Prediction of surface tension of ionic liquids by molecular approach (original) (raw)
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Applying a QSPR correlation to the prediction of surface tensions of ionic liquids
Ionic liquids (ILs) have attracted large amount of interest due to their unique properties. Although large effort has been focused on the investigation of their potential application, characterization of ILs properties and structure–property relationships of ILs are poorly understood. Computer aided molecular design (CAMD) of ionic liquids (ILs) can only be carried if predictive computational methods for the ILs properties are available. The limited availability of experimental data and their quality have been preventing the development of such tools. Based on experimental surface tension data collected from the literature and measured at our laboratory, it is here shown how a quantitative structure–property relationship (QSPR) correlation for parachors can be used along with an estimation method for the densities to predict the surface tensions of ILs. It is shown that a good agreement with literature data is obtained. For circa 40 ionic liquids studied a mean percent deviation (MPD) of 5.75% with a maximum deviation inferior to 16% was observed. A correlation of the surface tensions with the molecular volumes of the ILs was developed for estimation of the surface tensions at room temperature. It is shown that it can describe the experimental data available within a 4.5% deviation. The correlations here developed can thus be used to evaluate the surface tension of ILs for use in process design or in the CAMD of new ionic liquids.
Group contribution model for estimation of surface tension of ionic liquids
Chemical Engineering Science, 2012
c A reliable group contribution method is presented for estimation of surface tension of ionic liquids. c It employs a total of 19 sub-structures plus temperature to predict the surface tension of 51 ionic liquids. c Results of this method show an average absolute relative deviation of 3.6% from experimental data.
Environment, Development and Sustainability, 2021
The surface tension (ST) of ionic liquids (ILs) and their accompanying mixtures allows engineers to accurately arrange new processes on the industrial scale. Without any doubt, experimental methods for the specification of the ST of every supposable IL and its mixtures with other compounds would be an arduous job. Also, experimental measurements are effortful and prohibitive; thus, a precise estimation of the property via a dependable method would be greatly desirable. For doing this task, a new modeling method according to artificial neural network (ANN) disciplined by four optimization algorithms, namely teaching-learning-based optimization (TLBO), particle swarm optimization (PSO), genetic algorithm (GA) and imperialist competitive algorithm (ICA), has been suggested to estimate ST of the binary ILs mixtures. For training and testing the applied network, a set of 748 data points of binary ST of IL systems within the temperature range of 283.1-348.15 K was utilized. Furthermore, an outlier analysis was used to discover doubtful data points. Gained values of MSE & R 2 were 0.0000007 and 0.993, 0.0000002 and 0.998, 0.0000004 and 0.996 and 0.0000006 and 0.994 for the ICA-ANN, TLBO-ANN, PSO-ANN and GA-ANN, respectively. Results demonstrated that the experimental data and predicted values of the TLBO-ANN model for such target are wholly matched.
Ionic liquids surface tension prediction based on enthalpy of vaporization
Fluid Phase Equilibria, 2013
Ionic liquids (ILs) have attracted large amount of interest due to their unique properties. Large effort has been focused on the investigation of their potential application, characterization of ILs properties and structure-property relationships. In this paper a simple equation has been used to prediction the surface tensions of pure ionic liquids based on enthalpy of vaporization. Acentric factor, critical temperature, and critical pressure of ionic liquids are necessary inputs for this prediction. The average relative error obtained from the comparison of experimental and calculated surface tension values for studied ionic liquids are less than 2%. Therefore, the model has good accuracy in comparison with other predictive equations.
Surface Tension of Ionic Liquids Analogues Using the QSPR Correlation
International Journal of Chemical Engineering and Applications, 2013
Deep eutectic solvents (DESs) are mixture complexes being introduced in many applications due to their favorable physicochemical characteristics. However, due to the lack of experimental data, prediction of their physical properties is challenging. One of the important physical properties that provides considerable insight of the molecular influence on intensity of interactions in the mixture is the surface tension. In this work, the QSPR prediction method was employed to predict the DESs surface tension. The parachors of selected DESs based on ammonium and phosphunium salts were determined experimentally and also calculated from the molecular structure of their constituting components using available parachor contribution data for neutral compounds. The results showed that the calculated and experimental parachors of DESs were notably comparable and the parachor contribution data developed for neutral compounds can be successfully utilized for DESs. The calculated parachors were employed to predict the surface tension using their experimental densities values.
