Gibbs energy, molar surface enthalpy, and molar surface entropy grew with the reduction of particle size, which correlated well with the models. Such a property is of scientific significance for enriching and developing disciplines such as surface physics and surface thermodynamics.

Solvent-free preparation of hierarchical 4A zeolite monoliths: Role of experimental conditions

A series of novel self-supporting hierarchically porous zeolite monoliths with micropores and macropores were successfully prepared using polymethyl methacrylate (PMMA) microbeads as sacrificial template via solvent-free strategy. The effects of several synthesis parameters, such as Na/Al molar ratio, H2O/metakaolin (MK) mass ratio, MK/PMMA mass ratio and curing time on the structure and morphology of hierarchical zeolite monoliths were systematically investigated. Multiple techniques, including SEM, XRD, FTIR, XRF, BET, MIP and TG-DTG were used to test the properties of resultant products. The experimental results show that hierarchical 4A zeolite monoliths could be obtained at Na/Al molar ratio of 1.2:1, H2O/MK mass ratio of 1.1:1, MK/PMMA mass ratio of 50/50, curing temperature of 70 °C for 24 h and calcination temperature of 550 °C for 2 h. The SiO2/Al2O3 molar ratio and BET specific surface area were found to be 1.92 and 57.67 m2/g, respectively. The diameter of macropore pores were mainly in the range of 840–4130 nm.

The excess molar volume and the molar surface Gibbs energy of the binary of the ether-functionalized ionic liquids [C22O1IM][TfO] with ethanol and isomeric propanols at T = (288.15–318.15) K

The density and surface tension for the binary mixtures of ionic liquid (ILs) [C22O1IM][TfO] with ethanol, 1-propanol and 2-propanol are measured across the entire range of mole fraction at T = (288.15–318.15) K. The excess molar volumes of the binary mixtures are calculated, the relationship between VE and the mole fraction and temperature are explored. Especially, the term, △VE/△T is proposed to describe the interaction between the solvent and solute quantificationally. The molar surface Gibbs energy of the binary mixtures are obtained based on the density and surface tension, and the interaction between the components in both liquid and surface phase of the binary mixture is discussed. And its applications are also explored, including the estimation of surface tension for the binary mixtures and the improvement of the traditional Eötvös equation. At the same time, the polarity of the binary mixtures of [C22O1IM][TfO] with alcohols is obtained.

Adsorption selectivity of cubic nano-CeO2 and effect of particle size on adsorption thermodynamics

Nanoparticles can effectively remove organic dyes from wastewater due to their excellent adsorption performances which are closely related to particle size. Herein, the relations between the thermodynamic properties and the particle size were deduced, and the influence mechanisms were also discussed. Then the adsorptions of four dyes on cubic nano-CeO2 were investigated. We found that cubic nano-CeO2 has strong adsorption selectivity for four dyes and the size dependence of the adsorption thermodynamic properties. This strong selectivity is attributed to electrostatic interaction and hydrogen bonding. Furthermore, with the particle size decreasing, the logarithm of standard adsorption equilibrium constant (lnKo) increase, while the standard molar Gibbs energy change of adsorption (ΔadsGmθ), the standard molar adsorption enthalpy change (ΔadsHmθ) and the standard molar adsorption entropy change (ΔadsSmθ) decrease, and there are good linear relationships between this thermodynamic properties and the reciprocal of the particle size. The essences of effect of particle size on adsorption thermodynamics are that lnKθ and ΔadsGmθ are influenced by both the molar surface area and the difference in surface tensions after adsorption, ΔadsHmθ by the molar surface area, the differences in surface tensions and in temperature coefficients of surface tensions, ΔadsSmθ by the molar surface area and the difference in temperature coefficients of the surface tensions.

The molar surface Gibbs energy and polarity of ether-functionalized ionic liquids

Ether groups are well-known for their unique contribution to low viscosity and high conductivity, hence ether-functionalized ionic liquids (EFILs) have been widely studied and successfully employed in various applications. Three EFILs 1-(2-methoxyethyl)-3-methylimidazolium chloride, 1-(2-ethoxyethyl)-3-methylimidazolium chloride and 1-(2-ethoxyethyl)-3-methylimidazolium bromide were prepared and characterized. Their surface tension, density and refractive index in the range of T = (288.15–328.15) K were measured and the molar surface Gibbs energy, gs, were calculated. Combined gs with Lorentz-Lorenz equation, an expression for predicting surface tensions of ionic liquids was obtained, and the predicted values were in good agreement with the experimental ones. According to the gs, the vaporisation enthalpies were predicted and the association enthalpies of ionic liquids were estimated. A new method for estimating the difference of heat capacities between the vapour phase and the liquid phase of ionic liquids was put forward, and the estimated values were in the same order of magnitude as the Verevkin method. Moreover, the concept of the polarity coefficient P for ionic liquids was proposed and the polarity of many ionic liquids was estimated.

