Search for: mean-spherical-approximation
Activity coefficient prediction for binary and ternary aqueous electrolyte solutions at different temperatures and concentrations, Article Journal of Solution Chemistry ; Volume 41, Issue 1 , 2012 , Pages 75-88 ; 00959782 (ISSN) ; Ghotbi, C ; Abdekhodaie, M. J ; Sharif University of Technology
The mean spherical approximation (MSA) model, coupled with two hard sphere models, was used to predict the activity coefficients of mixtures of electrolyte solutions at different temperatures and concentrations. The models, namely the Ghotbi-Vera-MSA (GV-MSA) and Mansoori et al.-MSA (BMCSL-MSA), were directly used without introducing any new adjustable parameters for mixing of electrolyte solutions. In the correlation step, the anion diameters were considered to be constant, whereas the cation diameters were considered to be concentration dependent. The adjustable parameters were determined by fitting the models to the experimental mean ionic activity coefficients for single aqueous...
The MSA and the individual ionic activity coefficients, Article Iranian Journal of Science and Technology, Transaction B: Technology ; Volume 27, Issue 2 , 2003 , Pages 247-252 ; 03601307 (ISSN) ; Modarress, H ; Khoshkbarchi, M. K ; Vera, J. H ; Sharif University of Technology
The mean spherical approximation (MSA) has been applied to accurately correlate the activity coefficients of individual ions in aqueòus solutions of single 1:1 electrolytes. In order to account for changes in the hydration of the ions, the size parameters of the ions are considered to be composition dependent. The values of the size parameters show that the hydration of the ions decreases as the electrolyte concentration increases. Results obtained from the full MSA and from a simplified version of MSA (SMSA), were compared. The use of the simplified version had a small effect on the final results and dramatically reduced the computation of the effort
Application of the non-primitive MSA-based models in predicting the activity and the osmotic coefficients of aqueous electrolyte solutions, Article Fluid Phase Equilibria ; Volume 221, Issue 1-2 , 2004 , Pages 189-196 ; 03783812 (ISSN) ; Ghotbi, C ; Taghikhani, V ; Azimi, G ; Sharif University of Technology
The non-primitive mean spherical approximation (NP-MSA) based models were used to correlate the individual and the mean ionic activity coefficients of the symmetric and asymmetric aqueous electrolyte solutions. The results of the models for the mean ionic activity coefficients were directly used to calculate the osmotic coefficient for the electrolyte solutions studied in this work. In the NP-MSA models, the Ghotbi-Vera and the Boublik-Mansoori-Carnahan-Starling- Leland hard sphere equation of state as the reference system coupled with the non-primitive mean spherical approximation model (NP-GV-MSA and NP-BMCSL-MSA models, respectively). In correlating the mean ionic activity coefficients of...
Modification of the GV-MSA model in obtaining the activity and osmotic coefficients of aqueous electrolyte solutions, Article Fluid Phase Equilibria ; Volume 240, Issue 2 , 2006 , Pages 167-172 ; 03783812 (ISSN) ; Taghikhani, V ; Ghotbi, C ; Sharif University of Technology
In this work a modified form of the Ghotbi-Vera Mean Spherical Approximation model (MGV-MSA) has been used to correlate the mean ionic activity coefficients (MIAC) for a number of symmetric and asymmetric aqueous electrolyte solutions at 25 °C. In the proposed model the hard sphere as well as the electrostatic contributions to the MIAC and the osmotic coefficient of the previously GV-MSA model has been modified. The results of the proposed model for the MIAC of the electrolyte solutions studied in this work are used to directly calculate the values of the osmotic coefficients without introducing any new adjustable parameter. In the MGV-MSA model the cation diameter as well as the relative...
Application of the MSA-based models in correlating the surface tension for single and mixed electrolyte solutions, Article Journal of Chemical Thermodynamics ; Volume 41, Issue 11 , 2009 , Pages 1264-1271 ; 00219614 (ISSN) ; Taghikhani, V ; Ghotbi, C ; Sharif University of Technology
Experimental values for surface tension of single and mixed electrolyte solutions were correlated using the models based on the perturbation theory. The Mean Spherical Approximation (MSA) model, coupled with the Ghotbi-Vera (GV) and the Mansoori et al. (BMCSL) equations of state, were used to correlate the experimental values of the surface tension. The results showed that the models can favourably correlate the experimental values for single electrolyte solutions. However, it was observed that the GV-MSA model can more accurately predict the surface tension for single electrolytes, especially at higher concentrations. Two different expressions for concentration dependency of cation hydrated...
A new model in correlating the activity coefficients of aqueous electrolyte solutions with ion pair formation, Article Fluid Phase Equilibria ; Volume 261, Issue 1-2 , December , 2007 , Pages 313-319 ; 03783812 (ISSN) ; Taghikhani, V ; Ghotbi, C ; Sharif University of Technology
In this work, the Ion Pair Modified Ghotbi-Vera Mean Spherical Approximation (IP-MGV-MSA) model was proposed to correlate the mean ionic activity coefficients (MIAC) for a number of symmetric and asymmetric aqueous electrolyte solutions at 25 °C. The new model is based on the recently proposed MGV-MSA model by Mortazavi-Manesh et al. In the IP-MGV-MSA model, the effects arising from the ion pair formation in the electrolyte solution was taken into account. Also, in the proposed model, while the cation diameter as well as the relative permittivity of water was considered to be dependent on electrolyte concentration, the anion diameter was independent of electrolyte concentration. The results...