The calculation of the surface tension of ordinary organic and ionic liquids, based on a computer algorithm applying a refined group-additivity method, is presented. The refinement consists of a complete breakdown of the molecules into their constituting atoms, further distinguishing them by their immediate neighbour atoms and bond constitution. The evaluation of the atom-groups’ contributions was carried out by means of a fast Gauss-Seidel fitting method founded upon the experimental data of 1895 compounds from literature. The result has been tested for plausibility using a 10-fold cross-validation (cv) procedure. The direct calculation and the cv test proved the applicability of the present method by the close similarity and excellent goodness of fit R2 and Q2 of 0.9023 and 0.8821, respectively. The respective standard deviations are ±2.01 and ±2.16 dyn/cm. Some correlation peculiarities have been observed in a series of ordinary and ionic liquids with homologo...
Molecules
The calculation of the surface tension of ordinary organic and ionic liquids, based on a computer algorithm applying a refined group-additivity method, is presented. The refinement consists of the complete breakdown of the molecules into their constituting atoms, further distinguishing them by their immediate neighbour atoms and bond constitution. The evaluation of the atom-groups' contributions was carried out by means of a fast Gauss-Seidel fitting method, founded upon the experimental data of 1893 compounds from literature. The result has been tested for plausibility using a 10-fold cross-validation (cv) procedure. The direct calculation and the cv test proved the applicability of the present method by the close similarity and excellent goodness of fit R 2 and Q 2 of 0.9039 and 0.8823, respectively. The respective standard deviations are ±1.99 and ±2.16 dyn/cm. Some correlation peculiarities have been observed in a series of ordinary and ionic liquids with homologous alkyl chains, as well as with di-and trihydroxy-groups-containing liquids, which have been discussed in detail, exhibiting the limit of the present method.
Thermochimica Acta, 2014
The recent continuing interest in deep eutectic solvents (DES) as ionic liquids analogues and their successful applications in different areas of separation necessities the existence of reliable physical and thermodynamic properties database. The scarcity of data on the physical properties of such solvents, increases the need for their prediction using reliable methods. In this study, first the critical temperatures of eight DES systems have been calculated based on the Eötvos empirical equation using the experimental data of the density and surface tension at various temperatures, then the density and surface tension values of these systems were predicted from the calculated critical temperatures. For the density prediction the Eötvos and Guggenheim equations were combined to introduce a simple power law equation using the estimated critical temperatures from the Eötvos and the Modified Lydersen-Joback-Reid group contribution methods. Finally, the estimated critical temperatures by these two methods were used in the Guggenheim empirical equation to calculate the surface tension of the DES systems. The prediction quality of the two physical properties under investigation were compared and proper recommendations were postulated.
Generalized PSRK Model for Prediction of Liquid Density of Ionic Liquids
Procedia Engineering, 2013
A simple and generalised expression for adjustable parameter for pure ionic liquids in conjunction with predictive-Soave-Redlich-Kwong (PSRK) approach is presented for prediction of pure IL density. The proposed expression is based on the correlation developed by Nasrifar and Moshfeghian for perfection of saturated liquid density for pure compounds. The generalized expression uses acentric factor and mass connectivity index of pure ionic liquids. A set of 47 pure ionic liquids with 735 data points and 4 different cohesion functions were used in the study. The results were compared with linear generalized model (LGM) developed by Valderrama to check appropriateness and accuracy of expression presented. It was found that the compound specific PSRK approach gives very accurate predictions and generalized expression is at par with LGM model. Further study would include use of other cohesion factor models.