The molar surface quasi-Gibbs energy and its application to the binary mixtures of 1-(2-methoxyethyl)-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide [MOEMIM][NTf2] with methanol and ethanol

The IL (ionic liquid) 1-(2-methoxyethyl)-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide [MOEMIM][NTf2] was prepared and confirmed by 1H NMR (1H nuclear magnetic resonance) spectroscopy and 13C NMR (13C nuclear magnetic resonance) spectroscopy. The density and surface tension for the binary mixtures of [MOEMIM][NTf2] with methanol and ethanol were measured across the entire range of mole fraction (x1 = 0.0000–1.0000) at T = (288.15–318.15) K. The average molar volumes of the binary mixtures were calculated from the experimental density, which increased with the increase of mole fraction and temperature. The excess molar volumes, VmE, were obtained and fitted by Redlich–Kister equation. The interaction between ionic liquid and alcohol is the strongest efficient packing and/or attractive interaction at the minimum point. The lower the temperature was, the smaller the absolute value of excess molar volume was. The new function – the molar surface quasi-Gibbs energy of mixtures was obtained by us in this work. On a basis of molar surface quasi-Gibbs energy of mixtures, a new Eӧtvӧs equation was obtained of mixtures and applied to binary mixtures of [MOEMIM][NTf2] with alcohols. The absolute value of the slope of the new Eötvös equation is the mole surface entropy, s, and the intercept is the molar surface enthalpy, h, which is temperature-independent. The deviation of molar surface quasi-Gibbs energy, Δgs, of mixtures for [MOEMIM][NTf2] with methanol and ethanol were calculated. Δgs was well fitted by Redlich–Kister equation. In terms of Redlich–Kister’s parameters, Ai, a new method for estimating the surface tension, γ, with any component of the mixtures is proposed and the estimated values, γ (est.), are in good agreement with the corresponding experimental ones, γ(exp.).

Influence of pH, temperature, and sisal pulp on the production of cellulases from Aspergillus sp. CBMAI 1198 and hydrolysis of cellulosic materials with different hemicelluloses content, crystallinity, and average molar mass

This study aimed to evaluate the production of cellulases from Aspergillus sp. CBMAI 1198, through solid-state fermentation, and their actions on different cellulosic materials (microcrystalline cellulose, sisal pulp, and filter paper). The influence of pH, temperature, and composition of substrates (sisal pulp and wheat straw), on the filter paper activity (FPase) of the cellulases produced from these substrates, was investigated using a complete central factorial composite design. Low temperature (32 °C), sisal pulp content (25%), and pH (5.0) led to the production of enzymes with higher activity (0.244 UmL−1). The results on the reducing sugars produced by the enzymatic hydrolysis of microcrystalline cellulose, sisal pulp, and filter paper showed that the cellulosic material with a higher content of hemicelluloses and lower crystallinity (filter paper) exhibited the better result (8.04 μmol mL−1). Non-hydrolyzed microcrystalline cellulose, sisal pulp, and filter paper were withdrawn from the medium during the reaction, and changes in their physicochemical properties were monitored assessing changes in molar mass, crystallinity index, surface morphology (scanning electron microscopy), and fiber lengths and thicknesses (MorFi technique). This approach on the properties of non-hydrolyzed fibers differentiates this study from those found in the literature. The results showed that cellulases were successfully produced from Aspergillus sp. and, despite the low yield, these enzymes hydrolyzed cellulosic materials with different properties. The approach of the present study, as well as the set of results obtained, added novelty to the respective area, and are important for the deepening of the investigations.

