Electrolyte Solutions and Osmotic Coefficient of [BMIM][BF4] Ionic Liquid Using New GV-SAFT-MSA Equation of State

In this work “Statistical Association Fluid Theory (SAFT)” Equation Of State (EOS) is applied for activity coefficient of electrolyte solution. For considering the presence of ions Mean Spherical Approximation (MSA) term is added to SAFT EOS. The SAFT EOS can predict the thermodynamic properties of associating fluids like H2O and by adding the MSA term, the thermodynamic properties of electrolyte solutions can be obtained. In this work a new term for hard-sphere reference fluid is used. The proposed model has three adjustable parameters. In this the work correlation of activity coefficient for 14 electrolyte solutions is considered. The results show that the proposed model can correlate very well the activity coefficient. The proposed model can also correlate better than Pitzer model the osmotic coefficient of ionic liquid solution [BMIM][BF4] as an organic salt at different temperatures.