The application of molar surface Gibbs energy to predicting ILs' properties

1-alky-3-methylimidazolium taurate ionic liquid, [Cnmim]Tau (n = 3,4) were synthesized by neutralization method and were confirmed by 1H NMR and 13C NMR. Standard addition method was applied to determine the densities, surface tensions and refractive indexes for [Cnmim]Tau (n = 3,4). By using Tong's vaporization enthalpy model, the vaporization enthalpies of [Cnmim]Tau (n = 3,4) and some other ILs were estimated. The association enthalpies, ΔAHm0 of them in gas phase were estimated. Combined gs with Lorentz–Lorenz equation, a semi-empirical surface tension predicting equation can be obtained. The surface tensions of [Cnmim][Tau](n = 3,4), some other ILs and some molecular liquids were predicted. The predicted values are highly similar with the corresponding experimental ones. In current work, we put forward a new method for predicting ΔlgCp,m0,which was used for [Cnmim]Tau (n = 3,4) and other ILs. Our results are in the same order magnitude with Verevkin's, but ours are relatively higher.

Cognateosymtes serraticoxae, new genus, new species, a pleustid amphipod from the Sea of Japan (Crustacea: Amphipoda: Gammaridea: Pleustidae: Eosymtinae).

The new genus Cognateosymtes gen. nov. and new species C. serraticoxae sp. nov. are described from the shelf of western Sakhalin Island. The new genus has a set of features specific to the subfamily Eosymtinae: strongly ridged molar grinding surface of mandible and presence of a medial seta; inner plate of maxilla 1 with 2 strong apical plumose setae; inner plate of maxilla 2 with 2 strong submarginal setae, positioned subapically; pereopods 1 and 2 (gnathopods), propodal palmar margins lacking submedial tooth. Cognateosymtes differs from Eosymtes by the combination of character states: antenna 1, peduncular segment 1 with strong anterodistal processes; outer and inner plates of maxilla 2 with numerous apical setae; maxilliped, palp segment 2 linear, inner margin densely setose; coxae 1-3, posterodistal cusps multiple; dactylus of pereopods 3-7 the short. The key to the amphipod genera of the subfamily Eosymtinae Bousfield Hendrycks, 1994 is given.

MORPHOLOGICAL SUBSTANTIATION OF APPLICATION OF THE DEVELOPED STOMATOLOGIC MEDICAL PREPARATION BY THE BIOLOGICAL METHOD OF TREATINMENT OF THE PULPITIS

Aim. This study was designed for the morphological assessment of the state of tooth pulp tissues after simulated acute 29 Kubanskij nauchnyj medicinskij vestnik 2018; 25 (5) trauma under the influence of the developed dental treatment pad and three analogues in the treatment of deep caries and acute focal pulpitis.Materials and methods.In the course of the experiment the study was conducted on white laboratory rats. The cavities on the molar chewing surface of the upper jaw were formed by spherical burs. The experimentally formed lesions of the surface layer of the pulp were treated using the developed dental preparation and three analogues. Laboratory animals were withdrawn from the experiment on days 3, 7 and 30. Animal teeth were put in a 10% neutral formalin solution, decalcified for 3 days and then put into a mounting medium. The slices obtained had a thickness of 5-15 μm.Results. In the course of the experimental study we detected the activation of reactive and compensatory processes in the tooth pulp tissue with the preservation of its viability by using the developed dental therapeutic preparation and the Biodentin as a comparison preparation on the 30th day of the experiment. Histologically, these changes were expressed in an increase in the level of metabolic processes and in the activation of cellular elements of the tooth pulp tissue on the 30th day of the experiment.Conclusion. As a result of an experimental study of the developed dental therapeutic preparation for the treatment of deep caries and acute focal pulpitis, there was established a specific and multifunctional property in preventing and prophylaxis of the inflammation development and enhancing the protective properties of the pulp tissue under the influence of this preparation.Morphological evaluation of the application of the developed dental treatment pad showed a rapid arrest of the inflammatory response of the pulp tissue within 30 days and the normalization of the main components of the tooth pulp.Developed during the conducted experimental research dental therapeutic preparation confirmed its stated properties, in particular, anti-inflammatory, antiseptic, analgesic, moreover, it is not inferior in its properties to the drugs presented in the course of the experimental study.

Partial molar surface areas in liquid mixtures. Theory and evaluation in aqueous ethanol

Different definitions for the partial molar surface area (PMSA) of a mixture component are found in the literature. The advanced definition states that it is the change of surface area resultant from the addition of 1 mol of that component to the surface region at constant temperature, T, pressure, p, surface tension and surface amounts of the other components. Estimating this quantity has long been hampered by the fact that a change of composition while holding constant the mixture surface tension cannot be attained in the laboratory. Using formal thermodynamics, a rigorous procedure for the calculation of PMSAs is worked out. As input, it only requires experimentally measurable properties of liquid mixtures and their pure constituents. This PMSA is shown to be comparable to the PMSA defined in terms of Gibbs surface excesses of the components, though not equivalent to the PMSA for changes in composition at fixed T and p only. From their relationship it is argued that the advanced PMSA is made up of two contributions, namely the area alteration at constant T and p, which leads to a change in the mixture surface tension, and an additional area variation for restoring the initial surface tension value. In a binary liquid mixture, the restoring area is necessarily positive for the surface active component and negative for the solvent. A new, robust thermodynamic derivative is used for the calculation of relative adsorptions and molar surface areas. Expressions are obtained for the analytic calculation of different PMSAs in thermodynamically ideal liquid mixtures. Standard molar surface areas are defined, and expressions are given for their calculation from model or experimental quantities. Real and ideal PMSAs of water and ethanol are estimated in their mixtures at 298 K, using literature data. Thermodynamic consistency tests were developed and used to reject some PMSA values in water-rich and ethanol-rich solutions. This unfortunate situation is ascribed to calculation procedures that impose much stress on the experimental data. It is concluded that Rusanov's interpretation of a PMSA as a restoring area only accounts for a small part of this quantity, at least in aqueous ethanol solutions. The surface structure of water + ethanol mixtures is re-examined at the light of PMSA values.

The sea-air CO2 net fluxes in the South Atlantic Ocean and the role played by Agulhas eddies

The South Atlantic Ocean is vitally important to the global overturning circulation, which is influenced by heat, salt and other properties carried by Agulhas eddies. However, this influence is not yet fully understood, mainly in the context of the biogeochemistry changes on the CO2 system. This study uses in situ data obtained during the Following Ocean Rings in the South Atlantic cruise, which occurred between Cape Town, South Africa and Arraial do Cabo, Brazil in July 2015 when six eddies and the surrounding waters were sampled. The seawater and atmospheric CO2 molar fraction, surface temperature and salinity were continuously measured to calculate the oceanic and atmospheric CO2 partial pressures (pCO2sw and pCO2atm, respectively). This study investigated the role played by the Agulhas eddies in the sea-air CO2 net flux (FCO2) and modeled the seawater CO2 as a function of environmental parameters. The mean pCO2sw and pCO2atm for the entire region were 351.5 and 390.6 μatm, respectively. The mean difference (ΔpCO2) was −39.1 μatm. The CO2 uptake was dominated by temperature (r = 0.88) during the period analyzed. The mean FCO2 was −3.76 and −3.62 mmol m−2d−1 using two different KT-models. We show that an Agulhas eddy can contribute to an ocean uptake of −3.16 kgCO2d−1, leading to the capture of approximately 2.52 tCO2lifetime−1. Thus, providing evidence that the Agulhas eddies propagation can likely play a key role on the rapid seawater acidification of the South Atlantic Central Water. A multiple linear regression model was developed that could reliably reconstruct the cruise survey with better results than previously published.

The molar surface Gibbs energy and its application to the binary mixtures of N-butylpyridinium dicyanamide [C4py][DCA] with alcohols

Abstract The density and surface tension for the binary mixtures of ionic liquid (IL) [C4py][DCA] with ethanol, 1-propanol and 2-propanol were measured across the entire range of mole fraction (x1 = 0.0000–1.0000) at T = (288.15–318.15) K. The average molar volume and the thermal expansion coefficient of the binary mixtures were calculated from the experimental density. The excess molar volumes, VE, of the binary mixtures were also calculated and well fitted by Redlich−Kister equation. The obtained VE are negative values over the whole composition range. The values of VE are related to the alcohol chain length and temperature. In order to predict the surface tension of the mixtures, the new function – the molar surface Gibbs energy of mixtures was obtained from Li’s model improved by us in this work. So, the molar surface Gibbs energy, gs, and its excess function, gsE, of mixtures for [C4py][DCA] with ethanol, 1-propanol and 2-propanol were calculated. The excess molar surface Gibbs energy, gsE, was well fitted by Redlich−Kister equation. In terms of the Redlich−Kister’s parameters, a new method for predicting the surface tension, γ, of the mixtures is proposed and the predicted values, γ (pre.), are in good agreement with the corresponding experimental ones, γ(exp.). On a basis of molar surface Gibbs energy of mixtures, a new Eӧtvӧs equation was obtained and applied to binary mixtures of [C4py][DCA] with alcohols. The absolute value of the slope of the new Eotvos equation is the mole surface entropy, s, and the intercept is the molar surface enthalpy, h, which is temperature-independent.